Primary syphilis: a histological and immunohistochemical evaluation

Primary syphilis: a histological and immunohistochemical evaluation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research article Primary syphilis: a histological and immunohistochemical evaluation Ling Leng, Hui Zi Gong, Tao Wang, He Yi Zheng, Jun Li This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.2.24783/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Syphilitic chancre could be misdiagnosed as other skin diseases and a biopsy is sometimes done before serological testing, which makes it essential to find possible primary syphilis patients through histopathology and immunohistochemistry (IHC). Method: We sought to determine the histopathological and IHC characteristics in primary syphilis. Eleven biopsy specimens were collected from 9 patients diagnosed with primary syphilis. Specimens were analyzed for T. pallidum using antibody to T. pallidum . We also compared IHC results with the histological characteristics. Results: In our study, plasma cells infiltration was the most common pattern [90.9% (10/11)] in primary syphilis. Necrotic keratinocytes could be observed in 54.5% (6/11) of primary syphilis. T. pallidum was discovered in 9 of 10 (90.0%) primary syphilis by IHC. T. pallidum is mainly detected in the medium to superficial dermis and the lower epidermis regions. In the dermis area, T. pallidum was discovered mainly around the perivascular regions. Conclusion: Although serological tests remain the gold standard for the confirming diagnosis of syphilis infection, Histopathological and IHC could be helpful in the diagnosis of some syphilitic patients when serologic testing is not capable of detecting T. pallidum antibodies in serum. Using IHC technique allows us to precisely find out the location of the microorganism in the syphilitic skin lesions. Infectious Diseases Primary syphilis Histological features Immunohistochemistry Treponema pallidum Figures Figure 1 Figure 2 Background Syphilis is a multistage sexually transmitted disease (STD) due to Treponema pallidum subsp pallidum ( T. pallidum ). Syphilis remains a major health problem throughout the world and can cause genital ulceration that may enhance the risk of transmission and acquisition of human immunodeficiency virus (HIV). Vertical transmission of T. pallidum could cause congenital syphilis. In China, syphilis has increased dramatically during the last three decades, and the average annual increase in the incidence of syphilis has been as high as 16.3%. 1 According to infectious course, syphilis can be divided into three main stages: primary, secondary, and tertiary. If untreated, about 1/3 primary syphilitic cases will progress to secondary syphilis. Diagnosis of syphilis during the primary stage is particularly important, since appropriate treatment can prevent the development of secondary stage and chronic disease stage. T. pallidum is usually identified by dark field microscopy and by serologic test. However, false negative or false positive result of microscopy testing often occurs when laboratory staffs lack of experiences to distinguish T. pallidum from other bacteria. Serologic test for syphilis involves serological assays based on nontreponemal antibody [Serologic tests for syphilis reveal the individual's immunologic status, but not whether the patient is currently infected. Because these tests use lipoidal antigens rather than T. palliduin or components of it, they are called nontreponemal ailtigen tests. Most widely used are Venereal Disease Research Laboratory or rapid plasma regain (RPR)] and treponemal antibody [fluorescent treponemal antibody absorption (FTA-ABS) or T. pallidum particle agglutination (TPPA)/ T. pallidum hemagglutination assay (TPHA)] responses. Serological testing for syphilis is now recognized as reliable methods for confirmation of the diagnosis and the reliable methods to evaluate the preliminary efficacy of the treatment. However, the results of serologic tests for syphilis are only positive in 50% (nontreponemal tests) to 90% (treponemal tests) of patients with primary syphilis. The likelihood of positivity depends on the duration of infection. Furthermore, false negative serological testing result has been reported previously in early syphilis/HIV co-infection or in prezone phenomenon (Patients with very high antibody titers, as occur in secondary syphilis, may have a false negative result when undiluted serum is tested. This prozone phenomenon will be overcome by diluting the serum). Primary syphilitic chancre could be misdiagnosed as other skin diseases and a skin biopsy is sometimes done before serum testing, which makes it essential to dignosis atypical syphilis cases through skin histopathology. However, histopathological features (such as plasma cells) sometimes may be sparse and even absent, and silver stain, such as the Warthin Starry, or Levaditi methods is often negative ( T. pallidum are usually found by the silver stain method. However, silver stain method is characterized by obvious background artifacts). Silver staining could discover spirochetes, but it is nonspecific to T. pallidum . Warthin Starry (silver stain method) may be hard to discover skin lesions in non-treponemal spirochete contaminated locations. We need to find a better method to detect spirochete in tissue. IHC directed anti- T. pallidum antibodies achieves significantly improved overall specificity and sensitivity. 2,3 In our study, a polyclonal antibody to T. pallidum was used to directly and specifically detect T. pallidum in skin lesions from patients with primary syphilis and we also compared IHC results with histological features. Methods Using our written and electronic medical records, 11 skin biopsy tissue specimen from 9 cases diagnosed with primary syphilis according to clinical presentation, serological testing results and follow-up serological testing results between 2008 and 2018 were obtained from the STD Center of Peking Union Medical College Hospital, China. All methods were carried out in accordance with the relevant guidelines and regulations. Written informed consent was obtained from all participantsThis study was approved by the institutional review boards of the Peking Union Medical College Hospital (reference number S-K653). Primary syphilis was defined by the presence of genital ulcers and/or inguinal lymphadenopathy, confirmed to be positive for T. pallidum in clinical specimens by RPR and TPHA/TPPA, and/or FTA-ABS. Once the diagnosis was confirmed, three doses of penicillin G benzathine, 2.4-MU intramuscular each, separated by one week was given to the patient. The clinical data including the patient’s age, sex, skin lesions, HIV status, syphilis serological testing results, treatment and follow-up results were obtained from the medical record. The hematoxylin and eosin staining sections were reviewed and the histopathological diagnoses confirmed. A panel of histopathological features was evaluated blindly by two certified dermatologists, both of them were fully trained in dermatopathology. The cases were classified as lacking or having the following histological features: plasma cells (Fig. 1 . A); endothelial swelling (Fig. 1 . B); interstitial patterns of inflammation; elongated rete ridges; irregular acanthosis; vacuolar pattern of inflammation; lymphocytes with ample cytoplasm; neutrophils in the stratum corneum; lichenoid pattern of inflammation; keratinocyte apoptosis (Fig. 1 . C and D). Formalin-fixed paraffin-embedded tissues were sliced into 4-micrometer thick sections. To detect T. pallidum , the avidin biotin peroxidase complex technique was used. After heat induced epitope retrieval and primary rabbit polyclonal antibody directed to T. pallidum (Novus Biologicals, Inc., CA, USA). For comparison, 3 cases that were negative for syphilitic serum testing but histological manifestations were similar to primary syphilis were included: two case of balanitis, one case of lichen sclerosus et atrophicus. Results Clinical and IHC results of the 10 specimens are summarized in Table 1 . The histologic features of the 11 sections are summarized in Table 2 . All the patients also had clinical pictures. One patient had biopsies done at 2 different anatomical sites (Cases 5 and 6). One patient had skin biopsies done at different times [Cases 9 and 10 (two weeks later)]. The female to male ratio was 3:6. The age of the patients ranged from 19 to 58 years. All patients were negative for HIV virus. One patient (Cases 5 and 6) also had secondary syphilis at the same time. Three patients (Cases 1, 9/10, and 11) also tested positive to FTA-ABS-IgM. All patients exhibited sero-reversion within 12 months after treatment (Table 3 ). Table 1 Clinical features and detection of T. pallidum in primary syphilis cases Case Age Prebiopsy differential IHC⇐ Localization‡ Biopsy location Skin lesion location Skin Lesion Duration¶ No.† 1 35–40 Ulcer Dense Lower epidermis, dermo-epidermal, dermis (mainly perivascular ) areas Coronary sulcus Glans Ulcer 3 1 2 55–60 Extramammary Paget's disease Dense Median and deep dermis, perivascular areas Penis Root of the penis Ulcer 6 1 3 30–35 Mammary Paget's disease Sparse Lower epidermis Left nipple Left nipple Scaly erythema 12 1 4 45–50 Extramammary Paget's disease Moderate Lower epidermis, dermo-epidermal and upper dermis areas Penis Penis Erythema and ulcer 8 1 5 15–20 Mammary Paget's disease Dense Lower epidermis, dermo-epidermal, dermis (mainly perivascular ) areas Left nipple Bilateral nipples Erythema and erosion 8 2 6 15–20 Mammary Paget's disease Dense Lower epidermis, dermo-epidermal, dermis (mainly perivascular ) areas Right nipple Bilateral nipples Erythema and erosion 8 2 7 35–40 Ulcer Moderate Dermo-epidermal, perivascular (upper dermis) areas Glans Glans and right scrotum Ulcer 2 2 8 55–60 Behcet's disease Moderate Lower epidermis, dermo-epidermal and upper dermis areas Penis Penis and scrotum Ulcer 16 3 9 40–45 Eczema Dense Dermo-epidermal, dermis (mainly perivascular ) areas Left nipple Left nipple Erythema, erosion and crust 2 1 10 40–45 Eczema Negative Negative Left nipple Left nipple Erythema, erosion and crust 4 1 11 35–40 Scabies NA NA Penis Root of the penis Nodules 12 2 ⇐Immunohistochemistry, Bacteria were detected by using polyclonal antibody directed against T. pallidum in parraffin-embedded biopsy samples by IHC technique as described in Methods. A representative recognition pattern of T. pallidum is presented in Figures. ‡ Spirochete immunostain location. A representative recognition pattern of T. pallidum is presented in Figures. ¶ Primary syphilitic lesions lasted for weeks. † Number of Chancres. Abbreviations: F, female; M, male; RPR, rapid plasma regain. Table 2 Histological features of the 11 sections Case Plasma cells Endothelial swelling Interstitial inflammation Irregular acanthosis Elongated rete ridges Vacuolar pattern Lymphocytes with ample cytoplasm Neutrophils in stratum corneum Lichenoid pattern Necrotic keratinocytes 1 + + - - - + + + + - 2 - - + - - - + + - - 3 + + + + + + + + + + 4 + + - + + + + + + + 5 + + + + + + + + - + 6 + + + + + + + + - + 7 + + + - - + + - + - 8 + + - + + + + + + + 9 + + + + + + + + + + 10 + + + - - - + + - - 11 + + + - - - + - - - Positive detection (+), Negative detection (-). Table 3 Follow-up results after treatment Case RPR Titer HIV TPPA/TPHA FTA-ABS-IgG FTA-ABS-IgM Follow-up Months¶ 1 0 N P P P Lost 2 1:8 N P - - Cured 4 3 ≥ 1:32 N P - - Cured 12 4 ≥ 1:32 N P - - Cured 12 5 ≥ 1:32 N P - - Cured 9 6 ≥ 1:32 N P - - Cured 9 7 1:1 N P - - Lost 8 ≥ 1:32 N P - - Cured 6 9 1:8 N P P P Cured 6 10 1:8 N P P P Cured 6 11 0 N P P P Cured 5 ¶ sero-reversion time; N, negative; P, positive Eleven biopsies with primary syphilis were included in the histologic analysis. In primary syphilis, plasma cells infiltration [90.9% (10/11)] was the most common pathologic characteristics (Table 2 and Fig. 1 . A). We also noted that necrotic keratinocytes could be observed in 54.5% (6/11) primary syphilis cases (Table 2 and Fig. 1 . C and D). The specimens analyzed by IHC were shown in Table 1 . Micro-organisms were discovered in 9 of 10 (90.0%) specimens from cases with primary syphilis and were not detected in the control sections. T. pallidum were seen in all positive patients as typical spiral and thread-like organisms highlighted by red chromogen. The micro-organism is mainly detected in the medium to superficial dermis and the lower epidermis regions (Fig. 2 , A). In the dermis area, the micro-organism was discovered mainly in the perivascular region (Fig. 2 , B). The quantity of the bacteria varied with only a few T. pallidum (sparse, Fig. 2 , C), a moderate amount (moderate) and a large amount (dense, Fig. 2 , D). Discussion Clinically, primary syphilis can present as other ulcerative dermatosis. Histologically, the same applies. In our study, plasma cells infiltration (90.9%) was the most common pattern. It is appear that plasma cells play an important role in the pathophysiology of primary syphilis. Further research could include IHC stain of CD138/38, so as to detect the plasma cells neglected in hematoxylin and eosin staining sections. Necrotic keratinocytes could be detected in 54.5% of primary syphilis patients. Similarly, previous studies also showed that ulcerative lesions covered by necrotic material and cellular debris were most observed in primary syphilis. 4−5 Dilated blood vessels with swelling endothelial cells is generally considered to be a phenomenon of early syphilis. 6 These findings are explained with the IHC findings that T. pallidum was discovered mainly in the perivascular and vascular region in the dermis area. Our study result is in accordance with the previous animal experiment which find T. pallidum localizing to vascular and perivascular regions in all the courses of infection in the infected rabbit testicular tissue samples. 7 According to literature report, T. pallidum is attachment to the endothelial lining of blood vessels, migration of T. pallidum between the junctions of vascular endothelium cells. 8,9 . In our study, we have found that the micro-organism is mainly detected in the dermo-epidermal areas in epidermis and lower part of epidermis. In the dermis, the micro-organism was detected mainly in the medium and superficial perivascular region where a notable inflammatory response was in place. Up to now, there is still no reasonable explanation for upper dermal and the epidermal distribution of the micro-organism where it should be killed by our immune system. Previous study showed that early stage syphilitic skin lesions have a characteristic increased T-suppressor lymphocytes acting as closing a innate immune response and causing the persistence of the micro-organism in these lesions. 10 The other possible reason is that the T. pallidum adhesin Tp0751 was previously shown to bind laminin, the most abundant component of the basement membrane, 11 suggesting T. pallidum in host tissue colonization. 12−14 Conclusion The usual technique for detecting T. pallidum in tissue samples is through Warthin-Starry (silver staining method). Obvious background artifacts are common, as the Warthin-Starry highlights melanin granules also and reticulin fibers causing it difficult to detect the T. pallidum . Our study focused on the evaluation of T. pallidum in primary syphilis by IHC and compared IHC with histologic features. We discovered the presence of T. pallidum in 90.0% of primary syphilitic patients. It is still unknown what proportion of primary syphilis escape this testing method. The capability of T. pallidum escaping our immune system is largely unknown and the distribution of T. pallidum in the lesion could bring us some clues to figure out its pathogenesis. Declarations Ethical Approval and Consent to participate: This study was approved by the institutional review boards of the Peking Union Medical College Hospital (reference number S-K653). All patients consent to participate in this study. Consent for publication: Written consent for publication have obtained from patients. Informed consent was obtained from all subjects. Availability of data and materials: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests: None reported. Funding/Support: Supported by Beijing Municipal Science and Technology Commission No. Z191100006619011.We declare that we have no conflicts of interest. We declare that the paper has not been submitted to another journal, and has not been published in whole or in part elsewhere previously. Authors' contributions: Dr Jun Li and Dr He Yi Zheng had full access to all data in the study and take responsibility for the integrity of data and accuracy of data analysis, as well as for the study concept and design. All the authors take responsibility for acquisition, analysis, and interpretation of the data. Ling Leng takes responsibility for drafting of the manuscript. Drs Tao Wang, and Hui Zi Gong take responsibility for critical revision of the manuscript for important intellectual content. Ling Leng was responsible for technical support. Acknowledgements: We thank the colleagues in the Department of dermatology, Peking Union Medical College Hospital for partially supporting this study and also the general patients included in the study. Authors: Ling Leng,* Hui Zi Gong*, MD, Tao Wang, MD, He Yi Zheng, MD, Jun Li, MD *co-first authors Author Affiliations: Department of Medical Science Research Center (Ling Leng), Department of Dermatology (H Z Gong, T Wang, H Y Zheng, J Li), Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 100730 Correspondence to: Dr Jun Li, Department of Dermatology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. No.1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, China, 100730 email address： [email protected] Telephone number：086-010-69151502 References Yang S, Wu J, Ding C, et al. Epidemiological features of and changes in incidence of infectious diseases in China in the first decade after the SARS outbreak: an observational trend study. Lancet Infect Dis. 2017;17(7):716-725. Quatresooz P, Piérard GE. Skin homing of Treponema pallidum in early syphilis: an immunohistochemical study. Appl Immunohistochem Mol Morphol. 2009;17(1):47-50. Buffet M, Grange PA, Gerhardt P, et al. Diagnosing Treponema pallidum in secondary syphilis by PCR and immunohistochemistry. J Invest Dermatol. 2007;127(10):2345-2350. Engelkens HJ, ten Kate FJ, Vuzevski VD, van der Sluis JJ, Stolz E. Primary and Secondary Syphilis: A Histopathological Study. International Journal of STD & AIDS. 1991; 2: 280-284. Martín-Ezquerra G, Fernandez-Casado A, Barco D, Jucglà A, Juanpere-Rodero N, Manresa JM. Treponema pallidum distribution patterns in mucocutaneous lesions of primary and secondary syphilis: an immunohistochemical and ultrastructural study. Hum Pathol. 2009; 40: 624-630. Sangüenza O, Fleet S, Requena L. Histologic findings of cutaneous infections. Adv Dermatol. 2000;16:361-423. Lukehart SA, Baker-Zander SA, Lloyd RM, Sell S. Characterization of lymphocyte responsiveness in early experimental syphilis. II. Nature of cellular infiltration and Treponema pallidum distribution in testicular lesions. J Immunol. 1980;124(1):461-467. Fitzgerald TJ, Miller JN, Sykes JA. Treponema pallidum (Nichols strain) in tissue cultures: cellular attachement, entry and survival. Infect Immun. 1975;11(5):1133-1140. Thomas DD, Navab M, Haake DA, et al. Treponema pallidum invades intercellular junctions of endothelial cell monolayers. Proc Natl Acad Sci USA.1988;85(10):618-624. Engelkens HJ, ten Kate FJ, Judanarso J, et al. The localisation of treponemes and characterisation of the inflammatory infiltrate in skin biopsies from patients with primary or secondary syphilis, or early infectious yaws. Genitourin Med. 1993;69(2):102-107. Bruckner Tuderman L. Biology and pathology of the skin basement membrane zone. Matrix Biol. 1999;18(1):3-4. Cameron CE. Identification of a Treponema pallidum laminin-binding protein. Infect Immun. 2003;71(5):2525-2533. Cameron CE, Brouwer NL, Tisch LM, Kuroiwa JM. Defining the interaction of the Treponema pallidum adhesin Tp0751 with laminin. Infect Immun. 2005;73(11):7485-7494. Cameron CE, Kuroiwa JM, Yamada M, et al. Heterologous expression of the Treponema pallidum laminin-binding adhesin Tp0751 in the culturable spirochete Treponema phagedenis. J Bacteriol. 2008;190(7):2565-2571. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-15341","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":373840,"identity":"8dc32a9c-2260-49e8-886c-b68517ce9955","order_by":1,"name":"Ling Leng","email":"","orcid":"","institution":"Peking University People's Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ling","middleName":"","lastName":"Leng","suffix":""},{"id":373841,"identity":"8d65194e-5fdb-4f00-887b-b93458eb4406","order_by":2,"name":"Hui Zi Gong","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Hui","middleName":"Zi","lastName":"Gong","suffix":""},{"id":373842,"identity":"ec4df0c4-2677-4c0c-9da6-516fa1fe9a7a","order_by":3,"name":"Tao Wang","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Tao","middleName":"","lastName":"Wang","suffix":""},{"id":373843,"identity":"65e26489-80c2-4337-92b0-ede7bd82fd95","order_by":4,"name":"He Yi Zheng","email":"","orcid":"","institution":"Peking Union Medical College Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"He","middleName":"Yi","lastName":"Zheng","suffix":""},{"id":373844,"identity":"9618d700-4339-43b8-bf8b-c16b7b7e2ffa","order_by":5,"name":"Jun Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzElEQVRIiWNgGAWjYBACPmaGBAaGH//kDMBcAwvCWthAWhh7DhgbMDCDtEgQoQVCHkjcANbCQIwWdoZn0gU8d9K3s/cf3fCjQIKBv707gZDD0qRnWDzL3dlzmO1mD9BhEmfObiCshYeHOXfDjWS2GzxALQYSucRoYWNONwBqufmHBC2HE0BabhNrS7I1b0+a4YYzh81uyxhI8BD0Cz//mcTbPD9s5A2ONz67+eaPjRx/ey9+LQwMPAmoXALKQYD9ABGKRsEoGAWjYEQDAE01Piyw6WiGAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0003-4820-5251","institution":"Peking Union Medical College Hospital","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Jun","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2020-02-26 12:30:56","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.2.24783/v1","doiUrl":"https://doi.org/10.21203/rs.2.24783/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":563208,"identity":"fd993519-b9fb-4ee4-89cf-6db6d0199836","added_by":"auto","created_at":"2020-02-28 00:58:54","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":6690220,"visible":true,"origin":"","legend":"Histological characteristics of primary syphilis. (A) plasma cellular infiltrating in the upper part of dermis (hematoxylin and eosin, magnification ×200); (B) dilated vessels and endothelial swelling (hematoxylin and eosin, magnification ×200); (C)-(D) keratinocyte apoptosis exhibition scattered bright red cells in epidermis, some of which contain small black pyknotic nuclei (magnification ×200 and ×400).","description":"","filename":"Fig1.A.jpg","url":"https://assets-eu.researchsquare.com/files/cc71143d-44b4-4490-90e5-af116f469fa8/v1/Fig 1. A.jpg"},{"id":563209,"identity":"3a823b49-6375-4c02-a821-6ba877eed0ef","added_by":"auto","created_at":"2020-02-28 00:58:54","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":23634620,"visible":true,"origin":"","legend":"IHC features of primary syphilis. (A) T. pallidum was found in the lower epidermis (magnification ×100); (B) T. pallidum in the perivascular area in the dermis area (magnification ×200); (C) bacteria quantity of sparse (magnification ×150); (D) bacteria quantity of dense (magnification ×60).","description":"","filename":"Fig2.A.jpg","url":"https://assets-eu.researchsquare.com/files/cc71143d-44b4-4490-90e5-af116f469fa8/v1/Fig 2. A.jpg"},{"id":13490997,"identity":"19e2fc18-5a2b-4291-b53d-7fa69fbfca0d","added_by":"auto","created_at":"2021-09-16 22:25:50","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":777129,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-15341/v1/d3cefe07-4991-4199-807d-5d7bb6b750b8.pdf"}],"financialInterests":"","formattedTitle":"Primary syphilis: a histological and immunohistochemical evaluation","fulltext":[{"header":"Background","content":" \u003cp\u003eSyphilis is a multistage sexually transmitted disease (STD) due to Treponema pallidum subsp pallidum (\u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e). Syphilis remains a major health problem throughout the world and can cause genital ulceration that may enhance the risk of transmission and acquisition of human immunodeficiency virus (HIV). Vertical transmission of \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e could cause congenital syphilis. In China, syphilis has increased dramatically during the last three decades, and the average annual increase in the incidence of syphilis has been as high as 16.3%.\u003csup\u003e1\u003c/sup\u003e According to infectious course, syphilis can be divided into three main stages: primary, secondary, and tertiary. If untreated, about 1/3 primary syphilitic cases will progress to secondary syphilis.\u003c/p\u003e \u003cp\u003eDiagnosis of syphilis during the primary stage is particularly important, since appropriate treatment can prevent the development of secondary stage and chronic disease stage. \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e is usually identified by dark field microscopy and by serologic test. However, false negative or false positive result of microscopy testing often occurs when laboratory staffs lack of experiences to distinguish \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e from other bacteria. Serologic test for syphilis involves serological assays based on nontreponemal antibody [Serologic tests for syphilis reveal the individual's immunologic status, but not whether the patient is currently infected. Because these tests use lipoidal antigens rather than \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. palliduin\u003c/span\u003e or components of it, they are called nontreponemal ailtigen tests. Most widely used are Venereal Disease Research Laboratory or rapid plasma regain (RPR)] and treponemal antibody [fluorescent treponemal antibody absorption (FTA-ABS) or \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e particle agglutination (TPPA)/\u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e hemagglutination assay (TPHA)] responses. Serological testing for syphilis is now recognized as reliable methods for confirmation of the diagnosis and the reliable methods to evaluate the preliminary efficacy of the treatment. However, the results of serologic tests for syphilis are only positive in 50% (nontreponemal tests) to 90% (treponemal tests) of patients with primary syphilis. The likelihood of positivity depends on the duration of infection. Furthermore, false negative serological testing result has been reported previously in early syphilis/HIV co-infection or in prezone phenomenon (Patients with very high antibody titers, as occur in secondary syphilis, may have a false negative result when undiluted serum is tested. This prozone phenomenon will be overcome by diluting the serum).\u003c/p\u003e \u003cp\u003ePrimary syphilitic chancre could be misdiagnosed as other skin diseases and a skin biopsy is sometimes done before serum testing, which makes it essential to dignosis atypical syphilis cases through skin histopathology. However, histopathological features (such as plasma cells) sometimes may be sparse and even absent, and silver stain, such as the Warthin Starry, or Levaditi methods is often negative (\u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e are usually found by the silver stain method. However, silver stain method is characterized by obvious background artifacts). Silver staining could discover spirochetes, but it is nonspecific to \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e. Warthin Starry (silver stain method) may be hard to discover skin lesions in non-treponemal spirochete contaminated locations. We need to find a better method to detect spirochete in tissue. IHC directed anti-\u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e antibodies achieves significantly improved overall specificity and sensitivity.\u003csup\u003e2,3\u003c/sup\u003e In our study, a polyclonal antibody to T. pallidum was used to directly and specifically detect \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e in skin lesions from patients with primary syphilis and we also compared IHC results with histological features.\u003c/p\u003e "},{"header":"Methods","content":" \u003cp\u003eUsing our written and electronic medical records, 11 skin biopsy tissue specimen from 9 cases diagnosed with primary syphilis according to clinical presentation, serological testing results and follow-up serological testing results between 2008 and 2018 were obtained from the STD Center of Peking Union Medical College Hospital, China. All methods were carried out in accordance with the relevant guidelines and regulations. Written informed consent was obtained from all participantsThis study was approved by the institutional review boards of the Peking Union Medical College Hospital (reference number S-K653).\u003c/p\u003e \u003cp\u003ePrimary syphilis was defined by the presence of genital ulcers and/or inguinal lymphadenopathy, confirmed to be positive for T. pallidum in clinical specimens by RPR and TPHA/TPPA, and/or FTA-ABS. Once the diagnosis was confirmed, three doses of penicillin G benzathine, 2.4-MU intramuscular each, separated by one week was given to the patient. The clinical data including the patient\u0026rsquo;s age, sex, skin lesions, HIV status, syphilis serological testing results, treatment and follow-up results were obtained from the medical record.\u003c/p\u003e \u003cp\u003eThe hematoxylin and eosin staining sections were reviewed and the histopathological diagnoses confirmed. A panel of histopathological features was evaluated blindly by two certified dermatologists, both of them were fully trained in dermatopathology. The cases were classified as lacking or having the following histological features: plasma cells (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. A); endothelial swelling (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. B); interstitial patterns of inflammation; elongated rete ridges; irregular acanthosis; vacuolar pattern of inflammation; lymphocytes with ample cytoplasm; neutrophils in the stratum corneum; lichenoid pattern of inflammation; keratinocyte apoptosis (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. C and D).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFormalin-fixed paraffin-embedded tissues were sliced into 4-micrometer thick sections. To detect \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e, the avidin biotin peroxidase complex technique was used. After heat induced epitope retrieval and primary rabbit polyclonal antibody directed to \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e (Novus Biologicals, Inc., CA, USA). For comparison, 3 cases that were negative for syphilitic serum testing but histological manifestations were similar to primary syphilis were included: two case of balanitis, one case of lichen sclerosus et atrophicus.\u003c/p\u003e "},{"header":"Results","content":" \u003cp\u003eClinical and IHC results of the 10 specimens are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The histologic features of the 11 sections are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. All the patients also had clinical pictures. One patient had biopsies done at 2 different anatomical sites (Cases 5 and 6). One patient had skin biopsies done at different times [Cases 9 and 10 (two weeks later)]. The female to male ratio was 3:6. The age of the patients ranged from 19 to 58\u0026nbsp;years. All patients were negative for HIV virus. One patient (Cases 5 and 6) also had secondary syphilis at the same time. Three patients (Cases 1, 9/10, and 11) also tested positive to FTA-ABS-IgM. All patients exhibited sero-reversion within 12\u0026nbsp;months after treatment (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cdiv class=\"SimplePara\"\u003eClinical features and detection of \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e in primary syphilis cases\u003c/div\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eCase\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eAge\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003ePrebiopsy differential\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eIHC\u0026lArr;\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eLocalization\u0026Dagger;\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eBiopsy location\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eSkin lesion location\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eSkin Lesion\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003eDuration\u0026para;\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003eNo.\u0026dagger;\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e1\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e35\u0026ndash;40\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eUlcer\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eDense\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eLower epidermis, dermo-epidermal, dermis (mainly perivascular ) areas\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eCoronary sulcus\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eGlans\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eUlcer\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e3\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e1\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e2\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e55\u0026ndash;60\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eExtramammary Paget's disease\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eDense\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eMedian and deep dermis, perivascular areas\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003ePenis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eRoot of the penis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eUlcer\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e6\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e1\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e3\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e30\u0026ndash;35\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eMammary Paget's disease\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eSparse\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eLower epidermis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eLeft nipple\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eLeft nipple\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eScaly erythema\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e12\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e1\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e4\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e45\u0026ndash;50\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eExtramammary Paget's disease\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eModerate\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eLower epidermis, dermo-epidermal and upper dermis areas\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003ePenis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003ePenis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eErythema and ulcer\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e8\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e1\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e5\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e15\u0026ndash;20\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eMammary Paget's disease\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eDense\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eLower epidermis, dermo-epidermal, dermis (mainly perivascular ) areas\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eLeft nipple\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eBilateral nipples\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eErythema and erosion\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e8\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e2\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e6\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e15\u0026ndash;20\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eMammary Paget's disease\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eDense\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eLower epidermis, dermo-epidermal, dermis (mainly perivascular ) areas\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eRight nipple\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eBilateral nipples\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eErythema and erosion\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e8\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e2\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e7\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e35\u0026ndash;40\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eUlcer\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eModerate\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eDermo-epidermal, perivascular (upper dermis) areas\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eGlans\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eGlans and right scrotum\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eUlcer\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e2\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e2\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e8\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e55\u0026ndash;60\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eBehcet's disease\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eModerate\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eLower epidermis, dermo-epidermal and upper dermis areas\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003ePenis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003ePenis and scrotum\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eUlcer\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e16\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e3\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e9\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e40\u0026ndash;45\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eEczema\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eDense\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eDermo-epidermal, dermis (mainly perivascular ) areas\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eLeft nipple\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eLeft nipple\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eErythema, erosion and crust\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e2\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e1\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e10\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e40\u0026ndash;45\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eEczema\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eNegative\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eNegative\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eLeft nipple\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eLeft nipple\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eErythema, erosion and crust\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e4\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e1\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e11\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e35\u0026ndash;40\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eScabies\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eNA\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eNA\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003ePenis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eRoot of the penis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eNodules\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e12\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e2\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"10\"\u003e\u0026lArr;Immunohistochemistry, Bacteria were detected by using polyclonal antibody directed against T. pallidum in parraffin-embedded biopsy samples by IHC technique as described in Methods. A representative recognition pattern of \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e is presented in Figures.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"10\"\u003e\u0026Dagger; Spirochete immunostain location. A representative recognition pattern of \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e is presented in Figures.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"10\"\u003e\u0026para; Primary syphilitic lesions lasted for weeks.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"10\"\u003e\u0026dagger; Number of Chancres.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"10\"\u003eAbbreviations: F, female; M, male; RPR, rapid plasma regain.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cdiv class=\"SimplePara\"\u003eHistological features of the 11 sections\u003c/div\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"11\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eCase\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003ePlasma cells\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eEndothelial swelling\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eInterstitial inflammation\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eIrregular acanthosis\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eElongated rete ridges\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eVacuolar pattern\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eLymphocytes with ample cytoplasm\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003eNeutrophils in stratum corneum\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003eLichenoid pattern\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003eNecrotic keratinocytes\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e1\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e2\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e3\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e4\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e5\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e6\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e7\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e8\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e9\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e10\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e11\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e+\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"11\"\u003ePositive detection (+), Negative detection (-).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cdiv class=\"SimplePara\"\u003eFollow-up results after treatment\u003c/div\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eCase\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eRPR Titer\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eHIV\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eTPPA/TPHA\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eFTA-ABS-IgG\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eFTA-ABS-IgM\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eFollow-up\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003eMonths\u0026para;\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e1\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e0\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eLost\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e2\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e1:8\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eCured\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e4\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e3\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026ge;\u0026thinsp;1:32\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eCured\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e12\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e4\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026ge;\u0026thinsp;1:32\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eCured\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e12\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e5\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026ge;\u0026thinsp;1:32\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eCured\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e9\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e6\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026ge;\u0026thinsp;1:32\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eCured\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e9\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e7\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e1:1\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eLost\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e8\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026ge;\u0026thinsp;1:32\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eCured\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e6\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e9\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e1:8\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eCured\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e6\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e10\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e1:8\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eCured\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e6\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e11\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e0\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eN\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eP\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eCured\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cdiv class=\"SimplePara\"\u003e5\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003e\u0026para; sero-reversion time; N, negative; P, positive\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eEleven biopsies with primary syphilis were included in the histologic analysis. In primary syphilis, plasma cells infiltration [90.9% (10/11)] was the most common pathologic characteristics (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. A). We also noted that necrotic keratinocytes could be observed in 54.5% (6/11) primary syphilis cases (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. C and D). The specimens analyzed by IHC were shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Micro-organisms were discovered in 9 of 10 (90.0%) specimens from cases with primary syphilis and were not detected in the control sections. \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e were seen in all positive patients as typical spiral and thread-like organisms highlighted by red chromogen. The micro-organism is mainly detected in the medium to superficial dermis and the lower epidermis regions (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, A). In the dermis area, the micro-organism was discovered mainly in the perivascular region (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, B). The quantity of the bacteria varied with only a few \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e (sparse, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, C), a moderate amount (moderate) and a large amount (dense, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, D).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e "},{"header":"Discussion","content":" \u003cp\u003eClinically, primary syphilis can present as other ulcerative dermatosis. Histologically, the same applies. In our study, plasma cells infiltration (90.9%) was the most common pattern. It is appear that plasma cells play an important role in the pathophysiology of primary syphilis. Further research could include IHC stain of CD138/38, so as to detect the plasma cells neglected in hematoxylin and eosin staining sections. Necrotic keratinocytes could be detected in 54.5% of primary syphilis patients. Similarly, previous studies also showed that ulcerative lesions covered by necrotic material and cellular debris were most observed in primary syphilis.\u003csup\u003e4\u0026minus;5\u003c/sup\u003e Dilated blood vessels with swelling endothelial cells is generally considered to be a phenomenon of early syphilis.\u003csup\u003e6\u003c/sup\u003e These findings are explained with the IHC findings that \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e was discovered mainly in the perivascular and vascular region in the dermis area. Our study result is in accordance with the previous animal experiment which find \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e localizing to vascular and perivascular regions in all the courses of infection in the infected rabbit testicular tissue samples.\u003csup\u003e7\u003c/sup\u003e According to literature report, \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e is attachment to the endothelial lining of blood vessels, migration of \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e between the junctions of vascular endothelium cells.\u003csup\u003e8,9\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn our study, we have found that the micro-organism is mainly detected in the dermo-epidermal areas in epidermis and lower part of epidermis. In the dermis, the micro-organism was detected mainly in the medium and superficial perivascular region where a notable inflammatory response was in place. Up to now, there is still no reasonable explanation for upper dermal and the epidermal distribution of the micro-organism where it should be killed by our immune system. Previous study showed that early stage syphilitic skin lesions have a characteristic increased T-suppressor lymphocytes acting as closing a innate immune response and causing the persistence of the micro-organism in these lesions.\u003csup\u003e10\u003c/sup\u003e The other possible reason is that the \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e adhesin Tp0751 was previously shown to bind laminin, the most abundant component of the basement membrane,\u003csup\u003e11\u003c/sup\u003e suggesting \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e in host tissue colonization.\u003csup\u003e12\u0026minus;14\u003c/sup\u003e\u003c/p\u003e "},{"header":"Conclusion","content":" \u003cp\u003eThe usual technique for detecting \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e in tissue samples is through Warthin-Starry (silver staining method). Obvious background artifacts are common, as the Warthin-Starry highlights melanin granules also and reticulin fibers causing it difficult to detect the \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e. Our study focused on the evaluation of \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e in primary syphilis by IHC and compared IHC with histologic features. We discovered the presence of \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e in 90.0% of primary syphilitic patients. It is still unknown what proportion of primary syphilis escape this testing method. The capability of \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e escaping our immune system is largely unknown and the distribution of \u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eT. pallidum\u003c/span\u003e in the lesion could bring us some clues to figure out its pathogenesis.\u003c/p\u003e "},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthical Approval and Consent to participate: \u003c/strong\u003eThis study was approved by the institutional review boards of the Peking Union Medical College Hospital (reference number S-K653). All patients consent to participate in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e Written consent for publication have obtained from patients. Informed consent was obtained from all subjects.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u003c/strong\u003e The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests: \u003c/strong\u003eNone reported.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding/Support: \u003c/strong\u003eSupported by Beijing Municipal Science and Technology Commission\u0026nbsp;No. Z191100006619011.We declare that we have no conflicts of interest. We declare that the paper has not been submitted to another journal, and has not been published in whole or in part elsewhere previously.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions:\u003c/strong\u003e Dr Jun Li and Dr He Yi Zheng had full access to all data in the study and take responsibility for the integrity of data and accuracy of data analysis, as well as for the study concept and design. All the authors take responsibility for acquisition, analysis, and interpretation of the data. Ling Leng takes responsibility for drafting of the manuscript. Drs Tao Wang, and Hui Zi Gong take responsibility for critical revision of the manuscript for important intellectual content. Ling Leng was responsible for technical support.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements: \u003c/strong\u003eWe thank the colleagues in the Department of dermatology, Peking Union Medical College Hospital for partially supporting this study and also the general patients included in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors:\u003c/strong\u003e Ling Leng,* Hui Zi Gong*, MD, Tao Wang, MD, He Yi Zheng, MD, Jun Li, MD\u003c/p\u003e\n\u003cp\u003e*co-first authors\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Affiliations:\u003c/strong\u003e Department of Medical Science Research Center (Ling Leng), Department of Dermatology (H Z Gong, T Wang, H Y Zheng, J Li), Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, 100730\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrespondence to:\u003c/strong\u003e Dr Jun Li, Department of Dermatology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. No.1 Shuaifuyuan Wangfujing Dongcheng District, Beijing, China, 100730\u0026nbsp; email address：\u003ca href=\"mailto:[email protected]\"\[email protected]\u003c/a\u003e\u0026nbsp;\u0026nbsp; Telephone number：086-010-69151502\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eYang S, Wu J, Ding C, et al. Epidemiological features of and changes in incidence of infectious diseases in China in the first decade after the SARS outbreak: an observational trend study. Lancet Infect Dis. 2017;17(7):716-725.\u003c/li\u003e\n\u003cli\u003eQuatresooz P, Pi\u0026eacute;rard GE. Skin homing of Treponema pallidum in early syphilis: an immunohistochemical study. Appl Immunohistochem Mol Morphol. 2009;17(1):47-50.\u003c/li\u003e\n\u003cli\u003eBuffet M, Grange PA, Gerhardt P, et al. Diagnosing Treponema pallidum in secondary syphilis by PCR and immunohistochemistry. J Invest Dermatol. 2007;127(10):2345-2350.\u003c/li\u003e\n\u003cli\u003eEngelkens HJ, ten Kate FJ, Vuzevski VD, van der Sluis JJ, Stolz E. Primary and Secondary Syphilis: A Histopathological Study. International Journal of STD \u0026amp; AIDS. 1991; 2: 280-284.\u003c/li\u003e\n\u003cli\u003eMart\u0026iacute;n-Ezquerra G, Fernandez-Casado A, Barco D, Jucgl\u0026agrave; A, Juanpere-Rodero N, Manresa JM. Treponema pallidum distribution patterns in mucocutaneous lesions of primary and secondary syphilis: an immunohistochemical and ultrastructural study. Hum Pathol. 2009; 40: 624-630.\u003c/li\u003e\n\u003cli\u003eSangüenza O, Fleet S, Requena L. Histologic findings of cutaneous infections. Adv Dermatol. 2000;16:361-423.\u003c/li\u003e\n\u003cli\u003eLukehart SA, Baker-Zander SA, Lloyd RM, Sell S. Characterization of lymphocyte responsiveness in early experimental syphilis. II. Nature of cellular infiltration and Treponema pallidum distribution in testicular lesions. J Immunol. 1980;124(1):461-467.\u003c/li\u003e\n\u003cli\u003eFitzgerald TJ, Miller JN, Sykes JA. Treponema pallidum (Nichols strain) in tissue cultures: cellular attachement, entry and survival. Infect Immun. 1975;11(5):1133-1140.\u003c/li\u003e\n\u003cli\u003eThomas DD, Navab M, Haake DA, et al. Treponema pallidum invades intercellular junctions of endothelial cell monolayers. Proc Natl Acad Sci USA.1988;85(10):618-624.\u003c/li\u003e\n\u003cli\u003eEngelkens HJ, ten Kate FJ, Judanarso J, et al. The localisation of treponemes and characterisation of the inflammatory infiltrate in skin biopsies from patients with primary or secondary syphilis, or early infectious yaws. Genitourin Med. 1993;69(2):102-107.\u003c/li\u003e\n\u003cli\u003eBruckner Tuderman L. Biology and pathology of the skin basement membrane zone. Matrix Biol. 1999;18(1):3-4.\u003c/li\u003e\n\u003cli\u003eCameron CE. Identification of a Treponema pallidum laminin-binding protein. Infect Immun. 2003;71(5):2525-2533.\u003c/li\u003e\n\u003cli\u003eCameron CE, Brouwer NL, Tisch LM, Kuroiwa JM. Defining the interaction of the Treponema pallidum adhesin Tp0751 with laminin. Infect Immun. 2005;73(11):7485-7494.\u003c/li\u003e\n\u003cli\u003eCameron CE, Kuroiwa JM, Yamada M, et al. Heterologous expression of the Treponema pallidum laminin-binding adhesin Tp0751 in the culturable spirochete Treponema phagedenis. J Bacteriol. 2008;190(7):2565-2571.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Primary syphilis, Histological features, Immunohistochemistry, Treponema pallidum","lastPublishedDoi":"10.21203/rs.2.24783/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.2.24783/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eBackground:\u003c/em\u003e \u003c/strong\u003eSyphilitic chancre could be misdiagnosed as other skin diseases and a biopsy is sometimes done before serological testing, which makes it essential to find possible primary syphilis patients through histopathology and immunohistochemistry (IHC).\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e\u003cem\u003eMethod:\u003c/em\u003e\u003c/strong\u003e We sought to determine the histopathological and IHC characteristics in primary syphilis. Eleven biopsy specimens were collected from 9 patients diagnosed with primary syphilis. Specimens were analyzed for \u003cem\u003eT. pallidum\u003c/em\u003e using antibody to \u003cem\u003eT. pallidum\u003c/em\u003e. We also compared IHC results with the histological characteristics.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e\u003cem\u003eResults:\u003c/em\u003e \u003c/strong\u003eIn our study, plasma cells infiltration was the most common pattern [90.9% (10/11)] in primary syphilis. Necrotic keratinocytes could be observed in 54.5% (6/11) of primary syphilis. \u003cem\u003eT. pallidum\u003c/em\u003e was discovered in 9 of 10 (90.0%) primary syphilis by IHC. \u003cem\u003eT. pallidum\u003c/em\u003e is mainly detected in the medium to superficial dermis and the lower epidermis regions. In the dermis area, \u003cem\u003eT. pallidum\u003c/em\u003e was discovered mainly around the perivascular regions. \u0026nbsp;\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e\u003cem\u003eConclusion:\u003c/em\u003e \u003c/strong\u003eAlthough serological tests remain the gold standard for the confirming diagnosis of syphilis infection, Histopathological and IHC could be helpful in the diagnosis of some syphilitic patients when serologic testing is not capable of detecting \u003cem\u003eT. pallidum \u003c/em\u003eantibodies in serum. Using IHC technique allows us to precisely find out the location of the microorganism in the syphilitic skin lesions.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","manuscriptTitle":"Primary syphilis: a histological and immunohistochemical evaluation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2020-02-28 00:58:52","doi":"10.21203/rs.2.24783/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8a90c456-be35-4998-928a-0280f9b769d6","owner":[],"postedDate":"February 28th, 2020","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":63517,"name":"Infectious Diseases"}],"tags":[],"updatedAt":"2020-06-04T14:10:13+00:00","versionOfRecord":[],"versionCreatedAt":"2020-02-28 00:58:52","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-15341","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"identity":"rs-15341","version":["v1"]},"buildId":"WrCJVZZCHTDjtuVLN7oU0","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}