{"paper_id":"9b8b388b-4bd0-4f8b-899c-0463f5e2c0cf","body_text":"Luncan et al. BMC Women’s Health          (2022) 22:529  \nhttps://doi.org/10.1186/s12905-022-02128-8\nRESEARCH\n© The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which \npermits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the \noriginal author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or \nother third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line \nto the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory \nregulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this \nlicence, visit http:// creat iveco mmons. org/ licen ses/ by/4. 0/. The Creative Commons Public Domain Dedication waiver (http:// creat iveco \nmmons. org/ publi cdoma in/ zero/1. 0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.\nOpen Access\nThe effectiveness of intrauterine antibiotic \ninfusion versus oral antibiotic therapy \nin the treatment of chronic endometritis \nin patients during IVF (in vitro fertilization) \nprocedures\nMihai Luncan1,2, Anca Huniadi1,2,3*, Erika Bimbo‑Szuhai1,2, Mihai Botea1,2, Ioana Zaha1,3, Liana Stefan1,2,3, \nCorina Beiusanu1, Dana Romanescu1, Annamaria Pallag4, Alin Bodog1, Laurean Ovidiu Pop1 and \nMircea Ioan Șandor1 \nAbstract \nBackground: Chronic Endometritis (CE) is a subtle pathology, likely infectious in most cases, with a negative impact \non the female fertility, but often overlooked even among fertility specialists. The purpose of the study is to demon‑\nstrate the predominant infectious nature of CE and to find the best therapeutic option by comparing the results \nof oral antibiotic therapy versus intrauterine antibiotic infusion in patients with CE undergoing IVF procedures. The \nobjective was to compare the cure rate of CE—defined as the percentage of patients without CE at the test of cure, \nbetween the two groups and, the hysteroscopic aspect with the positive CD 138 staining.\nMethods: This was a prospective, case—control study that took place in a single university fertility clinic, in Oradea, \nRomania and included 57 patients with CE divided into 2 groups: orally administered antibiotics group who received \na combination of antibiotics compared to intrauterine infusion group who received intrauterine infusion of antibiotic. \nChronic Endometritis was diagnosed through hysteroscopy and immunohistochemistry for CD 138. Patients in both \ngroups were tested for CE twice to evaluate the cure rate after oral combination antibiotic therapy versus intrauterine \ninfusion of antibiotic.\nResults: Out of 115 patients with endometrial biopsies 57 tested positive for CE, with a 49.6% chronic endometritis \nprevalence. Among the group that was administered oral antibiotics, 11 patients (45.83%) experienced CE resolution \nafter triple antibiotic therapy. Of the intrauterine infusion group, 25 patients (89.29%) presented negative results (p \n0.0020). The normal hysteroscopic aspect had a similar prevalence in the patients with immunohistochemical positive \nand negative CD 138.\nConclusions: Our study demonstrated the effectiveness and superiority of intrauterine antibiotic infusion over the \nuse of oral combination antibiotic therapy for CE cure.\n*Correspondence:  ancahuniadi@gmail.com\n1 Faculty of Medicine and Pharmacy, University of Oradea, 1St December \nSquare 10, 410073 Oradea, Romania\nFull list of author information is available at the end of the article\n\nPage 2 of 9Luncan et al. BMC Women’s Health          (2022) 22:529 \nTrial Registration: ISRCTN17542620/14.09.2022.\nKeywords: Chronic endometritis, Hysteroscopy, Immunohistochemistry for CD 138, Intrauterine antibiotic infusion, \nOral antibiotic therapy\nIntroduction\nChronic endometritis (CE) is a subtle pathology, prob -\nably infectious in most cases, characterized by an \ninflammatory state of the endometrium caused by vari -\nous pathogens: common gram-positive (Streptococcus, \nStaphylococcus), gram-negative (Escherichia Coli, Kleb -\nsiella pneumoniae, Neisseria gonorrhoeae), intracellular \n(Mycoplasma, Ureaplasma, Chlamydiae) or anaerobic \n(Bifidobacteria, Prevotella) [1]. Chronic endometritis \nusually is asymptomatic or has inconsistent symptoms \nsuch as abnormal bleeding, chronic pelvic pain, dyspare -\nunia or vaginal discharge over a long period of time with \nthe tendency of persistence and slow progression, finally \ncompromising the reproductive potential of patients. \nBecause of these reasons chronic endometritis is rarely \ntaken under consideration even by fertility specialists.\nChronic endometritis is also a diagnostics challenge \n[2]. Hysteroscopy is a useful tool in diagnosing CE, as \nthere are classic images for CE, but its overall accuracy is \noperator dependent. Histology also has some limitations \nand interobserver variability especially because, to date \nthere are no clear recommendations of the criteria for \ndiagnosis of chronic endometritis. The identification of \na pathogen that can cause chronic endometritis in endo -\nmetrial culture is hampered by the exaggerated growth \nof conditional pathogenic microorganisms. Even the \nhistological identification of plasmacyte by hematoxy -\nlin–eosin coloration has its limitations: technically insuf -\nficient coloration, incorrect conservation of probes, and \nstromal proliferative cells with excessive mitosis that can \nmask plasmacytes and lead to a false negative result. On \nthe other hand false-positive results can occur by confus -\ning plasmacytes with mononuclear cells or stromal plas -\nmacytoid cells [3, 4].\nThe markers used in the diagnosis of endometritis are \nMUM1 and Syndecan-1 (or CD 138) [5]. In our study we \nused CD 138. Syndecan-1 (or CD 138) is a transmem -\nbrane heparin proteoglycan on the plasmacyte surface \nand is considered the immunohistochemical marker used \nin the diagnosis of chronic endometritis [6]. In compari -\nson with hysteroscopy alone, the immunohistochemi -\ncal coloration for CD 138 offers a higher specificity and \nsensitivity with minimal variability between different \nobservers [7, 8]. Even though the diagnosis is histological, \nhysteroscopy plays a role in determining the specific site \nof biopsy in chronic endometritis [9]. All being said even \nthe immunohistochemical coloration for CD 138 has its \nlimitations. First of all, the interference of endometrial \nepithelial cells that express CD 138 can be marked by \nmonoclonal antibodies that are specific for CD 138 [10]. \nSecondly, the accuracy of immunohistochemical diag -\nnosis can be influenced by the moment of the endome -\ntrial biopsy in the menstrual cycle and the quantity of \nendometrial tissue that is retrieved. Biopsies retrieved in \nthe proliferative phase of the menstrual cycle have big -\nger chances to detect plasmacytes in comparison with \nthe biopsies taken in the secretory phase of the men -\nstrual cycle [11]. Because of the petechiae characteristics \nof plasmacyte congestion, these can be overlooked in a \nsmall sample [12]. There are variations among diagnos -\ntic criteria between different in vitro fertilization centers \nwhen it comes to chronic endometritis: in some centers \nthe specimens that present with at least 5 positive CD \n138 cells from 1 to 3 of section levels of microtomy are \nconsidered positive, but in many centers only 1 CD 138 \npositive cell in a high power field (HPF) microscope is \nconsidered a criteria for a positive diagnosis [4, 12–14].\nMost likely due to these differences in definition and \npositive diagnosis, the prevalence of this chronic illness \nin women that struggle with infertility is variable: from \n0.2 to 46% [6, 15–17]. In studies that were evaluating \npatients with repeated failure of implantation the per -\ncentage was between 14 and 60% [18–20].\nAt present, there is also a lot of controversies regarding \nthe management of CE: whether to treat or not to treat \nand how to treat. Being an infectious disease, the treat -\nment for chronic endometritis is based on the adminis -\ntration of antibiotics that are effective against the bacteria \nthat is causing this chronic problem. After the adminis -\ntration of antibiotics we expect an improvement of the \ninflammatory changes and endometrial receptivity [20–\n24]. The immune response against bacterial invasion of \nthe uterine cavity during chronic endometritis rarely pro-\ngresses to a systemic inflammatory response [21], there -\nfore the necessity of systemic antibiotic therapy could be \nconsidered but may not be crucial. The local administra -\ntion of antibiotics (uterine infusion) is described in case \nreports [22], as well as a recent clinical study [23].\nMoreover, a new theory about an impaired inflamma -\ntory state of the endometrium relying on multiple patho -\ngenic mechanisms, not only infectious but also hormonal \nand autoimmune could be involved. This would make \nthings even more complicated about this already contro -\nversial pathology [25].\n\nPage 3 of 9\nLuncan et al. BMC Women’s Health          (2022) 22:529 \n \nIn this prospective case control study we aimed find the \nprevalence of CE in infertile patients and to demonstrate \nthe infectious nature of CE and to evaluate the effective -\nness of oral antibiotic therapy compared with local anti -\nbiotic therapy for CE cure.\nMaterial and method\nStudy design\nThis was a prospective, case–control study, conducted at \na single university level fertility center in Oradea, Bihor \ncountry, Romania during the period of time between \n01.01.2021–31.12.2021. This study was conducted \nunder the principles of the Helsinki declaration and has \nbeen approved by the ethics committee of Calla Clinic, \nOradea, Romania (463/05.02.2020). All patients included \nhave signed an informed consent for their participation \nin the study. Information given to patients was about side \neffects of the procedures.\nParticipants\nWe included patients that underwent an IVF proce -\ndure in our clinic and compared women diagnosed with \nCE who received oral antibiotic with women diagnosed \nwith CE who received local antibiotic therapy (infusions) \nreferred to our clinic from 01 January 2021 to 31 Decem -\nber 2021. The patients had the opportunity to choose \nwhether they follow oral or local antibiotic therapy. All \npatients underwent a second biopsy to control the effi -\nciency of the treatment. We included only women with \nhysteroscopy diagnosed CE by immunohistochemistry \nfor CD 138. The diagnosis was based on the demonstra -\ntion > 1 plasma cells per 10 high power fields according to \nmany published studies [5, 26, 27].\nInclusion criteria were: patients that underwent an IVF \nprocedure in our clinic, having various IVF indications \nthat obtained at least two day 5–6 blastocysts and agreed \nwith a hysteroscopic examination.\nExclusion criteria were: acute endometritis or other \nacute pelvic inflammatory disease, placental remanence, \nsteroid and antibiotic treatment within 3  months prior \nto diagnosis, endometrial cancer or atypical hyperplasia \nand refusal of procedure (hysteroscopy) or treatment for \nchronic endometritis.\nThe diagnosis of chronic endometritis is based on a \nhysteroscopy that is done in the beginning of the men -\nstrual cycle (days 9–11). The guided biopsy during \nhysteroscopy was then sent for pathological and immu -\nnohistochemical examination. In this study the positive \ndiagnosis of chronic endometritis is based on the pres -\nence of at least one CD 138 positive plasmacyte per 10 \nhigh power fields [2, 10, 15, 16].\nData collection\nThe data of the patients was gathered in our clinic by two \nauthors. The register included: age of the patient, cause of \ninfertility, previous pregnancies, hysteroscopic findings, \nimmunohistochemical diagnostic, the type of treatment \nthat had been administered the negative immunohisto -\nchemical test after which treatment.\nHysteroscopy and endometrial sampling\nHysteroscopy was done under intravenous general anes -\nthesia, after the disinfection of the perineum with a solu -\ntion of chlorhexidine and the external cervical ostium \nwith iodine solution after a vaginoscopy to minimize \ncontamination risk. Visualization of the uterine mucosa \nwas done by crossing the cervical canal with a compact \nhysteroscope CAMPO TROPHYSCOPE ® (Karl Storz SE \n& Co. KG, Germany), with a HOPKINS ® 30° telescope, \nsize 2.9 mm, length 24 cm, with an irrigation connector \nand an operation sheath with continuous flux 26.152 DA \nand 26.152 DB. Entering the uterine cavity we look for \ntwo tubal ostium and a panoramic image of the uterus. \nWith biopsy forceps we draw a mucosal probe from the \nmacroscopical modified region (polyposis endometrium, \noedema or hyperemia of endometrial mucosa). If there \nare no visible endometrial alterations we extract a biopsy \nwith a catheter (Gynetics Medical Products Endometrial \nCurette) that is crossing under visual control of the cervi-\ncal canal without any contact with the vaginal wall. The \nendometrial probes were put in a saline solution (2 mL) \nand sent to the pathology laboratory for examination.\nHistopathological examination\nEvaluation of endometrial biopsies was performed from \nformalin-fixed paraffin-embedded tissue. Samples were \nsectioned using a Leica RM 2125 RT microtome and pro-\ncessed using the standard hematoxylin and eosin stain \n(HE). Tissue analysis was performed using a standardized \nLeica system for image acquisition and analysis—a DM \n3000 LED microscope equipped with K3 camera.\nTissue specimens were fixed in 10% buffered formalin \n(pH 7.4) for up to 72 h and paraffin-embedded according \nto the standard procedures. A 4  μm representative sec -\ntion from each paraffin-embedded tissue was performed \naccording to a standard automated immunohistochemi -\ncal procedure (Autostainer Link 48 DAKO; Agilent, \nSanta Clara, CA 95.051; United States) [24]. For each \ncase anti-CD138 (cone MI15-DAKO) mouse monoclonal \nantibody, immunohistochemical profile was determined. \nNegative controls were processed by the same methodol -\nogy but omitting the primary antibody. Positive controls \n\nPage 4 of 9Luncan et al. BMC Women’s Health          (2022) 22:529 \nconsisted of normal tonsil positive for CD138. At least 50 \nhigh power fields were examined per specimen and the \nbiopsies were graded as negative for chronic endometritis \nif there was < 1 plasma cells identified per 10 high power \nfields and positive when there was > 1 plasma cells identi-\nfied per 10 high power fields [28].\nAcute endometritis typically represents ascending \ninfection from lower genital tract. The most common \ncauses are  Chlamydia trachomatis,  Neisseria gonor -\nrhoeae, Trichomonas vaginalis and Mycoplasma species.\nThe differential diagnosis can be done by tissue \nexamination. The acute endometritis reveals the pres -\nence of neutrophils infiltrating and destroying endo -\nmetrial epithelium  not plasma cells like in chronic \nendometritis. Sometimes the neutrophils are organized \nin  microabscess. The different inflammatory cells do \nthe diagnostic easily.\nTreatment of chronic endometritis\nThe treatment was decided by the patient after a thor -\nough presentation of the method of administration, dura-\ntion of treatment and side-effects to each patient.\na. Oral antibiotic treatment—to have a high range of \nmicroorganisms that can cause chronic endometritis cov-\nered by the antibiotic we use a combination of 3 antibiot-\nics over a 14 days period of time: ciprofloxacin 500 mg 2 \ntimes a day, doxycycline 100 mg 2 times a day and metro-\nnidazole 500 mg de 2 times a day [25, 29].\nb. Intrauterine antibiotic infusions—our protocol for \nintrauterine infusions includes the administration of 3 ml \nciprofloxacin 200 mg/100 ml concentration every 3 days \nwith 10 infusions in total across a 30 day period of time \nfor each patient. Infusions were done using Labotect \nEmbryo Transfer Catheter 23 cm (Labotect Labor-Tech -\nnik-Gottingen GMBH, Rusdorf, Germany).\nAssessment of CE cure\nIn the follicular phase of the menstrual cycle follow -\ning antibiotic therapy all women underwent a repeat \nendometrial biopsy with CD 138 immunohistochemical \nexamination.\nStatistic analyses\nFor the storage of information from the study and for the \nstatistical analysis we used a medical statistics program \nMedCalc® 12.5.0.0 (MedCalc ® Software, Mariakerke, \nBelgium). Statistical results will be represented by the \nprobability of null (p), a p value under 0.05 underlines a \nsignificant difference between the studied groups. Every \ncontinuous variable will be checked for the value distri -\nbution using the Kolmogorov–Smirnov test. Continuous \nvariables with normal distribution will be represented \nby average and standard deviation in brackets, and the \nasymmetrical distribution by median and interquar -\ntile range in brackets. Also depending on the variable \ncharacter parametric tests will be used (Student test for \nindependent lots) or non-parametric (Mann–Whitney \ntest). Comparison between categorical variables were \ntested using contingency tables and the chi-square test or \nFisher`s test when necessary.\nStudy endpoints\nThe primary endpoint consisted in obtaining the preva -\nlence of CE in a population that undergoes an IVF proce -\ndure. The secondary endpoint was to compare the rate of \nCE resolution between the two groups. The tertiary end -\npoint was to compare the hysteroscopic normal appear -\nance with the presence of chronic endometritis.\nResults\nFrom the total of 232 patients that presented in the given \nperiod of time, 220 remained eligible for treatment, \nfrom which only 115 accepted to do the hysteroscopy \nand the control biopsy. Using the diagnosis criteria 57 \ncases of chronic endometritis were identified. After they \nhave chosen the treatment 27 patients were included in \nthe oral antibiotic therapy group (OAB) and 30 patients \nwere included in the intrauterine antibiotic infusion \ngroup (IAI). Because some patients needed both treat -\nment options to become negative and made part of both \ngroups (the inefficiency of one treatment and changing \nto the other treatment) 5 more patients were excluded \n(3 from the OAB group and 2 from the IAI group). The \nalgorithm of the patient selection is shown in Fig. 1.\nThe demographic characteristics of the study popula -\ntion that underwent an IVF procedure are displayed in \nTable 1. The age, the provenance, the obstetrical history, \nthe normal hysteroscopic aspect were not significantly \ndifferent between groups. Regarding the indication for \nthe IVF procedures, diminished ovarian reserve was \nencountered more frequently in patients without chronic \nendometritis, but we consider this an incidental aspect.\nChronic endometritis prevalence according to the diag-\nnosis criteria is 49.6%. After the diagnosis patients were \ndivided in the oral antibiotic therapy group (OAB) and \nthe intrauterine antibiotic infusion group (IAI). The divi -\nsion of patients according to the treatment option gave us \nthe following results in clinical and demographic charac -\nteristics (Table 2):\nAmong oral antibiotic group, 11 patients (45.83%) \nexperienced CE resolution after the triple antibiotic \ntherapy. Among intrauterine infusion group, 25 patients \n(89.29%) presented negative controls (p 0.0020). The effi -\nciency of the treatment in producing negative CD 138 \ntesting was significantly higher for the patients treated \n\nPage 5 of 9\nLuncan et al. BMC Women’s Health          (2022) 22:529 \n \nby the intrauterine antibiotic infusion: RR = 1.9481 \n(IC95%: 1.2–3.06), p = 0.0039 with NNT = 2.301 (IC95%: \n1.52–4.71).\nThe hysteroscopic aspects of chronic endometritis are \nconsidered to be the classical strawberry pattern but also \nhemorrhagic spots, focal and generalized hyperemia, pale \nFig. 1 Algorithm of patient selection in the study groups\nTable 1 Demographic characteristics of the study population—patients with positive and negative diagnosis for chronic endometritis\nSD = standard deviation; U = urban; R = rural; IVF = in vitro fertilization; Anti mullerian hormone (AMH) = diminished ovarian reserve; PCOS = polycystic ovarian \nsyndrome; FF = feminine factor; MF = masculine factor\nVariable With chronic endometritis\n(n = 57)\nWithout chronic endometritis\n(n = 58)\np\n(statistical \nsignificance)\nAge (years)—average (± SD) 35.08 (± 4.6) 35.84 (± 5.0) 0.4010\nProvenance—U (percentage—%) 38 (66.67%) 36 (62.07%) 0.7490\nPrevious abortion—Yes (percentage—%) 12 (21.05%) 15 (25.86%) 0.6977\nEctopic pregnancy—Yes (percentage—%) 4 (7.01%) 1 (1.72%) 0.3501\nBirth—Yes (percentage—%) 3 (5.26%) 2 (3.45%) 0.9841\nHysteroscopic aspects—normal (percentage—%) 35 (61.40%) 34 (58.62%) 0.9091\nIVF indication (%)\n Low AMH 3 (5.26%) 14 (24.14%) 0.0096\n PCOS 0 (0%) 2 (3.45%) 0.4833\n Tubal 11 (11.29%) 7 (12.07%) 0.4179\nAdvanced maternal\n Age 13 (22.80%) 7 (12.07%) 0.2030\n FF 14 (24.56%) 15 (25.86%) 0.9568\n MF 16 (28.07%) 15 (25.86%) 0.9548\n Unknown 12 (21.05%) 12 (20.69%) 0.8559\n\nPage 6 of 9Luncan et al. BMC Women’s Health          (2022) 22:529 \nand edematous mucosa and the presence of micro-polyps \nas shown in the figure bellow (Fig. 2).\nThe histological evaluation was done by identification \nof one or more plasma cells in the endometrial stroma. \nPresence of CD138 positive plasma cells were confirmed \nby brown colored membranes and cytoplasm [23, 30]. \n(Fig. 3).\nThe normal hysteroscopic aspect had a similar preva -\nlence in patients with the immunohistochemical positive \nCD 138 as in the group that tested negative at the immu -\nnohistochemical CD 138 biopsy for chronic endometritis.\nThe antibiotic treatment had no significant adverse \neffect either orally or in uterine infusion and the hyst -\neroscopic procedure had no complication including no \nbleeding or infections.\nTable 2 Demographic and clinical characteristics for the 2 groups of patients according to the treatment option for chronic \nendometritis\nOAB = oral antibiotic; IAI = Intrauterine antibiotic infusion; SD = standard deviation; U = urban; R = rural; IVF = in vitro fertilization;\nCharacteristics Treatment \nOAB\n(n = 24)\nTreatment \nIAI\n(n = 28)\np\n(statistical \nsemnification)\nAge (years)—average (± DS) 34.92 (± 4.2) 35.14 (± 5.0) 0.8629\nProvenience—U (percentage—%) 14 (58.33%) 19 (67.86%) 0.6729\nAfter treatment—negative (%) 11 (45.83%) 25 (89.29%) 0.0020\nIVF results (%)\n Ongoing pregnancy 5 (20.83%) 13 (46.43%) 0.1007\n Abortion 3 (12.50%) 2 (7.14%) 0.8560\n Birth 1 (4.17%) 0 (0.00%) 0.9379\nFig. 2 Hysteroscopy findings in chronic endometritis. A. Generalized hyperemia. B. Pale mucosa with polyp. C. Pale mucosa with hemorrhagic \nspots. D. Strawberry aspect. E. Focal hyperemia. F. Micro‑polyps\n\nPage 7 of 9\nLuncan et al. BMC Women’s Health          (2022) 22:529 \n \nDiscussions\nOur study provides new and clinical relevant information \nfor physicians about the management of chronic endo -\nmetritis that remains an emerging topic regarding its \ndiagnosis, treatment and its impact on the result of fertil -\nity treatments, as much as, frequently the microbiological \nresults of vaginal and uterine environment are negative \n[31].\nThe hysteroscopic examination as a diagnostic tool \nis used by many practitioners [32, 33], but as our study \nshows the endometrium hysteroscopic view is a vague \ndiagnosis criteria [34], the normal hysteroscopic aspect \ndid not differ significantly between the positive CD 138 \nand negative CD 138 groups. This finding proves the \nimportance of endometrial biopsy testing in all patients, \neven if the hysteroscopic view appears normal.\nAlthough there is no unanimously accepted defini -\ntion of CE, pathologists agree that using IHC to deter -\nmine plasma cells by labeling CD138 is currently the \nmost specific and reliable method. Improvement of \nthe diagnosis rate in CE is achieved by implementation \nof IHC techniques [35]. Besides the true plasmacytes, \nthere are also cells with a plasmacytoid appearance \n(mononuclear and plasmacytoid stromal cells) which in \ncase of using basic HE stain can be confused with the \nplasma cells. Additional IHC techniques decrease the \nfalse-positive rate, which leads to less overtreatment \nin women [6 ]. All published studies show that immu -\nnohistochemistry for CD138 positive cells is a golden \nstandard in CE [20]. Although there is no consensus on \nthe IHC assessment of plasma cells, the vast majority \nof authors believe that the presence of a single cell is \nsufficient for the diagnosis of CE. Other interpretations \nused to evaluate CD138 are related to the variable num -\nber of plasma cells or the number of HPF images taken \ninto account, from one plasma cell on HPF to 5 plasma \ncells on 10 HPF or from at least one plasma cell on 10 \nHPF to 5 plasma cells on 20 HPF [18, 20, 21, 36].\nFig. 3 a. Fragment of the endometrial mucosa showing proliferative endometrial glands with an edematous stroma. It is difficult to identify plasma \ncells in HE staining. Most inflammatory cells are lymphocytes (HE 100X). b. Fragment of the endometrial mucosa that shows a positive reaction to \nCD138 by the IHC (immunohistochemical) technique. Positive control is represented by glandular epithelial cells. In the stroma there are cells with \na positive expression (100x). c. The image shows the expression of the positive control (glands) for the CD138 reaction and in the stroma there are \nseveral cells with surface marker expression, with equal epithelial intensity of CD138 (plasma cells). Most stromal cells are negative. 200X\n\nPage 8 of 9Luncan et al. BMC Women’s Health          (2022) 22:529 \nHowever, the use of HPF-related assessment is \nrestrictive and arbitrary in some ways. In the case of \nsmall biopsies, the HPF report may lead to false-nega -\ntive results. Inclusion of only 10 HPFs may not be suf -\nficient to produce a consistently reproducible result, \nbecause in most cases the number of plasma cells pre -\nsent in the endometrial stroma is low. From the histo -\nlogical point of view, the most accepted definition of \nCE is the presence of a single cell labelled CD138 in the \nentire surface of the sample [27, 35] and we agree with \nthis hypothesis.\nPrevalence in our study was 49.6% but we took into \nconsideration an infertile population requiring an IVF \nprocedure and we used strict diagnostic criteria. Other \nauthors have also published high prevalence values \nregarding specific groups: from 9 to 56% in recurrent \nmiscarriage [15, 20, 37] and from 14 to 57.3% in patients \nwith recurrent implantation failure [12, 21, 35].\nThe main of observation criteria is the negative immu -\nnohistochemical field after different treatment options: \noral antibiotic administration and intrauterine infu -\nsion. To our knowledge there are two publications that \ndescribe the method of intrauterine antibiotic infusion: a \ncase report [22] that observes the disappearance of clini -\ncal and paraclinical findings in chronic endometritis after \nintrauterine antibiotic infusions in patients that did not \nrespond by oral antibiotics and a randomized trial [38] \nthat compares the oral antibiotic therapy and the simulta-\nneous oral antibiotic therapy with intrauterine antibiotic \ninfusion. Similarly to the previously mentioned studies, \nour research shows better results in attaining a negative \nCD138 immunohistochemical finding after the intrauter-\nine antibiotic infusion as a treatment option when com -\npared to oral antibiotic treatment.\nStudy limitations\nBeing a unicentric prospective study with strict inclu -\nsion criteria and the necessity of a positive diagnosis of \nchronic endometritis, the number of cases will be lim -\nited, which will lower the statistical power of conclu -\nsions. The treatment with antibiotic in uterine infusions \nis recent in practice and we have considered that the \nacceptance of patients is mandatory, which excludes the \npossibility of randomization leading to inequal groups \nand error sources.\nConclusion\nBased on our findings there is a high prevalence of \nchronic endometritis in infertile patients and screen -\ning for it is useful and should be implemented. In the \nvast majority of the cases we obtained negative results \nafter antibiotic treatment. This is an argument for the \ninfectious nature of chronic endometritis. Antibiotic \ntreatment administered through intrauterine infusions \nis much better than oral antibiotic treatment for cur -\ning chronic endometritis. Accordingly future studies on \nchronic endometritis therapy involving untreated con -\ntrol are probably discouraged for ethical reasons.\nAcknowledgements\nNot applicable\nAuthor contributions\nAll authors read and approved the final manuscript. All authors have equal \ncontribution to this manuscript.\nFunding\nOrganisation: CALLA Infertility Center. CA Rosetti Street, No 1OradeaRoma‑\nnia410103. + 40359404404. calla@ginecologie.ro. Type: Hospital/treatment \ncenter. Website: www. calla. ro. Privacy: Public.\nAvailability of data and materials\nThe datasets used and/or analysed during the current study available from the \ncorresponding author on reasonable request.\nDeclarations\nEthics approval and consent to participate\nThis study was conducted under the principles of the Helsinki declaration and \nhas been approved by the ethics committee of Calla Clinic, Oradea, Romania \n(463/05.02.2020). All patients included have signed an informed consent for \ntheir participation in the study. Information given to patients was about side \neffects of the procedures.\nConsent for publication\nNot applicable.\nCompeting interests\nNot applicable.\nAuthor details\n1 Faculty of Medicine and Pharmacy, University of Oradea, 1St December \nSquare 10, 410073 Oradea, Romania. 2 Pelican Clinical Hospital, Corneliu \nCoposu Street, 2, 41045Ö, Oradea, Romania. 3 Calla‑Infertility Diagnostic \nand Treatment Center, Constantin A. Rosetti Street, 410103 Oradea, Romania. \n4 Department of Pharmacy, Faculty of Medicine and Pharmacy, University \nof Oradea, 29 Nicolae Jiga Street, 410028 Oradea, Romania. \nReceived: 16 September 2022   Accepted: 14 December 2022\nReferences\n 1. Moreno I, Cicinelli E, Garcia‑ Grau I, Gonzalez‑Monfort M, Bau D, Vilella \nF, et al. The diagnosis of chronic endometritis in infertile asympto ‑\nmatic women: a comparative study of histology, microbial cultures, \nhysteroscopy, and molecular microbiology. Am J Obstet Gynecol. \n2018;218:602e1‑616. https:// doi. org/ 10. 1016/j. ajog. 2018. 02. 012.\n 2. Kasius C, Fatemi H, Bourgain C, Sie GD, Eijkemans R, et al. The impact \nof chronic endometritis on reproductive outcome. Fertil Steril. \n2011;96(6):1451–5. https:// doi. org/ 10. 1016/j. fertn stert. 2011. 09. 039.\n 3. Garner IBB, Nickell JA, Korourian S. Routine syndecan‑1 immunohisto‑\nchemistry aids in the diagnosis of chronic endometritis. 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Mod Pathol. 2010;23:1136–46. https:// doi. org/ 10. \n1038/ modpa thol. 2010. 98.\n 37. Mcqueen DB, Perfetto CO, Hazard FK, Lathi RB. Pregnancy outcomes in \nwomen with chronic endometritis and recurrent pregnancy loss. Fertil \nSteril. 2015;104:927–31. https:// doi. org/ 10. 1016/j. fertn stert. 2015. 06. 044.\n 38. Pantos K, Simopoulou M, Maziotis E, Rapani A, Grigoriadis S, Tsioulou P , \nGiannelou P , Nitsos N, Tzonis P , Koutsilieris M, Sfakianoudis K. Introducing \nintrauterine antibiotic infusion as a novel approach in effectively treating \nchronic endometritis and restoring reproductive dynamics: a rand‑\nomized pilot study. Sci Rep. 2021;11(1):15581. https:// doi. org/ 10. 1038/ \ns41598‑ 021‑ 95072‑w.\nPublisher’s Note\nSpringer Nature remains neutral with regard to jurisdictional claims in pub‑\nlished maps and institutional affiliations.","source_license":"CC0","license_restricted":false}