Clinical Evaluation of an Alternaria alternata Extract Used for Skin Prick Test in Diagnosing

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Data may be preliminary. 9 January 2026 V1 Latest version Share on Clinical Evaluation of an Alternaria alternata Extract Used for Skin Prick Test in Diagnosing Authors : XIN LI 0009-0003-5749-6326 , Jian-Qing Gu , Ruiqi Wang , Lianglu Wang , Hong Li , Jin-Lu Sun 0000-0002-9991-4245 , Yu Xiang Zhi 0000-0001-7539-6650 , … Show All … , Kai Guan 0000-0003-0850-5874 , Liping Wen , Zixi Wang , Lisha Li , Rui Tang 0000-0001-5889-3858 , Le Cui , Ying-Yang Xu 0000-0002-0583-1925 , Tao Xu , and Jia Yin 0000-0002-7858-4259 [email protected] Show Fewer Authors Info & Affiliations https://doi.org/10.22541/au.176796196.61797750/v1 205 views 65 downloads Contents Abstract Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract \articletype Original Articles Background: Alternaria alternata is a major fungal allergen, yet standardized skin prick test (SPT) extracts are lacking in China, hindering the use of this simple, first-line diagnostic tool. This study aimed to clinically evaluate a novel, domestically developed A. alternata extract for SPT and establish a diagnostic cutoff in a Chinese population. Methods: In this prospective, single-center study, 910 patients with allergic diseases were consecutively enrolled. All underwent SPT with the in-house A. alternata extract (Alt a 1: 25.7–34.8 µg/mL). Serum-specific IgE (sIgE) (ImmunoCAP™) served as the reference standard. Diagnostic accuracy was analyzed using receiver operating characteristic (ROC) curves. Safety was assessed by monitoring adverse events. Results: The per-protocol set included 610 subjects. The area under the ROC curve was 0.868 (95% CI: 0.839–0.897). The optimal diagnostic cutoff was a mean wheal diameter of 3.25 mm, yielding a sensitivity of 79.32% (95% CI: 74.46%–84.18%) and specificity of 86.11% (95% CI: 82.35%–89.87%). To achieve 95% specificity, the cutoff increased to 4.25 mm. No adverse events were reported among all 910 participants. Conclusion: The novel A. alternata SPT extract demonstrates high diagnostic accuracy and an excellent safety profile. The established cutoff of 3.25 mm provides a population-optimized threshold for clinical diagnosis in China. This study addresses a critical gap in allergen standardization and supports the adoption of SPT as a reliable, first-line diagnostic tool for fungal allergy in clinical practice. \articletype Original Articles Clinical Evaluation of an Alternaria alternata Extract Used for Skin Prick Test in Diagnosing Xin Li 1 , Jianqing Gu 1 , Ruiqi Wang 1 , Lianglu Wang 1 , Hong Li 1 , Jinlyu Sun 1 , Yuxiang Zhi 1 ,Kai Guan 1 , Liping Wen 1 , Zixi Wang 1 , Lisha Li 1 , Rui Tang 1 , Le Cui 1 ,Yingyang Xu 1 , Tao Xu 2 , Jia Yin 1 1 Department of Allergy, Beijing Key Laboratory of Precision Medicine for Diagnosis and Treatment of Allergic Diseases, National Clinical Research Center for Dermatologic and Immunologic Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100730, China 2 Department of Statistics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100730, China \articletype Original Articles Abstract Background: Alternaria alternata is a major fungal allergen, yet standardized skin prick test (SPT) extracts are lacking in China, hindering the use of this simple, first-line diagnostic tool. This study aimed to clinically evaluate a novel, domestically developed A. alternata extract for SPT and establish a diagnostic cutoff in a Chinese population. Methods: In this prospective, single-center study, 910 patients with allergic diseases were consecutively enrolled. All underwent SPT with the in-house A. alternata extract (Alt a 1: 25.7–34.8 µg/mL). Serum-specific IgE (sIgE) (ImmunoCAP™) served as the reference standard. Diagnostic accuracy was analyzed using receiver operating characteristic (ROC) curves. Safety was assessed by monitoring adverse events. Results: The per-protocol set included 610 subjects. The area under the ROC curve was 0.868 (95% CI: 0.839–0.897). The optimal diagnostic cutoff was a mean wheal diameter of 3.25 mm, yielding a sensitivity of 79.32% (95% CI: 74.46%–84.18%) and specificity of 86.11% (95% CI: 82.35%–89.87%). To achieve 95% specificity, the cutoff increased to 4.25 mm. No adverse events were reported among all 910 participants. Conclusion: The novel A. alternata SPT extract demonstrates high diagnostic accuracy and an excellent safety profile. The established cutoff of 3.25 mm provides a population-optimized threshold for clinical diagnosis in China. This study addresses a critical gap in allergen standardization and supports the adoption of SPT as a reliable, first-line diagnostic tool for fungal allergy in clinical practice. Alternaria alternata represents one of the most ubiquitous and clinically relevant airborne fungal allergens, commonly encountered in decomposing vegetation, soil, and ambient air [1]. Sporulation exhibits distinct seasonal periodicity, with peak levels occurring during warm and humid summer and autumn months [2]; however, indoor environments such as air‑conditioning systems and damp building materials can sustain perennial exposure [3][4][5][6]. Under specific environmental conditions—notably during thunderstorms or agricultural activities—spore concentrations may escalate to several tens of thousands per cubic meter. Fragmented Alternaria spores have been implicated as a likely trigger of “thunderstorm asthma” epidemics [7]. These findings align with reports on the high prevalence of mold-related allergic diseases in China [8][9]. The estimated prevalence of fungal sensitization in the general population ranges from 3% to 10%, whereas rates among atopic individuals and asthma patients rise substantially, reaching up to 44% and 80%, respectively, for sensitization to at least one fungal species [10-17,26]. Data from the U.S. National Health and Nutrition Examination Survey (NHANES) corroborate these figures, reporting a 12.9% sensitization rate to A. alternata in the general U.S. population [6]. Further evidence from a multicenter study conducted by the Global Allergy and Asthma European Network (GA²LEN), encompassing over 3000 allergy patients across 14 European countries, demonstrated a mean sensitization rate of 8.9% to A. alternata , with marked geographical heterogeneity—ranging from 0.8% in London, UK, to 23% in Athens, Greece [16]. Similarly, a Polish study involving nearly 500 allergic adults identified Alternaria as the most frequent causative allergen, accounting for 47.1% of symptomatic cases [18]. Evidence from China aligns with these international patterns. In Chongqing, the overall sensitization rate to common airborne fungi was 9.80% (377/3845), of which Alternaria accounted for 22.81% of all fungal-related sensitization cases [19]. Regional studies conducted in Zhenjiang, Ezhou, Binzhou, Zibo, and Shiyang consistently identified Alternaria as a predominant fungal allergen strongly associated with allergic rhinitis and asthma [20-24], findings that are concordant with reports from the United States [25]. Moreover, multiple studies highlight a notable upward trend in fungal sensitization rates globally [16,17,26-28]. Skin testing—comprising percutaneous (prick/puncture) and intracutaneous (intradermal) methods [29]—remains a cornerstone in the diagnostic work‑up of IgE‑mediated conditions such as allergic rhinitis, asthma, and anaphylaxis, used alongside detailed clinical history and physical examination. The skin prick test (SPT) is particularly favoured for its simplicity, reproducibility, favourable safety profile, and cost‑effectiveness, and is recommended by the European Academy of Allergy and Clinical Immunology (EAACI) as a first‑line diagnostic tool for allergic diseases. Despite these advantages, the clinical application of SPT for mould allergens in China remains limited, largely owing to the scarcity of standardized allergen extracts and a paucity of large‑scale clinical validation studies [30]. The present study, therefore, aimed to evaluate the diagnostic performance and safety of an A. alternata extract for SPT in clinical practice, using allergen‑specific immunoglobulin E (sIgE) as the reference standard, and to establish a clinically relevant diagnostic cutoff value. Materials and Methods \articletype Original Articles Study Design and Participants This prospective, single-center, cross-sectional study consecutively enrolled patients with physician-diagnosed allergic diseases (allergic rhinitis, asthma, atopic dermatitis, or allergic conjunctivitis) from the Allergy Department of Peking Union Medical College Hospital (PUMCH) between August 10, 2015, and August 30, 2017. The study protocol was approved by the Institutional Ethics Committee of PUMCH (Approval No. JS‑858). Written informed consent was obtained from all participants or their legal guardians. Inclusion and Exclusion Criteria Eligible subjects were aged 4–70 years and had a documented history of A. alternata intradermal testing (IDT) or specific IgE detection. Exclusion criteria comprised: (1) failure to discontinue antihistamines for ≥5 half‑lives before testing; (2) use of systemic corticosteroids; (3) positive dermatographism; (4) local skin pathology (infection, inflammation, trauma or scarring) at test sites; (5) psoriasis; (6) acute exacerbation of allergic disease; (7) severe systemic illness; (8) current β‑blocker therapy; (9) pregnancy; or (10) any other condition deemed by investigators to potentially affect trial safety or data integrity. Study Procedures and Assessments Allergen Extract and Skin Prick Test The A. alternata SPT extract was prepared in-house, comprising water-soluble active protein of A.alternata allergen in a phosphate-buffered solution containing 50% glycerol (1 mL/bottle). The major allergen Alt a 1 content was quantified using an ELISA kit based on mAb to Alt a 1 (Indoor Biotechnologies, Charlottesville, VA, USA)). Total protein content was measured using the Bradford assay (Solarbio, Beijing, China) with bovine serum albumin as the standard. All enrolled participants underwent standardized SPT on the volar forearm (2–3 cm distal to the wrist and antecubital fossa) following European guidelines [31]. Disposable prick lancets (Huaian Lanxing Plastic Instrument Co., Ltd.), validated in earlier studies [32], were used. A negative control (allergen-free buffer-glycerol) and a positive control (histamine dihydrochloride) were included in each test series. After skin disinfection, allergen extracts and controls were applied at 2 cm intervals and pricked. Wheal reactions were measured after 15 min. The mean wheal diameter (MWD) was calculated as (D + d)/2, where D and d represent the longest and perpendicular diameters. A. alternata sIgE levels, adverse events, and participant compliance were documented concurrently. All assessments were performed by evaluators blinded to clinical information and sIgE results. \articletype Original Articles sIgE Measurement Serum sIgE levels were analyzed using the ImmunoCAP™ system on Phadia 1000 Immunoassay Analyzer (Thermo Fisher Scientific, MA, USA). A level ≥0.35 kUA/L was considered positive. Adverse Event Monitoring Participants were monitored for local (pruritus, erythema, persistent swelling, induration) and systemic adverse events through direct observation at 15 minutes and 1 hour post-SPT, followed by telephone interviews at 6, 12, and 24 hours. Any medication use was documented. The study process, followed previous study, is presented in Table 1 [32] . Table 1. Research process. \articletype Original Articles Estimation Content Screening Follow-up 1 (same day) Follow-up 2 (the next day) Medical history × Intradermal test or sIgE results × Informed consent × Prick results × Prick result record × Alternaria alternata sIgE × Adverse event records × ∗ × † Compliance evaluation × × \articletype Original Articles ∗ Adverse events occurring on the same day as the SPT, 15 min and 1 h after pricking. † Adverse events occurring on the day after the SPT and 6 h after pricking. × This symbol indicates that the row step was finished at the column time. Statistical Analysis Diagnostic performance was evaluated using the Youden index (sensitivity + specificity − 1). For a conventional cut‑off of ≥3 mm, subjects were classified as follows: True‑positive (tp): sIgE ≥ 0.35 kU/L and positive SPT; True‑negative (tn): sIgE < 0.35 kU/L and negative SPT; False‑positive (fp): sIgE < 0.35 kU/L but positive SPT; False‑negative (fn): sIgE ≥ 0.35 kU/L but negative SPT. Sensitivity [tp/(tp + fn)], specificity [tn/(tn + fp)], positive predictive value [PPV = tp/(tp + fp)], negative predictive value [NPV = tn/(tn + fn)] and overall test efficiency [(tp + tn)/(tp + fp + tn + fn)] were calculated. Receiver operating characteristic (ROC) curve analysis was performed with serum Alternaria alternata ‑sIgE as the reference standard to determine sensitivity and specificity across varying SPT cut‑off values. All analyses were conducted using SPSS® software (version 26.0). Sample‑size estimation The required sample size was estimated using the formula:\(n=\frac{Z_{1-\alpha/2}^{2}P(1-P)}{\Delta^{2}}\), where \(Z_{1-\alpha/2}^{2}\)denotes the quantile of the standard normal distribution, P the anticipated sensitivity or specificity, and Δ the permissible error margin for \(P\). With\(\Delta\) = 0.05 and \(\alpha\) = 0.05 (two‑tailed), \(Z_{1-\alpha/2}^{2}\)=1.96. Based on performance data from comparable commercial products, an expected sensitivity of 70.0% required at least 323 subjects in the positive cohort, whereas an expected specificity of 90.0% required at least 139 subjects in the negative cohort. Result Study population A total of 910 subjects were enrolled and completed the study without any dropouts. The full analysis set (FAS) comprised 757 participants, while 153 subjects were excluded due to unavailable sIgE results. After further exclusion of 147 subjects who did not meet the predefined data‑exclusion criteria—including failure to meet inclusion/exclusion criteria, missing sIgE or SPT data, an MWD <3 mm for the positive control, or an MWD ≥3 mm for the negative control—610 individuals constituted the per‑protocol set (PPS). The safety set (SS) included all 910 enrolled subjects. Baseline characteristics of the FAS and PPS are summarized in Table 2. In the FAS, the mean age was 23.06 ± 14.27 years (range 4–65 years), with 438 males (57.86%) and 319 females (42.14%). In the PPS, the mean age was 22.00 ± 14.14 years (range 4–65 years), consisting of 368 males (60.33%) and 242 females (39.67%). Concomitant allergy and asthma medications are detailed in Table 2. Table 2. Baseline subject characteristics. \articletype Original Articles FAS PPS SS Number of subjects, n 757 610 910 Gender Male, n ( %) 438(57.86%) 368( 60.33%) 515(59.59%) Female, n ( %) 319(42.14%) 242( 39.67%) 395(43.41%) Age, mean ± SD 23.06 ± 14.27 22 ± 14.14 24.32 ± 14.53 Median 18.10 16.06 20.28 Q1; Q3 11.10; 33.22 10.61;31.46 11.66; 34.29 MIN; MAX 4.59; 64.45 4.59; 64.45 4.59; 65.84 Allergy medication, n Antihistamine 2 1 4 LTRA 2 2 3 Mast cell stabiliser 0 0 0 INCS 1 1 2 Asthma medication, n SABA 0 0 0 ICS 0 0 0 ICS+LABA 0 0 1 \articletype Original Articles Allergen content Three independent assays of the Alternaria alternata prick solution (PUMCH) yielded Alt a 1 concentrations ranging from 25.7 to 34.8 μg/mL. Diagnostic accuracy Receiver operating characteristic analysis using serum A. alternata sIgE as the reference standard showed an area under the curve (AUC) of 84.55% (95% CI: 81.77–87.34%) in the FAS. Performance improved in the PPS, with an AUC of 86.79% (95% CI: 83.87–89.72%) (Figure 1). Within the PPS, the optimal cut‑off for skin prick test was a MWD of 3.25 mm, corresponding to a sensitivity of 81.10% (95% CI: 76.76–85.24%) and specificity of 79.32% (95% CI: 74.46–84.18%). Case distributions at MWD thresholds of 3.00 mm, 3.25 mm, and 4.25 mm are presented in Table 3. Detailed diagnostic performance metrics—including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratio, accuracy, and F1 score—for each cut‑off are provided in Table 4. To achieve 95% specificity, the cut‑off increased to 4.25 mm. Table 3. Case distribution allergen extracts of Alternaria alternata used for SPTs in the diagnosis of Alternaria alternata allergy (case distribution of PPS). MWD sIgE SPT Positive Negative Total 3.00mm Positive 305 39 344 Negative 82 184 266 Total 387 223 610 3.25mm Positive 279 65 344 Negative 45 211 266 Total 324 286 610 4.25mm Positive 178 166 344 Negative 18 248 266 Total 196 414 610 \articletype Original Articles Table 4. Accuracy outcomes of allergen extracts of Alternaria alternata used for SPTs in the diagnosis of Alternaria alternata allergy (PPS) \articletype Original Articles MWD Index F1 score (%) Accuracy/Concordance rate (%) Sensitivity/Recall (%) Specificity (%) Positive predictive value/Precision Negative predictive value Positive likelihood ratio Negative likelihood ratio 3.00mm Estimated value 83.45 80.16 88.66 69.17 78.81 82.51 2.88 0.164 Standard error 15.05 1.61 1.71 3.10 2.08 2.55 0.25 0.179 Lower limit of 95% CI 80.50 77.00 85.31 63.10 74.73 77.51 2.41 -0.186 Upper limit of 95% CI 86.40 83.32 92.01 75.24 82.89 87.51 3.44 0.514 3.25mm Estimated value 83.53 80.33 81.10 79.32 86.11 73.78 3.92 0.238 Standard error 1.502 1.61 2.11 2.48 1.92 2.60 0.123 0.145 Lower limit of 95% CI 80.59 77.17 76.96 74.46 82.35 68.68 3.08 -0.046 Upper limit of 95% CI 86.48 83.49 85.24 84.18 89.87 78.88 4.99 0.522 4.25mm Estimated value 65.93 69.84 51.74 93.23 90.82 59.90 7.65 0.518 Standard error 1.919 1.858 2.96 1.54 2.06 2.41 0.0546 0.104 Lower limit of 95% CI 62.17 66.19 46.46 90.21 86.77 55.18 6.87 0.313 Upper limit of 95% CI 69.69 73.48 57.02 96.25 94.86 64.63 8.50 0.722 Note: F1 score: 2× (precision×recall)/(precision+recall), accuracy: (tp + tn)/(tp+fp+fn+tn), sensitivity: tp/(tp+fn), specificity: tn/(fp+tn), positive predictive value: tp/(tp+fp), negative predictive value: tn/(tn+fn), . Subgroup analyses Diagnostic performance varied across age groups (Table 5). In participants aged 4–18 years, the F1 score reached 87.79% with an accuracy of 82.07%. The 18–45 year group showed a sensitivity of 86.96% and specificity of 80.92%. However, in the 45–65 year group, sensitivity declined to 37.50%, whereas specificity remained high at 84.62%. In contrast, no marked differences in diagnostic accuracy were observed between male and female participants. Safety No unexpected or serious adverse events were reported among the 910 subjects in the safety set. Table 5. Accuracy outcomes of allergen extracts of Alternaria alternata used for SPTs in the diagnosis of Alternaria alternata allergy in different age groups and ganders (PPS) \articletype Original Articles Catagergy F1 score(%) Accuracy/Concordance rate(%) Sensitivity(%) Specificity(%) Positive predictive value Negative predictive value Likelihood ratio Age groups (years) ≥4 and <18 87.79 82.07 80.90 87.10 96.43 51.43 6.26 ≥18 and <45 75.95 82.81 86.96 80.92 67.42 93.18 4.56 ≥45 and <65 31.58 78.33 37.50 84.62 27.27 89.80 2.44 Ganders Male 85.66 80.98 81.96 78.76 89.70 65.93 3.86 Female 77.78 83.47 78.65 86.27 76.92 87.42 5.73 \articletype Original Articles Discussion This investigator-initiated prospective study systematically evaluated a domestically developed Alternaria alternata skin prick test extract in a large Chinese cohort. The findings demonstrated favorable diagnostic accuracy alongside an excellent safety profile among participants. Receiver operating characteristic analysis identified 3.25 mm as the optimal mean wheal diameter cutoff for clinical diagnosis, a notable deviation from the conventional 3 mm threshold. The diagnostic accuracy observed in this study aligns with global standards for fungal allergen testing. The area under the curve reached 86.79% in the PPS, reflecting strong concordance between SPT results and serum Alternaria sIgE levels. Notably, the sensitivity varied across age groups, declining to 37.50% in individuals aged 45–65 years. This age‑related decrease is consistent with previous reports of diminished skin reactivity in older adults [42], highlighting the importance of age‑stratified interpretation of SPT results in clinical practice. The establishment of a 3.25 mm cutoff represents a meaningful adjustment to the widely adopted 3 mm standard. This finding is particularly relevant in the Chinese population, where skin sensitivity patterns may differ from those in Western cohorts. The higher cutoff may reduce false‑positive rates while maintaining clinically adequate sensitivity, thereby improving the reliability of SPT in diagnosing Alternaria allergy. The development of this domestic extract addresses an urgent need for cost‑effective, locally produced prick‑test reagents in China. Skin testing, first described by Blackley in 1867, has evolved into a reliable and economical technique for diagnosing IgE‑mediated allergic diseases [31]. Although IDT has been used in China for many years, current guidelines recommend it as a sequential diagnostic step after SPT [33]. This recommendation is supported by evidence showing that while IDT offers superior sensitivity, it exhibits significantly lower specificity than SPT. Moreover, its technical complexity and challenges in dose standardization elevate the risk of false‑positive reactions [29,34]. The present single‑center cross‑sectional study confirmed that Alternaria allergy predominantly affects children (329/610, 53.93%). As a less painful procedure, SPT demonstrated higher clinical acceptability than IDT. Despite its global adoption for in vivo allergen detection [35,36], SPT remains underutilized in China, largely due to the scarcity of affordable, locally developed allergen extracts. From a methodological perspective, Alternaria ‑specific IgE testing served as the reference standard based on two established principles: the Thermo Fisher ImmunoCAP system has shown superior reproducibility and well‑documented clinical correlation for serum sIgE quantification [37,38], and multiple studies have confirmed substantial agreement between serum sIgE levels and SPT outcomes [35,39,40], supporting its use as a reliable in vitro diagnostic reference. Although provocation testing remains the diagnostic paradigm for allergic diseases, limited standardization of protocols in China and safety concerns regarding severe reactions necessitated the use of ImmunoCAP‑based sIgE assessment for SPT validation. Comprehensive quality‑control measures were implemented throughout all SPT procedures. Variables known to influence test accuracy—including skin reactivity [41], age‑dependent response variation [42], medication interference [43], needle material properties [44], and application technique [45]—were controlled. Patients with dermatographic urticaria were excluded via preliminary scratch testing, and simultaneous positive (histamine) and negative (saline) controls were included in each test series. All participants underwent an antihistamine washout period exceeding five half‑lives, and standardized chip‑prick lancets—the only medically certified devices available domestically—were uniformly employed. Questionable results were systematically excluded using predefined data‑filtering criteria to minimize technical variability. Future standardization may benefit from automated application systems that eliminate operator‑dependent technique variations [46]. Significant variations in allergen content have been reported among different A. alternata SPT solutions, depending on fungal subspecies and manufacturing processes, with concentrations ranging from used in this study contained a minimum Alt a 1 concentration of 25.7 μg/mL, placing it in the moderate‑to‑high range relative to existing commercial preparations. Previous research established that 3.7 μg/mL Alt a 1 represents the diagnostic threshold required to elicit cutaneous reactions equivalent to 1% histamine dihydrochloride [52]. Compared with internationally available products, the domestic extract demonstrated comparable major allergen content and achieved a sensitivity of 79.32% and specificity of 86.11% in a large cohort (n=910), providing robust evidence for domestic allergen standardization. Table 6. Main allergen protein concentrations of major Alternaria alternata allergen extracts on the market. \articletype Original Articles Author-year Country Manufacturer Alt a 1 (μg/mL) This study China PUMCH 30.25 Thomas J. Grier et al (2016) [50] The United States of America Greer (1:10wt/vol Aqueous) 20.9-34.3 Greer (1:20wt/vol Glycerinated) 9.8-17.0 S. Kespohl et al (2016) [47] Germany Allergopharma 124 ALK/Abelló 79 HAL 8 Lofarma 2 S. Kespohl et al (2013) [48] Germany ALK/Abelló 101 Allergopharma 27 Bencard 3 Lofarma 1 HAL 5 Stallergen 4 Allerbio 0.2 Robert E.Esch (2004) [49] The United States of America Greer 1.85 Hollister-Stier 2.75 ALK-Abello 0.04 Allergy Labs 0.05 Allermed 0.05 Nelco Labs 2.04 Antigen Labs 0.09 Lisa Vailes et al (2001) [51] The United States of America, Germany, Austria Meridian (ALK/Abelló) 0.03 0.01 Nelco 1.93 0.57 Bayer 6.09 3.72 Center 0.50 0.38 Greer 1.00 0.73 Allermed 1.57 1.35 Allergy Labs,Ohio 2.23 0.95 Allergy Labs,Okla ＜0.01 0.04 \articletype Original Articles Regarding safety, SPTs can potentially induce local or systemic adverse reactions, including rare instances of anaphylactic shock. However, no local or systemic adverse events were observed among the 910 participants. Compared with literature‑reported adverse‑reaction rates of 0.02–0.58% [53,54], this preparation showed superior safety performance. In conclusion, the PUMCH A. alternata allergen extract for SPT diagnosis demonstrates high specificity and a favourable safety profile. This large‑scale clinical validation, comprising nearly a thousand subjects, provides a reliable diagnostic option for the Chinese allergen market. The development of standardized extracts aligns domestic SPT practice with international standards, supporting its clinical implementation as a valuable diagnostic tool, while further refinement of extract quality may enhance sensitivity. \articletype Original Articles Acknowledgment This work was supported by grants from the National Science and Technology Major Project (No. 2014ZX09102041-008 and the Beijing Municipal Science and Technology Plan (No. Z131100006813047). \articletype Original Articles Author Contributions The study was conceived and designed by J.Y., and J.Y., JQ.G., RQ.W., LL.W., H.L., JL.S., YX.Z., K.G., LP.W., ZX.W., LS.L., R.T., L.C., and YY.X. were responsible for patient recruitment. T.X. and X.L. were responsible for data analysis. X.L. and J.Y. were responsible for article writing. All authors have reviewed the final manuscript and accept responsibility for the decision to submit for publication. Conflicts of Interest J.Y., JQ.G., RQ.W., LL.W., H.L., JL.S., YX.Z., K.G., LP.W., ZX.W., LS.L., R.T., L.C., and YY.X. are employees of PUMCH. T.X. and X.L. have nothing to disclose. \articletype Original Articles Reference 1. Kustrzeba-Wójcicka I, Siwak E, Terlecki G, Wolańczyk-Mędrala A, Mędrala W. Alternaria alternata and its allergens: a comprehensive review. Clin Rev Allergy Immunol. 2014 Dec;47(3):354-65. doi: 10.1007/s12016-014-8447-6. PMID: 25205364. 2. Feo Brito F, Alonso AM, Carnés J, Martín-Martín R, Fernández-Caldas E, Galindo PA, Alfaya T, Amo-Salas M. Correlation between Alt a 1 levels and clinical symptoms in Alternaria alternata-monosensitized patients. J Investig Allergol Clin Immunol. 2012;22(3):154-9. PMID: 22697004. 3. Peters JL, Muilenberg ML, Rogers CA, Burge HA, Spengler JD. Alternaria measures in inner-city, low-income housing by immunoassay and culture-based analysis. Ann Allergy Asthma Immunol. 2008 Apr;100(4):364-9. doi: 10.1016/S1081-1206(10)60600-X. PMID: 18450123. 4. O’connor GT, Walter M, Mitchell H, Kattan M, Morgan WJ, Gruchalla RS, Pongracic JA, Smartt E, Stout JW, Evans R, Crain EF, Burge HA. Airborne fungi in the homes of children with asthma in low-income urban communities: The Inner-City Asthma Study. J Allergy Clin Immunol. 2004 Sep;114(3):599-606. doi: 10.1016/j.jaci.2004.05.064. PMID: 15356564. 5. Barnes C, Portnoy J, Sever M, Arbes S Jr, Vaughn B, Zeldin DC. Comparison of enzyme immunoassay-based assays for environmental Alternaria alternata. Ann Allergy Asthma Immunol. 2006 Sep;97(3):350-6. doi: 10.1016/S1081-1206(10)60800-9. PMID: 17042141; PMCID: PMC1876741. 6. Arbes SJ Jr, Gergen PJ, Elliott L, Zeldin DC. Prevalences of positive skin test responses to 10 common allergens in the US population: results from the third National Health and Nutrition Examination Survey. J Allergy Clin Immunol. 2005 Aug;116(2):377-83. doi: 10.1016/j.jaci.2005.05.017. PMID: 16083793. 7. Pulimood TB, Corden JM, Bryden C, Sharples L, Nasser SM. Epidemic asthma and the role of the fungal mold Alternaria alternata. J Allergy Clin Immunol. 2007 Sep;120(3):610-7. doi: 10.1016/j.jaci.2007.04.045. Epub 2007 Jul 10. PMID: 17624415. 8. Katotomichelakis M, Nikolaidis C, Makris M, Proimos E, Aggelides X, Constantinidis TC, Papadakis CE, Danielides V. Alternaria and Cladosporium calendar of Western Thrace: Relationship with allergic rhinitis symptoms. Laryngoscope. 2016 Feb;126(2):E51-6. doi: 10.1002/lary.25594. Epub 2015 Sep 15. PMID: 26371953 9. Prester L. Indoor exposure to mould allergens. Arh Hig Rada Toksikol. 2011 Dec;62(4):371-80. doi: 10.2478/10004-1254-62-2011-2126. PMID: 22202471. 10. Twaroch TE, Curin M, Valenta R, Swoboda I. Mold allergens in respiratory allergy: from structure to therapy. Allergy Asthma Immunol Res. 2015 May;7(3):205-20. doi: 10.4168/aair.2015.7.3.205. Epub 2015 Mar 11. PMID: 25840710; PMCID: PMC4397360. 11. Anees-Hill S, Douglas P, Pashley CH, Hansell A, Marczylo EL. A systematic review of outdoor airborne fungal spore seasonality across Europe and the implications for health. Sci Total Environ. 2022 Apr 20;818:151716. doi: 10.1016/j.scitotenv.2021.151716. Epub 2021 Nov 17. PMID: 34800445; PMCID: PMC8919338. 12. Mari A, Schneider P, Wally V, Breitenbach M, Simon-Nobbe B. Sensitization to fungi: epidemiology, comparative skin tests, and IgE reactivity of fungal extracts. Clin Exp Allergy. 2003 Oct;33(10):1429-38. doi: 10.1046/j.1365-2222.2003.01783.x. PMID: 14519151. 13. Mari A, Schneider P, Wally V, Breitenbach M, Simon-Nobbe B. Sensitization to fungi: epidemiology, comparative skin tests, and IgE reactivity of fungal extracts. Clin Exp Allergy. 2003 Oct;33(10):1429-38. doi: 10.1046/j.1365-2222.2003.01783.x. PMID: 14519151. 14. Crameri R, Garbani M, Rhyner C, Huitema C. Fungi: the neglected allergenic sources. Allergy. 2014 Feb;69(2):176-85. doi: 10.1111/all.12325. Epub 2013 Nov 29. PMID: 24286281.Crameri R, Garbani M, Rhyner C, Huitema C. Fungi: the neglected allergenic sources. Allergy. 2014 Feb;69(2):176-85. doi: 10.1111/all.12325. Epub 2013 Nov 29. PMID: 24286281. 15. Corey JP, Kaiseruddin S, Gungor A. Prevalence of mold-specific immunoglobulins in a Midwestern allergy practice. Otolaryngol Head Neck Surg. 1997 Nov;117(5):516-20. doi: 10.1016/S0194-59989770024-X. PMID: 9374177. 16. Heinzerling, L. M., G. J. Burbach, G. Edenharter, C. Bachert, C. Bindslev-Jensen, S. Bonini, J. Bousquet, L. Bousquet Rouanet, P. J. Bousquet, M. Bresciani, et al. Zuberbier T. GA(2)LEN skin test study I: GA(2)LEN harmonization of skin prick testing: novel sensitization patterns for inhalant allergens in Europe. Allergy. 2009 Oct;64(10):1498-506. doi: 10.1111/j.1398-9995.2009.02093.x. PMID: 19772515. 17. Simon-Nobbe B, Denk U, Pöll V, Rid R, Breitenbach M. The spectrum of fungal allergy. Int Arch Allergy Immunol. 2008;145(1):58-86. doi: 10.1159/000107578. Epub 2007 Aug 20. PMID: 17709917. 18. Bogacka E, Nittner-Marszalska M, Fal AM, Kuzniar J, Nikiel E, Małolepszy J. Uczulenie na alergeny grzybów pleśniowych jako czynnik ryzyka wystapienia astmy oskrzelowej u chorych z alergicznym niezytem nosa [Allergy to mould allergens as a risk factor for bronchial asthma in patients suffering from allergic rhinitis]. Pol Merkur Lekarski. 2003 May;14(83):388-92. Polish. PMID: 12939809. 19. Wanshu L, Chao C, Xuesu M, Dan Z, Weikang Z. Analysis on allergic sensitization characteristics of Alternaria alternata in Chongqing area. Chongqing Medicine. 2019 Nov; 48(21):3633. Chinses. doi: 10.3969/j.issn.1671-8348.2019.21.007 20. Yaochen J, Kaisheng Y, Xiaoxiang C. Study of the Relationship Between Airborne Fung and Asthma in Zhen Jiang City. Practical Preventive Medicine. 2001 JUN 28;8(3):170-172. Chinses. doi: 10.3969/j.issn.1006-3110.2001.03.005. 21. Hanzhong X, Liangqiong Y, Dadong F, Fuyu Z, Shuping H, Haoyi W, Kaiqi C, Zhian W. A survey of airborne fungi and and correlation study with bronchial asthma from 2007 to 2011 in Ezhou. Chinese Journal of Mycology, 2015,12(30):6-7+4. Chinses. 22. Huaying S. Study on relation of fungi allergenicity to intracutaneous test and bronchial asthma. BMU Journal, 2009(2):111-113. Chinses. doi: 10.3969/j.issn.1001-9510.2009.02.011 23. Keying L, Jiangang X, Ping C, Guihua L. A Survey of Airbone Fungi in Shiyan Area. Journal of Yunyang Medical College,1999,18(3):129-132. Chinses. doi:10.3969/j.issn.1006-9674.1999.03.003. 24. Chen C, Dongjun M. Analysis of sensitization characteristics of Alternaria alternata in children with bronchial asthma. International Journal of Respiration. 2022;42(16):1237-1241. Chinses. doi: 10.3760/cma.j.cn131368-20220321-00216. 25. Salo PM, Arbes SJ Jr, Sever M, Jaramillo R, Cohn RD, London SJ, Zeldin DC. Exposure to Alternaria alternata in US homes is associated with asthma symptoms. J Allergy Clin Immunol. 2006 Oct;118(4):892-8. doi: 10.1016/j.jaci.2006.07.037. PMID: 17030243; PMCID: PMC2080575. 26. Heinzerling L, Frew AJ, Bindslev-Jensen C, Bonini S, Bousquet J, Bresciani M, Carlsen KH, van Cauwenberge P, Darsow U, Fokkens WJ, Haahtela T, van Hoecke H, Jessberger B, Kowalski ML, Kopp T, Lahoz CN, Lodrup Carlsen KC, Papadopoulos NG, Ring J, Schmid-Grendelmeier P, Vignola AM, Wöhrl S, Zuberbier T. Standard skin prick testing and sensitization to inhalant allergens across Europe–a survey from the GALEN network. Allergy. 2005 Oct;60(10):1287-300. doi: 10.1111/j.1398-9995.2005.00895.x. PMID: 16134996. 27. Forkel S, Beutner C, Schröder SS, Bader O, Gupta S, Fuchs T, Schön MP, Geier J, Buhl T. Sensitization against Fungi in Patients with Airway Allergies over 20 Years in Germany. Int Arch Allergy Immunol. 2021;182(6):515-523. doi: 10.1159/000512230. Epub 2021 Mar 29. PMID: 33780961; PMCID: PMC8220924. 28. Fernández-Soto R, Navarrete-Rodríguez EM, Del-Rio-Navarro BE, Sienra-Monge JJL, Meneses-Sánchez NA, Saucedo-Ramírez OJ. Fungal Allergy: Pattern of sensitization over the past 11 years. Allergol Immunopathol (Madr). 2018 Nov-Dec;46(6):557-564. doi: 10.1016/j.aller.2018.01.005. Epub 2018 May 5. PMID: 29739683. 29. Patel G, Saltoun C. Skin testing in allergy. Allergy Asthma Proc. 2019 Nov 1;40(6):366-368. doi: 10.2500/aap.2019.40.4248. PMID: 31690371. 30. Position paper: Allergen standardization and skin tests.The European Academy of Allergology and Clinical Immunology [J]. Allergy, 1993, 48: 48- 82. 31. Heinzerling L, Mari A, Bergmann KC, Bresciani M, Burbach G, Darsow U, Durham S, Fokkens W, Gjomarkaj M, Haahtela T, Bom AT, Wöhrl S, Maibach H, Lockey R. The skin prick test - European standards. Clin Transl Allergy. 2013 Feb 1;3(1):3. doi: 10.1186/2045-7022-3-3. PMID: 23369181; PMCID: PMC3565910. 32. Tang R, Lyu X, Liu Y, Wang R, Wang L, Li H, Sun J, Zhi Y, Gu J, Guan K, Wen L, Wang Z, Li L, Cui L, Xu Y, Zhou J, Xu T, Yin J. Diagnostic accuracy and safety of Dermatophagoides pteronyssinus extracts used for skin prick test. Chin Med J (Engl). 2022 Nov 5;135(21):2563-2569. doi: 10.1097/CM9.0000000000002262. PMID: 36583919; PMCID: PMC9945504. 33. Erel F, Sarioglu N, Kose M, Kaymakci M, Gokcen M, Kepekci AH, Arslan M. Intradermal Skin Testing in Allergic Rhinitis and Asthma with Negative Skin Prick Tests. Iran J Allergy Asthma Immunol. 2017 Jun;16(3):193-197. PMID: 28732432. 34. Larrabee YC, Reisacher W. Intradermal testing after negative skin prick testing for patients with high suspicion of allergy. Int Forum Allergy Rhinol. 2015 Jun;5(6):547-50. doi: 10.1002/alr.21512. Epub 2015 Mar 10. Erratum in: Int Forum Allergy Rhinol. 2015 Aug;5(8):770. doi: 10.1002/alr.21619. PMID: 25756229. 35. Jung YG, Cho HJ, Park GY, Min JY, Kim HY, Dhong HJ, Chung SK, Kim SW. Comparison of the skin-prick test and Phadia ImmunoCAP as tools to diagnose house-dust mite allergy. Am J Rhinol Allergy. 2010 May-Jun;24(3):226-9. doi: 10.2500/ajra.2010.24.3459. PMID: 20537291. 36. Traiyan S, Manuyakorn W, Kanchongkittiphon W, Sasisakulporn C, Jotikasthira W, Kiewngam P, Kamchaisatian W, Benjaponpitak S. Skin Prick Test Versus Phadiatop as a Tool for Diagnosis of Allergic Rhinitis in Children. Am J Rhinol Allergy. 2021 Jan;35(1):98-106. doi: 10.1177/1945892420938300. Epub 2020 Jun 27. PMID: 32597210. 37. Bidovec-Stojkovič U, Vachová M, Košnik Ž, Košnik M, Panzner P, Volfand J, Homšak M, Berce V, Korošec P. Methodological and diagnostic relevance of IgEs to recombinant allergens Api m 1 and Ves v 5 determined by the multiplex test ImmunoCAP ISAC. Clin Exp Allergy. 2020 Aug;50(8):981-983. doi: 10.1111/cea.13678. Epub 2020 Jun 30. PMID: 32511822. 38. Tang R, Lyu X, Zhang Y, Chen S, Li H. High house dust mite serum-specific immunoglobulin E indicates a high 5-year rhinitis-asthma conversion rate: a cross-sectional study. Chin Med J (Engl). 2021 Dec 22;135(2):219-221. doi: 10.1097/CM9.0000000000001790. PMID: 34935686; PMCID: PMC8769136. 39. Bignardi D, Comite P, Mori I, Ferrero F, Fontana V, Bruzzone M, Mussap M, Ciprandi G. Allergen-specific IgE: comparison between skin prick test and serum assay in real life. Allergol Select. 2019 Dec 30;3(1):9-14. doi: 10.5414/ALX01891E. PMID: 32176225; PMCID: PMC7066680. 40. Wagner N, Rudert M. Sensitivity and specificity of standardised allergen extracts in skin prick test for diagnoses of IgE-mediated respiratory allergies. Clin Transl Allergy. 2019 Feb 18;9:8. doi: 10.1186/s13601-019-0248-9. PMID: 30820315; PMCID: PMC6378716. 41. Mohammad HR, Belgrave D, Kopec Harding K, Murray CS, Simpson A, Custovic A. Age, sex and the association between skin test responses and IgE titres with asthma. Pediatr Allergy Immunol. 2016 May;27(3):313-9. doi: 10.1111/pai.12534. Epub 2016 Feb 8. PMID: 26766520. 42. Nam YH, Lee SK. Comparison between skin prick test and serum immunoglobulin E by CAP system to inhalant allergens. Ann Allergy Asthma Immunol. 2017 May;118(5):608-613. doi: 10.1016/j.anai.2017.03.005. PMID: 28477791. 43. Gendo K, Larson EB. Evidence-based diagnostic strategies for evaluating suspected allergic rhinitis. Ann Intern Med. 2004 Feb 17;140(4):278-89. doi: 10.7326/0003-4819-140-4-200402170-00010. PMID: 14970151. 44. Bartko EA, Elberling J, Mosbech H. The shape of and applied weight on skin prick lancets critically affect the wheal size in the skin prick test. World Allergy Organ J. 2024 Jun 13;17(6):100915. doi: 10.1016/j.waojou.2024.100915. PMID: 38974945; PMCID: PMC11225002. 45. Chiaranairungroj M, Chatchatee P, Srituravanich W. The effect of applied force and device design on skin prick test performance. Ann Allergy Asthma Immunol. 2023 Mar;130(3):312-316. doi: 10.1016/j.anai.2022.11.014. Epub 2022 Nov 25. PMID: 36436784. 46. Seys SF, Roux K, Claes C, Van Cappellen L, Werpin L, Loeckx D, Sebrechts H, Gorris S, Van Gerven L. Skin Prick Automated Test device offers more reliable allergy test results compared to a manual skin prick test. Rhinology. 2024 Apr 1;62(2):216-222. doi: 10.4193/Rhin23.330. PMID: 37983015. 47. Kespohl S, Maryska S, Bünger J, Hagemeyer O, Jakob T, Joest M, Knecht R, Koschel D, Kotschy-Lang N, Merget R, Mülleneisen NK, Rabe U, Röseler S, Sander I, Stollewerk D, Straube H, Ulmer HM, van Kampen V, Walusiak-Skorupa J, Wiszniewska M, Wurpts G, Brüning T, Raulf M. How to diagnose mould allergy? Comparison of skin prick tests with specific IgE results. Clin Exp Allergy. 2016 Jul;46(7):981-91. doi: 10.1111/cea.12733. Epub 2016 May 3. PMID: 27027397. 48. Kespohl S, Maryska S, Zahradnik E, Sander I, Brüning T, Raulf-Heimsoth M. Biochemical and immunological analysis of mould skin prick test solution: current status of standardization. Clin Exp Allergy. 2013 Nov;43(11):1286-96. doi: 10.1111/cea.12186. PMID: 24152161. 49. Esch RE. Manufacturing and standardizing fungal allergen products. J Allergy Clin Immunol. 2004 Feb;113(2):210-5. doi: 10.1016/j.jaci.2003.11.024. PMID: 14767431. 50. Grier TJ, Hazelhurst DM, Duncan EA, West TK, Esch RE. Major allergen measurements: sources of variability, validation, quality assurance, and utility for laboratories, manufacturers, and clinics. Allergy Asthma Proc. 2002 Mar-Apr;23(2):125-31. PMID: 12001791. 51. Vailes L, Sridhara S, Cromwell O, Weber B, Breitenbach M, Chapman M. Quantitation of the major fungal allergens, Alt a 1 and Asp f 1, in commercial allergenic products. J Allergy Clin Immunol. 2001 Apr;107(4):641-6. doi: 10.1067/mai.2001.114118. PMID: 11295652. 52. Aden E, Weber B, Bossert J, Teppke M, Frank E, Wahl R, Fiebig H, Cromwell O. Standardization of Alternaria alternata: extraction and quantification of alt a 1 by using an mAb-based 2-site binding assay. J Allergy Clin Immunol. 1999 Jul;104(1):128-35. doi: 10.1016/s0091-6749(99)70124-7. PMID: 10400850. 53. Swender DA, Chernin LR, Mitchell C, Sher T, Hostoffer R, Tcheurekdjian H. The rate of epinephrine administration associated with allergy skin testing in a suburban allergy practice from 1997 to 2010. Allergy Rhinol (Providence). 2012 Fall;3(2):e55-60. doi: 10.2500/ar.2012.3.0034. Epub 2012 Dec 12. PMID: 23342290; PMCID: PMC3548609. 54. Guan K, Zhou JX, Wang RQ, Yin J, Wang LL, Zhi YX, Sun JL, Li H, Wen LP, Gu JQ, Tang R, Wang ZX, Li LS, Xu T. [The clinical value of China Savin pollen extract used for skin prick test]. Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2018 Feb;32(3):161-166. Chinese. doi: 10.13201/j.issn.1001-1781.2018.03.001. PMID: 29775012. 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Keywords allergy diagnosis clinical immunology ige Authors Affiliations XIN LI 0009-0003-5749-6326 Peking Union Medical College Hospital View all articles by this author Jian-Qing Gu Peking Union Medical College Hospital View all articles by this author Ruiqi Wang Peking Union Medical College Hospital View all articles by this author Lianglu Wang Peking Union Medical College Hospital View all articles by this author Hong Li Peking Union Medical College Hospital View all articles by this author Jin-Lu Sun 0000-0002-9991-4245 Peking Union Medical College Hospital View all articles by this author Yu Xiang Zhi 0000-0001-7539-6650 Peking Union Medical College Hospital View all articles by this author Kai Guan 0000-0003-0850-5874 Peking Union Medical College Hospital View all articles by this author Liping Wen Peking Union Medical College Hospital View all articles by this author Zixi Wang Peking Union Medical College Hospital View all articles by this author Lisha Li Peking Union Medical College Hospital View all articles by this author Rui Tang 0000-0001-5889-3858 Peking Union Medical College Hospital View all articles by this author Le Cui Peking Union Medical College Hospital View all articles by this author Ying-Yang Xu 0000-0002-0583-1925 Peking Union Medical College Hospital View all articles by this author Tao Xu Chinese Academy of Medical Sciences and Peking Union Medical College Institute of Basic Medical Sciences View all articles by this author Jia Yin 0000-0002-7858-4259 [email protected] Peking Union Medical College Hospital View all articles by this author Metrics & Citations Metrics Article Usage 205 views 65 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation XIN LI, Jian-Qing Gu, Ruiqi Wang, et al. 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