Safety of Direct Drug Provocation for the Evaluation of Penicillin Allergy in Low-Risk Adults.

BACKGROUND: About 10% of patients have a penicillin allergy label, but less than 5% of them are actually allergic. Unnecessary penicillin avoidance is associated with serious medical consequences. Given the growing number of these labels, it is imperative that our diagnostic strategy for penicillin allergy be as efficient as possible. The validity of traditionally used skin tests (STs) has been questioned, whereas drug provocation testing (DPT), the criterion standard, without previous ST appears very safe in most cases. OBJECTIVE: To evaluate the safety of direct DPT without consideration for ST results and the validity of ST in the diagnosis of penicillin allergy. METHODS: In this prospective cohort study without a control group, we recruited patients consulting an allergist for penicillin allergy. Patients underwent ST followed by DPT regardless of ST results. Patients with anaphylaxis to penicillin within the past 5 years or a severe delayed reaction were excluded, as were those with significant cardiorespiratory comorbidity. RESULTS: None of the 1002 recruited patients had a serious reaction to DPT. Ten (1.0%) had a mild immediate reaction, of whom only 1 (0.1%) was considered likely IgE-mediated. The positive and negative predictive values of ST for an immediate reaction were 3.6% and 99.1%, respectively. CONCLUSIONS: In a low-risk adult population reporting penicillin allergy, ST has very poor positive predictive value. Direct DPT without ST is safe and appears to be an ideal diagnostic strategy to remove penicillin allergy labels that could be implemented in first-line practice.

[Retrospective analysis of perioperative anaphylactic shock induced by cefuroxime].

This study investigated the characteristics and frequency of perioperative anaphylactic shock induced by cefuroxime, so as to provide a reference for the safe and rational use of cefuroxime in the perioperative period. Cases of perioperative anaphylactic shock caused by cefuroxime in our hospital from 2011 to 2021 were extracted from the Adverse Drug Reaction Monitoring System. Literature reporting adverse drug reactions (ADR) including cefuroxime-induced anaphylactic shock in perioperative settings was collected from the CNKI, VIP, Wanfang, PubMed, and Web of Science databases from their respective inception to May 2022. Statistical analysis was performed for all cases of cefuroxime-induced perioperative anaphylactic shock. A total of 31 patients were included [13 men (48.1%) and 14 women (51.9%)], most of whom were over 60 years old (n=16, 59.3%); 9 (29.0%) patients had a history of drug allergy; 5 (16.1%) patients had received skin tests, but with negative results; 28 (90.3%) patients received treatment intravenously; 22 (71.0%) patients were treated after anesthesia. For 20 (64.5%) patients the ADR occurred within 10 minutes after anesthesia. The main manifestations were hypotension, dyspnea, rash, and tachycardia. For all patients, symptoms resolved after withdrawal of the drug and active rescue, and there were no deaths. A history of allergy and skin test findings may have limitations in predicting perioperative anaphylactic shock caused by cefuroxime; greater vigilance should be exercised when using cefuroxime in the perioperative period. Close monitoring is recommended for patients undergoing treatment with cefuroxime. Rescue therapy should be administered for allergic shock, and suitable response measures must be taken in a timely manner to ensure the safety of patients.

Direct oral challenge for immediate and non-immediate beta-lactam allergy in children: A real-world multicenter study.

BACKGROUND: Allergy to beta-lactam antibiotics (BLA) is frequently suspected in children, but a drug provocation test (DPT) rules it out in over 90% of cases. Direct oral DPT (DODPT), without skin or other previous tests, is increasingly been used to delabel non-immediate BLA reactions. This real-world study aimed to assess the safety and effectiveness of DODPT in children with immediate and non-immediate reactions to BLAs. METHODS: Ambispective registry study in children (<15 years), attended between 2016 and 2023 for suspected BLA allergy in 15 hospitals in Spain that routinely perform DODPT. RESULTS: The study included 2133 patients with generally mild reactions (anaphylaxis 0.7%). Drug provocation test with the implicated BLA was performed in 2014 patients (94.4%): 1854 underwent DODPT (86.9%, including 172 patients with immediate reactions). One hundred forty-five (7.2%) had symptoms associated with DPT, although only four reactions were severe: two episodes of anaphylaxis and two of drug-induced enterocolitis syndrome, which resolved rapidly with treatment. Of the 141 patients with mild reactions in the first DPT, a second DPT was considered in 87 and performed in 57, with 52 tolerating it without symptoms. Finally, BLA allergy was ruled out in 90.9% of the sample, confirmed in 3.4%, and remained unverified, usually due to loss to follow-up, in 5.8%. CONCLUSIONS: Direct oral DPT is a safe, effective procedure even in immediate mild reactions to BLA. Many reactions observed in DPT are doubtful and require confirmation. Severe reactions are exceptional and amenable to treatment. Direct oral DPT can be considered for BLA allergy delabeling in pediatric primary care.

Folliculitis might be associated with pathergy-positivity in patients with Behçet syndrome.

Pathergy test indicates nonspecific hyper-reactivity of the skin to aseptic trauma in Behçet syndrome (BS) and is considered as an adjunctive diagnostic test with a good specificity albeit with low sensitivity. We tested the hypothesis that a relationship exists between active clinical manifestations of BS and the pathergy-positivity when performed simultaneously. Pathergy test and detailed dermatologic examination were done in 105 BS patients (60M/45F); who were seen consecutively at the multi-disciplinary BS outpatient clinic in a single tertiary center. Information regarding demographic and clinical characteristics, pathergy test results at diagnosis, and details about treatment were obtained from patient charts. Disease activity was assessed using Behçet Disease Current Activity Form. Among 105 patients, 27 (25.7%) were pathergy-positive at the time of the study visit whereas 40.9% were pathergy-positive at the time of the diagnosis. There was no relation between pathergy test and patient age or disease duration, either. Pathergy-positivity was significantly more common in patients with folliculitis compared to those without folliculitis (40.7% vs 19.2%; P = .026). The test was also positive in all 3 patients with leg ulcers due to venous stasis. We found that among all skin-mucosa lesions only the presence of folliculitis was associated with pathergy positivity with statistical significance. It was also remarkable that the current pathergy was positive in all 3 patients with active leg ulcers but this finding warrants further studies because of the low patient numbers.

Use of oral penicillin challenge in low-risk penicillin allergy.

Overview of: Copaescu AM, Vogrin S, James F, et al. Efficacy of a clinical decision rule to enable direct oral challenge in patients with low-risk penicillin allergy: The PALACE randomized clinical trial. JAMA Intern Med 2023;183:944-52.

In Vitro and In Vivo Methods for Analysis of Nanoparticles' Potential to Induce Delayed-Type Hypersensitivity Reactions.

Delayed-type hypersensitivity (DTH) reactions are among the common reasons for drug withdrawal from clinical use during the post-marketing stage. Several in vivo methods have been developed to test DTH responses in animal models. They include the local lymph node assay (LLNA) and local lymph node proliferation assay (LLNP). While LLNA is instrumental in testing topically administered formulations (e.g., creams), the LLNP was proven to be predictive of drug-mediated DTH in response to small molecule pharmaceuticals. Global efforts in reducing the use of research animals lead to the development of in vitro models to predict test-materials' mediated DTH. Two such models include the analysis of surface marker expression in human cell lines THP-1 and U-937. These tests are known as the human cell line activation test (hCLAT) and myeloid U937 skin sensitization test (MUSST or U-SENS), respectively. Here we describe experimental procedures for all these methods, discuss their in vitro-in vivo correlation, and suggest a strategy for applying these tests to analyze engineered nanomaterials and nanotechnology-formulated drug products.

Identificación y caracterización de herramientas para evaluar la alergia a las penicilinas: Revisión estructurada / Identification and characterization of tools used to assess penicillin allergy: structured review

Introducción: Las reacciones alérgicas son uno de los problemas de seguridad más graves asociadas al uso de medicamentos, siendo la alergia a los antibióticos betalactámicos la más prevalente. Las pruebas de alergia a las penicilinas pueden ayudar a identificar pacientes hospitalizados y ambulatorios que podrían tolerar y usar de manera segura este grupo de antibióticos y evitar rótulos que limiten el uso de antibióticos betalactámicos por tiempo indefinido. Objetivo: Identificar las herramientas disponibles en la literatura para valorar el antecedente de alergia a las penicilinas y proponer una herramienta que consolide la información extraída. Metodología: Revisión estructurada en PubMed/MEDLINE entre 1 junio 2015 hasta 30 noviembre 2022, utilizando los términos MeSH: (((“skin tests”[MeSH Terms]) OR (“skin irritancy tests”[MeSH Terms])) AND (“penicillins”[All Fields])) AND (“drug hypersensitivity”[MeSH Terms]). Publicaciones en inglés y español con acceso a texto completo y estudios realizados en humanos, sobre herramientas disponibles para evaluar la alergia a penicilinas fueron incluidos. Resultados: Se identificaron201 artículos, de los cuales se incluyeron 108. Dentro de las herramientas para evaluar la alergia a las penicilinas se identificaron: a) pruebas in vivo: pruebas cutáneas, pruebas de provocación oral, pruebas del parche; y b) pruebas in vitro: pruebas de IgE específica, determinación de triptasa, histamina. De los 1181 pacientes reportados con alergia a las penicilinas, sólo el 2 % de ellos se confirmó la presencia de alergia. Conclusión: Las pruebas cutáneas y de provocación oral sumado a algunas combinaciones in vivo/in vitro, fueron las herramientas más utilizadas para evaluar la alergia a las penicilinas. (AU)

Introduction: Allergic reactions are one of the most serious safety problems associated with the use of medications, with allergy to beta-lactam antibiotics being the most prevalent. In fact, the American Academy of Allergy, Asthma and Immunology (AAAAI) states that penicillin allergy testing can help identify inpatients and outpatients who could safely tolerate and use this group of antibiotics and avoid labels that limit the use of beta-lactam antibiotics indefinitely. Objective: To identify the tools available in the literature to assess the history of allergy to penicillins and propose a tool that consolidates the information extracted. Methodology: Structured review on PubMed/MEDLINE between June 1, 2015 until November 30, 2022; using the search terms MeSH: (((“skin tests”[MeSH Terms]) OR (“skin irritancy tests”[MeSH Terms])) AND (“penicillins”[All Fields])) AND (“drug hypersensitivity”[MeSH Terms]). Papers in English and Spanish with access to full text and human trials, regarding available tools used to evaluate penicillin allergies were included. Results: A total of 201 articles were identified, of which after an independent evaluation, 108 were included. Among the tools to evaluate penicillin allergy, in vivo tests were identified: skin tests, oral provocation tests, patch tests and in vitro tests: specific IgE tests, determination of tryptase, histamine, T lymphocytes and basophilic activation tests. Of the patients (1181) reported with penicillin allergy, 905 (77 %) had their allergy assessed with skin testing or oral challenge tests, and only 2 % of them had a confirmed allergic reaction. Conclusion: Skin tests and oral provocation tests added to some in vivo/in vitro combinations were the most used tools to evaluate penicillin allergy. (AU)

Safety of direct oral provocation test to delabel reported mild beta-lactam allergy in infants.

BACKGROUND: Around 10% of people report a drug allergy and avoid some medications because of fear of allergic reactions. However, only after a proper diagnostic workup can some of these reactions be confirmed as allergic or nonallergic hypersensitivities. Beta-lactams (BLs) are the most common medication suspected of being involved in drug hypersensivity reactions (DHRs) in children. Recently, direct oral provocation tests (DPT) with BLs gained popularity within pediatric populations as a tool for delabeling children with suspected BL allergies. This study aimed to evaluate the safety of direct provocation tests in infants with mild cutaneous non-immediate reactions to BLs. METHODS: The authors retrospectively analyzed the data of 151 infants between 2015 and 2022, referred for evaluating a suspected allergy to BLs that occurred before age 24 months. RESULTS: The mean age of the children, including 55% male kids, at the suspected reaction was 15.9 months and the mean age at the time of the DPT was 39.6 months. In most cases, antibiotics were prescribed to treat common upper respiratory infections, such as acute otitis (54.3%) and acute tonsillitis (27.2%). Amoxicillin was considered the culprit drug in 62.9% of the cases, and the combination of amoxicillin-clavulanic acid in the case of 33.8% of children. The most frequent associated cutaneous clinical manifestations were maculopapular exanthema in 74.8% and delayed urticaria/angioedema in 25.2%. Of the 151 infants evaluated, parents of 149 infants agreed for a direct DPT, and only three had a positive test (2%). Symptoms resulting from the DPT were mild and easily treatable. CONCLUSIONS: A direct DPT without prior tests is a safe and effective procedure to delabel BL allergy, even in infants. The authors wish to emphasize the importance of properly validating BL allergy suspicions by promoting appropriate diagnostic procedures in infants as, in most cases, DHRs can be excluded and there is no need for further therapeutic restrictions.

No remission in 60% of those with childhood-onset asthma - A population-based cohort followed from 8 to 28 years of age.

BACKGROUND: Although remission occur, childhood-onset asthma may persist until adulthood. Since few longitudinal population-based studies have followed a cohort from childhood until adulthood, the knowledge on predictors of persistence of asthma is sparse. AIM: To estimate persistence of asthma from 8 to 28 years and its associated factors. METHODS: Within the OLIN (Obstructive Lung Disease in Northern Sweden) studies, a cohort was recruited in 1996 (age 8y, n = 3430) and followed annually with questionnaires about asthma and risk factors until 19y. Clinical examinations included skin prick tests (at 8, 12 and 19y) and lung function tests (17 and 19y) whereof a subsample performed bronchial hyperreactivity test. We identified n = 248 with asthma at 8y whereof 170 (69%) participated in a follow-up at 28y (73% of possible to invite). RESULTS: Of the 170 participants at 28y, 105 (61.8%) had persistent asthma (women: 49/76, 64.5%; men: 56/94, 59.6%, p = 0.513). Factors collected at recruitment: allergic sensitization (OR7.8, 95%CI 3.0-20.2), severe respiratory infection (OR2.6, 95%CI 1.1-6.3) and higher asthma severity score (OR1.6, 95%CI 1.1-2.4) were associated with asthma at 28y after adjustment for sex, family history of asthma, breastfeeding <3 months and eczema. Replacing allergic sensitization with rhinoconjunctivitis in the model yielded OR3.4 (95%CI 1.5-8.0). Bronchial hyperreactivity at age 17y associated with asthma at 28y (OR9.0, 95%CI 1.7-47.0). CONCLUSIONS: Among children with asthma onset by 8y, 62% still had asthma at age 28 years. Persistent asthma was associated with allergic sensitization, rhinoconjunctivitis, severe respiratory infection, a more severe asthma and bronchial hyperreactivity.

A multicentre observational study to investigate feasibility of a direct oral penicillin challenge in de-labelling 'low risk' patients with penicillin allergy by non-allergy healthcare professionals (SPACE study): Implications for healthcare systems.

OBJECTIVE: The huge burden of inaccurate penicillin allergy labels (PALs) is an important driver of antimicrobial resistance. This is magnified by insufficient allergy specialists and lack of 'point-of-care' tests. We investigated the feasibility of non-allergy healthcare professionals (HCPs) delivering direct oral penicillin challenges (DPCs) for penicillin allergy de-labelling. METHODS: This prospective observational study was conducted in three hospitals in England across three settings (acute medical, pre-surgical and haematology-oncology). Patients with a PAL were screened and stratified as low risk/high risk. Low risk patients (non-immune mediated symptoms, benign rash, tolerated amoxicillin since and family history) underwent a DPC. RESULTS: N = 2257 PALs were screened, 1054 were eligible; 643 were approached, 373 declined, 270 consented and 259 risk stratified (low risk = 155; high risk = 104). One hundred and twenty-six low risk patients underwent DPC, 122 (96.8%) were de-labelled with no serious allergic reactions. Conversion rate from screening-to-consent was 12% [3.3% and 17.9% in acute and elective settings respectively; odds ratios for consent were 3.42 (p < 0.001) and 5.53 (p < 0.001) in haematology-oncology and pre-surgical setting respectively. Common reasons for failure to progress in the study included difficulty in reaching patients, clinical instability/medical reasons, lacking capacity to consent and psychological factors. INTERPRETATION: DPCs can be delivered by non-allergy HCPs. A high proportion of patients with PALs did not progress in the study pathway. Strategies to deliver DPC at optimal points of the care pathway are needed to enhance uptake. Elective settings offer greater opportunities than acute settings for DPC. The safety and simplicity of DPCs lends itself to adoption by healthcare systems beyond the UK, including in resource-limited settings.

Local anesthetics allergy in children: Evaluation of diagnostic tests with Real-Life data.

BACKGROUND: Local anesthetic (LA) drugs are commonly used in clinical practice to provide effective analgesia, including in dentistry and minor surgical procedures. The perception of a high risk of allergy in daily applications leads to the referral of atopic patients and those with other drug allergies to allergy clinics for the evaluation of allergic reactions to LA. The aim of this study was to determine who should be referred to the allergy clinic for LA allergy testing, assess the frequency of LA allergy in pediatric patients, and identify the negative predictive value of skin tests in diagnosis. METHODS: January 2017-July 2023, the clinical and laboratory data, as well as the results of drug allergy tests, of patients referred to our pediatric allergy clinic by dentists and physicians performing minor surgical procedures with suspected LA allergy were retrospectively evaluated. RESULTS: Our study included a total of 153 patients, comprising 84 girls (54.9%) and 69 boys (45.1%), with a mean age of 8.9 (±3.3) years. The most common reason for referral was a history of non-LA drug allergies (n = 66, 43.2%), followed by asthma (n = 25, 16.3%). Hypersensitivity reactions (HRs) with LA were most commonly associated with articaine (n = 7, 4.8%), followed by lidocaine (n = 6, 4.1%). When intradermal tests were evaluated, 17 patients (11.1%) had a positive test result. The positivity for lidocaine was 70.6% (n = 12), and prilocaine was 29.4% (n = 5). Subcutaneous provocation was administered to 109 patients (71.2%), and one patient exhibited local erythema and swelling with prilocaine. CONCLUSION: Although LA allergy is a rare occurrence, consultations of this nature are frequently requested from allergy clinics in real life. Considering the negative predictive value of skin tests performed with LA drugs, the reaction rate appears to be low in patients with atopy or other drug allergies. It is crucial for all relevant healthcare professionals to be knowledgeable about the appropriate approach to suspected LA allergies to avoid unnecessary tests. To the best of our knowledge, our study is the most comprehensive work in the literature that evaluates the results of diagnostic tests in children referred with a suspicion of LA allergy.

Heterogeneity of sensitization profiles and clinical phenotypes among patients with seasonal allergic rhinitis in Southern European countries-The @IT.2020 multicenter study.

BACKGROUND: Pollen allergy poses a significant health and economic burden in Europe. Disease patterns are relatively homogeneous within Central and Northern European countries. However, no study broadly assessed the features of seasonal allergic rhinitis (SAR) across different Southern European countries with a standardized approach. OBJECTIVE: To describe sensitization profiles and clinical phenotypes of pollen allergic patients in nine Southern European cities with a uniform methodological approach. METHODS: Within the @IT.2020 multicenter observational study, pediatric and adult patients suffering from SAR were recruited in nine urban study centers located in seven countries. Clinical questionnaires, skin prick tests (SPT) and specific IgE (sIgE) tests with a customized multiplex assay (Euroimmun Labordiagnostika, Lübeck, Germany) were performed. RESULTS: Three hundred forty-eight children (mean age 13.1 years, SD: 2.4 years) and 467 adults (mean age 35.7 years SD: 10.0 years) with a predominantly moderate to severe, persistent phenotype of SAR were recruited. Grass pollen major allergenic molecules (Phl p 1 and/or Phl p 5) ranged among the top three sensitizers in all study centers. Sensitization profiles were very heterogeneous, considering that patients in Rome were highly poly-sensitized (sIgE to 3.8 major allergenic molecules per patient), while mono-sensitization was prominent and heterogeneous in other cities, such as Marseille (sIgE to Cup a 1: n = 55/80, 68.8%) and Messina (sIgE to Par j 2: n = 47/82, 57.3%). Co-sensitization to perennial allergens, as well as allergic comorbidities also broadly varied between study centers. CONCLUSIONS: In Southern European countries, pollen allergy is heterogeneous in terms of sensitization profiles and clinical manifestations. Despite the complexity, a unique molecular, multiplex, and customized in-vitro IgE test detected relevant sensitization in all study centers. Nevertheless, this geographical diversity in pollen allergic patients imposes localized clinical guidelines and study protocols for clinical trials of SAR in this climatically complex region.

The use of inhibition assay in Api g 7 suspected allergy in a female patient with anaphylaxis: A case report.

The symptoms of celery allergy are mainly presented as oral allergy symptom, but there are several case reports of patients who experienced anaphylaxis. Defensin (Api g 7), as a novel allergen in celery root, was described in 2022 r. The female patient had a history of several episodes of dyspnea and cough, associated with ingestion of spice mixes containing dried celery. Up to the point of hospitalization, there were no objective tests, either sIgE or skin prick tests, that would confirm celery sensitization. During hospitalization, patient had a positive double-blind placebo-controlled food challenge with cooked celery. The patient was sensitized to mugwort defensin Art v 1. An inhibition assay with celery allergen extract was performed to prove cross-sensitization between Art v 1 and celery allergen responsible for symptoms in the patient. In conclusion, Api g 7 is an important celery allergen that can be responsible for severe reactions. Its cross-reactivity with Art v 1 is characteristic. Negative diagnostic tests with celery do not exclude Api g 7 sensitization.

Comparison of the passive mast cell activation test with the basophil activation test for diagnosis of perioperative rocuronium hypersensitivity.

BACKGROUND: Rocuronium is a major cause of perioperative hypersensitivity (POH). Skin tests (STs) and quantification of specific immunoglobulin E antibodies (sIgEs) can yield incongruent results. In such difficult cases, the basophil activation test (BAT) can be helpful. Here, we evaluated the passive mast cell activation test (pMAT) as a substitute of BAT as part of the diagnostic tests for rocuronium allergy. METHODS: Sera from patients with a suspected POH reaction potentially related to rocuronium were included. All patients had a complete diagnostic investigation, including STs, quantification of sIgEs to morphine and rocuronium, and BAT. For execution of pMAT, human mast cells were generated from healthy donor peripheral blood CD34+ progenitor cells and sensitised overnight with patient sera. RESULTS: In total, 90 sera were studied: 41 from ST+sIgE+ patients, 13 from ST-sIgE- patients, 20 from ST+sIgE- patients, and 16 from ST-sIgE+ patients. According to BAT results, patients were further allocated into subgroups. Of the 38 BAT+ patients, 25 (66%) showed a positive pMAT as well. Of the 44 BAT- patients, 43 (98%) also showed a negative pMAT. Mast cells that were not passively sensitised did not respond to rocuronium. CONCLUSIONS: We show that the pMAT, in many cases, can substitute for BAT in the diagnosis of rocuronium hypersensitivity and advance diagnosis in difficult cases with uncertain ST or sIgE results when BAT is not locally available.

The role of skin tests with polyethylene glycol and polysorbate 80 in the vaccination campaign for COVID-19: results from an Italian multicenter survey.

Summary: Background. International guidelines suggested skin tests with Polyethylene-glycol (PEG) and polysorbate 80 (PS-80), to investigate a possible hypersensitivity to these excipients either to identify subjects at risk of developing allergic reactions to Covid-19 vaccines, or in patients with suspected IgE mediated hypersensitivity reactions (HR) to the Covid-19 vaccine. The main purpose of this study was to investigate the prevalence of PEG and PS sensitization in patients with a clinical history of HR to drugs containing PEG/PS and in patients with a suspected Covid-19 vaccine immediate HR. Methods. This was a multicenter retrospective study conducted by allergists belonging to 20 Italian medical centers. Skin testing was performed in 531 patients with either a clinical history of suspected hypersensitivity reaction (HR) to drugs containing PEG and/or PS-80 (group 1:362 patient) or a suspected HR to Covid-19 vaccines (group 2: 169 patient), as suggested by the AAIITO/SIAAIC guidelines for the "management of patients at risk of allergic reactions to Covid-19 vaccines" [1]. Results. 10/362 (0.02%) had positive skin test to one or both excipients in group 1, 12/169 (7.1%) in group 2 (p less than 0.01). In group 2 HRs to Covid-19 vaccines were immediate in 10/12 of cases and anaphylaxis occurred in 4/12 of patients. Conclusions. The positivity of skin test with PEG and or PS before vaccination is extremely rare and mostly replaceable by an accurate clinical history. Sensitization to PEG and PS has to be investigated in patients with a previous immediate HR to a Covid-19 vaccine, in particular in patients with anaphylaxis.

Exploring the Autoimmune Pathogenesis in Severe Asthma.

INTRODUCTION: Severe asthma has a poor response to hormone therapy and a poor level of control, so the discovery of new pathogenetic mechanisms is important for diagnosing and treating severe asthma. IL-35 may play a protective role in autoimmune diseases by directly or indirectly inhibiting the secretion of IL-17, which is an important proinflammatory factor involved in the occurrence and development of autoimmune diseases. The autologous serum skin test (ASST) is a good sensitivity and specificity screening test for autoimmune functional autoantibodies. We compared the levels of IL-35 and IL-17 in serum samples, the positive rate of ASST, the level of exhaled nitric oxide (FeNO), and the atopic constitution in patients with severe asthma to those with mild-to-moderate asthma so as to explore the possible autoimmune pathogenesis of severe asthma. METHODS: Patients with mild-to-moderate and severe asthma were enrolled. Their age, gender, smoking history, family history of asthma, history of allergic rhinitis, positive allergen results, serum total IgE (TlgE), allergen-specific IgE (slgE), routine blood, ASST results, and FeNO test results were compared and analyzed. The IL-35 and IL-17 levels in serum samples from both groups were measured by enzyme-linked immunosorbent assay for comparison and analysis. The SPSS 22.0 software package was used for statistical analysis. RESULTS: A total of 50 patients with mild-to-moderate asthma and 31 patients with severe asthma were included in this study. The proportion of patients with a history of smoking and a family history of asthma was significantly higher in the severe asthma group compared to the mild-to-moderate asthma group (all p < 0.05); the number of positive allergen tests was significantly lower in patients with severe asthma compared to those with mild-to-moderate asthma (p < 0.001). The rate of positive ASST was significantly higher in patients with severe asthma than in patients with mild-to-moderate asthma (p < 0.05). Serum IL-17 levels were significantly higher in patients with severe asthma than in patients with mild-to-moderate asthma (p < 0.05), but serum IL-35 level between the two group was not significantly different (p = 0.113). ASST-positive patients had a statistically significant increase in the risk of developing severe asthma, while patients with allergen positive were less likely to develop severe asthma (positive ASST: OR = 5.277, p = 0.024; allergen positivity: OR = 0.123, p = 0.001). CONCLUSIONS: IL-35 has a weaker inhibitory effect on high IL-17 expression in patients with severe asthma, and the rate of positive ASST was significantly higher in patients with severe asthma, which all suggested the possibility of autoimmune pathogenesis in patients with severe asthma.