免疫球蛋白A缺陷（IgAD）是一种常见疾病，其遗传缺陷尚未知晓，其特点是IgA减少或缺失，而其他亚型和特异性抗体正常。患有该疾病的患者表现出一系列临床表现，包括感染、自身免疫性疾病、恶性肿瘤和过敏性疾病。本研究旨在评估其患病率并对其进行分类。我们在PubMed、Web of Science和Scopus数据库中搜索符合条件的研究，其中包含从可得出的最早日期到2022年1月的标准关键词。使用随机效应模型计算了临床表现患病率及其相应的95%置信区间的汇总估计值。其中，最常见的临床表现属于感染（64.8%），其次是过敏性疾病（26.16%）和自身免疫性疾病（22.0%）。在本研究中，IgA选择性缺陷是IgAD中最大的一组，其中乳糜泻（6.57%）、炎症性肠病（4.01%）和类风湿性关节炎（3.80%）是最常见的自身免疫性疾病。与此同时，最常见的感染为呼吸道感染、真菌感染和胃肠道感染，分别为50.74%、18.48%和15.79%。此外，哮喘、过敏性鼻炎和过敏性结膜炎的总患病率分别为19.06%、15.46%和11.68%，被报告为最普遍的过敏性疾病。我们的研究结果表明，除了未诊断的IgAD患者外，IgAD患者表现出广泛的临床表现。感染、过敏和自身免疫病是最常见的临床表现。IgA和IgG亚型缺乏的同时出现可能与感染易感性增加有关。考虑到在随访过程中发生新的临床并发症的可能性，应定期评估IgAD患者。© 2023年。加拿大过敏与临床免疫学会。

Immunoglobulin A deficiency (IgAD) is a common disease with an unknown genetic defect, characterized by the decreased or absent IgA with other isotypes normal, normal subclasses, and specific antibodies. Patients with this disorder represent a spectrum of clinical manifestations including infections, autoimmune disorders, malignancy, and allergic diseases. The current study aimed to evaluate their prevalence and categorized them.We searched PubMed, Web of Science, and Scopus databases to find eligible studies from the earliest available date to January 2022 with standard keywords. Pooled estimates of clinical manifestations prevalence and the corresponding 95% confidence intervals were calculated using random-effects models.The most prevalent clinical manifestations belonged to infection (64.8%) followed by allergic diseases (26.16%) and autoimmunity (22.0%), respectively. In selective IgA deficiency patients as the largest group of IgAD in current study, celiac disease (6.57%), Inflammatory bowel disease (4.01%), and rheumatoid arthritis (3.80%) were the most prevalent autoimmunity. Meanwhile, the most frequent infection was respiratory tract infection, fungal infection, and gastrointestinal infection at 50.74%, 18.48%, and 15.79%, respectively. In addition, the pooled prevalence of asthma, allergic rhinitis, and allergic conjunctivitis were 19.06%, 15.46%, and 11.68%, respectively which were reported as the most widespread allergic diseases.Our results showed that apart from undiagnosed IgAD patients, IgAD patients represent a wide range of clinical manifestations. Infection, allergy, and autoimmunity are the most common clinical manifestations. The concurrent presence of IgA and IgG subtypes deficiency could be associated with increased susceptibility to infection. Considering the probability of developing new clinical complications during follow-up, periodic assessments of IgAD patients should be inspected.© 2023. Canadian Society of Allergy & Clinical Immunology.