Domínguez O, Giner M T, Alsina L, Martín M A, Lozano J, Plaza A M
Servicio de Inmunología y Alergia Pediátrica, Hospital Sant Joan de Déu, Barcelona, España.
An Pediatr (Barc). 2012 May;76(5):261-7. doi: 10.1016/j.anpedi.2011.11.006. Epub 2012 Jan 11.
Selective IgA deficiency is the most common Primary Immune Deficiency. Only a small proportion of these patients present during childhood, but this proportion increases over the years, and may be associated with an IgG subclass deficiency with increased susceptibility to respiratory and digestive tract infections. During childhood, IgA deficient patients may also refer to symptoms related to allergic and autoimmune diseases or tumours.
To describe the relationship of selective IgA deficiency with infections, allergic diseases, autoimmune disorders and tumours. To investigate the presence of other immune disorders associated with selective IgA deficiency. To suggest a follow-up protocol for these patients.
Retrospective study of paediatric patients (<18 years) being followed-up in the Clinical Immunology Department between 1992 and 2007, as well as laboratory records with IgA values below 50mg/L. Clinical records were reviewed (frequency and intensity of diseases associated with selective IgA deficiency) along with immunology tests performed.
A total of 330 paediatric patients were identified with a selective IgA deficiency: 39 (11.8%) suffered from recurrent ear infections (2 developed secondary deafness), 58 (17.5%) from recurrent upper respiratory tract infections, and 20 patients (6%) from recurrent pneumonia, 6 of whom developed secondary bronchiectasis and 2 underwent a lobectomy. A relationship with atopic disease was found in 62 (18.78%) of patients. Regarding digestive disorders, chronic diarrhoea was found in 21 (6.5%), coeliac disease in 22 (6.6%), and persistently high plasma transaminases in 3. Autoimmune manifestations were found in 38 (11.5%), juvenile chronic arthritis, type 1 diabetes, vitiligo, cytopenia, and Crohn's disease, amongst others). Tumours were identified in 5 (1.5%). An IgG sub-class deficiency was found in 5 patients (4%), and 6 patients had a confirmed deficiency in antibody production.
In our cohort, 56.6% of patients with IgA deficiency showed other comorbidities which were, in decreasing frequency: recurrent infections (respiratory and ear infections), allergic diseases, autoimmunity and tumours. Some patients will develop a more severe humoral defect (IgG subclass deficiency with or without antibody deficiency).
选择性IgA缺乏是最常见的原发性免疫缺陷病。这些患者中只有一小部分在儿童期发病，但这一比例多年来呈上升趋势，且可能与IgG亚类缺乏有关，导致呼吸道和消化道感染易感性增加。在儿童期，IgA缺乏的患者也可能出现与过敏性和自身免疫性疾病或肿瘤相关的症状。
描述选择性IgA缺乏与感染、过敏性疾病、自身免疫性疾病和肿瘤的关系。调查与选择性IgA缺乏相关的其他免疫紊乱情况。为这些患者提出随访方案。
对1992年至2007年间在临床免疫科接受随访的18岁以下儿科患者以及IgA值低于50mg/L的实验室记录进行回顾性研究。回顾临床记录（与选择性IgA缺乏相关疾病的频率和严重程度）以及所进行的免疫学检查。
共确定330例患有选择性IgA缺乏的儿科患者：39例（11.8%）患有复发性耳部感染（2例继发耳聋），58例（17.5%）患有复发性上呼吸道感染，20例（6%）患有复发性肺炎，其中6例继发支气管扩张，2例接受了肺叶切除术。62例（18.78%）患者与特应性疾病有关。在消化系统疾病方面，21例（6.5%）出现慢性腹泻，22例（6.6%）患有乳糜泻，3例血浆转氨酶持续升高。38例（11.5%）出现自身免疫表现（包括青少年慢性关节炎、1型糖尿病、白癜风、血细胞减少症和克罗恩病等）。5例（1.5%）发现肿瘤。5例（4%）发现IgG亚类缺乏，6例确诊抗体产生缺陷。
在我们的队列中，56.6%的IgA缺乏患者还患有其他合并症，按频率递减依次为：复发性感染（呼吸道和耳部感染）、过敏性疾病、自身免疫性疾病和肿瘤。一些患者会出现更严重的体液缺陷（伴有或不伴有抗体缺乏的IgG亚类缺乏）。
