Selective immunoglobulin A deficiency (SIgAD) primarily leads to recurrent infections and autoimmune diseases: A retrospective study of Chinese patients in the past 40 years

Selective immunoglobulin A deficiency (SIgAD) is considered to be the most common human primary immune-deficiency disease in the world. However, the incidence in China is obviously lower than Caucasian races. The definition of SIgAD has changed over time with the progress of people's understanding. The scientific community did not reach a consensus on the definition until 1999. As a result, many previously reported cases need to be excluded under the current definition. SIgAD can lead to several spectra of diseases including infections and autoimmune diseases. We retrospectively summarized the SIgAD patients in Peking Union Medical College Hospital (PUMCH), and summarized the Chinese SIgAD reported in China and abroad in past 40 years. Fourty three SIgAD patients were confirmed in the study, in which 9 were healthy without clinical symptoms. Of the 34 patients with clinical symptoms, recurrent infections were found in 29 (85.3%) patients; 13 (38.2%) patients were with autoimmune diseases; 6 (17.6%)cases had allergic symptoms; 3 patients (8.8%) were with tumors, only one case (2.9%) had a family history. Compared with other countries, sIgAD patients in China showed similar symptoms, but the rate of recurrent infections and autoimmune diseases were higher than some other countries; most of the allergic symptoms are drug allergy, different with the allergic sequelae reported in other countries, such as asthma, rhinitis, food allergy and atopic dermatitis; and it is rare to have family history in Chinese patients. We also figured out that more female SIgAD patients tend to have more autoimmune diseases than men (P = 0.039).