Objectives/Aims: We investigated the incidence of immunoglobulin A (IgA) deficiency in Chinese population.
Background: The frequency of IgA deficiency, defined as a serum IgA level of <0·05 mg dL−1, has been broadly studied in different ethnic groups. Individuals with IgA deficiency may form specific antibodies against IgA, which can cause an anaphylactic response when the patient receives an IgA‐containing blood transfusion.
Methods: A sandwich enzyme‐linked immunosorbent assay was performed to screen for IgA deficiency and particle gel immunoassay used for confirmation. IgA antibodies were further detected by the DiaMed anti‐IgA test in IgA‐deficient blood donors.
Results: Of the total 22 609 healthy blood donors screened, only seven cases were confirmed as having IgA deficiency (<0·05 mg dL−1). Another seven cases displayed relative IgA deficiencies, with mean IgA concentrations ranging from 0·39 to 3·70 mg dL−1. Anti‐IgA was identified in 2 of the 14 IgA‐deficient blood donors whose IgA levels were <5 mg dL−1. Estimation of the theoretical risk for IgA anaphylactic transfusion reaction was 0·009%.
Conclusion: The prevalence of IgA deficiency in Chinese is low. However, potential risks exist in performing blood transfusion to IgA‐deficient persons, and measures should be taken to reduce IgA anaphylaxis.