HLA and IgA deficiency in blood donors.

We have identified 67 IgA deficient healthy blood donors in our region by systematic screening of 24,782 blood samples. HLA typing results on 36 of these donors indicated a significant association with both HLA-A1 and HLA-B14 antigens. The frequency of A29 and B8 antigens was also increased. However, B8 association may be secondarily involved due to linkage disequilibrium (e.g., A1-B8-DR3). The frequency of HLA-A1 and HLA-B8 antigens was increased in the group of IgA deficient donors who developed anti-IgA antibodies (53.9%) compared to those who did not (26.1%). Although the sample size appears to be too small to show a statistical significance (chi 2 = 2.76, 0.05 less than p less than 0.1), this is the first report to imply a possible HLA association with anti-IgA antibody formation by IgA deficient healthy individuals.