HLA-A, B, Cw and DRB1, DRB3/4/5, DQB1, DPB1 frequencies in German immunoglobulin A-deficient individuals

HLA class I and II frequencies and haplotype frequencies were determined in 80 German immunoglobulin (Ig)A-deficient individuals and 157 healthy contr ols with normal IgA levels using serological and DNA typing methods. For se veral alleles, significant associations were found, which could be explaine d mainly in the context of a positive association with three different exte nded haplotypes (HLA-B*08:DRB1*0301: DQB1*0201, HLA-B*14:DRB1*0102:DQB1*050 1 and HLA-B*44:DRB1*0701:DQB1*0202) and a negative association with a fourt h haplotype (HLA-B*07:DRB1*1501:DQB1*0602). Furthermore, for the first time this study reports a positive association of IgA deficiency with DPB1 alle les. Homozygosity rate for the gene loci DRB1 and DQB1 was increased in IgA deficiency. Further analysis suggested a different pattern of HLA associat ions depending on the degree of IgA deficiency and the gender of the IgA-de ficient individuals.