Association of human leukocyte antigen-DRB1 alleles with disease susceptibility and severity of aplastic anemia in Korean patients.

Although association of human leukocyte antigen (HLA)-DR2 (DRB11501) with susceptibility to aplastic anemia (AA) has been well documented in several different ethnic groups, little is known about the protective role of HLA in this disease. HLA-DRB1 alleles were analyzed in 109 Korean AA patients (26 nonsevere and 83 severe) and 800 healthy controls. The frequency of DRB11501 was significantly higher in AA patients compared with controls [33.0% vs 15.3%, p=0.000004, p(c)=0.0001, odds ratio (OR)=2.74]. Nonsevere AA (30.8%, OR=2.47) and severe AA patients (33.7%, OR=2.83) showed similar changes, and DRB11501 was considered a susceptibility factor to AA in both forms of the disease. The frequency of DRB11302 in total AA patients was not different from controls (12.8% vs 17.9%), but it was significantly lower in severe AA compared with nonsevere AA patients (6.0% vs 34.6%, p=0.0006, p(c)=0.02, OR=0.12). DRB11302 was considered a protective factor against severe AA. In Koreans, DRB11501 was associated with disease susceptibility to AA and DRB1*1302 with protection against the severe form of the disease.