The frequency of HLA class I alleles in Japanese patients with bone marrow failure.

The frequencies of the HLA-B*4002 and HLA-A*0206 alleles in patients with aplastic anemia (AA) (n=32; 21.9%) and paroxysmal nocturanl hemoglobinuria (PNH) (n=24; 22.9%), respectively, were significantly different from those in controls (n=371; 8.6%, p<0.002 and 7.7%, p<0.001, respectively), suggesting that each specific allele in AA or PNH may be related to the immunologic pathophysiology of these disorders.