HLA and sarcoidosis in the Japanese.

One hundred fourteen patients with sarcoidosis, who were diagnosed as having sarcoidosis histologically, have been typed for HLA class 1 (A, B, and C) and class 2 (DR and DQ) antigens. Controls consisted of 478 healthy Japanese subjects. The frequencies of HLA-A1, HLA-Bw46, HLA-Cx46, HLA-DRw8, HLA-DRw9, and HLA-DRw52 were significantly increased in sarcoidosis compared to control subjects, but only four patients were positive for HLA-A1. Increased frequencies of HLA-Bw46 and HLA-Cx46 were thought to be attributable to linkage disequilibrium with HLA-DRw8. Patients with HLA-DRw52 were the most frequent (84 cases of 113). No significant differences were observed between HLA-DRw52-positive and HLA-DRw52-negative patients in their clinical features, but all of the patients with muscular involvement (six cases) were positive for HLA-DRw52. Among patients positive for HLA-DRw52, those with HLA-DR5 showed a significantly better clinical course and earlier onset of the disease than those with HLA-DRw8. These results suggest that HLA antigens may play an important role in the pathogenesis of sarcoidosis.