Role of HLA-DR antigens in Japanese patients with sarcoidosis.

Fifty-three Japanese patients with sarcoidosis were tested for HLA-A,B,C, DR, and DQ antigens in order to investigate immunogenetic mechanisms in the pathogenesis of sarcoidosis. All of the patients had abnormal shadows on their chest radiographs, and all had histologically confirmed sarcoidosis. Groups of 60 and 57 unrelated Japanese served as control subjects for HLA-A,B,C and HLA-D region antigens, respectively. The frequency of HLA-DRw52 was 79.2% (42 of 53) in the patient group compared with 50.9% (29 of 57) in the control group, and the difference was significant (chi 2 = 9.66, p less than 0.005, pc less than 0.05, relative risk = 3.69). On the other hand, no significant association was found with HLA-A,B,C antigens. When various clinical features of the patients were taken into account, there was a tendency for the frequency of DRw52 to be lower in the patients who were in an advanced stage or who had resisted treatment with steroids. Furthermore, 31 of the 32 patients without ophthalmic involvement were DRw52-positive, which was highly significant (96.9% as compared with 50.9% of the control group; chi 2 = 19.74, p less than 0.001, pc less than 0.01, relative risk = 29.93), whereas the frequency of DRw52 in the patients with ophthalmic involvement was almost the same as in the control group. These results suggest that HLA-DR antigens play a significant role in the pathogenesis of sarcoidosis, and there may be a heterogeneity in the clinical entity of sarcoidosis.