HLA-DR4 in Negro and Mexican rheumatoid arthritis patients

We tested HLA-DR antigens in 38 Caucasian, 18 Negro, 17 Mexican, and 5 Japanese patients with rheumatoid arthritis. Significantly high HLA-DR4 frequencies were observed in all races; 61% in Caucasians, 39% in Negroes, 77% in Mexicans, and 100% in Japanese. However, no clinical correlation with DR4 was found in these patients.