HLA antigens in Yugoslav population with rheumatoid arthritis.

The antigens of HLA-DR locus were determined in 127 patients with rheumatoid arthritis and in 175 healthy persons. The frequency of HLA-DR1 antigen was discovered in 45% of the patients and in 22.3% of the examinees from the control group (p less than 0.001). The relative risk is 2.84. 69% of the patients were seropositive. The HLA-DR4 antigen was found in 34% of the patients and in 21% of the healthy examinees (p less than 0.05). The relative risk is 1.91. The rheumatoid factor was determined in 70% of the patients with this antigen.