COMPOUND HETEROZYGOSITY OF HLA-DR4 AND DR1 ANTIGENS IN ASIAN INDIANS INCREASES THE RISK OF EXTRAARTICULAR FEATURES IN RHEUMATOID-ARTHRITIS

The relationship of HLA-DR antigens in rheumatoid arthritis (RA) patie nts with the presence of rheumatoid factor (RF), extra-articular featu res, joint erosions, functional status and response to disease modifyi ng anti-rheumatic drugs (DMARDs) was studied. Seventy-four patients wi th RA were serologically typed for class II antigens. Clinical feature s were recorded before starting DMARDs and during follow-up to assess response and side-effects. HLA-DR1 and DR4 antigens were present more frequently in patients with RA than in the general population. The pre sence of DR4 correlated with RF seropositivity (P < 0.001) while DR1 w as associated with seronegativity (P < 0.02). Ten of the 11 patients w ith extra-articular features had DR1 and/or DR4. Patients with both DR 4 and DR1 had a significantly higher frequency of extra-articular feat ures compared with those with only one of these (P < 0.01). HLA-DR4 an d DR1 had no relation with the presence of subcutaneous nodules, erosi ve changes, deformities, response to drugs and side-effects of DMARDs.