HLA antigens in black and white patients with juvenile arthritis: associations with rheumatoid factor, hidden rheumatoid factor, antinuclear antibodies, and immune complex levels.

HLA typing for -A, -B, -C, -DR, and -MT antigens and simultaneous studies for the presence of 19S IgM rheumatoid factor (RF), hidden 19S IgM RF, antinuclear antibodies (ANA), and immune complexes (IC) were performed on 24 black and 80 white patients with juvenile arthritis (JA) of different onset types. HLA-DRW6 (p less than 0.05) was associated with pauciarticular onset and early onset pauciarticular black patients. HLA-DR4 was found in both blacks and whites with chronic disease (p less than 0.01) and with the presence of RF (p less than 0.05) and hidden RF (p less than 0.05). In the whites, HLA-DR5 (p less than 0.05) and DRW8 (p less than 0.001) were associated with pauciarticular onset and early onset pauciarticular patients. HLA- DRW8 was also associated with white JA patients with iridocyclitis (p less than 0.001) and black (p less than 0.01) and white patients (p less than 0.001) with the presence of ANA. HLA-MT2 was demonstrated in all 24 black patients (p less than 0.001) and in 54/80 white patients (p less than 0.001). HLA-MT2 was associated with black (p less than 0.01) and white (p less than 0.001) patients with early onset pauciarticular disease and the presence of iridocyclitis in white patients (p less than 0.001). The association of HLA antigens in black JA patients has not been reported before.