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<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<0.01) and with the presence of RF (p<0.05) and hidden RF (p<0.05). In the whites, HLA-DR5 (p<0.05) and DRW8 (p<0.001) were associated with pauciarticular onset and early onset pauciarticular patients. HLA-DRW8 was also associated with white JA patients with iridocyclitis (p<0.001) and black (p<0.01) and white patients (p<0.001) with the presence of ANA. HLA-MT2 was demonstrated in all 24 black patients (p<0.001) and in 54/80 white patients (p<0.001). HLA-MT2 was associated with black (p<0.01) and white (p<0.001) patients with early onset pauciarticular disease and the presence of iridocyclitis in white patients (p<0.001). The association of HLA antigens in black JA patients has not been reported before.