ANTINUCLEAR ANTIBODIES IN EARLY-ONSET PAUCIARTICULAR JUVENILE CHRONICARTHRITIS (JCA) ARE ASSOCIATED WITH HLA-DQB1-ASTERISK-0603 - A POSSIBLE JCA-ASSOCIATED HUMAN-LEUKOCYTE ANTIGEN HAPLOTYPE

A panel of 43 early onset pauciarticular (EOPA) juvenile chronic arthr itis (JCA) patients have been typed for human leucocyte antigens (HLA) DRB1, DPB1, DQA1 alleles, and DQB10603 status using molecular-based methods. Increased frequencies of DRB108 [odds ratio (OR) 7.7, 95% co nfidence Interval (CI) 2.6-22.3], DRB111 (OR 3.1, 95% CI 1.2-8.1), DR B11301 (OR 7.7, 95% CI 2.6-22.3), DPB1*0201 (OR 3.5, 95% CI 1.6-8.0), DQA10103 (OR 4.4, 95% CI 1.5-13.3), DQA1*0501 (OR 2.9, 95% CI 1.3-6. 6), DQA10601 (OR 30, 95% CI 3.6-241) and DQB1*0603 (OR 7.3, 95% CI 3. 0-17.6) were found in the EOPA-JCA group compared with Caucasoid contr ols. Stratification of the EOPA-JCA group into antinuclear antibody (A NA) positive (n = 18) and ANA negative (n = 25) individuals revealed t hat ANA positivity was only associated with DRB11301 (OR 4.2, 95% CI 1.0-17.3), DPB10201 (OR 4.0, 95% CI 1.0-15.7) and DQB1*0603 (OR 11.5, 95% CI 2.5-53.4). Further analysis of the relative contributions of H LA antigens to ANA status revealed that DQB10603 determined the prima ry HLA effect. No apparent interaction between DQB10603 and DRB1*1301 or between DQB10603 and DPB1*0201 was found to contribute to the ass ociation with ANA. We suggest that those ANA positive individuals with a restricted HLA background, (DQB10603 positive), defines a group of EOPA-JCA patients which will be especially valuable in the characteri zation of the ANA associated with EOPA-JCA.