HLA-DRB1, DQA1, AND DQB1 GENOTYPES AND RISK OF VASCULITIS IN PATIENTSWITH RHEUMATOID-ARTHRITIS

Objective. To investigate the association of rheumatoid vasculitis (RV ) with the expression of the shared epitope, HLA-DRB104, DQA1, and DQ B1 alleles. Methods. A case-control study was designed to compare the frequency of thr shared epitope, DRB104 alleles, DQA1, and DQB1 allel es of 31 patients with RV with that of 76 patients with rheumatoid art hritis (RA) without vasculitis. RV cases were discerned in subgroups a ccording to presence or absence of minor skin vasculitis and major org an lesions, HLA-DRB1, DQA1, and DQB1 typing was performed by a polymer ase chain reaction amplification and oligonucleotide hybridization, Re sults. Overall, no associations were found between RV and the shared e pitope, the DRB104 alleles, DQA1, or DQB1 alleles. The risk of develo ping RV with minor Skin vasculitis (i.e., purpura or petechiae) was 10 -20-fold increased in patients with DRB104, in particular in those ho mozygous for DRB104, and also in those with DRB1*0401. No such associ ation was found for patients with major organ lesions, Conclusion. The occurrence of vasculitis in RA is not associated with The shared epit ope. DQA1, or DQB1 alleles. However the risk of minor skin vasculitis is higher in patients carrying. DRB104.