Résumé
Objective. To determine whether the HLA‐DMA and DMB genes, whose encoded molecules are involved in HLA class II‐restricted antigen presentation, contribute to the genetic susceptibility to rheumatoid arthritis (RA). Methods. One hundred ninety‐one RA patients, 147 control subjects, and 218 HLA‐DRBI genotypematched control subjects were oligotyped for DMA and DMB genes. Results. DMA*0103 and DMB*0104 were significantly increased in the RA patients compared with the randomly selected and the matched controls, thus indicating a direct influence of the DM genes. After stratification of the patients and matched controls according to DRB1 genotypes, only DMA*0103 was increased in the RA patients with DRB1*01, as well as in the patients negative for the RA‐susceptibility DR alleles. Conclusion. Our results suggest that DMA*0103 could play an additional role in the genetic susceptibility to RA.