Lack of association between DQ A and DX A polymorphisms with rheumatoid arthritis and Felty's syndrome.

DQ A and DX A RFLPs were studied in DR4-positive rheumatoid arthritis, Felty's syndrome, and in DR4-positive control subjects, and in the light of the previously documented association between Felty's syndrome and the DQ B 3.1 allele (3b RFLP). In these DR4-positive subjects there were no preferential associations between DQ A or DX A polymorphisms and rheumatoid arthritis or Felty's syndrome and no evidence for unusual DQ A-B haplotypic associations in Felty's or rheumatoid subjects.