CLINICAL AND IMMUNOGENETIC STUDIES IN MULTICASE RHEUMATOID FAMILIES

  • 1 January 1984
    • journal article
    • research article
    • Vol. 53  (212) , 479-485
Abstract
HLA haplotypes, autoimmune diseases and circulating autoantibodies were studied in 23 families with multiple cases of rheumatoid arthritis; 76% of rheumatoid arthritis and 70% of non-rheumatoid individuals were positive for HLA-DR4. The haplotypes Bw44-Bf*S-DR4; B40-Bf*S-DR4; and B15-Bf*S-DR4 were found in 13, 9 and 7% of probands respectively and the B15-Bf*S-DR4 haplotype was found 4-5 times more frequently in DR4-positive rheumatoid arthritis than in DR4 positive, non-rheumatoid arthritis families. Rheumatoid arthritis segregated with a DR4 positive haplotype in 13 families and with a DR4 negative haplotype in 7. Analysis of HLA haplotype sharing showed greater than random sharing by affected siblings which is in keeping with genes within the MHS [major histocompatibility system] influencing susceptibility to rheumatoid arthritis. Autoimmune thyroid disorders were seen in 8% of family members investigated. They were significantly more frequent in those families in which rheumatoid arthritis segregated with a non-DR4 bearing HLA haplotype. This suggests that genes for autoimmune thyroid disease might predispose to rheumatoid arthritis independently of DR4. These genes are probably not HLA-linked, as there was no trend for HLA haplotype sharing to be increased in sibling pairs with either rheumatoid arthritis and thyroid disease or rheumatoid arthritis and thyroid antoantibodies respectively.