title: The frequency of rheumatoid arthritis among relatives of probands with definite ankylosing spondylitis.
abstract: We studied families of 23 unrelated HLA-B27 positive probands with definite ankylosing spondylitis to investigate the occurrence of rheumatoid arthritis. The prevalence of RA among these relatives was significant higher (2.91%; 0.02 less than p less than 0.05) than in the control group of 28 healthy individuals (1.02%). These data suggest an increased relative risk of RA in relatives of patients with AS.
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000235:genetics*; D005260:Female; D006680:HLA Antigens; D015796:HLA-B27 Antigen; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D013167:Spondylitis, Ankylosing / Q000235:genetics* / Q000276:immunology
chemical_list: D006680:HLA Antigens; D015796:HLA-B27 Antigen