Serum antibody levels against T mycoplasmas in two North American Indian populations predisposed to spondylitis.

Serum antibody levels against T mycoplasmas (Ureaplasma urealyticum) were determined by the metabolic inhibition method in several populations. A higher prevalence of antibody was found in Haida Indians and Bella Coola Indians than in blood donors, patients with rheumatoid arthritis, and patients attending a VD clinic. Antibody levels did not correlate with the presence of spodylitis or the histocompatibility antigen HLA-B27, although both these Indian populations have a high prevalence of spondylitis and HLA-B27.