Evidence that Chlamydia trachomatis causes seronegative arthritis in women

Chlamydia trachomatis elementary bodies (EBs) were found in synovial membranes or synovial fluid cell deposits from five of 15 women with seronegative mono- or oligoarthritis by means of a fluorescein conjugated anti-chlamydial monoclonal antibody (Micro Trak; Syva). Genital tract specimens were taken from only five of the patients, one of whom had intra-articular EBs, but none was chlamydia positive. Six of 10 patients tested were HLA-B27 positive, and chlamydial IgG antibody, measured by microimmunofluorescence, was present at a titre of 1/greater than or equal to 64 in the sera of five of the 15 patients, three of the five having EBs in their joints. In contrast, chlamydial EBs were not detected in the joints of a control group of 10 other women, most of whom had rheumatoid arthritis. None of them was HLA-B27 positive, and only one had a chlamydial antibody titre of 1/greater than or equal to 64. Neither Mycoplasma hominis nor ureaplasmas were isolated from the synovial fluids of seven patients and five controls who were tested. Antibody to M genitalium, however, was detected in five of the 10 patients but in none of the controls. This evidence apart, there was no other suggest that mycoplasmas or ureaplasmas might be responsible for arthritis which could not be attributed to chlamydiae.