Chlamydia trachomatis antibody detection and diagnosis of reactive arthritis.

Objective: To investigate whether determining the presence of serum or synovial fluid (SF) IgG and IgA of anti-Chlamydia antibodies with two recent commercially available enzyme-linked immunosorbent assays (ELISA) using synthetic peptides or recombinant antigen could be helpful to detect possible Chlamydia trachomatis (CT)-involved disease in rheumatological patients without evidence of urogenital CT infection.

Methods: The prevalence of such antibodies was determined in samples from patients with well-defined disease, i.e. CT sexually acquired arthritis and from patients with other inflammatory arthropathies unrelated to CT.

Results: When considering IgG and/or IgA anti-MOMP or anti-LPS antibodies, a sensitivity of 100% was obtained for serum and SF samples, but with a low specificity. A sensitivity and a specificity equal or close to 80% were observed for the SF IgG anti-MOMP antibodies.

Conclusion: Clinically, the most appropriate determination was the SF IgG anti-MOMP antibodies. This commercially available ELISA test could be useful for the diagnosis of probable CT reactive arthritis.