Immunoblot Analysis of Antibody Response to Chlamydia trachomatis in Patients with Reactive Arthritis and Ankylosing Spondylitis

Abstract

Antibodies to Chlamydia trachomatis were found in 60% of patients with reactive arthritis (ReA) and 33% of patients with ankylosing spondylitis (AS), compared with 19% of healthy blood donors. The IgG, IgA and IgM immune responses in patients with ReA and AS were further analysed by immunoblotting. Most patients had IgG antibodies to a large number of C. trachomatis antigens. IgA (and especially IgM) antibodies were less prevalent. Differences in the antibody response to individual antigens were seen between the two groups of patients, with respect to both IgG and IgA. Especially evident was the high prevalence of IgA antibodies to a 60 kD antigen among patients with ReA (67 %) compared with patients with AS (20%).

Key Words:

• C. trachomatis
• reactive arthritis
• ankylosing spondylitis
• antibody response
• immunoblot