Specific IgG and IgA antibodies to Chlamydia trachomatis in infertile women.

IgG, IgA, and IgM antibody titers to Chlamydia trachomatis were determined in sera of 80 infertile women and 100 controls by a single antigen (L-2) immunoperoxidase assay. The infertile women included 50 with unexplained infertility and normal hysterosalpingogram (HSG) and 30 with abnormal HSG. The control sera included 50 from primiparous and 50 from multiparous women. The prevalence of C. trachomatis IgG antibody was significantly higher in infertile women with abnormal HSG as compared with infertile patients with normal HSG and controls (87% v. 20% and 10%, respectively). The geometric mean titer (GMT) of C. trachomatis IgG antibodies of infertile women with abnormal HSG was significantly higher than those of controls (20.7 v. 5.6). A significantly higher prevalence of C. trachomatis IgA antibodies was found in infertile women with both abnormal and normal HSG than in controls (77% and 14% v. 3% respectively). No C. trachomatis IgM antibodies (less than 2) were found in any of the infertile or control groups. The possibility that serum C. trachomatis IgA antibodies may serve as a marker for early recognition of persistent C. trachomatis is discussed.