Serum IgG1 and IgG3 Antibodies to Chlamydia trachomatis Pgp3 and Hsp60 in Men of Subfertile Couples.

Abstract

Our goal was to investigate immunoglobulin G1 (IgG1) and immunoglobulin G3 (IgG3) antibody responses to Chlamydia trachomatis proteins Pgp3 and Hsp60 in males of subfertile couples and to explore the association of these antibodies with semen parameters and male factor infertility. Serum samples were collected from 256 male partners of subfertile couples. Serum IgG1 and IgG3 antibodies to C trachomatis Pgp3 and Hsp60 were measured using enzyme immunoassays. Semen samples were analyzed for volume, sperm concentration, and motility according to World Health Organization criteria. Altogether, 74 (29.8%) men were seropositive to either C trachomatis Pgp3 IgG1 or IgG3, and 67 (27.0%) to either Hsp60 IgG1 or IgG3. Chlamydia trachomatis Pgp3 IgG1 and IgG3 antibodies were associated with impaired sperm motility (asthenozoospermia) (18.6% vs 6.3%, P = .006 for Pgp3 IgG1; and 21.4% vs 8.0%, P = .03 for Pgp3 IgG3). After adjusting for smoking, alcohol risk consumption, and body mass index, the association between serum C trachomatis Pgp3 IgG1 seropositivity and asthenozoospermia remained statistically significant (odds ratio, 3.0 [95% confidence interval, 1.12-8.01]; P = .03). The presence of Hsp60 IgG1 antibody was associated with a higher teratozoospermia index (1.47 ± 0.15 vs 1.39 ± 0.16; P = .001). Our results suggest that prior Chlamydia trachomatis infection, as indicated by Pgp3 seropositivity, may negatively impact male fertility potential by affecting sperm motility and morphology.