Autoimmunity to spermatozoa, asymptomatic Chlamydia trachomatis genital tract infection and gamma delta T lymphocytes in seminal fluid from the male partners of couples with unexplained infertility.

The relationship between an undetected, asymptomatic Chlamydia trachomatis genital tract infection, the concentration of gamma delta and alpha b T cells in semen and sperm autoimmunity was examined in 48 male partners of couples with unexplained infertility. Immunoglobulin A (IgA) antibodies to C. trachomatis were detected in seminal fluids from 14 (29.2%) of the men. Only four of these were positive for circulating anti-chlamydial IgA, suggesting that the stimulus for antibody production was within the genital tract. In contrast, four men were positive for anti-chlamydial IgG in their semen; all were also seropositive for anti-chlamydial IgG. T lymphocytes bearing the alpha beta and gamma delta antigen receptors were present in every semen sample. Men with seminal anti-chlamydial IgA, however, had significantly (P = 0.035) elevated semen gamma delta T cell concentrations (median 3100 cells/ml) than did men lacking this antibody (median 1400 cells/ml); concentrations of alpha beta T cells were comparable in both groups. Genital tract sperm autoimmunity, as shown by antibodies bound to motile ejaculated spermatozoa, was detected in 13 (27.1%) men. The presence of these antibodies was associated with elevated concentrations of both gamma delta (median 4200 versus 700 cells/ml) and alpha beta (median 5000 versus 850 cells/ml) T cells (P = 0.0002 and 0.0001 respectively). Men with antisperm antibodies only in their serum had seminal T cell concentrations comparable with men testing negative for antisperm antibodies. Anti-chlamydial IgA was identified in semen from four of 10 men with IgA bound to their spermatozoa and in none of the men with only spermatozoa-bound IgG.(ABSTRACT TRUNCATED AT 250 WORDS)