Increased frequency of autoantibodies in men with sperm antibodies.

Autoantibodies to thyroid microsomes were more frequent in 102 infertile men with complement-dependent sperm-immobilizing activity (sperm immobilization test [SIT] ) in serum (11.8%) than in a control group of 277 men of comparable ages and semen quality without sperm antibodies (4.3%, P less than 0.05). Frequencies of organ-specific antibodies (antigastric parietal cell, antithyroglobulin, and antithyroid microsome) in 57 men with genital tract obstructions and positive SIT were similar to those for control subjects, and there were no significant differences in the frequencies of non-organ-specific autoantibodies (antinuclear antibody, rheumatoid factor, antimitochondrial, and anti-smooth muscle) in the three groups. Because in men without genital tract obstruction antithyroid microsomal autoantibodies were more common with sperm antibodies than without, the possibility of a genetic factor in the causation of sperm autoimmunity should be considered.