Sperm Agglutinins in Human Semen and Blood

SummaryThe presence of sperm agglutinins in the seminal plasma and blood serum of 2 sterile men whose spermatozoa agglutinate in the ejaculate is reported. The sera have antibody titers of 1:80 and 1:20, respectively. Head, tail, and mixed varieties of agglutination are seen in the early stages, but tail agglutination predominates in the larger clumps. Agglutination occurs only in the presence of motile spermatozoa and none is seen in the fresh ejaculate until liquefaction begins and active sperm movement develops. Temperature influences agglutination by its effect on sperm motility. The motility of the clumped spermatozoa is impaired with consequent loss of the ability to penetrate cervical mucus. The clumps can be completely dispersed by mechanical agitation after which the spermatozoa reagglutinate although not quite to the original extent. Complement inactivation does not influence agglutination. The antibody can be removed by absorption.