A new method for measurement of cytotoxic antibodies to human spermatozoa.

The energy producing reactions of spermatozoa will cease after the spermatozoa have been damaged by a complement-mediated antibody reaction and, consequently, their ATP content falls rapidly. The finding was applied and used for determination of the cytotoxic reaction caused by sperm antibodies. This reaction could be recorded by comparing the difference in ATP content between damaged and control spermatozoa after 2 hr incubation. A serum dilution that still reduced the ATP content by 50% or more was regarded to be cytotoxic. Only those sera, collected from infertile patients, with an agglutinating titer of at lease 1:64 and an immobilizing titer of 1:4 were cytotoxic to spermatozoa. The method proved to be both simple and more sensitive than the supraviatal staining technique as a cytotoxicity test.