Sperm-agglutinating and -immobilizing antibody formation following vasectomy prevented with dexamethasone in...

Cynomolgus monkeys (Macaca fascicularis) were treated with 1.5 mg/kg dexamethasone (DEX) before (4 to 2 days) and after (0, 2, 4, and 7 days) vasectomy. Of the four monkeys treated with DEX, only one developed sperm antibody as measured by sperm-agglutinating and sperm-immobilizing assays. All six of the vasectomized monkeys not given DEX developed both agglutinating and immobilizing sperm antibodies. In this study, DEX given before and after vasectomy blocked sperm-agglutinating and -immobilizing antibody formation. We conclude that the major antigenic exposure to sperm responsible for sperm-agglutinating and -immobilizing antibody comes at the time of vasectomy.