This article reviews the reproductive immunology of men with particula
r emphasis on the mechanisms that prevent immunities to spermatozoa, t
he pathogenesis of autoimmunity to sperm, and mechanisms of infertilit
y due to sperm antigens. Alterations in sperm function at the level of
sperm transport within the female reproductive tract, capacitation an
d the acrosome reaction, and sperm-egg interactions are discussed.