Inhibition of human seminal fluid DNA polymerase by an IgG fraction of seminal plasma from vasectomized men.

Immunoglobulin G (IgG) was isolated from ejaculates of intact and vasectomized men by precipitation with ammonium sulphate and DEAE-cellulose ionexchange chromatography. Velocity centrifugation revealed that all of the IgG from intact males was 7S protein while less than 40% of the seminal IgG of vasectomized men cosedimented with the 7S marker; the remaining, immunologically unidentifiable, protein was considerably smaller and heterogeneous in size. Only the 7S IgG from the post-vasectomy ejaculates inhibited the activity of a DNA polymerase from the seminal fluid of an intact male. These results suggest that formation of antibody reactive with the seminal fluid DNA polymerase is one manifestation of a vasectomy-associated autoimmune response in man.