Evaluation of immunofluorescence on pig zona pellucida for detection of anti-zona antibodies in human sera

Using immunofluorescence tests, antibodies reacting with pig zona pellucida could be detected in 31% of 103 sera from patients in different clinically defined categories, mainly fertile males and females and patients from couples with unexplained infertility. The antibodies could in all cases be absorbed by means of pig erythrocytes — in most sera with all erythrocyte suspensions tested, but in some cases only with erythrocytes from certain animals — indicating that antibodies both to generally occurring pig antigens and alloantigens may be present in human sera. Staining of pig zonae was recorded equally frequently with unabsorbed sera from infertile and fertile males and females, respectively, but titres of 1 : 16 or more occurred more frequently among infertile than among fertile females (P = 0.053).