Autoantibodies to zona pellucida: a possible cause for infertility in women.

Human and pig ovaries were tested by agar gel diffusion and found to contain several cross-reacting (common) antigens. At least one common antigen was located in the zona pellucida as determined by indirect immunofluorescence. Serum samples from 22 infertile women were tested on pig eggs by immunofluorescence, and six of these samples produced strong and nine produced moderate reactions with the zona pellucida. The autoantibodies may be responsible for infertility in these women.