Immunity to zona pellucida

In the mid-1970s, animal studies revealed that the zona pellucida (zp) contains several organ-specific glycoproteins (now known as ZP1, ZP2 and ZP3) and that antibodies to these antigens were capable of blocking fertilization in vitro. Human and porcine zp antigens showed cross-reactivity, and interest in this antigen-antibody system was therefore stimulated in 1977 when a high percentage of sera from infertile women by immunofluorescence was found to stain porcine zonae. However, when similar reactivities were subsequently observed, also with sera from fertile females and even with male sera, the specificity of the reactions had to be questioned, and when absorption with pig and human erythrocytes was found to remove the reactivity of most of the sera, serious doubt was raised concerning the presence and clinical significance of zona-specific antibodies. After 20 years and numerous studies there is still no convincing evidence for the occurrence of true zona-specific autoantibodies as the cause of human infertility.

In one of the best controlled studies, with a passive hemagglutination technique using purified porcine zona material for coating of the erythrocytes, weakly positive reactions were recorded in 5.6% of 320 women with unexplained infertility, in 1.7% of 1552 women with infertility of known cause, in 1.5% of 193 fertile women, but in none of 292 men.

In several animal species (dog, rabbit, horse and monkey) active immunization with porcine zona has, on the other hand, produced long-term infertility. The immunization usually also leads to abnormalities in ovarian structure and function with disruption of folliculogenesis and changes in menstrual cycle, and in veterinary medicine immunization with pig zona material is now used to sterilize bitches.

Pregnancy Guide

Pregnancy Guide

A Beginner's Guide to Healthy Pregnancy. If you suspect, or know, that you are pregnant, we ho pe you have already visited your doctor. Presuming that you have confirmed your suspicions and that this is your first child, or that you wish to take better care of yourself d uring pregnancy than you did during your other pregnancies; you have come to the right place.

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