Possible immunological basis for recurrent spontaneous abortions: a review.

BACKGROUND: In normal pregnancy, the pregnant mother paradoxically tolerates the semi-allogeneic foetus until term. Experimental and clinical data to explain such tolerance in man reflects the involvement of multiple mechanisms. OBJECTIVE: To review the data pertaining to the experimental and clinical efforts to explain why the mother immunologically tolerates a semi-allogeneic pregnancy to term. DESIGN, SETTING AND METHODS: A review of the literature on state of the art thinking among researchers and clinicians on recurrent spontaneous abortions is summarised. RESULTS: A large body of recently published data strongly suggest that a breakdown in immunological maternal-foetal interactions may lead to occasional or recurrent foetal loss. Immunoregulatory activities involving blocking antibodies, regulatory factors, immunological cells, hormones, structural proteins and cytokines constitute the pregnancy-sustaining network. CONCLUSION: The majority of the evidence reviewed points to the involvement of immunological factors in successful pregnancies. However, the underlying mechanisms are inadequately explained, are largely speculative and require more focused investigation. A complete understanding of the mechanisms involved would enhance our capacity to develop rational ways of addressing recurrent pregnancy losses.

Purification and partial characterisation of goat placental IgG: A possible model for the study of human maternal-foetal interaction.

Viviparous pregnancy in vertebrates is a major immunological puzzle. Ideally the maternal immune system should reject the foetus, which is antigenically different by virtue of its compliment of paternal genes and proteins. Instead the mother accommodates the foetus until term. This is partly thought to result from production of blocking antibodies, down regulation of the maternal immune responses and existence of a placental barrier among others. This report presents findings that antibodiess exist on goat placentae that could hypothetically block rejection of the fetal allograft. The total obtainable placental IgG was approximately 110Ug per term placenta. Analysis of eluate antibodies by SDS PAGE showed that placental IgG is approximately 214.4kDa and had a pI of 6.02. Trypsin digestion of acidified plantal microvesicles led to release of a 53kDa peptide similar to one reported earlier in humans. This observation suggest that certain placental proteins may be conserved across the mammalian species for reproductive purposes. We propose that goat placental IgG may be useful as a model for the study of maternal-foetal interaction during pregnancy.

Purification and Partial Characterization of Goat Placenta IgG : a Possible Model for the Study of Human Maternal-Foetal Interaction

Viviparous pregnancy in vertebrates is a major immunological puzzle. Ideally the maternal immune system should reject the foetus; which is antigenically different by virtue of its compliment of paternal genes and proteins. Instead the mother accommodates the foetus until term. This is partly thought to result from production of blocking antibodies; down regulation of the maternal immune responses and existence of a placental barrier among others. This report presents findings that antibodiess exist on goat placentae that could hypothetically block rejection of the fetal allograft. The total obtainable placental IgG was approximately 110Ug per term placenta. Analysis of eluate antibodies by SDS PAGE showed that placental IgG is approximately 214.4kDa and had a pI of 6.02. Trypsin digestion of acidified plantal microvesicles led to release of a 53kDa peptide similar to one reported earlier in humans. This observation suggest that certain placental proteins may be conserved across the mammalian species for reproductive purposes. We propose that goat placental IgG may be useful as a model for the study of maternal-foetal interaction during pregnancy