Humoral immune response to an allogenic foetus in normal fertile women and recurrent aborters

BACKGROUND: Several humoral immune factors are responsible for a successful pregnancy. There are a few studies, which demonstrate the role of antipaternal cytotoxic antibodies (APCA) and mixed lymphocyte reaction blocking factor (MLR-Bf) in the maintenance of pregnancy. However, these factors have not been studied in women with history of recurrent spontaneous abortion (RSA). We designed this study to review the role of APCA and MLR-Bf in normal pregnancy as well as in women with a history of RSA. METHODS: One hundred and five women with unexplained recurrent spontaneous abortion were included in the present study. These women were screened for all other known causes of recurrent abortion. We also included 60 normal fertile women, fifteen from each trimester and fifteen women during the post partum period (up to six months). RSA and controls (normal pregnancy) were matched for age, caste, and socio economic background and also for parity. APCA and MLR-Bf were evaluated in all the groups. All women with RSA who conceived during the study period were on follow up. RESULTS: We have analyzed the status of APCA and MLR-Bf in normal pregnancy (different gestational periods and during post partum), and in women with history of RSA. Our results show that APCA was significantly higher in controls as compared to RSA women. MLR-Bf was directed against the husbands' cells in normal pregnancy and was virtually absent in RSA women. CONCLUSION: Our results indicate that there is a significantly low titer of APCA and MLR-Bf in women with recurrent spontaneous abortion. This highlights the role of these factors in the maintenance of successful pregnancy.