Deposits of complement components can be detected in normal placentae and are usually localized in the fibrinoid areas of the decidua and on the walls of the placental and fetal stem vessels in the absence of immunoglobulins. A marked increase of these deposits is observed in the placentae of patients with preeclampsia. Numerous studies failed to reveal the presence of complement components on the surface of trophoblast. Conversely, the cells of this extraembryonic membrane express complement regulatory proteins, which include CD46, CD55, and CD59. The role of these proteins is to protect trophoblast from complement attack. However, the protective effect of the complement regulators can to some extent be overcome by the action of complement-fixing antibodies to trophoblast, which can be detected in the sera of patients with repeated spontaneous abortions. Spermatazoa are susceptible to the cytotoxic effect of complement present both in the male and the female reproductive tracts. Recently published data provide evidence for an important role of complement in promoting fertilization.
|Number of pages||6|
|Publication status||Published - 1995|
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