Accelerated expression of Ca antigen by placental villous trophoblast in pre-eclampsia

The Ca antigen is expressed by a range of normal tissues, as well as by many malignant neoplasms. The former includes placental villous syncytiotrophoblast where it appears first on syncytial sprouts at 20 weeks gestation, and progressively becomes more intensely and widely expressed on the surface of the trophoblast of villi of all sizes. We report here the prematurely intense expression of the antigen in pre-eclampsia (22 cases), by comparison with control sections from uncomplicated pregnancies. The expression of this antigen may have value as a relatively objective marker of accelerated maturation of the placental villous tree. It is suggested that the premature expression of Ca antigen in villous trophoblast in pre-eclampsia is due to external modification of a temporally related gene activation.