Complement system in abnormal pregnancy and chorionic neoplasia: immunotherapy and chemotherapy of chorionic neoplasia.

In normal pregnancy, the activity of the alternate pathway elevates latently and compensatorily for the suppression of cellular immunity. Aging of the placenta becomes a trigger for the onset of labor and production of C3-a. In cases of hydatidiform mole, abruptio placentae, threatened abortion, and chorionic malignancy, the activity of the complement system is depressed, especially that of C3-activator and alternate pathway. This may in turn result from activation of complement by the pathologic lesion of the chorionic villi. In pathologic lesions of the placenta, activation of alternate pathway can lead to a number of diseases. Immunotherapy is effective in the prevention of malignant transformation of hydatidiform mole. Immunotherapy and combination chemotherapy are markedly effective for treatment of metastatic chorionic malignancy.