PLACENTAL PATHOLOGY IN ANTIPHOSPHOLIPID SYNDROME

One of the major targets of antiphospholipid antibodies (aPL) is the p lacenta, the evolution of which during pregnancy has been well documen ted. Histopathological findings are related to gestational age, and se veral physiologic and pathologic alterations that occur during its dev elopment. The major findings in placentae from aPL positive patients a re thrombosis, acute atherosis, a decreased number of syncytio-vascula r membranes, increased number of syncytial knots and obliterative arte riopathy. These findings are not specific to the antiphospholipid synd rome (APS) and sometimes do not correlate with the fetal outcome. Hist opathological study of placentae may elucidate mechanisms of action of aPL in fetal loss and other obstetric complications. In addition. it may assist in the investigation of the differential diagnosis between APS and pregnancy-induced hypertension. Immunohistochemical studies of local placental proteins contribute to this differential diagnosis.