HISTOCHEMICAL EVALUATION OF PLACENTAL DIPEPTIDYL PEPTIDASE-IV (CD26) IN PREECLAMPSIA - ENZYME-ACTIVITY IN VILLOUS TROPHOBLAST INDICATES AN ENHANCED LIKELIHOOD OF GESTATIONAL HYPERTENSIVE DISORDERS

PROBLEM: To determine whether differences in placental dipeptidyl pept idase IV (DPP IV, CD26) activities occurred in hypertensive complicate d pregnancies as compared with uncomplicated pregnancies. METHOD: DPP IV activity was detected with H-Gly-Pro-4M2NA as the substrate in plac ental cryostat sections from 65 patients with gestational hypertension and 67 patients with uncomplicated pregnancies. The graduated intensi ties of the reaction product in the villous trophoblast were scored se miquantitatively by light microscopy and were related to the relative frequencies of hypertensive disorders (proportional odds model). After detection of enzyme activity, the same tissue samples were homogenize d and used for kinetic fluorometric measurements. RESULTS: Enhanced vi llous trophoblastic DPP IV activity was significantly associated with an increased frequency of proteinuric hypertension in pregnant women ( cumulative odds ratio <(theta)over cap>(1) = 1.6; P < 0.01). CONCLUSIO N: This study demonstrates for the first time that increased villous t rophoblastic DPP IV activity indicates an increased likelihood of the presence and of the severity of hypertensive disorders in pregnancy.