INHIBIN-A AND PRO-ALPHA-C ARE ELEVATED IN PREECLAMPTIC PREGNANCY AND CORRELATE WITH HUMAN CHORIONIC-GONADOTROPIN

PROBLEM: Serum concentrations of the heterodimeric glycoprotein inhibi n-A (alpha-beta(A)) and its alpha-subunit increase during pregnancy. T he placenta is the predominant source of inhibin during pregnancy, and a paracrine role in the trophoblast has been suggested. Elevated seru m concentrations of inhibin alpha-subunit as well as the glycoprotein human chorionic gonadotropin (hCG) have been described in preeclamptic pregnancy. The objectives of this investigation were to compare serum concentrations of inhibin-A and inhibin pro-alpha C in preeclamptic a nd normotensive pregnancy, and to examine the relationship of hCG and inhibin-A in those pregnancies. METHOD OF STUDY: A case-control design using 32 patients with preeclampsia with a single fetus at 32-40 week s of gestation and 34 gestation age-matched normotensive control subje cts was used for this investigation. Solid-phase enzyme-linked immunos orbent assays were used to measure inhibin-A and inhibin pro-alpha C i n sera. An immunoradiometric assay was used to measure intact hCG. RES ULTS: Inhibin-A and inhibin pro-alpha C concentrations were significan tly elevated in the sera of women with preeclampsia compared with thos e concentrations in normotensive control subjects (P < 0.05). A relati onship of inhibin-A or pro-alpha C with severity of preeclampsia was n ot observed. There was a significant positive correlation of serum hCG with both inhibin-A and pro-alpha C (P < 0.05). CONCLUSIONS: Levels o f inhibin-A and the subunit pro-alpha C are increased in pregnancies c omplicated by preeclampsia. These findings are potentially the effect of a paracrine role of inhibin-A in the development and proliferation of the trophoblast.