Haptoglobin phenotype, angiogenic factors, and preeclampsia risk.

Abstract

We sought to determine whether haptoglobin (Hp) phenotype is related to preeclampsia risk, or to plasma concentrations of soluble endoglin (sEng), soluble fms-like tyrosine kinase 1 (sFlt-1), and placental growth factor (PlGF). Hp phenotype was retrospectively determined in primiparous women with uncomplicated pregnancies (n = 309), gestational hypertension (n = 215), and preeclampsia (n = 249). Phenotype was assessed by peroxidase staining following native polyacrylamide gel electrophoresis of hemoglobin-supplemented serum. Compared with Hp 1-1, Hp 2-1 was associated with a significantly increased risk of preeclampsia (odds ratio, 2.11; 95% confidence interval, 1.07-4.18) and term preeclampsia (odds ratio, 2.45; 95% confidence interval, 1.07-5.83) in Caucasian women. Hp phenotype was not associated with preeclampsia risk in African Americans. Preeclamptic women had higher plasma sEng and sFlt-1, and lower PlGF, than control subjects. sEng, sFlt-1, and PlGF did not differ among women of different Hp phenotypes. Hp 2-1 is associated with higher preeclampsia risk in primiparous Caucasian women.