Diagnosis of preeclampsia with soluble Fms–like tyrosine kinase 1/placental growth factor ratio: an inter–assay comparison

Abstract

The angiogenic factor ratio soluble Fms–kinase 1 (sFlt–1)/placental growth factor (PlGF) is a novel diagnostic tool for preeclampsia. We compared the efficacy of the KRYPTOR (BRAHMS) automated assays for sFlt–1 and PlGF with the Elecsys (Roche) assays in a routine clinical setting. Preeclamptic women (n = 39) were included shortly after the time of diagnosis. Normotensive control pregnancies were matched by gestational age (n = 76). The KRYPTOR assays performed comparably or superior to Elecsys (sFlt–1/PlGF area under the curve 0.746 versus 0.735; P = .09; for non–obese 0.820 versus 0.805, P = .047). For early–onset preeclampsia, KRYPTOR area under the curve increased to 0.929 with a 100% specificity for preeclampsia at cut–off 85 and an 88.9% sensitivity for preeclampsia at cut–off 33. For women with preeclampsia and preterm delivery or Hemolysis, Elevated Liver enzymes, Low Platelet count (HELLP) syndrome, the KRYPTOR sFlt–1/PlGF ratio was manifold increased (P < .01). The sFlt–1/PlGF ratio proved especially useful in early–onset preeclampsia, preeclampsia with preterm delivery or HELLP, and among non–obese women.