Angiogenic factors as diagnostic tests for preeclampsia: a performance comparison between two commercial immunoassays.

Abstract

Placental growth factor and soluble Fms-like tyrosine kinase-1 may be potential diagnostic markers of preeclampsia. We compared performances of 2 immunoassays, the Triage placental growth factor assay and the Elecsys soluble Fms-like tyrosine kinase-1/placental growth factor ratio in diagnosing preeclampsia. A single site, case-control study of 44 patients with preeclampsia and 84 matched normal pregnant controls. Samples were collected at the time of diagnosis. Assays were performed according to product inserts. Both assays had optimal performance in diagnosing early-onset preeclampsia with area under the receiver operating characteristic curves of 0.99 (Triage: 100% sensitivity, 96% specificity; Elecsys: 64% sensitivity, 100% specificity for early-onset preeclampsia). Reassignment of the Elecsys cutoff for a positive test based on receiver operating characteristic curves increased sensitivity to 92%. Using product insert cutoffs, Triage appears to have greater sensitivity at only a small reduction in specificity compared with Elecsys in the diagnosis of early-onset preeclampsia. A different cutoff may improve Elecsys sensitivity.