Technical performance of the first fully automated assays for human soluble fms-like tyrosine kinase 1 and human placental growth factor

Introduction: An imbalance in circulating antiangiogenic soluble fms-like tyrosine kinase 1 (sFlt-1; sVEGFR-1), a splice variant of Flt1, and placental growth factor (PlGF), a proangiogenic protein, appears to be involved in the pathogenesis of preeclampsia (PE). Pregnant women who develop PE exhibit higher circulating levels of sFlt-1 and decreased levels of PlGF. sFlt-1 is an antagonist of VEGF and PlGF and seems to contribute to the pathogenesis of PE by absorbing free VEGF and PlGF in the maternal circulation and thereby preventing interaction with their respective membrane receptors. Automated immunoassays were established for convenient sFlt-1 and PlGF measurements for calculation of a sFlt-1 to PlGF ratio which may be an even better metric to diagnose PE than either measure alone.