An Automated Assay for Growth Differentiation Factor 15.

BACKGROUND: Growth differentiation factor 15 (GDF-15) can serve as a biomarker for cardiovascular disease burden and risk. We evaluated a new, fully automated electrochemiluminescence immunoassay for measuring GDF-15. METHODS: Six laboratories independently characterized the Elecsys® GDF-15 assay (Roche Diagnostics) under routine conditions. Within-run precision (repeatability), within-laboratory precision (intermediate precision), and between-laboratory precision (reproducibility) were assessed. Plasma-serum sample correlation, reagent lot-to-lot reproducibility, and instrument comparisons were performed. The Elecsys assay was compared to a research immunoradiometric assay (IRMA) and a commercially available ELISA. GDF-15 concentrations were measured with the Elecsys assay in 739 apparently healthy individuals. RESULTS: CVs for within-run and within-laboratory precision ranged from 0.7% to 7.7% and 1.7% to 8.6%, respectively, for samples containing 670-16039 ng/L. CVs for between-laboratory precision ranged from 7.1% to 8.9% (766-14289 ng/L). Recovery of GDF-15 was comparable for serum, Li-heparin plasma, K2- and K3-EDTA plasma, and citrated plasma, between 2 reagent lots, and on the cobas e 411 and cobas e 601 analyzers (Roche Diagnostics). GDF-15 concentrations in the clinically relevant range (400-3000 ng/L) measured with the Elecsys assay showed a good correlation and agreement with those measured by IRMA or ELISA. GDF-15 concentrations in apparently healthy individuals increased with age but did not vary by sex. CONCLUSIONS: The Elecsys GDF-15 assay demonstrates a robust analytic performance under routine conditions and provides an automated method for measuring GDF-15 concentrations in serum and plasma.

Influence of the sFlt-1/PlGF Ratio on Clinical Decision-Making in Women with Suspected Preeclampsia.

OBJECTIVE: To evaluate the influence of the soluble fms-like tyrosine kinase 1/placental growth factor ratio in physicians' decision making in pregnant women with signs and symptoms of preeclampsia in routine clinical practice. METHODS: A multicenter, prospective, open, non-interventional study enrolled pregnant women presenting with preeclampsia signs and symptoms in several European perinatal care centers. Before the soluble fms-like tyrosine kinase 1/placental growth factor ratio result was known, physicians documented intended clinical procedures using an iPad® application (data locked/time stamped). After the result was available, clinical decisions were confirmed or revised and documented. An independent adjudication committee evaluated the appropriateness of decisions based on maternal/fetal outcomes. Clinician decision making with regard to hospitalization was the primary outcome. RESULTS: In 16.9% of mothers (20/118) the hospitalization decision was changed after knowledge of the ratio. In 13 women (11.0%), the initial decision to hospitalize was changed to no hospitalization. In seven women (5.9%) the revised decision was hospitalization. All revised decisions were considered appropriate by the panel of adjudicators (McNemar test; p < 0.0001). CONCLUSIONS: The use of the soluble fms-like tyrosine kinase 1/placental growth factor test influenced clinical decision making towards appropriate hospitalization in a considerable proportion of women with suspected preeclampsia. This is the first study to demonstrate the impact of angiogenic biomarkers on decision making in a routine clinical practice.

Influence of the sFlt-1/PlGF ratio on clinical decision-making in women with suspected preeclampsia--the PreOS study protocol.

OBJECTIVE: To assess how routine clinical use of the Roche fully automated Elecsys® sFlt-1/PlGF test changes decision-making of physicians to hospitalize pregnant women with suspected preeclampsia. METHODS: The Preeclampsia Open Study (PreOS) study is a multicenter, prospective, open-label, non-interventional study in 150 women showing signs and symptoms of preeclampsia (suspected preeclampsia). Physicians record their intended procedures before and after knowledge of participants' sFlt-1/PlGF ratio. The study is conducted at five investigational sites in Germany and Austria. CONCLUSION: The PreOS study will provide evidence on how sFlt-1/PlGF ratio testing influences clinical decision-making in women with suspected preeclampsia in real-world clinical practice.