B-017 Prototyping Preeclampsia antibodies for chemiluminescence assays

Abstract Background In clinical laboratory settings, measuring the circulating levels of Fms-like tyrosine kinase, also known as Vascular Endothelial Growth Factor Receptor 1 (sFlt-1) and Placental growth factor (PlGF) are crucial in diagnosing preeclampsia, along with other medical parameters. Preeclampsia is responsible for 10-15% of maternal deaths worldwide, according to the World Health Organization (WHO). Elevated levels of sFlt-1 have been found in hypoxia or impaired perfusion of the placenta. PlGF levels are significantly lower in women with preeclampsia than in those with normal pregnancies or gestational hypertension (high blood pressure during pregnancy without signs of organ damage). Methods Newly developed biomaterials such as pair of antibodies for preeclampsia markers have been prototyped using BIO-FLASH® chemiluminescence autoanalyzer for checking their functional performance. Biomaterial prototyping has the objective to support internal biomaterial development by giving feedback for identification of the best candidates and for the definition of optimal downstream processes. These biomaterials have been coated to magnetic particles resuspended in reference buffers and tested with appropriate proteins labeled with isoluminol and substrates for the chemiluminescence reaction. Results Thermal stabilities of these protein-coated microparticles have been assessed with satisfactory results (less than 15% bias in performance versus reference). Standard assay definitions have been applied to get appropriate dose curve responses with internal reference materials in preliminary assay ranges of 3-8,792pg/ml for PlGF and 100-85,000pg/ml for sFlt-1. Functional performance has been evaluated with at least 40 individual clinical samples comparing to commercial reference assays. For s-Flt-1 and PlGF, a correlation coefficient over 0.9 has been achieved. Finally, cross-reactivity studies have been conducted for these antibodies, with no cross-reactant markers detected. Conclusion Prototyping has helped de-risking these preeclampsia antibodies developed for new chemiluminescent immunoassays when comparing to specific reference assay which uses proprietary antibodies. This characterization may last from three to six months and can accelerate the identification of good raw critical materials before starting the proper assay development phases.