Basic performance assessment of reagents for measuring soluble FMS-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) in Japanese women

Among the factors associated with angiogenesis, soluble FMS-like tyrosine kinase-1 (sFlt-1) is antiangiogenic and placental growth factor (PlGF) is proangiogenic. The sFlt-1/PlGF ratio is considered useful for the short-term prediction of preeclampsia (PE) in high-risk pregnancies and has been used clinically in Japan since July 2021. Regarding the clinical use of the sFlt-1/PlGF ratio in Japan, there have been no published reports demonstrating that sFlt-1 and PlGF assay reagents have the same basic performance in Japanese and European women. To our knowledge, we conducted the first basic performance assessment of the sFlt-1 and PlGF assay reagents using sera from Japanese women. We obtained satisfactory results for repeatability, intermediate precision, linearity, effects of interferents, and the LoQ. The sFlt-1 and PlGF assay reagents performed well, and we believe that they are entirely adequate for use in routine clinical assays of Japanese patients, similar to those in European patients.