Role of biomarkers (sFlt-1/PlGF) in cases of COVID-19 for distinguishing preeclampsia and guiding clinical management

Objectives: To analyze soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factors (PlGF) concen-trations and their ratio in pregnant and postpartum women with suspected COVID-19, and further investigate conditions associated with an increased ratio (sFlt-1/PlGF > 38), including preeclampsia (PE) and severe acute respiratory syndrome (SARS). Study Design: The present study is a secondary analysis of a prospective cohort. Blood samples were collected at time of COVID-19 investigation and the serum measurements of sFlt-1 and PlGF were performed. Clinical background, SARS-CoV-2 infection characteristics, maternal and perinatal outcomes were further analyzed. Main outcome measures: Serum measurements of sFlt-1 and PlGF; obstetrics and clinical outcomes. Results: A total of 97 SARS-CoV-2 unvaccinated women with suspected infection were considered, 76 were COVID-19 positive cases and 21 COVID-19 negative. Among COVID-19 positive cases, 09 presented with SARS and 11 were diagnosed with PE, of which 6 had SARS-CoV-2 infection in first and second trimester (04 with sFlt-1/PlGF >= 38) and 05 with PE and COVID-19 diagnosed at the same time, during third trimester (03 with sFlt-1/ PlGF >= 38). Five presented with PE with severe features. sFlt-1/PlGF ratio was significantly higher in the COVID-19 positive/PE positive group compared to COVID-19 positive/PE negative group (p-value = 0.005), with no increase in cases complicated by SARS. Conclusions: sFlt-1/PlGF ratio could be a useful tool for differential diagnosis and adequate counseling among cases of COVID-19 and PE, especially if severe disease. COVID-19 early in pregnancy could potentially be a risk factor for PE later during gestation.