EP17.06: Inter‐manufacturer assessment of the diagnostic performance of angiogenic ratio versus glycosylated fibronectin in women with suspected pre‐eclampsia

To compare the diagnostic performance of different manufacturers' angiogenic ratio with a point-of-care (PoC) test in women with suspected pre-eclampsia (PE). Archived maternal serum samples were retrieved from 236 East Asian women with singleton pregnancy presented with hypertension +/- clinical features of PE after 20 weeks. Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) levels were measured using the Cobas e411, Kryptor and Imagin1800. Glycosylated fibronectin (GlyFn) levels were measured using the LumellaTM PE PoC test. Predictive performance of each test to rule-out PE within 7 days and rule-in PE within 28 days from date of presentation. The sFlt-1:PlGF ratio was classified as high or low using platform-specific thresholds equivalent to a Cobas e411 sFlt-1:PlGF ratio of 38. Imagin1800 angiogenic ratio equivalent to a Roche sFlt-1:PlGF ratio of 38 was determined using Passing-Bablok regression. GlyFn was categorised as high or low using three reported clinical thresholds (263 and 510 ug/ml). 70 women developed PE with 36 and 70 within 7 and 28 days respectively. The negative predictive value (NPV) of Cobas e411, Kryptor and Ningbo-Aucheer sFlt-1:PlGF ratio to rule-out PE within 7 days of presentation were 83.3%, 82.0% and 82.9% whilst that for GlyFn >263 and >510 mg/ml were 82.6% and 70.4%. Corresponding positive predictive value (PPV) to rule-in PE within 28 days were 50.5%, 52.3%, 46.7% for sFlt-1:PlGF ratio, and 35.4% and 50% for GlyFn >263 and >510 ug/ml respectively. Both GlyFn and sFlt-1:PlGF can rule-out PE within 7 days with a moderate NPV. The PPV for ruling in PE within 28 days remains poor. The GlyFn test offers advantages over the sFlt-1:PlGF test, as it is a finger stick test suitable for various settings, including low-resource environments for home self-monitoring test.