Glycosylated Fibronectin Compared With sFlt-1/PlGF Ratio for Preeclampsia Assessment

The ratio of sFlt-1 (soluble fms-like tyrosine kinase 1) to PlGF (placental growth factor) is an established biomarker for preeclampsia diagnostic triage. GlyFn (glycosylated fibronectin) measured by point-of-care testing is an alternative rapid assessment from finger-stick blood samples. This study was designed to test the hypothesis that the sensitivity of GlyFn is noninferior to that of the sFlt-1/PlGF ratio in women with suspected preeclampsia.

This prospective observational study evaluated the diagnostic accuracy of both tests for preeclampsia in high-risk participants presenting between 24⁺⁰ and 36⁺⁶ weeks of gestation at 5 hospitals from January 2024 to July 2025. Participants underwent simultaneous point-of-care GlyFn testing (Lumella) and laboratory sFlt-1/PlGF ratio measurements. The primary outcome was birth for preeclampsia within 28 days of testing. Thresholds were set at GlyFn ≥350 μg/mL and sFlt-1/PlGF ratio ≥38. The noninferiority margin was predefined at 5%.

Among 397 participants, 59 (14.9%) had an indicated birth for preeclampsia within 28 days. GlyFn showed a sensitivity of 86.44% (95% CI, 75.02%-93.96%) compared with sFlt-1/PlGF 84.75% (95% CI, 73.01%-92.78%). Although sensitivities were numerically similar (P=0.79), the CI around the difference was too wide to establish noninferiority at the 5% margin. Negative predictive values were 96.40% and 96.59%, respectively. However, GlyFn had a lower specificity (63.31% versus 75.44%, P<0.01).

Point-of-care GlyFn testing showed similar sensitivity and negative predictive value to the sFlt-1/PlGF ratio for predicting an indicated birth for preeclampsia within 28 days. The point-of-care nature of the GlyFn test may facilitate immediate clinical decision-making in diverse healthcare settings.

URL: https://doi.org/10.1186/ISRCTN13430018; Unique identifier: ISRCTN13430018.