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

BACKGROUND: 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. METHODS: 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%. RESULTS: 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). CONCLUSIONS: 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. REGISTRATION: URL: https://doi.org/10.1186/ISRCTN13430018 ; Unique identifier: ISRCTN13430018.