Evaluating glycosylated fibronectin for rule-in and rule-out of pre-eclampsia in suspected cases

Accurate diagnosis of pre-eclampsia in women presenting with suspected disease remains challenging. Placental growth factor (PlGF) assays are established diagnostic biomarkers, particularly before 34 weeks' gestation. Glycosylated fibronectin (GlyFn), a metabolic biomarker, may provide complementary diagnostic information.

Retrospective diagnostic accuracy study using stored serum samples from 242 women with suspected pre-eclampsia recruited to the PEACHES study at two London maternity centres. GlyFn concentrations were measured using the Lumella™ DiabetOmics point-of-care test. Diagnostic performance for prediction of pre-eclampsia within 2, 7, 14, and 28 days was evaluated across gestational windows and compared with Delfia Xpress PlGF and Lepzi® Quanti point-of-care PlGF assays tested in the same cohort. Receiver-operating characteristic curves, sensitivity, specificity, predictive values, and likelihood ratios were calculated.

Pre-eclampsia occurred in 22.7% of participants (54/242). Optimal GlyFn thresholds were < 400 μg/mL for rule-out and ≥ 700 μg/mL for rule-in. Before 34 weeks' gestation, GlyFn < 400 μg/mL showed sensitivity 86.7% (95% CI 59.5-98.3) and negative predictive value 95.2% (83.8-99.4) for prediction within 14 days, although specificity was low (36.4%). PlGF assays showed higher diagnostic accuracy before 34 weeks (AUROC 0.88-0.90) compared with GlyFn (AUROC 0.70). GlyFn concentrations were moderately inversely correlated with PlGF (Spearman's ρ =  - 0.42, p < 0.001). Exploratory analyses suggested improved discrimination when both biomarkers were combined.

The Lumella™ GlyFn point-of-care is a promising biomarker for ruling out pre- eclampsia, particularly at later gestations. While PlGF remains superior for early preterm disease, GlyFn may provide complementary diagnostic information and warrants further prospective evaluation.