BACKGROUND: P-selectin exists in two biologically distinct forms, soluble in plasma (sP-selectin) and membrane-bound on activated platelets (CD62P). Both have been linked to the pathophysiology of preeclampsia, but their comparative diagnostic and predictive performance have not been systematically analyzed. We conducted an original dual meta-analysis comparing soluble and platelet-bound P-selectin for the diagnosis and early prediction of pre-eclampsia. METHODS: We systematically reviewed and pooled published data up to April 2025. Studies assessing sP-selectin via ELISA or CD62P via flow cytometry were included. Diagnostic and first-trimester predictive performance were analyzed separately. Pooled effect sizes (Hedges' g), relative risks (RR), predictive values (PPV, NPV), and number needed to predict (NNP) were calculated based on extracted group-level data. RESULTS: Soluble P-selectin was moderately elevated in manifest preeclampsia (g = 1.08, RR = 2.17, PPV = 78%) and showed predictive utility in early pregnancy (g = 0.95, RR = 2.10, NPV = 90%). Platelet-bound CD62P demonstrated markedly stronger associations in both settings: diagnostic (g = 4.85, RR = 17.1, PPV = 90%) and predictive (g = 2.50, RR = 3.0, NPV = 95%). Our pooled data analysis shows CD62P to be superior in clinical discrimination. CONCLUSIONS: This is the first direct, meta-analytic comparison of sP-selectin and CD62P in preeclampsia. Our original data synthesis confirms CD62P as a stronger biomarker in both diagnostic and predictive contexts. Where flow cytometry is available, CD62P should be preferred. sP-selectin remains useful as an early rule-out tool in screening protocols.
Sucker et al. (2026) studied this question.