Urinary Nephrin Concentrations in Preeclampsia (with and without Complications) vs Normal Pregnancies

BACKGROUND Preeclampsia disrupts the balance between anti-angiogenic and angiogenic factors, causing renal damage characterized by glomerular endotheliosis. Nephrin, a podocyte-specific transmembrane protein, shows promise as an early biomarker for preeclampsia, particularly in acute kidney injury preceding microalbuminuria. This study evaluated urinary nephrin concentrations in preeclampsia with and without complications and normal pregnancies. MATERIAL AND METHODS This study employed a prospective analytical observational approach with a cross-sectional design to measure urinary nephrin concentrations among 120 pregnant women (40 with uncomplicated preeclampsia, 40 with preeclampsia accompanied by complications, and 40 with normal pregnancies). Urinary nephrin concentrations were measured using enzyme-linked immunosorbent assay (ELISA) kits. Statistical analysis was conducted using IBM SPSS 26.0 for Windows. A P value <0.05 was considered statistically significant. RESULTS The mean maternal ages were similar across groups: 29.58±6.205 in the normal pregnancy group, 29.95±6.695 in the preeclampsia without complications group, and 29.98±6.265 years in the preeclampsia with complications group (P=0.952). Gestational ages ranged from 20 to 40 weeks, with preeclampsia groups predominantly in the 28-34 weeks range. Urinary nephrin concentrations were significantly higher in the preeclampsia group (4.59±1.051 without complications and 9.12±1.225 with complications) compared to the normal pregnancy group (1.11±0.356; P<0.0001). Elevated urinary nephrin levels in uncomplicated preeclampsia suggest early glomerular injury, even in the absence of severe clinical symptoms or complications. CONCLUSIONS Urinary nephrin levels are elevated in preeclampsia, with higher concentrations in complicated cases, highlighting its potential as a biomarker for renal involvement severity in preeclampsia.