Expression patterns of circulating microRNA in confirmed early-onset and late-onset pre-eclampsia cases

Abstract Purpose The aim of our study was to investigate selected pre-eclampsia (PE)-related miRNAs in clearly defined early- and late-onset PE (eoPE, loPE) cohorts and compare them with healthy controls. Methods This is a single-center, pilot study comparing pregnancies with eoPE (n=10) and loPE (n=8), each with separate healthy controls (n=10; n=8). Serum miRNA (miR-) expression levels of selected PE-associated miRNAs (miR-210-3p, miR-518b) were quantified by real-time PCR. Results Similar expression profiles (delta CT ± standard deviation) were observed between loPE vs. controls: miR-210-3p (8.20 ± 1 vs. 7.48 ± 1.2; p=0.16; Hodges-Lehmann estimator (HL): − 0.73, 95% confidence interval (CI) − 2.2 to 0.78) and miR-518b (9.82 ± 1.1 vs. 9.60 ± 0.9; p=0.80, HL: − 0.14, 95% CI − 1.61 to 0.91). Comparing eoPE cases to controls, we found an increase of miR-210-3p concentration (7.63 ± 1.1 vs. 9.31 ± 1.9; p=0.019; HL: 1.23, 95% CI 0.15 to 2.66, mean fold change: 3.2; sensitivity analysis: p=0.067) and a numerical difference in miR-518b expression without reaching statistical significance (8.77 ± 1.4 vs. 9.85 ± 1.8; p=0.19; HL: 0.70, 95% CI − 0.33 to 2.41; mean fold change: 2.1). Conclusion In the eoPE, miR-210-3p levels were higher than in controls, with the same trend observed in the sensitivity analysis, although statistical significance was no longer reached (p=0.067). miR-518b showed a numerical, non-significant difference between eoPE and controls. No significant differences were observed in loPE. Given the small sample size and overlap with early-onset fetal growth restriction, these findings should be considered exploratory.