Circulating miR-122-5p, miR-125b-5p, and miR-27a-3p in Post-Mortem Whole Blood: An Exploratory Study of the Association with Sepsis-Related Death

Accurate post-mortem diagnosis of sepsis remains a critical challenge in forensic pathology, as conventional morphological findings often lack specificity. Circulating microRNAs (miRNAs) have been proposed as stable molecular biomarkers, yet their diagnostic value in cadaveric samples is still unclear. This exploratory study investigated the expression of three candidate miRNAs (miR-122-5p, miR-125b-5p, and miR-27a-3p) in post-mortem peripheral whole blood to assess their association with sepsis-related death versus non-infective controls. Out of 58 cases, 45 met quality-control criteria (26 sepsis-related deaths and 19 controls). miRNA expression was quantified by qRT-PCR, normalized to miR-320, and analyzed using ΔCt values. Group differences were evaluated using linear regression models with adjustment for age, sex, and post-mortem interval, with Benjamini-Hochberg correction for multiple testing. In adjusted models, miR-125b-5p and miR-27a-3p showed evidence of association with sepsis status, whereas miR-122-5p did not. These results support the feasibility of miRNA quantification in post-mortem samples and motivate validation in larger, independent cohorts and within multimodal post-mortem diagnostic frameworks.