Serum miR-126-3p level is down-regulated in sepsis patients

Endothelial injury is part of the pathogenesis of sepsis. The microRNA-126 (miR-126) was previously identified as an endothelial biomarker and is known to play a critical role in preserving endothelial cell integrity. However, the role of miRNA-126 in sepsis is unclear.

Blood samples were collected from sepsis patients at the first Affiliated Hospital of Sun Yat-sen University within 24 h (n = 60) and on day 7 (n = 51) after diagnosis, and once from control subjects (n = 46). MiR-126-3p expression was evaluated by quantitative real-time PCR. The miR-126-3p level was correlated with clinical data and a set of routine and experimental biomarkers. The outcome of sepsis patients was determined by follow-up at 28 days after collection of blood samples on day 7.

MiR-126-3p level was significantly downregulated in sepsis patients 24 h after diagnosis compared with control subjects. Degree of downregulation of serum miR-126-3p correlated with the severity of sepsis. To determine the diagnostic accuracy of miR-126-3p, the receiver operating characteristic (ROC) was performed and the AUC of miR-126-3p was 0.735. Furthermore, serum miR-126-3p concentration at this time point was correlated with the expression markers of systemic inflammation, bacterial infection, and renal and hepatic dysfunction. However, serum miR-126-3p level on day 7 day did not differ between surviving sepsis patients and those who died.

These results indicate that miR-126-3p could be a diagnostic biomarker for sepsis.