Serum level of MicroRNA 15a and interleukin 6 as biomarkers for sepsis in critically Ill Patients

Abstract

This study intended to evaluate the diagnostic efficacy of serum interleukin-6 (IL-6) and serum expression level of microRNA 15a (miRNA 15a) in sepsis patients admitted to the medical intensive care unit (ICU), and to correlate the results with the outcome of patients. This observational case-control study, was done from January 2022 to June 2022, included 75 adult ICU patients ≥18 years old, divided into 2 groups. Group 1: included 38 adults, critically ill sepsis patients and Group 2 (control group), included 37 adults, non-sepsis patients admitted to the ICU. Venous blood was withdrawn from cases and controls under aseptic conditions for assessment of serum IL-6 level by ELISA and serum expression level of miRNA 15a by quantitative reverse transcriptase real-time polymerase chain reaction (qRT-PCR). Patient demographic data in addition to their characteristics including site of infection, blood culture results, length of stay and outcome of patients were included in the study. miRNA 15a was significantly higher in the sepsis group with mean of 3.99±1.61 compared to the controls (1.03±0.03, p< 0.001) while serum IL-6 levels were higher in the sepsis patients compared to the controls, however the difference did not reach statistical significance (p= 0.92). No difference was found in IL-6 and miRNA 15a levels between surviving and non-surviving sepsis patients, shocked and non-shocked sepsis patients. In conclusion, both IL-6 and miRNA 15a were up-regulated in ICU patients with sepsis. Both biomarkers did not show a significant difference regarding the outcome of patients. miRNA 15a could be considered a highly specific and sensitive marker in differentiating sepsis cases from controls, so it could be used as a diagnostic rather than a prognostic biomarker for sepsis.