Study of MicroRNA-122 as a Diagnostic Biomarker of Sepsis

Sepsis in intensive care units (ICUs) represent a threat with need for rapid and accurate diagnosis. We aimed to assess miR-122 as an early biomarker for diagnosis and outcome prediction in patients with hospital acquired sepsis in ICU. This case control study included 25 adults' patients with sepsis and 25 patients with local wound infections as a control group. C-reactive protein (CRP), total leucocytes count (TLC), liver function, and molecular determination of miR-122 levels were assessed. miR-122 had significant higher area under curve (AUC) when compared with CRP and TLC for differentiation of sepsis from wound infections. The cut off value for miR-122 was 0.16 folds expression with sensitivity, specificity and accuracy 100%. The TLC cut off value was 14.00 x103/cmm with 100% sensitivity, 84% specificity and 92% accuracy. While CRP cut off value was 41 mg/l with 76.0% sensitivity, 100% specificity, and 88.0% accuracy. Multivariate logistic analysis revealed non statistically significant difference between survivors and non survivors regarding sepsis biomarkers. Receiver operation curve (ROC) for different biomarkers, CRP, TLC and miR-122 to differentiate patients with poor outcome of sepsis compared to patients with recovery, revealed that AUC was 0.61, 0.6, and 0.45 respectively. miR-122 as a prognostic biomarker for sepsis had 66.6% sensitivity, 50% specificity, and 56.0% accuracy. The present study highlights important points in the use of biomarkers in diagnosis of sepsis in adults' patients above 50 years old. miR-122 is an accurate and specific biomarker for diagnosis of sepsis. miR-122 has limited predictive value for determination of the outcome of patients with sepsis even when used in combination with another biomarker such as CRP and TLC.