Background: Various scoring systems have been developed to determine the trauma severity and prognosis of patients following multiple blunt trauma (MBT). However, these scoring systems do not provide exactly the desired severity assessment. In recent years, serum concentration of many specific microRNAs (miRNAs), especially for head trauma, has been shown to play an important role in determining the diagnosis, severity, and prognosis of injury. To date, however, no studies have investigated serum miRNAs in patients with MBT. Thus, this study measured the expression of miRNA-93 and -191 in the serum of adults with MBT and examined the correlations of Injury Severity Score (ISS) and Revised Trauma Score values with serum miRNA-93 and -191 levels in these patients with the aim of predicting trauma severity based on the miRNA levels.
Methods: This prospective case-control study enrolled 50 consecutive adults with MBT and age- and sex-matched 60 healthy controls. The patients were divided into ISS >16 (Group 1, major or severe trauma) and ISS ≤16 (Group 2, minor or mild-moderate trauma) groups. Serum miRNA-93 and -191 levels were assessed using quantitative real-time reverse transcription-PCR. We evaluated whether the miRNAs were differentially expressed in major and minor MBT patients and determined their utility for assessing the severity of injury.
Results: The mean serum miRNA-93 and -191 levels were significantly elevated in the patients compared to the controls and were higher in patients with ISS >16 compared to those with ISS ≤16, although the difference was not significant. In the patients with multitrauma, ISS was significantly, negative and weak correlated with serum miRNA-191 level (rho=-0.320, p=0.023) but not with the serum miRNA-93 level. No optimal cutoff for the serum miRNA-93 level was found with respect to trauma severity (AUC 0.617, [0.455-0.779]). However, an optimal cutoff value for serum miRNA-191 was identified, with values <1.94 indicating severe trauma (AUC 0.668 [0.511-0.826]; 65.6% sensitivity, 77.8% specificity).
Conclusion: miRNA-191 and -93 levels were significantly upregulated in multitrauma patients compared to controls. The level of miRNA-191 in conjunction with ISS, but not that of miRNA-93, may be a useful biomarker for determining injury severity in patients with multitrauma.