Limited Diagnostic Value of miRNAs in Early Trauma-Induced Liver Injury: Only miRNA-122 Emerges as a Late-Phase...

Background/Objectives: Liver injury is common after abdominal trauma. However, the established biomarkers of liver injury, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), lack accuracy. This study investigates whether specific liver-related microRNAs (miRNAs) are released into the circulation in trauma patients with liver injury and whether they can indicate liver damage in the early phase after major trauma. Methods: A retrospective analysis of prospectively collected data and blood samples from 26 trauma patients was conducted. The levels of miRNA-21-5p, -122-5p, -191-5p, -192-3p, and -212-3p were measured in patients with computed tomography-confirmed liver trauma (LT group, n = 12) and polytrauma patients without liver trauma (PT group, n = 14) upon emergency room (ER) admission, and 24 and 48 h after trauma. Additionally, liver-type fatty acid binding protein (L-FABP) was measured, as it has recently been discussed in the context of abdominal trauma. Results: Only miRNA-122-5p showed a significant increase in the LT group compared to the PT group, but only at the 48 h time point (p = 0.032). Conversely, L-FABP (p = 0.018) and ALT (p = 0.05) were significantly elevated in the LT group compared to the PT group at the time of ER admission. There was a moderate correlation between miRNA-122-5p and AIS_Abdomen (p = 0.056) and transfused red blood cell concentrates (p = 0.055). L-FABP correlated strongly with the ALT levels (p = 0.0009) and the length of stay in the ICU (p = 0.0086). Conclusions: In this study, the liver-specific miRNA-122-5p did not effectively indicate liver injury in the early acute post-traumatic phase. Future research with a large sample size should investigate whether other miRNAs can more accurately predict liver injury and the extent of hepatocellular injury, particularly in the acute post-traumatic phase.