MicroRNAs as a Diagnostic Tool in Bacterial Infections: A Review Article

Background: Severe sepsis and tuberculosis are major causes of mortality due to infection all over the world. The impact of microRNAs (miRNAs) in activating the immune process during bacterial infections is essential and associated with managing gene expression of inflammatory markers. Objective: To find the available evidence regarding the diagnostic potential and mechanistic utility of total circulating miRNAs and EV-derived miRNAs in human bacterial infections, that is, sepsis and TB. Methods: This study is based on a PRISMA-DTA literature review. In this study, a comprehensive search was conducted on different databases such as PubMed, Embase, Web of Science, and Scopus between 1 January 2013 and 15 February 2025 for papers related to this topic. The risk of bias was assessed by the QUADAS-2 tool. Results: We evaluated 46 records on sepsis, tuberculosis, severe pneumonia, and bacterial meningitis out of 1,319 records. Most of the studies, about 74%, were case-control using 65% serum, 38% plasma, and 82% qRT-PCR. Sepsis circulating microRNAs showed moderate-to-high diagnostic accuracy, where miR-155-5p AUC=0.81, miR-223 AUC=0.79, and multi-miRNA panels up to AUC=0.90; severe pneumonia showed miR-155 AUC=0.79, miR-34a AUC=0.81, and miR-150 AUC=0.83; tuberculosis showed miR-29a AUC=0.81 and panels including miR-144 and miR-197 AUC=0.87; and bacterial meningitis showed CSF miR-181a AUC=0.82, plasma miR-223 AUC=0.79, and CSF miR-125b AUC=0.84. Conclusions: MicroRNAs in the circulation have demonstrated moderate-to-high forms of diagnostic accuracy among various bacteria and their infections, such as sepsis, tuberculosis, severe pneumonia, and bacterial meningitis.