Micro-RNA: A potential screening marker for latent tuberculosis

An ancient disease, Tuberculosis is one of the most challenging infectious disease contributing to mortality and morbidity worldwide. Tuberculosis elimination globally, by 2050, is a mammoth task as Mycobacterial infections have wide range of presentation, from the clinical to the subclinical or latent and pose a diagnostic and therapeutic challenge. The virulence as well as evading property of Mycobacterium tuberculosisMtb) from the host's immune system confers upon it the ability to remain latent in the host cells. This forms the basis of classification of tuberculosis patient as having latent-TBI or active TB. This review focuses on the role of miRNA as biomarkers of LTBI. The aim is to have an overview of the current knowledge about miRNA, its involvement in TB pathogenesis and its role as a reliable tool for diagnosis of latent tuberculosis.miRNA are non-encoding endogenous RNAs which regulate gene expression by directing their target RNA for degradation or translational repression. Degraded RNA are released in the extracellular milieu, are present in various body fluids, such as blood, saliva, and urine, and are biomarkers for a number of diseases including cancer, Parkinsons’ disease, CAD, liver diseases, TB and other infectious diseases. miRNAs are differentially expressed during active TB and LTBI, and therefore can be used as biomarkers of disease progression and response to anti-TB therapy. This will further permit more specific therapeutic interventions in TB management. A thorough search of available literature resources was performed on online databases such as Google Scholar, NCBI, Nature, Research gate, PubMed, Science Direct. It was found that miRNA are promising biomarkers to identify healthy latent TB individuals for further course of action and can be reliable tools for routine use in current clinical practice for specific therapeutic interventions to limit active TB population. They meet the criteria of ideal biomarkers, such as minimally invasive, accessibility, high specificity, and sensitivity.