Circulating MicroRNA 29a: An Evolving Biomarker for Diagnosis of Pulmonary Tuberculosis

Abstract

Introduction: Tuberculosis (TB) is global health problem threatening millions every year. There is urgent need of effective biomarkers for its diagnostics and circulating microRNAs (miRNAs) have recently emerged as novel and non-invasive molecular markers in blood. Aim: This study was done to evaluate serum miRNAs as a potential biomarker for the diagnosis of pulmonary mycobacterium tuberculosis infection. Materials and Methods: In this prospective cross-sectional study, acute pulmonary TB patients were recruited based on positive Mycobacterium tuberculosis Polymerase Chain Reaction (PCR) in sputum samples and Microarray expression profiling was performed on blood of these patients to study differentially expressed miRNAs. The results were validated by Real-Time Polymerase Chain Reaction (RT-PCR) on pulmonary TB cases and healthy controls. Student’s t-tests and analysis variance tests were used for statistical analysis. The p-value <0.05 was considered statistically significant. Results: Results of microarray expression profiling showed 75 differentially expressed miRNAs in cases of pulmonary TB; among these 5 upregulated and 2 downregulated miRNAs were evaluated by RT-PCR. miRNA 29a exhibited good distinguishing efficiency; followed by miRNA 384. ROC plot of expression data for miRNA in cases and control groups showed that AUC of miRNA-29a was 0.8268 (sensitivity=80%, specificity=82%) . Conclusion: This study suggests that altered levels of serum miRNAs have great potential to serve as non-invasive biomarkers for detection of Mycobacterium tuberculosisinfection. miRNA-29a can be used as an effective biomarker for diagnosis of pulmonary TB.