Role of miRNA-144-3p as a Biomarker for Differentiation of Active Pulmonary Tuberculosis From Latent Tuberculosis

Abstract Individuals with latent tuberculosis infection (LTBI) are possible reservoirs for active tuberculosis. Currently, TST and IGRA are used to diagnose LTBI, but neither can distinguish between active TB and LTBI. The purpose of this study was to assess serum miRNA-144-3p's biomarker potential for distinguishing active pulmonary tuberculosis and latent tuberculosis. Data on 106 adult participants were collected at the Department of Microbiology, Ibrahim Medical College, Dhaka. The participants included healthy people (n = 56), diagnosed pulmonary tuberculosis cases (n = 40), and people with other respiratory diseases as disease control (n = 10). All individuals underwent a tuberculin skin test. Healthy subjects were divided into healthy control and latent tuberculosis groups based on TST reactivity. All recruited subjects had their whole blood drawn, and serum was separated. Total RNA, including miRNA, was isolated, and cDNA templates were created. The expression of miR-144-3p was measured using real-time PCR with specific primers and probes. The relative expression of miR-144-3p in different groups was calculated using the comparative 2−ΔΔCt method. Serum miR-144-3p expression level in the newly diagnosed active pulmonary TB group was significantly higher than the healthy controls (P < 0.001). Area under the curve (AUC) of serum miR-144-3p was 0.960 in ROC curve analysis. At the cutoff value of 2.49, the sensitivity and specificity reached 90% and 95%, respectively, for diagnosing active pulmonary TB. On the contrary, the expression of miR-144-3p in the latent TB group compared to healthy controls (P = 0.304) was not statistically significant. In ROC curve analysis, AUC was found to be 0.595, which indicates poor discrimination with the healthy control group. A significant difference in miR-144-3p expression was observed in the treated group compared to the newly diagnosed active pulmonary TB group (P = 0.001). miR-144-3p is not a suitable biomarker for detecting latent TB as it failed to discriminate between healthy control and latent TB groups. However, an increased serum level of miR-144-3p could be used as a diagnostic marker for active pulmonary TB, and reduced serum levels of miR-144-3p after treatment could be used as a prognostic marker.