Diagnosis and management of latent tuberculosis (TB) infections are one of the challenges of eradicating pulmonary TB. A critical aspect of controlling pulmonary TB spread is early diagnosis. One TB biological marker type under evaluation is microRNAs (miRNAs). Mycobacterium tuberculosis infection causes epigenetic changes. The upregulation of miRNA-29a-3p suppresses the immune response by post-transcriptionally inhibiting interferon (INF)-γ expression in T cells, increasing susceptibility to pulmonary TB. This study aimed to assess miRNA-29a-3p expression as a biomarker of active and latent pulmonary TB infection. This case-control study included 50 individuals with active TB, 33 household contacts with a positive IFN-γ release assay (IGRA), and 30 healthy controls. An enzyme-linked immunosorbent assay-based IGRA was used to determine latent pulmonary TB infection in household contacts. Quantitative real-time PCR was used to quantify miRNA-29a-3p expression. Data analysis used analyses of variance and receiver operating characteristic (ROC) curves. miRNA-29a-3p expression differed significantly between active TB, latent TB, and healthy participants (controls; p = <0.001. ROC curve analysis showed that miRNA-29a-3p expression had 86% sensitivity and 73% specificity with an area under the ROC curve (AUC) of 0.763 (95% confidence interval [CI]: 0.668–0.858). The miRNA-29a-3p ROC curve had 84.8% sensitivity and 70% specificity with an AUC of 0.808 (95% CI: 0.698–0.919) for latent TB. Additionally, miRNA-29a-3p expression was significantly correlated with active (p < 0.0001) and latent (p < 0.0001) pulmonary TB. However, miRNA-29a-3p expression was not significantly correlated with INF-γ levels in patients with active (R = 0.005; p = 0.62) and latent (R = 0.010; p = 0.38) pulmonary TB or healthy controls (R = 0.060; p = 0.19). miRNA-29a-3p expression was increased in patients with active and latent pulmonary TB. Therefore, miRNA-29a-3p represents a potential biomarker for latent and active pulmonary TB. However, IFN-γ levels were not correlated with miR-29a-3p expression.

Background: Diagnosis of tuberculosis (TB) in the era of technological sophistication requires accuracy and speed to provide as much information as possible so that TB treatment can be carried out quickly and precisely. New studies have also begun to be carried out to diagnose TB, one of which is by examining genes, either by looking at polymorphisms, mutations, or expressions. Several previous studies have confirmed the association of MC3R and TB genes with polymorphisms; MC3R is a gene that participates in the regulation of the inflammatory process and is also found in macrophages; therefore, we tried to analyze gene expression in the active TB group, household contacts, and healthy controls for looked at the differences between the three groups and confirmed the correlation of MC3R with TB by seeing which group's gene expression increased the most expression of the three groups so that the results can be considered as a TB diagnostic biomarker in the future. Methods: This study included 122 people, 49 patients with confirmed TB, 46 close relatives of patients, and 27 healthy controls. This study used a real-time PCR technique to analyze MC3R gene expression in the three groups, and all data were analyzed using Bio-Rad CFXTM software version 3.1 and one-way ANOVA using SPSS 21.0. Results: The value of MC3R gene expression in the active TB group increased 3.6-fold in the healthy group (p = 0.143), and that of gene expression in the healthy control group increased 1.09-fold in the healthy group (p = 0.007). Conclusion: There is a relationship between MC3R and TB based on the results of gene expression analysis that increased in the active TB group compared to the household contact group and healthy controls.