Expression of and As Biomarkers in Active and Latent Pulmonary Tuberculosis

Background: 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). infection causes epigenetic changes. The upregulation of suppresses the immune response by post-transcriptionally inhibiting interferon ()- expression in T cells, increasing susceptibility to pulmonary TB. This study aimed to assess expression as a biomarker of active and latent pulmonary TB infection.

Methods: This case-control study included 50 individuals with active TB, 33 household contacts with a positive IFN- 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 expression. Data analysis used analyses of variance and receiver operating characteristic (ROC) curves.

Results: expression differed significantly between active TB, latent TB, and healthy participants (controls; = <0.001. ROC curve analysis showed that 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, expression was significantly correlated with active ( < 0.0001) and latent ( < 0.0001) pulmonary TB. However, expression was not significantly correlated with INF-γ levels in patients with active (R = 0.005;  = 0.62) and latent (R = 0.010;  = 0.38) pulmonary TB or healthy controls (R = 0.060;  = 0.19).

Conclusion: 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 expression.