Aim One of the main challenges in Tuberculosis (TB) control is the large number of undetected or late-diagnosed cases each year, especially among high-risk populations. miR-let-7f-5p and miR-223-3p are potential biomarkers for TB infection, but studies in pulmonary TB patients and household contacts remain limited. This study aimed to evaluate these two miRNAs as potential biomarkers for identification of TB infection in the Indonesian population. Methods This cross-sectional study evaluated the expression of these two miRNAs in patients with newly diagnosed active pulmonary TB (PTB), household contacts with latent TB infection (LTBI), and healthy contacts (HS) in Indonesia. The expression of miR-let-7f-5p and miR-223-3p was analyzed using quantitative real-time PCR (qPCR). Home visits were conducted to recruit household contacts of TB patients and collect samples, with latent TB infection assessed using the Interferon-Gamma Release Assay (IGRA). Results miR-let-7f-5p and miR-223-3p expression differed significantly among three groups (PTB, LTBI, and HS). miR-let-7f-5p was downregulated in PTB (p = 0.009) and LTBI (p = 0.0001) compared to HS, whereas miR-223-3p was upregulated in PTB (p = 0.009) and LTBI (p = 0.018) compared to HS. ROC curve analysis showed that both miRNAs significantly distinguish PTB and LTBI from HS. Conclusion Our findings provide preliminary evidence supporting miR-let-7f-5p and miR-223-3p as potential candidate biomarkers for identifying TB infection among high-risk populations, particularly household contacts. Further longitudinal and prospective studies involving larger and independent cohorts are needed to validate their diagnostic utility.
Background The rpoB S450L mutation is the most prevalent high-fitness rifampicin resistance-conferring mutation in Mycobacterium tuberculosis. However, numerous alternative rpoB mutations associated with varying fitness costs have been reported, particularly in specific clinical settings. This systematic review critically evaluates the relationship between low-fitness rpoB mutations, host immune status, HIV co-infection, compensatory evolution, and diagnostic discordance. Methods A systematic literature search was conducted across multiple scientific databases. Studies reporting genetic, phenotypic, structural, or clinical data on rifampicin-resistant M. tuberculosis carrying alternative or borderline rpoB mutations were included. Data were qualitatively synthesized to examine associations among host immune status, bacterial fitness, compensatory evolution, and diagnostic performance. Results Twenty-one studies met the inclusion criteria. Available clinical evidence indicated a higher prevalence of low-fitness non-S450L rpoB mutations, particularly at codons 430, 435, 441, and 445, among patients with advanced HIV infection. The available evidence suggests that HIV-associated immunosuppression may reduce host-driven purifying selection, facilitating the persistence of low-fitness resistant variants. Genomic and structural studies identified compensatory mutations in rpoA, rpoB, and rpoC that may partially restore bacterial fitness while maintaining rifampicin resistance. Several borderline rpoB mutations also produced discordant results between molecular assays and phenotypic drug susceptibility testing. Conclusion HIV-associated immunosuppression may influence the evolutionary trajectory of rifampicin-resistant M. tuberculosis by facilitating the persistence of low-fitness rpoB mutations. Integrating molecular diagnostics, genomic surveillance, and host immune profiling may improve the detection and clinical management of rifampicin-resistant tuberculosis, particularly in regions with a high burden of TB-HIV co-infection.
Tuberculosis (TB) continues to pose a significant public health challenge. An effective immune response against Mycobacterium tuberculosis (M.tb) is widely dependent on T cell memory responses, particularly in Latent tuberculosis infection (LTBI) and active tuberculosis disease (ATB). We quantified and phenotypically characterized peripheral blood mononuclear cells (PBMCs) from Southern Thai cohort after stimulation with established M.tb specific antigen: PPD and novel antigens: IrtA, PE9 and PPE68. We compared immune responses in 60 individuals (ATB n = 20, LTBI n = 20 and healthy controls (HC) n = 20) using flow cytometry and Enzyme linked Immunospot (ELISpot) assays. PPD induced the strongest IFN-γ responses across all groups. PPE68 demonstrated the highest immunogenicity among the novel antigens, inducing stronger IFN-γ responses. PE9 uniquely distinguished disease states by showing significantly reduced CD4+ TNF-α production in ATB and LTBI. PD-1 expression was markedly elevated on PPD-stimulated CD4+ T cells in ATB and LTBI, reflecting antigen load, T cell activation and/or exhaustion, whereas PE9 induced higher PD-1 expression in HC. These findings highlight the distinct immune signatures elicited by classical and novel M.tb antigens, which support further evaluation for future diagnostic or biomarker applications.
The diagnosis of pleural tuberculosis (Pl-TB) remains challenging. Histopathological analysis and pathogen detection in pleural biopsies are informative but limited. We investigated differentially expressed proteins and metabolites in pleural effusions from patients with Pl-TB, malignancies, and other pathologies. A proteomic analysis of pooled pleural effusions identified 45 proteins exclusively detected or upregulated in Pl-TB samples, many linked to infectious processes. Conversely, 18 proteins were uniquely found or upregulated in malignant pleural effusions, mainly associated with detoxification and hemostasis. To validate these findings, we employed targeted proteomics in individual samples. Eight proteins were validated: S100-A9, histone H4, insulin-like growth factor-binding protein 2, fibrinogen beta chain, ficolin-3, immunoglobulin heavy constant alpha 1, sulfhydryl oxidase 1, and histidine-rich glycoprotein. Additionally, NMR-based metabolomics identified 13 metabolites with differential abundance between Pl-TB and non-TB samples. Notably, N-acetyl-glycoprotein and the branched-chain amino acids, alanine and lysine differed between groups. Proteomic and metabolomic analyses revealed distinct molecular profiles between Pl-TB and non-TB patients, despite intra-group variability. To address this, we applied classification models. Histone H4 and alanine consistently emerged as discriminative features. Overall, this study provides novel insights into the molecular landscape of Pl-TB. The combined quantification of proteins and metabolites may improve differential diagnosis, although should be further validated in larger, independent cohorts before clinical application.
