Biomarkers For Tuberculosis Research Articles

Host blood protein biomarkers to screen for tuberculosis disease: a systematic review and meta-analysis.

To our knowledge, this is the first comprehensive systematic review of host blood protein biomarkers for tuberculosis (TB), and we identified promising biomarkers for a TB screening test.

Indole Propionic Acid (IPA), A Gut Microbiota-Derived Metabolite, in Active Pulmonary Tuberculosis (TB) Infection: A Case Control Study

Introduction: A metabolomics study revealed that the tryptophan (Trp) pathway is upregulated in tuberculosis (TB) infection. Indole propionic acid (IPA) is a gut microbiota-derived tryptophan metabolite with antimycobacterial properties through TrpE inhibition and as ligand for AhR in in vitro and in vivo studies. TB infection is associated with gut dysbiosis. However, plasma IPA levels and related factors in active TB patients have not yet been explored. This study aimed to determine the differences and correlations between plasma IPA levels and patient characteristics (age, gender, BMI and GeneXpert result), IPA-producing gut microbiota (Clostridium sporogenes, Lactobacillus sp., and Peptostreptococcus anaerobius), and IFN-γ concentrations in active TB patients and healthy subjects. Materials and methods: A case-control study was performed in 29 active TB patients and 30 healthy controls (HCs) in Aceh, Indonesia. The plasma IPA and IFN-γ levels were measured by ELISA, and the relative abundance of gut microbiota was determined by quantitative PCR (qPCR). The results and discussion: Increased plasma IPA levels (median (IQR) of 22.2 pmol/L (21.3 - 23.9) vs. 18.9 pmol/L (17 - 22.8), p 0.000) were associated with active TB according to the adjusted model (AOR 1.36 (95 % CI 0.37 - 5.1)). Increase of plasma IPA level in higher mycobacterial load patients was found. Higher plasma IPA was positively associated with female, normo- and overweight status, and higher relative abundance of C. sporogenes. The metabolite could be used to discriminate active TB disease at a cutoff of 21.40 pmol/L (72 % sensitivity, 70 % specificity and AUC 0.77). Dysbiosis in IPA-producing bacteria was showed in active TB patients. Conclusion: Plasma IPA could be considered as TB biomarker, and it may also influence disease progression. Future works are needed to validate plasma IPA as biomarker in LTBI and other respiratory infection, as well as its role as biomarker of treatment monitoring response. HIGHLIGHTS The upregulation of the tryptophan (Trp) pathway in tuberculosis infection. Indole propionic acid (IPA) is a Trp metabolite with antimycobacterial properties Higher plasma IPA levels were found in TB patients than in healthy subjects. Dysbiosis of several IPA-producing gut microbiota was revealed in this study. GRAPHICAL ABSTRACT

Combining bioinformatics and machine learning to identify diagnostic biomarkers of TB associated with immune cell infiltration

ObjectiveThe asymptomatic nature of tuberculosis (TB) during its latent phase, combined with limitations in current diagnostic methods, makes accurate diagnosis challenging. This study aims to identify TB diagnostic biomarkers by integrating gene expression screening with machine learning, evaluating their diagnostic potential and correlation with immune cell infiltration. MethodsWe analyzed GSE19435, GSE19444, and GSE54992 datasets to identify differentially expressed genes (DEGs). GO and KEGG enrichment characterized gene functions. Three machine learning algorithms identified potential biomarkers, validated with GSE83456, GSE62525, and RT-qPCR on clinical samples. Immune cell infiltration was analyzed and verified with blood data. Results249 DEGs were identified, with PDE7A and DOK3 emerging as potential biomarkers. RT-qPCR confirmed their expression, showing AUCs above 0.75 and a combined AUC of 0.926 for TB diagnosis. Immune infiltration analysis revealed strong correlations between PDE7A, DOK3, and immune cells. ConclusionPDE7A and DOK3 show strong diagnostic potential for TB, closely linked to immune cell infiltration, and may serve as promising biomarkers and therapeutic targets.

Real-world diagnostic accuracy of lipoarabinomannan in three non-sputum biospecimens for pulmonary tuberculosis disease

Development of a non-sputum test using readily-obtainable biospecimens remains a global priority for tuberculosis (TB) control. We quantified lipoarabinomannan (LAM) concentrations, a pathogen biomarker for Mycobacterium tuberculosis, in urine, plasma and serum for real-world diagnostic accuracy of pulmonary TB among people living with and without HIV. We conducted a prospective diagnostic study among adults with TB symptoms in South Africa. We measured LAM concentrations in time-matched urine, plasma and serum with an electrochemiluminescence immunoassay using two capture antibodies (FIND 28 and S4-20). From the completed cohort, we randomly selected 210 participants (2 cases: 1 control) based on sensitivity estimates, and we compared diagnostic accuracy of LAM measurements against the microbiological reference standard. Urine and blood specimens from 210 of 684 adults enrolled were tested for LAM. Among 138TB-positive adults (41% female), median urine LAM was 137pg/mL and 52pg/mL by FIND 28 and S4-20, respectively. Average LAM concentrations were highest in HIV-positive participants with CD4+ T cells <200cells/mm3. Urine LAM by S4-20 achieved diagnostic sensitivity of 62% (95% CI: 53%-70%) and specificity of 99% (95% CI: 96%-100%). Plasma and serum LAM by FIND 28 showed similar sensitivity (70%, 95% CI: 62%-78%) and comparable specificities (90%, 95% CI: 82%-97%; 94%, 95% CI: 88%-99%). Diagnostic sensitivity of urine LAM by S4-20 was higher among participants without HIV (41%, 95% CI: 24%-61%) compared to HIV-positive participants with CD4 ≥200cells/mm3 (20%, 95% CI: 8%-39%). Detection of LAM was achievable in non-sputum specimens for pulmonary TB, but additional analyte concentration or signal amplification may be required to achieve diagnostic accuracy targets. Bill and Melinda Gates Foundation.

Quantum Dot-Based Nanosensors for In Vitro Detection of Mycobacterium tuberculosis.

Despite the existing effective treatment methods, tuberculosis (TB) is the second most deadly infectious disease, its carriers in the latent and active phases accounting for more than 20% of the world population. An effective method for controlling TB and reducing TB mortality is regular population screening aimed at diagnosing the latent form of TB and taking preventive and curative measures. Numerous methods allow diagnosing TB by directly detecting Mycobacterium tuberculosis (M.tb) biomarkers, including M.tb DNA, proteins, and specific metabolites or antibodies produced by the host immune system in response to M.tb. PCR, ELISA, immunofluorescence and immunochemical analyses, flow cytometry, and other methods allow the detection of M.tb biomarkers or the host immune response to M.tb by recording the optical signal from fluorescent or colorimetric dyes that are components of the diagnostic systems. Current research in biosensors is aimed at increasing the sensitivity of detection, a promising approach being the use of fluorescent quantum dots as brighter and more photostable optical tags. Here, we review current methods for the detection of M.tb biomarkers using quantum dot-based nanosensors and summarize data on the M.tb biomarkers whose detection can be made considerably more sensitive by using these sensors.

Integrating untargeted and targeted LC-MS-based metabolomics to identify the serum metabolite biomarkers for tuberculosis.

Given the limitations of untargeted metabolomics in precise metabolite quantification, our current research employed a novel approach by integrating untargeted and targeted metabolomics utilizing ultra-high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) to analyze the metabolic profile and potential biomarkers for tuberculosis (TB). A cohort of 36 TB patients and 36 healthy controls (HC) was enlisted to obtain serum samples. Multivariate pattern recognition and univariate statistical analysis were employed to screen and elucidate the differential metabolites, whereas dot plots and receiver operating characteristic (ROC) curves were established for the identification of potential biomarkers of TB. The results indicated a distinct differentiation between the two groups, identifying 99 metabolites associated with five primary metabolic pathways in relation to TB. Of these, 19 metabolites exhibited high levels of sensitivity and specificity, as evidenced by the area under curve values approaching 1. Following targeted quantitative analysis, three potential metabolites, namely, L-asparagine, L-glutamic acid, and arachidonic acid, were demonstrated excellent discriminatory ability as evidenced by the results of the ROC curve, dot plots, and random forest model. Particularly noteworthy was the enhanced diagnostic efficacy of the combination of these three metabolites compared to singular biomarkers, suggesting their potential utility as serum biomarkers for TB diagnosis.

Hybrid Polystyrene-Plasmonic Systems as High Binding Density Biosensing Platforms.

Sensitive, accurate, and early detection of biomarkers is essential for prompt response to medical decisions for saving lives. Some infectious diseases are deadly even in small quantities and require early detection for patients and public health. The scarcity of these biomarkers necessitates signal amplification before diagnosis. Recently, we demonstrated single-molecule-level detection of tuberculosis biomarker, lipoarabinomannan, from patient urine using silver plasmonic gratings with thin plasma-activated alumina. While powerful, biomarker binding density was limited by the surface density of plasma-activated carbonyl groups, that degraded quickly, resulting in immediate use requirement after plasma activation. Therefore, development of stable high density binding surfaces such as high binding polystyrene is essential to improving shelf-life, reducing binding protocol complexity, and expanding to a wider range of applications. However, any layers topping the plasmonic grating must be ultra-thin (<10 nm) for the plasmonic enhancement of adjacent signals. Furthermore, fabricating thin polystyrene layers over alumina is nontrivial because of poor adhesion between polystyrene and alumina. Herein, we present the development of a stable, ultra-thin polystyrene layer on the gratings, which demonstrated 63.8 times brighter fluorescence compared to commercial polystyrene wellplates. Spike protein was examined for COVID-19 demonstrating the single-molecule counting capability of the hybrid polystyrene-plasmonic gratings.

Sex-specific blood-derived RNA biomarkers for childhood tuberculosis

Confirmatory diagnosis of childhood tuberculosis (TB) remains a challenge mainly due to its dependence on sputum samples and the paucibacillary nature of the disease. Thus, only ~ 30% of suspected cases in children are diagnosed and the need for minimally invasive, non-sputum-based biomarkers remains unmet. Understanding host molecular changes by measuring blood-based transcriptomic markers has shown promise as a diagnostic tool for TB. However, the implication of sex contributing to disease heterogeneity and therefore diagnosis remains to be understood. Using publicly available gene expression data (GSE39939, GSE39940; n = 370), we report a sex-specific RNA biomarker signature that could improve the diagnosis of TB disease in children. We found four gene biomarker signatures for male (SLAMF8, GBP2, WARS, and FCGR1C) and female pediatric patients (GBP6, CELSR3, ALDH1A1, and GBP4) from Kenya, South Africa, and Malawi. Both signatures achieved a sensitivity of 85% and a specificity of 70%, which approaches the WHO-recommended target product profile for a triage test. Our gene signatures outperform most other gene signatures reported previously for childhood TB diagnosis.

Tryptophan and Its Derived Metabolites as Biomarkers for Tuberculosis Disease: A Systematic Review

Feasible diagnostic assays are required to detect new tuberculosis (TB) cases and monitor treatment. This study aimed to evaluate evidence on tryptophan (Trp) and its metabolites as proposed biomarkers for TB. Through specific keyword searches, we identified 170 relevant literature sources and included seven publications (from 2013 to 2023). The biomarker used in these studies were indoleamine 2, 3-dioxygenase (IDO) activity, IDO-1 gene expression, and plasma IDO protein, measured using ELISA, liquid chromatography-mass spectrometry, ultraperformance liquid chromatography mass spectrometry, and transcriptional profiling. The studies encompassed a pediatric case-control and six studies involving adults, pregnant women with TB-HIV, and individuals with multidrug-resistant tuberculosis, active TB, and latent TB. The assessment of IDO activity and IDO protein level demonstrated promising performance in distinguishing active TB from controls and in evaluating treatment failure and recurrent cases to controls. Trp and its metabolites fulfilled nearly all of target product profile criteria for detecting active TB. This study highlights the potential of utilizing host Trp and its metabolites as non-sputum-based biomarker for TB infection.

Identification of host immune-related biomarkers in active tuberculosis: A comprehensive analysis of differentially expressed genes

Tuberculosis (TB) is a serious public health issue in India. Numerous molecular mechanisms and immunological responses play significant roles in the pathogenesis of tuberculosis. This study aimed to identify host immune-related biomarkers that are significantly differentially expressed in active TB and that play a vital role in disease progression. The methodology employed in this study included data collection, pre-processing, analysis, and interpretation of the results. Six microarray datasets were used to identify differentially expressed genes (DEGs), and only the common DEGs were used for further downstream analysis, such as hub gene identification, gene ontology, pathway enrichment analysis, and drug-gene interaction analysis. The study identified 1728 DEGs, including 906 upregulated and 822 downregulated genes. Five hub genes were identified that were: STAT1, GBP5, GBP1, FCGR1A, and BATF2. Gene ontology and pathway enrichment revealed that most of the genes were involved in interferon-gamma signaling. In addition, through drug-gene interactions, known drugs have been identified for STAT1, FCGR1A and GBP1. The findings of this study may contribute to early detection and treatment of active TB.

The hsa_circ_0002371/hsa-miR-502-5p/ATG16L1 axis modulates the survival of intracellular Mycobacterium tuberculosis and autophagy in macrophages

Circular RNAs (circRNAs) play a critical role in pathological mechanisms of Mycobacterium tuberculosis (Mtb) and can be used as a new biomarker for active tuberculosis (ATB) diagnosis. Therefore, we identified significantly dysregulated circRNAs in ATB patients and healthy controls (HC) and explored their molecular mechanism. We found that hsa_circ_0002371 was significantly up-regulated in PBMCs of ATB patients and Mycobacterium tuberculosis H37Rv- or Mycobacterium bovis bacillus Calmette Guerin (BCG)-infected THP-1 cells. Functional experiments demonstrated that hsa_circ_0002371 inhibited autophagy in BCG-infected THP-1 cells and promoted intracellular BCG survival rate. In terms of mechanism, hsa_circ_0002371 facilitated the expression of hsa-miR-502-5p, as shown by bioinformatics and dual-luciferase reporter gene analysis, respectively. Notably, hsa-miR-502-5p inhibited autophagy via suppressing autophagy related 16 like 1 (ATG16L1) in BCG-infected macrophages and thus promoting intracellular BCG growth. In summation, hsa_circ_0002371 increased the suppression of hsa-miR-502-5p on ATG16L1 and inhibited autophagy to promote Mtb growth in macrophages. In Conclusion, our data suggested that hsa_circ_0002371 was significantly up-regulated in the PBMCs of ATB patients compared with HC. The hsa_circ_0002371/hsa-miR-502-5p/ATG16L1 axis promoted the survival of intracellular Mtb and inhibited autophagy in macrophages. Our findings suggested hsa_circ_0002371 could act as a potential diagnostic biomarker and therapeutic target.

The levels of soluble CD137 are increased in tuberculosis patients and associated with disease severity and prognosis.

Tuberculosis (TB) was the leading cause of death from a single infectious agent before the coronavirus pandemic. Therefore, it is important to search for severity biomarkers and devise appropriate therapies. A total of 139 pulmonary TB (PTB) patients and 80 healthy controls (HCs) were recruited for plasma soluble CD137 (sCD137) detection through ELISA. Moreover, pleural effusion sCD137 levels were measured in 85 TB patients and 36 untreated lung cancer patients. The plasma cytokine levels in 64 patients with PTB and blood immune cell subpopulations in 68 patients with PTB were analysed via flow cytometry. Blood sCD137 levels were higher in PTB patients (p=0.012) and correlated with disease severity (p=0.0056). The level of sCD137 in tuberculous pleurisy effusion (TPE) was markedly higher than that in malignant pleurisy effusion (p=0.018). Several blood cytokines, such as IL-6 (p=0.0147), IL-8 (p=0.0477), IP-10 (p ≤0.0001) and MCP-1 (p=0.0057), and some laboratory indices were significantly elevated in severe PTB (SE) patients, but the percentages of total lymphocytes (p=0.002) and cytotoxic T cells (p=0.036) were significantly lower in SE patients than in non-SE patients. In addition, the sCD137 level was negatively correlated with the percentage of total lymphocytes (p=0.0008) and cytotoxic T cells (p=0.0021), and PTB patients with higher plasma sCD137 levels had significantly shorter survival times (p=0.0041). An increase in sCD137 is a potential biomarker for severe TB and indicates a poor prognosis.

Circulating cell-free RNA in blood as a host response biomarker for detection of tuberculosis

Tuberculosis (TB) remains a leading cause of death from an infectious disease worldwide, partly due to a lack of effective strategies to screen and triage individuals with potential TB. Whole blood RNA signatures have been tested as biomarkers for TB, but have failed to meet the World Health Organization’s (WHO) optimal target product profiles (TPP). Here, we use RNA sequencing and machine-learning to investigate the utility of plasma cell-free RNA (cfRNA) as a host-response biomarker for TB in cohorts from Uganda, Vietnam and Philippines. We report a 6-gene cfRNA signature, which differentiates TB-positive and TB-negative individuals with AUC = 0.95, 0.92, and 0.95 in test, training and validation, respectively. This signature meets WHO TPPs (sensitivity: 97.1% [95% CI: 80.9-100%], specificity: 85.2% [95% CI: 72.4-100%]) regardless of geographic location, sample collection method and HIV status. Overall, our results identify plasma cfRNA as a promising host response biomarker to diagnose TB.

Multi-cohort analysis reveals immune subtypes and predictive biomarkers in tuberculosis

Tuberculosis (TB) remains a significant global health threat, necessitating effective strategies for diagnosis, prognosis, and treatment. This study employs a multi-cohort analysis approach to unravel the immune microenvironment of TB and delineate distinct subtypes within pulmonary TB (PTB) patients. Leveraging functional gene expression signatures (Fges), we identified three PTB subtypes (C1, C2, and C3) characterized by differential immune-inflammatory activity. These subtypes exhibited unique molecular features, functional disparities, and cell infiltration patterns, suggesting varying disease trajectories and treatment responses. A neural network model was developed to predict PTB progression based on a set of biomarker genes, achieving promising accuracy. Notably, despite both genders being affected by PTB, females exhibited a relatively higher risk of deterioration. Additionally, single-cell analysis provided insights into enhanced major histocompatibility complex (MHC) signaling in the rapid clearance of early pathogens in the C3 subgroup. This comprehensive approach offers valuable insights into PTB pathogenesis, facilitating personalized treatment strategies and precision medicine interventions.

Diagnostic value of lncRNAs LINC00152 and LARS2-AS1 and their regulatory roles in macrophage immune response in tuberculosis

ObjectivesTo determine the usefulness of LINC00152 and LARS2-AS1 as potential biomarkers for latent tuberculosis (LTB) and active tuberculosis (ATB), as well as their effect on Mycobacterium (Mtb) infection. MethodsThe expression levels of LINC00152 and LARS2-AS1 in the health, patients with LTB and ATB were detected by qRT-PCR. The ROC curves were constructed to show their potential as biomarkers. The intracellular survival assays for Mtb and the levels of immune-related cytokines were determined to discover the effect of LINC00152 and LARS2-AS1 on Mtb infection. The relationships of miR-485-5p with LINC00152 and LARS2-AS1 were explored. ResultsLINC00152 and LARS2-AS1 levels were significantly elevated in patients with ATB and LTB, and Mtb-infected macrophages. LINC00152 and LARS2-AS1 can distinguish the LTB from the health and ATB from LTB. LARS2-AS1 and LINC00152 knock-down reduced the intracellular Mtb survival and induced cellular immune response after Mtb challenge. miR-485-5p was a targeting miRNA for LINC00152 and LARS2-AS1. ConclusionsLINC00152 and LARS2-AS1 can be considered as potential biomarkers for tuberculosis disease. LINC00152 and LARS2-AS1 have anti-Mtb effects.

Cost-Effective Whole Transcriptome Sequencing Landscape and Diagnostic Potential Biomarkers in Active Tuberculosis.

Tuberculosis (TB) is a prevalent and severe infectious disease that poses a significant threat to human health. However, it is frequently disregarded as there are not enough quick and accurate ways to diagnose tuberculosis. Here, we develop a strategy for tuberculosis detection to address the challenges, including an experimental strategy, namely, Double Adapter Directional Capture sequencing (DADCSeq), an easily operated and low-cost whole transcriptome sequencing method, and a computational method to identify hub differentially expressed genes as well as the diagnosis of TB based on whole transcriptome data using DADCSeq on peripheral blood mononuclear cells (PBMCs) from active TB and latent TB or healthy control. Applying our approach to create a robust and stable TB multi-mRNA risk probability model (TBMMRP) that can accurately distinguish active and latent TB patients, including active TB and healthy controls in clinical cohorts, this diagnostic biomarker was successfully validated by several independent cross-platform cohorts with favorable performance in differentiating active TB from latent TB or active TB from healthy controls and further demonstrated superior or similar diagnostic accuracy compared to previous diagnostic markers. Overall, we develop a low-cost and effective strategy for tuberculosis diagnosis; as the clinical cohort increases, we can expand to different disease kinds and learn new features through our disease diagnosis strategy.

Distinct TB-antigen stimulated cytokine profiles as predictive biomarkers for unfavorable treatment outcomes in pulmonary tuberculosis.

The assessment of tuberculosis (TB) treatment outcomes predominantly relies on sputum culture conversion status. To enhance treatment management, it is crucial to identify non-sputum-based biomarkers that can predict unfavorable outcomes. Cytokines are widely studied as diagnostic biomarkers for active TB. However, their potential as indicators for unfavorable treatment outcomes remains uncertain. This study was conducted within a well-characterized cohort comprising newly diagnosed patients with drug-sensitive pulmonary TB, confirmed through sputum smear and culture positivity. Our objective was to elucidate the TB antigen-stimulated cytokine profile at pre-treatment and at 2 months into anti-TB treatment (ATT) in patients with unfavorable treatment outcomes (cases, n = 27) in comparison to recurrence-free, microbiologically cured controls (n = 31). Whole blood was stimulated with TB antigens using the QuantiFERON In-tube gold method, and plasma supernatants were subjected to a panel of 14 cytokine measurements. In our study, pre-treatment analysis revealed that eight cytokines (IL-2, IFN-γ, TNF-α, IL-6, IL-10, IL-17A, IL-18, and GM-CSF) were significantly elevated at baseline in cases compared to cured controls, both in unstimulated conditions and following TB antigen (CFP10, ESAT6, and TB7.7) stimulation. A similar pattern was observed at the 2-month mark of ATT, with eight cytokines (IL-2, IL-10, IL-13, IFN-γ, IL-6, IL-12p70, IL-17A, and TNF-α) showing significant differences between the groups. Importantly, no variations were detected following mitogen stimulation, underscoring that these distinctive immune responses are primarily driven by TB-specific antigens. Our findings indicate that individuals with unfavorable TB treatment outcomes display a characteristic cytokine profile distinct from TB-cured patients, even before commencing ATT. Therefore, the levels of specific cytokine pre-treatment and at the 2-month point in the course of treatment may serve as predictive immune markers for identifying individuals at risk of unfavorable TB treatment outcomes, with these responses being predominantly influenced by TB-specific antigens.

Pad Printing of Carbon Electrodes with Argon Plasma Activation as a Simple and Low Temperature Manufacturing Process for Antibody‐Type Biosensors

AbstractIn diagnostic tools, rapid in vitro tests such as COVID‐19 antigen or pregnancy tests are gaining significance for identifying various pathologies or health conditions. This shift contributes to a change in the way diagnostic efforts are carried out, emphasizing decentralized approaches that offer valuable services within communities, yielding long‐term advantages for the healthcare system. Considering the substantial quantity of these tests manufactured and used annually, a straightforward manufacturing process is proposed for highly sensitive carbon electrodes designed for antibody‐type biomarker sensors. This process, utilizing pad printing – an additive, low‐temperature, and cost‐effective method, coupled with plasma activation – has proven the electrodes capability to measure interferon gamma protein, a tuberculosis biomarker. Using electrochemical impedance spectroscopy, the electrodes display high sensitivity and are capable of measuring concentrations from 10 to 1000 pg mL−1 in undiluted serum within an hour. The sensor, utilizing solely a monolayer of antibodies, achieves a performance equivalent to that of a commercial standard sandwich ELISA tested in this study.

Redox biomarkers in asymptomatic latent human tuberculosis: a comparison with active disease.

The latent TB infection (LTBI) is an asymptomatic infection caused by Mycobacterium tuberculosis (M.bt). Previous studies have shown a host-protective role for Heme oxygenase-1 (HO-1) during Mtb infection and an important involvement of Glutathione peroxidase-4 (Gpx4) in the necrotic pathology of the disease. Furthermore, increasing evidence suggested a crucial role for Glutathione in the granulomatous response to M. tb infection, with altered GSH levels associated to decreased host resistance. The aim of this study was to provide additional tools for discriminating the pathologic TB state and the asymptomatic infection. We analyzed the gene expression of HO-1 and Gpx4 enzymes in blood of subjects with LTBI, active TB and healthy controls, and we also measured blood levels of the reduced (GSH) and oxidized (GSSG) forms of glutathione, together with the evaluation of GCL expression, the gene responsible for the GSH de novo synthesis. Our findings highlight a shift of glutathione homeostasis towards a more reducing conditions in LTBI, and a different modulation of GSH-dependent genes and HO-1 expression respect to active TB. This study can provide useful tools to understand the redox background that address the infection toward the asymptomatic or active disease.

Serum exosome tRFs as a promising biomarker for active tuberculosis and latent tuberculosis infection

ObjectiveTo analyse the expression profiles of serum exosome tRFs/tiRNAs and to explore their diagnostic value in tuberculosis (TB) activity. MethodsThe serum exosome tRF/tiRNA profile was analysed using high-throughput sequencing technology in 5 active tuberculosis (ATB) patients, 5 latent tuberculosis infection (LTBI) patients and 5 healthy controls (HCs). Then, serum exosome tRFs/tiRNAs were validated by quantitative real-time polymerase chain reaction (qRT–PCR), and their diagnostic value was evaluated by receiver operating characteristic curve (ROC) and area under the curve (AUC). Finally, bioinformatics analysis was performed to explore and identify the potential biological pathways induced by tRFs/tiRNAs. ResultsThe sequencing results revealed that serum exosome tRF/tiRNA expression profiles were different among ATB patients, LTBI patients and HCs. Three tRFs (tRF-56:75-Trp-CCA-4, tRF-1:22-chrM.Ser-GCT and tRF-56:76-Val-TAC-1-M2) were selected for qRT–PCR validation. The results demonstrated that the expression level of tRF-1-22-chrM.Ser-GCT was upregulated in ATB patients, while tRF-56-75-Trp-CCA-4 was downregulated, which was consistent with the sequencing data. The AUCs of tRF-56:75-Trp-CCA-4 and tRF-1:22-chrM. Ser-GCT were 0.824 and 1.000, respectively, which have significant values in the diagnosis of ATB patients. Moreover, the expression levels of tRF-56:75-Trp-CCA-4 and tRF-1:22-chrM.Ser-GCT and tRF-56:76-Val-TAC-1-M2 in ATB patients and LTBI were different, which indicated that these three tRFs could effectively distinguish ATB patients and LTBI patients. ConclusionOur findings indicate that serum exosome tRFs can be used as potential markers for the diagnosis of ATB and LTBI.