Novel Njweipi Chegou

A large proportion of individuals with tuberculosis (TB) are asymptomatic. The biological and inflammatory underpinnings of asymptomatic TB are unknown and may differ from symptomatic TB. We characterise blood transcriptomic and proteomic profiles in South African community screening vs. health facility-based triage cohorts. Asymptomatic TB shares core transcriptomic and proteomic features with symptomatic TB, including upregulation of innate, interferon and inflammatory pathways and downregulation of T and B cell pathways. Integration of transcriptomic and proteomic data from asymptomatic TB individuals identifies two distinct sub-clusters characterized by higher or lower bacterial burden, blood IFN-γ responses, BMI, and chest radiographic abnormalities, suggesting different disease severity. We identify a new blood transcriptomic signature of asymptomatic TB. However, diagnostic performance of transcriptomic and proteomic markers is weaker for asymptomatic TB than symptomatic TB, suggesting that policy development for community-based, asymptomatic TB screening should not adopt biomarkers developed for symptomatic TB triage without further optimization.

Non-sputum-based tests are urgently needed for rapid tuberculosis (TB) diagnosis. While the World Health Organization (WHO) recommends C-reactive protein (CRP) in serum as a TB screening tool for people living with HIV, it falls short of meeting the minimum target product profile (TPP) criteria for a triage test. We hypothesized that combining CRP with Myeloperoxidase (MPO) as a two-protein signature, would diagnose TB with improved accuracy. Using the Meso Scale Discovery platform, we measured CRP and MPO levels in 109 serum samples from adults presenting with TB-like symptoms at primary healthcare centres in South Africa, Uganda, and The Gambia. Diagnoses were based on clinical, laboratory, and radiological findings. Receiver Operator Characteristic (ROC) curve analysis assessed the biomarkers' diagnostic accuracy. CRP and MPO levels differed significantly between TB and other respiratory diseases (ORD). Individually, CRP and MPO achieved areas under the ROC curve (AUCs) of 0.90 and 0.66, respectively. Combined, the AUC remained 0.90, but sensitivity and specificity improved to 91.3% and 77.8% after leave-one-out cross-validation. MPO only increased CRP sensitivity by 2.2%. Concurrent measurement of MPO may improve the accuracy of CRP when used together as a TB diagnostic signature. However, the evidence from our study was not strong and our preliminary findings require validation in larger studies.

Introduction: CD137 (4-1BB), a member of the tumour necrosis factor (TNF) receptor superfamily, plays a key role in T-cell activation, survival, and cytokine production, functions that are central to immune responses against Mycobacterium tuberculosis . This scoping review brings together current evidence on the clinical relevance of CD137 in tuberculosis (TB), including its potential as a diagnostic, prognostic, and therapeutic target. Methods: This review was conducted in accordance with the PRISMA extension for Scoping Reviews (PRISMA-ScR). Relevant studies on CD137 in TB were identified through database searches and screened using predefined eligibility criteria. Experimental, animal, and human studies reporting on CD137 expression, function, or clinical associations were included. Key information from each study was charted to describe the scope, characteristics, and main findings of the available evidence. Results: We identified ten eligible studies involving in vitro experiments, animal models, and human cohorts. CD137-positive T cells and soluble CD137 (sCD137) levels were consistently elevated in active TB, with some evidence suggesting the ability to distinguish disease states and predict severity. Mechanistic studies show that CD137 modulates cytokine responses, including interferon-gamma (IFN-γ) and TNF-α, and interacts with other immune checkpoints such as programmed cell death protein-1 (PD-1) and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4). Preclinical models have demonstrated that CD137-targeted strategies may enhance mycobacterial control. Although current findings are promising, most studies are small, geographically limited, and exploratory. Discussion: CD137 remains an underexplored immune checkpoint with potential to inform host-directed TB diagnostics and therapies, offering a new angle for precision immunology in high-burden settings. Large-scale, longitudinal studies are needed to define its role in host immunity and determine its translational value.

Background: Anti-tuberculosis (anti-TB) antibiotics alter the gut microbiome, potentially affecting the host physiology and immune response. Here, we investigated the impact of anti-TB antibiotics on host gut microbiota, immune response, and Mtb control. Methods: We pre-treated mice with isoniazid, rifampicin, pyrazinamide, and ethambutol (HRZE) for two months, followed by intranasal Mtb infection five days post-HRZE cessation. HRZE pre-treated mice received faecal microbiota transplants (FMT) or phosphate-buffered sa-line (PBS) pre- and post-infection. Faecal DNA was isolated, and 16S rRNA gene se-quencing was performed. Mycobacterial burden, histology, and immune response were assessed in tissues four weeks post-infection. Results: We observed an enrichment of Bacteroides, Alistipes, Alloprevotella, Paraprevotella, and Colidextribacter, and depletion of Clostridia UCG 014, Roseburia, Ruminococcus, and Rikenellaceae RC9 gut group in HRZE pre-treated Mtb-exposed mice compared to infected mice without HRZE (control group). HRZE pre-treatment followed by Mtb infection was associated with marked ileal histo-morphological damage compared to infection alone. Furthermore, gut microbiota alter-ations in HRZE pre-treated mice were associated with poor control of the mycobacterial burden, reduced frequencies of CD4+ T and CD68+ macrophage cell populations, and altered release of IFN-γ, IL-6, and PD-1. Notably, although not completely, FMT improved ileal features, normalised microbiota taxa abundance, lowered Mtb burden, and rescued impaired immune phenotypes. Conclusions: These data highlight the untoward con-sequences of recent anti-TB antibiotics for host control of subsequent Mtb infection and suggest a potential therapeutic avenue for mitigating the effects of HRZE-induced mi-crobiota dysbiosis through FMT or probiotics-associated host-directed therapies to prevent TB recurrence.

Tuberculous meningitis (TBM) is a severe illness that is predominantly observed in countries with a high burden of tuberculosis. It is primarily found in infants and human immunodeficiency virus (HIV)-infected adults, and, if left untreated, causes irreversible damage to the host’s nerve and brain tissue, often leading to mortality. Current methods of TBM detection relies on cerebrospinal fluid (CSF) culture, which may only yield results in up to 6 weeks, is not very sensitive, and requires a biological safety level III laboratory to conduct. Other detection methods are equally not very sensitive and laborious. This research investigates the detection of interferon-gamma (IFN-γ) protein biomarker using fluoroimmunoassay with an optical biosensor and a custom-manufactured chip. The glass-surface of the chip was treated with 3-aminopropyltriethoxysilane (APTES) and incubated with glutaraldehyde to prepare for immobilization, after which a sandwich ELISA format was used to perform a dilution series by immobilizing the capture antibody, IFN-γ protein, and fluorescein isothiocyanate (FITC)-stained detection antibody onto the chip. The optical biosensor excited the FITC-stained antibodies to capture the emission light at multiple exposures, which were then merged to create a high dynamic range (HDR) image for image processing. The results from the optical biosensor were verified with a Zeiss LSM780 confocal microscope (Carl Zeiss (Pty) Limited, Cape Town, South Africa). The system demonstrated the capability to rapidly identify the biomarker, detect the binding sites, and quantify IFN-γ in blood serum. This fluorescent optical sensor proposes a possible approach for the development of a point-of-care system for TBM, providing a quicker and simpler method for the early detection of TBM.

Background: We explored the underlying mechanisms that may drive Post-tuberculosis (TB) lung disease, a multifactorial, heterogenous, and prevalent disease. Methods: Extensive clinical phenotyping through fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)-computed tomography (CT) scans, pulmonary function testing, and symptom and quality of life questionnaires, was performed on a cohort of 48 adults who completed TB treatment within 6 months prior. Immunological characteristics of paired blood- and bronchoalveolar lavage fluid (BALF)-derived immune cells were assessed by multiplex bead-based immunoassay, ELISA and flow cytometry. Results: There was agreement between measures of inflammation on PET, the severity of anatomical abnormalities on CT, and pulmonary function testing. However, of these, only PET was associated with exercise tolerance and symptom scores. Measures of radiologic extent (total glycolytic activity and SUVmax on PET, and segments involved on CT) also correlated with proteins detected in blood that implicate Type 1 (IFN-γ, TNFα, IL-12) and Type 2 (IL-4, IL-33) responses, ongoing remodelling of lung tissue (MMPs), airways and vasculature (VEGF), as well as subsets of activated CD8 ⁺ and CD4 ⁺ T-cells. Conclusion: The radiologic extent of structural post-TB lung involvement is associated with a range of impaired lung function measures and immunological dysregulation. Our findings suggest that obstructive and restrictive lung pathology due to pulmonary tuberculosis do not occur in opposition but rather point towards a mixed pathology in most TB survivors.

Background: Multiple host blood transcriptional signatures have been developed as non-sputum triage tests for tuberculosis (TB). We aimed to compare the diagnostic performance of 20 blood transcriptomic TB signatures for differentiating between symptomatic patients who have TBversusother respiratory diseases (ORD).Methods: As part of a nested case–control study, individuals presenting with respiratory symptoms at primary healthcare clinics in Ethiopia, Malawi, Namibia, Uganda, South Africa and The Gambia were enrolled. TB was diagnosed based on clinical, microbiological and radiological findings. Transcriptomic signatures were measured in whole blood using microfluidic real-time quantitative PCR. Diagnostic performance was benchmarked against the World Health Organization Target Product Profile (TPP) for a non-sputum TB triage test.Results: Among 579 participants, 158 had definite, microbiologically confirmed TB, 32 had probable TB, while 389 participants had ORD. Nine signatures differentiated between ORD and TB with equivalent performance (Satproedprai7: area under the curve 0.83 (95% CI 0.79–0.87); Jacobsen3: 0.83 (95% CI 0.79–0.86); Suliman2: 0.82 (95% CI 0.78–0.86); Roe1: 0.82 (95% CI 0.78–0.86); Kaforou22: 0.82 (95% CI 0.78–0.86); Sambarey10: 0.81 (95% CI 0.77–0.85); Duffy9: 0.81 (95% CI 0.76–0.86); Gliddon3: 0.8 (95% CI 0.75–0.85); Suliman4 0.79 (95% CI 0.75–0.84)). Benchmarked against a 90% sensitivity, these signatures achieved specificities between 44% (95% CI 38–49%) and 54% (95% CI 49–59%), not meeting the TPP criteria. Signature scores significantly varied by HIV status and country. In country-specific analyses, several signatures, such as Satproedprai7 and Penn-Nicholson6, met the minimal TPP criteria for a triage test in Ethiopia, Malawi and South Africa.Conclusion: No signatures met the TPP criteria in a pooled analysis of all countries, but several signatures met the minimum criteria for a non-sputum TB triage test in some countries.

Background Several host blood transcriptomic signatures have shown promise as tuberculosis (TB) diagnostic candidates, supporting the use of such biomarkers in prototype RNA-based point-of-care tests. Further validation of these signatures across different clinical and endemic settings in relevant patient cohorts is required to ascertain their global applicability. We aimed to evaluate the accuracies of published TB transcriptomic signatures in discriminating TB disease from lower respiratory tract infections (LRI) and latent tuberculosis infection (LTBI) in a low-burden hospital setting. Methods We evaluated the accuracy of 20 candidate blood transcriptomic TB signatures in diagnosing TB in 86 individuals (18 TB, 19 LRI, and 49 LTBI) recruited at Oslo University Hospital, Norway. Gene expression was measured using the fluidigm microfluidic qRT-PCR platform on Paxgene blood RNA samples collected at inclusion. The diagnostic performance of the signatures was assessed by area under the receiver operating characteristic curve (AUC-ROC). Results When a head-to-head comparison of the accuracies of the signatures was made between the study groups (TB vs LRI and TB vs LTBI) similar diagnostic performance was observed for the Sweeney 3-, Francisco 2-, Gjøen 7-, and Roe 3- gene signatures (AUC between 0.78 and 0.89). GBP1 and GBP5 were the most accurate individual genes (AUC ≥ 0.80), differentiating TB patients from individuals with LRI and LTBI. However, new 3- and 5-gene combinations, improved the accuracy in distinguishing TB from LRI (AUC=1.00, Sensitivity and specificity of 100%) and TB from LTBI (AUC=0.99, Sensitivity = 93.3%, Specificity = 97.9%), respectively. Conclusion Host blood transcriptomic TB signatures primarily identified in studies from high TB-burden settings showed equivalent diagnostic potential in a low-burden hospital setting. New combinations of transcripts with improved diagnostic accuracy, met the minimal WHO target product profile thresholds for non-sputum-based triage TB tests, and warrant further investigation in larger, prospective, and diverse patient cohorts.