•Twenty-nine host biomarkers were evaluated in urine samples obtained from TB suspects.•Seven individual biomarkers showed potential as promising diagnostic candidates.•A four-marker urinary ...biosignature diagnosed TB with high accuracy in HIV-positive participants.•Urinary inflammatory protein biomarkers are promising as TB diagnostic candidates.
To investigate the potential of host urinary biomarkers as diagnostic candidates for tuberculosis (TB).
Adults self-presenting with symptoms requiring further investigation for TB were enrolled in Cape Town, South Africa. Participants were later classified as having TB or other respiratory diseases (ORD) using results from TB confirmatory tests. The concentrations of 29 analytes were evaluated in urine samples from participants using the Luminex platform, and their diagnostic potential was assessed using standard statistical approaches.
Of the 151 study participants, 34 (22.5%) were diagnosed with TB and 26 (17.2%) were HIV-positive. Seven biomarkers showed potential as TB diagnostic candidates, with accuracy improving (in HIV-positives) when stratified according to HIV status (area under the receiver operating characteristics curve; AUC ≥0.80). In HIV-positive participants, a four-marker biosignature (sIL6R, MMP-9, IL-2Ra, IFN-γ) diagnosed TB with AUC of 0.96, sensitivity of 85.7% (95% confidence interval (CI) 42.1–99.6%), and specificity of 94.7% (95% CI 74.0–99.9%). In HIV-negatives, the most promising was a two-marker biosignature (sIL6R and sIL-2Ra), which diagnosed TB with AUC of 0.76, sensitivity of 53.9% (95% CI 33.4–73.4%), and specificity of 79.6% (95% CI 70.3–87.1%).
Urinary host inflammatory biomarkers possess TB diagnostic potential but may be influenced by HIV infection. The results of this study require validation in larger studies.
Successful TB treatment is hampered by increasing resistance to the two most effective first-line anti-TB drugs, namely isoniazid and rifampicin, thus innovative therapies focused on host processes, ...termed host-directed therapies (HDTs), are promising novel approaches for increasing treatment efficacy without inducing drug resistance. We assessed the ability of Sildenafil, a type-5 phosphodiesterase inhibitor, as a repurposed compound, to serve as HDT target, by counteracting the suppressive effects of myeloid-derived suppressor cells (MDSC) obtained from active TB cases on T-cell responsiveness. We confirm that MDSC suppress non-specific T-cell activation. We also show that Sildenafil treatment fails to reverse the MDSC-mediated suppression of T-cell functions measured here, namely activation and proliferation. The impact of Sildenafil treatment on improved immunity, using the concentration tested here, is likely to be minimal, but further identification and development of MDSC-targeting TB host-directed therapies are warranted.
Early bactericidal activity studies monitor daily sputum bacterial counts in individuals with tuberculosis (TB) for 14 days during experimental drug treatment. The rate of change in sputum bacterial ...load over time provides an informative, but imperfect, estimate of drug activity and is considered a critical step in development of new TB drugs. In this clinical study, 160 participants with TB received isoniazid, pyrazinamide, or rifampicin, components of first-line chemotherapy, and moxifloxacin individually and in combination. In addition to standard bacterial enumeration in sputum, participants underwent 2-deoxy-2-
Ffluoro-d-glucose positron emission tomography and computerized tomography (
FFDG-PET/CT) at the beginning and end of the 14-day drug treatment. Quantitating radiological responses to drug treatment provided comparative single and combination drug activity measures across lung lesion types that correlated more closely with established clinical outcomes when combined with sputum enumeration compared to sputum enumeration alone. Rifampicin and rifampicin-containing drug combinations were most effective in reducing both lung lesion volume measured by CT imaging and lesion-associated inflammation measured by PET imaging. Moxifloxacin was not superior to rifampicin in any measure by PET/CT imaging, consistent with its performance in recent phase 3 clinical trials. PET/CT imaging revealed synergy between isoniazid and pyrazinamide and demonstrated that the activity of pyrazinamide was limited to lung lesion, showing the highest FDG uptake during the first 2 weeks of drug treatment.
FFDG-PET/CT imaging may be useful for measuring the activity of single drugs and drug combinations during evaluation of potential new TB drug regimens before phase 3 trials.
Mycobacterium tuberculosis (M.tb) remains a successful pathogen, causing tuberculosis disease numbers to constantly increase. Although great progress has been made in delineating the disease, the ...host-pathogen interaction is incompletely described. B cells have shown to function as both effectors and regulators of immunity via non-humoral methods in both innate and adaptive immune settings. Here we assessed specific B cell functional interaction following stimulation with a broad range of antigens within the LTBI milieu. Our results indicate that B cells readily produce pro- and anti-inflammatory cytokines (including IL-1β, IL-10, IL-17, IL-21 and TNF-α) in response to stimulation. TLR4 and TLR9 based stimulations achieved the greatest secreted cytokine-production response and BCG stimulation displayed a clear preference for inducing IL-1β production. We also show that the cytokines produced by B cells are implicated strongly in cell-mediated communication and that plasma (memory) B cells (CD19+CD27+CD138+) is the subset with the greatest contribution to cytokine production. Collectively our data provides insight into B cell responses, where they are implicated in and quantifies responses from specific B cell phenotypes. These findings warrant further functional B cell research with a focus on specific B cell phenotypes under conditions of active TB disease to further our knowledge about the contribution of various cell subsets which could have implications for future vaccine development or refined B cell orientated treatment in the health setting.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
There is an urgent need for new, accurate, rapid, and affordable tuberculosis (TB) diagnostic tests. The aim of the present study was to use mass spectrometry to identify new preliminary candidate TB ...diagnostic protein biomarkers in saliva obtained from individuals with TB, and patients with other respiratory diseases (ORD).
Saliva samples were collected from 22 individuals who self-presented with symptoms suggestive of TB as part of a larger TB biomarker project. Purified salivary proteins were subjected to tryptic digestion peptides were analyzed using a QExactive Orbitrap Mass Spectrometer. Data are available via ProteomeXchange with identifier PXD027294. Identified proteins were subjected to gene ontology and ingenuity pathway analysis for functional enrichment analysis.
26 of the 652 identified proteins significantly discriminated individuals with TB from those with ORD after Benjamini Hochberg correction (5% FDR), with five of these proteins diagnosing TB with an AUC ≥ 0.80. A 5-protein biosignature comprising of P01011, Q8NCW5, P28072, A0A2Q2TTZ9, and Q99574 diagnosed TB with an AUC of 1.00 (95% CI, 1.00–1.00), sensitivity of 100% (95% CI, 76.2–100%) and specificity of 90.9% (95% CI, 58.7–99.8%) after leave-one-out cross validation.
We identified novel candidate salivary protein biomarkers and biosignatures with strong potential as TB diagnostic candidates. Our results are preliminary and require validation in larger studies.
The development of a non-sputum-based, point-of-care diagnostic test for tuberculosis (TB) is a priority in the global effort to combat this disease, particularly in resource-constrained settings. ...Previous studies have identified host biomarker signatures which showed potential, but there is a need to validate and refine these for development as a test. We recruited 1,403 adults presenting with symptoms suggestive of pulmonary TB at primary healthcare clinics in six countries from West, East and Southern Africa. Of the study cohort, 326 were diagnosed with TB and 787 with other respiratory diseases, from whom we randomly selected 1005 participants. Using Luminex
technology, we measured the levels of 20 host biomarkers in serum samples which we used to evaluate the diagnostic accuracy of previously identified and novel bio-signatures. Our previously identified seven-marker bio-signature did not perform well (sensitivity: 89%, specificity: 60%). We also identified an optimal, two-marker bio-signature with a sensitivity of 94% and specificity of 69% in patients with no history of previous TB. This signature performed slightly better than C-reactive protein (CRP) alone. The cut-off value for a positive diagnosis differed for human immuno-deficiency virus (HIV)-positive and -negative individuals. Notably, we also found that no signature was able to diagnose TB adequately in patients with a prior history of the disease. We have identified a two-marker, pan-African bio-signature which is more robust than CRP alone and meets the World Health Organization (WHO) target product profile requirements for a triage test in both HIV-negative and HIV-positive individuals. This signature could be incorporated into a point-of-care device, greatly reducing the necessity for expensive confirmatory diagnostics and potentially reducing the number of cases currently lost to follow-up. It might also potentially be useful with individuals unable to provide sputum or with paucibacillary disease. We suggest that the performance of TB diagnostic signatures can be improved by incorporating the HIV-status of the patient. We further suggest that only patients who have never had TB be subjected to a triage test and that those with a history of previous TB be evaluated using more direct diagnostic techniques.
(Mtb) is extremely recalcitrant to antimicrobial chemotherapy requiring 6 months to treat drug-sensitive tuberculosis (TB). Despite this, 4-10% of cured patients will develop recurrent disease within ...12 months after completing therapy. Reasons for relapse in cured TB patients remains speculative, attributed to both pathogen and host factors. Populations of dormant bacilli are hypothesized to cause relapse in initially cured TB patients however, development of tests to convincingly demonstrate their presence at the end of anti-TB treatment has been challenging. Previous studies have indicated the utility of culture filtrate supplemented media (CFSM) to detect differentially culturable tubercle bacilli (DCTB). Here, we show that 3/22 of clinically cured patients retained DCTB in induced sputum and bronchoalveolar lavage fluid (BALF), with one DCTB positive patient relapsing within the first year of completing therapy. We also show a correlation of DCTB status with "unresolved" end of treatment FDG PET-CT imaging. Additionally, 19 end of treatment induced sputum samples from patients not undergoing bronchoscopy were assessed for DCTB, identifying a further relapse case with DCTB. We further show that induced sputum is a less reliable source for the DCTB assay at the end of treatment, limiting the utility of this assay in a clinical setting. We next investigated the host proteome at the site of disease (BALF) using multiplexed proteomic analysis and compared these to active TB cases to identify host-specific factors indicative of cure. Distinct signatures stratified active from cured TB patients into distinct groups, with a DCTB positive, subsequently relapsing, end of treatment patient showing a proteomic signature closer to active TB disease than cure. This exploratory study offers evidence of live Mtb, undetectable with conventional culture methods, at the end of clinically successful treatment and putative host protein biomarkers of active disease and cure. These findings have implications for the assessment of true sterilizing cure in TB patients and opens new avenues for targeted approaches to monitor treatment response.
Myeloid-derived suppressor cells (MDSC) have been identified in the peripheral blood and granulomas of patients with active TB disease, but their phenotype-, function-, and immunosuppressive ...mechanism- spectrum remains unclear. Importantly, the frequency and signaling pathways of MDSC at the site of disease is unknown with no indication how this compares to MDSC identified in peripheral blood or to those of related myeloid counterparts such as alveolar macrophages and monocytes. Most phenotypic and functional markers have been described in oncological studies but have not yet been validated in TB. Using a panel of 43 genes selected from pathways previously shown to contribute to tumor-derived MDSC, we set out to evaluate if the expression of these additional functional markers and properties may also be relevant to TB-derived MDSC. Differential expression was investigated between MDSC, alveolar macrophages and monocytes enriched from bronchoalveolar lavage fluid and peripheral blood of patients with active TB, patients with other lung diseases (OLD). Results demonstrated that anatomical compartments may drive compartment-specific immunological responses and subsequent MDSC immunosuppressive functions, demonstrated by the observation that MDSC and/or monocytes from PB alone can discriminate,
hierarchical clustering, between patients with active TB disease and OLD. Our data show that the gene expression patterns of MDSC in peripheral blood and bronchoalveolar lavage fluid do not cluster according to disease states (TB vs OLD). This suggests that MDSC from TB patients may display similar gene expression profiles to those found for MDSC in cancer, but this needs to be validated in a larger cohort. These are important observations for TB research and may provide direction for future studies aimed at repurposing and validating cancer immunotherapies for use in TB.
To improve tuberculosis (TB) diagnosis, the World Health Organisation (WHO) has called for a non-sputum based triage test to focus TB testing on people with a high likelihood of having active ...pulmonary tuberculosis (TB). Various host or pathogen biomarker-based testing devices are in design stage and require validity assessment. Host biomarkers have shown promise to accurately rule out active TB, but further research is required to determine generalisability. The TriageTB diagnostic test study aims to assess the accuracy of diagnostic test candidates, as well as field-test, finalise the design and biomarker signature, and validate a point-of-care multi-biomarker test (MBT).
This observational diagnostic study will evaluate sensitivity and specificity of biomarker-based diagnostic candidates including the MBT and Xpert® TB Fingerstick cartridge compared with a gold-standard composite TB outcome classification defined by symptoms, sputum GeneXpert® Ultra, smear and culture, radiological features, response to TB therapy and presence of an alternative diagnosis. The study will be conducted in research sites in South Africa, Uganda, The Gambia and Vietnam which all have high TB prevalence. The two-phase design allows for finalisation of the MBT in Phase 1 in which candidate host proteins will be evaluated on stored serum from Asia, South Africa and South America and on fingerstick blood from 50 newly recruited participants per site. The MBT test will then be locked down and validated in Phase 2 on 250 participants per site.
By targeting confirmatory TB testing to those with a positive triage test, 75% of negative GXPU may be avoided, thereby reducing diagnostic costs and patient losses during the care cascade. This study builds on previous biomarker research and aims to identify a point-of-care test meeting or exceeding the minimum World Health Organisation target product profile of a 90% sensitivity and 70% specificity. Streamlining TB testing by identifying individuals with a high likelihood of TB should improve TB resources use and, in so doing, improve TB care.
NCT04232618 (clinicaltrials.gov) Date of registration: 16 January 2020.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Performance of blood transcriptomic tuberculosis (TB) signatures in longitudinal studies and effects of TB-preventive therapy and coinfection with HIV or respiratory organisms on transcriptomic ...signatures has not been systematically studied.
We evaluated longitudinal kinetics of an 11-gene blood transcriptomic TB signature, RISK11, and effects of TB-preventive therapy (TPT) and respiratory organisms on RISK11 signature score, in HIV-uninfected and HIV-infected individuals.
RISK11 was measured in a longitudinal study of RISK11-guided TPT in HIV-uninfected adults, a cross-sectional respiratory organisms cohort, or a longitudinal study in people living with HIV (PLHIV). HIV-uninfected RISK11
participants were randomized to TPT or no TPT; RISK11
participants received no TPT. PLHIV received standard-of-care antiretroviral therapy and TPT. In the cross-sectional respiratory organisms cohort, viruses and bacteria in nasopharyngeal and oropharyngeal swabs were quantified by real-time quantitative PCR.
RISK11
status was transient in most of the 128 HIV-negative participants with longitudinal samples; more than 70% of RISK11
participants reverted to RISK11
by 3 months, irrespective of TPT. By comparison, reversion from a RISK11
state was less common in 645 PLHIV (42.1%). Non-HIV viral and nontuberculous bacterial organisms were detected in 7.2% and 38.9% of the 1,000 respiratory organisms cohort participants, respectively, and among those investigated for TB, 3.8% had prevalent disease. Median RISK11 scores (%) were higher in participants with viral organisms alone (46.7%), viral and bacterial organisms (42.8%), or prevalent TB (85.7%) than those with bacterial organisms other than TB (13.4%) or no organisms (14.2%). RISK11 could not discriminate between prevalent TB and viral organisms.
Positive RISK11 signature status is often transient, possibly due to intercurrent viral infection, highlighting potentially important challenges for implementation of these biomarkers as new tools for TB control.
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