Publications by authors named "Katharina Ronacher"

56 Publications

Mycobacterium tuberculosis-stimulated whole blood culture to detect host biosignatures for tuberculosis treatment response.

Tuberculosis (Edinb) 2021 Apr 10;128:102082. Epub 2021 Apr 10.

DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Host markers to monitor the response to tuberculosis (TB) therapy hold some promise. We evaluated the changes in concentration of Mycobacterium tuberculosis (M.tb)-induced soluble biomarkers during early treatment for predicting short- and long-term treatment outcomes. Whole blood samples from 30 cured and 12 relapsed TB patients from diagnosis, week 1, 2, and 4 of treatment were cultured in the presence of live M.tb for seven days and patients followed up for 24 weeks after the end of treatment. 57 markers were measured in unstimulated and antigen-stimulated culture supernatants using Luminex assays. Top performing multi-variable models at diagnosis using unstimulated values predicted outcome at 24 months after treatment completion with a sensitivity of 75.0% (95% CI, 42.8-94.5%) and specificity of 72.4% (95% CI, 52.8-87.3%) in leave-one-out cross validation. Month two treatment responder classification was correctly predicted with a sensitivity of 79.2% (95% CI, 57.8-92.9%) and specificity of 92.3% (95% CI, 64.0-99.8%). This study provides evidence of the early M.tb-specific treatment response in TB patients but shows that the observed unstimulated marker models are not outperformed by stimulated marker models. Performance of unstimulated predictive host marker signatures is promising and requires validation in larger studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tube.2021.102082DOI Listing
April 2021

The Peripheral Blood Transcriptome Is Correlated With PET Measures of Lung Inflammation During Successful Tuberculosis Treatment.

Front Immunol 2020 10;11:596173. Epub 2021 Feb 10.

Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Stellenbosch University, Cape Town, South Africa.

Pulmonary tuberculosis (PTB) is characterized by lung granulomas, inflammation and tissue destruction. Here we used within-subject peripheral blood gene expression over time to correlate with the within-subject lung metabolic activity, as measured by positron emission tomography (PET) to identify biological processes and pathways underlying overall resolution of lung inflammation. We used next-generation RNA sequencing and [F]FDG PET-CT data, collected at diagnosis, week 4, and week 24, from 75 successfully cured PTB patients, with the [F]FDG activity as a surrogate for lung inflammation. Our linear mixed-effects models required that for each individual the slope of the line of [F]FDG data in the outcome and the slope of the peripheral blood transcript expression data correlate, i.e., the slopes of the outcome and explanatory variables had to be similar. Of 10,295 genes that changed as a function of time, we identified 639 genes whose expression profiles correlated with decreasing [F]FDG uptake levels in the lungs. Gene enrichment over-representation analysis revealed that numerous biological processes were significantly enriched in the 639 genes, including several well known in TB transcriptomics such as platelet degranulation and response to interferon gamma, thus validating our novel approach. Others not previously associated with TB pathobiology included smooth muscle contraction, a set of pathways related to mitochondrial function and cell death, as well as a set of pathways connecting transcription, translation and vesicle formation. We observed up-regulation in genes associated with B cells, and down-regulation in genes associated with platelet activation. We found 254 transcription factor binding sites to be enriched among the 639 gene promoters. In conclusion, we demonstrated that of the 10,295 gene expression changes in peripheral blood, only a subset of 639 genes correlated with inflammation in the lungs, and the enriched pathways provide a description of the biology of resolution of lung inflammation as detectable in peripheral blood. Surprisingly, resolution of PTB inflammation is positively correlated with smooth muscle contraction and, extending our previous observation on mitochondrial genes, shows the presence of mitochondrial stress. We focused on pathway analysis which can enable therapeutic target discovery and potential modulation of the host response to TB.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2020.596173DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7902901PMC
February 2021

GPR183 Regulates Interferons, Autophagy, and Bacterial Growth During Infection and Is Associated With TB Disease Severity.

Front Immunol 2020 6;11:601534. Epub 2020 Nov 6.

Translational Research Institute-Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia.

Oxidized cholesterols have emerged as important signaling molecules of immune function, but little is known about the role of these oxysterols during mycobacterial infections. We found that expression of the oxysterol-receptor GPR183 was reduced in blood from patients with tuberculosis (TB) and type 2 diabetes (T2D) compared to TB patients without T2D and was associated with TB disease severity on chest x-ray. GPR183 activation by 7,25-dihydroxycholesterol (7,25-OHC) reduced growth of (Mtb) and BCG in primary human monocytes, an effect abrogated by the GPR183 antagonist GSK682753. Growth inhibition was associated with reduced IFN-β and IL-10 expression and enhanced autophagy. Mice lacking GPR183 had significantly increased lung Mtb burden and dysregulated IFNs during early infection. Together, our data demonstrate that GPR183 is an important regulator of intracellular mycobacterial growth and interferons during mycobacterial infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2020.601534DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7677584PMC
November 2020

Screening diabetes mellitus patients for pulmonary tuberculosis: a multisite study in Indonesia, Peru, Romania and South Africa.

Trans R Soc Trop Med Hyg 2020 Oct 28. Epub 2020 Oct 28.

Centre for International Health, University of Otago Medical School, University of Otago, Dunedin, New Zealand.

Background: Diabetes mellitus (DM) patients are three times more likely to develop tuberculosis (TB) than the general population. Active TB screening in people with DM is part of a bidirectional approach. The aim of this study was to conduct pragmatic active TB screening among DM patients in four countries to inform policy.

Methods: DM patients were recruited in Indonesia (n=809), Peru (n=600), Romania (n=603) and South Africa (n=51). TB cases were diagnosed using an algorithm including clinical symptoms and chest X-ray. Presumptive TB patients were examined with sputum smear and culture.

Results: A total of 171 (8.3%) individuals reported ever having had TB (South Africa, 26%; Indonesia, 12%; Peru, 7%; Romania, 4%), 15 of whom were already on TB treatment. Overall, 14 (0.73% [95% confidence interval 0.40 to 1.23]) TB cases were identified from screening. Poor glucose control, smoking, lower body mass index, education and socio-economic status were associated with newly diagnosed/current TB. Thirteen of the 14 TB cases diagnosed from this screening would have been found using a symptom-based approach.

Conclusions: These data support the World Health Organization recommendation for routine symptom-based screening for TB in known DM patients in high TB-burden countries. DM patients with any symptoms consistent with TB should be investigated and diagnostic tools should be easily accessible.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/trstmh/traa100DOI Listing
October 2020

High glucose levels increase influenza-associated damage to the pulmonary epithelial-endothelial barrier.

Elife 2020 07 22;9. Epub 2020 Jul 22.

School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Australia.

Diabetes mellitus is a known susceptibility factor for severe influenza virus infections. However, the mechanisms that underlie this susceptibility remain incompletely understood. Here, the effects of high glucose levels on influenza severity were investigated using an model of the pulmonary epithelial-endothelial barrier as well as an murine model of type II diabetes. we show that high glucose conditions prior to IAV infection increased virus-induced barrier damage. This was associated with an increased pro-inflammatory response in endothelial cells and the subsequent damage of the epithelial junctional complex. These results were subsequently validated . This study provides the first evidence that hyperglycaemia may increase influenza severity by damaging the pulmonary epithelial-endothelial barrier and increasing pulmonary oedema. These data suggest that maintaining long-term glucose control in individuals with diabetes is paramount in reducing the morbidity and mortality associated with influenza virus infections.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7554/eLife.56907DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7392605PMC
July 2020

Impact of Intermediate Hyperglycemia and Diabetes on Immune Dysfunction in Tuberculosis.

Clin Infect Dis 2021 01;72(1):69-78

Tuberculosis Centre and Department of Infection and Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom.

Background: People with diabetes have an increased risk of developing active tuberculosis (TB) and are more likely to have poor TB-treatment outcomes, which may impact on control of TB as the prevalence of diabetes is increasing worldwide. Blood transcriptomes are altered in patients with active TB relative to healthy individuals. The effects of diabetes and intermediate hyperglycemia (IH) on this transcriptomic signature were investigated to enhance understanding of immunological susceptibility in diabetes-TB comorbidity.

Methods: Whole blood samples were collected from active TB patients with diabetes (glycated hemoglobin [HbA1c] ≥6.5%) or IH (HbA1c = 5.7% to <6.5%), TB-only patients, and healthy controls in 4 countries: South Africa, Romania, Indonesia, and Peru. Differential blood gene expression was determined by RNA-seq (n = 249).

Results: Diabetes increased the magnitude of gene expression change in the host transcriptome in TB, notably showing an increase in genes associated with innate inflammatory and decrease in adaptive immune responses. Strikingly, patients with IH and TB exhibited blood transcriptomes much more similar to patients with diabetes-TB than to patients with only TB. Both diabetes-TB and IH-TB patients had a decreased type I interferon response relative to TB-only patients.

Conclusions: Comorbidity in individuals with both TB and diabetes is associated with altered transcriptomes, with an expected enhanced inflammation in the presence of both conditions, but also reduced type I interferon responses in comorbid patients, suggesting an unexpected uncoupling of the TB transcriptome phenotype. These immunological dysfunctions are also present in individuals with IH, showing that altered immunity to TB may also be present in this group. The TB disease outcomes in individuals with IH diagnosed with TB should be investigated further.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cid/ciaa751DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7823074PMC
January 2021

Glycemic Variability in Diabetes Increases the Severity of Influenza.

mBio 2020 03 24;11(2). Epub 2020 Mar 24.

School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia

People with diabetes are two times more likely to die from influenza than people with no underlying medical condition. The mechanisms underlying this susceptibility are poorly understood. In healthy individuals, small and short-lived postprandial peaks in blood glucose levels occur. In diabetes mellitus, these fluctuations become greater and more frequent. This glycemic variability is associated with oxidative stress and hyperinflammation. However, the contribution of glycemic variability to the pathogenesis of influenza A virus (IAV) has not been explored. Here, we used an model of the pulmonary epithelial-endothelial barrier and novel murine models to investigate the role of glycemic variability in influenza severity. , a history of glycemic variability significantly increased influenza-driven cell death and destruction of the epithelial-endothelial barrier. , influenza virus-infected mice with a history of glycemic variability lost significantly more body weight than mice with constant blood glucose levels. This increased disease severity was associated with markers of oxidative stress and hyperinflammation both and Together, these results provide the first indication that glycemic variability may help drive the increased risk of severe influenza in people with diabetes mellitus. Every winter, people with diabetes are at increased risk of severe influenza. At present, the mechanisms that cause this increased susceptibility are unclear. Here, we show that the fluctuations in blood glucose levels common in people with diabetes are associated with severe influenza. These data suggest that glycemic stability could become a greater clinical priority for patients with diabetes during outbreaks of influenza.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/mBio.02841-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7157527PMC
March 2020

Quantitative 18F-FDG PET-CT scan characteristics correlate with tuberculosis treatment response.

EJNMMI Res 2020 Feb 10;10(1). Epub 2020 Feb 10.

Department of Science and Technology/National Research Foundation, Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Council Centre for Tuberculosis Research, Cape Town, South Africa.

Background: There is a growing interest in the use of F-18 FDG PET-CT to monitor tuberculosis (TB) treatment response. Tuberculosis lung lesions are often complex and diffuse, with dynamic changes during treatment and persisting metabolic activity after apparent clinical cure. This poses a challenge in quantifying scan-based markers of burden of disease and disease activity. We used semi-automated, whole lung quantification of lung lesions to analyse serial FDG PET-CT scans from the Catalysis TB Treatment Response Cohort to identify characteristics that best correlated with clinical and microbiological outcomes.

Results: Quantified scan metrics were already associated with clinical outcomes at diagnosis and 1 month after treatment, with further improved accuracy to differentiate clinical outcomes after standard treatment duration (month 6). A high cavity volume showed the strongest association with a risk of treatment failure (AUC 0.81 to predict failure at diagnosis), while a suboptimal reduction of the total glycolytic activity in lung lesions during treatment had the strongest association with recurrent disease (AUC 0.8 to predict pooled unfavourable outcomes). During the first year after TB treatment lesion burden reduced; but for many patients, there were continued dynamic changes of individual lesions.

Conclusions: Quantification of FDG PET-CT images better characterised TB treatment outcomes than qualitative scan patterns and robustly measured the burden of disease. In future, validated metrics may be used to stratify patients and help evaluate the effectiveness of TB treatment modalities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13550-020-0591-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7010890PMC
February 2020

Time-Dependent Changes in Urinary Metabolome Before and After Intensive Phase Tuberculosis Therapy: A Pharmacometabolomics Study.

OMICS 2019 11 15;23(11):560-572. Epub 2019 Oct 15.

Human Metabolomics, North-West University, Potchefstroom, South Africa.

Pharmacometabolomics is a rapidly emerging omics science signaling the convergence of clinical pharmacology, metabolomics, precision medicine, and biomarker research. Tuberculosis (TB) treatment outcomes have complex biological, environmental, and social determinants and thus, represent a promising application of pharmacometabolomics. In samples of 23 patients undergoing intensive phase TB therapy for 4 weeks, we identified drug-induced host-metabolome variations before and at repeated time intervals post-treatment: (1) an overall reduction in the oxidative stress levels over the course of TB treatment; (2) a time-dependent induction and inhibition of several enzymes in response to the drugs (CYP2E1, CYP3A4, alcohol dehydrogenase, and aminocarboxymuconate-semialdehyde decarboxylase), and altered oxidative stress levels (aconitase, formylglycine-generating enzyme, α-ketoglutarate dehydrogenase, and succinate-semialdehyde dehydrogenase); (3) an upregulated urea cycle; and (4) altered insulin production. This is the first study of its kind to indicate changes to the host metabolome in response to intensive TB treatment, at different time intervals during the course of treatment. These results provide new insights into the mechanisms of TB drug metabolism, drug action, and drug-related side effects, thereby paving the way for the development of improved therapeutic approaches for the disease, and perhaps more importantly, also for monitoring treatment progression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/omi.2019.0140DOI Listing
November 2019

Distinct serum biosignatures are associated with different tuberculosis treatment outcomes.

Tuberculosis (Edinb) 2019 09 12;118:101859. Epub 2019 Aug 12.

DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. Electronic address:

Biomarkers for TB treatment response and outcome are needed. This study characterize changes in immune profiles during TB treatment, define biosignatures associated with treatment outcomes, and explore the feasibility of predictive models for relapse. Seventy-two markers were measured by multiplex cytokine array in serum samples from 78 cured, 12 relapsed and 15 failed treatment patients from South Africa before and during therapy for pulmonary TB. Promising biosignatures were evaluated in a second cohort from Uganda/Brazil consisting of 17 relapse and 23 cured patients. Thirty markers changed significantly with different response patterns during TB treatment in cured patients. The serum biosignature distinguished cured from relapse patients and a combination of two clinical (time to positivity in liquid culture and BMI) and four immunological parameters (TNF-β, sIL-6R, IL-12p40 and IP-10) at diagnosis predicted relapse with a 75% sensitivity (95%CI 0.38-1) and 85% specificity (95%CI 0.75-0.93). This biosignature was validated in an independent Uganda/Brazil cohort correctly classifying relapse patients with 83% (95%CI 0.58-1) sensitivity and 61% (95%CI 0.39-0.83) specificity. A characteristic biosignature with value as predictor of TB relapse was identified. The repeatability and robustness of these biomarkers require further validation in well-characterized cohorts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tube.2019.101859DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6839616PMC
September 2019

Diabetes Mellitus Among Pulmonary Tuberculosis Patients From 4 Tuberculosis-endemic Countries: The TANDEM Study.

Clin Infect Dis 2020 02;70(5):780-788

Department of Internal Medicine and Radboud Center of Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands.

Background: Diabetes mellitus (DM) increases active tuberculosis (TB) risk and worsens TB outcomes, jeopardizing TB control especially in TB-endemic countries with rising DM prevalence rates. We assessed DM status and clinical correlates in TB patients across settings in Indonesia, Peru, Romania, and South Africa.

Methods: Age-adjusted DM prevalence was estimated using laboratory glycated hemoglobin (HbA1c) or fasting plasma glucose in TB patients. Detailed and standardized sociodemographic, anthropometric, and clinical measurements were made. Characteristics of TB patients with or without DM were compared using multilevel mixed-effect regression models with robust standard errors.

Results: Of 2185 TB patients (median age 36.6 years, 61.2% male, 3.8% human immunodeficiency virus-infected), 12.5% (267/2128) had DM, one third of whom were newly diagnosed. Age-standardized DM prevalence ranged from 10.9% (South Africa) to 19.7% (Indonesia). Median HbA1c in TB-DM patients ranged from 7.4% (Romania) to 11.3% (Indonesia). Compared to those without DM, TB-DM patients were older and had a higher body mass index (BMI) (P value < .05). Compared to those with newly diagnosed DM, TB patients with diagnosed DM had higher BMI and HbA1c, less severe TB, and more frequent comorbidities, DM complications, and hypertension (P value < .05).

Conclusions: We show that DM prevalence and clinical characteristics of TB-DM vary across settings. Diabetes is primarily known but untreated, hyperglycemia is often severe, and many patients with TB-DM have significant cardiovascular disease risk and severe TB. This underlines the need to improve strategies for better clinical management of combined TB and DM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cid/ciz284DOI Listing
February 2020

Assessment of Validity of a Blood-Based 3-Gene Signature Score for Progression and Diagnosis of Tuberculosis, Disease Severity, and Treatment Response.

JAMA Netw Open 2018 10 5;1(6):e183779. Epub 2018 Oct 5.

Institute for Immunity, Transplantation, and Infection, Stanford University, Stanford, California.

Importance: The World Health Organization identified the need for a non-sputum-based triage test to identify those in need of further tuberculosis (TB) testing.

Objective: To determine whether the 3-gene TB score can be a diagnostic tool throughout the course of TB disease, from latency to diagnosis to treatment response, and posttreatment residual inflammation.

Design, Setting, And Participants: This nested case-control study analyzed the 3-gene TB score in 3 cohorts, each focusing on a different stage of TB disease: (1) the Adolescent Cohort Study profiled whole-blood samples from adolescents with latent Mycobacterium tuberculosis infection, some of which progressed to active TB (ATB), using RNA sequencing; (2) the Brazil Active Screen Study collected whole blood from an actively screened case-control cohort of adult inmates from 2 prisons in Mato Grosso do Sul, Brazil, for ATB from January 2016 to February 2016; and (3) the Catalysis Treatment Response Cohort (CTRC) identified culture-positive adults in primary health care clinics in Cape Town, South Africa, from 2005 to 2007 and collected whole blood for RNA sequencing from patients with ATB at diagnosis and weeks 1, 4, and 24. The CTRC patients also had positron emission tomography-computed tomography scans at diagnosis, week 4, and week 24. Analyses were performed from September 2017 to June 2018.

Main Outcomes And Measures: A 3-gene messenger RNA expression score, measured by quantitative polymerase chain reaction or RNA sequencing, was evaluated for distinguishing the following: individuals who progressed to ATB from those who did not, individuals with ATB from those without, and individuals with slower treatment response during TB therapy.

Results: Patients evaluated in this study included 144 adolescents from the Adolescent Cohort Study (aged 12-18 years; 96 female and 48 male), 81 adult prison inmates from the Brazil Active Screen Study (aged 20-72 years; 81 male), and 138 adult community members from the CTRC (aged 17-64 years; 81 female and 57 male). The 3-gene TB score identified progression from latent M tuberculosis infection to ATB 6 months prior to sputum conversion with 86% sensitivity and 84% specificity (area under the curve [AUC], 0.86; 95% CI, 0.77-0.96) and patients with ATB in the Brazil Active Screen Study cohort (AUC, 0.87; 95% CI, 0.78-0.95) and CTRC (AUC, 0.94; 95% CI, 0.88-0.99). It also identified CTRC patients with failed treatment at the end of treatment (AUC, 0.93; 95% CI, 0.83-1.00). Collectively, across all cohorts, the 3-gene TB score identified patients with ATB with 90% sensitivity, 70% specificity, and 99.3% negative predictive value at 4% prevalence.

Conclusions And Relevance: Across 3 independent prospective cohorts, the 3-gene TB score approaches the World Health Organization target product profile benchmarks for non-sputum-based triage test with high negative predictive value. This gene expression diagnostic approach should be considered for further validation and future implementation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1001/jamanetworkopen.2018.3779DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6324428PMC
October 2018

Diabetes screen during tuberculosis contact investigations highlights opportunity for new diabetes diagnosis and reveals metabolic differences between ethnic groups.

Tuberculosis (Edinb) 2018 12 18;113:10-18. Epub 2018 Aug 18.

DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa; Mater Research Institute - The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia. Electronic address:

Type 2 diabetes (T2D) is a prevalent risk factor for tuberculosis (TB), but most studies on TB-T2D have focused on TB patients, been limited to one community, and shown a variable impact of T2D on TB risk or treatment outcomes. We conducted a cross-sectional assessment of sociodemographic and metabolic factors in adult TB contacts with T2D (versus no T2D), from the Texas-Mexico border to study Hispanics, and in Cape Town to study South African Coloured ethnicities. The prevalence of T2D was 30.2% in Texas-Mexico and 17.4% in South Africa, with new diagnosis in 34.4% and 43.9%, respectively. Contacts with T2D differed between ethnicities, with higher smoking, hormonal contraceptive use and cholesterol levels in South Africa, and higher obesity in Texas-Mexico (p < 0.05). PCA analysis revealed striking differences between ethnicities in the relationships between factors defining T2D and dyslipidemias. Our findings suggest that screening for new T2D in adult TB contacts is effective to identify new T2D patients at risk for TB. Furthermore, studies aimed at predicting individual TB risk in T2D patients, should take into account the heterogeneity in dyslipidemias that are likely to modify the estimates of TB risk or adverse treatment outcomes that are generally attributed to T2D alone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tube.2018.08.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6284235PMC
December 2018

Accuracy of diabetes screening methods used for people with tuberculosis, Indonesia, Peru, Romania, South Africa.

Bull World Health Organ 2018 Nov 27;96(11):738-749. Epub 2018 Aug 27.

Population Health Research Institute, St George's University of London, Cranmer Terrace, London SW17 0RE, England.

Objective: To evaluate the performance of diagnostic tools for diabetes mellitus, including laboratory methods and clinical risk scores, in newly-diagnosed pulmonary tuberculosis patients from four middle-income countries.

Methods: In a multicentre, prospective study, we recruited 2185 patients with pulmonary tuberculosis from sites in Indonesia, Peru, Romania and South Africa from January 2014 to September 2016. Using laboratory-measured glycated haemoglobin (HbA1c) as the gold standard, we measured the diagnostic accuracy of random plasma glucose, point-of-care HbA1c, fasting blood glucose, urine dipstick, published and newly derived diabetes mellitus risk scores and anthropometric measurements. We also analysed combinations of tests, including a two-step test using point-of-care HbA1cwhen initial random plasma glucose was ≥ 6.1 mmol/L.

Findings: The overall crude prevalence of diabetes mellitus among newly diagnosed tuberculosis patients was 283/2185 (13.0%; 95% confidence interval, CI: 11.6-14.4). The marker with the best diagnostic accuracy was point-of-care HbA1c (area under receiver operating characteristic curve: 0.81; 95% CI: 0.75-0.86). A risk score derived using age, point-of-care HbA1c and random plasma glucose had the best overall diagnostic accuracy (area under curve: 0.85; 95% CI: 0.81-0.90). There was substantial heterogeneity between sites for all markers, but the two-step combination test performed well in Indonesia and Peru.

Conclusion: Random plasma glucose followed by point-of-care HbA1c testing can accurately diagnose diabetes in tuberculosis patients, particularly those with substantial hyperglycaemia, while reducing the need for more expensive point-of-care HbA1c testing. Risk scores with or without biochemical data may be useful but require validation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2471/BLT.17.206227DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6239004PMC
November 2018

Author Correction: A multi-cohort study of the immune factors associated with M. tuberculosis infection outcomes.

Nature 2018 12;564(7734):E5

Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA.

The spelling of author Qianting Yang was corrected; the affiliation of author Stephanus T. Malherbe was corrected; and graphs in Fig. 4b and c were corrected owing to reanalysis of the data into the correct timed intervals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41586-018-0635-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6419094PMC
December 2018

IL-22: An Underestimated Player in Natural Resistance to Tuberculosis?

Front Immunol 2018 25;9:2209. Epub 2018 Sep 25.

Infection, Immunity and Metabolism Group, Translational Research Institute, Mater Research Institute and The University of Queensland, Brisbane, QLD, Australia.

Approximately 10% of individuals latently infected with (Mtb) develop active tuberculosis (TB) during their lifetime. Although it is well recognized that T-helper 1 immune responses are crucial for containing latent TB infection, the full array of host factors conferring protective immunity from TB progression are not completely understood. IL-22 is produced by cells of the innate and adaptive immune system including innate lymphoid cells, and natural killer cells as well as T lymphocytes (Th1, Th17, and Th22) and binds to its cognate receptor, the IL-22R1, which is expressed on non-hematopoietic cells such as lung epithelial cells. However, recent studies suggest that Mtb induces expression of the IL-22R1 on infected macrophages and multiple studies have indicated a protective role of IL-22 in respiratory tract infections. Reduced concentrations of circulating IL-22 in active TB compared to latent TB and decreased percentages of Mtb-specific IL-22 producing T cells in TB patients compared to controls designate this cytokine as a key player in TB immunology. More recently, it has been shown that in type 2 diabetes (T2D) and TB co-morbidity serum IL-22 concentrations are further reduced compared to TB patients without co-morbidities. However, whether a causative link between low IL-22 and increased susceptibility to TB and disease severity of TB exists remains to be established. This review summarizes the contribution of IL-22, a potentially under-appreciated key player in natural resistance to TB, at the interface between the immune response to Mtb and the lung epithelium.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2018.02209DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6167461PMC
October 2019

A multi-cohort study of the immune factors associated with M. tuberculosis infection outcomes.

Nature 2018 08 22;560(7720):644-648. Epub 2018 Aug 22.

Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA.

Most infections with Mycobacterium tuberculosis (Mtb) manifest as a clinically asymptomatic, contained state, known as latent tuberculosis infection, that affects approximately one-quarter of the global population. Although fewer than one in ten individuals eventually progress to active disease, tuberculosis is a leading cause of death from infectious disease worldwide. Despite intense efforts, immune factors that influence the infection outcomes remain poorly defined. Here we used integrated analyses of multiple cohorts to identify stage-specific host responses to Mtb infection. First, using high-dimensional mass cytometry analyses and functional assays of a cohort of South African adolescents, we show that latent tuberculosis is associated with enhanced cytotoxic responses, which are mostly mediated by CD16 (also known as FcγRIIIa) and natural killer cells, and continuous inflammation coupled with immune deviations in both T and B cell compartments. Next, using cell-type deconvolution of transcriptomic data from several cohorts of different ages, genetic backgrounds, geographical locations and infection stages, we show that although deviations in peripheral B and T cell compartments generally start at latency, they are heterogeneous across cohorts. However, an increase in the abundance of circulating natural killer cells in tuberculosis latency, with a corresponding decrease during active disease and a return to baseline levels upon clinical cure are features that are common to all cohorts. Furthermore, by analysing three longitudinal cohorts, we find that changes in peripheral levels of natural killer cells can inform disease progression and treatment responses, and inversely correlate with the inflammatory state of the lungs of patients with active tuberculosis. Together, our findings offer crucial insights into the underlying pathophysiology of tuberculosis latency, and identify factors that may influence infection outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41586-018-0439-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6414221PMC
August 2018

Disease characteristics and treatment of patients with diabetes mellitus attending government health services in Indonesia, Peru, Romania and South Africa.

Trop Med Int Health 2018 10 10;23(10):1118-1128. Epub 2018 Sep 10.

Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands.

Objective: To describe the characteristics and management of Diabetes mellitus (DM) patients from low- and middle-income countries (LMIC).

Methods: We systematically characterised consecutive DM patients attending public health services in urban settings in Indonesia, Peru, Romania and South Africa, collecting data on DM treatment history, complications, drug treatment, obesity, HbA1c and cardiovascular risk profile; and assessing treatment gaps against relevant national guidelines.

Results: Patients (median 59 years, 62.9% female) mostly had type 2 diabetes (96%), half for >5 years (48.6%). Obesity (45.5%) and central obesity (females 84.8%; males 62.7%) were common. The median HbA1c was 8.7% (72 mmol/mol), ranging from 7.7% (61 mmol/mol; Peru) to 10.4% (90 mmol/mol; South Africa). Antidiabetes treatment included metformin (62.6%), insulin (37.8%), and other oral glucose-lowering drugs (34.8%). Disease complications included eyesight problems (50.4%), EGFR <60 ml/min (18.9%), heart disease (16.5%) and proteinuria (14.7%). Many had an elevated cardiovascular risk with elevated blood pressure (36%), LDL (71.0%) and smoking (13%), but few were taking antihypertensive drugs (47.1%), statins (28.5%) and aspirin (30.0%) when indicated. Few patients on insulin (8.0%), statins (8.4%) and antihypertensives (39.5%) reached treatment targets according to national guidelines. There were large differences between countries in terms of disease profile and medication use.

Conclusion: DM patients in government clinics in four LMIC with considerable growth of DM have insufficient glycaemic control, frequent macrovascular and other complications, and insufficient preventive measures for cardiovascular disease. These findings underline the need to identify treatment barriers and secure optimal DM care in such settings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/tmi.13137DOI Listing
October 2018

A semi-automatic technique to quantify complex tuberculous lung lesions on F-fluorodeoxyglucose positron emission tomography/computerised tomography images.

EJNMMI Res 2018 Jun 25;8(1):55. Epub 2018 Jun 25.

Division of Nuclear Medicine, Department of Medical Imaging and Clinical Oncology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Background: There is a growing interest in the use of F-FDG PET-CT to monitor tuberculosis (TB) treatment response. However, TB causes complex and widespread pathology, which is challenging to segment and quantify in a reproducible manner. To address this, we developed a technique to standardise uptake (Z-score), segment and quantify tuberculous lung lesions on PET and CT concurrently, in order to track changes over time. We used open source tools and created a MATLAB script. The technique was optimised on a training set of five pulmonary tuberculosis (PTB) cases after standard TB therapy and 15 control patients with lesion-free lungs.

Results: We compared the proposed method to a fixed threshold (SUV > 1) and manual segmentation by two readers and piloted the technique successfully on scans of five control patients and five PTB cases (four cured and one failed treatment case), at diagnosis and after 1 and 6 months of treatment. There was a better correlation between the Z-score-based segmentation and manual segmentation than SUV > 1 and manual segmentation in terms of overall spatial overlap (measured in Dice similarity coefficient) and specificity (1 minus false positive volume fraction). However, SUV > 1 segmentation appeared more sensitive. Both the Z-score and SUV > 1 showed very low variability when measuring change over time. In addition, total glycolytic activity, calculated using segmentation by Z-score and lesion-to-background ratio, correlated well with traditional total glycolytic activity calculations. The technique quantified various PET and CT parameters, including the total glycolytic activity index, metabolic lesion volume, lesion volumes at different CT densities and combined PET and CT parameters. The quantified metrics showed a marked decrease in the cured cases, with changes already apparent at month one, but remained largely unchanged in the failed treatment case.

Conclusions: Our technique is promising to segment and quantify the lung scans of pulmonary tuberculosis patients in a semi-automatic manner, appropriate for measuring treatment response. Further validation is required in larger cohorts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13550-018-0411-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6020088PMC
June 2018

Patients with Concurrent Tuberculosis and Diabetes Have a Pro-Atherogenic Plasma Lipid Profile.

EBioMedicine 2018 Jun 17;32:192-200. Epub 2018 May 17.

Department of Infectious Diseases, Leiden University Medical Centre, Leiden, The Netherlands. Electronic address:

Background: Type 2 diabetes mellitus (DM) is a major risk factor for development of tuberculosis (TB), however the underlying molecular foundations are unclear. Since lipids play a central role in the development of both DM and TB, lipid metabolism may be important for TB-DM pathophysiology.

Methods: A H NMR spectroscopy-based platform was used to determine 225 lipid and other metabolic intermediates in plasma samples of healthy controls (n = 50) and patients with TB (n = 50), DM (n = 50) or TB-DM (n = 27).

Results: TB patients presented with wasting disease, represented by decreased amino acid levels including histidine and alanine. Conversely, DM patients were dyslipidemic as evidenced by high levels of very low-density lipoprotein triglycerides and low high-density lipoprotein cholesterol. TB-DM patients displayed metabolic characteristics of both wasting and dyslipidemia combined with disease interaction-specific increases in phospholipid metabolites (e.g. sphingomyelins) and atherogenic remnant-like lipoprotein particles. Biomarker analysis identified the ratios of phenylalanine/histidine and esterified cholesterol/sphingomyelin as markers for TB classification regardless of DM-status.

Conclusions: TB-DM patients possess a distinctive plasma lipid profile with pro-atherogenic properties. These findings support further research on the benefits of improved blood lipid control in the treatment of TB-DM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ebiom.2018.05.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6020709PMC
June 2018

Predicting tuberculosis treatment outcome using metabolomics.

Biomark Med 2017 Dec 27;11(12):1057-1067. Epub 2017 Nov 27.

School for Physical & Chemical Sciences, Human Metabolomics, North-West University (Potchefstroom Campus), Private Bag x6001, Box 269, Potchefstroom 2531, South Africa.

Aim: Predicting a poor treatment outcome would offer significant benefits for patient care and for new drug development. Materials, methods & results: Urine samples from tuberculosis-positive patients with a successful and unsuccessful treatment outcome were collected at baseline and analyzed. The identified metabolites were used in a forward logistic regression model, which achieved a receiver operating characteristic area under the curve of 0.94 (95% CI: 0.84-1) and cross-validated well in a leave-one-out context, with an area under the curve of 0.89 (95% CI: 0.7-1). Two possible predictors were identified, which are associated with a gut microbiota imbalance.

Discussion & Conclusion: Our findings show the capacity of metabolomics to predict treatment failure at the time of diagnosis, which potentially offers significant benefits for the use in new drug development clinical trials and individualized patient care.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2217/bmm-2017-0133DOI Listing
December 2017

Host blood RNA signatures predict the outcome of tuberculosis treatment.

Tuberculosis (Edinb) 2017 12 12;107:48-58. Epub 2017 Aug 12.

The Center for Infectious Disease Research, Seattle, WA, USA. Electronic address:

Biomarkers for tuberculosis treatment outcome will assist in guiding individualized treatment and evaluation of new therapies. To identify candidate biomarkers, RNA sequencing of whole blood from a well-characterized TB treatment cohort was performed. Application of a validated transcriptional correlate of risk for TB revealed symmetry in host gene expression during progression from latent TB infection to active TB disease and resolution of disease during treatment, including return to control levels after drug therapy. The symmetry was also seen in a TB disease signature, constructed from the TB treatment cohort, that also functioned as a strong correlate of risk. Both signatures identified patients at risk of treatment failure 1-4 weeks after start of therapy. Further mining of the transcriptomes revealed an association between treatment failure and suppressed expression of mitochondrial genes before treatment initiation, leading to development of a novel baseline (pre-treatment) signature of treatment failure. These novel host responses to TB treatment were integrated into a five-gene real-time PCR-based signature that captures the clinically relevant responses to TB treatment and provides a convenient platform for stratifying patients according to their risk of treatment failure. Furthermore, this 5-gene signature is shown to correlate with the pulmonary inflammatory state (as measured by PET-CT) and can complement sputum-based Gene Xpert for patient stratification, providing a rapid and accurate alternative to current methods.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tube.2017.08.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5658513PMC
December 2017

Changes in Host Immune-Endocrine Relationships during Tuberculosis Treatment in Patients with Cured and Failed Treatment Outcomes.

Front Immunol 2017 15;8:690. Epub 2017 Jun 15.

SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Department of Biomedical Sciences, Stellenbosch University, Cape Town, South Africa.

A bidirectional communication between the immune and endocrine systems exists and facilitates optimum responses in the host during infections. This is in part achieved through changes in secretion patterns of hypothalamic hormones induced by inflammatory cytokines. The aim of this study was to elucidate the immune-endocrine alterations during tuberculosis (TB) treatment in patients with cured and failed TB treatment outcomes. Blood samples were collected from 27 cured and 10 failed patients and hormone as well as cytokine concentrations quantified at baseline, week 4, and month 6 of TB treatment. Hormone profiles of the two treatment outcome groups were different from each other prior to as well as during TB treatment. Treatment response effects were observed for cortisol, estradiol, T3, T4 ghrelin, leptin, amylin, adiponectin, and dehydroepiandrosterone (DHEA). Trends suggest that T4, amylin, and DHEA concentrations were different between treatment outcomes, although these did not reach statistical significance. Relationships between endocrine and inflammatory markers and the biological pathways involved differed between cured and failed treatment patients. These results highlight the complex interaction between the endocrine and immune system during active TB disease and throughout treatment and suggest that endocrine markers in conjunction with inflammatory markers may be useful in predicting unfavorable treatment outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2017.00690DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5475380PMC
June 2017

Defining a Research Agenda to Address the Converging Epidemics of Tuberculosis and Diabetes: Part 2: Underlying Biologic Mechanisms.

Chest 2017 07 20;152(1):174-180. Epub 2017 Apr 20.

School of Public Health, University of Texas Health Science Center Houston, Brownsville, TX.

There is growing interest in the re-emerging interaction between type 2 diabetes (DM) and TB, but the underlying biologic mechanisms are poorly understood despite their possible implications in clinical management. Experts in epidemiologic, public health, basic science, and clinical studies recently convened and identified research priorities for elucidating the underlying mechanisms for the co-occurrence of TB and DM. We identified gaps in current knowledge of altered immunity in patients with DM during TB, where most studies suggest an underperforming innate immunity, but exaggerated adaptive immunity to Mycobacterium tuberculosis. Various molecular mechanisms and pathways may underlie these observations in the DM host. These include signaling induced by excess advanced glycation end products and their receptor, higher levels of reactive oxidative species and oxidative stress, epigenetic changes due to chronic hyperglycemia, altered nuclear receptors, and/or differences in cell metabolism (immunometabolism). Studies in humans at different stages of DM (no DM, pre-DM, and DM) or TB (latent or active TB) should be complemented with findings in animal models, which provide the unique opportunity to study early events in the host-pathogen interaction. Such studies could also help identify biomarkers that will complement clinical studies in order to tailor the prevention of TB-DM, or to avoid the adverse TB treatment outcomes that are more likely in these patients. Such studies will also inform new approaches to host-directed therapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chest.2017.02.032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5577357PMC
July 2017

Defining a Research Agenda to Address the Converging Epidemics of Tuberculosis and Diabetes: Part 1: Epidemiology and Clinical Management.

Chest 2017 07 20;152(1):165-173. Epub 2017 Apr 20.

Department of Internal Medicine, Radbourd University Medical Center, Nijmegen, the Netherlands.

There is growing interest in the interaction between type 2 diabetes mellitus (DM) and TB, but many research questions remain unanswered. Epidemiologists, basic scientists, and clinical experts recently convened and identified priorities. This is the first of two reviews on this topic, summarizing priority areas of research regarding epidemiology, clinical management, and public health. First, from an epidemiologic point of view, more study is needed to determine the importance of transient hyperglycemia in patients with TB and on the importance of DM for the global epidemic of multidrug resistant (MDR)-TB. Second, regarding the screening and clinical management of combined TB and DM (TB-DM), clinical trials and large cohort studies should examine the benefits of improved DM care as well as prolonged or intensified TB treatment on the outcome of TB-DM and investigate the cost-effectiveness of screening methods for DM among patients newly diagnosed with TB. Third, from a public health and health systems point of view, the population health impact and cost-effectiveness of different interventions to prevent or treat DM and TB in high-burden populations should be examined, and health-system interventions should be developed for routine TB-DM screening, management of DM after completion of TB treatment, and better access to DM services worldwide. Studies are needed across different ethnicities and settings given the heterogeneity of metabolic perturbations, inflammatory responses, medications, and access to health care. Finally, studies should address interactions between TB, DM, and HIV because of the convergence of epidemics in sub-Saharan Africa and some other parts of the world.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chest.2017.04.155DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5989639PMC
July 2017

High-throughput Identification of DNA-Encoded IgG Ligands that Distinguish Active and Latent Mycobacterium tuberculosis Infections.

ACS Chem Biol 2017 01 13;12(1):234-243. Epub 2016 Dec 13.

Department of Chemistry The Scripps Research Institute 130 Scripps Way Jupiter, FL 33458.

The circulating antibody repertoire encodes a patient's health status and pathogen exposure history, but identifying antibodies with diagnostic potential usually requires knowledge of the antigen(s). We previously circumvented this problem by screening libraries of bead-displayed small molecules against case and control serum samples to discover "epitope surrogates" (ligands of IgGs enriched in the case sample). Here, we describe an improved version of this technology that employs DNA-encoded libraries and high-throughput FACS-based screening to discover epitope surrogates that differentiate noninfectious/latent (LTB) patients from infectious/active TB (ATB) patients, which is imperative for proper treatment selection and antibiotic stewardship. Normal control/LTB (10 patients each, NCL) and ATB (10 patients) serum pools were screened against a library (5 × 10 beads, 448 000 unique compounds) using fluorescent antihuman IgG to label hit compound beads for FACS. Deep sequencing decoded all hit structures and each hit's occurrence frequencies. ATB hits were pruned of NCL hits and prioritized for resynthesis based on occurrence and homology. Several structurally homologous families were identified and 16/21 resynthesized representative hits validated as selective ligands of ATB serum IgGs (p < 0.005). The native secreted TB protein Ag85B (though not the E. coli recombinant form) competed with one of the validated ligands for binding to antibodies, suggesting that it mimics a native Ag85B epitope. The use of DNA-encoded libraries and FACS-based screening in epitope surrogate discovery reveals thousands of potential hit structures. Distilling this list down to several consensus chemical structures yielded a diagnostic panel for ATB composed of thermally stable and economically produced small molecule ligands in place of protein antigens.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acschembio.6b00855DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5250564PMC
January 2017

Successful TB treatment induces B-cells expressing FASL and IL5RA mRNA.

Oncotarget 2017 Jan;8(2):2037-2043

SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Activated B-cells increase T-cell behaviour during autoimmune disease and other infections by means of cytokine production and antigen-presentation. Functional studies in experimental autoimmune encephalomyelitis (EAE) indicate that B-cell deficiencies, and a lack of IL10 and IL35 leads to a poor prognosis. We hypothesised that B-cells play a role during tuberculosis. We evaluated B-cell mRNA expression using real-time PCR from healthy community controls, individuals with other lung diseases and newly diagnosed untreated pulmonary TB patients at three different time points (diagnosis, month 2 and 6 of treatment).We show that FASLG, IL5RA, CD38 and IL4 expression was lower in B-cells from TB cases compared to healthy controls. The changes in expression levels of CD38 may be due to a reduced activation of B-cells from TB cases at diagnosis. By month 2 of treatment, there was a significant increase in the expression of APRIL and IL5RA in TB cases. Furthermore, after 6 months of treatment, APRIL, FASLG, IL5RA and CD19 were upregulated in B-cells from TB cases. The increase in the expression of APRIL and CD19 suggests that there may be restored activation of B-cells following anti-TB treatment. The upregulation of FASLG and IL5RA indicates that B-cells expressing regulatory genes may play an important role in the protective immunity against M.tb infection. Our results show that increased activation of B-cells is present following successful TB treatment, and that the expression of FASLG and IL5RA could potentially be utilised as a signature to monitor treatment response.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18632/oncotarget.12184DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5356777PMC
January 2017

Persisting positron emission tomography lesion activity and Mycobacterium tuberculosis mRNA after tuberculosis cure.

Nat Med 2016 10 5;22(10):1094-1100. Epub 2016 Sep 5.

National Medical Center, Seoul, South Korea.

The absence of a gold standard to determine when antibiotics induce a sterilizing cure has confounded the development of new approaches to treat pulmonary tuberculosis (PTB). We detected positron emission tomography and computerized tomography (PET-CT) imaging response patterns consistent with active disease, along with the presence of Mycobacterium tuberculosis (MTB) mRNA in sputum and bronchoalveolar lavage samples, in a substantial proportion of adult, HIV-negative patients with PTB after a standard 6-month treatment plus 1 year follow-up, including patients with a durable cure and others who later developed recurrent disease. The presence of MTB mRNA in the context of nonresolving and intensifying lesions on PET-CT images might indicate ongoing transcription, suggesting that even apparently curative treatment for PTB may not eradicate all of the MTB bacteria in most patients. This suggests an important complementary role for the immune response in maintaining a disease-free state. Sterilizing drugs or host-directed therapies, and better treatment response markers, are probably needed for the successful development of improved and shortened PTB-treatment strategies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5053881PMC
http://dx.doi.org/10.1038/nm.4177DOI Listing
October 2016