Publications by authors named "Novel N Chegou"

58 Publications

Serum and cerebrospinal fluid host proteins indicate stroke in children with tuberculous meningitis.

PLoS One 2021 30;16(4):e0250944. Epub 2021 Apr 30.

Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Introduction: Stroke is a common complication in children with tuberculous meningitis (TBM). Host proteins may give us insight into the mechanisms of stroke in TBM and serve as biomarkers for detection of stroke, however, they have not been widely explored. In this study, we compared the concentrations of cerebrospinal fluid (CSF) and serum proteins between children who had TBM-related stroke and children with TBM without stroke.

Methods: We collected CSF and serum from 47 children consecutively admitted to the Tygerberg Academic Hospital in Cape Town, South Africa between November 2016, and November 2017, on suspicion of having TBM. A multiplex platform was used to measure the concentrations of 69 host proteins in CSF and serum from all study participants.

Results: After classification of study participants, 23 (48.9%) out of the 47 study participants were diagnosed with TBM, of which 14 (60.9%) demonstrated radiological arterial ischemic infarction. The levels of lipocalin-2, sRAGE, IP-10/ CXCL10, sVCAM-1, MMP-1, and PDGF-AA in CSF samples and the levels of D-dimer, ADAMTS13, SAA, ferritin, MCP-1/ CCL2, GDF-15 and IL-13 in serum samples were statistically different between children who had TBM-related stroke and children with TBM without stroke. After correcting for multiple testing, only the levels of sVCAM-1, MMP-1, sRAGE, and IP-10/ CXCL10 in CSF were statistically different between the two groups. CSF and serum protein biosignatures indicated stroke in children diagnosed with TBM with up to 100% sensitivity and 88.9% specificity.

Conclusion: Serum and CSF proteins may serve as biomarkers for identifying individuals with stroke amongst children diagnosed with TBM at admission and may guide us to understand the biology of stroke in TBM. This was a pilot study, and thus further investigations in larger studies are needed.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0250944PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8087017PMC
April 2021

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

A Plasma 5-Marker Host Biosignature Identifies Tuberculosis in High and Low Endemic Countries.

Front Immunol 2021 24;12:608846. Epub 2021 Feb 24.

Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.

Several host inflammatory markers have been proposed as biomarkers for diagnosis and treatment response in Tuberculosis (TB), but few studies compare their utility in different demographic, ethnic, and TB endemic settings. Fifty-four host biomarkers were evaluated in plasma samples obtained from presumed TB cases recruited at the Oslo University Hospital in Norway, and a health center in Cape Town, South Africa. Based on clinical and laboratory assessments, participants were classified as having TB or other respiratory diseases (ORD). The concentrations of biomarkers were analyzed using the Luminex multiplex platform. Out of 185 study participants from both study sites, 107 (58%) had TB, and 78 (42%) ORD. Multiple host markers showed diagnostic potential in both the Norwegian and South African cohorts, with I-309 as the most accurate single marker irrespective of geographical setting. Although study site-specific biosignatures had high accuracy for TB, a site-independent 5-marker biosignature (G-CSF, C3b/iC3b, procalcitonin, IP-10, PDGF-BB) was identified diagnosing TB with a sensitivity of 72.7% (95% CI, 49.8-82.3) and specificity of 90.5% (95% CI, 69.6-98.8) irrespective of geographical site. A 5-marker host plasma biosignature has diagnostic potential for TB disease irrespective of TB setting and should be further explored in larger cohorts.
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http://dx.doi.org/10.3389/fimmu.2021.608846DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7958880PMC
February 2021

Inflammatory Determinants of Differential Tuberculosis Risk in Pre-Adolescent Children and Young Adults.

Front Immunol 2021 25;12:639965. Epub 2021 Feb 25.

South African Tuberculosis Vaccine Initiative (SATVI), Department of Pathology, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, University of Cape Town, Cape Town, South Africa.

The risk of progression from ( infection to active tuberculosis (TB) disease varies markedly with age. TB disease is significantly less likely in pre-adolescent children above 4 years of age than in very young children or post-pubescent adolescents and young adults. We hypothesized that pro-inflammatory responses to in pre-adolescent children are either less pronounced or more regulated, than in young adults. Inflammatory and antimicrobial mediators, measured by microfluidic RT-qPCR and protein bead arrays, or by analyzing published microarray data from TB patients and controls, were compared in pre-adolescent children and adults. Multivariate analysis revealed that -uninfected 8-year-old children had lower levels of myeloid-associated pro-inflammatory mediators than uninfected 18-year-old young adults. Relative to uninfected children, those with -infection had higher levels of similar myeloid inflammatory responses. These inflammatory mediators were also expressed after stimulation of whole blood from uninfected children with live . Our findings suggest that myeloid inflammation is intrinsically lower in pre-pubescent children than in young adults. The lower or more regulated pro-inflammatory responses may play a role in the lower risk of TB disease in this age group.
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http://dx.doi.org/10.3389/fimmu.2021.639965DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7947716PMC
February 2021

Evaluation of Host Serum Protein Biomarkers of Tuberculosis in sub-Saharan Africa.

Front Immunol 2021 25;12:639174. Epub 2021 Feb 25.

Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom.

Accurate and affordable point-of-care diagnostics for tuberculosis (TB) are needed. Host serum protein signatures have been derived for use in primary care settings, however validation of these in secondary care settings is lacking. We evaluated serum protein biomarkers discovered in primary care cohorts from Africa reapplied to patients from secondary care. In this nested case-control study, concentrations of 22 proteins were quantified in sera from 292 patients from Malawi and South Africa who presented predominantly to secondary care. Recruitment was based upon intention of local clinicians to test for TB. The case definition for TB was culture positivity for ; and for other diseases (OD) a confirmed alternative diagnosis. Equal numbers of TB and OD patients were selected. Within each group, there were equal numbers with and without HIV and from each site. Patients were split into training and test sets for biosignature discovery. A nine-protein signature to distinguish TB from OD was discovered comprising fibrinogen, alpha-2-macroglobulin, CRP, MMP-9, transthyretin, complement factor H, IFN-gamma, IP-10, and TNF-alpha. This signature had an area under the receiver operating characteristic curve in the training set of 90% (95% CI 86-95%), and, after adjusting the cut-off for increased sensitivity, a sensitivity and specificity in the test set of 92% (95% CI 80-98%) and 71% (95% CI 56-84%), respectively. The best single biomarker was complement factor H [area under the receiver operating characteristic curve 70% (95% CI 64-76%)]. Biosignatures consisting of host serum proteins may function as point-of-care screening tests for TB in African hospitals. Complement factor H is identified as a new biomarker for such signatures.
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http://dx.doi.org/10.3389/fimmu.2021.639174DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7947659PMC
February 2021

Validation and Optimization of Host Immunological Bio-Signatures for a Point-of-Care Test for TB Disease.

Front Immunol 2021 26;12:607827. Epub 2021 Feb 26.

Department of Science and Innovation - National Research Foundation (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.

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.
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http://dx.doi.org/10.3389/fimmu.2021.607827DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7952865PMC
February 2021

Higher SARS-CoV-2 seroprevalence in workers with lower socioeconomic status in Cape Town, South Africa.

PLoS One 2021 25;16(2):e0247852. Epub 2021 Feb 25.

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

Background: Inequality is rife throughout South Africa. The first wave of COVID-19 may have affected people in lower socioeconomic groups worse than the affluent. The SARS-CoV-2 seroprevalence and the specificity of anti-SARS-CoV-2 antibody tests in South Africa is not known.

Methods: We tested 405 volunteers representing all socioeconomic strata from the workforce of a popular shopping and tourist complex in central Cape Town with the Abbott SARS-CoV-2 IgG assay. We assessed the association between antibody positivity and COVID-19 symptom status, medical history, and sociodemographic variables. We tested 137 serum samples from healthy controls collected in Cape Town prior to the COVID-19 pandemic, to confirm the specificity of the assay in the local population.

Results: Of the 405 volunteers tested one month after the first peak of the epidemic in Cape Town, 96(23.7%) were SARS-CoV-2 IgG positive. Of those who tested positive, 46(47.9%) reported no symptoms of COVID-19 in the previous 6 months. Seropositivity was significantly associated with living in informal housing, residing in a subdistrict with low income-per household, and having a low-earning occupation. The specificity of the assay was 98.54%(95%CI 94.82%-99.82%) in the pre-COVID controls.

Conclusions: There is a high background seroprevalence in Cape Town, particularly in people of lower socioeconomic status. Almost half of cases are asymptomatic, and therefore undiagnosed by local testing strategies. These results cannot be explained by low assay specificity.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0247852PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7906413PMC
March 2021

Serum cytokine levels associated with myocardial injury in systemic lupus erythematosus.

Rheumatology (Oxford) 2021 Apr;60(4):2010-2021

Division of Cardiology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Academic Hospital, Cape Town, South Africa.

Objectives: To identify cytokines, markers of endothelial activation [soluble vascular cell adhesion molecule-1 (sVCAM-1)] and myocyte strain [soluble ST2 (sST2)] associated with myocardial injury (MInj) in SLE, classified by cardiac magnetic resonance (CMR) criteria.

Methods: CMR was performed on patients with SLE, identifying stages of MInj (inflammation and necrosis or fibrosis). Data captured included: clinical assessment, laboratory and serological analyses, cytokine (IL-1β, IL-1Ra, IL-2, IL-6, IL-10, IL-17, IL-18, TNF-alpha), sVCAM-1 and sST2 levels. Cytokines were compared with regard to SLE features and evidence of CMR MInj. Predictors of CMR MInj were determined through regression analyses.

Results: Forty-one patients with high disease activity (SLEDAI-2K: 13; IQR: 3-17) were included. SLE features included: LN (n = 12), neurolupus (n = 6) and clinical lupus myocarditis (LM) (n = 6). Nineteen patients had CMR evidence of MInj. Patients with a SLEDAI-2K ≥ 12 had higher sVCAM-1 (P = 0.010) and sST2 (P = 0.032) levels. Neurolupus was associated with higher IL-1Ra (P = 0.038) and LN with lower IL-1Ra (P = 0.025) and sVCAM-1 (P = 0.036) levels. Higher IL-1Ra (P = 0.012), IL-17 (P = 0.045), IL-18 (P = 0.003), and sVCAM-1 (P = 0.062) levels were observed in patients with CMR MInj compared with those without. On multivariable logistic regression, IL-1Ra predicted CMR inflammation and fibrosis/necrosis (P < 0.005) while anti-Ro/SSA [odds ratio (OR): 1.197; P = 0.035] and the SLE damage index (OR: 4.064; P = 0.011) predicted fibrosis/necrosis.

Conclusion: This is a novel description of associations between cytokines and SLE MInj. IL-18 and IL-1Ra were significantly higher in patients with MInj. IL-1Ra independently predicted different stages of CMR MInj. Exploration of the role of these cytokines in the pathogenesis of SLE MInj may promote targeted therapies for LM.
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http://dx.doi.org/10.1093/rheumatology/keaa540DOI Listing
April 2021

Tuberculous Meningitis: Pathogenesis, Immune Responses, Diagnostic Challenges, and the Potential of Biomarker-Based Approaches.

J Clin Microbiol 2021 Feb 18;59(3). Epub 2021 Feb 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

Tuberculous meningitis (TBM) is the most devastating form of tuberculosis (TB), causing high mortality or disability. Clinical management of the disease is challenging due to limitations of the existing diagnostic approaches. Our knowledge on the immunology and pathogenesis of the disease is currently limited. More research is urgently needed to enhance our understanding of the immunopathogenesis of the disease and guide us toward the identification of targets that may be useful for vaccines or host-directed therapeutics. In this review, we summarize the current knowledge about the immunology and pathogenesis of TBM and summarize the literature on existing and new, especially biomarker-based, approaches that may be useful in the management of TBM. We identify research gaps and provide directions for research which may lead to the development of new tools for the control of the disease in the near future.
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http://dx.doi.org/10.1128/JCM.01771-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8106718PMC
February 2021

Host urine immunological biomarkers as potential candidates for the diagnosis of tuberculosis.

Int J Infect Dis 2020 Oct 12;99:473-481. Epub 2020 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, P.O. Box 241, Cape Town 8000, South Africa. Electronic address:

Objective: To investigate the potential of host urinary biomarkers as diagnostic candidates for tuberculosis (TB).

Methods: 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.

Results: 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%).

Conclusions: 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.
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http://dx.doi.org/10.1016/j.ijid.2020.08.019DOI Listing
October 2020

Evaluation of Potential Antigen-specific Host Biomarkers in QuantiFERON Supernatants as Candidates for the Diagnosis of Ocular Tuberculosis.

Ocul Immunol Inflamm 2020 Jul 7:1-9. Epub 2020 Jul 7.

DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, Stellenbosch University, Cape Town, South Africa.

Purpose: To evaluate potential host biomarkers detectable in QuantiFERON supernatants as diagnostic candidates for ocular tuberculosis (OTB).

Methods: We investigated 47 host markers in QuantiFERON supernatants from 92 individuals with uveitis using the Luminex platform. We evaluated the potential of individual and combined biomarkers to distinguish between patients with possible, probable, and no OTB.

Results: Differences were observed in median concentrations of several biomarkers including IL-13, IFN-γ, IFN-α2, and IL-1β, in individuals with OTB versus no OTB regardless of HIV status. Individuals with probable and possible OTB only differed regarding GM-CSF. We identified a four-marker biosignature (CD40 L, IL-33, IFN-γ, and SAP) which diagnosed OTB with an area under the ROC curve of 0.80, sensitivity = 56.3% and specificity = 90.0%.

Conclusion: This represents the first attempt at screening QuantiFERON supernatants for biomarkers to diagnose OTB. We identified candidate biosignatures which may aid in diagnosing OTB in both HIV positive and negative patients.
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http://dx.doi.org/10.1080/09273948.2020.1763404DOI Listing
July 2020

RISK6, a 6-gene transcriptomic signature of TB disease risk, diagnosis and treatment response.

Sci Rep 2020 05 25;10(1):8629. Epub 2020 May 25.

South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa.

Improved tuberculosis diagnostics and tools for monitoring treatment response are urgently needed. We developed a robust and simple, PCR-based host-blood transcriptomic signature, RISK6, for multiple applications: identifying individuals at risk of incident disease, as a screening test for subclinical or clinical tuberculosis, and for monitoring tuberculosis treatment. RISK6 utility was validated by blind prediction using quantitative real-time (qRT) PCR in seven independent cohorts. Prognostic performance significantly exceeded that of previous signatures discovered in the same cohort. Performance for diagnosing subclinical and clinical disease in HIV-uninfected and HIV-infected persons, assessed by area under the receiver-operating characteristic curve, exceeded 85%. As a screening test for tuberculosis, the sensitivity at 90% specificity met or approached the benchmarks set out in World Health Organization target product profiles for non-sputum-based tests. RISK6 scores correlated with lung immunopathology activity, measured by positron emission tomography, and tracked treatment response, demonstrating utility as treatment response biomarker, while predicting treatment failure prior to treatment initiation. Performance of the test in capillary blood samples collected by finger-prick was noninferior to venous blood collected in PAXgene tubes. These results support incorporation of RISK6 into rapid, capillary blood-based point-of-care PCR devices for prospective assessment in field studies.
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http://dx.doi.org/10.1038/s41598-020-65043-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7248089PMC
May 2020

Distinct host-immune response toward species related intracellular mycobacterial killing: A transcriptomic study.

Virulence 2020 12;11(1):170-182

NRF-DST 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.

The comparison of the host immune response when challenged with pathogenic and nonpathogenic species of mycobacteria can provide answers to the unresolved question of how pathogens subvert or inhibit an effective response. We infected human monocyte derived macrophages (hMDMs) with different species of mycobacteria, in increasing order of pathogenicity, i.e. BCG, and R179 that had been cultured in the absence of detergents. RNA was isolated post-infection and transcriptomic analysis using amplicons (Ampliseq) revealed 274 differentially expressed genes (DEGs) across three species, out of which we selected 19 DEGs for further validation. We used qRT-PCR to confirm the differential expression of 19 DEGs. We studied biological network through Ingenuity Pathway Analysis® (IPA) which revealed up-regulated pathways of the interferon and interleukin family related to the killing of . Apart from interferon and interleukin family, we found one up-regulated ( and two down-regulated ( and ) genes as unique potential targets found by Ampliseq and qRT-PCR which may be involved in the intracellular mycobacterial killing. The roles of these genes have not previously been described in tuberculosis. Multiplex ELISA of culture supernatants showed increased host immune response toward as compared to BCG and R179. These results enhance our understanding of host immune response against infection.
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http://dx.doi.org/10.1080/21505594.2020.1726561DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7051142PMC
December 2020

Effects of on Inflammation, Apoptosis, and Organ Toxicity in STZ-Induced Diabetic Cardiomyopathy.

Biomedicines 2020 Feb 8;8(2). Epub 2020 Feb 8.

Phytomedicine & Phytochemistry Group, Oxidative Stress Research Centre, Department of Biomedical Sciences, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Bellville 7535, South Africa.

Persistent hyperglycemia is known to cause enhanced generation of reactive oxygen species in diabetes. Several inflammatory cytokines are induced by oxidative stress, and their release also leads to increased oxidative stress; this makes oxidative stress one of the important factors in the development of chronic inflammation and other immune responses. These have been implicated in the development of diabetic complications such as nephropathy and cardiomyopathy. has been shown to possess antioxidant and anti-inflammatory potentials. The present study investigated the immunomodulatory potential and the antiapoptotic ability of to ameliorate heart toxicity and injury in type II diabetes. Two weeks of fructose (10%) administration followed by single intraperitoneal injection of streptozotocin (40 mg/kg) were used to induce type II diabetes in male Wistar rats. Leaf extract (aqueous) of (200 and 400 mg/kg) was administered orally for six weeks. Blood glucose concentrations and body weights before and after interventions were determined. Interleukin (IL)-1β, IL-6, IL-10, IL-18, monocyte chemoattractant protein 1 (MCP-1), and tumor necrosis factor alpha (TNFα) were measured in the heart homogenates. Catalase (CAT), superoxide dismutase (SOD), total protein, oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), thiobarbituric acid reactive substances (TBARS), and heart-type fatty acid-binding protein (H-FABP) levels were determined. Expressions of transcription factors (Nrf 2 and NFkB/p65) and apoptotic markers were also investigated in the heart. administration reduced pro-inflammatory cytokines, increased anti-inflammatory markers, and enhanced antioxidant defense in the heart of diabetic treated animals. is a new, promising therapeutic agent that can be explored for the treatment of pathological conditions associated with immune responses and will be a useful tool in the management of associated diabetic complications.
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http://dx.doi.org/10.3390/biomedicines8020029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7168158PMC
February 2020

The gut microbiome in tuberculosis susceptibility and treatment response: guilty or not guilty?

Cell Mol Life Sci 2020 Apr 15;77(8):1497-1509. Epub 2019 Nov 15.

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, P.O. Box 241, Cape Town, 8000, South Africa.

Although tuberculosis (TB) is a curable disease, it remains the foremost cause of death from a single pathogen. Globally, approximately 1.6 million people died of TB in 2017. Many predisposing factors related to host immunity, genetics and the environment have been linked to TB. However, recent evidence suggests a relationship between dysbiosis in the gut microbiome and TB disease development. The underlying mechanism(s) whereby dysbiosis in the gut microbiota may impact the different stages in TB disease progression, are, however, not fully explained. In the wake of recently emerging literature, the gut microbiome could represent a potential modifiable host factor to improve TB immunity and treatment response. Herein, we summarize early data detailing (1) possible association between gut microbiome dysbiosis and TB (2) the potential for the use of microbiota biosignatures to discriminate active TB disease from healthy individuals (3) the adverse effect of protracted anti-TB antibiotics treatment on gut microbiota balance, and possible link to increased susceptibility to Mycobacterium tuberculosis re-infection or TB recrudescence following successful cure. We also discuss immune pathways whereby the gut microbiome could impact TB disease and serve as target for clinical manipulation.
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http://dx.doi.org/10.1007/s00018-019-03370-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7162824PMC
April 2020

Identification of Potential Biomarkers in Peripheral Blood Supernatants of South African Patients with Syphilitic and Herpetic Uveitis.

Ocul Immunol Inflamm 2021 Feb 7;29(2):299-307. Epub 2019 Nov 7.

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.

: To identify potential diagnostic biomarkers for herpetic and syphilitic uveitis.: Blood samples were collected from 92 uveitis patients. Concentrations of 47 biomarkers were evaluated in unstimulated Quantiferon supernatants using the Luminex platform.: Results showed 11 patients (12%) had herpetic uveitis, 11 (12%) syphilis, 40 (43.5%) other infectious causes, 16 (17.4%) established noninfectious causes and 14 (15.2%) were idiopathic. Biomarker analysis revealed three proteins (Apo-A1, Apo-CIII, CRP) that differed between syphilis and other causes. A three-marker biosignature (CCL4/MIP-1β, Apo-CIII and CRP) separated syphilis from other groups with AUC = 0.83 (95% CI: 0.68-0.98). Apo-CIII and CRP differed between herpetic cases and other groups ( < .05). A three-analyte biosignature (Apo-A1, SAP and CRP) separated the herpetic group from other groups with AUC = 0.79 (95% CI: 0.65-0.93).: We have identified candidate biomarkers with potential to differentiate between herpetic, syphilitic and other causes of uveitis. These results warrant further investigation in larger future studies.
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http://dx.doi.org/10.1080/09273948.2019.1674341DOI Listing
February 2021

Potential of Host Serum Protein Biomarkers in the Diagnosis of Tuberculous Meningitis in Children.

Front Pediatr 2019 25;7:376. Epub 2019 Sep 25.

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, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Tuberculous meningitis (TBM) is the most severe form of tuberculosis and results in high morbidity and mortality in children. Diagnostic delay contributes to the poor outcome. There is an urgent need for new tools for the rapid diagnosis of TBM, especially in children. We collected serum samples from children in whom TBM was suspected at a tertiary hospital in Cape Town, South Africa. Children were subsequently classified as having TBM or no TBM using a published uniform research case-definition. Using a multiplex cytokine array platform, we investigated the concentrations of serum biomarkers comprising biomarkers that were previously found to be of value in the diagnosis of adult pulmonary TB (CRP, SAA, CFH, IFN-γ, IP-10, Apo-AI, and transthyretin) plus other potentially useful host biomarkers as diagnostic candidates for TBM. Out of 47 children included in the study, 23 (48.9%) had a final diagnosis of TBM and six were HIV infected. A modified version of the adult 7-marker biosignature in which transthyretin was replaced by NCAM1, diagnosed TBM in children with AUC of 0.80 (95% CI, 0.67-0.92), sensitivity of 73.9% (95% CI, 51.6-89.8%) and specificity of 66.7% (95% CI, 44.7-84.4%), with the other six proteins in the signature (CRP, IFN-γ, IP-10, CFH, Apo-A1, and SAA) only achieving and AUC of 0.75 (95% CI, 0.61-0.90) when used in combination. A new childhood TBM specific 3-marker biosignature (adipsin, Aβ42, and IL-10) showed potential in the diagnosis of TBM, with AUC of 0.84 (95% CI, 0.73-0.96), sensitivity of 82.6% (95 CI, 61.2-95.0%) and specificity of 75.0% (95% CI, 53.3-90.2%) after leave-one-out cross validation. A previously described adult 7-marker serum protein biosignature showed potential in the diagnosis of TBM in children. However, a smaller childhood TBM-specific 3-marker signature demonstrated improved performance characteristics. Our data indicates that blood-based biomarkers may be useful in the diagnosis of childhood TBM and requires further validation in larger cohort studies.
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http://dx.doi.org/10.3389/fped.2019.00376DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6773834PMC
September 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.
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http://dx.doi.org/10.1016/j.tube.2019.101859DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6839616PMC
September 2019

Prospective evaluation of host biomarkers other than interferon gamma in QuantiFERON Plus supernatants as candidates for the diagnosis of tuberculosis in symptomatic individuals.

J Infect 2019 09 15;79(3):228-235. Epub 2019 Jul 15.

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, Po Box 241, Cape Town 8000, South Africa. Electronic address:

Background: There is an urgent need for new tools for the diagnosis of TB. We evaluated the usefulness recently described host biomarkers in supernatants from the newest generation of the QuantiFERON test (QuantiFERON Plus) as tools for the diagnosis of active TB.

Methods: We recruited individuals presenting at primary health care clinics in Cape Town, South Africa with symptoms requiring investigation for TB disease, prior to the establishment of a clinical diagnosis. Participants were later classified as TB or other respiratory diseases (ORD) based on the results of clinical and laboratory tests. Using a multiplex platform, we evaluated the concentrations of 37 host biomarkers in QuantiFERON Plus supernatants from study participants as tools for the diagnosis of TB.

Results: Out of 120 study participants, 35(29.2%) were diagnosed with active TB, 69(57.5%) with ORD whereas 16(13.3%) were excluded. 14(11.6%) of the study participants were HIV infected. Although individual host markers showed potential as diagnostic candidates, the main finding of the study was the identification of a six-marker biosignature in unstimulated supernatants (Apo-ACIII, CXCL1, CXCL9, CCL8, CCL-1, CD56) which diagnosed TB with sensitivity and specificity of 73.9%(95% CI; 51.6-87.8) and 87.6%(95% CI; 77.2-94.5), respectively, after leave-one-out cross validation. Combinations between TB-antigen specific biomarkers also showed potential (sensitivity of 77.3% and specificity of 69.2%, respectively), with multiple biomarkers being significantly different between TB patients, Quantiferon Plus Positive and Quantiferon Plus negative individuals with ORD, regardless of HIV status.

Conclusions: Biomarkers detected in QuantiFERON Plus supernatants may contribute to adjunctive diagnosis of TB.
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http://dx.doi.org/10.1016/j.jinf.2019.07.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6692655PMC
September 2019

Application of Cerebrospinal Fluid Host Protein Biosignatures in the Diagnosis of Tuberculous Meningitis in Children from a High Burden Setting.

Mediators Inflamm 2019 16;2019:7582948. Epub 2019 Apr 16.

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, Po Box 241, Cape Town 8000, South Africa.

Background: The diagnosis of tuberculous meningitis (TBM) especially in children is challenging. New tests are urgently needed for the diagnosis of the disease, especially in resource-limited settings.

Methods: We collected cerebrospinal fluid (CSF) samples from children presenting with symptoms requiring investigation for meningitis at a tertiary hospital in Cape Town, South Africa. Children were later classified as TBM or no TBM using published case definitions. Using a multiplex platform, we investigated the concentrations of biomarkers comprising a previously established 3-marker biosignature (VEGF, IL-13, and LL-37) and other potentially useful host biomarkers as diagnostic candidates for TBM.

Findings: Out of 47 children, age, 3 months to 13 years, 23 were diagnosed with TBM and six (16%) were HIV-infected. We validated the previously identified CSF biosignature (sensitivity of 95.7% (95% CI, 79.0-99.2%) and specificity of 37.5% (95% CI, 21.2-57.3%)). However, substitution of IL-13 and LL-37 with IFN- and MPO, respectively, resulted in improved accuracy (area under the ROC curve (AUC) = 0.97, 95% CI, 0.92-1.00, up to 91.3% (21/23) sensitivity and up to 100% (24/24) specificity). An alternative four-marker biosignature (sICAM-1, MPO, CXCL8, and IFN-) also showed potential, with an AUC of 0.97.

Conclusion: We validated a previously identified CSF biosignature and showed that refinement of this biosignature by incorporation of other biomarkers diagnosed TBM with high accuracy. Incorporation of these biomarkers into a point-of-care or bedside diagnostic test platform may result in the improved management of TBM in children.
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http://dx.doi.org/10.1155/2019/7582948DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6501148PMC
December 2019

Long-Term Impact of Neonatal Intake of Oleanolic Acid on the Expression of AMP-Activated Protein Kinase, Adiponectin and Inflammatory Cytokines in Rats Fed with a High Fructose Diet.

Nutrients 2019 Jan 22;11(2). Epub 2019 Jan 22.

Department of Biochemistry, Faculty of Natural and Agricultural Science, North West University, Mafikeng Campus, Private Bag X2046, Mmabatho 2735, South Africa.

AMP-activated protein kinase (AMPK) is known to regulate both glucose and lipid metabolism, which play vital roles in the development of metabolic syndrome. One way of regulating AMPK is through hormonal activation using adiponectin. Patients diagnosed with type-2 diabetes (T2D) and obesity exhibit low adiponectin concentration levels in their blood. Moreover, studies have also shown that inflammatory processes play a significant role in the etiology of these metabolic diseases. In this study, the long-term effects of neonatal intake of oleanolic acid (OA) on the gene, genes associated with glucose transport and lipid metabolism, adiponectin levels, and inflammatory biomarkers in rats fed with a high fructose diet were investigated. Seven day old pups were randomly divided into five groups and treated as follows; 0.5% dimethylsulphoxide / in distilled water vehicle control (CON), oleanolic acid (OA, 60 mg/kg), high fructose diet (HF, 20% /), high fructose diet combined with oleanolic acid (HF+OA), and high fructose diet combined with metformin (HF+MET, 500 mg/kg). The treatments were administered once daily until day 14. The rats were then weaned at day 21 and fed standard rat chow and had access to plain drinking water until day 112. The quantitative polymerase chain reaction (qPCR) was used to analyze the gene expressions of , , , , , , and in the skeletal muscles. Bio-Plex Pro magnetic bead-based assay was used to measure plasma levels of inflammatory markers (TNF-α, IL-6, VEGF, and MCP-1) while ELISA kits were used to measure adiponectin concentration in blood plasma. The results obtained in this study showed that neonatal supplementation with OA significantly increased gene expression approximately ~4-fold in OA fed rats compared to those that were fed with HF alone. In addition, glut-4 gene expression was also significantly higher in the OA treatment group compared to all the other experimental groups except the CON group whereas gene was more expressed when OA was administered alone. Together, these results indicated that OA can play a role in glucose and lipid metabolism gene regulation. Furthermore, the results showed that the OA group had ~1.5-fold increase in adiponectin concentration when comparedto the HF group. Moreover, HF increased levels of inflammatory cytokines, which was attenuated by neonatal administration of OA. Plasma concentration and gene expression in the skeletal muscle for TNF-α and IL-6 were significantly increased in rats that were treated with HF alone when compared to all the other groups. On the contrary, the high levels of TNF-α and IL-6 were reduced when OA was administered. These findings suggest that intake of oleanolic acid during the neonatal stage of development could be a potential strategic intervention for the long-term prevention of metabolic diseases such as T2D and obesity.
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http://dx.doi.org/10.3390/nu11020226DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412886PMC
January 2019

Modulation of Inflammatory Cytokines and Islet Morphology as Therapeutic Mechanisms of in Streptozotocin-Induced Diabetic Rats.

Toxicol Res 2018 Oct 15;34(4):325-332. Epub 2018 Oct 15.

Department of Biomedical Sciences, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Bellville, Cape Town, South Africa.

The mechanism of the previously reported antidiabetic effect of is unknown. This study investigated the role of aqueous leaf extract in the modulation of inflammatory cytokines and islet morphology in streptozotocin-induced diabetic rats. Forty male Wistar rats, between 8 and 10 weeks old, were randomly divided into four groups (n = 10) and administered the following treatments: Healthy control (H-c) and Diabetic control (D-c) animals received normal saline 0.5 mL/100 g body weight daily, while Healthy Treatment (H-Ba) and Diabetic Treatment (D-Ba) rats received the plant extract 200 mg/kg body weight daily. All treatments were administered by oral gavage. Diabetes was induced in D-c and D-Ba rats by a single intraperitoneal injection of streptozotocin (55 mg/kg body). The body weight and fasting blood sugar (FBS) levels were recorded every week for 4 weeks, after which the rats were euthanized and samples collected for further analysis. After the experiment, FBS level was significantly reduced ( < 0.0001) in rats in the D-Ba group, but increased ( < 0.001) in rats in the D-c group. The absolute (H-c and H-Ba vs D-c, < 0.05) and relative (D-Ba vs H-c, < 0.05; D-Ba vs H-Ba, < 0.005) weights of the pancreases were significantly higher after the experiment. The rats in the D-c group had significantly higher levels of serum interleukin-1β ( < 0.001 vs H-c; < 0.05 vs H-Ba and D-Ba) and monocyte chemotactic protein-1 ( < 0.0001), but lower levels of interleukin-10 ( < 0.05) in comparison with the other groups. Histopathological examination revealed severe interstitial congestion, reduced islet area ( < 0.0001), and increased islet cell density in the D-c group compared with those in the D-Ba group. From these findings, it was concluded that the aqueous extract of stimulates the recovery of beta-islet morphology in streptozotocin-induced diabetic rats by modulating the peripheral production of inflammatory cytokines.
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http://dx.doi.org/10.5487/TR.2018.34.4.325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6195884PMC
October 2018

Tuberculosis: advances and challenges in development of new diagnostics and biomarkers.

Lancet Infect Dis 2018 07 23;18(7):e199-e210. Epub 2018 Mar 23.

Centre for Clinical Microbiology, Division of Infection and Immunity, University College London (UCL), London, UK; National Institute of Health and Research Biomedical Research Centre, UCL Hospitals National Health Service Foundation Trust, London, UK; University of Zambia-University College London Medical School Research and Training Programme, University Teaching Hospital, Lusaka, Zambia. Electronic address:

Tuberculosis remains the leading cause of death from an infectious disease worldwide. Early and accurate diagnosis and detection of drug-sensitive and drug-resistant tuberculosis is essential for achieving global tuberculosis control. Despite the introduction of the Xpert MTB/RIF assay as the first-line rapid tuberculosis diagnostic test, the gap between global estimates of incidence and new case notifications is 4·1 million people. More accurate, rapid, and cost-effective screening tests are needed to improve case detection. Diagnosis of extrapulmonary tuberculosis and tuberculosis in children, people living with HIV, and pregnant women remains particularly problematic. The diagnostic molecular technology landscape has continued to expand, including the development of tests for resistance to several antituberculosis drugs. Biomarkers are urgently needed to indicate progression from latent infection to clinical disease, to predict risk of reactivation after cure, and to provide accurate endpoints for drug and vaccine trials. Sophisticated bioinformatic computational tools and systems biology approaches are being applied to the discovery and validation of biomarkers, with substantial progress taking place. New data have been generated from the study of T-cell responses and T-cell function, serological studies, flow cytometric-based assays, and protein and gene expression studies. Alternative diagnostic strategies under investigation as potential screening and triaging tools include non-sputum-based detection with breath-based tests and automated digital radiography. We review developments and key achievements in the search for new tuberculosis diagnostics and biomarkers. We highlight gaps and challenges in evaluation and rollout of new diagnostics and biomarkers, and prioritise areas needing further investment, including impact assessment and cost-benefit studies.
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http://dx.doi.org/10.1016/S1473-3099(18)30111-7DOI Listing
July 2018

Africa-wide evaluation of host biomarkers in QuantiFERON supernatants for the diagnosis of pulmonary tuberculosis.

Sci Rep 2018 02 8;8(1):2675. Epub 2018 Feb 8.

Vaccines and Immunity, Medical Research Council Unit, Fajara, The Gambia.

We investigated host-derived biomarkers that were previously identified in QuantiFERON supernatants, in a large pan-African study. We recruited individuals presenting with symptoms of pulmonary TB at seven peripheral healthcare facilities in six African countries, prior to assessment for TB disease. We then evaluated the concentrations of 12 biomarkers in stored QuantiFERON supernatants using the Luminex platform. Based on laboratory, clinical and radiological findings and a pre-established algorithm, participants were classified as TB disease or other respiratory diseases(ORD). Of the 514 individuals included in the study, 179(34.8%) had TB disease, 274(51.5%) had ORD and 61(11.5%) had an uncertain diagnosis. A biosignature comprising unstimulated IFN-γ, MIP-1β, TGF-α and antigen-specific levels of TGF-α and VEGF, identified on a training sample set (n = 311), validated by diagnosing TB disease in the test set (n = 134) with an AUC of 0.81(95% CI, 0.76-0.86), corresponding to a sensitivity of 64.2%(95% CI, 49.7-76.5%) and specificity of 82.7%(95% CI, 72.4-89.9%). Host biomarkers detected in QuantiFERON supernatants can contribute to the diagnosis of active TB disease amongst people presenting with symptoms requiring investigation for TB disease, regardless of HIV status or ethnicity in Africa.
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http://dx.doi.org/10.1038/s41598-018-20855-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5805775PMC
February 2018

Suitability of saliva for Tuberculosis diagnosis: comparing with serum.

BMC Infect Dis 2017 08 31;17(1):600. Epub 2017 Aug 31.

Uganda - Case Western Research Collaboration, Mulago-Kampala, Uganda.

Background: In the search for fast, simple and better ways for diagnosis of tuberculosis (TB), there is need to discover and evaluate new biomarkers that are found in samples other than sputum to determine their effectiveness. This study examined the utility of saliva vis-a-vis serum by evaluating levels of biomarkers found in saliva and serum from TB suspects.

Methods: Study enrolled tuberculosis suspects. Sputum MGIT was used as the gold standard for active TB. Quantiferon gold-In tube assay was done to identify exposure to Mycobacterium tuberculosis (M.tb). Multiplex assay was run for 10 markers using a 10 plex customized kit from Bio-Rad Laboratories.

Results: There was a significant difference between saliva and serum marker levels. Saliva had significantly higher levels of GM-CSF and VEGF. Serum had higher levels of MIP-1a, b, TNF-a, G-CSF and IFN-g. Serum levels of IL-6, VEGF and TNF-a were significantly different between participants with active TB disease and those with other respiratory diseases.

Conclusion: Salivary TB biomarkers are worth the search to evaluate their ability to differentiate between TB disease states for generation of a non invasive point of care test for TB diagnosis.
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http://dx.doi.org/10.1186/s12879-017-2687-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5580300PMC
August 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.
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http://dx.doi.org/10.3389/fimmu.2017.00690DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5475380PMC
June 2017

Hepatoprotective, Antihyperlipidemic, and Anti-inflammatory Activity of in Diabetic-induced Damage in Male Wistar Rats.

Pharmacognosy Res 2017 Apr-Jun;9(2):182-187

Department of Biomedical Sciences, Nutrition and Chronic Diseases Research Unit, Oxidative Stress Research Centre, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Bellville 7535, South Africa.

Background: The number of individuals with diabetes is increasing daily, and diabetes is presently estimated to affect about 422 million adults worldwide. Conventional drugs used to treat diabetes are not without severe side effects, accessibility, and affordability. This study elucidates the potential effects of (MO) leaves extract to manage and treat diabetes induced in male Wistar rats.

Materials And Methods: Adult male Wistar rats were randomly divided into four groups ( = 12/group): NC - nondiabetic rats (positive control), MO - nondiabetic-treated rats, DM - diabetic rats (negative control), DM + MO - diabetic-treated rats. Hepatic enzymes and biochemical parameters as well as antioxidant capacity and inflammatory cytokine levels were assessed. Levels of low-density lipoprotein, high-density lipoprotein, and total cholesterol were evaluated.

Results: Oral administration of methanolic extract of MO (250 mg/kg) to diabetic rats for 42 days showed a significant reduction in hepatic enzyme markers and normalized lipid profile parameters in the serum compared to normal control group. Treatment also increased the level of antioxidant capacity and alleviated inflammatory biomarkers of the liver. Histology sections of the liver tissue showed protective effect of MO in treated rats.

Conclusions: MO showed hepatoprotective, anti-inflammatory, and lipid-lowering effects against streptozotocin-induced hepatotoxicity. Histological section demonstrated specific alterations in the liver of the diabetic and nondiabetic male Wistar rats while MO treatment revealed improvement in liver alterations.

IL 1: Interleukin 1, IL 6: Interleukin 16, MCP-1: Monocyte chemotactic protein, TNF-α: Tumor Necrotic factor alpha, ROS: Reactive oxygen species, MO: , STZ: Streptozotocin, SRC: Standard rat chow, ALP: Alkaline phosphatase, AST: Aspartate aminotransferase, ALT: Alanine aminotransferase, ORAC: Oxygen radical absorbance capacity, LDL: Low density lipoprotein, HDL: High density lipoprotein, CHOL: Total cholesterol.
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http://dx.doi.org/10.4103/0974-8490.204651DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5424560PMC
May 2017

Centella asiatica enhances hepatic antioxidant status and regulates hepatic inflammatory cytokines in type 2 diabetic rats.

Pharm Biol 2017 Dec;55(1):1671-1678

a Discipline of Biochemistry , School of Life Sciences, University of KwaZulu-Natal , Durban , South Africa.

Context: Neutralizing the over-activation of oxidative stress and inflammation remains an important goal in the management of type 2 diabetes mellitus (T2DM). Centella asiatica (L.) Urban (Apiaceae) (CA) has been used in traditional folklore in Africa and Asia to treat various ailments including diabetes.

Objective: We investigated the hepatic antioxidant and anti-inflammatory potential of methanol extract of CA leaves in T2DM.

Materials And Methods: T2DM was induced in male Sprague-Dawley rats with 10% fructose in drinking water for 14 days followed by a single intraperitoneal injection of streptozotocin (40 mg/kg b.wt). Hepatic oxidant/antioxidant status was assessed by measuring the concentrations of malondialdehyde (MDA), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), Trolox equivalent antioxidant capacity (TEAC), reduced glutathione (GSH) and activities of glutathione S-transferase (GST) and glutathione peroxidase (GPX). The concentrations of cytokines IL-1β, IL-4, IL-6, IL-10, MCP-1 and TNF-α in the liver were determined.

Results: Diabetes increased MDA formed (47%) and reduced FRAP (20%), TEAC (15%), GSH levels (32%), significantly; decreased GST and GPX activities in the liver and elevated levels of cytokines studied. Treatment of diabetic rats with 500 mg/kg b.wt CA for 14 days decreased MDA (44%); elevated FRAP (15%) and GSH (131%) levels and increased the activities of GST and GPX by 16%. Hepatic concentrations of IL-1β, MCP-1 and TNF-α in DCA group were reduced to 68%, 75% and 63% of DC values, respectively.

Conclusions: The antioxidant and anti-inflammatory properties of CA may protect tissues such as the liver from diabetes-induced oxidative damage.
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http://dx.doi.org/10.1080/13880209.2017.1318293DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6130484PMC
December 2017

Detection of a combination of serum IgG and IgA antibodies against selected mycobacterial targets provides promising diagnostic signatures for active TB.

Oncotarget 2017 Jun;8(23):37525-37537

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

Immunoglobulin G (IgG) based tests for the diagnosis of active tuberculosis (TB) disease often show a lack of specificity in TB endemic regions, which is mainly due to a high background prevalence of LTBI. Here, we investigated the combined performance of the responses of different Ig classes to selected mycobacterial antigens in primary healthcare clinic attendees with signs and symptoms suggestive of TB. The sensitivity and specificity of IgA, IgG and/or IgM to LAM and 7 mycobacterial protein antigens (ESAT-6, Tpx, PstS1, AlaDH, MPT64, 16kDa and 19kDa) and 2 antigen combinations (TUB, TB-LTBI) in the plasma of 63 individuals who underwent diagnostic work-up for TB after presenting with symptoms and signs compatible with possible active TB were evaluated. Active TB was excluded in 42 individuals of whom 21 has LTBI whereas active TB was confirmed in 21 patients of whom 19 had a follow-up blood draw at the end of 6-month anti-TB treatment. The leading single serodiagnostic markers to differentiate between the presence or absence of active TB were anti-16 kDa IgA, anti-MPT64 IgA with sensitivity and specificity of 90%/90% and 95%/90%, respectively. The combined use of 3 or 4 antibodies further improved this performance to accuracies above 95%. After successful completion of anti-TB treatment at month 6, the levels of 16 kDa IgA and 16 kDa IgM dropped significantly whereas LAM IgG and TB-LTBI IgG increased. These results show the potential of extending investigation of anti-tuberculous IgG responses to include IgM and IgA responses against selected protein and non-protein antigens in differentiating active TB from other respiratory diseases in TB endemic settings.
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http://dx.doi.org/10.18632/oncotarget.16401DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5514927PMC
June 2017

Identification of novel host biomarkers in plasma as candidates for the immunodiagnosis of tuberculosis disease and monitoring of tuberculosis treatment response.

Oncotarget 2016 Sep;7(36):57581-57592

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

There is an urgent need for new tools for the rapid diagnosis of tuberculosis disease. We evaluated the potentials of 74 host markers as biomarkers for the immunological diagnosis of tuberculosis and monitoring of treatment response. Fifty-five individuals that presented with signs and symptoms requiring investigation for tuberculosis disease were prospectively recruited prior to clinical diagnosis, at a health centre in Cape Town, South Africa. Patients were later classified as having tuberculosis disease or other respiratory diseases (ORD) using a combination of clinical, radiological and laboratory findings. Out of 74 host markers that were evaluated in plasma samples from study participants using a multiplex platform, 18 showed potential as tuberculosis diagnostic candidates with the most promising being NCAM, CRP, SAP, IP-10, ferritin, TPA, I-309, and MIG, which diagnosed tuberculosis disease individually, with area under the ROC curve ≥0.80. Six-marker biosignatures containing NCAM diagnosed tuberculosis disease with a sensitivity of 100% (95%CI, 86.3-100%) and specificity of 89.3% (95%CI, 67.6-97.3%) irrespective of HIV status, and 100% accuracy in the absence of HIV infection. Furthermore, the concentrations of 11 of these proteins changed with treatment, thereby indicating that they may be useful in monitoring of the response to tuberculosis treatment. Our findings have potential to be translated into a point-of-care screening test for tuberculosis, after future validation studies.
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http://dx.doi.org/10.18632/oncotarget.11420DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5295374PMC
September 2016