Papers by Hygon Mutavhatsindi
PLOS global public health, Apr 11, 2024
We report the safety and immunogenicity of fractional and full dose Ad26.COV2.S and BNT162b2 in a... more We report the safety and immunogenicity of fractional and full dose Ad26.COV2.S and BNT162b2 in an open label phase 2 trial of participants previously vaccinated with a single dose of Ad26.COV2.S, with 91.4% showing evidence of previous SARS-CoV-2 infection. A total of 286 adults (with or without HIV) were enrolled >4 months after an Ad26.COV2.S prime and randomized 1:1:1:1 to receive either a full or half-dose booster of Ad26.COV2.S or BNT162b2 vaccine. B cell responses (binding, neutralization and antibody dependent PLOS GLOBAL PUBLIC HEALTH
Frontiers in Immunology, Feb 26, 2021
Organization (WHO) target product profile requirements for a triage test in both HIVnegative and ... more Organization (WHO) target product profile requirements for a triage test in both HIVnegative and HIV-positive individuals. This signature could be incorporated into a point-ofcare 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.
Research Square (Research Square), Oct 28, 2020
Background: The diagnosis of TB remains one of the major challenges in the control of the disease... more Background: The diagnosis of TB remains one of the major challenges in the control of the disease, due to limitations in the currently available diagnostic tests. There is an urgent need for new, accurate, rapid, and affordable diagnostic tests. The aim of the present study was to use mass spectrometry to identify new candidate TB diagnostic protein biomarkers in saliva obtained from individuals with TB, and patients with other respiratory diseases (ORD). Methods: Saliva samples were collected from 22 individuals who self-presented with symptoms requiring investigation for TB as part of a larger TB biomarker project. Eleven of the participants were nally diagnosed with TB using routine clinical, radiological and laboratory tests and 11 with ORD. Salivary proteins were concentrated and puri ed, followed by tryptic digestion. Peptides were analyzed using a QExactive Orbitrap MS coupled to a Dionex liquid chromatography system. Raw les were processed using MaxQuant software against the database of human proteins. Identi ed proteins were subjected to gene ontology and ingenuity pathway analysis for functional enrichment analysis. Results: We identi ed 1176 protein groups across all samples, of which 46 (3.91%) were contaminants, 12 (1.02%) were reverse hits and 170 (14.46%) were single-peptide protein groups. After removal of the contaminants, reverse hits and protein groups represented by single peptides, 26 of the remaining 948 proteins signi cantly discriminated individuals with TB from those with ORD after Benjamini Hochberg correction, with ve of these proteins diagnosing TB with AUC ³ 0.80. A 5-protein biosignature comprising of P01011, Q8NCW5, P28072, A0A2Q2TTZ9 and Q99574 diagnosed TB with an AUC of 1.00 (95% CI, 1.00-1.00), sensitivity of 100% (95% CI, 76.2-100%) and speci city of 90.9% (95% CI, 58.7-99.8%) after leave-one-out cross validation. Conclusions: We identi ed novel salivary protein biomarkers and biosignatures with strong potential as TB diagnostic candidates. Our results are preliminary and require validation in larger studies.
bioRxiv (Cold Spring Harbor Laboratory), Oct 24, 2022
Objectives. To better understand the pathogenesis of pericardial tuberculosis (PCTB), we sought t... more Objectives. To better understand the pathogenesis of pericardial tuberculosis (PCTB), we sought to characterize the systemic inflammatory profile in HIV-1-infected participants with latent TB infection (LTBI), pulmonary TB (PTB) and PCTB. Methods. Using Luminex, we measured 39 analytes in pericardial fluid (PCF) and paired plasma from 18 PCTB participants, and plasma from 16 LTBI and 20 PTB. Follow-up plasma samples were also obtained from PTB and PCTB participants. HLA-DR expression on Mtb-specific CD4 T cells was measured in baseline samples using flow cytometry. Results. Assessment of the overall systemic inflammatory profile by principal component analysis showed that the inflammatory profile of active TB participants was distinct from the LTBI group, while PTB patients could not be distinguished from those with PCTB. In the LTBI group, 12 analytes showed a positive association with plasma HIV-1 viral load, and most of these associations were lost in the diseased groups. When comparing the inflammatory profile between PCF and paired blood, we found that the concentrations of most analytes (24/39) were elevated at site of disease. However, the inflammatory profile in PCF partially mirrored inflammatory events in the blood. After TB treatment completion, the overall plasma inflammatory profile reverted to those observed in the LTBI group. Lastly, HLA-DR expression showed the best performance for TB diagnosis compared to previously described biosignatures built from soluble markers. Conclusion. Our results describe the inflammatory profile associated with PTB and PCTB and emphasize the potential role of HLA-DR as a promising biomarker for TB diagnosis.
medRxiv (Cold Spring Harbor Laboratory), Jun 6, 2021
doi: medRxiv preprint NOTE: This preprint reports new research that has not been certified by pee... more doi: medRxiv preprint NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice.
Open Forum Infectious Diseases
Objectives To better understand the pathogenesis of pericardial tuberculosis (PCTB), we sought to... more Objectives To better understand the pathogenesis of pericardial tuberculosis (PCTB), we sought to characterize the systemic inflammatory profile in people with human immunodeficiency virus (HIV-1) with latent TB infection (LTBI), pulmonary TB (PTB) and PCTB. Methods Using Luminex, we measured the concentration of 39 analytes in pericardial fluid (PCF) and paired plasma from 18 PCTB participants, and plasma from 16 LTBI and 20 PTB. Follow-up plasma samples were also obtained from PTB and PCTB participants. HLA-DR expression on Mtb-specific CD4 T cells was measured in baseline samples using flow cytometry. Results Assessment of the overall systemic inflammatory profile by principal component analysis showed that the inflammatory profile of active TB participants was distinct from the LTBI group, while PTB patients could not be distinguished from those with PCTB. When comparing the inflammatory profile between PCF and paired blood, we found that the concentrations of most analytes (24/...
ObjectivesTo better understand the pathogenesis of pericardial tuberculosis (PCTB), we sought to ... more ObjectivesTo better understand the pathogenesis of pericardial tuberculosis (PCTB), we sought to characterize the systemic inflammatory profile in HIV-1-infected participants with latent TB infection (LTBI), pulmonary TB (PTB) and PCTB.MethodsUsing Luminex, we measured 39 analytes in pericardial fluid (PCF) and paired plasma from 18 PCTB participants, and plasma from 16 LTBI and 20 PTB. Follow-up plasma samples were also obtained from PTB and PCTB participants. HLA-DR expression on Mtb-specific CD4 T cells was measured in baseline samples using flow cytometry.ResultsAssessment of the overall systemic inflammatory profile by principal component analysis showed that the inflammatory profile of active TB participants was distinct from the LTBI group, while PTB patients could not be distinguished from those with PCTB. In the LTBI group, 12 analytes showed a positive association with plasma HIV-1 viral load, and most of these associations were lost in the diseased groups. When comparing ...
Malaria is caused by protozoa of the genus Plasmodium. Malaria accounts for approximately more th... more Malaria is caused by protozoa of the genus Plasmodium. Malaria accounts for approximately more than half a million deaths yearly. Of the five species of Plasmodium, P. falciparum accounts for the most deadly form of the disease. P. falciparum survives under various physiological conditions during its life cycle. The parasite employs its molecular chaperones machinery particularly heat shock proteins (Hsps) to protect its protein constituents during physiological stress. Hsps are conserved molecules that constitute a major part of the cell's molecular chaperone system. P. falciparum Hsps play an important cyto-protective role guaranteeing that the malarial parasite survives under the severe conditions that prevail in the host environment. PFF1010c is a type IV P. falciparum heat shock protein 40. PFF1010c is predicted to be expressed only at the gametocyte stage of the malarial parasite's life cycle. The aim of the current study was to investigate the expression PFF1010c by parasites and the gametocyte stage as well as characterize the structure-function features of the protein. PFF1010c was successfully expressed in E. coli cells. Despite successful expression of the protein, its purification proved problematic. The attempt to purify PFF1010c was carried out under both native and denaturing conditions. Far Western blot analysis to investigate direct interaction between PFF1010c and PfHsp70-1 was conducted and no interaction was observed. Malarial parasites were harvested at different stages and total protein was isolated. The expression of PFF1010c was confirmed to occur at the gametocyte stage of the parasite's development using Western blot analysis. This study confirmed that PFF1010c is only expressed at the gametocyte stage of the malarial parasite. Furthermore, PFF1010c was not expressed at the asexual stage. Possible interactors of PFF1010c were predicted by STRING, a bioinformatics based tool. The expression of PfHsp90, PfHop and PfHsp70-1 at the gametocyte stage was investigated and confirmed by Western blot analyses. iii Declaration I, the undersigned, declare that this thesis submitted to the University of Venda for the degree of Master of Science in Biochemistry at the Department of Biochemistry in the School of Mathematical and Natural Sciences, is my own unaided work, with exception to citations. This work has not been submitted to any other university in partial or entirely for the award of any degree.
Science Translational Medicine, 2022
SARS-CoV-2 variants that escape neutralization and potentially affect vaccine efficacy have emerg... more SARS-CoV-2 variants that escape neutralization and potentially affect vaccine efficacy have emerged. T cell responses play a role in protection from reinfection and severe disease, but the potential for spike mutations to affect T cell immunity is incompletely understood. We assessed neutralizing antibody and T cell responses in 44 South African COVID-19 patients either infected with the Beta variant (dominant from November 2020 to May 2021) or infected before its emergence (first wave, Wuhan strain) to provide an overall measure of immune evasion. We show that robust spike-specific CD4 and CD8 T cell responses were detectable in Beta-infected patients, similar to first-wave patients. Using peptides spanning the Beta-mutated regions, we identified CD4 T cell responses targeting the wild-type peptides in 12 of 22 first-wave patients, all of whom failed to recognize corresponding Beta-mutated peptides. However, responses to mutated regions formed only a small proportion (15.7%) of the...
Biomedical Sciences: Molecular Biology and Human Genetic
PLOS ONE, 2021
Introduction Stroke is a common complication in children with tuberculous meningitis (TBM). Host ... more 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, ...
Background: The diagnosis of TB remains one of the major challenges in the control of the disease... more Background: The diagnosis of TB remains one of the major challenges in the control of the disease, due to limitations in the currently available diagnostic tests. There is an urgent need for new, accurate, rapid, and affordable diagnostic tests. The aim of the present study was to use mass spectrometry to identify new candidate TB diagnostic protein biomarkers in saliva obtained from individuals with TB, and patients with other respiratory diseases (ORD).Methods: Saliva samples were collected from 22 individuals who self-presented with symptoms requiring investigation for TB as part of a larger TB biomarker project. Eleven of the participants were finally diagnosed with TB using routine clinical, radiological and laboratory tests and 11 with ORD. Salivary proteins were concentrated and purified, followed by tryptic digestion. Peptides were analyzed using a QExactive Orbitrap MS coupled to a Dionex liquid chromatography system. Raw files were processed using MaxQuant software against...
Tuberculosis, 2021
BACKGROUND There is an urgent need for new, accurate, rapid, and affordable tuberculosis (TB) dia... more BACKGROUND There is an urgent need for new, accurate, rapid, and affordable tuberculosis (TB) diagnostic tests. The aim of the present study was to use mass spectrometry to identify new preliminary candidate TB diagnostic protein biomarkers in saliva obtained from individuals with TB, and patients with other respiratory diseases (ORD). METHODS Saliva samples were collected from 22 individuals who self-presented with symptoms suggestive of TB as part of a larger TB biomarker project. Purified salivary proteins were subjected to tryptic digestion peptides were analyzed using a QExactive Orbitrap Mass Spectrometer. Data are available via ProteomeXchange with identifier PXD027294. Identified proteins were subjected to gene ontology and ingenuity pathway analysis for functional enrichment analysis. RESULTS 26 of the 652 identified proteins significantly discriminated individuals with TB from those with ORD after Benjamini Hochberg correction (5% FDR), with five of these proteins diagnosing TB with an AUC ≥ 0.80. A 5-protein biosignature comprising of P01011, Q8NCW5, P28072, A0A2Q2TTZ9, and Q99574 diagnosed TB with an AUC of 1.00 (95% CI, 1.00-1.00), sensitivity of 100% (95% CI, 76.2-100%) and specificity of 90.9% (95% CI, 58.7-99.8%) after leave-one-out cross validation. CONCLUSIONS We identified novel candidate salivary protein biomarkers and biosignatures with strong potential as TB diagnostic candidates. Our results are preliminary and require validation in larger studies.
Frontiers in Immunology, 2021
The development of a non-sputum-based, point-of-care diagnostic test for tuberculosis (TB) is a p... more 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-mar...
Scientific Reports, 2020
Improved tuberculosis diagnostics and tools for monitoring treatment response are urgently needed... more 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 correlate...
Frontiers in Pediatrics, 2019
Background: Tuberculous meningitis (TBM) is the most severe form of tuberculosis and results in h... more Background: 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. Methods: 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. Findings: 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. Conclusion: 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.
Journal of Infection, 2019
BMJ Global Health, 2019
BackgroundInexpensive rapid screening tests that can be used at the point-of-care (POC) are vital... more BackgroundInexpensive rapid screening tests that can be used at the point-of-care (POC) are vital to combat tuberculosis. Particularly, less invasive non-sputum-based biomarker tests for all TB forms can help controlling transmission. Availability of such tests would significantly accelerate and streamline diagnostic approaches, improve cost-efficiency and decrease unnecessary costly GeneXpert referrals.MethodsMulti-biomarker test (MBT) devices measuring levels of selections of up to six serum proteins simultaneously on a single lateral flow (LF) strip were produced. The strip contains individual capture lines for a biomarker selection allowing discrimination of TB-patients from other respiratory diseases (ORD). Only biomarkers successfully evaluated with singleplex strips (single biomarker tests) were applied to the MBT device. Quantitative signals are recorded with a low-cost handheld reader compatible with the applied luminescent up-converting particle (UCP) label. Biomarker sele...
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Papers by Hygon Mutavhatsindi