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Wayengera M, Kateete DP, Asiimwe B, Joloba ML. Mycobacterium tuberculosis thymidylate kinase antigen assays for designating incipient, high-risk latent M.tb infection. BMC Infect Dis 2018; 18:133. [PMID: 29548281 PMCID: PMC5857104 DOI: 10.1186/s12879-018-3007-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 02/21/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Precise designation of high risk forms of latent Mycobacterium tuberculosis-M.tb infections (LTBI) is impossible. Delineation of high-risk LTBI can, however, allow for chemoprophylaxis and curtail majority cases of active tuberculosis (ATB). There is epidemiological evidence to support the view that LTBI in context of HIV-1 co-infection is high-risk for progression to ATB relative to LTBI among HIV-ve persons. We recently showed that assays of M.tb thymidylate kinase (TMKmt) antigen and host specific IgG can differentiate ATB from LTBI and or no TB (NTB, or healthy controls). In this study, we aimed to expose the differential levels of TMKmt Ag among HIV+ve co-infected LTBI relative to HIV-ve LTBI as a strategy to advance these assays for designating incipient LTBI. METHODS TMKmt host specific IgM and IgG detection Enzyme Immuno-Assays (EIA) were conducted on 40 TB exposed house-hold contacts (22 LTBI vs. 18 no TB (NTB) by QunatiFERON-TB GOLD®); and TMKmt Ag detection EIA done on 82 LTBI (46 HIV+ve vs 36 HIV-ve) and 9 NTB (American donors). Purified recombinant TMKmt protein was used as positive control for the Ag assays. RESULTS IgM levels were found to be equally low across QuantiFERON-TB GOLD® prequalified NTB and TB exposed house-hold contacts. Higher TMKmt host specific IgG trends were found among TB house-hold contacts relative to NTB controls. TMKmt Ag levels among HIV+ve LTBI were 0.2676 ± 0.0197 (95% CI: 0.2279 to 0.3073) relative to 0.1069 ± 0.01628 (95% CI: 0.07385 to 0.14) for HIV-ve LTBI (supporting incipient nature of LTBI in context of HIV-1 co-infection). NTB had TMKmt Ag levels of 0.1013 ± 0.02505 (5% CI: 0.0421 to 0.1606) (intimating that some were indeed LTBI). CONCLUSIONS TMKmt Ag levels represent a novel surrogate biomarker for high-risk LTBI, while host-specific IgG can be used to designate NTB from LTBI.
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Affiliation(s)
- Misaki Wayengera
- Department of Pathology, Unit of Genetics & Genomics, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda. .,Department of Immunology &Molecular Biology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda.
| | - David P Kateete
- Department of Immunology &Molecular Biology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda.,Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Benon Asiimwe
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Moses L Joloba
- Department of Immunology &Molecular Biology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda.,Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
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Wayengera M, Mwebaza I, Welishe J, Bayiyana A, Kateete DP, Wampande E, Kirimunda S, Kigozi E, Katabazi F, Musubika C, Kyobe S, Babirye P, Asiimwe B, Joloba ML. Immuno-diagnosis of Mycobacterium tuberculosis in sputum, and reduction of timelines for its positive cultures to within 3 h by pathogen-specific thymidylate kinase expression assays. BMC Res Notes 2017; 10:368. [PMID: 28789704 PMCID: PMC5549350 DOI: 10.1186/s13104-017-2649-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 07/21/2017] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Laboratory diagnosis of Tuberculosis (TB) is traditionally based on microscopy and or culture. Microscopy is however, only sensitive to a specified degree of bacillary load not present in HIV co-infected persons. Traditional cultures of Mycobacterium tuberculosis (M. tb), on the other hand, take weeks to read-thereby delaying the critical decision whether or not, to treat. Although nucleic acids amplification tests (NAATS) applied directly on sputum or cultures can increase the sensitivity for TB diagnosis among those with HIV co-infection as well as reduce time-lines for positive culture detection, they do not replace the need for smear microscopy and culture. We have previously proposed the M. tb DNA-synthetic enzyme thymidylate kinase (aka TMKmt) as an organism-specific growth and proliferation biomarker to reduce time-lines for detection of positive TB cultures. In this study, we explored the secretory levels of TMKmt in M. tb cultures and sputum, towards improving the overall laboratory diagnosis of TB. METHODS AND RESULTS Modelling of TMKmt secretion in vitro was done by cloning, expressing and SDS-PAGE/MALDI-TOF detection of purified recombinant TMKmt in E. coli. TMKmt expression profiling in M. tb was done by qRT-PCR assay of related messenger ribonucleic acids (mRNA) and TMKmt antigen detection by Enzyme linked Immuno-absorbent Assay (EIA) among cultures of a pathogenic wild-type Ugandan strain (genotype 1) alongside the H37Rv laboratory strain. Owing to the high-load of pathogen in-culture, direct EIA on limiting dilutions of sputum were done to examine for assay sensitivity. A rise in TMKmt antigen levels was observed at 3 h post-innoculation among in vitro cultures of E. coli. The 1st of several cyclic spikes in TMKmt mRNA and antigen levels were detected at 2.5 h among in vitro cultures of the pathogenic wild-type Ugandan isolate alongside the laboratory M. tb strain. TMKmt antigen was detected up to between 1 × 10-4-1 × 10-5 (containing 10 and 1 CFUs/ml) dilutions of a microscopically designated 1+ (est. Acid Fast Bacillary load of 1 × 105) patient sample. CONCLUSIONS Detection of TMKmt expressed mRNA and Ag offers us opportune for instant diagnosis of M. tb in sputum, and reduction of timelines for positive pathogen detection in cultures to within 3 h.
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Affiliation(s)
- Misaki Wayengera
- Unit of Genetics & Genomics, Dept. of Pathology, School of Biomedical Science, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Ivan Mwebaza
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Johnson Welishe
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Alice Bayiyana
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - David P. Kateete
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Eddie Wampande
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Samuel Kirimunda
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Edgar Kigozi
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Fred Katabazi
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Carol Musubika
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Samuel Kyobe
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Peace Babirye
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Benon Asiimwe
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
| | - Moses L. Joloba
- Dept of Immunology/Molecular Biology (Mycobacteriology Laboratory), School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
- Dept. of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, P o Box 7072, Kampala, Uganda
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Wayengera M, Mwebaza I, Welishe J, Nakimuli C, Kateete DP, Wampande E, Kirimunda S, Bayigga L, Musubika C, Babirye P, Asiimwe B, Joloba ML. Sero-diagnosis of Active Mycobacterium tuberculosis Disease among HIV Co-infected Persons using Thymidylate Kinase based Antigen and Antibody Capture Enzyme Immuno-Assays. MYCOBACTERIAL DISEASES : TUBERCULOSIS & LEPROSY 2017; 7:241. [PMID: 28856068 PMCID: PMC5573238 DOI: 10.4172/2161-1068.1000241] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Clinical and laboratory diagnosis of Active Tuberculosis (ATB) and latent Mycobacterium Tuberculosis (M. tuberculosis) infections (LTBI) among people living with HIV/AIDS (PLWHA) presents formidable challenges. In the past, WHO issued an advisory against the use of existing TB sero-diagnostics. Emerging evidence, however, points to a precision of TB sero-diagnostics based on secretory rather than structural M. tuberculosis antigens. We hypothesized that secretory levels of M. tuberculosis thymidylate kinase (TMKmt) can Designate ATBI from LTBI and no TB (NTB). Here, we report in-house validation studies of levels of TMKmt antigen (Ag) and host specific TMKmt antibody (Ab) amongst HIV +ve and HIV -ve participants. METHODS AND RESULTS Direct TMKmt Ag and host specific IgG Ab detection EIAs were conducted on broadly consented, stored serum (N=281[Ag] vs. 214 [Ab] respective) samples stratified as either HIV +ve or HIV-ve ATB relative to LTBI and No TB. On one hand, UG-peptide 1 and its PAb-based EIAs accurately diagnosed ATB relative to LTBI and NTB among HIV +ve subjects {irrespectively: (a) Ag detection ATB=OD>0.490; 95% CI: 0.7446 to 0.8715 vs. LTBI=OD<0.490; 95% CI 0.4325 to 0.4829 vs. NTB=OD<0.26; 95% CI 0.1675 to 0.2567 and (b) TMKmt specific IgG detection ATB=OD>1.00; 95% CI 1.170 to 1.528 [HIV +ve] and 2.044 to 2.978 [HIV -ve] respectively vs. LTBI=OD<1.00; 95% CI 0.2690 to 0.6396 vs. NTB=OD<; 95% CI 0.1527 to 0.8751}. HIV -ve ATB presented with Ag levels greater than NTB and less than LTBI (i.e. ATB -ve=<0.490 ODs>0.26), but displayed better ant-TMKmt IgG responses (OD>2.00; 95% CI 2.044 to 2.978) relative to HIV +ve ATB (OD<1.600; 95% CI 1.170 to 1.528); suggesting a better control of M. tuberculosis-septicemia. On the other hand, UG-peptide 2 and its PAb-based EIAs did not demonstrate ATB diagnostic potential regardless of HIV sero-status, except towards designating NTB. CONCLUSIONS TMKmt Ab and Ag detecting EIAs based on UG-peptide 1 and its derivative PAb can accurately demarcate ATB from LTBI and NTB among HIV +ve subjects.
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Affiliation(s)
- Misaki Wayengera
- Department of Pathology, Unit of Genetics and Genomics, School of Biomedical Science, Makerere University College of Health Sciences, Kampala, Uganda
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | - Ivan Mwebaza
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
| | - Johnson Welishe
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
| | - Cynthia Nakimuli
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
| | - David P Kateete
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | - Eddie Wampande
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | - Samuel Kirimunda
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | - Lois Bayigga
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | - Carol Musubika
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | - Peace Babirye
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
| | - Benon Asiimwe
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | - Moses L Joloba
- Department of Immunology/Molecular Biology/Mycobacteriology, School of Biomedical Sciences, Makerere University College of Health Sciences, Uganda
- Department of Medical Microbiology, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
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