Factors affecting diagnostic and prognostic performance of a transcriptomic signature of risk of tuberculosis in HIV-uninfected South African adults

dc.contributor.advisorHatherill, Mark
dc.contributor.advisorScriba, Thomas J
dc.contributor.authorMulenga, Humphrey
dc.date.accessioned2023-04-04T10:08:12Z
dc.date.available2023-04-04T10:08:12Z
dc.date.issued2022
dc.date.updated2023-04-04T08:47:16Z
dc.description.abstractBackground Host blood transcriptomic signatures, such as RISK11, have potential as tests for diagnosing and predicting tuberculosis. This thesis aimed to review the literature, evaluate host and non-host factors associated with variability of the RISK11 signature and impact on discriminatory performance and evaluate RISK11 performance in combination with tests of Mycobacterium tuberculosis sensitization. Methods A systematic review of discriminatory performance of transcriptomic signatures for tuberculosis was conducted. RISK11, QuantiFERON-TB Gold-Plus and host factors were analysed in a prospective cohort, in which a cross-sectional study of upper respiratory organisms was nested. Effects on RISK11 were quantified using multivariable generalised regression. Discriminatory performance of RISK11, and RISK11/QuantiFERON combinations, were quantified by area under the curve and/or sensitivity and specificity. Results In the literature, one signature (90% sensitivity; 74% specificity) met the minimal criteria for a triage test; one signature (86% sensitivity; 84% specificity) met the minimal criteria for a predictive test. In the prospective cohort, RISK11 scores were higher among individuals with prevalent tuberculosis (+18.90%), night sweats (+14.65%) and incident tuberculosis (+7.29%). Cough was associated with 72.55% higher RISK11 score in prevalent tuberculosis cases. Stratification by cough improved diagnostic performance from area under curve of 0.74 overall, to 0.97 in cough-positive participants. Adjustment for host factors affecting controls did not change RISK11 discriminatory performance. In the cross-sectional study, RISK11 scores were higher by +16.7%, +67.8% and +13.5% in participants with coronavirus, influenza and rhinovirus, respectively, such that RISK11 could not differentiate prevalent tuberculosis from upper respiratory viruses. Compared to RISK11, the Either-Positive test combination decreased diagnostic negative likelihood ratio from 0.7 to 0.3, and prognostic negative likelihood ratio from 0.9 to 0.3, but did not improve upon QuantiFERON alone. Compared to QuantiFERON, the Both-Positive test combination increased diagnostic positive likelihood ratio from 1.3 to 4.7, and prognostic positive likelihood ratio from 1.4 to 2.8, but did not improve upon RISK11 alone. Conclusion RISK11 holds promise as a triage test for tuberculosis. Further optimisation, or development of new signatures is needed to improve discrimination of subclinical tuberculosis, without cough, and to mitigate the impact of viral co-infection. RISK11/QuantiFERON combination testing is not recommended.
dc.identifier.apacitationMulenga, H. (2022). <i>Factors affecting diagnostic and prognostic performance of a transcriptomic signature of risk of tuberculosis in HIV-uninfected South African adults</i>. (). ,Faculty of Health Sciences ,Department of Clinical Laboratory Sciences. Retrieved from http://hdl.handle.net/11427/37673en_ZA
dc.identifier.chicagocitationMulenga, Humphrey. <i>"Factors affecting diagnostic and prognostic performance of a transcriptomic signature of risk of tuberculosis in HIV-uninfected South African adults."</i> ., ,Faculty of Health Sciences ,Department of Clinical Laboratory Sciences, 2022. http://hdl.handle.net/11427/37673en_ZA
dc.identifier.citationMulenga, H. 2022. Factors affecting diagnostic and prognostic performance of a transcriptomic signature of risk of tuberculosis in HIV-uninfected South African adults. . ,Faculty of Health Sciences ,Department of Clinical Laboratory Sciences. http://hdl.handle.net/11427/37673en_ZA
dc.identifier.ris TY - Doctoral Thesis AU - Mulenga, Humphrey AB - Background Host blood transcriptomic signatures, such as RISK11, have potential as tests for diagnosing and predicting tuberculosis. This thesis aimed to review the literature, evaluate host and non-host factors associated with variability of the RISK11 signature and impact on discriminatory performance and evaluate RISK11 performance in combination with tests of Mycobacterium tuberculosis sensitization. Methods A systematic review of discriminatory performance of transcriptomic signatures for tuberculosis was conducted. RISK11, QuantiFERON-TB Gold-Plus and host factors were analysed in a prospective cohort, in which a cross-sectional study of upper respiratory organisms was nested. Effects on RISK11 were quantified using multivariable generalised regression. Discriminatory performance of RISK11, and RISK11/QuantiFERON combinations, were quantified by area under the curve and/or sensitivity and specificity. Results In the literature, one signature (90% sensitivity; 74% specificity) met the minimal criteria for a triage test; one signature (86% sensitivity; 84% specificity) met the minimal criteria for a predictive test. In the prospective cohort, RISK11 scores were higher among individuals with prevalent tuberculosis (+18.90%), night sweats (+14.65%) and incident tuberculosis (+7.29%). Cough was associated with 72.55% higher RISK11 score in prevalent tuberculosis cases. Stratification by cough improved diagnostic performance from area under curve of 0.74 overall, to 0.97 in cough-positive participants. Adjustment for host factors affecting controls did not change RISK11 discriminatory performance. In the cross-sectional study, RISK11 scores were higher by +16.7%, +67.8% and +13.5% in participants with coronavirus, influenza and rhinovirus, respectively, such that RISK11 could not differentiate prevalent tuberculosis from upper respiratory viruses. Compared to RISK11, the Either-Positive test combination decreased diagnostic negative likelihood ratio from 0.7 to 0.3, and prognostic negative likelihood ratio from 0.9 to 0.3, but did not improve upon QuantiFERON alone. Compared to QuantiFERON, the Both-Positive test combination increased diagnostic positive likelihood ratio from 1.3 to 4.7, and prognostic positive likelihood ratio from 1.4 to 2.8, but did not improve upon RISK11 alone. Conclusion RISK11 holds promise as a triage test for tuberculosis. Further optimisation, or development of new signatures is needed to improve discrimination of subclinical tuberculosis, without cough, and to mitigate the impact of viral co-infection. RISK11/QuantiFERON combination testing is not recommended. DA - 2022_ DB - OpenUCT DP - University of Cape Town KW - Pathology LK - https://open.uct.ac.za PY - 2022 T1 - Factors affecting diagnostic and prognostic performance of a transcriptomic signature of risk of tuberculosis in HIV-uninfected South African adults TI - Factors affecting diagnostic and prognostic performance of a transcriptomic signature of risk of tuberculosis in HIV-uninfected South African adults UR - http://hdl.handle.net/11427/37673 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/37673
dc.identifier.vancouvercitationMulenga H. Factors affecting diagnostic and prognostic performance of a transcriptomic signature of risk of tuberculosis in HIV-uninfected South African adults. []. ,Faculty of Health Sciences ,Department of Clinical Laboratory Sciences, 2022 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/37673en_ZA
dc.language.rfc3066eng
dc.publisher.departmentDepartment of Clinical Laboratory Sciences
dc.publisher.facultyFaculty of Health Sciences
dc.subjectPathology
dc.titleFactors affecting diagnostic and prognostic performance of a transcriptomic signature of risk of tuberculosis in HIV-uninfected South African adults
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationlevelPhD
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