Developing and applying serological and molecular skills to the virological analysis of HIV-infected patients from Kumasi, Ghana



Adjei-Asante, Kwabena
Developing and applying serological and molecular skills to the virological analysis of HIV-infected patients from Kumasi, Ghana. Master of Philosophy thesis, University of Liverpool.

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Abstract

Background : Virological monitoring is critical in the management of HIV-infected patients, providing a standard in the assessment of disease prognosis and progression, guiding the initiation of ART and treatment selection, monitoring therapeutic success and establishing treatment failure and drug resistance. The absence of viral load monitoring can impact upon individual and public health through failure to maintain viral suppression, and increased risk of drug resistance. HIV management at the KATH HIV clinic, Kumasi, Ghana, does not include virological monitoring due to the lack of laboratory infrastructure and technical skills, thus the virological response to ART among treated patients at the centre is not fully understood. Moreover, data on the prevalence of HCV infection in both the general population and HIV-positive patients in Ghana are limited, with seroprevalence estimates ranging from 0.5% to 18.7% documented among different Ghanaian populations, possibly due to differences in study populations and the serological assays employed. Furthermore, these previous studies did not attempt confirmation of HCV status by PCR or RIBA. The aim of this study is to determine the HIV virological response in a HIV/HBV co-infected cohort from KATH, ascertain the specificity and sensitivity of commercially available HCV serological assays, and develop an assay that could be used as an alternative for HCV RNA testing in Kumasi. Methods: 247 HIV/HBV co-infected patients attending the KATH HIV clinic were recruited into a prospective HIV and viral hepatitis study, of which HIV-1 viral load was determined for 183 ART-experienced patients at study entry using the Abbott Real Time HIV-1 assay. The HIV-1 viral load detection among patients who had been on ART for at least 24 weeks was assessed. HIV positive samples from KATH with known HCV-RNA status were tested with two automated anti-HCV antibody assays, the Abbott Architect anti-HCV, Vitros Anti-HCV, and two manual EIAs, Monolisa HCV Ag-Ab ULTRA, and the ORTHO HCV 3.0 ELISA System with Enhanced SAVe. Of the last three assays the performance and the respective assay cut-offs likely to be indicative of RNA positivity were evaluated using their PCR and Architect results as reference. The development of an in-house indirect sandwich HCV core antigen EIA which could be used as an alternative for HCV-RNA testing was attempted. Results: Overall, 58/183 (37.4%) patients who received treatment for at least 24 weeks showed a viral load >40 copies/mL with a median level of 826 copies/mL (IQR: 65 - 26752). Their CD4 T-cell counts were lower compared to patients with undetectable viral load (P= 0.002, Mann Whitney U test). Among the four HCV antibody assays the Ortho was found to be the most specific assay that could be employed in a limited resource setting such as Kumasi, and an S/CO ratio of 3.65 was found to be most likely to be indicative of HCV RNA positivity. The HCV core EIA development was not completed in time due to poor activity of commercially available agents. Conclusion: Through this study, skills in HIV viral load and EIA development have been acquired that could be applied to improve virological monitoring at KATH with the necessary infrastructure in place. Further studies are required to identify factors that are associated with poor viral response in this cohort. The ORTHO HCV 3.0 ELISA System with Enhanced SAVe can be regarded as a suitable diagnostic tool for HCV infection in Kumasi, but further studies are required to establish the S/CO ratio most likely to be indicative of HCV RNA positivity.

Item Type: Thesis (Master of Philosophy)
Additional Information: Date: 2013-07 (completed)
Subjects: ?? RC ??
Divisions: Faculty of Health and Life Sciences
Depositing User: Symplectic Admin
Date Deposited: 05 Aug 2014 09:26
Last Modified: 16 Dec 2022 04:41
DOI: 10.17638/00016073
Supervisors:
  • Geretti, Anna Maria
  • Beeching, Nicholas
URI: https://livrepository.liverpool.ac.uk/id/eprint/16073