Antiretroviral therapy in the management of HIV/AIDS

Antiretroviral therapy is the standard of care for the treatment of human immunodeficiency virus (HIV) infection and current guidelines recommend the use of a combination of antiretroviral drugs (combination antiretroviral therapy, cART). This thesis describes clinical research that examined aspects of HIV disease progression during use of cART, immunological responses to long-term treatment with cART, and interventions for poor immunological responses during virologically successful cART. The body of work commences with an exploration of literature on HIV natural history, pathogenesis and antiretroviral therapy. Chapter three summarises predictors of HIV-1 disease progression in patients initiating cART with advanced disease in a South-East Asian cohort. The evolution of CD4+ T-cell counts in patients on long-term suppressive cART is described in chapter four. More than 50% of patients exhibited a constant rate of CD4+ T-cell increase even after six years of cART. CD4+ T-cell percentage at the start of cART was a predictor of time to a CD4+ T-cell set-point. In chapter five, associations between exposure to individual nucleoside analogue reverse transcriptase inhibitors (NRTIs) as part of cART regimen and CD4+ T-cell outcomes for individuals on long-term suppressive cART were investigated in a retrospective cohort study. Long-term exposure to NRTIs did not significantly affect recovery of CD4+ T-cell counts, even in patients initiating therapy with advanced disease. Chapter six is a review of literature on chronic inflammation and immune activation in HIV-1. These two features of HIV-1 infection have been well defined for many years but only recently a putative connection between these observations and a direct role in the immunopathogenesis of HIV disease has been proposed. Chapter seven describes the design, execution and findings from a randomised double-blind, placebo-controlled study that examined two therapeutic interventions in patients with sub-optimal CD4+ T-cell recovery despite sustained virologic suppressive cART. Neither raltegravir intensification nor addition of hyperimmune bovine colostrum to a cART regimen resulted in significant increases in CD4+ T-cell count or demonstrable changes in plasma microbial translocation markers, plasma HIV-RNA levels or T-cell activation. Finally, a summary of findings, general discussion and conclusions are presented in chapter eight

Clinical use of HIV integrase inhibitors : a systematic review and meta-analysis

Background: Optimal regimen choice of antiretroviral therapy is essential to achieve long-term clinical success. Integrase inhibitors have swiftly been adopted as part of current antiretroviral regimens. The purpose of this study was to review the evidence for integrase inhibitor use in clinical settings. Methods: MEDLINE and Web-of-Science were screened from April 2006 until November 2012, as were hand-searched scientific meeting proceedings. Multiple reviewers independently screened 1323 citations in duplicate to identify randomized controlled trials, nonrandomized controlled trials and cohort studies on integrase inhibitor use in clinical practice. Independent, duplicate data extraction and quality assessment were conducted. Results: 48 unique studies were included on the use of integrase inhibitors in antiretroviral therapy-naive patients and treatment-experienced patients with either virological failure or switching to integrase inhibitors while virologically suppressed. On the selected studies with comparable outcome measures and indication (n = 16), a meta-analysis was performed based on modified intention-to-treat (mITT), on-treatment (OT) and as-treated (AT) virological outcome data. In therapy-naive patients, favorable odds ratios (OR) for integrase inhibitor-based regimens were observed, (mITT OR 0.71, 95% CI 0.59-0.86). However, integrase inhibitors combined with protease inhibitors only did not result in a significant better virological outcome. Evidence further supported integrase inhibitor use following virological failure (mITT OR 0.27; 95% CI 0.11-0.66), but switching to integrase inhibitors from a high genetic barrier drug during successful treatment was not supported (mITT OR 1.43; 95% CI 0.89-2.31). Integrase inhibitor-based regimens result in similar immunological responses compared to other regimens. A low genetic barrier to drug-resistance development was observed for raltegravir and elvitegravir, but not for dolutegravir. Conclusion: In first-line therapy, integrase inhibitors are superior to other regimens. Integrase inhibitor use after virological failure is supported as well by the meta-analysis. Careful use is however warranted when replacing a high genetic barrier drug in treatment-experienced patients switching successful treatment

Service delivery challenges in HIV care during the first year of the COVID-19 pandemic: results from a site assessment survey across the global IeDEA consortium.

INTRODUCTION Interruptions in treatment pose risks for people with HIV (PWH) and threaten progress in ending the HIV epidemic; however, the COVID-19 pandemic's impact on HIV service delivery across diverse settings is not broadly documented. METHODS From September 2020 to March 2021, the International epidemiology Databases to Evaluate AIDS (IeDEA) research consortium surveyed 238 HIV care sites across seven geographic regions to document constraints in HIV service delivery during the first year of the pandemic and strategies for ensuring care continuity for PWH. Descriptive statistics were stratified by national HIV prevalence (<1%, 1-4.9% and ≥5%) and country income levels. RESULTS Questions about pandemic-related consequences for HIV care were completed by 225 (95%) sites in 42 countries with low (n = 82), medium (n = 86) and high (n = 57) HIV prevalence, including low- (n = 57), lower-middle (n = 79), upper-middle (n = 39) and high- (n = 50) income countries. Most sites reported being subject to pandemic-related restrictions on travel, service provision or other operations (75%), and experiencing negative impacts (76%) on clinic operations, including decreased hours/days, reduced provider availability, clinic reconfiguration for COVID-19 services, record-keeping interruptions and suspension of partner support. Almost all sites in low-prevalence and high-income countries reported increased use of telemedicine (85% and 100%, respectively), compared with less than half of sites in high-prevalence and lower-income settings. Few sites in high-prevalence settings (2%) reported suspending antiretroviral therapy (ART) clinic services, and many reported adopting mitigation strategies to support adherence, including multi-month dispensing of ART (95%) and designating community ART pick-up points (44%). While few sites (5%) reported stockouts of first-line ART regimens, 10-11% reported stockouts of second- and third-line regimens, respectively, primarily in high-prevalence and lower-income settings. Interruptions in HIV viral load (VL) testing included suspension of testing (22%), longer turnaround times (41%) and supply/reagent stockouts (22%), but did not differ across settings. CONCLUSIONS While many sites in high HIV prevalence settings and lower-income countries reported introducing or expanding measures to support treatment adherence and continuity of care, the COVID-19 pandemic resulted in disruptions to VL testing and ART supply chains that may negatively affect the quality of HIV care in these settings

Factors influencing the normalization of CD4+ T-cell count, percentage and CD4+/CD8+ T-cell ratio in HIV-infected patients on long-term suppressive antiretroviral therapy

AbstractWe evaluated factors associated with normalization of the absolute CD4+ T-cell counts, per cent CD4+ T cells and CD4+/CD8+ T-cell ratio. A multicentre observational study was carried out in patients with sustained HIV-RNA <50 copies/mL. Outcomes were: CD4-count >500/mm3 and multiple T-cell marker recovery (MTMR), defined as CD4+ T cells >500/mm3 plus %CD4 T cells >29% plus CD4+/CD8+ T-cell ratio >1. Kaplan-Meier survival analysis and Cox regression analyses to predict odds for achieving outcomes were performed. Three hundred and fifty-two patients were included and followed-up for a median of 4.1 (IQR 2.1–5.9) years, 270 (76.7%) achieving a CD4+ T-cell count >500 cells/mm3 and 197 (56%) achieving MTMR. Using three separate Cox models for both outcomes we demonstrated that independent predictors were: both absolute CD4+ and CD8+ T-cell counts, %CD4+ T cells, a higher CD4+/CD8+ T-cell ratio, and age. A likelihood-ratio test showed significant improvements in fitness for the prediction of either CD4+ >500/mm3 or MTMR by multivariable analysis when the other immune markers at baseline, besides the absolute CD4+ count alone, were considered. In addition to baseline absolute CD4+ T-cell counts, pretreatment %CD4+ T cells and the CD4+/CD8+ T-cell ratio influence recovery of T-cell markers, and their consideration should influence the decision to start antiretroviral therapy. However, owing to the small sample size, further studies are needed to confirm these results in relation to clinical endpoints