Outcomes of HIV Infected Individuals After Ten Years on Antiretroviral Treatment

1. INTRODUCTION: 1.1. Disease Setting/Patient Population: Advances in HIV antiretroviral therapy (ART) have dramatically reduced mortality from HIV, primarily because of the reduction in deaths attributable to AIDS defining conditions such that a person receiving state-of-the-art ART may now expect to live 25 years and potentially longer. However the number of deaths attributable to causes not conventionally considered to be HIV related is increasing with up to 50% of all patients with HIV die from causes considered unrelated to HIV. Thus, management of HIV now involves the treatment of chronic diseases with the possibility of near normal life expectancy, but often with multiple co morbidities.

1.2. Background and Rationale: Cardiovascular risk in patients on ART Metabolic complications, including dyslipidemia, insulin resistance, and altered fat distribution (loss of subcutaneous fat and a relative increase in central fat), are common in adults infected with HIV who are receiving ART. These complications may increase these patients' risk of cardiovascular disease. Recent studies suggest that some types of ART may be associated with increased risk of cardiovascular disease, a cause for concern given that people living with HIV may take ART for decades. The mechanisms causing an increased risk of cardiovascular disease are unclear, but it has been suggested that it may relate to dyslipidemia, insulin resistance, diabetes mellitus, inflammation, impaired fibrinolysis, factors specific to antiretroviral medications, or combinations of these factors. Grinspoon and Carr further speculate that both HIV and ART might be associated with many of these risk factors.

From observational data the evidence linking ART and cardiovascular disease has pointed specifically to PIs as a class since they may promote the formation of atherosclerotic lesions, and other NRTI specific agents (abacavir, didanosine). However up to date the role of abacavir remain controversial. All potential cardiovascular risk factors, including dyslipidemia, insulin resistance, hypertension, smoking, sedentary lifestyle, weight, and family history, should be assessed. Ideally glucose levels and fasting lipid levels should be checked annually in all HIV patients on ART.

Renal disease The use of combination, highly active antiretroviral therapy (HAART) since the mid-1990s has resulted in significant and sustained reductions in morbidity and mortality from HIV infection, including significant declines in HIV-associated nephropathy (HIVAN). At the same time, however, a variety of ART-related renal side effects have been noted, including proteinuria and renal tubular damage, interstitial nephritis, nephrolithiasis, and overall declines in glomerular filtration rate. Kidney function has been estimated to be abnormal in up to 30% of HIV-infected patients. In addition, other metabolic complications such as type 2 diabetes and hypertension may also contribute to renal dysfunction over time.

In Sub- Saharan Africa, including Uganda, tenofovir has been included as one of the recommended drugs for first line regimens, due to its comparable efficacy to other first-line regimens containing stavudine, zidovudine or abacavir, and has the additional advantage of low toxicity and availability as a once-daily, fixed-dose generic formulation. Yet concerns regarding its renal tubular toxicity remain especially on its use in resource-limited settings where clinical detection of renal impairment is difficult in. Early stages of renal dysfunction can be are assessed through laboratory monitoring of creatinine and glomerular filtration rate. Current guidelines contraindicate TDF use when creatinine clearance (CrCl) falls below 50 ml/min unless dose reductions are made. If TDF is to be implemented in resource-limited settings where numbers requiring antiretroviral therapy are high but access to laboratory services are scarce, these monitoring protocols may need to be further simplified. Ideally in order to monitor patients for renal toxicity, It is recommended that urinalysis for proteinuria is performed routinely and creatinine clearance calculated; co morbidities that may contribute to elevated risk of kidney disease should be also closely monitored. Data from the DART trial, a prospective randomized clinical trial conducted in an African setting, showed a low (1.3%) rate of severe renal impairment through 96 weeks, with no difference in TDF-containing and non TDF-containing regimens. Similarly data from a routine program setting (Lesotho) shows that renal toxicity due to tenofovir is rare and mild.