Effect of short-course of antiretroviral agents on serum triglycerides of healthy individuals

The implications of pharmacogenomics in the treatment of HIV-1-infected patients of African descent

One of the great advances in the treatment of HIV-1 infection was the development of the highly active antiretroviral therapy (HAART). Although this treatment strategy is highly effective in many individuals, interpatient variability of drug response and high incidences of short- and long-term toxicities remain significant problems associated with this treatment. Logically, pharmacogenetic differences among HIV-1-infected individuals are thought to represent important factors contributing to antiretroviral drug response. Studies have identified polymorphisms in drug-metabolizing enzymes, drug transporters, and most recently the human leukocyte antigen locus that appears to have significant effects on the clinical outcomes of antiretroviral therapy. Furthermore, some studies have shown that many of these crucial polymorphisms are more likely or less likely in certain populations. This review investigates the potential role of pharmacogenomics in the management of HIV-1 infection in people of African descent.

Antiretroviral post-exposure prophylaxis (PEP) for occupational HIV exposure

BACKGROUND

Populations such as healthcare workers (HCWs), injection drug users (IDUs), and people engaging in unprotected sex are all at risk of being infected with the human immunodeficiency virus (HIV). Animal models show that after initial exposure, HIV replicates within dendritic cells of the skin and mucosa before spreading through lymphatic vessels and developing into a systemic infection (CDC 2001). This delay in systemic spread leaves a "window of opportunity" for post-exposure prophylaxis (PEP) using antiretroviral drugs designed to block replication of HIV (CDC 2001). PEP aims to inhibit the replication of the initial inoculum of virus and thereby prevent establishment of chronic HIV infection.

OBJECTIVES

To evaluate the effects of antiretroviral PEP post-occupational exposure to HIV.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, AIDSearch, and the Database of Abstracts of Reviews of Effectiveness were searched from 1985 to January 2005 to identify controlled trials. There were no language restrictions. Because no controlled clinical trials were retrieved, the search was repeated on 31 May 2005 in MEDLINE, AIDSearch and EMBASE using a search strategy to identify analytic observational studies. Handsearches of the reference lists of all pertinent reviews and studies found were also undertaken. Experts in the field of HIV prevention were contacted.

SELECTION CRITERIA

Types of studies: All controlled trials (including randomized clinical trials and controlled clinical trials). If no controlled trials were found, analytic studies (e.g. cohort and case-control studies) were considered. Descriptive studies (i.e. studies with no comparison groups) were excluded. Types of participants included:HCWs exposed to any known or potentially HIV contaminated product;anyone exposed to a needlestick contaminated by known or potentially HIV-infected blood or other bodily fluid in an occupational setting; andanyone exposed through the mucous membranes to an HIV-infected or potentially infected substance in occupational setting.Excluded: Sex workers (PEP post-sexual exposure is addressed in another Cochrane review (Martín 2005)). Types of interventions: Any intervention that administered single or combinations of antiretrovirals as PEP to people exposed to HIV through percutaneous injuries and/or occupational mucous membrane exposures when the HIV status of the source patient was positive or unknown. Studies comparing two types of PEP regimens were considered, as were studies comparing PEP with no intervention. Types of outcome measures:Incidence of HIV infection in those given PEP versus those given placebo or a different PEP regimen; Adherence to PEP; Complications of PEPTypes of outcome measures: Incidence of HIV infection in those given PEP versus those given placebo or a different PEP regimen; Adherence to PEP; Complications of PEP DATA COLLECTION AND ANALYSIS: Data concerning outcomes, details of the interventions, and other study characteristics were extracted by two independent authors (TY and JA) using a standardized data extraction form (Table 04). A third author (GK) resolved disagreements. The following information was gathered from each included study: location of study, date, publication status, demographics (e.g. age, gender, occupation, risk behavior, etc.) of participants/exposure modality, form of PEP used, duration of use, and outcomes. Odds ratios with a 95% confidence interval (CI) were used as the measure of effect. A meta-analysis was performed for adverse events where two-drug regimens were compared with three-drug regimens. Due to overlap between Puro 2000 and Puro 2005, the former was not included in the combined analysis.

MAIN RESULTS

Effect of PEP on HIV seroconversionNo randomized controlled trials were identified. Only one case-control study was included. HIV transmission was significantly associated with deep injury (OR 15, 95% CI 6.0 to 41), visible blood on the device (OR 6.2, 95% CI 2.2 to 21), procedures involving a needle placed in the source patient's blood vessel (OR 4.3, 95% CI 1.7 to 12), and terminal illness in the source patient (OR 5.6, 95% CI 2.0 to 16). After controlling for these risk factors, no differences were detected in the rates at which cases and controls were offered post-exposure prophylaxis with zidovudine. However, cases had significantly lower odds of having taken zidovudine after exposure compared to controls (OR 0.19, 95%CI 0.06 to 0.52). No studies were found that evaluated the effect of two or more antiretroviral drugs for occupational PEP. Adherence to and complications with PEPEight reports from observational comparative studies confirmed findings that adverse events were higher with a three-drug regimen, especially one containing indinavir. However, discontinuation rates were not significantly different.

AUTHORS' CONCLUSIONS

The use of occupational PEP is based on limited direct evidence of effect. However, it is highly unlikely that a definitive placebo-controlled trial will ever be conducted, and, therefore, on the basis of results from a single case-control study, a four-week regimen of PEP should be initiated as soon as possible after exposure, depending on the risk of seroconversion. There is no direct evidence to support the use of multi-drug antiretroviral regimens following occupational exposure to HIV. However, due to the success of combination therapies in treating HIV-infected individuals, a combination of antiretroviral drugs should be used for PEP. Healthcare workers should be counseled about expected adverse events and the strategies for managing these. They should also be advised that PEP is not 100% effective in preventing HIV seroconversion. A randomized controlled clinical trial is neither ethical nor practical. Due to the low risk of HIV seroconversion, a very large sample size would be required to have enough power to show an effect. More rigorous evaluation of adverse events, especially in the developing world, are required. Seeing that current practice is partly based on results from individual primary animal studies, we recommend a formal systematic review of all relevant animal studies.

Associations among race/ethnicity, ApoC-III genotypes, and lipids in HIV-1-infected individuals on antiretroviral therapy

BACKGROUND

Protease inhibitors (PIs) are associated with hypertriglyceridemia and atherogenic dyslipidemia. Identifying HIV-1-infected individuals who are at increased risk of PI-related dyslipidemia will facilitate therapeutic choices that maintain viral suppression while reducing risk of atherosclerotic diseases. Apolipoprotein C-III (apoC-III) gene variants, which vary by race/ethnicity, have been associated with a lipid profile that resembles PI-induced dyslipidemia. However, the association of race/ethnicity, or candidate gene effects across race/ethnicity, with plasma lipid levels in HIV-1-infected individuals, has not been reported.

METHODS AND FINDINGS

A cross-sectional analysis of race/ethnicity, apoC-III/apoA-I genotypes, and PI exposure on plasma lipids was performed in AIDS Clinical Trial Group studies (n = 626). Race/ethnicity was a highly significant predictor of plasma lipids in fully adjusted models. Furthermore, in stratified analyses, the effect of PI exposure appeared to differ across race/ethnicity. Black/non-Hispanic, compared with White/non-Hispanics and Hispanics, had lower plasma triglyceride (TG) levels overall, but the greatest increase in TG levels when exposed to PIs. In Hispanics, current PI antiretroviral therapy (ART) exposure was associated with a significantly smaller increase in TGs among patients with variant alleles at apoC-III-482, -455, and Intron 1, or at a composite apoC-III genotype, compared with patients with the wild-type genotypes.

CONCLUSIONS

In the first pharmacogenetic study of its kind in HIV-1 disease, we found race/ethnic-specific differences in plasma lipid levels on ART, as well as differences in the influence of the apoC-III gene on the development of PI-related hypertriglyceridemia. Given the multi-ethnic distribution of HIV-1 infection, our findings underscore the need for future studies of metabolic and cardiovascular complications of ART that specifically account for racial/ethnic heterogeneity, particularly when assessing candidate gene effects.

Post-exposure prophylaxis of HIV infection in healthcare workers: recommendations for the European setting

The European Commission funded a project for the standardisation of the management of occupational exposures to HIV/blood-borne infections and antiretroviral post-exposure prophylaxis (PEP) in Europe. Within this project, the following recommendations and rationale were formulated by experts representative of participating countries. Based on assessment of the exposure, material, and source characteristics, PEP should be started as soon as possible with any triple combination of antiretrovirals approved for the treatment of HIV-infected patients; initiation is discouraged after 72 hours Rapid HIV testing of the source could reduce inappropriate PEP. HIV testing should be performed at baseline, 4, 12, and 24 weeks, with additional clinical and laboratory monitoring of adverse reactions and potential toxicity at week 1 and 2. HIV resistance tests in the source and direct virus assays in the exposed HCW are not recommended routinely. These easy-to-use recommendations seek to maximise PEP effect while minimising its toxicity and inappropriate use.

HIV-related lipodystrophy and related factors

As new therapies for HIV infection have been developed, some of the clinical focus related to AIDS and HIV infection has shifted from acute care, to more chronic issues. Some of these new clinical issues seem related to the HIV infection itself, while others seem to be side effects of therapeutic efforts. Metabolic abnormalities, such as dyslipidemia, insulin resistance, and lipodystrophy (LD) have been observed. The clinical importance of these is demonstrated by the increased prevalence of cardiovascular disease and diabetes in HIV infected persons. LD is a general term used to describe varying degrees of fat redistribution, including lipoatrophy and lipohypertrophy, in different body regions. Though LD was observed in persons with HIV infection before highly active treatment regimens were developed, the prevalence of LD has seemingly increased drastically with the widespread use of more active therapies. It has been postulated that protease inhibitors (PI), especially, are linked to the development of LD. This review will assess the epidemiologic information related to HIV-associated LD, and related metabolic syndromes. In addition, potential mechanisms accounting for these syndromes will be reviewed. In general, the available data do not define a single, definable etiology or mechanism explaining these clinical conditions, but suggest that these conditions are caused by a complex interaction potentially involving such things as the side effects of medications, alteration of immune function, and individual subject characteristics, such as body weight and baseline lipid level.

Metabolic and Immunological Effects of Antiretroviral Agents in Healthy Individuals Receiving Post-Exposure Prophylaxis

We have assessed metabolic and immunological effects of a nelfinavir-containing regimen in healthy HIV-1-uninfected individuals receiving post-exposure prophylaxis. Our data suggest that this regimen is well tolerated and did not modify the lipid or hepatic profiles. This antiretroviral regimen seems to have no effect on lymphocyte T cell subsets, however, it could have an immune-modulator role, inducing an increase in the proliferative responses to mitogens.

Metabolic and morphologic disorders in patients treated with highly active antiretroviral therapy since primary HIV infection

Our objective was to describe morphologic and metabolic disorders in patients treated with highly active antiretroviral therapy (HAART) since primary HIV infection (PHI). Our method was prospective evaluation of patients with PHI initiating HAART at the time of diagnosis. Outcome measures were: development of hyperglycemia, hypercholesterolemia, hypertriglyceridemia, and of body shape abnormalities indicative of lipodystrophy, assessed through self-reported questionnaires and physical examination.

RESULTS

From May 1997 to April 2001, 41 patients (35 males) with PHI presented at the National Institute for Infectious Diseases "Lazzaro Spallanzani" in Rome, Italy. A protease inhibitor-including regimen was started in 30 patients, and a nonnucleoside reverse transcriptase-inhibitor in 11. Median interval between enrollment and treatment initiation was 30 days (mean 39, range 10-150). Median HAART duration was 19 months (mean 21.2, range 3-47). Thirty-eight patients had undetectable (less than 80 cp/mL) HIV RNA after a median of 3 months (mean 4.1, range 1-15). Mean CD4 cells count increased from 632/mmc at baseline to 936/mmc at the last follow up. No cases of hyperglycemia (glucose level greater than 110 mg/dL) were observed. After a median of 6 months on HAART, 10 patients developed beyond grade 2 (greater than 240 mg/dL) hypercholesterolemia, 5 developed beyond grade 2 (greater than 400 mg/dL) hypertrygliceridemia, and two developed both. Body mass index did not change significantly. Five patients (12.2%) developed lipodystrophy after a median of 14.5 months (mean 15.3, range 2-30), with an incidence of 7.3 per 100 patient-years.

CONCLUSIONS

Dyslipidemia and lipodystrophy can occur in patients treated with HAART since PHI. This risk of should be taken into account when considering this early antiretroviral treatment of HIV infection.

Strategies for treating HIV-related lipodystrophy

HIV-related lipodystrophy has emerged as one of the most prevalent problems for patients with HIV, since this infection can now be seen as a chronic disease. Despite its growing importance, crucial issues such as aetiopathogenesis, diagnosis, prevention and therapy remain largely unknown and unexplored. Current evidence suggests that aetiology is multifactorial. HIV infection, antiretroviral therapy and patient-related factors probably all contribute to the development of lipodystrophy. The lack of a formal definition and the nature of wasting syndromes that affect HIV-infected patients can hinder the diagnosis and treatment of lipodystrophy. Body fat changes have a major negative impact on the quality of life of patients. Metabolic abnormalities are also well known cardiovascular risk factors that can increase the morbidity and mortality due to cardiovascular disorders in a relatively young population. As yet, we do not know whether lipodystrophy is preventable or reversible. Several therapeutic approaches have been tested with limited success, however potential complications must be considered. These therapeutic approaches include general health measures (diet, exercise and discontinuation of smoking), switching antiretrovirals (from protease inhibitors to non-nucleoside reverse transcriptase inhibitors or abacavir, or from stavudine to other nucleoside reverse transcriptase inhibitors) and use of drugs with metabolic effects (metformin, thiazolidinediones, recombinant growth hormone and anabolic steroids). A judicious use of available data, and opting for an individualised approach seems the best option for management of this problem at present.

Antiretroviral Therapy and the Lipodystrophy Syndrome

‘Lipodystrophy syndrome’ in the setting of HIV infection has come to encompass a collection of morphological and metabolic abnormalities linked with the use of antiretroviral therapy and other risk factors. We review the clinical literature on this subject as it has evolved historically, taking pertinent methodological issues into account.