Switching effective antiretroviral therapy: a review

Decoupling HIV-1 antiretroviral drug inhibition from plasma antibody activity to evaluate broadly neutralizing antibody therapeutics and vaccines

The development of broadly neutralizing antibody (bnAb)-based therapeutic HIV-1 vaccines and cure concepts depends on monitoring bnAb plasma activity in people with HIV (PWH) on suppressive antiretroviral therapy (ART). To enable this, analytical strategies must be defined to reliably distinguish antibody-based neutralization from drug inhibition. Here, we explore strategies that either utilize drug-resistant viruses or remove drugs from plasma. We develop ART-DEX (ART dissociation and size exclusion), an approach which quantitatively separates drugs from plasma proteins following pH-triggered release allowing accurate definition of antibody-based neutralization. We demonstrate that ART-DEX, alone or combined with ART-resistant viruses, provides a highly effective and scalable means of assessing antibody neutralization during ART. Implementation of ART-DEX in standard neutralization protocols should be considered to enhance the analytical capabilities of studies evaluating bnAb therapeutics and therapeutic vaccines, furthering the development of advanced ART and HIV-1 cure strategies.

Comparison of Switching Between Antiretroviral Agents Versus Introducing Lipid-lowering Agents for HAART-induced Dyslipidemia

PURPOSE

Highly active antiretroviral therapy (HAART) has brought a significant reduction in HIV/AIDS-related morbidity and mortality. However, metabolic abnormalities (eg, dyslipidemias) have continued to pose significant challenges, warranting a switch between antiretroviral agents and/or the introduction of a statin. Hence, the purposes of this study was to compare the efficacy of switching between antiretroviral agents versus introducing a statin in the long-term management of HAART-induced dyslipidemia in people living with HIV, and to identify the most potent agent in switching therapies.

METHODS

A comprehensive literature search of PubMed and Medline identified articles published from the years 2000 to 2020 in the English language, resulting in 84 articles, 30 of which were selected based on inclusion and exclusion criteria. Information on primary and secondary outcomes was extracted. Statistical analysis was done on the variables, and the differences between groups were considered significant at P < 0.05.

FINDINGS

Statin use was associated with significant reductions in triglycerides and total cholesterol (TC) at 6 weeks (both, P < 0.01). A switch of antiretroviral agents was associated with gradual reductions in TC and triglycerides for up to 48 weeks (both, P < 0.01). Statin use was associated with a reduced CD4 count at 24 weeks (P < 0.01). A switch of antiretroviral agents was associated with an increased CD4 count at 48 weeks (P < 0.01).

IMPLICATIONS

Statins were as effective as switching antiretroviral therapies in the short-term management of TC and triglycerides in patients with HAART-induced dyslipidemia.

Management of Antiretroviral Therapy with Boosted Protease Inhibitors-Darunavir/Ritonavir or Darunavir/Cobicistat

A major challenge in the management of antiretroviral therapy (ART) is to improve the patient's adherence, reducing the burden caused by the high number of drugs that compose the treatment regimens for human immunodeficiency virus positive (HIV+) patients. Selection of the most appropriate treatment regimen is responsible for therapeutic success and aims to reduce viremia, increase the immune system response capacity, and reduce the incidence rate and intensity of adverse reactions. In general, protease inhibitor (PI) is one of the pillars of regimens, and darunavir (DRV), in particular, is frequently recommended, along with low doses of enzyme inhibitors as cobicistat (COBI) or ritonavir (RTV), by the international guidelines. The potential of clinically significant drug interactions in patients taking COBI or RTV is high due to the potent inhibitory effect on cytochrome CYP 450, which attracts significant changes in the pharmacokinetics of PIs. Regardless of the patient or type of virus, the combined regimens of DRV/COBI or DRV/RTV are available to clinicians, proving their effectiveness, with a major impact on HIV mortality/morbidity. This study presents current information on the pharmacokinetics, pharmacology, drug interactions, and adverse reactions of DRV; it not only compares the bioavailability, pharmacokinetic parameters, immunological and virological responses, but also the efficacy, advantages, and therapeutic disadvantages of DRV/COBI or DRV/RTV combinations.

The New NNRTI ACC007 Combined with Lamivudine and Tenofovir Disoproxil Fumarate Show Synergy Anti-HIV Activity In Vitro

BACKGROUND

Acquired immunodeficiency syndrome can hardly be cured currently and people with human immunodeficiency virus (HIV) need lifelong treatment that may result in the emergence of drug resistance which leads to failed treatment. Thus, the development of new anti- HIV drugs and new treatment regimens are necessary.

OBJECTIVE

The aim of this study is to analyze the combined anti-HIV activity of tenofovir disoproxil fumarate, lamivudine and ACC007, a new non-nucleoside reverse transcriptase inhibitor.

METHODS

The antiviral activity of tenofovir disoproxil fumarate, lamivudine and ACC007 alone or in combination against different HIV-1 strains was determined by the detection of HIV-1 p24 level through enzyme-linked immunosorbent assay.

RESULT

ACC007 showed EC50 of nanomolar range (from 3.03 nM to 252.59 nM) against all HIV-1 strains used in this study except the HIV-1A17, with EC50 of 1.57 μM. The combined antiviral activity of ACC007, lamivudine and tenofovir disoproxil fumarate showed synergy antiviral activity against all HIV-1 strains used in this study. The three-drug combination showed moderate synergism against HIV-1A17, HIV-14755-5, HIV-1K103N and HIV-1V106M, with a combination index value ranging from 0.71 to 0.87, and showed synergism against the other HIV-1 strains with combination index value from 0.35 to 0.67. The combination with ACC007 significantly increases the dose reduction index value of lamivudine and tenofovir disoproxil fumarate, compared with two-drug combination.

CONCLUSION

ACC007 exhibits potent antiviral activity alone or with 3TC and TDF, and exerts synergistic effect against all HIV strains used in our investigation in vitro.

Economic Outcomes of First-Line Regimen Switching Among Stable Patients with HIV

BACKGROUND

Although switching of antiretroviral therapy (ART) is a valid approach for addressing treatment failure in patients with human immunodeficiency virus (HIV), ART changes among those who are well maintained on their current regimens may lead to the development of new side effects or resistance.

OBJECTIVE

To examine the effect of first-line regimen switching on subsequent health care utilization and cost among stable HIV patients.

METHODS

This was a retrospective claims data study of adult patients with HIV who initiated ART between 2007 and 2013 and had been treated with their initial regimens for at least 6 continuous months. Those with evidence of pregnancy or HIV-2 were excluded. Patients who underwent an ART change were assigned to a switcher cohort; a nonswitcher cohort was then generated by matching up to 20 nonswitchers for each switcher, with replacement. The index date was the date of the first ART change for switchers and was the claim date closest to the corresponding switcher's switch date for nonswitchers. Patient characteristics at baseline and post-index annualized health care utilization and costs were analyzed descriptively and with multivariable models. Analyses were performed in the full population and among patients designated as virologically stable (had undetectable viral ribonucleic acid [RNA] for 90 days pre-index) and virologically and clinically stable (had undetectable viral RNA and no apparent clinical reason for switching ART).

RESULTS

The study population consisted of 6,983 individuals, which included 927 switchers (168 virologically stable; 55 virologically+clinically stable), who were matched with replacement with 18,511 nonswitcher comparators. The switcher cohort was 88.8% male (mean age 43.8 years). Mean preindex and follow-up treatment durations for switchers and nonswitchers were 1.8 years and 1.5 years, respectively; demographic characteristics, pre-index treatment duration, and follow-up duration were similar between cohorts. Significantly more nonswitchers than switchers had a first-line efavirenz-based regimen (67.2% vs. 47.8%, P < 0.001). In the virologically stable subset, follow-up annualized health care utilization for switchers versus nonswitchers, respectively, was 14.8 versus 12.3 ambulatory visits (P < 0.05), 0.8 versus 0.9 emergency department visits (P = 0.652), and 0.05 versus 0.05 inpatient hospitalizations (P = 0.915). Follow-up annualized health care costs were $37,120 for switchers versus $31,771 for nonswitchers (P < 0.05), with the difference driven largely by pharmacy costs. Multivariable-adjusted follow-up annualized health care costs were 8.9% higher among switchers versus nonswitchers (P < 0.01), and switchers also had a shorter time to subsequent ART regimen change (P < 0.001). Results were similar for the virologically+clinically stable subset.

CONCLUSIONS

In this large, real-world population, stable patients with HIV who switched from their first-line ART regimens had significantly higher health care costs than those who did not change therapies, suggesting that ART regimen changes may be costly and should be undertaken only when clinically warranted.

DISCLOSURES

This work was funded by Bristol-Myers Squibb (BMS), which participated in the design of the study, interpretation of the data, revision of the manuscript, and the decision to submit the manuscript for publication. Rosenblatt is an employee and stock owner of BMS; Villasis-Keever was an employee of BMS at the time this study was conducted and is currently an employee of Janssen. Buikema is an employee and stock owner of Optum, and Seare, Bengston, Johnson, and Cao are employees of Optum, which was contracted by BMS to conduct the study. Optum contracts with pharmaceutical companies, such as Janssen, Merck, EMD Serano, GlaxoSmithKline, and Gilead, to conduct research in HIV. Optum is also a subsidiary of a health plan that has interest in managing the health and associated costs of patients with HIV. Study concept and design were contributed by Rosenblatt and Buikema, along with the other authors. Cao and Johnson took the lead in data collection, along with Buikema, Seare, and Bengston. Data interpretation was performed by Buikema, Seare, Bengston, and Villasis-Keever. The manuscript was written by Buikema and Bengston, along with Rosenblatt, Seare, Johnson and Villasis-Keever, and revised by Rosenblatt, Villasis-Keever, and Johnson, along with the other authors.

Long-Term Changes of Subcutaneous Fat Mass in HIV-Infected Children on Antiretroviral Therapy: A Retrospective Analysis of Longitudinal Data from Two Pediatric HIV-Cohorts

OBJECTIVE

Longitudinal studies objectively evaluating changes in regional fat distribution of HIV-infected children assessed by whole body dual energy X-ray absorptiometry (DEXA) are scarce, whilst this long-term effect of HIV and antiretroviral therapy (cART) is an important issue in infected children in need for lifelong treatment.

METHODS

We assessed regional fat distribution over time, measured with sequential DEXA-scans in HIV-infected children on cART in cohorts from South Africa (SA) and the Netherlands (NL), and in healthy controls (SA). Limb and trunk fat Z-scores were calculated with the lambda-mu-sigma (LMS) method. Multivariable linear regression models with mixed effects were used to investigate the effect of cART compounds on body fat distribution over time.

RESULTS

In total, 218 children underwent 445 DEXA assessments with a median follow-up of 3.5 years. Fat mass in all limbs was decreased in HIV-infected children compared to controls (arm fat Z-score: coefficient -0.4813; P = 0.006, leg fat Z-score: coefficient -0.4345; P = 0.013). In the HIV-infected group, stavudine treatment was associated with lower subcutaneous fat mass (arm fat Z-score: coefficient -0.5838; P = 0.001), with an additional cumulative exposure effect (arm fat Z-score: coefficient -0.0867; P = 0.003).

CONCLUSIONS

Our study shows that subcutaneous fat loss is still prevalent in HIV-infected children on cART, and is strongly associated with cumulative stavudine exposure. These results underline the need for early detection of subcutaneous fat loss and alternative treatment options for HIV-infected children globally.

HIV-1 Tat immunization restores immune homeostasis and attacks the HAART-resistant blood HIV DNA: results of a randomized phase II exploratory clinical trial

BACKGROUND

The phase II multicenter, randomized, open label, therapeutic trial (ISS T-002, Clinicaltrials.gov NCT00751595) was aimed at evaluating the immunogenicity and the safety of the biologically active HIV-1 Tat protein administered at 7.5 or 30 μg, given 3 or 5 times monthly, and at exploring immunological and virological disease biomarkers. The study duration was 48 weeks, however, vaccinees were followed until the last enrolled subject reached the 48 weeks. Reported are final data up to 144 weeks of follow-up. The ISS T-002 trial was conducted in 11 clinical centers in Italy on 168 HIV positive subjects under Highly Active Antiretroviral Therapy (HAART), anti-Tat Antibody (Ab) negative at baseline, with plasma viremia <50 copies/mL in the last 6 months prior to enrollment, and CD4(+) T-cell number ≥200 cells/μL. Subjects from a parallel observational study (ISS OBS T-002, Clinicaltrials.gov NCT0102455) enrolled at the same clinical sites with the same criteria constituted an external reference group to explore biomarkers of disease.

RESULTS

The vaccine was safe and well tolerated and induced anti-Tat Abs in most patients (79%), with the highest frequency and durability in the Tat 30 μg groups (89%) particularly when given 3 times (92%). Vaccination promoted a durable and significant restoration of T, B, natural killer (NK) cells, and CD4(+) and CD8(+) central memory subsets. Moreover, a significant reduction of blood proviral DNA was seen after week 72, particularly under PI-based regimens and with Tat 30 μg given 3 times (30 μg, 3x), reaching a predicted 70% decay after 3 years from vaccination with a half-life of 88 weeks. This decay was significantly associated with anti-Tat IgM and IgG Abs and neutralization of Tat-mediated entry of oligomeric Env in dendritic cells, which predicted HIV-1 DNA decay. Finally, the 30 μg, 3x group was the only one showing significant increases of NK cells and CD38(+)HLA-DR(+)/CD8(+) T cells, a phenotype associated with increased killing activity in elite controllers.

CONCLUSIONS

Anti-Tat immune responses are needed to restore immune homeostasis and effective anti-viral responses capable of attacking the virus reservoir. Thus, Tat immunization represents a promising pathogenesis-driven intervention to intensify HAART efficacy.

Coronary Heart Disease Risk, Dyslipidemia, and Management in HIV-Infected Persons

Dyslipidemia and coronary heart disease (CHD) are of increasing concern in persons with human immunodeficiency virus (HIV) infection who are living longer because of the benefits of highly active antiretroviral therapy (HAART). All classes of drugs used in HAART have been associated with atherogenic changes in lipid profiles. The management of HIV-infected persons with dyslipidemia and/or CHD currently emphasizes the importance of monitoring and optimizing lipid levels through lifestyle changes, switching antiretrovirals (ARVs), and lipid-lowering treatments utilizing guidelines developed for persons without HIV infection. In HIV-infected persons, the use of lipid-lowering drugs may result in pharmacokinetic interactions with ARVs, complicating the management of patients. Recent advances in our understanding of the differential effects of specific ARVs on lipids is beginning to alter the clinical approach to management. In the absence of randomized clinical trials, clinicians should aggressively treat atherogenic dyslipidemia by primarily utilizing or switching to ARVs with the lowest potential to induce CHD or, when this is not possible or is ineffective, secondarily by the addition of lipid-lowering therapy. The current optimal management of HIV infection requires careful selection of ARVs with consideration given to the potential development of CHD and an understanding of how to manage dyslipidemia.

Atherosclerotic Cardiovascular Disease Risk in the HAART-Treated HIV-1 Population

Atherosclerotic cardiovascular disease (CVD), a leading cause of morbidity and mortality in the general population, is also an increasing cause for concern for HIV-infected patients. A number of risk factors for CVD are also associated with HIV disease and HIV therapy, particularly insulin resistance, metabolic dyslipidemia, and inflammation. For example, atherogenic dyslipidemia, a side effect of HIV therapy, is an established risk for CVD in the non-HIV-infected population. As our understanding of atherosclerotic disease evolves, new markers of CVD risk have been identified, including metabolic syndrome definitions and C-reactive protein, a marker of inflammation. Use of these markers, in association with established risk factor guidelines, may serve as important tools in helping HIV physicians implement drug regimens that allow optimum management of metabolic complications associated with HIV and HAART, and thereby reduce CVD risk. The objective of this article is to review the mechanisms of atherosclerotic CVD and to discuss risk factors and markers that can be applied in the evaluation and treatment of CVD in the HIV-positive population.

Patterns and Predictors of First-Line Antiretroviral Therapy Modification in HIV-1-Infected Adults in a Large Urban Outpatient Cohort in Nigeria

OBJECTIVE

We described the magnitude, type, and factors associated with first-line antiretroviral therapy (ART) modification in HIV-1-infected adults on ART in Jos, Nigeria.

METHOD

Data on 6309 patients initiated on first-line ART between January 2004 and December 2006 were analyzed retrospectively. Factors predictive of modification to initial ART were assessed by chi-square and multivariable logistic regression analysis.

RESULTS

Overall, 5212 (83%) included patients incurred a modification (73.3% drug substitution and 9.7% drug switch) to their initial first-line ARV regimen during a median (interquartile range) follow-up period of 7 (3-8) years. Drug substitutions of zidovudine (ZDV) were less likely than of tenofovir (TDF; adjusted odd ratio [AOR] 0.6; 95% confidence interval [CI]: 0.51-0.71), and Drug substitutions of efavirenz (EFV) were more likely than of nevirapine (NVP)-containing (AOR 1.82; 95% CI: 1.42-2.33) regimens. Predictors of switch to second-line regimen include older age (AOR 2.05; 95% CI: 1.68-2.51), CD4 count≤100 cells/mm3 (AOR 1.89; 95% CI: 1.49-2.37), EFV compared to NVP (AOR 1.38; 95% CI: 1.02-1.88), and drug toxicity (AOR 1.90; 95% CI: 1.48-2.43).

CONCLUSION

Modification to initial ART was common in this study. Further evaluation of the contribution of guideline changes on regimen modification and treatment outcomes is recommended.

HIV-associated lipodystrophy: a review from a Brazilian perspective

The prognosis of human immunodeficiency virus (HIV)-infected individuals has dramatically improved worldwide since the introduction of highly antiretroviral therapy. Nevertheless, along with the decrease in mortality, several body modifications not initially related to HIV infection have been reported. Disorders in lipid and glucose metabolism, accompanied by body shape abnormalities and alterations in fat distribution, began to be described. A syndrome, named "HIV-associated lipodystrophy syndrome", was coined to classify these clinical spectrum aspects. This syndrome involves not only metabolic alterations but also fat redistribution, with lipoatrophy due to subcutaneous fat loss (predominantly in the face and lower limbs) and lipohypertrophy related to central fat gain. These changes in body shape are very important to be recognized, as they are associated with worse morbidity and mortality. Self-esteem difficulties related to body alterations might lead to treatment failures due to medication adherence problems. Moreover, these alterations have been associated with an increased risk of cardiovascular events. Therefore, it is extremely important to identify this syndrome early in order to provide an even better quality of life for this population, as the clinical approach is not easy. Treatment change, medications to treat dyslipidemia, and surgical intervention are instruments to be used to try to correct these abnormalities. The aim of this study is to review clinical presentation, diagnosis, and management of body shape and metabolic complications of HIV infection from a Brazilian perspective, a medium income country with a large number of patients on antiretroviral therapy.

Treatment-limiting toxicities associated withnucleoside analogue reverse transcriptase inhibitor therapy: A prospective, observational study

BACKGROUND

The Recover Study is an ongoing, prospective study designed 10 to assess toxicity associated with the use of nucleoside analogue reverse transcriptase inhibitors (NRTIs) (stavudine, zidovudine, lamivudine, didanosine, abacavir) in HIV-1-infected patients receiving highly active antiretroviral therapy (HAART) in routine clinical practice. This project is being conducted at 120 HIV units at teaching hospitals across Spain.

OBJECTIVE

The aim of this study was to identify the most common treatment-limiting 10 moderate to severe clinical and laboratory adverse effects (AEs), and the individual NRTIs involved in the development of these effects, in HIV-1-infected patients receiving HAART who discontinued use of an NRTI in the Recover Study.

METHODS

Patients eligible for participation in the Recover Study are aged10 ≥18 years; have virologically documented HIV-1 infection; have sustained viral suppression (viral load <200 cells/mL or stable, heavily experienced [ie, have received ≥3 antiretroviral regimens] patients with viral load <5000 cells/mL) for ≥6 months; are receiving HAART; are undergoing active follow-up; and have developed 2:1 NRTI-associated AE that, in the opinion of a study investigator and under the conditions of routine clinical practice, justified discontinuation of treatment with the offending drug (principal AE/offending NRTI). The present study included patients recruited for the Recover Study between September 2002 and May 2003.

RESULTS

A total of 1391 patients were enrolled (966 men, 425 women; mean 1 age, 42 years [range, 18-67 years]). Five hundred six patients (36.4%) had been diagnosed with AIDS. The mean duration of treatment with the offending NRTI was 74 months (range, 6-156 months). Seven hundred nine patients (51.0%) were receiving fourth-line (or more) therapy. Eight hundred twenty-one patients (59.0%) were receiving nonnucleoside analogues, and 552 patients (39.7%), protease inhibitors, as components of their HAART regimens. The NRTIs with the highest discontinuation rates were stavudine (914 patients [65.7%]) and zidovudine (177 [12.7%]). The most frequent NRTI-related AEs were lipoatrophy (550 patients [39.5%]) and peripheral neuropathy (170 [12.2%]). Lipoatrophy was most commonly associated with stavudine (480/550 cases [87.3%]); periph eral neuropathy, with stavudine and didanosine (107/170 [62.9%] and 48/170 [28.2%] cases, respectively); and anemia, with zidovudine (70/77 cases [90.9%]).

CONCLUSIONS

The results of this study in patients with HIV-1 recruited in the10 Recover Study and undergoing HAART suggest that long-term treatment with NRTIs is associated with AEs (lipoatrophy, peripheral neuropathy, and lipodystrophy), with morphologic disorders (lipoatrophy, lipodystrophy) being the most common AEs leading to discontinuation. Minimizing these AEs by switching to an NRTI not associated with these AEs (eg, tenofovir) would contribute to adherence and hence efficacy of long-term HAART.

Endocrine and metabolic abnormalities among HIV-infected patients: A current review

Multiple endocrine and metabolic abnormalities have been reported among human immunodeficiency virus (HIV) patients since the pre-antiretroviral therapy era. These abnormalities present with either subclinical or overt clinical features. Endocrine and metabolic abnormalities primarily occur due to the direct destructive effects of HIV, malignancies and opportunistic infections on the varied endocrine glands and antiretroviral therapy-associated toxicities. This article offers a broad review on the commonly encountered endocrine and metabolic abnormalities among HIV-infected patients. Timely endocrine or metabolic evaluations should be performed among patients suspected with endocrine or metabolic dysfunction and appropriate treatment instituted since the majority of these conditions pose an increased risk of mortality if undiagnosed or untreated.

Pathophysiology of GHRH-growth hormone-IGF1 axis in HIV/AIDS

Aberrations in GHRH-GH -IGF-I axis are common in the complex of HIV, HAART and AIDS. There are 2 distinct mechanisms at play in HIV and AIDS. One is primarly associated with development of lipodystrophy and results in complications such as chronic inflammation, insulin resistance, lipid and metabolic abnormalities. HIV lipodystrophy is found especially in those on highly active anti-retroviral therapy (HAART). The various processes involved in lipodystrophy result in the suppression of pituitary GH production. The mechanism of low GH levels relates to increased somatostatin tone, decreased Ghrelin, increased free fatty acids (FFA) and insulin resistance. On the other hand in AIDS wasting syndrome; elevated GH and low IGF-1 levels are seen suggesting GH resistance. The GHRH analog-Tesamorelin is the only treatment option, which is FDA approved for use in reduction of excess abdominal fat in patients with HIV-associated lipodystrophy. Although long-term clinical trials and experience is needed to further study the benefits and risks of Tesamorelin.

Pathophysiology of the HIV-Associated Lipodystrophy Syndrome

The widespread use of highly active antiretroviral therapy (HAART) has radically transformed the prognosis of HIV-infected patients in the developed countries. Unfortunately, a serious metabolic syndrome combining peripheral lipoatrohy, central adiposity, insulin resistance, and dyslipidemia has arisen in these individuals. The etiology of this heterogeneous syndrome named lipodystrophy syndrome (LDS) is multifactorial, but adipose tissue is very likely a key factor that contributes to several clinical or metabolic aspects of the syndrome. In peripheral adipose tissue, HAART may act on both preadipocytes and adipocytes to induce fat loss. Several components of the HAART regimen can inhibit preadipocyte differentiation, in particular through alterations in the expression and/or function of the transcription factor sterol responsive element binding protein-1c. In superficial mature adipocytes, HAART promotes insulin resistance and apoptosis. Insulin resistance of peripheral fat cells could be the consequence of increased lipolysis and adipocytokine dysregulation. In turn, the increased free fatty acid disposal and the disturbances in adipocytokine production may induce skeletal muscle and liver insulin resistance, dyslipidemia, and a fat redistribution toward deep depots, causing visceral lipohypertrophy. The metabolic profile observed in LDS is reminiscent of that observed in metabolic syndrome, raising potential implications for cardiovascular risk in these patients. The pathophysiological mechanisms at the basis of this syndrome represent a rational basis for the treatment or prevention of the metabolic complications.

Effectiveness and safety of 30 mg versus 40 mg stavudine regimens: a cohort study among HIV-infected adults initiating HAART in South Africa

BACKGROUND

As stavudine remains an important and widely prescribed drug in resource-limited settings, the effect of a reduced dose of stavudine (from 40 mg to 30 mg) on outcomes of highly active antiretroviral therapy (HAART) remains an important public health question.

METHODS

We analyzed prospectively collected data from the Themba Lethu Clinic in Johannesburg, South Africa. We assessed the relationship between stavudine dose and six- and/or 12-month outcomes of stavudine substitution, failure to suppress viral load to below 400 copies/ml, development of peripheral neuropathy, lipoatrophy and hyperlactatemia/lactic acidosis. Since individuals with a baseline weight of less than 60 kg were expected to have received the same dose of stavudine throughout the study period, analysis was restricted to individuals who weighed 60 kg or more at baseline. Data were analyzed using logistic regression.

RESULTS

Between 1 April 2004 and 30 September 2009, 3910 patients were initiated on antiretroviral therapy (ART) with a recorded stavudine dose and were included in the analysis. Of these, 2445 (62.5%) received a 40 mg stavudine dose while 1565 (37.5%) received 30 mg. In multivariate analysis, patients receiving a 40 mg dose were more likely to discontinue stavudine use (adjusted odds ratio, OR 1.71; 95% confidence limits, CI 1.13-2.57) than those receiving 30 mg by 12 months on ART. Additionally, patients receiving 40 mg doses of stavudine were more likely to report peripheral neuropathy (OR 3.12; 95% CI 1.86-5.25), lipoatrophy (OR 11.8; 95% CI 3.2-43.8) and hyperlactatemia/lactic acidosis (OR 8.37; 95% CI 3.83-18.29) in the same time period. Failure to suppress HIV viral load within 12 months of HAART initiation was somewhat more common among those given 40 mg doses (OR 1.62; 95% CI 0.88, 2.97) although this result lacked precision. Sensitivity analyses accounting for death and loss to follow up generally supported these estimates.

CONCLUSIONS

Lower stavudine dosage is associated with fewer reports of several stavudine-associated adverse events and also a lower risk of stavudine discontinuation within the first year on ART.

Factors associated with insulin resistance among children and adolescents perinatally infected with HIV-1 in the pediatric HIV/AIDS cohort study

BACKGROUND/AIMS

Because of prior inconsistent findings, we studied a large cohort of HIV-infected children to determine: (1) prevalence of insulin resistance (IR); (2) anthropometric and clinical correlates of IR, and (3) concomitant abnormalities of glucose tolerance.

METHODS

The study population consisted of 451 children from the Pediatric HIV/AIDS Cohort Study. The outcome of interest was HOMA-IR. Covariates included demographic, metabolic, growth, body composition, HIV laboratory tests, and treatment characteristics. Children meeting triggers for IR underwent oral glucose tolerance tests and hemoglobin A1c (HbA1c) measurements.

RESULTS

Among 402 children with glucose and insulin measurements, 15.2% had IR of whom 79% were pubertal. IR was associated with higher alanine aminotransferase, body mass index, and nadir CD4%, Tanner stage 5, and ever having received amprenavir. Of those with IR, three had impaired fasting glucose (IFG), three impaired glucose tolerance (IGT), one IFG and IGT, none diabetic glucose tolerance, and three HbA1c between 6.1 and 6.5%.

CONCLUSION

In our cohort of HIV-infected adolescents, we observed a 15.2% prevalence of IR more closely linked to obesity than any other variable. This finding mirrors the high prevalence of obesity-mediated IR in American youth. However, associations with CD4 count and use of protease inhibitors may indicate some effect of HIV and/or its treatment.

Management of the metabolic effects of HIV and HIV drugs

Morphologic and metabolic abnormalities, including subcutaneous adipose tissue wasting, central adipose tissue accumulation, dyslipidemia and disorders of glucose metabolism are common among HIV-infected patients receiving highly active antiretroviral therapy (HAART) and contribute to the risk of cardiovascular disease in this population. The pathogenesis of these disorders is due to complicated interactions between effects of chronic HIV infection, HAART medications and patient factors, including genetic susceptibility. HAART has transformed HIV into a chronic condition for many patients and as a result the majority of HIV-infected patients in many areas of the developed world will soon be aged ≥50 years. Given that metabolic and cardiovascular diseases increase with aging, knowledge of the optimal management of these conditions is essential for practitioners caring for HIV-infected patients, including endocrine subspecialists. This Review highlights the clinical management of these disorders, focusing on the latest evidence regarding the efficacy of treatment strategies, newly available medications and potential interactions between HAART medications and medications used to treat metabolic disorders.

The Relationship Between HIV Infection and Cardiovascular Disease

Over 30 million people are currently living with human immunodeficiency virus (HIV) infection, and over 2 million new infections occur per year. HIV has been found to directly affect vascular biology resulting in an increased risk of cardiovascular disease compared to uninfected persons. Although HIV infection can now be treated effectively with combination antiretroviral medications, significant toxicities such as hyperlipidemia, diabetes, and excess cardiovascular co-morbidity; as well as the potential for significant drug-drug interactions between HIV and cardiovascular medications, present new challenges for the management of persons infected with HIV. We first review basic principles of HIV pathogenesis and treatment and then discuss relevant clinical management strategies that will be useful for cardiologists who might be involved in the care of HIV infected patients.

Disorders of fat partitioning in treated HIV-infection

HIV-associated lipodystrophy is clinically characterized by body fat changes including subcutaneous fat loss (lipoatrophy) with or without truncal fat accumulation (lipohypertrophy). Thymidine nucleoside reverse transcriptase inhibitors, stavudine and to a lesser extent zidovudine, are major contributors for lipoatrophy. Drug factors are not clear for lipohypertrophy. Restoration to health with effective viral suppression and weight gain may be factors playing significant roles in lipohypertrophy. Mitochondrial dysfunction and inflammation in subcutaneous adipose tissue are key factors in the pathogenesis of HIV-associated lipoatrophy. The pathogenesis of lipohypertrophy is less well understood. Switching from thymidine nucleoside reverse transcriptase inhibitors restores subcutaneous fat in patients with HIV-associated lipoatrophy, but improvement is slow and limited. Surgical filling cosmetically improves facial lipoatrophy. Exercise and diet may reduce increased visceral adipose tissue. Liposuction may be useful to remove superficial, localized fat accumuli.

Pathogenesis and treatment of HIV lipohypertrophy

PURPOSE OF REVIEW

This review addresses our current understanding of the pathogenesis of HIV-associated lipohypertrophy and describes an evidence-based approach to treatment.

RECENT FINDINGS

Although the pathogenesis of HIV-associated lipohypertrophy remains elusive, recent clinical and laboratory investigations in fatty acid metabolism and growth hormone dynamics have furthered our understanding of the condition. These findings have also paved the way for new therapeutic interventions, of which tesamorelin, an analog of growth hormone-releasing hormone (GHRH), has gained recognition as a promising treatment strategy against visceral fat accumulation. Recent randomized placebo-controlled trials of tesamorelin demonstrated significant reductions in visceral adipose tissue, improvement in lipid parameters, and minimal adverse effects on glucose tolerance. Optimal therapeutic dosing and treatment duration, though, are not yet known. Whether treatment with GHRH-analogs will translate into improved long-term metabolic and cardiovascular outcomes also remains to be seen.

SUMMARY

Although the pathogenesis of HIV lipohypertrophy remains unclear, several theories and observations have led to the development of treatment strategies to counter fat accumulation and its accompanying metabolic complications. Based on clinical trials, analogs of the growth hormone (GH)/GHRH axis appear to be most effective in reducing visceral adipose tissue.

The efficacy and safety of insulin-sensitizing drugs in HIV-associated lipodystrophy syndrome: a meta-analysis of randomized trials

Background

HIV-associated lipodystrophy syndrome (HALS) is characterized by insulin resistance, abnormal lipid metabolism and redistribution of body fat. To date, there has been no quantitative summary of the effects of insulin sensitizing-agents for the treatment of this challenging problem.

Methods

We searched MEDLINE, the Cochrane Library, clinical trial registries, conference proceedings and references for randomized trials evaluating rosiglitazone, pioglitazone or metformin in patients with evidence of HALS (last update December 2009). Two reviewers independently abstracted data and assessed quality using a standard form. We contacted authors for missing data and calculated weighted mean differences (WMD) and 95% confidence intervals (CI) for each outcome.

Results

Sixteen trials involving 920 patients met inclusion criteria. Rosiglitazone modestly improved fasting insulin (WMD -3.67 mU/L; CI -7.03, -0.31) but worsened triglycerides (WMD 32.5 mg/dL; CI 1.93, 63.1), LDL (WMD 11.33 mg/dL; CI 1.85, 20.82) and HDL (WMD -2.91 mg/dL; CI -4.56, -1.26) when compared to placebo or no treatment in seven trials. Conversely, pioglitazone had no impact on fasting insulin, triglycerides or LDL but improved HDL (WMD 7.60 mg/dL; CI 0.20, 15.0) when compared to placebo in two trials. Neither drug favorably impacted measures of fat redistribution. Based on six trials with placebo or no treatment controls, metformin reduced fasting insulin (WMD -8.94 mU/L; CI -13.0, -4.90), triglycerides (WMD -42.87 mg/dL; CI -73.3, -12.5), body mass index (WMD -0.70 kg/m²; CI -1.09, -0.31) and waist-to-hip ratio (WMD -0.02; CI -0.03, 0.00). Three trials directly compared metformin to rosiglitazone. While effects on insulin were comparable, lipid levels and measures of fat redistribution all favored metformin. Severe adverse events were uncommon in all 16 trials.

Conclusion

Based on our meta-analysis, rosiglitazone should not be used in HALS. While pioglitazone may be safer, any benefits appear small. Metformin was the only insulin-sensitizer to demonstrate beneficial effects on all three components of HALS.

Efficacy and safety of atazanavir-ritonavir plus abacavir-lamivudine or tenofovir-emtricitabine in patients with hyperlipidaemia switched from a stable protease inhibitor-based regimen including one thymidine analogue

Randomized, open-label, prospective clinical trial assessing efficacy and safety on hyperlipidemia of a switching from a regimen including one protease inhibitor and one thymidine analogue to atazanavir/ritonavir plus abacavir/lamivudine or tenofovir/emtricitabine. Adult HIV-infected patients on their first antiretroviral therapy (of at least 48-week duration), including one protease inhibitor and zidovudine or stavudine, with stable immunovirologic features, and having diagnosis of persisting hyperlipidemia, were randomized to replace current treatment with atazanavir/ritonavir plus abacavir/lamivudine (arm A) or tenofovir/emtricitabine (arm B), and were followed for 48 weeks. Eighty-nine patients were enrolled: 42 patients were randomized to arm A, and 47 to arm B. At the end of the 48-week follow-up, incidence of virologic failure was comparable in both arms, and associated with a poor drug compliance. Increase in CD4 lymphocyte count was significantly higher in arm A after a 24-week study period (62.5 versus 39.2 x 10(6) cells/L; p < 0.05), while immunologic responses were comparable at the end of 48-week follow-up (91.5 versus 83.6; p > 0.05). A statistically significant reduction (-15.4%) in mean triglyceridaemia versus respective baseline values was reported in both groups (p < 0.05), without statistically significant difference between arm A and B. Similar results were reported for total cholesterol and low-density lipoprotein (LDL) cholesterol levels. Safety and tolerability profiles were comparable in both groups. Switching from a protease inhibitor- and thymidine analogue-based antiretroviral regimen to atazanavir/ritonavir plus abacavir/lamivudine or tenofovir/emtricitabine proved effective in the management of hyperlipidemia, without significant differences in lipid-lowering effect, virologic efficacy, and safety profile between these regimens.

The effect of individual antiretroviral drugs on body composition in HIV-infected persons initiating highly active antiretroviral therapy

OBJECTIVE

To examine the long-term effects of individual antiretroviral drugs on body composition among 416 persons initiating antiretroviral therapy (ART).

METHODS

In a substudy of a clinical trial of persons initiating ART, changes in body composition attributable to individual ART were examined. ARTs assessed were as follows: indinavir, ritonavir, nelfinavir, efavirenz, nevirapine, stavudine (d4T), zidovudine (ZDV), lamivudine (3TC), didanosine, and abacavir. Skinfolds and circumferences were measured at baseline and every 4 months. Mid arm, mid thigh, and waist subcutaneous tissue areas and nonsubcutaneous tissue areas were calculated. Rates of change per year of exposure to each individual ART drug were determined using multivariate longitudinal regression.

RESULTS

d4T and ZDV use was associated with losses in subcutaneous tissue area and skinfold thickness. 3TC use was associated with gains in all subcutaneous tissue areas and skinfold thickness, whereas abacavir use was associated with an increase in waist subcutaneous tissue area. Indinavir was associated with gains in waist subcutaneous tissue area, whereas indinavir, efavirenz, and nevirapine were associated with increases in upper back skinfolds. d4T use was also associated with increases in all nonsubcutaneous tissue areas; 3TC use was associated with the greatest increase in waist nonsubcutaneous tissue area.

CONCLUSION

In this prospective nonrandomized evaluation, the nucleoside reverse transcriptase inhibitors d4T and ZDV were associated with decreases in subcutaneous tissue areas, whereas 3TC use was associated with increased subcutaneous tissue areas and waist nonsubcutaneous tissue area.

Treatment options for HIV-associated central fat accumulation

Central fat accumulation is increasingly recognized as a problem for patients with HIV infection. The term "lipodystrophy" has been used to describe collectively a constellation of body habitus changes and metabolic abnormalities commonly observed in HIV-infected patients, particularly since the advent of highly active antiretroviral therapy. Visceral fat accumulation can place patients at increased risk of coronary artery disease.Furthermore, body shape changes are a source of distress to patients that may compromise treatment adherence.Reduction of abdominal obesity can therefore be considered part of therapy in HIV-positive patients with visceral adipose tissue (VAT) accumulation. Currently, there are no drugs approved by the Food and Drug Administration for the treatment of HIV-associated central fat accumulation. Lifestyle modifications such as diet and exercise and switching antiretroviral therapies appear to be of limited value in reducing VAT. Metformin has shown some benefit in reducing VAT but at the expense of accelerating peripheral fat loss, and the thiazolidinediones have no effect on VAT. Similarly, testosterone does not appear to reduce VAT in these patients,and there are no data on anabolic steroids. Two large, randomized controlled trials have demonstrated the efficacy of recombinant human growth hormone (rhGH) in reducing visceral adipose tissue. There are also promising data regarding treatment with growth hormone releasing hormone (GHRH).

Hepatic histopathology and clinical characteristics associated with antiretroviral therapy in HIV patients without viral hepatitis

BACKGROUND

All available ARV (antiretroviral) agents can cause hepatotoxicity. Many case reports of ARV-induced hepatotoxicity have been described in patients with confounding viral hepatitis. This case series is comprised 23 HIV-positive patients with hepatic enzyme abnormalities but without the evidence of viral hepatitis. The data available for these 23 patients were assessed with an effort to establish any correlation between ARV therapy and abnormal liver function tests (LFTs) as well as the histologic findings on liver biopsies.

METHODS

The 23 participants included in this study were referred to a hepatology/gastrointestinal clinic that catered specifically to HIV patients. The patients were referred by their HIV providers for evaluation of elevated LFTs, gastrointestinal symptoms or cirrhosis. The data surveyed included variables associated with hepatotoxicity and HIV infection.

RESULTS

Liver biopsies were obtained in 21 out of 23 participants. The remaining two participants had evidence of cirrhosis based on imaging studies. The LFT elevations were definitely or possibly attributed to ARV therapy in 17 out of 23 participants. Specifically, the biochemical hepatotoxicity was definitely related to ARV therapy in six and possibly related to ARV medications in 11 participants. Nine out of 17 participants had evidence of nonalcoholic steatohepatitis, whereas four out of 17 had clinical features of lipodystrophy. Six participants had elevated LFTs before starting ARV therapy. The participants with nonalcoholic fatty liver diseases had normal LFTs for many years after which a steep rise was noted. All participants with nonalcoholic fatty liver diseases were exposed to nucleoside reverse transcriptase inhibitors.

CONCLUSION

ARV medications, particularly the nucleoside reverse transcriptase inhibitors, can cause a dose-dependent hepatotoxicity that occurs after several months of exposure and possibly result in increasing the adverse effects of alcohol and obesity. Owing to the overlap of ARV medications, the contribution of each class of drugs toward the observed hepatotoxicity is not entirely clear. Liver biopsies should be considered in patients receiving ARV therapy with elevated LFTs and/or evidence of fatty liver.

Hormonal contraception and HIV-positive women: metabolic concerns and management strategies

As HIV-positive women live longer lives, and as testing for HIV becomes more routine, clinicians can expect to see more HIV-positive women in their practices. The need to be aware of management issues particular to this population becomes increasingly important. Metabolic dysregulation is a common, long-term complication associated with HIV and is one of the most difficult to manage. Hormonal contraception also is associated with metabolic dysregulation. As more HIV-positive women choose long-term, reversible contraception, the potential for concomitant and additive side effects, and the need for careful, proactive management strategies to avoid these complications, will become more important. This article reviews research detailing the metabolic dysfunction associated with hormonal contraception and with HIV-seropositivity. It highlights reasons for concern regarding the potential, although as yet theoretical, increased risk for metabolic dysfunction when hormonal contraception is used in the presence of HIV. Suggestions for management strategies for women living with HIV who choose to use hormonal contraception are presented. These strategies should be viewed as suggestions for management until substantitive research becomes available.

Insulin resistance and diabetes mellitus associated with antiretroviral use in HIV-infected patients: pathogenesis, prevention, and treatment options

The contribution of current antiretroviral treatment regimens to the long-term survival of HIV-infected individuals is accompanied by increased risk of glucose metabolism abnormalities in this patient population. The risk of insulin resistance and diabetes in HIV-infected patients receiving antiretroviral treatment stems from 2 sources: exposure to the same environmental factors that have led to an increased incidence of these conditions in the general population and the negative effects on glucose metabolism inherent to components of antiretroviral treatment regimens. This article reviews the pathogenesis and diagnosis of insulin resistance and diabetes and the contribution of components of antiretroviral therapy regimens to increased risk for these conditions. Optimization of antiretroviral treatment regimens for HIV-infected patients with or at increased risk for development of abnormalities in glucose metabolism is discussed.

Approach to the human immunodeficiency virus-infected patient with lipodystrophy

Subcutaneous atrophy and central fat accumulation are common among HIV-infected patients receiving highly active antiretroviral therapy, and may be accompanied by dyslipidemia and insulin resistance. These fat changes, although commonly referred to together as lipodystrophy, are best considered as separate disorders, with distinct pathogeneses and treatment approaches. These morphological and metabolic abnormalities first appeared after introduction of protease inhibitors more than 10 yr ago, but research has demonstrated that their pathogenesis is multifactorial, with contributions from other antiretroviral medications, patient-related factors, and HIV itself. Switching to a less toxic highly active antiretroviral therapy regimen has shown partial effectiveness for the management of fat atrophy and lipid abnormalities. Lifestyle modification or surgical approaches are the treatment of choice for lipohypertrophy, although novel therapies targeting the GH axis show promise. HIV-related dyslipidemia may be difficult to treat, and can be complicated by drug-drug interactions between some lipid-lowering medications and antiretroviral medications. Treatment of diabetes in HIV-infected patients should generally follow established guidelines, but thiazolidinediones, rather than metformin, may be considered first-line treatment in a patient with lipoatrophy, given their potential to increase sc fat. The contribution of body fat changes and metabolic abnormalities to cardiovascular risk and the changing risk profiles of newer antiretroviral regimens are under intense investigation.

Interventions for body habitus changes associated with HIV infection and its treatment

Lipodystrophy and its two components lipo-accumulation and lipoatropy are very common among individuals with HIV infection on treatment, especially among those who started therapy in the late 1990s and early 2000s. This review discusses the current management of these complications of HIV and its treatment. For the purpose of clarity in this review, we have divided the interventions according to the predominant phenotype of the individual.

Management of antiretroviral treatment-related complications

Antiretroviral therapy for HIV restores immune function, controls viral replication, decreases opportunistic infections, and extends lifespan to near-normal for infected individuals. However, successful HIV therapy has been accompanied by the emergence of treatment-related complications, with an impact not yet fully understood. This article reviews six common complications of antiretroviral therapy, including hyperlactatemia/lactic acidosis, hypersensitivity reactions, abnormal glucose metabolism, dyslipidemia, body composition changes, and cardiovascular disease. A comprehensive approach to management of antiretroviral-related complications includes awareness of (1) risk factors for adverse reactions, (2) clinical syndromes suggestive of an evolving complication, and (3) evidence-based monitoring and treatment strategies. Fluency in options for preventing and managing complications can provide maximal opportunity to balance treatment effects with quality of life.

Longitudinal increases in waist circumference are associated with HIV-serostatus, independent of antiretroviral therapy

BACKGROUND

The relative contributions of the different classes of antiretroviral therapy (ART), HIV infection per se, and aging to body shape changes in HIV-infected patients have not been clearly defined in longitudinal studies.

METHODS

Since September 1999, men enrolled in the Multicenter AIDS Cohort Study have undergone measurements of body mass index (BMI) and body circumferences at each semi-annual visit. The effect of HIV-serostatus and cumulative exposure to the three major ART classes on changes in anthropomorphic measurements occurring between 1999 and 2004 among HIV-infected and HIV-uninfected men were determined using linear mixed effects regression models.

RESULTS

At baseline, average BMI and circumference measurements were greater in HIV-uninfected men (n = 392) than HIV-infected men (n = 661) (BMI, 27.3 versus 25.3 kg/m; waist, 96.4 versus 90.2 cm; hip 101.3 versus 95 cm, thigh 54.1 versus 50.8 cm; arm 33.3 versus 31.7 cm, P < 0.001 for each comparison). Cumulative nucleoside reverse transcriptase inhibitor (NRTI) exposure, but not protease inhibitor or non-nucleoside reverse transcriptase inhibitor exposure, was associated with statistically significant changes in BMI (-0.11 +/- 0.04 kg/m per year) and in circumferences of waist (-0.27 +/- 0.07 cm/year), hip (-0.24 +/- 0.05 cm/year), and thigh (-0.16 +/- 0.03 cm/year) over the 5 years of follow-up. Independent of ART exposure, HIV-infected men had a more rapid increase in waist circumference over the study interval than did the HIV-uninfected men (difference 0.33 +/- 0.15 cm/year, P = 0.02).

CONCLUSION

Cumulative NRTI therapy was associated with longitudinal decreases in body circumference measurements, whereas HIV-serostatus was associated with increases in waist circumference independent of ART.

Switching to a protease inhibitor-containing, nucleoside-sparing regimen (lopinavir/ritonavir plus efavirenz) increases limb fat but raises serum lipid levels: results of a prospective randomized trial (AIDS clinical trial group 5125s)

BACKGROUND

Subcutaneous limb fat loss continues to be one the most troubling side effects of long-term antiretroviral regimens. Nucleoside analogues and protease inhibitors (PIs) have been linked to the development of this complication.

METHODS

We evaluated the effects of nucleoside-sparing and PI-sparing regimens on fat distribution, bone mineral density, and metabolic parameters in 62 subjects, who were not selected for lipoatrophy, with advanced HIV (nadir CD4 count <or=200 cells/mm or HIV RNA level >or=80,000 copies/mL) and an undetectable HIV viral load. Participants were randomized to switch their initial successful antiretroviral regimen to open-label lopinavir/ritonavir (LPV/r) at a dose of 533/133 mg twice a day and efavirenz (EFV) at a dose of 600 mg/d (the nucleoside-sparing arm) versus EFV and 2 nucleoside analogues (the PI-sparing arm).

FINDINGS

At week 48, the median change in limb fat in the nucleoside-sparing arm was 562 g (6%, interquartile range [IQR]: -218-1186 g) versus a loss of -242 g (-4%, IQR: -539-452 g) in the nucleoside-containing PI-sparing arm (P = 0.086). At the time of last observation (median = 102 weeks, IQR: 73-152 weeks), a median gain of 782 g (10%, IQR: -380-1168 g) of limb fat was noted in the nonnucleoside arm (n = 22) versus a loss of 850 g (-15%, IQR: -1270 to -526 g) in the nucleoside-containing arm (n = 25; P = 0.002).

INTERPRETATION

The switch to a nucleoside-sparing combination antiretroviral regimen (LPV/r + EFV) was associated with significant improvement in limb fat. These results provide additional evidence that nucleoside analogues are important in the progressive limb fat loss that characterizes antiretroviral treatment and that switching medications can significantly improve this complication. This option has to be carefully balanced with the potential to increase serum lipid levels and the trend to increase virologic failure.

Insulin resistance, glucose intolerance and diabetes mellitus in HIV-infected patients

An increased prevalence of insulin resistance, glucose intolerance and diabetes has been reported in HIV infection in the highly active antiretroviral therapy (HAART) era. This development might be clinically significant because of its association with cardiovascular morbidity and mortality as well as the therapeutic challenges of managing polypharmacy. The development of insulin resistance, glucose intolerance and diabetes could be related to the underlying HIV infection, the contribution of different antiretroviral agents, treatment-associated weight gain, immune restoration, as well as the non-HIV related factors. Dissecting these factors in clinical practice might be difficult. Clinical studies include short-term treatments in healthy, non-HIV-infected individuals; randomized, controlled trials; comparative studies of different HAART regimens; and randomized studies of switching regimens in patients with viral suppression and stable immune function. This article reviews the latest knowledge regarding the epidemiology, pathogenesis, prevention and treatment of insulin resistance, glucose intolerance and diabetes mellitus in HIV-infected individuals.

Long-term complications of antiretroviral therapy: lipoatrophy

The effective use of potent antiretroviral therapy has dramatically improved the life expectancy for HIV-infected individuals. Long-term complications of both HIV-infection and antiretroviral agents are therefore of increasing concern. Lipoatrophy (LA) or fat wasting is a complication most frequently associated with nucleoside reverse transcriptase inhibitors, thymidine analogues particularly. LA can be stigmatising and is associated with psychosocial complication. It can occur in isolation or as part of the 'metabolic' or 'lipodystrophy' syndrome, a triad of LA, fat accumulation and metabolic disturbance (insulin resistance and dyslipidaemia) with a subsequently increased risk of cardiovascular events. We aimed to review the definition, prevalence, pathogenesis, implications and treatment of HIV/highly active antiretroviral therapy-associated fat loss. We performed a review of PubMed, Medline and recent conference abstracts for information on LA. The current treatments available for treating LA are limited. Switching away from thymidine analogues can provide a small benefit but improvement is, at best, slow and partial. Specific medical therapies such as glitazones, metformin and stating have been disappointing to date. Surgical fillers can yield marked results but are costly, time consuming and only of value for facial LA, not other sites. Ultimately, prevention of this condition is the best approach by avoiding thymidine analogues wherever possible or careful monitoring with early switching away from these agents. New therapies to treat pre-existing fat loss are required.

Management of antiretroviral drug toxicity

PURPOSE OF REVIEW

With the emergence of very potent antiretroviral regimens, the major limitation to the success of treatment is now the tolerability of drugs, which can ultimately affect adherence. It is important, therefore, to review the current understanding on antiretroviral drug toxicity, and examine key recent data that can inform the successful avoidance or management of such toxicities.

RECENT FINDINGS

A common theme of recent research has focussed on the genetic predisposition to important immediate side-effects, such as abacavir hypersensitivity, nevirapine hepatotoxicity, efavirenz neurotoxicity and hyperbilirubinemia with atazanavir. Long-term toxicities such as body-composition changes and hyperlipidemia have been more closely linked to thymidine analogues and certain protease inhibitors. The management of these toxicities has also been clarified by studies addressing switching antiretroviral drugs or specific treatments for metabolic syndromes.

SUMMARY

Recent data emphasize the need for the prevention of antiretroviral toxicity by the avoidance of some drugs in certain genetically predisposed populations or by the avoidance of entire classes if possible. In addition, recent studies emphasize the importance of ongoing research to determine the emergence of additional toxicities, as new drugs emerge and achieve widespread use.

Current concepts in the diagnosis and management of metabolic complications of HIV infection and its therapy

Changes in fat distribution, dyslipidemia, disordered glucose metabolism, and lactic acidosis have emerged as significant challenges to the treatment of human immunodeficiency virus (HIV) infection. Over the past decade, numerous investigations have been conducted to better define these conditions, identify risk factors associated with their development, and test potential therapeutic interventions. The lack of standardized diagnostic criteria, as well as disparate study populations and research methods, have led to conflicting data regarding the diagnosis and treatment of metabolic and body shape disorders associated with HIV infection. On the basis of a review of the medical literature published and/or data presented before April 2006, we have prepared a guide to assist the clinician in the detection and management of these complications.

Recomendaciones de GEAM/SPNS sobre el tratamiento de las alteraciones metabólicas y morfológicas en el paciente con infección por VIH

OBJECTIVE

To provide an update of the metabolic and morphologic alterations in patients infected with HIV with an in-depth analysis of their clinical management and treatment.

METHODS

These recommendations were agreed by consensus by a committee of experts in metabolic alterations and HIV patient care, under the auspices of the Secretariat for the National AIDS Plan. To do this, the latest clinical, epidemiological and physiopathological advances described in studies published in the scientific literature and/or presented in congresses were reviewed.

RESULTS

The most frequent metabolic alterations in HIV patients and in antiretroviral treatment (ART) are dyslipidemia with an atherogenic profile and alterations in carbohydrate metabolism/insulin resistance. A high prevalence of cardiovascular risk factors, especially smoking, has been described. The same criteria for their management as those used in the general population have been employed, with specific nuances. Diet and exercise should be the first therapeutic recommendation. In patients with dyslipidemia who require drug treatment, statins and/or fibrates are indicated. Glitazones have demonstrated efficacy in the treatment of insulin resistance. The approach to anomalous fat distribution continues to be controversial. The main approaches at present are a switch of ART, reparative surgery, psychological support and lifestyle changes. Lactic acidosis is an infrequent but highly serious complication, and the first step is withdrawal of ART. In bone metabolism alterations, prevention and early detection are essential, especially in children and perimenopausal women. Sexual dysfunction is a frequent problem in both men and women; because the causes are highly varied, treatment should be individualized.

CONCLUSIONS

The prevalence of metabolic and morphologic alterations has increased since the introduction of highly active antiretroviral treatment (HAART). Knowledge of the various aspects involved in their diagnosis and treatment is essential for the appropriate care of patients with HIV infection.

Antiretroviral-therapy-associated lipoatrophy: current status and future directions

Lipoatrophy is perhaps the most visibly recognisable component of antiretroviral-therapy-associated lipodystrophy due to the rarity of this form of body composition change in the general population. In this respect, it is apparent that lipoatrophy represents a form of drug toxicity specifically involving the subcutaneous fat tissue, resulting in pathological fat loss that preferentially affects the limbs and face. It is now clear that the choice and duration of nucleoside analogue reverse transcriptase inhibitor (NRTI) therapy (stavudine > zidovudine) is the dominant risk factor for clinical lipoatrophy, as well as for the pathological changes to adipose tissue that underlie the clinical syndrome. Host factors have also emerged as important modulators of lipoatrophy severity in patients receiving these NRTI drugs, including age, racial origin, and severity of immune deficiency. On the other hand, the use of selected HIV protease inhibitor drugs is more closely associated with metabolic complications such as dyslipidemia and insulin resistance and has not been convincingly linked to lipoatrophy. This review examines the clinical and pathological manifestations of lipoatrophy, and also presents information regarding the safety profile of alternative NRTI drugs, such as tenofovir and abacavir, that have not been associated with lipoatrophy risk. With increasing knowledge of lipoatrophy pathogenesis, it is likely that moderate and severe forms of this complication can now be considered a preventable complication of HIV treatment. However, it is also important to recognise that there is an ongoing burden of disease in patients who have been affected by lipoatrophy over the past six years, and that therapeutic management of established lipoatrophy will remain a challenge into the future.

Adverse effects of antiretroviral therapy for HIV infection: a review of selected topics

In the current era of HIV treatment, the toxicity profiles of antiretroviral drugs have increasingly emerged as a basis for selecting initial antiretroviral regimens as well as a reason for switching therapy in treatment-experienced patients. In this respect, an intensive research effort involving clinical research as well as basic science research over the past six years, has focused on the cluster of metabolic and body composition abnormalities that have come to be termed the 'lipodystrophy syndrome'. These data have now provided a clear and clinically relevant understanding of the individual profiles of drugs within the nucleoside analogue reverse transcriptase inhibitor , HIV protease inhibitor and non-nucleoside analogue reverse transcriptase inhibitor drug classes, and have provided a rational basis for assessing and monitoring these adverse effects in clinical practice. In this review, current and emerging drug toxicities are considered with an emphasis on lipodystrophy complications.

Toxidermie à la névirapine

BACKGROUND

Several studies have shown a high prevalence of rash induced by nevirapine. However, there is little knowledge about the risk factors associated with nevirapine-induced rash. The aim of this study was to identify risk factors associated with the occurrence of rash during the treatment with nevirapine of HIV-infected patients.

METHODS

A retrospective study was conducted in the dermatology department of Besançon university teaching hospital between November 1998 and September 2001. The study included all HIV-infected patients receiving HAART regimens that included nevirapine. The following data were collected: age, sex, CDC classification of HIV, CD4 and CD8 lymphocyte counts, plasma HIV RNA load, hepatitis B, C and cytomegalovirus serostatus, history of drug allergy, concomitant medication (other antiretroviral drugs, corticosteroids, antihistamines). Univariate analysis was performed using a Chi2 test or Fischer's test and Student's t test. Fischer's test and the Cox proportional hazards model were used in the multivariate analysis.

RESULTS

During the study period, 101 HIV-infected patients (74 men and 27 women; mean age: 41.6 +/- 10.3 years) were treated with HAART regimens including nevirapine. Fourteen developed cutaneous drug-reactions attributable to nevirapine (13.86%). We observed 13 cases of maculopapular exanthema and 1 case of DRESS. In the univariate analysis, female gender (p=0.002), plasma HIV RNA load > 10,000 copies/ml (p=0.05), heterosexual transmission (p=0.002) and abacavir treatment (p=0.05) constituted risk factors associated with rash. In the multivariate analysis, only female gender (p<0.0001) and plasma HIV RNA load > 10,000 copies/ml (p=0.0007) were associated with rash.

DISCUSSION

The results of this study confirm the high frequency of toxidermy associated with nevirapine therapy. The risk factors associated with occurrence of rash due to nevirapine therapy were female gender and plasma RNA > 10,000 copies/ml. Several studies showed absence of any protective effect of antihistamines and corticosteroids in preventing the cutaneous adverse reactions associated with nevirapine. The identification of risk factors closely associated with nevirapine-induced rash could help physicians determine new strategies for safer use of nevirapine in the HAART regimen.