Reductions in Stavudine Dose Might Ameliorate Mitochondrial-Associated Complications Without Compromising Antiviral Activity

Efficacy and Safety of Tenofovir Disoproxil Fumarate Versus Low-Dose Stavudine Over 96 Weeks: A Multicountry Randomized, Noninferiority Trial

BACKGROUND

Reducing doses of antiretroviral drugs, including stavudine (d4T), may lower toxicity, while preserving efficacy. There are substantial concerns about renal and bone toxicities of tenofovir disoproxil fumarate (TDF).

SETTING

HIV-1-infected treatment-naive adults in India, South Africa, and Uganda.

METHODS

A phase-4, 96-week, randomized, double-blind, noninferiority trial compared d4T 20 mg twice daily and TDF, taken in combination with lamivudine (3TC) and efavirenz (EFV). The primary endpoint was the proportion of participants with HIV-1 RNA <50 copies per milliliter at 48 weeks. Adverse events assessments included measures of bone density and body fat. The trial is registered on Clinicaltrials.gov (NCT02670772).

RESULTS

Between 2012 and 2014, 536 participants were recruited per arm. At week 96, trial completion rates were 75.7% with d4T/3TC/EFV (n = 406) and 82.1% with TDF/3TC/EFV (n = 440, P = 0.011). Noncompletion was largely due to virological failure [6.2% (33) with d4T/3TC/EFV versus 5.4% (29) with TDF/3TC/EFV; P = 0.60]. For the primary endpoint, d4T/3TC/EFV was noninferior to TDF/3TC/EFV (79.3%, 425/536 versus 80.8% 433/536; difference = -1.49%, 95% CI: -6.3 to 3.3; P < 0.001). Drug-related adverse event discontinuations were higher with d4T (6.7%, 36), than TDF (1.1%, 6; P < 0.001). Lipodystrophy was more common with d4T (5.6%, 30) than TDF (0.2%, 1; P < 0.001). Creatinine clearance increased in both arms, by 18.1 mL/min in the d4T arm and 14.2 mL/min with TDF (P = 0.03). Hip bone density measures, however, showed greater loss with TDF.

CONCLUSIONS

Low-dose d4T combined with 3TC/EFV demonstrated noninferior virological efficacy compared with TDF/3TC/EFV, but mitochondrial toxicity remained high. Little renal toxicity occurred in either arm. Implications of bone mineral density changes with TDF warrant investigation.

Low dose versus high dose stavudine for treating people with HIV infection

BACKGROUND

Stavudine remains a component of combination antiretroviral therapy (ART) in resource-constrained countries due to its relatively low cost despite the WHO recommendation for its phasing out as a strategy to reduce stavudine associated toxicities. Where stavudine is still in use, it is recommended at a dose lower than the standard dose in order to reduce stavudine related toxicity.

OBJECTIVES

To compare the safety and virologic efficacy of low dose versus high dose stavudine for treating HIV-1 infection.

SEARCH METHODS

The comprehensive search strategy developed by the Cochrane HIV/AIDS Review Group was used to identify randomised controlled trials that compared the use of low dose versus high dose stavudine. The last search was conducted in February 2014 and the searches covered the period 1996 to 2014.

SELECTION CRITERIA

Randomised controlled trials comparing the use of low dose and high dose stavudine as part of ART combination therapy for treating adults.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected eligible trials, assessed methodological quality of the included studies and completed data extraction and analysis.

MAIN RESULTS

The search identified 3952 abstracts which were scanned for relevance. Three trials met the inclusion criteria (Milinkovic 2007; McComsey 2008; Sanchez-Conde 2005). All three trials were conducted in developed countries, participants were ART experienced and all had sustained virologic suppression at baseline. A total of 157 participants were recruited to the trials. Sample sizes ranged from 24 to 92 and more than 79% of participants were male.The studies were at a high risk of selection, performance/detection and selective outcome reporting biases. Some baseline characteristics differed among the groups, including triglyceride levels in two studies and body mass index in one study. In light of variation in the design and follow-up of the study results, no meta-analysis was performed and the results of single studies are presented. There was no significant difference in virologic suppression in the included studies (Milinkovic 2007; McComsey 2008; Sanchez-Conde 2005); Risk Ratio (RR) 1.09 (95% CI: 0.93 to 1.28), 0.94 (95% CI:0.59 to 1.50) and 1.03 (95% CI: 0.90 to 1.18) respectively. Symptomatic hyperlactatemia was seen in the high dose arm of the Milinkovic 2007 study; RR 0.21 (95% CI: 0.01 to 4.66), in no participants in the McComsey 2008 trial and not reported on in the Sanchez-Conde 2005 trial. McComsey 2008 and Milinkovic 2007 demonstrated a reduction in bone mineral density (BMD), reduction in limb fat and an increase in triglycerides in the high dose arms. The studies did not indicate that any participants discontinued treatment due to adverse events.

AUTHORS' CONCLUSIONS

This systematic review identified only three small trials that evaluated virologic efficacy and safety of high dose versus low dose stavudine. All three trials were conducted in developed countries and none reported from developing countries yet stavudine remains a component of ART combination therapy in many developing countries. It was not possible to perform a meta-analysis on these trails. Individual results from the trials were imprecise and have not identified a clear advantage in virologic efficacy or safety between low and high dose stavudine. Furthermore, enrolled participants were treatment experienced with sustained virologic suppression and so existing data cannot be generalized to settings where stavudine is currently used in ART naive patients with high viral loads. Stavudine dose reduction trials in ART naive patients, in developing countries where stavudine is still being used are warranted as the phasing out of stavudine that is recommended by WHO may not be immediately universally feasible.

Estimation of intracellular concentration of stavudine triphosphate in HIV-infected children given a reduced dose of 0.5 milligrams per kilogram twice daily

The antiviral efficacy of stavudine depends on the trough concentration of its intracellular metabolite, stavudine-triphosphate (d4T-TP), while the degree of stavudine's mitochondrial toxicity depends on its peak concentration. Rates of mitochondrial toxicity are high when stavudine is used at the current standard pediatric dose (1 mg/kg twice daily [BID]). Evidence from adult work suggests that half of the original standard adult dose (i.e., 20 mg BID) may be equally effective, with markedly less mitochondrial toxicity. We present a population pharmacokinetic model to predict intracellular d4T-TP concentrations in pediatric HIV-infected patients administered a dose of 0.5 mg/kg BID. Our model predicted that the reduced pediatric dose would result in a trough intracellular d4T-TP concentration above that of the reduced 20-mg adult dose and a peak concentration below that of the 20-mg adult dose. The simulated pediatric intracellular d4T-TP at 0.5 mg/kg BID resulted in median peak and trough values of approximately 23.9 fmol/10(6) cells (95% prediction interval [PI], 14.2 to 41 fmol/10(6) cells) and 14.8 fmol/10(6) cells (95% PI, 7.2 to 31 fmol/10(6) cells), respectively. The peak and trough concentrations resulting from a 20-mg BID adult dose were 28.4 fmol/10(6) cells (95% PI, 17.3 to 45.5 fmol/10(6) cells) and 13 fmol/10(6) cells (95% PI, 6.8 to 28.6 fmol/10(6) cells), respectively. Halving the current standard pediatric dose should therefore not compromise antiviral efficacy, while markedly reducing mitochondrial toxicity.

A 72-week randomized study of the safety and efficacy of a stavudine to zidovudine switch at 24 weeks compared to zidovudine or tenofovir disoproxil fumarate when given with lamivudine and nevirapine

BACKGROUND

Due to superior long-term toxicity profiles, zidovudine (AZT) and tenofovir disoproxil fumarate (TDF) are preferred over stavudine (d4T) for first-line antiretroviral regimens. However, short-term d4T use could be beneficial in avoiding AZT-induced anaemia.

METHODS

We randomized (1:1:1) 150 treatment-naive Thai HIV-infected adults with CD4(+) T-cell count <350 cells/mm(3) to arm 1 (24-week GPO-VIR S30(®) [d4T plus lamivudine (3TC) plus nevirapine (NVP)] followed by 48-week GPO-VIR Z250(®) [AZT plus 3TC plus NVP]), arm 2 (72-week GPO-VIR Z250(®)) or arm 3 (72-week TDF plus emtricitabine [FTC] plus NVP). Haemoglobin (Hb), dual energy x-ray absorptiometry, neuropathic signs, estimated glomerular filtration rate (eGFR), CD4(+) T-cell count, plasma HIV RNA and adherence were assessed.

RESULTS

In an intention-to-treat analysis, mean Hb decreased from baseline to week 24 in arm 2 compared with arm 1 (-0.19 versus 0.68 g/dl; P=0.001) and arm 3 (0.48 g/dl; P=0.010). Neuropathic signs were more common in arm 2 compared with arm 3 (20.4 versus 4.2%; P=0.028) at week 24. There were no differences in changes in peripheral fat and eGFR from baseline to weeks 24 and 72 among arms. CD4(+) T-cell count increased more in arm 1 than arms 2 and 3 from baseline to week 24 (168 versus 117 and 118 cells/mm(3); P=0.01 and 0.02, respectively) but the increase from baseline to week 72 was similar among arms.

CONCLUSIONS

A 24-week d4T lead-in therapy caused less anaemia and greater initial CD4(+) T-cell count increase than initiating treatment with AZT. This strategy could be considered in patients with baseline anaemia or low CD4(+) T-cell count. If confirmed in a larger study, this may guide global recommendations on antiretroviral initiation where AZT is more commonly used than TDF.

High prevalence of lipoatrophy in pre-pubertal South African children on antiretroviral therapy: a cross-sectional study

Abstract

Background

Despite changes in WHO guidelines, stavudine is still used extensively for treatment of pediatric HIV in the developing world. Lipoatrophy in sub-Saharan African children can be stigmatizing and have far-reaching consequences. The severity and extent of lipoatrophy in pre-pubertal children living in sub-Saharan Africa is unknown.

Methods

In this cross-sectional study, children who were 3-12 years old, on antiretroviral therapy and pre-pubertal were recruited from a Family HIV Clinic in South Africa. Lipoatrophy was identified and graded by consensus between two HIV pediatricians using a standardized grading scale. A professional dietician performed formal dietary assessment and anthropometric measurements of trunk and limb fat. Previous antiretroviral exposures were recorded. In a Dual-Energy X-ray Absorbtiometry (DXA) substudy body composition was determined in 42 participants.

Results

Among 100 recruits, the prevalence of visually obvious lipoatrophy was 36% (95% CI: 27%–45%). Anthropometry and DXA measurements corroborated the clinical diagnosis of lipoatrophy: Both confirmed significant, substantial extremity fat loss in children with visually obvious lipoatrophy, when adjusted for age and sex. Adjusted odds ratio for developing lipoatrophy was 1.9 (95% CI: 1.3 - 2.9) for each additional year of accumulated exposure to standard dose stavudine. Cumulative time on standard dose stavudine was significantly associated with reductions in biceps and triceps skin-fold thickness (p=0.008).

Conclusions

The prevalence of visually obvious lipoatrophy in pre-pubertal South African children on antiretroviral therapy is high. The amount of stavudine that children are exposed to needs review. Resources are needed to enable low-and-middle-income countries to provide suitable pediatric-formulated alternatives to stavudine-based pediatric regimens. The standard stavudine dose for children may need to be reduced. Diagnosis of lipoatrophy at an early stage is important to allow timeous antiretroviral switching to arrest progression and avoid stigmatization. Diagnosis using visual grading requires training and experience, and DXA and comprehensive anthropometry are not commonly available. A simple objective screening tool is needed to identify early lipoatrophy in resource-limited settings where specialized skills and equipment are not available.

Effects of a reduced dose of stavudine on the incidence and severity of peripheral neuropathy in HIV-infected adults in South Africa

BACKGROUND

Although recent World Health Organization (WHO) guidelines recommend withdrawing stavudine (d4T) from first-line antiretroviral therapy (ART), it remains commonly used in resource-limited settings. In 2006, WHO recommended decreasing the dose of d4T from 40 mg to 30 mg to mitigate toxicities. We compared the incidence and severity of peripheral neuropathy by d4T dose in a retrospective cohort study.

METHODS

Patients' charts from an ART-naive population at a rural clinic in KwaZulu-Natal, South Africa, were retrospectively reviewed for signs and symptoms of incident peripheral neuropathy and were graded for severity using the DAIDS scale. Patients enrolled prior to the WHO guideline change were included in the study if they were on d4T 40 mg for ≥6 months. After the guideline change all patients were initiated on d4T 30 mg.

RESULTS

A total of 475 patients were analysed, including 235 in the 40 mg cohort (152.7 person-years [py]) and 240 in the 30 mg cohort (244.7 py). Incidence of peripheral neuropathy was 90.4/100 py (95% CI 75.9, 106.8) in the 40 mg cohort versus 40.5/100 py (95% CI 32.9, 49.3) in the 30 mg group (incidence rate ratio 0.45; P<0.0001). There was no difference in proportion of severe peripheral neuropathy cases (grade 3/4) between the cohorts: 8.3% in the 40 mg group and 8.9% in the 30 mg group (P=1.0). In a multivariate analysis, risk of peripheral neuropathy was associated with increasing age (hazard ratio [HR] 1.65, 95% CI 1.24, 2.19), 40 mg dose (HR 2.1, 95% CI 1.61, 2.74) and concurrent tuberculosis therapy (HR 1.41, 95% CI 1.06, 1.87).

CONCLUSIONS

Incidence of peripheral neuropathy in the 40 mg cohort was extremely high and, although lower, the rate in the 30 mg cohort was nonetheless unacceptably high.

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.

Toxicity associated with stavudine dose reduction from 40 to 30 mg in first-line antiretroviral therapy

Background

To compare the incidence and timing of toxicity associated with the use of a reduced dose of stavudine from 40 to 30 mg in first-line antiretroviral therapy (ART) for HIV treatment and to investigate associated risk factors.

Methods

Multicohort study including 23 HIV programs in resource-limited countries. Adults enrolled between January 2005 and December 2009. Four-year rates of all-cause and stavudine-specific toxicity were estimated. Multilevel mixed-effect Poisson and accelerated failure models were used to investigate factors associated with toxicity and timing of diagnosis.

Findings

A total of 48,785 patients contributed 62,505 person-years of follow-up. Rate of all-cause toxicity was 7.80 (95%CI 7.59–8.03) per 100 person-years, but varied greatly across sites (range 0.41–21.76). Patients treated with stavudine 40 mg had higher rates of toxicity (adjusted rate ratio [aRR] 1.18, 95%CI 1.06–1.30 during the first year of ART; and 1.51, 95%CI 1.32–1.71 during the second year). Women, older age, initial advanced clinical stage, and low CD4 count were associated with increased toxicity rate ratios. Timing of lipodystrophy and peripheral neuropathy diagnosis were 12% and 13% shorter, respectively, in patients treated with stavudine 40 mg than in those receiving 30 mg stavudine dose (P = 0.03 and 0.07, respectively).

Insterpretation

Higher rates of drug-related toxicity were reported in patients receiving stavudine 40 mg compared with 30 mg, and the time to toxicity diagnosis was shorter in patients treated with the higher dose. Higher rates of toxicity were observed during the first two years of ART.

In silico study supports the efficacy of a reduced dose regimen for stavudine

Stavudine (d4T) is used extensively as part of HAART in resource poor settings, despite its toxicities. The revised WHO guidelines specify replacement of d4T with less toxic but more expensive drugs when feasible, and that d4T doses be standardized to 30 mg twice daily (bid) (irrespective of body-weight), from the approved 40 mg bid in adults (body-weight ≥60 kg). Therefore, an in silico population pharmacokinetic and biochemical model was utilized to compare relative efficacies of the two doses in humans. Assessment of predicted quartile ranges of simulated concentrations of the triphosphate of d4T suggested sufficient trough concentrations to inhibit wild type HIV-1 reverse transcriptase at the reduced dose, lending support to the revised WHO recommendations.

From old to new nucleoside reverse transcriptase inhibitors: changes in body fat composition, metabolic parameters and mitochondrial toxicity after the switch from thymidine analogs to tenofovir or abacavir

INTRODUCTION

Thymidine analogs zidovudine (AZT) and stavudine (d4T) have been widely used because of their antiviral activity against HIV, but at the expense of high toxicity, mainly related to mitochondrial damage. Many studies have been performed replacing AZT or d4T with newer nucleoside analogs reverse transcriptase inhibitors (NRTIs) with less toxicity, such as tenofovir (TDF) or abacavir (ABC), maintaining virological efficacy.

AREAS COVERED

Relevant literature was identified using a PubMed search of articles published up to June 2010. Search terms included: 'thymidine analogs', 'stavudine', 'zidovudine', 'd4T', 'AZT', 'ZDV', 'treatment switch'. Original articles in which d4T or AZT had been replaced by TDF or ABC as switch strategies (with undetectable viral load) were reviewed where information about body fat distribution, mitochondrial functionality and/or plasma lipid parameters were available. Relevant references from these articles were also considered. Only studies performed in adult patients (18 years or older) are included. The readers will gain a better understanding of the toxicity caused by thymidine analogs, the treatment alternatives and the benefits observed after treatment switch to newer NRTIs.

EXPERT OPINION

Thymidine analogs AZT and d4T yield considerable toxicity and proactive switch to newer NRTIs such as TDF or ABC is necessary in order to avoid or partially reverse such side effects.

d4T: keep it or abandon it?

Stavudine is a nucleoside analogue used widely for first-line treatment of HIV in developing and middleincome countries. The World Health Organization recommended that all patients should switch to stavudine (30mg BID). However, there is evidence from the dose-ranging trials that patients with body weight below 60kg should use a dose of 20mg BID. For patients who show adverse events on stavudine, a switch to other nucleoside analogues can be considered. This article reviews d4T to study if it should be kept or abandoned.

LIPODYSTROPHY SYNDROME IN HIV-INFECTED CHILDREN ON HAART

Lipodystrophy syndrome (LD) is common in HIV-infected children, particularly those taking didanosine, stavudine or zidovudine. Lipo-atrophy in particular causes major stigmatisation and interferes with adherence. In addition, LD may have significant long-term health consequences, particularly cardiovascular. Since the stigmatising fat distribution changes of LD are largely permanent, the focus of management remains on early detection and arresting progression. Practical guidelines for surveillance and avoidance of LD in routine clinical practice are presented. The diagnosis of LD is described and therapeutic options are reviewed. The most important therapeutic intervention is to switch the most likely offending antiretroviral to a non-LD-inducing agent as soon as LD is recognised. Typically, when lipoatrophy or lipohypertrophy is diagnosed the thymidine nucleoside reverse transcriptase inhibitor (NRTI) is switched to a non-thymidine agent such as abacavir (or tenofovir in adults). Where dyslipidaemia is predominant, a dietician review is helpful, and the clinician may consider switching to a protease inhibitor-sparing regimen or to atazanavir.

Antiretroviral therapy-associated toxicities in the resource-poor world: the challenge of a limited formulary

Toxicities related to antiretroviral therapy make long-term adherence to therapy difficult for patients and present challenges to providers, especially those in the resource-poor world who work with a limited formulary. In resource-poor settings, where limited drug options are the rule, when and how to change therapy are especially difficult problems. Drugs such as stavudine and didanosine are associated with serious metabolic complications, such as lactic acidosis, pancreatitis, and peripheral neuropathy. Antiretroviral agents associated with fewer metabolic effects, such as tenofovir and abacavir, remain widely unavailable. Because the current formulary restrictions appear to be unlikely to change quickly, providers in resource-poor countries must be familiar with the common adverse events-including metabolic complications, hypersensitivity reactions, anemia, and liver enzyme abnormalities-and must understand how to manage them with what is locally available. Most importantly, to avoid drug toxicities, a larger formulary is needed in resource-poor settings, and this must be a high priority for policy makers and health care professionals involved in treating human immunodeficiency virus infection globally.

[Efficacy and safety of a reduced-dose of stavudine in HIV-infected patients under immunological and virological stable conditions]

BACKGROUND AND OBJECTIVE

Stavudine (d4T) has shown a favourable short and long-term tolerability profile. Nevertheless, its usage is currently decreasing due to some safety concerns. We aimed to evaluate the efficacy and safety of d4T low-dose-based regimens.

PATIENTS AND METHOD

This was a multicenter and retrospective review chart of patients receiving standard doses of d4T for > or = 6 months (weight > 60 kg: 40 mg/12 h; weight < 60 kg: 30 mg/12 h) and having undetectable viral load for at least 3 months before the d4T dose reduction (weight > 60 kg: 30 mg/12 h; weight < 60 kg: 20 mg/12 h). Immunological and viral parametres, lipid profile and side effects were determined.

RESULTS

A total of 982 patients were included. The main reason for reducing the dose was prevention of toxicity (76%). After 6 months of follow-up, 97% and 84% patients had less than 400 and 50 cp/ml, respectively, and the CD4 cell count increased by 38 cel/ml. Lipids, lipodystrophy and peripheral polineuropathy improved but there was no statistical significance.

CONCLUSIONS

A d4T dose reduction in an immuno-virologically stable population does not affect treatment efficacy. Longer follow-ups are required to confirm improvements in the safety profile.

High Doses of Stavudine Induce Fat Wasting and Mild Liver Damage without Impairing Mitochondrial Respiration in Mice

Objective

Stavudine (d4T), a nucleoside reverse-transcriptase inhibitor (NRTI), can induce lipoatrophy, fatty liver, hyperlactataemia and abnormal liver tests. NRTI toxicity is usually ascribed to mitochondrial DNA (mtDNA) depletion and impaired mitochondrial respiration. However, NRTIs could have effects unrelated to mtDNA. Recently, we reported that 100 mg/kg/day of d4T stimulated fatty acid oxidation (FAO) in mouse liver, and reduced body fatness without depleting white adipose tissue (WAT) mtDNA. We hypothesized that higher d4T doses could further reduce adiposity, while inhibiting hepatic FAO.

Methods

Mice were treated for 2 weeks with d4T (500 mg/kg/day), L-carnitine (200 mg/kg/day) or both drugs concomitantly. Body fatness was assessed by dual energy X-ray absorptiometry, and investigations were performed in plasma, liver, muscle and WAT.

Results

D4T reduced the gain of body adiposity, WAT leptin, whole body FAO and plasma ketone bodies, and increased liver triglycerides and plasma aminotransferases with mild ultrastructural abnormalities in hepatocytes. Plasma lactate and respiratory chain activities in tissues were unchanged. Stearoyl-CoA desaturase (SCD-1), an enzyme negatively regulated by leptin, was overexpressed in liver. High doses of β-aminoisobutyric acid (BAIBA), a d4T catabolite, increased plasma ketone bodies. Although L-carnitine did not correct body adiposity, it prevented d4T-induced impairment of FAO and liver abnormalities.

Conclusions

D4T overdosage triggers fat wasting, leptin insufficiency and mild liver damage, without causing respiratory chain dysfunction. Overexpression of SCD-1 reduces fatty acid oxidation and overcomes the stimulating effect of BAIBA on hepatic FAO. L-carnitine does not correct leptin insufficiency but prevents d4T-induced impairment of FAO and liver damage.

The Impact of Reducing Stavudine dose versus switching to tenofovir on plasma lipids, body composition and mitochondrial function in HIV-infected patients

Background

Stavudine (d4T)-containing regimens are associated with a potential for lipoatrophy and dyslipidaemia. We assessed the safety and efficacy of reducing the dose of stavudine compared with switching to tenofovir or maintaining the standard dose of d4T.

Methods

Clinically stable HIV-infected patients receiving antiretroviral therapy containing stavudine 40 mg twice daily with a plasma HIV RNA <200 copies/ml for at least 6 months were randomized to maintain stavudine 40 mg twice daily (d4T40 arm), to reduce to 30 mg twice daily (d4T30 arm), or to switch from d4T to tenofovir (TDF arm).

Results

Fifty-eight (93% male) patients were included: 22 in the d4T40 arm, 19 in the d4T30 arm and 17 in TDF arm. At baseline, median time on d4T was 6 years (interquartile range [IQR] 2.6–7.1), median age 43 years (IQR 36–51) and median CD4+ T-cell count was 587/mm3 (IQR 329–892). At week 24, median limb fat changes (g) were as follows: d4T40=-182 (95% CI: -469—5); d4T30=527 (95% CI: -343–694); and TDF=402 (95% CI: 130–835; d4T40 versus TDF, P=0.0003). Significant differences between median values of laboratory parameters were detected: triglycerides (mg/dl): d4T40=19; d4T30=-23 and TDF=-79 (d4T40 versus TDF, P=0.03); and total cholesterol (mg/dl): d4t40=22, d4T30=-4, and TDF=-28 (d4T40 versus TDF, P=0.04). No significant difference was observed in mitochondrial function assessed in peripheral blood mononuclear cells.

Conclusions

Although both strategies were associated with a trend toward a decrease in plasma lipids and an increase in body fat, the only significant changes were observed among those who switched to tenofovir.

Changes in the peripheral blood mtDNA levels in naive patients treated by different nucleoside reverse transcriptase inhibitor combinations and their association with subsequent lipodystrophy

Nucleoside reverse transcriptase inhibitors (NRTIs) differ in the type and severity of adverse effects resulting from mitochondrial abnormalities. mtDNA in peripheral blood mononuclear cells (PBMCs) was measured during the first 12 months of different NRTIs combinations and its association with clinical lipodystrophy was estimated. Extended follow-up of a randomized trial, ALBI-ANRS 070, including antiretroviral naive patients was conducted. Total DNA was extracted from available cryopreserved PBMCs at baseline and months 6 and 12. Nuclear and mitochondrial genes were amplified using a real-time PCR assay. Clinical lipodystrophy was assessed 30 months after randomization using a standardized questionnaire. A logistic regression analysis assessed the value of mtDNA to predict lipodystrophy. Mean mtDNA level (copies/cell) significantly decreased from 5847 at baseline to 3176 at month 12 (p < 0.0001). In the zidovudine + lamivudine (ZDV + 3TC) arm (n = 37), the mean mtDNA was 6098, 6807, and 3725 copies/cell for baseline, month 6, and month 12, respectively. In the stavudine + didanosine (d4T + ddI) arm (n = 40), the mean values were 5616, 5731, and 2648 copies/cell, respectively. The proportion of patients in the lowest quartile of mtDNA (<1421 copies/cell) at month 12 was higher in 18 patients with lipodystrophy (44%) than in 28 without lipodystrophy (7%) (p = 0.008). At 12 months, a larger reduction of mtDNA from baseline was observed in those started on the d4T + ddI arm. Furthermore, a low mtDNA level at month 12 was associated with the subsequent development of lipodystrophy. This marker may be of value for the early prevention of lipodystrophy in treated HIV-infected patients.