Differential adipose tissue gene expression profiles in abacavir treated patients that may contribute to the understanding of cardiovascular risk: a microarray study.

OBJECTIVE: To compare changes in gene expression by microarray from subcutaneous adipose tissue from HIV treatment naïve patients treated with efavirenz based regimens containing abacavir (ABC), tenofovir (TDF) or zidovidine (AZT). DESIGN: Subcutaneous fat biopsies were obtained before, at 6- and 18-24-months after treatment, and from HIV negative controls. Groups were age, ethnicity, weight, biochemical profile, and pre-treatment CD4 count matched. Microarray data was generated using the Agilent Whole Human Genome Microarray. Identification of differentially expressed genes and genomic response pathways was performed using limma and gene set enrichment analysis. RESULTS: There were significant divergences between ABC and the other two groups 6 months after treatment in genes controlling cell adhesion and environmental information processing, with some convergence at 18-24 months. Compared to controls the ABC group, but not AZT or TDF showed enrichment of genes controlling adherence junction, at 6 months and 18-24 months (adjusted p<0.05) and focal adhesions and tight junction at 6 months (p<0.5). Genes controlling leukocyte transendothelial migration (p<0.05) and ECM-receptor interactions (p = 0.04) were over-expressed in ABC compared to TDF and AZT at 6 months but not at 18-24 months. Enrichment of pathways and individual genes controlling cell adhesion and environmental information processing were specifically dysregulated in the ABC group in comparison with other treatments. There was little difference between AZT and TDF. CONCLUSION: After initiating treatment, there is divergence in the expression of genes controlling cell adhesion and environmental information processing between ABC and both TDF and AZT in subcutaneous adipose tissue. If similar changes are also taking place in other tissues including the coronary vasculature they may contribute to the increased risk of cardiovascular events reported in patients recently started on abacavir-containing regimens.

Evidence for a shift to anaerobic metabolism in adipose tissue in efavirenz-containing regimens for HIV with different nucleoside backbones.

BACKGROUND: Antiretroviral (ARV) treatment has been associated with abnormalities in lipid and mitochondrial metabolism. We compared patterns of gene expression in the subcutaneous adipose tissue (SAT) of HIV-positive subjects before and after 18-24 months of ARV therapy with HIV-negative controls. METHODS: HIV patients naive to ARV were randomized to receive zidovudine (AZT), lamivudine (3TC) with efavirenz (EFV) or tenofovir disoproxil fumarate (TDF) with emtricitabine (FTC) and EFV. Healthy controls (n=15) were matched for age, ethnicity and gender. Patients on a regimen containing abacavir (ABC), 3TC and EFV for 18-24 months were also tested. Genes involved in adipocyte glucocorticoid, lipid and mitochondrial metabolism, and adipocyte differentiation, were profiled with real-time PCR. RESULTS: AZT led to increased visceral adipose tissue (VAT; P=0.012) and VAT:SAT ratio (P=0.036), whereas TDF increased SAT (P=0.047) and peripheral fat/lean body mass ratio (P=0.017). HIV treatment-naive patients had lower plasma lipoprotein lipase (LPL) activity (P=0.0001) versus controls (remaining below controls after ARV; P=0.038-0.0001). The overall pattern of gene expression was similar across all treatment groups, being most marked with AZT and least with TDF. There was up-regulation of peroxisome proliferator-activated receptor-γ coactivator-1α, uncoupling protein-2 and hexose 6-phosphate dehydrogenase, and down-regulation of nuclear respiratory factor-1, cytochrome oxidase B, cytochrome c oxidase-4, uncoupling protein-3, 11ß-hydroxysteroid dehydrogenase type-1, glucocorticoid receptor-α, fatty acid synthase, fatty acid binding protein-4, LPL and hormone sensitive lipase (18-24 months post-treatment versus pretreatment levels and controls; P<0.05 to <0.0001). CONCLUSIONS: The decreased expression of genes involved in lipid and mitochondrial metabolism 18-24 months post-ARV treatment in SAT of HIV patients, in conjunction with the increase in uncoupling protein-2 and decrease in cytochrome oxidase B gene expression, provides evidence of mitochondrial dysfunction and a shift to anaerobic metabolism within SAT in EFV-containing ARV regimens.

Adipocyte differentiation, mitochondrial gene expression and fat distribution: differences between zidovudine and tenofovir after 6 months.

BACKGROUND: Abnormal lipid metabolism and cell oxidative mechanisms are reported in patients on antiretroviral treatment. We compared the expression of several key adipocyte genes in HIV-infected patients randomized to antiretroviral regimens containing zidovudine (AZT) or tenofovir disoproxil fumarate (TDF). METHODS: Subcutaneous fat was sampled from 32 HIV-positive treatment-naive patients before and 6 months after randomization to AZT/lamivudine/efavirenz (n=15) or TDF/emtricitabine/efavirenz (n=17) plus 15 HIV-negative matched controls. Expression of genes involved in adipocyte differentiation, lipid metabolism, mitochondrial function and glucocorticoid generation were profiled using real-time PCR. Lipoprotein lipase and hepatic lipase activity were assessed. RESULTS: Before treatment, 11beta-hydroxysteroid dehydrogenase expression was down-regulated compared with controls. Following 6 months treatment with AZT, there was a significant increase in visceral adipose tissue (VAT; P=0.02) and the ratio of VAT to subcutaneous adipose tissue (P=0.008), down-regulation of cytochrome B (P=0.003) and cytochrome oxidase (COX)-3 gene expression (P=0.03), up-regulation of NADH dehydrogenase (P=0.008) and nuclear-encoded COX-4 (complex IV) gene expression (P=0.012). Genes involved with adipocyte cortisol generation, fatty acid metabolism and the tricarboxylic acid cycle were up-regulated. In the TDF-treated patients, there was no significant change in regional body fat or mitochondrial genes compared with pretreatment values. Changes in the expression of genes involved with cortisol and fatty acid metabolism were less marked with TDF. CONCLUSIONS: Interference with the mitochondrial electron transport chain appears to occur early in an AZT-containing regimen and occurs at a time when there is increased visceral fat and up-regulation of genes involved with adipocyte differentiation and fatty acid flux.

A randomized comparative trial of continued zidovudine/lamivudine or replacement with tenofovir disoproxil fumarate/emtricitabine in efavirenz-treated HIV-1-infected individuals.

BACKGROUND: Long-term antiretroviral therapy dramatically reduces HIV-related morbidity and mortality but is also associated with metabolic and morphological changes and requires high levels of adherence. METHODS: A randomized, 48-week, open-label, comparative study of continuation of twice-daily zidovudine/lamivudine or replacement with once-daily tenofovir disoproxil fumarate/emtricitabine in individuals on successful efavirenz-based antiretroviral therapy. Limb fat mass was assessed by dual x-ray absorptiometry in a subset of participants through week 48. RESULTS: Two hundred thirty-four individuals were randomized and treated (117 each to continue or switch) with 206 subjects completing 48 weeks of study. Five percent subjects in the continue group and 3% subjects in the switch group discontinued due to adverse events. By intent-to-treat, missing = failure analysis, no differences in virological efficacy were observed at any time point (week 48 <50 copies/mL continue 85%, switch 88%). At week 24, switching was associated with significant increases in hemoglobin (mean difference 0.37 g/dL, 95% confidence interval: 0.15 to 0.58 g/dL, P < 0.001) and significant declines in total cholesterol and triglycerides. In the dual x-ray absorptiometry substudy (n = 100), fat was preserved or increased in the switch group but declined in the continue group (mean difference 448 g, 95% confidence interval: 57 to 839 g, P = 0.025). Individuals with longer exposure to zidovudine and lower baseline limb fat experienced less limb fat increase after switching. No differences in renal adverse events were observed between groups. CONCLUSIONS: Switching from zidovudine/lamivudine to tenofovir disoproxil fumarate/emtricitabine in persons on efavirenz therapy maintains virological control, establishes a once-daily regimen, results in improvements in hemoglobin and key lipid parameters, and preserves and restores limb fat relative to continuation of zidovudine/lamivudine.

A randomized controlled trial of a replication defective (gH deletion) herpes simplex virus vaccine for the treatment of recurrent genital herpes among immunocompetent subjects.

BACKGROUND: A replication incompetent herpes virus lacking the glycoprotein H gene has been developed as a potential therapeutic vaccine for genital herpes. GOAL: To determine vaccine efficacy on reducing HSV reactivation and clinical disease among immunocompetent persons with recurrent genital HSV-2 infection. STUDY DESIGN: Randomized multicenter placebo-controlled trial. Healthy volunteers who had six or more recurrences of genital herpes per year were randomized to receive injections of vaccine at 0 and 8 or 0, 4, and 8 or 0, 2, 4, and 8 weeks or placebo and were followed for subsequent recurrences for 1 year. RESULTS: The median times to first recurrence of genital herpes (40 days versus 30 days versus 37 days versus 42 days, respectively), mean number of recurrences (3 versus 3 versus 2.4 versus 1.9, respectively), and time to lesion healing of the first recurrence (8 days versus 7.8 days versus 7.4 days versus 7.5 days, respectively), were similar for all treatment groups. Asymptomatic viral shedding was detected by PCR in 61/74 (82%) persons performing daily sample collection following completion of the vaccination series. No differences were noted in the proportion of days with shedding between treatment groups (11.9% versus 17.2% versus 13.1% versus 16.4%, respectively). CONCLUSION: This replication incompetent HSV-2 vaccine lacking the glycoprotein H gene was safe but had no clinical or virologic benefit in the amelioration of genital HSV-2 disease among immunocompetent men and women.

Low density lipoprotein apolipoprotein B metabolism in treatment-naive HIV patients and patients on antiretroviral therapy.

BACKGROUND: Dyslipidaemia and lipodystrophy have been described in treated HIV patients and in a small percentage of untreated HIV patients. Lipodystrophy in these patients has been shown to be associated with a lower expression of low density lipoprotein (LDL) receptors. METHODS: We have investigated the effect of antiretroviral treatment with either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI) on body fat distribution and LDL apolipoprotein B (apoB) kinetics in 12 HIV-negative controls and 52 HIV-infected patients, including antiretroviral treatment-naive (TN) patients (n=13) and patients taking two nucleoside analogues plus either a PI (n=15) or an NNRTI (n=24). RESULTS: LDL cholesterol was not different between groups. Compared with the controls, LDL apoB absolute synthetic rate (ASR) and fractional catabolic rate (FCR) were lower and residence time (RT) was higher in the PI and NNRTI groups (P<0.05). In the TN patients, LDL ASR was lower (P<0.05) and there was a trend for a lower FCR and higher RT compared with the controls (P=0.07). LDL apoB pool size was greater in the PI group compared with the controls (P<0.05). In the PI group, patients on ritonavir (RTV)-containing regimens had a lower LDL apoB ASR (P=0.009) and a trend to a lower LDL apoB FCR and increased RT compared with non-RTV-containing PI regimens (P=0.05). There was a positive correlation between LDL apoB FCR and limb fat/lean body mass (P=0.004) in all subjects. CONCLUSIONS: Decreased LDL FCR, despite unchanged LDL cholesterol, was demonstrated in both treated and untreated HIV patients. It was more marked with RTV-containing regimens and was associated with reduced limb fat. The increased LDL RT may lead to an increased risk of atherogenesis thus contributing to the risk for cardiovascular disease in these patients.

Treatment failure of vaginal trichomoniasis in clinical practice.

We have conducted a retrospective study of treatment failure of Trichomonas vaginalis (TV) infection in a busy, urban genitourinary medicine clinic in Birmingham, UK, between 1998 and 2002. The prevalence of non-response to standard doses of metronidazole without any history of reinfection or nonadherence was 1.7% (28/1603) overall, and has significantly increased from 0.38% in 1999 to 3.5% in 2002 (P = 0.001, chi2 test). There were no associated demographic factors. The majority of patients (53% or 15/28) responded to either a repeat of standard (10/26) or higher oral dose (5/7) of metronidazole. A standardized treatment algorithm using a high dose of metronidazole may be useful in the absence of any new, efficacious non-imidazole-based TV therapy in the clinical management of persistent TV infection.

Antiretroviral treatment reduces very-low-density lipoprotein and intermediate-density lipoprotein apolipoprotein B fractional catabolic rate in human immunodeficiency virus-infected patients with mild dyslipidemia.

The relationship between antiretroviral treatment of HIV infection, body fat distribution, insulin resistance, and very-low-density lipoprotein (VLDL) and intermediate-density lipoprotein (IDL) apolipoprotein-B (apoB) kinetics was investigated in 55 HIV-infected patients taking two nucleoside analogs plus either a protease inhibitor (n = 15) or a nonnucleoside reverse transcriptase inhibitor (n = 25), 15 antiretroviral therapy-naive patients, and 12 HIV-negative controls. Compared with the controls, high-density lipoprotein cholesterol was reduced in all groups (P < 0.01). Plasma triglyceride was increased in patients taking protease inhibitors (P < 0.05). VLDL and IDL apoB fractional catabolic rate (FCR) was lower in all treatment groups (P < 0.05) compared with controls. Trunk fat, VLDL apoB absolute secretion rate, and insulin resistance were not different between groups. Peripheral fat was lower in the treated patients (P < 0.05) and correlated with duration of therapy (r = -0.55; P < 0.001). There was a positive correlation between peripheral fat and VLDL apoB FCR (P = 0.002) and IDL apoB FCR (P = 0.002) and a negative correlation with VLDL apoB pool size, VLDL cholesterol, and triglyceride (P < 0.03; P < 0.01; P < 0.002). These results suggest that mild dyslipidemia resulting from antiretroviral therapy is caused by a decrease in VLDL and IDL apoB FCR, which is associated with a loss of peripheral fat.

Valacyclovir for the suppression of recurrent genital herpes in human immunodeficiency virus-infected subjects.

To determine the efficacy and safety of valacyclovir (500 mg twice daily) for the suppression of recurrent genital herpes simplex virus infections in human immunodeficiency virus (HIV)-infected subjects, a randomized, double-blind, placebo-controlled, multicenter international trial was conducted. A total of 293 HIV-seropositive subjects receiving antiretroviral therapy were enrolled. The proportion of subjects who did not have a recurrence of genital herpes at 6 months was 65% among valacyclovir recipients versus 26% among placebo recipients (relative risk, 2.5; 95% confidence interval, 1.8-3.5). The time to first genital herpes recurrence was significantly shorter in the placebo group (median, 59 days) than in the valacyclovir group (median, >180 days). Valacyclovir was well tolerated; the incidence of adverse events for the 2 treatment groups was similar when the duration of treatment was considered. There were no episodes of thrombotic microangiopathy. Valacyclovir was safe and effective for the suppression of recurrent genital herpes infection in HIV-infected individuals.