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Background: Antiretroviral therapy (ART)-controlled HIV-infected patients have elevated levels of systemic inflammatory markers, C-reactive protein (CRP) and interleukin (IL)-6, which correlate with increased cardiovascular risk and/or mortality. Persistent low-level viral replication could be involved in this inflammatory state. We evaluated whether residual viral load (VL) correlated with the level of systemic inflammatory/immune markers in ART-controlled HIV-infected patients., Methods: We evaluated 122 antiretroviral-controlled patients with VL 1-500 copies/ml for circulating levels of high-sensitivity (hs)CRP, hsIL-6, IL-8, soluble (s)CD14 and soluble tumour necrosis factor (TNF) receptors, sTNFR1 and sTNFR2., Results: The patients were 80.3% men, the median age was 47 years, the median CD4(+) T-cell count was 519 cells/mm(3), the median nadir CD4(+) T-cell count was 180 cells/mm(3), the median VL was 28 copies/ml and the median body mass index was 23.3 kg/m(2). The median (range) values for IL-6, CRP, IL-8, sCD14, sTNFR1 and sTNFR2 were 0.685 pg/ml (0.15-5.46), 1.8 mg/l (0.2-9.7), 10.0 pg/ml (1.6-71.1), 1,174 ng/ml (214-3,145), 1,112 pg/ml (583-5,834) and 2,412 pg/ml (1,142-7,688), respectively. IL-6 values correlated positively with HIV VL (rho=0.217, P=0.017). The VL threshold value for significantly increased IL-6 was 31 copies/ml (P=0.023). IL-6 values correlated with markers of immune dysfunction: the CD4/CD8 ratio (rho=-0.248, P=0.011), CD4 nadir level (rho=-0.186, P=0.04) and nadir CD4/CD8 ratio (rho=-0.257, P=0.008). They negatively correlated with markers of immune activation sCD14 (rho=-0.236, P=0.011) and IL-8 (rho=-0.290, P=0.002). We found no correlation between VL and CRP or other markers of inflammation/immune dysfunction including sTNFR1, sTNFR2, sCD14 and IL-8., Conclusions: We report here that low-range IL-6 levels correlated with low-range VL and inversely with sCD14 and IL-8. Our findings suggest that maintaining VL<30 copies/ml in HIV-infected patients might therefore reduce IL-6.

Background: HIV-infected patients under antiretroviral therapy that includes HIV protease inhibitors (PIs) are prone to develop a complex metabolic syndrome including insulin resistance, lipodystrophy and hypertension. Whether hypertension and cardiovascular events could result from the adipocyte renin angiotensin system (RAS) overactivation has never been investigated., Methods: Primary human adipocytes and 3T3-F442A murine adipocytes were incubated with lopinavir or atazanavir boosted with ritonavir, with or without the angiotensin II type-1 receptor (AT1R) blockers (ARBs), irbesartan or telmisartan, and the peroxysome proliferator-activated receptor-gamma (PPAR-gamma) regulators, rosiglitazone and GW9662. Adipose RAS activation and adipocyte functions were evaluated., Results: The ritonavir-boosted PIs activated the adipose RAS in human and murine adipocytes as shown by the overexpression of AT1R protein, angiotensinogen messenger RNA and the amplified effect of angiotensin II on extracellular signal-regulated kinase 1/2 activity. ARBs prevented the PI effect on RAS activation (AT1R overexpression and signalling) and adipocyte functions (dedifferentiation, insulin resistance, oxidative stress and inflammation). Consistent with a role of PPAR-gamma signalling in PI-induced RAS activation, the PPAR-gamma agonist (rosiglitazone) normalized PI-induced AT1R overexpression and adipocyte dysfunction. Conversely, the PPAR-gamma antagonist (GW9662) induced AT1R overexpression and reduced the beneficial effect of telmisartan on PI toxicity., Conclusions: We report that two frequently prescribed PI combinations could activate the adipose RAS in cultured cells, in part through a PPAR-gamma-dependant signalling pathway. Our data suggest a role for the adipose RAS in the development of hypertension in HIV-infected patients under PI treatment, and point out the potential use of ARBs to decrease PI adverse effects.

Background: Although thiazolidinediones have been shown to increase subcutaneous fat in congenital lipodystrophy, rosiglitazone did not show convincing results in HIV lipoatrophy. We assess a potential specific effect of pioglitazone in this setting., Methods: One-hundred and thirty HIV-1-infected adults with self-reported lipoatrophy confirmed by physical examination were randomized to receive pioglitazone 30 mg once daily (n=64) or placebo (n=66) for 48 weeks. Changes in limb fat between weeks 0 and 48 were measured using dual-energy Xray absorptiometry. Subcutaneous and visceral fat was measured by single-slice computed tomography; fasting plasma measurements of glucose, insulin and lipids levels were recorded., Results: Limb fat increased by 0.38 kg in the pioglitazone group and 0.05 kg in the placebo group at week 48 (mean difference 0.33 kg, 95% confidence interval [CI] 0.10-0.56; P=0.051) by intention-to-treat analysis. In patients not receiving stavudine, an increase of 0.45 kg versus 0.04 kg was observed (mean difference, 0.40 kg, 95% CI 0.12-0.69; P=0.013), but this was not seen in patients on stavudine (n=36; P=0.404). Overall, there was no significant difference in subcutaneous abdominal fat or in visceral fat areas on computed tomography at L4 vertebra. The lipid profile was not significantly different at week 48 except for levels of high-density lipoprotein cholesterol, which was improved in the pioglitazone group (+0.08 mmol/l versus -0.08; P=0.005)., Conclusions: Pioglitazone 30 mg once daily for 48 weeks improved limb fat atrophy in antiretroviral-treated HIV-1-infected patients, although clinical benefits were not perceived by the patients. Treatment did lead to a favourable lipid profile, however, suggesting that this thiazolidinedione should be considered in the context of HIV-related lipoatrophy.

Objectives: Adipose tissue from patients with HIV-related lipodystrophy presents a state of chronic inflammation. Altered expression of cytokines/adipokines and macrophage infiltration could be involved in patients' insulin resistance and lipoatrophy. We tested whether antiretrovirals affected adipokine release by human subcutaneous adipocytes and cytokine/chemokine production by human macrophages and examined whether reactive oxygen species (ROS) hyperproduction was related to the effect of antiretrovirals., Methods: Differentiated human adipocytes and PMA-THP-1 macrophages were treated with protease inhibitors (PIs: indinavir, nelfinavir, amprenavir, lopinavir, ritonavir and atazanavir) or nucleoside reverse transcriptase inhibitors (NRTIs: stavudine, zidovudine and abacavir) for 24-48 h without or with diphenylene iodonium (DPI), an inhibitor of oxidative stress. Lipid content was assessed by Oil Red O staining and ROS production by nitroblue tetrazolium (NBT) reduction. Cytokine/chemokines, adiponectin and leptin release was evaluated by ELISA or multiplex assays., Results: In human adipocytes, PIs and NRTIs (except amprenavir, atazanavir and abacavir) reduced lipid content, adiponectin and leptin release and increased in parallel ROS production and monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-6 release. The effects of PIs, but not of NRTIs, were prevented by the addition of DPI. In PMA-THP-1 macrophages, all PIs, but no NRTI, increased macrophage inflammatory protein-1 alpha and MCP-1 release. Lopinavir, nelfinavir, zidovudine and stavudine markedly increased ROS production and release of IL-1 beta and tumour necrosis factor-alpha., Conclusions: Some PIs altered adipokine secretion and lipid content through ROS production in human subcutaneous adipocytes. Thymidine analogues altered adipocyte functions but their effect on adipokine secretion was not reverted by ROS production inhibition. Increased chemokine/cytokine production by adipocytes and macrophages could be involved in macrophage recruitment and participate in lipoatrophy and insulin resistance.

Objective: To examine the reversibility of adipose tissue alterations in HIV-infected patients after a 6-month interruption of antiretroviral therapy (ART)., Methods: Forty HIV-infected patients on stable effective ART were enrolled, 33 of them completed the study. Patients underwent a physical examination, laboratory tests and needle biopsy of subcutaneous abdominal adipose tissue both at inclusion and at month 6. Changes in fat morphology, mitochondrial DNA (mtDNA) content and gene expression were examined in 29, 23 and 20 patients, respectively., Results: Body fat distribution was not clearly modified at month 6. Adipose tissue inflammation improved markedly, with fewer infiltrating macrophages and fewer tumour necrosis factor alpha (TNFalpha)- and interleukin 6 (IL6)-expressing cells. Expression of peroxisome proliferator-activated receptor gamma (PPAR-gamma) and of markers of mitochondrial function and biogenesis (cytochrome oxidase 2 and PPAR-gamma coreceptor 1alpha) improved after protease inhibitor (PI) withdrawal. In patients who stopped taking stavudine or zidovudine, the number of TNFalpha- and IL6-expressing cells was lower at month 6 than at month 0, and so was CD68 expression, a macrophage marker. Adipocyte mitochondrial status also improved, with lower mitochondrial density and cytochrome oxidase 4 mRNA levels, and higher mtDNA content. Sterol regulatory element binding protein 1 mRNA levels increased, reflecting better adipocyte differentiation., Conclusions: A 6-month ART interruption markedly improved adipose tissue functions, although fat distribution did not visibly change. Stavudine and zidovudine were associated with marked inflammation, which improved when these drugs were withdrawn; they also had a negative effect on differentiation and mitochondrial status. PIs were also associated with altered adipocyte differentiation and mitochondrial status. These data clearly show the detrimental effect of antiretroviral drugs, in particular thymidine analogues, on adipose tissue and argue for switch strategies sparing these drugs.

Objective: The lipodystrophy syndrome is a major adverse effect of highly active antiretroviral therapy (HAART), associated with altered circulating levels and adipose tissue mRNA expression of proinflammatory cytokines interleukin-6 (IL-6) and tumour necrosis factor (TNF)alpha, and adiponectin. Proinflammatory cytokines and adiponectin, which are secreted by adipose tissue, regulate fat metabolism, insulin sensitivity and adipose cell apoptosis. We examined the direct effects of individual antiretrovirals on lipid metabolism and cytokine and adiponectin production by cultured adipocytes., Methods: Differentiating 3T3-F442A cells and differentiated 3T3-L1 adipocytes were treated for 12 or 4 days, respectively, with protease inhibitors (PIs) indinavir, nelfinavir, amprenavir, lopinavir and ritonavir, or nucleoside reverse transcriptase inhibitors (NRTIs) stavudine and zidovudine, at near-Cmax concentrations. Lipid metabolism was estimated by Oil Red O staining of intracellular lipids, mRNA expression of fatty acid synthase and adipocyte lipid binding protein 2, and insulin activation of lipogenesis. Apoptosis was estimated by flow cytometry. The expression and secretion of proinflammatory cytokines (IL-6, TNFalpha and IL-1beta) and adiponectin were evaluated by real-time reverse transcription PCR and ELISA., Results: Chronic treatment of 3T3-F442A differentiating adipocytes and differentiated 3T3-L1 adipocytes with PIs and NRTIs reduced lipid accumulation, mRNA expression of lipid markers and insulin-induced lipogenesis. IL-6, TNFalpha, IL-1beta and adiponectin expression and secretion were markedly altered in differentiating 3T3-F442A adipocytes. PIs had either no effect on differentiated 3T3-L1 adipocytes (TNFalpha expression and sucretion) or their effect was less marked than in 3T3-F442A cells. Indinavir and amprenavir did not alter cytokine secretion and expression by mature adipocytes. The effects of stavudine and zidovudine on differentiating and mature adipocytes were similar, despite the difference in treatment procedure. The drugs with the strongest effect on TNFalpha expression also increased adipocyte apoptosis, in contrast to the drugs that only moderately increased TNFalpha expression., Conclusions: These results suggest that increased cytokine and decreased adiponectin secretion and expression induced by some PIs and NRTIs may contribute to the adipose tissue loss (via apoptosis and lipid leakage) and insulin resistance associated with the lipodystrophy syndrome.

Objective: To achieve a better understand of the pathophysiology of HIV-related lipoatrophy, we compared the mRNA expression of adipocytokines in fat samples from patients and healthy HIV-seronegative controls together with fat morphology and we studied the relationship between changes in fat morphology, adipocytokine expression, markers of adipose tissue differentiation and whole body insulin sensitivity., Design: Cross-sectional analytical study., Subjects and Methods: The mRNA expression of adipocytokines and transcriptional factors in fat samples from 26 patients with peripheral lipoatrophy (all under anti-retroviral therapy associating protease inhibitor and nucleoside-analogue reverse transcriptase inhibitors) and from 16 non-HIV-infected controls was measured by real time quantitative RT-PCR. Fat morphology was assessed histologically on a subgroup of 10 patients and six controls: collagen fibres by Sirius Red staining, apoptosis by the TUNEL technique, vessels by smooth muscle alpha-actin staining and macrophages by CD68 staining. Insulin resistance was assessed by using the homeostasis model assessment., Results: The patients' fat showed higher values of apoptosis (P=0.005), fibrosis (P<0.05), vessel density (P=0.001) and macrophage infiltration (P<0.05) than the controls' fat, together with lower adiponectin and leptin mRNA levels and higher interleukin (IL)-6 and tumour necrosis factor (TNF)alpha mRNA levels. TNFa and IL-6 expression correlated positively with the level of apoptosis (P=0.05 and P<0.05, respectively) and negatively with CCAAT-enhancer binding protein (C/EBP)alpha (P<0.001 and P<0.05, respectively). Apoptosis correlated negatively with the expression level of sterol-regulatory-element-binding-protein-1c (SREBP1c) (P=0.01) and C/EBPalpha (P=0.01) whilst the vessel density correlated negatively with SREBP1c (P<0.005), C/EBPalpha (P=0.001) and beta (P=0.001). Adiponectin and leptin expression correlated positively with each other, and also with adipogenic marker expression and overall insulin sensitivity. These relationships were also present when the patient group was studied separately. Finally, fat morphological abnormalities correlated positively with whole body insulin resistance., Conclusions: Adipose tissue from patients with HIV-1-related lipoatrophy shows increased apoptosis, together with decreased adipocyte differentiation. Increased TNFalpha and IL-6 expression could be a major phenomenon linking these alterations. Decreased adiponectin and leptin expression, which may result from decreased adipocyte differentiation, could be involved in the observed whole body insulin resistance.