Oxidative phosphorylation in HIV-1 infection: impacts on cellular metabolism and immune function

Human Immunodeficiency Virus Type 1 (HIV-1) presents significant challenges to the immune system, predominantly characterized by CD4+ T cell depletion, leading to Acquired Immunodeficiency Syndrome (AIDS). Antiretroviral therapy (ART) effectively suppresses the viral load in people with HIV (PWH), leading to a state of chronic infection that is associated with inflammation. This review explores the complex relationship between oxidative phosphorylation, a crucial metabolic pathway for cellular energy production, and HIV-1, emphasizing the dual impact of HIV-1 infection and the metabolic and mitochondrial effects of ART. The review highlights how HIV-1 infection disrupts oxidative phosphorylation, promoting glycolysis and fatty acid synthesis to facilitate viral replication. ART can exacerbate metabolic dysregulation despite controlling viral replication, impacting mitochondrial DNA synthesis and enhancing reactive oxygen species production. These effects collectively contribute to significant changes in oxidative phosphorylation, influencing immune cell metabolism and function. Adenosine triphosphate (ATP) generated through oxidative phosphorylation can influence the metabolic landscape of infected cells through ATP-detected purinergic signaling and contributes to immunometabolic dysfunction. Future research should focus on identifying specific targets within this pathway and exploring the role of purinergic signaling in HIV-1 pathogenesis to enhance HIV-1 treatment modalities, addressing both viral infection and its metabolic consequences.

Silk fibers assisted long-term 3D culture of human primary urinary stem cells via inhibition of senescence-associated genes: Potential use in the assessment of chronic mitochondrial toxicity

Despite being widely applied in drug development, existing in vitro 2D cell-based models are not suitable to assess chronic mitochondrial toxicity. A novel in vitro assay system mimicking in vivo microenvironment for this purpose is urgently needed. The goal of this study is to establish a 3D cell platform as a reliable, sensitive, cost-efficient, and high-throughput assay to predict drug-induced mitochondrial toxicity. We evaluated a long-term culture of human primary urine-derived stem cells (USC) seeded in 3D silk fiber matrix (3D USC-SFM) and further tested chronic mitochondrial toxicity induced by Zalcitabine (ddC, a nucleoside reverse transcriptase inhibitor) as a test drug, compared to USC grown in spheroids. The numbers of USC remain steady in 3D spheroids for 4 weeks and 3D SFM for 6 weeks. However, the majority (95%) of USC survived in 3D SFM, while cell numbers significantly declined in 3D spheroids at 6 weeks. Highly porous SFM provides large-scale numbers of cells by increasing the yield of USC 125-fold/well, which enables the carrying of sufficient cells for multiple experiments with less labor and lower cost, compared to 3D spheroids. The levels of mtDNA content and mitochondrial superoxide dismutase₂ [SOD2] as an oxidative stress biomarker and cell senescence genes (RB and P16, p21) of USC were all stably retained in 3D USC-SFM, while those were significantly increased in spheroids. mtDNA content and mitochondrial mass in both 3D culture models significantly decreased six weeks after treatment of ddC (0.2, 2, and 10 μM), compared to 0.1% DMSO control. Levels of complexes I, II, and III significantly decreased in 3D SFM-USC treated with ddC, compared to only complex I level which declined in spheroids. A dose- and time-dependent chronic MtT displayed in the 3D USC-SFM model, but not in spheroids. Thus, a long-term 3D culture model of human primary USC provides a cost-effective and sensitive approach potential for the assessment of drug-induced chronic mitochondrial toxicity.

3D Spheroids of Human Primary Urine-Derived Stem Cells in the Assessment of Drug-Induced Mitochondrial Toxicity

Mitochondrial toxicity (Mito-Tox) risk has increased due to the administration of several classes of drugs, particularly some life-long antiretroviral drugs for HIV+ individuals. However, no suitable in vitro assays are available to test long-term Mito-Tox (≥4 weeks). The goal of this study is to develop a 3D spheroid system of human primary urine-derived stem cells (USC) for the prediction of drug-induced delayed Mito-Tox. The cytotoxicity and Mito-Tox were assessed in 3D USC spheroids 4 weeks after treatment with antiretroviral drugs: zalcitabine (ddC; 0.1, 1 and 10 µM), tenofovir (TFV; 3, 30 and 300 µM) or Raltegravir (RAL; 2, 20 and 200 µM). Rotenone (RTNN, 10 µM) and 0.1% DMSO served as positive and negative controls. Despite only mild cytotoxicity, ddC significantly inhibited the expression of oxidative phosphorylation enzyme Complexes I, III, and IV; and RAL transiently reduced the level of Complex IV. A significant increase in caspase 3 and ROS/RNS level but a decrease in total ATP were observed in USC treated with ddC, TFV, RAL, and RTNN. Levels of mtDNA content and mitochondrial mass were decreased in ddC but minimally or not in TFV- and RAL-treated spheroids. Thus, 3D USC spheroid using antiretroviral drugs as a model offers an alternative platform to assess drug-induced late Mito-Tox.

Long-term treated HIV infection is associated with platelet mitochondrial dysfunction

HIV infection and antiretroviral therapy have been linked to mitochondrial dysfunction. The role of platelet mitochondrial dysfunction in thrombosis, immunoregulation and age-related diseases is increasingly appreciated. Here, we studied platelet mitochondrial DNA content (mtDNA_pl) and mitochondrial function in people living with HIV (PLHIV) and related this to platelet function. In a cohort of 208 treated PLHIV and 56 uninfected controls, mtDNA_pl was quantified, as well as platelet activation, platelet agonist-induced reactivity and inflammation by circulating factors and flow cytometry. In a subgroup of participants, the metabolic activity of platelets was further studied by mitochondrial function tests and the Seahorse Flux Analyzer. PLHIV had significantly lower mtDNA_pl compared to controls (8.5 copies/platelet (IQR: 7.0–10.7) vs. 12.2 copies/platelet (IQR: 9.5–16.6); p < 0.001), also after correction for age, sex and BMI. Prior zidovudine-use (n = 46) was associated with a trend for lower mtDNA_pl. PLHIV also had reduced ex vivo platelet reactivity and mean platelet volume compared to controls. MtDNA_pl correlated positively with both platelet parameters and correlated negatively with inflammatory marker sCD163. Mitochondrial function tests in a subgroup of participants confirmed the presence of platelet mitochondrial respiration defects. Platelet mitochondrial function is disturbed in PLHIV, which may contribute to platelet dysfunction and subsequent complications. Interventions targeting the preservation of normal platelet mitochondrial function may ultimately prove beneficial for PLHIV.

Symptoms of Toxicity and Plasma Cytochrome c Levels in Human Immunodeficiency Virus-infected Patients Receiving Anti-retroviral Therapy in Ghana: A Cross-sectional Study

BACKGROUND

Side effects and toxicity have posed a threat to the positive contribution of Antiretroviral Therapy (ART) in the management of human immunodeficiency virus (HIV) infection and Acquired Immune Deficiency Syndrome (AIDS). Symptoms of mitochondrial toxicity including myopathy, pancreatitis, hyperlipidaemia and lactic acidosis are found among HIVinfected patients on ART. To date, there is not a reliable biomarker for monitoring ART-related mitochondrial toxicity. Plasma level of Cytochrome c (Cyt-c) has been proposed as a potential biomarker for ART-related toxicity due to its strong association with apoptosis.

OBJECTIVE

The present study assessed toxicity and level of plasma Cyt-c among HIV-infected patients receiving ART in Ghana.

METHODS

A total of eighty (80) HIV patients were recruited into the study. Demographic data were obtained from personal interview and medical records. Plasma samples were screened for toxicity from sixty (60) participants due to limited resources, and plasma Cyt-c levels were determined using ELISA. Data were analyzed using Stata version 13.

RESULTS

Out of the 60 participants, 11 (18.3%) were found with symptoms of myopathy, 12 (20%) with pancreatitis, 21 (35%) with hyperlipidaemia and 36 (60%) with at least one of the symptoms. The concentration of plasma Cyt-c was higher (0.122 ng/ml) in patients with toxicity than in those without toxicity (0.05 ng/ml), though the difference was not statistically significant (p = 0.148). There was a weak correlation between plasma Cyt-c level and duration of ART (Spearman rho = 0.02, p = 0.89).

CONCLUSION

This study, therefore, demonstrated a high prevalence of ART-related toxicity and high levels of Cyt-c in HIV-infected patients in support of the argument that plasma Cyt-c levels are potential biomarkers for determining ART-related toxicity in HIV patients.

Heart Failure among People with HIV: Evolving Risks, Mechanisms, and Preventive Considerations

PURPOSE

People with HIV (PHIV) with access to modern antiretroviral therapy (ART) face a two-fold increased risk of heart failure as compared with non-HIV-infected individuals. The purpose of this review is to consider evolving risks, mechanisms, and preventive considerations pertaining to heart failure among PHIV.

RECENT FINDINGS

While unchecked HIV/AIDS has been documented to precipitate heart failure characterized by overtly reduced cardiac contractile function, ART-treated HIV may be associated with either heart failure with reduced ejection fraction (HFrEF) or with heart failure with preserved ejection fraction (HFpEF). In HFpEF, a "stiff" left ventricle cannot adequately relax in diastole-a condition known as diastolic dysfunction. Diastolic dysfunction, in turn, may result from processes including myocardial fibrosis (triggered by hypertension and/or immune activation/inflammation) and/or myocardial steatosis (triggered by metabolic dysregulation). Notably, hypertension, systemic immune activation, and metabolic dysregulation are all common conditions among even those PHIV who are well-treated with ART. Of clinical consequence, HFpEF is uniquely intransigent to conventional medical therapies and portends high morbidity and mortality. However, diastolic dysfunction is reversible-as are contributing processes of myocardial fibrosis and myocardial steatosis. Our challenges in preserving myocardial health among PHIV are two-fold. First, we must continue working to realize UNAIDS 90-90-90 goals. This achievement will reduce AIDS-related mortality, including cardiovascular deaths from AIDS-associated heart failure. Second, we must work to elucidate the detailed mechanisms continuing to predispose ART-treated PHIV to heart failure and particularly HFpEF. Such efforts will enable the development and implementation of targeted preventive strategies.

Individualized Protease Inhibitor Monotherapy: The Role of Pharmacokinetics and Pharmacogenetics in an Aged and Heavily Treated HIV-Infected Patient

Antiretroviral therapy has changed the history of HIV infection from a lethal disease to a chronic infection, with the emergence of long-term adverse effects. Herein we present a case of a heavily treated HIV-infected man in whom antiretroviral toxicity had been observed. The lopinavir/ritonavir plasma concentrations at standard doses were significantly above the recommended levels. Pharmacogenetic analysis revealed a polymorphism in the DRD3 gene associated with a decrease in the rate of drug metabolism. Additionally, the patient's low body mass index could have contributed to a greater degree of patient exposure to the drug. After the withdrawal of tenofovir disoproxil and the establishment of individualized protease inhibitor monotherapy at reduced doses, a decrease in the intensity of adverse events was observed, while the clinical outcomes were maintained. The pharmacokinetic-pharmacogenetic analysis was shown to be a tool of huge interest for the management and durability of antiretroviral therapy.

Subcutaneous Adipocyte Adenosine Triphosphate Levels in HIV Infected Patients

Lipoatrophy, or fat wasting, remains a syndrome plaguing HIV⁺ patients receiving antiretroviral (ARV) therapy. Both HIV infection per se and certain ARV are associated with lowered adipose tissue mitochondrial deoxyribonucleic acid (mtDNA) and mitochondrial ribonucleic acid (mtRNA) levels, but effects on adenosine triphosphate (ATP) production are unclear. We hypothesized that such alterations would accompany lowering of ATP levels in fat of HIV⁺ patients and would be worse in those displaying lipoatrophy. Gluteal-fold, subcutaneous adipose tissue was obtained from HIV seronegative control patients, from HIV⁺ ARV-naive patients, and those on ARV with or without lipoatrophy. Cellular ATP was measured in isolated adipocytes and preadipocyte fraction cells by bioluminescence. mtDNA copies/cell and oxidative phosphorylation (OXPHOS) mtRNA transcripts were evaluated by quantitative polymerase chain reactions. ATP levels were consistently higher in preadipocyte fraction cells than adipocytes, but values strongly correlated with each other (r = 0.66, p < .001). ATP levels in adipocytes were higher in both ARV-naive and nonlipoatrophic HIV⁺ patients compared to seronegative controls, but significantly lower in adipocytes and preadipocytes of lipoatrophic versus other HIV⁺ patients. Fat mtDNA copies/cell and OXPHOS mtRNA transcripts were lower in lipoatrophic patient samples compared to HIV seronegative. The ratio of specific OXPHOS transcripts to each other was significantly higher in nonlipoatrophic patients versus all groups, and this ratio correlated significantly with ATP levels in adipocytes. Thus, HIV infection is associated with an increase in adipose tissue ATP stores. Decreases in adipose mtDNA and OXPHOS mtRNA are found in those with HIV on ARV; however, ATP level is effected only in patients displaying lipoatrophy.

Analyses of Mitochondrial DNA and Immune Phenotyping Suggest Accelerated T-Cell Turnover in Treated HIV

BACKGROUND

HIV infection is associated with premature aging, and mitochondrial integrity is compromised during the aging process. Because mitochondrial toxicity is a consequence of antiretroviral therapies (ARTs), we hypothesized HIV and long-term ART would correlate with immunosenescence and mitochondrial DNA (mtDNA) pathology.

SETTING

Thirteen older HIV-infected individuals (aged >40 years) with virologic suppression (stratified by duration of ART) were compared with 10 uninfected controls well-matched for age.

METHODS

Peripheral blood T-cells were immunophenotyped to measure immune activation, proliferation, and immunosenescence in subsets. mtDNA copies per cell and the relative abundance of mtDNA carrying the "common deletion" (RACD) were quantified by droplet digital polymerase chain reaction.

RESULTS

Immune activation was higher in HIV-infected individuals than HIV-uninfected individuals in mature CD4 T-cell subsets (CD4TTM P = 0.025, CD4TEM P = 0.0020) regardless of ART duration. Cell populations from uninfected individuals were more likely to be more senescent populations in mature CD4 T-cell subsets (TTM P = 0.017), and CD8 (CD8TEMRA+ P = 0.0026). No differences were observed in mtDNA or RACD levels in any CD4 T-cell subsets, while CD8TSCM of infected individuals trended to have more mtDNA (P = 0.057) and reduced RACD (P = 0.0025).

CONCLUSIONS

HIV-infected individuals demonstrated increased immune activation, but reduced senescence in more mature T-cell subsets. Increased mtDNA content and lower RACD in CD8TSCM suggest immune activation driven turnover of these cells in HIV-infected persons.

DNA polymerase-γ hypothesis in nucleoside reverse transcriptase-induced mitochondrial toxicity revisited: A potentially protective role for citrus fruit-derived naringenin?

Nucleoside reverse transcriptase inhibitors (NRTIs) form the backbone in combination antiretroviral therapy (cARVs). They halt chain elongation of the viral cDNA by acting as false substrates in counterfeit incorporation mechanism to viral RNA-dependent DNA polymerase. In the process genomic DNA polymerase as well as mitochondrial DNA (mtDNA) polymerase-γ (which has a much higher affinity for these drugs at therapeutic doses) are also impaired. This leads to mitochondrial toxicity that manifests clinically as mitochondrial myopathy, peripheral neuropathy, hyperlactatemia or lactic acidosis and lipoatrophy. This has led to the revision of clinical guidelines by World Health Organization to remove stavudine from first-line listing in the treatment of HIV infections. Recent reports have implicated oxidative stress besides mtDNA polymerase-γ hypothesis in NRTI-induced metabolic complications. Reduced plasma antioxidant concentrations have been reported in HIV positive patients on cARVs but clinical intervention with antioxidant supplements have not been successful either due to low efficacy or poor experimental designs. Citrus fruit-derived naringenin has previously been demonstrated to possess antioxidant and free radical scavenging properties which could prevent mitochondrial toxicity associated with these drugs. This review revisits the controversy surrounding mtDNA polymerase-γ hypothesis and evaluates the potential benefits of naringenin as a potent anti-oxidant and free radical scavenger which as a nutritional supplement or therapeutic adjunct could mitigate the development of mitochondrial toxicity associated with these drugs.

Association Between Health-Related Quality of Life and Physical Functioning in Antiretroviral-Naive HIV-Infected Patients

Background:

Poor functional status can significantly affect Health-Related Quality of Life (HRQoL) of HIV patients. However, there is scarce information on the functional profile of such patients before starting antiretroviral therapy (ART).

Objective:

To estimate the association between health-related quality of life and physical functioning in Antiretroviral-Naive HIV-infected patients.

Methods:

We conducted a cross-sectional study with HIV-infected patients older than 18 years, and naïve to antiretroviral therapy. The patients were evaluated for functional profile by pulmonary function (forced vital capacity, forced expiratory volume at one second, and Tiffeneau index), handgrip strength, and six-minute walk test in a cross-sectional study. HRQoL was evaluated by the 36-Item Short-Form Health Survey and its Physical (PCS) and Mental (MCS) Component Summaries. Multiple linear regression analyses were used to evaluate the association of predictor variables with PCS and MCS scores.

Results:

We found lower HRQoL among females patients, with far below average impairment of mental health component. Both male and female patients presented lower 6MWD function test values. Patients with dynapenia were older than patients without it, presented lower PCS mean score, lower family income, poor 6 MWD function test, lower FVC, and lower FEV1 t. Multivariable logistic regression analyses showed that Grip Strength, age and family income were predictor variables for Physical component of HRQoL. Female gender and smoking habit were predictive for the mental component of HRQoL.

Conclusion:

HRQoL in HIV, drug-naïve patients is predicted by level of dynapenia, smoking, income and gender. Therefore, lifestyle changes and active exercising can help to improve HRQoL in such patients.

Examining Relationships between Metabolism and Persistent Inflammation in HIV Patients on Antiretroviral Therapy

With the advent of antiretroviral therapy (ART), HIV-infected individuals are now living longer and healthier lives. However, ART does not completely restore health and treated individuals are experiencing increased rates of noncommunicable diseases such as dyslipidemia, insulin resistance, type 2 diabetes, cardiovascular disease, and nonalcoholic fatty liver disease. While it is well known that persistent immune activation and inflammation contribute to the development of these comorbid diseases, the mechanisms underlying this chronic activation remain incompletely understood. In this review, we will discuss emerging evidence that suggests that alterations in cellular metabolism may play a central role in driving this immune dysfunction in HIV patients on ART.

Tenofovir-Based Highly Active Antiretroviral Therapy Is Associated with Superior CD4 T Cells Repopulation Compared to Zidovudine-Based HAART in HIV 1 Infected Adults

Tenofovir-based highly active antiretroviral therapy (HAART) is one of the preferred first-line therapies in the management of HIV 1 infection. Ghana has since 2014 adopted this recommendation; however there is paucity of scientific data that reflects the safety and efficacy of the tenofovir-based therapy compared to zidovudine in the Ghanaian health system. This study sought to assess the comparative immune reconstitution potential between tenofovir and zidovudine-based HAART regimens, which includes lamivudine and efavirenz in combination therapy. It also aimed to investigate the adverse drug reactions/events (ADREs) associated with pharmacotherapy with these agents in a total of 106 HAART naïve HIV patients. The study included 80 patients in the tenofovir cohort while 26 patients were on the zidovudine regimen. The occurrence of HIV comorbidities profile was assessed at diagnosis and throughout the study period. The baseline CD4 T cells count of the participants was also assessed at diagnosis and repeated at a median period of five months (range 4–6 months), after commencing treatment with either tenofovir- or zidovudine-based HAART. After five months of the HAART, the tenofovir cohort recorded higher CD4 T cell count change from baseline compared to the zidovudine cohort (p < 0.0001). The patients on the tenofovir-based HAART and female sex however appeared to be associated with more multiple ADREs.

Beneficial and Detrimental Effects of Antiretroviral Therapy on HIV-Associated Immunosenescence

Since the introduction of highly active antiretroviral therapy more than 2 decades ago, HIV-related deaths have dramatically decreased and HIV infection has become a chronic disease. Due to the inability of antiretroviral drugs to eradicate the virus, treatment of HIV infection requires a systemic lifelong therapy. However, even when successfully treated, HIV patients still show increased incidence of age-associated co-morbidities compared with uninfected individuals. Virus- induced immunosenescence, a process characterized by a progressive decline of immune system function, contributes to the premature ageing observed in HIV patients. Although antiretroviral therapy has significantly improved both the quality and length of patient lives, the life expectancy of treated patients is still shorter compared with that of uninfected individuals. In particular, while antiretroviral therapy can contrast some features of HIV-associated immunosenescence, several anti-HIV agents may themselves contribute to other aspects of immune ageing. Moreover, older HIV patients tend to have a worse immunological response to the antiviral therapy. In this review we will examine the available evidence on the role of antiretroviral therapy in the control of the main features regulating immunosenescence.

Changes in liver steatosis evaluated by transient elastography with the controlled attenuation parameter in HIV-infected patients

OBJECTIVES

There are scant data on the progression of hepatic steatosis (HS) in HIV infection. We therefore evaluated changes in HS over time in HIV-infected patients using the controlled attenuation parameter (CAP).

METHODS

A prospective cohort of 326 HIV-infected patients was included in this study. All patients underwent a CAP measurement. Changes in steatosis were evaluated by calculating the median (Q1-Q3) difference between baseline and 12-month CAP values.

RESULTS

The median (Q1-Q3) CAP was 221 (196-252) dB/m at baseline and 224 (198-257) dB/m at the 12-month visit (P = 0.617). Significant steatosis, that is, CAP ≥ 238 dB/m, was observed in 76 individuals (37%) at baseline and in 80 (39%) at the 12-month visit (P = 0.683). The following variables were associated with ΔCAP: plasma HIV RNA [< 50 vs. ≥ 50 HIV-1 RNA copies/mL: median (Q1-Q3) ΔCAP, 4 (-21, 27) vs. -21 (-49, 4) dB/m, respectively; P = 0.024]; body mass index (BMI) [no increase vs. increase: -13 (-40, 4) vs. 14 (-6, 32) dB/m, respectively; P < 0.001]; triglycerides [no increase vs. increase: -1 (-30, 22) vs. 15 (-3, 40) dB/m, respectively; P = 0.001]; fasting plasma glucose [not impaired vs. impaired: -4 (-31, 16) vs. 30 (15, 49) dB/m, respectively; P < 0.001]; and raltegravir [no vs. yes: 5 (-20, 29) vs. -11 (-37.5, 15) dB/m, respectively; P = 0.018]. The only factor independently associated with ΔCAP was BMI [B (standard error): 9.03 (1.9); P < 0.001].

CONCLUSIONS

Increases in CAP values over a period of 12 months in HIV-infected patients were strongly associated with elevations in BMI. Other metabolic factors and antiretroviral drugs were not predictors of CAP changes independent of BMI.

Efficacy and tolerability of switching to a dual therapy with darunavir/ritonavir plus raltegravir in HIV-infected patients with HIV-1 RNA ≤50 cp/mL

BACKGROUND

Nucleos(t)ide reverse transcriptase inhibitors (NRTI) toxicity may represent a threat for long-term success of combined antiretroviral therapy. Some studies have suggested a possible improvement of NRTI-related toxicity after switching to NRTI-sparing regimens.

OBJECTIVES

We aimed to explore the efficacy and tolerability of switching to darunavir/ritonavir (DRV/r) plus raltegravir (RAL) while having a viral load (VL) ≤50 copies/mL in the clinical setting.

STUDY DESIGN

Treatment-experienced HIV 1-infected patients enrolled in the ICONA Foundation Study cohort were included if they switched their current regimen to DRV/r + RAL with a HIV-RNA ≤50 copies/mL. Different definitions of virological failure (VF) and treatment failure (TF) were employed. Kaplan-Meier curves and Cox regression models were performed to estimate time to event probability.

RESULTS

We included 72 HIV-infected patients, 22 (31%) of these were female, 31 (43%) men who have sex with men (MSM) amd 15 (21%) had hepatitis co-infections. Median age was 44 (IQR: 35-50) years amd CD4 count was 389 (IQR 283-606) cells/mmc. Median follow-up time for TF was 24 (IQR 9-31) months. Twenty-five discontinuations occurred (60% simplifications); only 2 (8%) were toxicity-driven (lipid elevations). The probability of VF (confirmed VL >50 copies/mL) was estimated at 7% [95% confidence interval (CI) 1-13%] by 12 and 9% (95% CI 2-16%) by 24 months. When considering TF, we found a probability of stop/intensification/single VL > 200 copies/mL of 13% (95% CI 1-17%) and 22% (95% CI 11-33%) by 12 and 24 months. Female gender (adjusted relative hazard, ARH = 0.10; 95% CI 0.01-0.74; p = 0.024) and older age (AHR = 0.50 per 10 years older; 95% CI 0.25-0.99; p = 0.045) were associated with a lower risk of TF. A previous PI failure was strongly associated with TF (AHR = 52.6, 95% CI 3.6-779; p = 0.004).

CONCLUSIONS

DRV/r + RAL is a valuable NRTI-sparing option, especially in female and older patients, with a relatively low risk of VF and good tolerability after 2 years since start in an ART-experienced population. However, previous PI-failure should be a limiting factor for this strategy.

Mitochondrial toxicity and caspase activation in HIV pregnant women

To assess the impact of HIV-infection and highly active anti-retroviral treatment in mitochondria and apoptotic activation of caspases during pregnancy and their association with adverse perinatal outcome. Changes of mitochondrial parameters and apoptotic caspase activation in maternal peripheral blood mononuclear cells were compared at first trimester of pregnancy and delivery in 27 HIV-infected and -treated pregnant women versus 24 uninfected pregnant controls. We correlated immunovirological, therapeutic and perinatal outcome with experimental findings: mitochondrial DNA (mtDNA) content, mitochondrial protein synthesis, mitochondrial function and apoptotic caspase activation. The HIV pregnancies showed increased adverse perinatal outcome (OR: 4.81 [1.14-20.16]; P < 0.05) and decreased mtDNA content (42.66 ± 5.94%, P < 0.01) compared to controls, even higher in naïve participants. This depletion caused a correlated decrease in mitochondrial protein synthesis (12.82 ± 5.73%, P < 0.01) and function (20.50 ± 10.14%, P < 0.001), not observed in controls. Along pregnancy, apoptotic caspase-3 activation increased 63.64 ± 45.45% in controls (P < 0.001) and 100.00 ± 47.37% in HIV-pregnancies (P < 0.001), in correlation with longer exposure to nucleoside analogues. HIV-infected women showed increased obstetric problems and declined genetic and functional mitochondrial parameters during pregnancy, especially those firstly exposed to anti-retrovirals. The apoptotic activation of caspases along pregnancy is emphasized in HIV pregnancies promoted by nucleoside analogues. However, we could not demonstrate direct mitochondrial or apoptotic implication in adverse obstetric outcome probably because of the reduced sample size.

Frailty in HIV: Epidemiology, Biology, Measurement, Interventions, and Research Needs

Frailty is a critical aging-related syndrome marked by diminished physiologic reserve and heightened vulnerability to stressors, predisposing to major adverse clinical outcomes, including hospitalization, institutionalization, disability, and death in the general population of older adults. As the proportion of older adults living with HIV increases in the era of antiretroviral therapy, frailty is increasingly recognized to be of significant clinical and public health relevance to the HIV-infected population. This article reviews current knowledge on the epidemiology and biology of frailty and its potential role as a target for reducing disparities in outcomes in HIV; conceptual frameworks and current approaches to frailty measurement; existing data on frailty interventions; and important areas for future research focus necessary to develop and advance effective strategies to prevent or ameliorate frailty and its marked adverse consequences among people living with HIV.

Immunovirological Efficacy of Once-Daily Maraviroc Plus Ritonavir-Boosted Atazanavir After 48 Weeks in Naive HIV-Infected Patients

Toxicities related to the use of nucleoside analogues have increased the interest in developing nucleoside-sparing regimens, mainly combining protease inhibitors with raltegravir. However, data regarding the use of CCR5-antagonists in this setting and in the naive scenario are scarce. The main objective was to analyze the immunovirological efficacy and tolerability of a low-dose, once-daily, maraviroc (MVC)-containing, nucleoside reverse transcriptase inhibitor-sparing dual therapy compared with standard triple therapy after 48 weeks for naive HIV-infected patients in the routine clinical practice setting. All naive HIV-infected patients with stable clinical condition that started antiretroviral treatment since February 1, 2008 to May 30,h 2012 were included. MVC clinical test was used to select candidate subjects to MVC therapy. Thirty-two subjects with MVC + atazanavir/ritonavir (ATV/r) and 66 with standard triple therapy were analyzed. A comparable virological efficacy between groups was found after 48 weeks (87.5% vs. 80.3% of HIV undetectability, p = 0.37, MVC + ATV/r and triple therapy groups, respectively). The CD4 recovery after 48 weeks was similar and more than 200 cells/mm³ in both groups. No need of therapy changes or treatment discontinuations was observed in the MVC + ATV/r group. Effect on lipid profile, high-sensitivity C reactive protein, and β2-microglobulin was similar for both groups. Noteworthy, a significant increase of erythrocyte mean corpuscular volume was observed only in the triple therapy group. A nucleoside-sparing MVC-containing dual therapy showed similar immunovirological efficacy and tolerability than standard triple therapy in naive HIV-infected patients.

Plasma Mitochondrial DNA Levels as a Biomarker of Lipodystrophy Among HIV-infected Patients Treated with Highly Active Antiretroviral Therapy (HAART)

Lipodystrophy is a common complication in HIV-infected patients taking highly active antiretroviral therapy. Its early diagnosis is crucial for timely modification of antiretroviral therapy. We hypothesize that mitochondrial DNA in plasma may be a potential marker of LD in HIV-infected individuals. In this study, we compared plasma mitochondrial DNA levels in HIV-infected individuals and non-HIV-infected individuals to investigate its potential diagnostic value. Total plasma DNA was extracted from 67 HIV-infected patients at baseline and 12, 24 and 30 months after initiating antiretroviral therapy. Real-time quantitative PCR was used to determine the mitochondrial DNA levels in plasma. Lipodystrophy was defined by the physician-assessed presence of lipoatrophy or lipohypertrophy in one or more body regions. The mitochondrial DNA levels in plasma were significantly higher at baseline in HIV-infected individuals than in non-HIV-infected individuals (p<0.05). At month 30, 33 out of 67 patients (49.2%) showed at least one sign of lipodystrophy. The mean plasma mitochondrial DNA levels in lipodystrophy patients were significantly higher compared to those without lipodystrophy at month 24 (p<0.001). The receiver operating curve analysis demonstrated that using plasma mitochondrial DNA level (with cut-off value <5.09 log10 copies/ml) as a molecular marker allowed identification of patients with lipodystrophy with a sensitivity of 64.2% and a specificity of 73.0%. Our data suggest that mitochondrial DNA levels may help to guide therapy selection with regards to HIV lipodystrophy risk.

Oxidative mitochondrial DNA damage in peripheral blood mononuclear cells is associated with reduced volumes of hippocampus and subcortical gray matter in chronically HIV-infected patients

Cross-sectional relationships were examined between regional brain volumes and mitochondrial DNA (mtDNA) 8-hydroxy-2-deoxyguanosine (8-oxo-dG) in peripheral blood mononuclear cells (PBMCs) of 47 HIV patients [mean age 51years; 81% with HIV RNA ≤50copies/mL] on combination antiretroviral therapy. The gene-specific DNA damage and repair assay measured mtDNA 8-oxo-dG break frequency. Magnetic resonance imaging was performed at 3T. Higher mtDNA 8-oxo-dG was associated with lateral ventricular enlargement and with decreased volumes of hippocampus, pallidum, and total subcortical gray matter, suggesting the involvement of systemic mitochondrial-specific oxidative stress in chronic HIV-related structural brain changes and cognitive difficulties. Clarification of the mechanism may provide potential therapeutic targets.

Antiviral activity of genital tract secretions after oral or topical tenofovir pre-exposure prophylaxis for HIV-1

BACKGROUND

Surrogate markers of HIV-1 pre-exposure prophylaxis and microbicide efficacy are needed. One potential surrogate is the antiviral activity in cervicovaginal lavage (CVL) after exposure to candidate products. We measured CVL antiviral activity in women using oral or vaginal tenofovir-based pre-exposure prophylaxis and correlated activity with drug and immune mediator levels.

METHODS

Inhibitory activity against HIV-1 and herpes simplex virus (HSV)-2 and concentrations of interleukin (IL)-1β, IL-6, IL-8, interferon-γ, induced protein 10 (IP-10), macrophage inflammatory protein (MIP)-1α, MIP-3a, lactoferrin, secretory leukocyte protease inhibitor, and defensins were measured in CVL obtained from 60 women at baseline and after 6 weeks of a randomized sequence of oral and topical tenofovir. CVL tenofovir concentrations were measured by mass spectrometry.

RESULTS

The number of women with CVL anti-HIV activity ≥ 90% increased significantly from 5.0% at baseline to 89.1% after daily use of 1% tenofovir gel (relative risk = 17.85, P < 0.001), but there was no increase after daily oral tenofovir. The CVL anti-HIV activity correlated with drug levels (Spearman correlation coefficient 0.64 after tenofovir gel; P < 0.001) but not with the concentrations of mucosal immune mediators. No increase in CVL anti-HSV activity was observed after either drug regimen, an observation consistent with the higher concentrations of tenofovir needed to inhibit HSV-2 infection. The CVL anti-HSV activity correlated with lactoferrin, defensins, IP-10, IL-8, and detectable levels of MIP-1α but not with drug levels.

CONCLUSIONS

CVL may provide a surrogate for local but not systemic drug efficacy and a tool to better understand mucosal factors that modulate antiviral activity in genital tract secretions.

Prevalence and factors associated with liver steatosis as measured by transient elastography with controlled attenuation parameter in HIV-infected patients

OBJECTIVE

To assess the prevalence and factors associated with significant hepatic steatosis (SHS, steatosis involving ≥10% hepatocytes) in HIV-infected patients.

DESIGN

A prospective, cross-sectional study.

METHODS

Five hundred and five HIV-infected patients were included in this study. All patients underwent a transient elastography examination with the controlled attenuation parameter (CAP). SHS was defined using the previously identified CAP cut-off of 238 dB/m. We analysed the associations between SHS and demographics, metabolic data, coinfections and drug therapy.

RESULTS

SHS was detected in 201 (40%) patients. Individuals with and without plasma HIV RNA of 50 copies/ml or less presented SHS in 168 (42%) and 33 (31%) cases, respectively (P = 0.030). Patients with SHS compared with those without SHS presented higher median (IQR) BMI [BMI, 25.6 (22.5-28) vs. 22.3 (20.3-24.2) kg/m; P < 10], DBP [79 (72-85) vs. 74 (68-81) mmHg; P = 0.0001], fasting plasma glucose [95 (87-106) vs. 91 (84-97) mg/dl; P = 0.002] and triglycerides [128 (92-189) vs. 109 (80-167) mg/dl; P = 0.002], and lower HDL cholesterol [44 (37-54) vs. 48 (40-59), mg/dl; P = 0.004]. In multivariate analysis, the only factor associated with SHS was BMI [per unit increase, adjusted odds ratio (95% confidence interval) 1.34 (1.22-1-47); P < 10].

CONCLUSION

SHS measured by CAP is highly prevalent among HIV-infected patients. High BMI is the main predictor of SHS in this setting.

Role of mitochondria in HIV infection and associated metabolic disorders: focus on nonalcoholic fatty liver disease and lipodystrophy syndrome

Highly active antiretroviral therapy (HAART) has considerably improved the prognosis of HIV-infected patients. However, prolonged use of HAART has been related to long-term adverse events that can compromise patient health such as HIV-associated lipodystrophy syndrome (HALS) and nonalcoholic fatty liver disease (NAFLD). There is consistent evidence for a central role of mitochondrial dysfunction in these pathologies. Nucleotide reverse transcriptase inhibitors (NRTIs) have been described to be mainly responsible for mitochondrial dysfunction in adipose tissue and liver although nonnucleoside transcriptase inhibitors (NNRTIs) or protease inhibitors (PIs) have also showed mitochondrial toxicity, which is a major concern for the selection and the long-term adherence to a particular therapy. Several mechanisms explain these deleterious effects of HAART on mitochondria, and evidence points to other mechanisms beyond the “Pol-γ hypothesis.” HIV infection has also direct effects on mitochondria. In addition to the negative effects described for HIV itself and/or HAART on mitochondria, HIV-infected patients are more prone to develop a premature aging and, therefore, to present an increased oxidative state that could lead to the development of these metabolic disturbances observed in HIV-infected patients.

European mitochondrial haplogroups are associated with CD4+ T cell recovery in HIV-infected patients on combination antiretroviral therapy

BACKGROUND

There is substantial interindividual variability in the rate and extent of CD4+ T cell recovery after starting combination antiretroviral therapy (cART). The aim of our study was to determine whether mitochondrial DNA (mtDNA) haplogroups are associated with recovery of CD4+ in HIV-infected patients on cART.

METHODS

We carried out a retrospective study on 275 cART-naive patients with CD4+ counts <350 cells/mm(3), who were followed-up during at least 24 months after initiating cART. mtDNA genotyping was performed by Sequenom's MassARRAY platform.

RESULTS

Patients within cluster JT and haplogroup J had a lower chance of achieving a CD4+ count ≥500 cells/mm(3) than patients within cluster HV and haplogroup H [hazard ratio (HR) = 0.68 (P = 0.058) and HR = 0.48 (P = 0.010), respectively]. The time of follow-up during which the CD4+ count was ≥500 cells/mm(3) was longer in haplogroups HV and H than in haplogroups JT and J [20 months versus 6.2 months (P = 0.029) and 20 months versus 0 months (P = 0.024), respectively]. Additionally, haplogroups HV and H had greater chances of achieving a CD4+ count ≥500 cells/mm(3) during at least 12, 36, 48 and 60 months post-cART initiation compared with patients within haplogroups JT and J. Patients within haplogroup T only had a lesser chance of achieving a CD4+ count ≥500 cells/mm(3) during at least 48 months and 60 months post-cART initiation.

CONCLUSION

European mitochondrial haplogroups might influence CD4+ recovery in HIV-infected patients following initiation with cART. Haplogroups J and T appear to be associated with a worse profile of CD4+ recovery, whereas haplogroup H was associated with a better CD4+ reconstitution.

Impact of age on markers of HIV-1 disease

Aging is a complicated process characterized by a progressive loss of homeostasis, which results in an increased vulnerability to multiple diseases. HIV-1-infected patients demonstrate a premature aging phenotype and develop certain age-related diseases earlier in their lifespan than what is seen in the general population. Age-related comorbidities may include the development of bone disease, metabolic disorders, neurologic impairment and immunosenescence. Age also appears to have an effect on traditional markers of HIV-1 disease progression, including CD4+ T-cell count and viral load. These effects are not only a consequence of HIV-1 infection, but in many cases, are also linked to antiretroviral therapy. This review summarizes the complex interplay between HIV-1 infection and aging, and the impact that aging has on markers of HIV-1 disease.

Hepatic steatosis and steatohepatitis in human immunodeficiency virus/hepatitis C virus-coinfected patients

Hepatic steatosis (HS) is frequent in human immunodeficiency virus (HIV)- and hepatitis C virus (HCV)-coinfected patients. Antiretroviral therapy (ART) and metabolic alterations could induce HS. However, a protective effect of ART has been reported in a paired biopsy study. Thus, our aim was to examine the changes and predictors of HS progression among HIV/HCV-coinfected patients with sequential biopsies. We also evaluated the rates of steatohepatitis and factors associated thereof. HIV-infected patients with detectable serum HCV RNA, who underwent two biopsies, separated at least by 1 year, were included in this retrospective study. HS progression was defined as increase in one or more HS grades. The median (interquartile range) time between biopsies was 3.3 (2.0-5.2) years. Among 146 individuals, HS at baseline was observed in 86 (60%) patients and in 113 (77%) in the follow-up biopsy (P < 0.001). Progression of HS was observed in 60 (40%) patients. HS regressed in 11 (8%) patients. Factors associated with HS progression were changes in fasting plasma glucose (FPG) between biopsies (per 10 mg/dL increase; odds ratio [OR] [95% confidence interval; CI] = 1.4 [1.04-1.8]; P = 0.024) and cumulative use of dideoxynucleoside analogs (per year; OR [95% CI] = 1.5 [1.2-1.8]; P = 0.001). Persistent steatohepatitis or progression to steatohepatitis between biopsies was observed in 27 (18%) patients. Persistence of or progression to steatohepatitis was associated with progression ≥ 1 fibrosis stages between biopsies (OR [95% CI] = 2.4 [1.01-5.7]; P = 0.047).

CONCLUSIONS

HS progresses frequently and regression is rarely observed in HIV/HCV-coinfected patients, including in those on ART. Cumulative exposure to dideoxynucleoside analogs and increases in FPG are related with HS progression. Stetatohepatitis is frequently observed in these patients and is linked to fibrosis progression.

HIV-1 infection and first line ART induced differential responses in mitochondria from blood lymphocytes and monocytes: the ANRS EP45 "Aging" study

BACKGROUND

The ANRS EP45 "Aging" study investigates the cellular mechanisms involved in the accelerated aging of HIV-1 infected and treated patients. The data reported focus on mitochondria, organelles known to be involved in cell senescence.

METHODS

49 HIV-1 infected patients untreated with antiretroviral therapy, together with 49 seronegative age- and sex-matched control subjects and 81 HIV-1 infected and treated patients, were recruited by 3 AIDS centres (Marseille, Montpellier, Nice; France; http://clinicaltrials.gov/, NCT01038999). In more than 88% of treated patients, the viral load was <40 copies/ml and the CD4+ cell count was >500/mm(3). ROS (reactive oxygen species) production and ΔΨm (inner membrane potential) were measured by flow cytometry in blood lymphocytes and monocytes (functional parameters). Three mitochondrial network quantitative morphological parameters were computed using confocal microscopy and image analysis. Three PBMC mitochondrial proteins (porin and subunits 2 and 4 of cytochrome C oxidase encoded by mtDNA or nuclear DNA, respectively) were analysed by western blotting.

RESULTS

Quantitative changes in PBMC mitochondrial proteins were not induced by either HIV-1 infection or ART. Discriminant analysis integrating functional (ROS production and ΔΨm) or morphological (network volume density, fragmentation and branching) parameters revealed HIV-1 infection and ART differential effects according to cell type. First line ART tended to rescue lymphocyte mitochondrial parameters altered by viral infection, but induced slight changes in monocytes. No statistical difference was found between the effects of three ART regimens on mitochondrial parameters. Correlations between functional parameters and viral load confirmed the damaging effects of HIV-1 in lymphocyte mitochondria.

CONCLUSIONS

In patients considered to be clinically stable, mitochondria exhibited functional and morphological modifications in PBMCs resulting from either direct or indirect effects of HIV-1 infection (lymphocytes), or from first line ART (monocytes). Together with other tissue impairments, these changes may contribute to global aging.

Antiretroviral neurotoxicity

Combination antiretroviral therapy (CART) has proven to effectively suppress systemic HIV burden, however, poor penetration into the central nervous system (CNS) provides incomplete protection. Although the severity of HIV-associated neurocognitive disorders (HAND) has been reduced, neurological disease is expected to exert an increasing burden as HIV-infected patients live longer. Strategies to enhance penetration of antiretroviral compounds into the CNS could help to control HIV replication in this reservoir but also carries an increased risk of neurotoxicity. Efforts to target antiretroviral compounds to the CNS will have to balance these risks against the potential gain. Unfortunately, little information is available on the actions of antiretroviral compounds in the CNS, particularly at concentrations that provide effective virus suppression. The current studies evaluated the direct effects of 15 antiretroviral compounds on neurons to begin to provide basic neurotoxicity data that will serve as a foundation for the development of dosing and drug selection guidelines. Using sensitive indices of neural damage, we found a wide range of toxicities, with median toxic concentrations ranging from 2 to 10,000 ng/ml. Some toxic concentrations overlapped concentrations currently seen in the CSF but the level of toxicity was generally modest at clinically relevant concentrations. Highest neurotoxicities were associated with abacavir, efavarenz, etravirine, nevaripine, and atazanavir, while the lowest were with darunavir, emtracitabine, tenofovir, and maraviroc. No additive effects were seen with combinations used clinically. These data provide initial evidence useful for the development of treatment strategies that might reduce the risk of antiretroviral neurotoxicity.

Safety of tenofovir use during pregnancy: early growth outcomes in HIV-exposed uninfected infants

OBJECTIVE

To evaluate the association of tenofovir disoproxil fumarate (TDF) use during pregnancy with early growth parameters in HIV-exposed, uninfected (HEU) infants.

DESIGN

US-based prospective cohort study of HEU children to examine potential adverse effects of prenatal TDF exposure.

METHODS

We evaluated the association of maternal TDF use during pregnancy with small for gestational age (SGA); low birth weight (LBW, <2.5 kg); weight-for-age z-scores (WAZ), length-for-age z-scores (LAZ), and head circumference-for-age (HCAZ) z-scores at newborn visit; and LAZ, HCAZ, and WAZ at age 1 year. Logistic regression models for LBW and SGA were fit, adjusting for maternal and sociodemographic factors. Adjusted linear regression models were used to evaluate LAZ, WAZ, and HCAZ by TDF exposure.

RESULTS

Of 2029 enrolled children with maternal antiretroviral information, TDF was used by 449 (21%) HIV-infected mothers, increasing from 14% in 2003 to 43% in 2010. There was no difference between those exposed to combination regimens with vs. without TDF for SGA, LBW, and newborn LAZ and HCAZ. However, at age 1 year, infants exposed to combination regimens with TDF had significantly lower adjusted mean LAZ and HCAZ than those without TDF (LAZ: -0.17 vs. -0.03, P=0.04; HCAZ: 0.17 vs. 0.42, P=0.02).

CONCLUSION

TDF use during pregnancy was not associated with increased risk for LBW or SGA. The slightly lower mean LAZ and HCAZ observed at age 1 year in TDF-exposed infants are of uncertain significance but underscore the need for additional studies of growth outcomes after TDF use during pregnancy.

Association between retinal nerve fiber layer thickness and abnormalities of vision in people with human immunodeficiency virus infection

PURPOSE

To investigate relationships between contrast sensitivity (CS), color vision, and retinal nerve fiber layer (RNFL) among people with human immunodeficiency virus (HIV) infection; to evaluate the effect of time since diagnosis of HIV infection on RNFL thickness.

DESIGN

Noninterventional cross-sectional study.

METHODS

We evaluated 102 eyes of 57 HIV-infected individuals without ocular opportunistic infections. Peripapillary RNFL thickness was determined with spectral-domain optical coherence tomography in 4 quadrants. CS was measured with the Pelli-Robson technique (expressed as logCS); color vision was measured with the Lanthony desaturated 15-hue technique (expressed as color confusion index [C-index], with higher scores indicating worse color vision). Correlations between values were assessed using Spearman correlation coefficients.

RESULTS

Median RNFL thickness (average of 4 quadrants) was 102.9 μm (range, 75.0-134.7 μm). Median logCS was 1.90 (range, 1.25-1.95). Median C-index was 1.58 (range, 0.96-4.07). Temporal RNFL thickness was correlated with logCS (r=0.295, P=.003) and C-index (r=-0.338, P=.0005). Time since diagnosis of HIV infection was shorter for those with thick average RNFL than for those with thin average RNFL (P=.18).

CONCLUSIONS

Both worse CS and worse color vision are correlated with thinning of the temporal RNFL, with possible threshold effects. Increased prevalences of abnormal CS and abnormal color vision in this population are therefore likely attributable to neuroretinal compromise. This pattern of structural and functional losses may reflect preferential damage to small-caliber axons in the maculopapillary bundle, possibly associated with mitochondrial dysfunction, providing a potential disease mechanism for HIV-associated "neuroretinal disorder."

Dyslipidemia in HIV-infected individuals

Metabolic complications continue to play a major role in the management of HIV infection. Dyslipidemia associated with HIV infection and with the use of combined antiretroviral therapy includes elevations in triglycerides, reduced high-density cholesterol, and variable increases in low-density and total cholesterol. The association between dyslipidemia and specific antiretroviral agents has been underscored. Multiple pathogenic mechanisms by which HIV and antiretroviral agents lead to dyslipidemia have been hypothesized, but they are still controversial. The potential clinical and pathological consequences of HIV-associated hyperlipidemia are not completely known, but several studies reported an increased risk of coronary artery disease in HIV-positive individuals receiving combined antiretroviral therapy. HIV-infected persons who have hyperlipidemia should be managed similarly to those without HIV infection in accordance with the National Cholesterol Education Program. Life style changes are the primary target. Statins and fibrates and/or modification in antiretroviral therapy are possible approaches to this problem.

European mitochondrial DNA haplogroups and liver fibrosis in HIV and hepatitis C virus coinfected patients

BACKGROUND

HIV infection, hepatitis C virus (HCV) liver disease, and mitochondrial DNA (mtDNA) polymorphisms are three possibly interrelated factors that might be associated with progression of liver disease. The aim of this study was to investigate whether mtDNA haplogroups had any influence on liver fibrosis progression in HIV/HCV coinfected patients.

METHODS

We carried out a cross-sectional study in 231 patients who were genotyped via Sequenom's MassARRAY platform (San Diego, California, USA). Liver fibrosis was estimated based on the METAVIR score. In each patient, fibrosis progression rate (FPR) was calculated by dividing the fibrosis stage (0-4) by the estimated duration of HCV infection in years.

RESULTS

The cluster or major haplogroup HV was significantly associated with reduced odds ratios (OR) for advanced fibrosis [OR 0.35, 95% confidence interval (CI) 0.16-0.77, P = 0.009], cirrhosis (OR 0.16, 95% CI 0.04-0.60, P = 0.007), or high FPR (OR 0.43, 95% CI 0.21-0.84, P = 0.015). Within the major haplogroup HV, haplogroup H was significantly associated with an absence of advanced fibrosis (OR 0.40, 95% CI 0.18-0.91, P = 0.029), cirrhosis (OR 0.14, 95% CI 0.03-0.67, P = 0.014), or high FPR (OR 0.47, 95% CI 0.23-0.95, P = 0.035). We also found a significant association with increased odds of cirrhosis (OR 5.25, 95% CI 1.76-15.64, P = 0.003) in the closely related major haplogroup U.

CONCLUSION

The mtDNA haplogroups HV and H were associated with slower fibrosis progression, and the haplogroup U was associated with faster fibrosis progression in HIV/HCV coinfected patients. These data suggest that mtDNA haplogroup may play a significant role in liver fibrogenesis during HCV infection.

Molecular mechanisms for insulin resistance in treated HIV-infection

Identification and characterization of the molecular mechanisms contributing to the high incidence of insulin resistance in HIV infected patients treated with combined antiretroviral therapy remains a critically important goal in the quest to improve the safety of antiretroviral treatment regimens. The use of in vitro model systems together with the investigation of drug-mediated effects on glucose homeostasis in animals and healthy human volunteers has provided important insight into the contribution of individual drugs to insulin resistance and affected cellular pathways. HIV protease inhibitor mediated blockade of glucose transport and nucleoside reverse transcriptase inhibitor mediated mitochondrial toxicity have been well characterized. Together with growing understanding of mediators of insulin resistance in non-HIV metabolic syndrome, additional cellular effects including the induction of endoplasmic reticulum and oxidative stress, altered adipocytokine secretion, and lipotoxicity have been integrated into this developing picture. Further elucidation of these mechanisms provides potential for the continued development of safer antiviral drugs and targeted treatment of insulin resistance in affected patients.

Mitochondrial abnormalities in patients with HIV-HCV co-infection as compared to patients with HCV mono-infection

INTRODUCTION

Mitochondrial dysfunction is a classic complication of HIV infection and its treatment and has also been reported in hepatitis C virus (HCV)-infected patients. Little is known about interactions between both viruses on mitochondrial metabolism.

METHODS

We performed a cross-sectional study of HCV-infected patients who underwent liver biopsy as part of their routine care. Mitochondrial function was assessed by (a) liver morphological (histology) and functional (spectro-photometry) studies, and (b) serum lactate kinetics, oxygen uptake, and anaerobic threshold measurement during standardized incremental exercise. Three predefined groups of patients were compared.

RESULTS

Thirty-eight HCV-infected patients were included: 13 not HIV infected (group 1), 7 with HIV co-infection and low nucleoside reverse transcriptase inhibitor (NRTI) exposure (none over the last 2 years; group 2), and 18 with HIV co-infection and high NRTI exposure (group 3). On liver biopsies, respiratory chain complex IV activity was impaired, at 5 (2-7) nmol/min/mg substrates in group 1, 5 (3-8) in group 2, and 8 (2-13) in group 3 (normal values, 20-56). Maximal power output was diminished and anaerobic threshold occurred earlier in HIV-infected patients, regardless of NRTI exposure.

CONCLUSION

HCV has deleterious effects on liver mitochondrial metabolism, notably on respiratory chain complex IV. No significant interaction with HIV was observed.

Pharmacological considerations for tenofovir and emtricitabine to prevent HIV infection

The use of antiretroviral medications in HIV-negative individuals as pre-exposure prophylaxis (PrEP) is a promising approach to prevent HIV infection. Tenofovir disoproxil fumarate (TDF) and emtricitabine exhibit desirable properties for PrEP including: favourable pharmacokinetics that support infrequent dosing; few major drug-drug or drug-food interactions; an excellent clinical safety record; and pre-clinical evidence for efficacy. Several large, randomized, controlled clinical trials are evaluating the safety and efficacy of TDF and emtricitabine for this new indication. A thorough understanding of variability in drug response will help determine future investigations in the field and/or implementation into clinical care. Because tenofovir and emtricitabine are nucleos(t)ide analogues, the HIV prevention and toxicity effects depend on the triphosphate analogue formed intracellularly. This review identifies important cellular pharmacology considerations for tenofovir and emtricitabine, which include drug penetration into relevant tissues and cell types, race/ethnicity/pharmacogenetics, gender, cellular activation state and appropriate episodic or alternative dosing strategies based on pharmacokinetic principles. The current state of knowledge in these areas is summarized and the future utility of intracellular pharmacokinetics/pharmacodynamics for the PrEP field is discussed.