Current HIV Research - Volume 8, Issue 5, 2010

The ability to detect HIV-1 in tissues that are not readily amenable to biopsy greatly limits the diagnosis and control of HIV infection, and ultimately, our ability to understand HIV-induced disease pathology. In view of this, we explored the utility of diagnostically measuring HIV-1 infection using 31P nuclear magnetic resonance (31P-NMR). 31PNMR enables the correlation of infection to changes in the concentration of specific intracellular metabolites, macromolecules and of bioenergetic parameters that are key to mammalian cell physiology. Examples include primary components of biological membranes such as phosphomonoester (PME) and phosphodiester (PDE) lipids. Using 31PNMR we found that changes in the ratio of PDE/PME in human cell lines and primary isolates were significantly altered following HIV-1 infection. Our findings showed that the ratio of cellular PDE/PME uniformly decreased 2.00 - 2.26 fold in HIV-1infected cells. Using the altered PDE/PME ratio as a selection criterion, we next assessed HIV-1 infection in lymphocytes isolated from both HIV-1 seropositive and non-infected human subjects. A decreased PDE/PME ratio was characteristic of HIV-1 infection in each instance. These results demonstrate that changes in cellular phospholipids induced during HIV-1 infection may be used to uncover basic mechanisms of HIV-1 pathology, and potentially, may be extrapolated to explore the application of NMR analysis as a technique for imaging infected organs and tissues in situ.

The aim of this study was to describe the status of oxidative stress and antioxidant biomarkers and their association with metabolic and body composition components of HIV-lipodystrophy syndrome. In a cross-sectional study of blood samples from HIV-infected men with lipodystrophy syndrome (HIV+LIPO+ = 10), HIV-infected men without lipodystrophy syndrome (HIV+LIPO- = 22), and healthy subjects (control = 12), the following oxidative stress biomarkers were analyzed: total hydroperoxide, thiobarbituric acid reactive substances (TBARS), and advanced oxidation protein products (AOPP). In addition, antioxidant biomarkers, including total glutathione, uric acid, α-tocopherol, and metabolic components were tested. Dual-energy x-ray absorciometry (DXA) was used to measure the fat mass. The duration of HIV infection and the duration and type of highly active antiretroviral therapy were similar between the two HIV-infected groups. Higher levels of total hydroperoxide were observed in the HIV+LIPO+ (50 ± 33 H2O2/L) group compared to the HIV+LIPO- (19 ± 13 H2O2/L) and control (5 ± 5 H2O2/L) groups (p < 0.05). Similarly, higher levels of AOPP were observed in the HIV+LIPO+ (326 ± 173 μmol/L) group compared to the HIV+LIPO- (105 ± 92 μmol/L) and control groups (80 ± 20 μmol/L) (p < 0.05). Total hydroperoxide significantly correlated with insulin serum levels in the HIV+LIPO+ (r = 0.47, p < 0.05) and HIV+LIPO- groups (r = 0.29, p < 0.05), while AOPP significantly correlated with insulin serum levels in the HIV+LIPO+ (r = 0.73, p < 0.05) and HIV+LIPO- (r = 0.54, p < 0.05) groups. Therefore, higher lipid and protein oxidation were found in HIV-infected patients with lipodystrophy syndrome, and both were associated with insulin levels.

Objective: Community-based antiretroviral treatment (CBART) programs should aim to achieve positive quality of life outcomes. The purpose of this study was to investigate changes in the health related quality of life (HRQOL) outcomes of patients in a CBART program supported by community volunteers in one sub-county in western Uganda located 50 km from the nearest urban centre. Methods: We administered a translated version of the MOS-HIV survey and collected clinical data at baseline and after one year from 130 patients. Inclusion criteria included residency in the sub-county, eighteen years of age or, treatmentnaive, eligible for ART based on CD4 cell count <200 cells/mm3 or WHO clinical stage 3 or 4, and willing to accept daily treatment support by family/friends and to be visited by a community volunteer weekly. We assessed changes in physical health (PHS) and mental health (MHS) summary scores and examined associations between patient characteristics and changes in HRQOL. Results: After one year, we observed significant increases in mean PHS (42.7 to 50.1; p<0.01) and MHS (43.5 to 49.5; p<0.01) scores. Lower age (p<0.01) and lower baseline PHS scores (p<0.01) were associated with increases in PHS scores and lower age (p=0.03) and lower baseline MHS scores (p<0.01) were associated with increases in MHS scores. Fifteen patients (12%) had reductions in their HRQOL after one year which were not associated with patient or clinical characteristics, including virological suppression. Conclusions: The observed improvements in HRQOL demonstrate that positive treatment outcomes can be achieved in CBART programs in rural Uganda. However, some patients appear to experience declines in their overall well-being, despite achieving virological suppression. HRQOL surveys can be useful in identifying these patients, who may require additional attention and support to achieve the full benefits of ART.

Objective: The ability of a prolonged antiretroviral treatment interruption to reverse mitochondrial toxicity was evaluated in a sub-study of TIBET, a prospective trial examining antiretroviral treatment interruption guided by CD4+ cell count. Patients and Methods: The study population was composed of patients from the TIBET study who had been followed for ≥96 weeks and whose peripheral blood mononuclear cells (PBMCs) had been collected at baseline and throughout the study period. Of the 201 patients included in the TIBET study, 38 were selected for the mitochondrial sub-study; 18 patients discontinued antiretroviral therapy for ≥96 weeks and 20 maintained therapy. Mitochondrial DNA (mtDNA) and RNA (mtRNA) were measured in PBMCs using real-time polymerase chain reaction, and mitochondrial function relative to mitochondrial content was assessed using the cytochrome c oxidase and citrate synthase ratio (COX/CS). Results: Whereas mtDNA content showed a similar progressive decrease throughout the study period in both arms, the mtRNA amount remained stable in both groups and the COX/CS ratio improved significantly in patients who interrupted therapy. Conclusions: Mitochondrial function improved during a prolonged antiretroviral treatment interruption despite a decrease in mtDNA levels in PBMCs, probably because of the existence of a mitochondrial transcriptional and translational upregulation mechanism or the reversion of mitochondrial toxicity by a mechanism that is independent of DNA polymerase gamma. The reduction in virus-related mitochondrial damage should be considered another relevant benefit of antiretroviral therapy.

Introduction: HIV-associated facial lipoatrophy (FLA) is a stigmatizing hallmark for persons living with HIV [PLWH], and can lead to poor social functioning, social isolation, and reduced labour force participation. Treatments for this condition are prohibitively expensive and are not publicly insured in the Province of Ontario, Canada. Information gleaned from an economic evaluation of treatments for FLA could inform policy decision making concerning coverage. Method: Decision-analytic techniques were used to estimate the lifetime incremental costs and quality-adjusted life years (QALYs) gained from use of either Poly-l-lactic acid or Polyalkylimide gel from the perspectives of society and the Ontario Ministry of Health. Disease progression probabilities and utilities were derived from the literature. Costs were obtained through interviews with product distributors and physicians who perform these treatments. Costs were valued in 2009 Canadian Dollars. Costs and outcomes were discounted annually at 3%. Findings: Treatments using Polyalkylimide gel exhibit such a cost advantage over those using Poly-l-lactic acid that they more than compensate for the health-related quality of life advantages of Poly-l-lactic acid. From a Ministry of Health perspective, the incremental cost-utility ratios for Polyalkylimide gel or Poly-l-lactic acid compared to no treatment were $45,457 CAD or $57,352 CAD per QALY, respectively, $1.00 CAD = $0.876 USD). From a societal perspective the equivalent ratios were $48,583 CAD and $66,608 CAD respectively. These findings were not altered in the sensitivity analyses. Conclusion: FLA treatments for PLWH enhance QALYs and meet conventional cost-utility thresholds. The incremental cost per QALY for Polyalkylimide gel was lower than that for Poly-l-lactic acid.

Antiretroviral drugs are ineffective at treating viral infection in the brain because they cannot freely diffuse across the blood-brain barrier (BBB). Therefore, HIV-1 viral replication persists in the central nervous system (CNS) and continues to augment the neuropathogenesis process. Nanotechnology can play a pivotal role in HIV-1 therapeutics as it can increase drug solubility, enhance systemic bioavailability, and at the same time offer multifunctionality. Moreover, following conjugation with transferrin (Tf), these drug-loaded nanoformulations can permeate across biological barriers such as the blood brain barrier (BBB) via a receptor mediated transport mechanism. In the current study, we have stably incorporated the antiviral drug, Saquinavir, within Tf-conjugated quantum rods (QRs), which are novel nanoparticles with unique optical properties. We have evaluated the transversing ability of the QR-Tf-Saquinavir nanoformulation across an in vitro model of BBB. In addition, we have analyzed the subsequent antiviral efficacy of this targeted nanoformulation in HIV-1 infected peripheral blood mononuclear cells (PBMCs), which are cultured on the basolateral end of the in vitro BBB model. Our results show a significant uptake of QR-Tf-Saquinavir by brain microvascular endothelial cells (BMVECs), which constitute the BBB. In addition, we observed a significant enhancement in the transversing capability of QR-Tf-Saquinavir across the BBB, along with a marked decrease in HIV-1 viral replication in the PBMCs. These observations indicate that drug-loaded nanoparticles can deliver therapeutics across the BBB. These results highlight the potential of this nanoformulation in the treatment of Neuro-AIDS and other neurological disorders.

Objectives: To value the role of leptin, adiponectin and cystatin C in HIV infected patients treated with combined antiretroviral therapy (cART) subdivided for cardiovascular risk (CVR). Methods: 56 HIV+ cART treated patients were screened by Framingham score and subdivided in 2 groups: A) 15 with “high” CVR (>10%) and B) 41 with “low” CVR (<10%). Viro-immunological parameters, triglycerides, total cholesterol, HDL and LDL cholesterol, blood pressure, microalbuminuria, fasting glucose, insulinemia, HOMA-IR, CRP, cystatin C, IL-18, IL-6, leptin, adiponectin, antropometric parameters and total abdominal tissue (TAT), subcutaneous (SAT) and visceral abdominal tissue (VAT) were measured. Results: Group A showed statistically higher levels of parameters of glucose and lipid metabolism, cystatin C, microalbuminuria, blood pressure and BMI. Moreover levels of IL-6, IL-18 and leptin were statistically higher in group A, whereas adiponectin was statistically increased in group B. Data showed a positive correlation between VAT, leptin levels (r=0.37, p=0.005) and IL-18 (r=0.32, p=0.01), and a negative correlation between VAT and adiponectin (r=-0.30, p=0.02). Finally group A showed statistically higher levels of cystatin C and there was a positive correlation between CVR and cystatin C (r=0.39, p=0.003). Conclusions: The main results of this study are that HIV positive subjects cART treated with “high” CVR have increased plasma levels of leptin, IL-6, IL-18 and cystatin C and hypoadiponectinemia. Moreover, the positive correlation between CVR and cystatin C found in this study for the first time in HIV positive patients, indicates that cystatin C could serve as early marker of enhanced CVR in the HIV-infected population.

Objective: To evaluate common carotid artery intima-media thickness (CCIMT) and cardiovascular risk factors in HIV-infected adolescents on combination antiretroviral therapy (cART). Methods: 23 HIV-infected adolescents were matched with 19 healthy subjects by gender, age and body mass index (BMI). CCIMT was measured by Echo-Doppler ultrasound. Bootstrapped multiple linear regression was used to identify potential predictors of CCIMT including HIV status, gender, age, BMI, waist circumference, HDL-cholesterol, LDL- cholesterol, triglycerides, folate, homocysteine and insulin resistance as detected by the homeostasis model assessment, mean blood pressure, and CD36 expression. Results: In the pooled sample, age ranged from 17 to 23 years and BMI between 16.0 and 25.6 kg/m2. Mean (SD) CCIMT was higher in HIV-infected than in healthy subjects [0.5 (0.1) vs 0.4 (0.1) mm, p < 0.001]. Higher values of CCIMT were associated with HIV infection (p < 0.001) and male gender (p < 0.001). CCIMT was also associated with the duration of treatment in subjects with the longest cART exposure, i.e. those exposed to a PI-based and/or NNRTI-based regimen plus a single or double NRTI (p = 0.019). Conclusion: HIV infection and longer duration of cART are associated with higher CCIMT in adolescents and young adults.