Oxidative Stress in HIV-1-Infected Injection Drug Users:

Oxidative Stress Predicts All-Cause Mortality in HIV-Infected Patients

Objective

We aimed to assess whether oxidative stress is a predictor of mortality in HIV-infected patients.

Methods

We conducted a nested case-control study in CoRIS, a contemporary, multicentre cohort of HIV-infected patients, antiretroviral-naïve at entry, launched in 2004. Cases were patients who died with available stored plasma samples collected. Two age and sex-matched controls for each case were selected. We measured F2-isoprostanes (F₂-IsoPs) and malondialdehyde (MDA) plasma levels in the first blood sample obtained after cohort engagement.

Results

54 cases and 93 controls were included. Median F₂-IsoPs and MDA levels were significantly higher in cases than in controls. When adjustment was performed for age, HIV-transmission category, CD4 cell count and HIV viral load at cohort entry, and subclinical inflammation measured with highly-sensitive C-reactive protein (hsCRP), the association of F₂-IsoPs with mortality remained significant (adjusted OR per 1 log₁₀ increase, 2.34 [1.23–4.47], P = 0.009). The association of MDA with mortality was attenuated after adjustment: adjusted OR (95% CI) per 1 log₁₀ increase, 2.05 [0.91–4.59], P = 0.080. Median hsCRP was also higher in cases, and it also proved to be an independent predictor of mortality in the adjusted analysis: OR (95% CI) per 1 log₁₀ increase, 1.39 (1.01–1.91), P = 0.043; and OR (95% CI) per 1 log₁₀ increase, 1.46 (1.07–1.99), P = 0.014, respectively, when adjustment included F₂-IsoPs and MDA.

Conclusion

Oxidative stress is a predictor of all-cause mortality in HIV-infected patients. For plasma F₂-IsoPs, this association is independent of HIV-related factors and subclinical inflammation.

High rates of serum selenium deficiency among HIV- and HCV-infected and uninfected drug users in Buenos Aires, Argentina

OBJECTIVE

To describe the prevalence of low serum Se and determine whether HIV, hepatitis C virus (HCV) and/or the types of drugs used are associated with serum Se in a cohort of infected and uninfected drug users.

DESIGN

Independent correlates of low serum Se levels based on data collected from food recalls, physical examinations and clinical questionnaires were identified using multivariate regression analysis.

SETTING

Buenos Aires, Argentina

SUBJECTS

A total of 205 (twenty-five female and 180 male) former and current drug users.

RESULTS

Drug users had an average serum Se level of 69·8 (sd 32·8) μg/d, [corrected] and 82 % were considered deficient (<85 μg/l). [corrected] Multivariate analyses found that HIV- and/or HCV-infected individuals had lower mean Se compared with healthy, uninfected drug users (HIV/HCV co-infection: -25·3 μg/l (se 7·6), P = 0·001; HIV alone: -28·9 μg/l (se 6·9), P < 0·001; HCV alone: -19·4 μg/l (se 7·1), P = 0·006). Current and previous drug use was associated with higher serum Se. Cigarette smoking and heavy alcohol consumption were not found to be associated with Se status.

CONCLUSIONS

Low serum Se levels are highly prevalent among drug users in Buenos Aires, Argentina. Se supplementation and/or dietary interventions may be warranted in drug users who are at high risk for HIV and/or HCV infection.

Reconciling conflicting clinical studies of antioxidant supplementation as HIV therapy: a mathematical approach

BACKGROUND

Small, highly reactive molecules called reactive oxygen species (ROS) play a crucial role in cell signalling and infection control. However, high levels of ROS can cause significant damage to cell structure and function. Studies have shown that infection with the human immunodeficiency virus (HIV) results in increased ROS concentrations, which can in turn lead to faster progression of HIV infection, and cause CD4+ T-cell apoptosis. To counteract these effects, clinical studies have explored the possibility of raising antioxidant levels, with mixed results.

METHODS

In this paper, a mathematical model is used to explore this potential therapy, both analytically and numerically. For the numerical work, we use clinical data from both HIV-negative and HIV-positive injection drug users (IDUs) to estimate model parameters; these groups have lower baseline concentrations of antioxidants than non-IDU controls.

RESULTS

Our model suggests that increases in CD4+ T cell concentrations can result from moderate levels of daily antioxidant supplementation, while excessive supplementation has the potential to cause periods of immunosuppression.

CONCLUSION

We discuss implications for HIV therapy in IDUs and other populations which may have low baseline concentrations of antioxidants.

HIV-1 transgene expression in rats causes oxidant stress and alveolar epithelial barrier dysfunction

Background

HIV-infected individuals are at increased risk for acute and chronic airway disease even though there is no evidence that the virus can infect the lung epithelium. Although HIV-related proteins including gp120 and Tat can directly cause oxidant stress and cellular dysfunction, their effects in the lung are unknown. The goal of this study was to determine the effects of HIV-1 transgene expression in rats on alveolar epithelial barrier function. Alveolar epithelial barrier function was assessed by determining lung liquid clearance in vivo and alveolar epithelial monolayer permeability in vitro. Oxidant stress in the alveolar space was determined by measuring the glutathione redox couple by high performance liquid chromatography, and the expression and membrane localization of key tight junction proteins were assessed. Finally, the direct effects of the HIV-related proteins gp120 and Tat on alveolar epithelial barrier formation and tight junction protein expression were determined.

Results

HIV-1 transgene expression caused oxidant stress within the alveolar space and impaired epithelial barrier function even though there was no evidence of overt inflammation within the airways. The expression and membrane localization of the tight junction proteins zonula occludens-1 and occludin were decreased in alveolar epithelial cells from HIV-1 transgenic rats. Further, treating alveolar epithelial monolayers from wild type rats in vitro with recombinant gp120 or Tat for 24 hours reproduced many of the effects on zonula occludens-1 and occludin expression and membrane localization.

Conclusion

Taken together, these data indicate that HIV-related proteins cause oxidant stress and alter the expression of critical tight junction proteins in the alveolar epithelium, resulting in barrier dysfunction.

Selenium status is associated with accelerated HIV disease progression among HIV-1-infected pregnant women in Tanzania

Selenium deficiency has been implicated in accelerated disease progression and poorer survival among populations infected with HIV in developed countries, yet these associations remain unexamined in developing countries. Among 949 HIV-1-infected Tanzanian women who were pregnant, we prospectively examined the association between plasma selenium levels and survival and CD4 counts over time. Over the 5.7-y median follow-up time, 306 of 949 women died. In a Cox multivariate model, lower plasma selenium levels were significantly associated with an increased risk of mortality (P-value, test for trend = 0.01). Each 0.1 micromol/L increase in plasma selenium levels was related to a 5% (95% CI = 0%-9%) decreased risk of mortality. Plasma selenium levels were not associated with time to progression to CD4 cell count < 200 cells/mm(3) but were weakly and positively related to CD4 cell count in the first years of follow up. Selenium status may be important for clinical outcomes related to HIV disease in sub-Saharan Africa.

NAC/MEA conjugate: a new potent antioxidant which increases the GSH level in various cell lines

I-152 is a prodrug of NAC and MEA with potent pro-GSH effects in human macrophages, astrocytes and lymphocytes. This molecule could be of interest in HIV infection in respect to its antioxidant and anti-HIV activities, but also in other diseases to counteract oxidative stress, that is, inflammation, cardiovascular diseases, and neurodegenerative diseases.