Directions for biomedical research in alcohol and HIV: where are we now and where can we go?

A systematic review of the impact of alcohol use disorders on HIV treatment outcomes, adherence to antiretroviral therapy and health care utilization

BACKGROUND

Alcohol use disorders (AUDs) are highly prevalent and associated with non-adherence to antiretroviral therapy, decreased health care utilization and poor HIV treatment outcomes among HIV-infected individuals.

OBJECTIVES

To systematically review studies assessing the impact of AUDs on: (1) medication adherence, (2) health care utilization and (3) biological treatment outcomes among people living with HIV/AIDS (PLWHA).

DATA SOURCES

Six electronic databases and Google Scholar were queried for articles published in English, French and Spanish from 1988 to 2010. Selected references from primary articles were also examined.

REVIEW METHODS

Selection criteria included: (1) AUD and adherence (N=20); (2) AUD and health services utilization (N=11); or (3) AUD with CD4 count or HIV-1 RNA treatment outcomes (N=10). Reviews, animal studies, non-peer reviewed documents and ongoing studies with unpublished data were excluded. Studies that did not differentiate HIV+ from HIV- status and those that did not distinguish between drug and alcohol use were also excluded. Data were extracted, appraised and summarized.

DATA SYNTHESIS AND CONCLUSIONS

Our findings consistently support an association between AUDs and decreased adherence to antiretroviral therapy and poor HIV treatment outcomes among HIV-infected individuals. Their effect on health care utilization, however, was variable.

Alcohol impairs interferon signaling and enhances full cycle hepatitis C virus JFH-1 infection of human hepatocytes

Alcohol drinking and hepatitis C virus (HCV) infection frequently coexist in patients with chronic liver disease. There is limited information, however, about the impact of alcohol on host cell innate immunity and full cycle replication of HCV. This study investigated whether alcohol impairs the intracellular innate immunity in human hepatocytes, promoting HCV infection and replication. Alcohol treatment of human hepatocytes before, during and after viral infection significantly enhanced full cycle HCV replication. Alcohol suppressed intracellular expression of type I interferons (IFN-α/β) in human hepatocytes. Investigation of the mechanisms responsible for the alcohol action revealed that alcohol inhibited the expression of the IFN regulatory factors (IRF-5 and IRF-7), and signal transducer and activator of transcription (STAT-1 and STAT-2), the key positive regulators in type I IFN signaling pathway. In addition, alcohol induced the expression of suppressors of cytokine signaling (SOCS-2 and SOCS-3), the key negative regulators of IFN-α/β expression. These in vitro findings suggest that alcohol, through modulating the expression of key regulators in IFN signaling pathway, inhibits type I IFN-based intracellular innate immunity in hepatocytes, which may contribute to the chronicity of HCV infection and the poor efficacy of IFN-α-based therapy.

The role of alcohol on platelets, thymus and cognitive performance among HIV-infected subjects: are they related?

Our objective was to evaluate whether thrombocytopenia and small thymus volume, which may be associated with hazardous alcohol consumption, are predictors of cognitive performance after highly-active antiretroviral treatment (HAART). To achieve this goal 165 people living with HIV starting HAART underwent thymus magnetic resonance imaging, cognitive (HIV Dementia Score [HDS] and the California Verbal Learning Test [CVLT]), immune and laboratory assessments at baseline and after 6 months of HAART. At baseline, hazardous alcohol consumption was significantly correlated with both thymus size (r = -0.44, p = 0.003) and thrombocytopenia (r = 0.28, p = 0.001). Of interest, thrombocytopenic patients were characterized by a smaller thymus size. Individuals with and without cognitive impairment differed in alcohol consumption, platelet counts and thymus size, suggesting that they may be risk factors for neurological abnormalities. In fact, after HAART hazardous alcohol use associations with thrombocytopenia were related to cognitive decline (learning = -0.2 +/- 0.8, recall = -0.3 +/- 0.1 and HDS = -0.5). This contrasted with improvements on every cognitive measure (learning = 1.6 +/- 0.3, p = 0.0001, recall = 2.2 +/- 0.4, p = 0.0001 and HDS = 1.0, p = 0.05) in those with neither alcohol use nor thrombocytopenia. In adjusted analyses for sociodemographics, adherence and immune measurements, reduced thymus size was associated with a 90% and thrombocytopenia with a 70% increase in the risk of scoring in the demented range after HAART (RR = 1.9, p < 0.05 and RR = 1.7, p = 0.03) and with low CVLT scores (thymus volume RR = 2.0, p = 0.04, chronic alcohol use p = 0.05 and thrombocytopenia p = 0.06). Thymus volume and platelet counts were negatively affected by alcohol and were predictors of cognitive performance and improvements after HAART. These results could have important clinical and therapeutic implications.

Trends in perimortal conditions and mortality rates among HIV-infected patients

OBJECTIVES

To describe trends in perimortal conditions (pathological conditions causing death or present at death but not necessarily the reported cause of death) during three periods related to the availability of HAART, pre-HAART (1992-1995), early HAART (1996-1999), and contemporary HAART (2000-2003); annual mortality rates; and antiretroviral therapy (ART) prevalence during 1992-2003.

DESIGN

Multicenter observational clinical cohort in the United States (Adult/Adolescent Spectrum of HIV Disease [ASD] project).

METHODS

Proportionate mortality for selected perimortal conditions, annual mortality rates, and ART prevalence were standardized by sex, race/ethnicity, age at death, HIV transmission category, and lowest CD4 cell count of ASD decedents. Multivariable generalized linear regression was used to estimate trends in proportionate mortality, as linear trends through all three HAART periods, mortality rates, and ART prevalence.

RESULTS

Of 9225 deaths, 58.6% occurred during 1992-1995, 29.5% during 1996-1999, and 11.9% during 2000-2003. Linear trends in proportionate mortality for noninfectious diseases (e.g., liver disease, hypertension, and alcohol abuse) increased significantly; proportionate mortality for AIDS-defining infectious diseases (e.g., pneumocystosis, nontuberculous mycobacterial disease, and cytomegalovirus disease) decreased significantly. Mortality rates decreased from 487.5/1000 person-years in 1995 to 100.6 in 2002. Of 36 256 patients from ASD, 75.7% (standardized average) were prescribed ART annually.

CONCLUSIONS

Among HIV-infected patients, the majority of whom were prescribed ART, the increasing trend in common noninfectious perimortal conditions support screening and treatment for these conditions in order to sustain the trend in declining mortality rates.

Expanding research on the role of alcohol consumption and related risks in the prevention and treatment of HIV/AIDS

This article is a review of some of the major epidemiological, behavioral, biological, and integrative prevention research issues and priorities in the area of HIV/AIDS and alcohol consumption. Drinking alcohol increases both the risk for infection with HIV and related illnesses and the morbidity and mortality of patients who progress to AIDS. New and improved measurement procedures have helped in assessment of the complex patterns of alcohol use, identification of intervening explanatory mechanisms for risk behaviors and contexts, and determination of intervention outcomes. Both the direct and indirect effects of alcohol misuse appear to be major contributors to both the risk for infection with HIV and the transmission of HIV/AIDS at the individual and population levels. There is increasing evidence that perhaps no level of alcohol consumption is "safe" for those who are HIV infected and receiving antiretroviral treatment. Interdisciplinary basic behavioral and biomedical research is needed to develop comprehensive culturally appropriate strategies for programs that can be effectively delivered in community contexts in the United States and abroad and that focus on the integration of our understanding of individual behaviors, high-risk group membership, biological mechanisms, and the social and physical environments that place individuals at risk for HIV infection. High-priority topics include improving adherence to antiretroviral medications, prevention of infection in young minority women in the United States, and treatment of HIV+ pregnant women who are alcohol abusers to prevent adverse fetal outcomes, which is an international focus in under-resourced settings in Africa.

Increased viral replication in simian immunodeficiency virus/simian-HIV-infected macaques with self-administering model of chronic alcohol consumption

Alcohol abuse constitutes a major cohort among HIV-infected individuals. The precise effect of alcohol addiction on HIV pathogenesis remains inconclusive, however. This study was designed to determine the effect of alcohol dependence on virus replication and CD4 profiles in simian immunodeficiency virus/simian-HIV-infected rhesus macaques. A group of 3 male Indian rhesus macaques was adapted to a self-drinking model of alcohol consumption, whereas another group of 3 macaques was provided a Nutrasweet solution. After 7 weeks of alcohol consumption, the alcohol-dependent animals along with controls were intravenously inoculated with a mixture of SHIV(KU), SHIV(89.6)P, and SIV/17E-Fr. These animals were followed for a period of 24 weeks for complete blood cell counts, CD4 cell profiles, and viral loads in the blood and cerebral compartments. The alcohol and control groups showed comparable peak viral loads in the blood. The plasma viral load in the alcohol group was 31- to 85-fold higher than that in the control group at weeks 18 through 24 after infection, however. The pattern of cerebrospinal fluid viral replication was also comparable during the acute phase; however, the virus continued to replicate in the brain of alcohol-dependent animals, whereas it became undetectable in the controls. The extent of CD4 cell loss in the alcohol group was significantly higher than that in the control animals at week 1 after infection.

Alcohol suppresses IL-2-induced CC chemokine production by natural killer cells

BACKGROUND

Natural killer (NK) cells are a critical component of the host innate immune system. We investigated whether alcohol impairs NK cell function, particularly production of CC chemokines induced by interleukin (IL)-2, the natural ligands for CCR5 receptor.

METHODS

Primary NK cells and NK cell line (YTS) were cultured with or without alcohol (10 to 80 mM) for three hours. The culture supernatants were then harvested and used to treat human peripheral blood monocyte-derived macrophages and a HeLa cell line, which expresses CD4, CCR5, and CXCR4 receptors (MAGI cells). CC chemokine expression by YTS and primary NK cells treated with or without alcohol was analyzed with the real-time RT-PCR and ELISA. [Ca(2)(+)]i and Western blot assays were used to determine calcium-mediated intracellular signaling pathway and NF-kappaB p65 expression. HIV strains (Bal and UG024) were used to infect macrophages and MAGI cells. In addition, ADA (macrophage-tropic strain) and murine leukemia virus (MLV) envelope-pseudotyped HIV infection was carried out in macrophages. HIV infectivity was determined by HIV reverse transcriptase (RT) and beta-galactosidase activity assays.

RESULTS

Alcohol inhibited IL-2-induced CC chemokine (CCL3 and CCL4) expression by NK cells. Functional tests demonstrated that this reduced expression of CC chemokines was associated with diminished anti-HIV ability of NK cells. Alcohol also reduced the ability of NK cells to response to CCL3-mediated chemotaxis. Alcohol inhibited IL-2-induced NF-kappaB p65 protein expression and calcium mobilization by NK cells.

CONCLUSIONS

Alcohol, through the inhibition of IL-2-induced NF-kappaB p65 protein expression and intracellular calcium mobilization, suppressed NK cell production of CC chemokines. This suppression of CC chemokine production was associated with diminished anti-HIV activity of NK cells. Thus, by inhibiting NK cell-mediated innate immunity against HIV, alcohol consumption may have a cofactor role in the immunopathogenesis of HIV disease.

HIV treatment in drug abusers: impact of alcohol use

Studies of alcohol use in HIV-1 infected patients have resulted in conflicting and limited information regarding prevalence, as well as impact on HIV replication, disease progression and response to antiretroviral therapy. Alcohol, drug abuse and past medical information, including antiretroviral treatment, were obtained using research questionnaires and medical chart review in 220 HIV-1 infected drug users. A physical examination was conducted and blood was drawn to evaluate immune measures and nutritional status. Heavy alcohol consumption, defined as daily or 3 - 4 times per/week, was reported in 63% of the cohort. Men (odds ratio (OR) = 2.6, 95% CI 1.13 - 5.99, p = 0.013), and participants between 35 and 45 years of age were three times more likely to be heavy alcohol users (p = 0.006 and 0.0009, respectively). Low serum albumin levels were more evident in heavy alcohol users than non-drinkers (p = 0.003). Heavy alcohol users receiving antiretroviral therapy were twice as likely to have CD4 counts below 500 than light or non-drinkers (95% CI, 1 - 5.5, p = 0.03), and highly active antiretroviral therapy (HAART)-treated heavy alcohol users were four times less likely to achieve a positive virological response (95% CI, 1.2 - 17, p = 0.04). Alcohol consumption is prevalent in our HIV-1 infected drug user cohort and significantly impacts both immunological and virological response to HAART treatment.