- Both alcohol abuse and HIV infection are believed to compromise immune function.
- A new study evaluates the relationship between alcohol consumption and HIV disease progression among patients receiving highly active antiretroviral therapy (HAART).
- HIV-infected patients with a history of alcohol problems, who are receiving HAART, and are currently drinking, have greater HIV progression than those who do not drink.
In the United States, alcohol problems appear to be more prevalent among people with the human immunodeficiency virus (HIV) than among the general population. Both alcohol abuse and HIV infection are believed to compromise immune function. In fact, alcohol use may accelerate HIV disease progression. Recent research, published in the May issue of Alcoholism: Clinical & Experimental Research, has found that HIV-infected patients with a history of alcohol problems, who are receiving highly active antiretroviral therapy (HAART), and are currently drinking, have greater HIV progression than those who do not drink.
"Part of our interest in examining the relationship between alcohol use and HIV infection was based on clinical experience," explained Jeffrey H. Samet, professor of medicine and public health at Boston University, and the study's first author. "In the urban setting where I work, a substantial number of patients - with or without HIV, but even more so with HIV - have had alcohol problems. In the world before HIV, we knew that chronic alcohol use led to problems that are more common in immunodeficiency states such as tuberculosis and pneumonia. Of course we also know that HIV attacks the immune system. So you can pose the question, 'could these two things - HIV and alcohol - be interacting in some way that makes the immune state worse than just HIV alone?'"
"Although we do not yet understand how alcohol directly interacts with the already compromised immune system of a human infected with HIV," added Amy C. Justice, a researcher with the University of Pittsburgh School of Medicine and the VA Pittsburgh Healthcare System, "nonhuman studies suggest that heavy alcohol consumption can immediately elevate viral load, presumably by decreasing the ability to kill virus."
Justice added that the indirect effects of alcohol are also cause for concern. "Heavy alcohol consumption is known to limit a person's ability to adhere to HIV treatment," she said, "and nonadherence is known to lead to more rapid disease progression. Further, alcohol is known to exacerbate common comorbid conditions among those with HIV infection, such as hepatitis C or chronic hepatitis B. Finally, heavy alcohol consumption may also lead to increased rates of serious toxicity from antiretroviral therapy as both can be toxic to the liver and bone marrow. Thus, heavy alcohol consumption may lead to nonadherence and even complete cessation of antiretroviral therapy through a multitude of mechanisms."
The current treatment for HIV infection, HAART, has contributed to a steady decrease in HIV morbidity and mortality. The term does not refer specifically to any particular medication, but to a minimum of three antiretroviral medications that are known to work against HIV, which belongs to a class of retroviruses.
For this study, researchers examined 349 (276 or 79% males; 73 or 21% females) HIV-infected individuals with a history of alcohol problems. HAART use during the previous month was determined; as was alcohol consumption, and then quantified as none, moderate, or at-risk. In addition, two markers of HIV disease progression were assessed: CD4 cell counts, and HIV ribonucleic acid (RNA) levels.
"CD4 cells are immune cells in your body that work to keep you from getting infections," explained Samet. "There's a certain normal level in the body, in the range of 800 to 1,000. Over time, with HIV, this level will fall on average about 60 to 80 cells a year. Over the course of eight to 10 years, you move from a 'normal' state down to one where complications associated with an infected immune system occur. HIV RNA levels refer to how much virus is circulating in your body. For example, if you have more than 100,000 virus, you will have a much more rapid fall of your CD4 count than someone who has a few hundred or 1,000 virus. These two markers provide complementary information about disease progression. It's been said they're like a train heading toward a cliff; HIV RNA is the speed at which the train is traveling, and CD4 is the distance of the engine from the edge of the cliff."
The study found that among HIV-infected patients with a history of alcohol problems and who were treated with HAART, those who consumed moderate or at-risk amounts of alcohol had higher HIV RNA levels and lower CD4 cell counts, compared with those who did not drink. No significant differences were found in HIV RNA levels or CD4 cell counts among HIV-infected patients who consumed alcohol but were not on antiretroviral therapy.
Both Samet and Justice said that heavy alcohol consumption is clearly ill advised for HIV-infected individuals on antiretroviral therapy. "The data isn't strong enough to make recommendations, particularly about moderate alcohol use," said Samet, "but obviously we have concerns. These individuals need to be cautious. Furthermore, I think it's a reasonable hypothesis that lots of alcohol use by HIV-infected individuals, even by those who haven't had past alcohol problems, may raise these same issues. But that's a future line of research."
Justice added that "future studies need to determine the degree to which this association is explained by patient behavior, such as nonadherence, and the degree to which it appears to be a direct effect of alcohol on the immune system of individuals infected with HIV."
Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors of the ACER paper included: Nicholas J. Horton of the Departments of Medicine and Biostatistics; Elizabeth T. Traphagen of the Department of Medicine; Sarah M. Lyon of the Boston University Schools of Medicine; and Kenneth A. Freedberg of the Department of Biostatistics and the General Medicine Division and Partners AIDS Research Center, Massachusetts General Hospital in Boston. The study was funded by the National Institute on Alcohol Abuse and Alcoholism.