HIV-positive patients who are heavy alcohol drinkers respond less well to HAART, according to a study conducted amongst HIV-infected drug users in Miami, published in the March 2003 edition of the journal Addiction Biology. A similar study in HIV-positive men and women with a history of alcohol problems, published in the May edition of Alcoholism: Clinical and Experimental Biology, also found that `at-risk` alcohol users on HAART had higher viral load and lower CD4 cell counts.
There are conflicting data about the role of alcohol in HIV disease progression. Although some investigations have found no link between disease progression and response to HAART between drinkers and non-drinkers, a recent study suggested that heavy alcohol consumption could stimulate latent HIV into replication. In addition, it is thought that heavy drinking can contribute to poor nutrition and this can suppress the immune system. Heavy drinking could negatively affect adherence to HAART as well as damaging the liver’s ability to process antiretrovirals.
To help clarify the role of alcohol in HIV disease progression and the effect of HAART, investigators in Miami looked at the impact of different levels of alcohol consumption on the CD4 cell count, HIV viral load and nutritional status of 220 HIV-positive drug users.
The average age of patients was 40 years. The majority (70%) were African Americans, and the dominant drug used by patients was crack cocaine (63%), with 46% using cocaine, and 60% cannabis.
A little under two thirds (63%) of patients were categorised as heavy drinkers (defined as drinking alcohol three to four times a week), 21% drank once a week or less and were classed as light drinkers and 16% reported no alcohol use. Men were three times more likely to be heavy drinkers than women.
When investigators looked at the impact of alcohol on nutrition, they found that heavy drinkers were more likely to be malnourished, with 66% having low serum albumin levels, compared to 22% of light drinkers and 16% of non-drinkers. Serum albumin has been found to be an independent predictor of HIV disease progression (see links below).
The average CD4 cell count of heavy drinkers was slightly lower than light users and non-drinkers (381 cells/mm3 versus 399 cells/mm3 and 425 cells/mm3. However, when the investigators looked at the immunological status of the 63% of patients taking HAART, they found that heavy alcohol users on were twice as likely to have a CD4 cell count below 500 cells/mm3 compared to light or non -drinkers.
Average viral load amongst the study samples was just over 58,000 copies/mL, with 24% of patients being undetectable. Moreover, only 14% of heavy drinkers had an undetectable viral load compared to 24% of light users, and univariate analysis revealed that HAART-treated patients who drank heavily were four times less likely to achieve an undetectable viral load (95% CI 1, 2-17, p=0.04), compared to light and non-drinkers.
The investigators note that heavy drinkers had poorer immunological function and viral response to therapy. They suggest that several factors could be responsible, including poor drug absorption, interactions, and adherence. They note that alcohol is metabolised by the same cytochrome p450 pathway responsible for the metabolising of protease inhibitors and NNRTIs. They conclude that heavy alcohol use could “block the effectiveness” of HAART and stress the importance of evaluating patterns of drug use.
The second study, carried out by Boston University and Pittsburgh School of Medicine, found that amongst 349 HIV-positive individuals with a history of alcohol abuse, `at risk` drinkers on HAART had higher viral load and lower CD4 counts than those who consumed moderate amounts of alcohol, or none at all. The same relationship was not apparent amongst HIV-positive people not receiving HAART.
Dr Amy Justice of Pittsburgh University said: "Future studies need to determine the degree to which this association is explained by patient behaviour, such as non-adherence, and the degree to which it appears to be a direct effect of alcohol on the immune system of individuals infected with HIV."
Further information on this website
Alcohol increases SIV 64-fold in monkeys: implications for HIV transmission - news story
Low albumin levels predict death in HIV-positive women, even if taking HAART - news story
Miguez MJ et al. HIV treatment in drug abusers: impact of alcohol use> Addiction Biology 8: 33-37, 2003.