Both HIV-1 infection and chronic alcohol abuse adversely affect lung health. For example, through multiple mechanisms, chronic alcohol abuse increases one's susceptibility to pneumonia, particularly pneumonia caused by certain serious pathogens. Similarly, pneumonia caused by opportunistic pathogens is very common in HIV-infected patients, at least in part because HIV-1 attacks the immune cells of the lungs and interferes with their functions. Alcohol abuse also increases the risk of developing acute respiratory distress syndrome, a serious acute lung condition; however, the association of this syndrome with HIV-1 infection remains unclear. Chronic lung conditions potentially caused or exacerbated by chronic alcohol abuse include asthma, emphysema, or chronic bronchitis, although the findings to date are equivocal. However, growing evidence indicates that HIV-1 infection increases the risk of chronic pulmonary diseases such as emphysema, lung cancer, and excessive blood pressure in the vessels supplying the lung (i.e., pulmonary hypertension). Both alcohol abuse and HIV infection can impair lung function through various mechanisms, including increasing oxidative stress and enhancing antioxidant deficits, preventing full activation of the lung's immune cells, and contributing to zinc deficiency. However, the interactions between alcohol abuse and HIV-1 infection in contributing to the range of lung disorders have not been studied in detail. KEY WORDS: Alcohol abuse; chronic alcohol effect; human immunodeficiency virus1; lung; lung function; pneumonia; pulmonary diseases
Despite considerable experimenthat both human immunodeinfection and chronic alcohosusceptible to serious lung infections surprisingly little information is availactions between these two conditionssame is true for lung diseases such as chronic bronchitis, lung cancer, and p tal and clinical evidence ficiency virus (HIV)1 l abuse render people (i.e., pneumonia), able regarding the interon lung health. The asthma, emphysema,1 ulmonary hypertension, which are not caused by infections but result from other disease processes. Thus, in most cases, little or no specific evidence suggests that the effects of concurrent HIV-1 infection and alcohol abuse are as great as or even greater than the sum of the effects of both individual conditions (i.e., are additive or synergistic) on these common noninfectious lung diseases in humans. However, findings from experimental animal models provide compelling reasons to infer that alcohol abuse has serious consequences on lung health in HIV-1- infected people. Moreover, recent discoveries in experimental models that complement researchers' understanding of the pathophysiology of HIV-1 infection and alcohol abuse in humans have provided clues to potential new therapies for patients with infectious and noninfectious lung disease. This article summarizes some of the experimental and clinical evidence that implicate alcohol abuse as a potential exacerbating factor on lung health in HIV-1-infected people.
ALCOHOL, HIV-1 INFECTION, AND PNEUMONIA
Alcohol is the most frequently abused drug in the world (Lieber 1995). In the United States, 50 percent of the population regularly consumes alcohol, and in 2002 nearly 18 million American adults met the clinical diagnostic criteria for alcohol abuse or alcohol dependence (Grant et al. 2004). According to the most recent definition established by the American Psychiatric Association (2000) in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR), substance use disorders, which have been separated into substance abuse and substance dependence, are characterized by repeated use despite adverse social and/or physical consequences. Dependence has been considered a more advanced stage of a substance use disorder with specific tolerance and withdrawal phenomena. In other words, abuse is characterized by the use of a substance with psychoactive properties either in socially inappropriate ways or in spite of serious medical, legal, or social consequences, such as disruption of one's personal or professional life. …