Clinical Textbook of Addictive Disorders 3rd ed - R. Frances, S. Miller, A. Mack (Guilford, 2005) WW

19. HIV/AIDS and Substance Use Disorders 417AlcoholAlcoholics, many of whom use multiple drugs, are at increased risk of exposureto HIV through high-risk behavior. Alcohol use is increasing worldwide, particularlyin countries in transition and throughout the developing world, whereit is contributing to an increasing number of health and social problems(Monteiro, 2001). Homosexual and bisexual men who drank high volumes ofalcohol had increased HIV seroconversion rates (Penkower et al., 1991).Nearly 20 years of studies have linked alcohol with high-risk behavior ofall types, including sexual behavior (Stall et al., 1986; Baldwin, Maxwell,Fenaughty, Trotter, & Stevens, 2000). In a study of alcohol treatment centers,non-IDUs had higher than expected seroprevalence for HIV that was associatedwith a high prevalence of risky sexual behaviors (Avins et al., 1994). In alarge study of sexually transmitted disease clinic attendees, alcohol was frequentlyused and was associated with other risk factors for HIV infection(Zenilman et al., 1994). Studies of alcohol abusers have described a range ofimmune alterations (Arria, Tarter, & Van Theil, 1991; Cook, 1998). Sincealcoholism and medical morbidity often coexist, it is difficult to distinguishimmune alterations associated with alcoholism per se from those associatedwith alcohol-related morbidity, such as liver disease or other comorbid medicalconditions. Acute exposure to alcohol has demonstrable immune effects, andchronic alcohol abusers, who may have adapted to ethanol effects, showimmune alterations of modest scope, unless they have developed secondaryliver disease or other comorbid medical conditions (Cook, 1998; Schleifer,Keller, Shiflett, Benton, & Eckholdt, 1999). The immune effects that havebeen observed in alcoholics, many of which may relate to the secondary complications,include suppressed natural killer cell activity (NKCA) (Irwin et al.,1990; Ochshorn-Andelson et al., 1994; Ristow, Starkey, & Hass, 1982), shiftsin CD4+ and CD8+ lymphocyte subsets, suggesting abnormal activation(Cook, 1998), and altered monocytic and phagocytic activity (Cook, 1998;Schleifer et al., 1999). Studies from our laboratory found that, compared withchronic alcoholics with no evidence of medical compromise, those with onlyminor such changes showed decreased CD45RA+ (inducer–suppressor/naive)cells, decreased HLA-DR+ (activated) T-cells, and an increased proportion ofcirculating CD56+ natural killer (NK) cells (Schleifer, Benton, Keller, &Dhaibar, 2002). Improvement of CD4+ cell count has been demonstrated aftercessation of alcohol use in some HIV-positive alcoholics (Pol, Artru, Thepot,Berthelot, & Nalpas, 1996).Important in assessing the role of substances of abuse, and especially alcohol,in immune change, is the role of comorbid depressive disorders. Irwin andcolleagues (1990) found decreased NKCA in patients with alcoholism that wasexacerbated significantly in patients with both alcoholism and major depres-