Alcohol abuse also leads to a significant elevation of activated CD8 T cells, measured by increased expression of human leukocyte antigen (HLA)-DR in adult males who consumed an average of 23 drinks/day for approximately 27 years that persisted for up to 10 days of abstinence (Cook, Garvey et al. 1991). Similarly, an increased percentage of CD8 T cells expressing HLA-DR and CD57 was reported in the group of male alcoholics with self reported average alcohol consumption of approximately 400g/day for approximately 26 years (Cook, Ballas et al. 1995). Mice that consumed 20% (w/v) ethanol in water for up to 6 months, also showed an increased percentage of activated T cells as measured by increased expression of CD43, Ly6C, rapid IFN-γ response, and increased sensitivity to low levels of TCR stimulation (Song, Coleman et al. 2002, Zhang and Meadows 2005). Taken together, these studies suggest that chronic alcohol-induced T cell lymphopenia increases T cell activation and homeostatic proliferation resulting in increased proportion of memory T cells relative to naïve T cells. In contrast, moderate alcohol increased frequency of lymphocytes (Figure 1).
