Acute changes in immune biomarkers under low- and moderate-dose alcohol in light and heavy drinkers: A randomized,...

Alcohol consumption modulates immune function, in part by promoting microbial translocation. This process is thought to trigger an acute-phase immune response, contributing to alcohol-related immune modulation. However, most evidence on these effects arises from preclinical models. Additionally, existing human studies lack a placebo control, rely on a single alcohol dose, or fail to account for individual drinking history.

This study examined in vivo concentrations of lipopolysaccharide (LPS, a marker of microbial translocation), acute-phase proteins, cytokines, and chemokines under low-dose alcohol, moderate-dose alcohol, and placebo using a within-subjects design in light and heavy drinkers. Participants (N = 32) were light drinkers (n = 15) and nontreatment-seeking heavy drinkers (n = 17). Groups did not differ on demographics. Participants received each dose condition in randomized order. Blood samples were collected at baseline and at hourly intervals for 4 h. Plasma concentrations of LPS, acute-phase proteins (LPS binding protein [LBP], soluble cluster of differentiation 14 [sCD14], and soluble cluster of differentiation 163 [sCD163]), and cytokines/chemokines (interleukin 6 [IL-6], interleukin 8 [IL-8], interleukin 10 [IL-10], monocyte chemoattractant protein [MCP-1], and tumor necrosis factor alpha [TNF-α]) were quantified using immunoassays. Linear mixed models tested effects of dose condition, drinker group, time, and the three-way interaction. Further analyses tested associations of LPS, LBP, sCD14, and sCD163 with cytokines/chemokines.

The three-way interaction of dose by group by time was significant for IL-6 (p = 0.042), IL-8 (p = 0.039), MCP-1 (p = 0.001), and TNF-α (p = 0.001). LPS was associated with concentrations of interleukins. Levels of sCD163 were 43% higher in heavy drinkers overall. Heavy drinkers exhibited apparent conditioned peripheral immune suppression, wherein the expectation of alcohol elicited selective immunosuppressive responses.

This study offers novel in vivo evidence that alcohol-induced changes in immune function are dependent on both acute dose and chronic drinking behavior.