Alcohol's contribution to compromised immunity

Abstract

Alcoholics frequently suffer from infectious diseases and have increased rates of some cancers, indicating that alcohol impairs the immune system, which protects the body against this type of damage. Alcohol interferes with the functions of many of the cells and molecules that are part of the immune system. For example, alcohol inhibits the functions of the cells that ingest and destroy invading microorganisms (i.e., neutrophils, monocytes, and macrophages). Both acute and chronic alcohol exposure also alter the production of signaling molecules that help coordinate the immune response (i.e., cytokines). Finally, alcohol adversely affects the functions of the cells that mediate the immune response against specific microorganisms and long-term immunity (i.e., T cells and B cells). As a result, alcoholics have an increased susceptibility to diseases caused by bacterial infections, such as tuberculosis and pneumonia. Alcoholics also may be more susceptible to infections from the virus that causes AIDS. In addition, alcohol intoxication can exacerbate the immune suppression that occurs after traumatic injuries.

Monocyte/macrophage-derived substances potentially affected by alcohol. Monocytes and macrophages produce numerous substances that initiate and regulate inflammatory reactions; attract other immune cells (i.e., chemokines); stimulate T cells; help in the elimination of pathogens, such as bacteria; and perform other functions throughout the body. Alcohol may interfere with the production and secretion of all these substances, thereby impairing the body’s immune response. IL = interleukin; TGF-β = transforming growth factor beta; TNF-α = tumor necrosis factor alpha.