2 - Ethanol, Immune Reactions and the Digestive System

Abstract

SUMMARY AND CONCLUSIONS The digestive tract is of key importance in normal immunity. It participates in the removal and sequestration of extraneous antigens through the gastrointestinal mucosa and Kupffer cells of the liver, which is also the site of production of antigens and immunoglobulins. Changes in the immune system may produce or accentuate ethanol-induced enterocolitis, liver injury, pancreatic disease or neoplasia of the digestive tract. Cytotoxicity, chemotaxis and fibrogenesis, characteristic of alcohol-induced tissue injury, are related to cell-mediated and humoral immunity. Cell- and antibody-mediated immunological hyperactivity leads to chronic liver and pancreatic disease. A hypersensitivity reaction to congeners of ethanol occasionally leads to acute enterocolitis. Reduction in immunocompetence attendant on ethanol, nutrient depletion and altered cellular hemostasis contributes to the development of chronic tissue injury and neoplasia in the alcoholic. Immunological tests facilitate recognition of ethanol-induced intestinal, pancreatic and liver disease. The use of CEA alpha-fetoprotein, organ non-specific antibodies, and organ-specific target antigens aids in diagnosis. Simple, accurate immunological tests to monitor serially cytotoxicity and fibrogenesis now permit monitoring of the natural history and influence of therapy on ethanol-induced injury. Prevention and treatment of ethanol-induced lesions of the digestive tract require special attention to immunological abnormalities. Correction of deficits of nutrients is essential to restore normal immunocompetence and repair cell injury, requisite for disposal of exogenous antigens and endogenous neoantigens. Pharmacological immunosuppressants may reduce cytotoxicity, fibrogenesis or mitogenesis resulting from altered immunological reactivity.