Circulating cytokines as biomarkers of alcohol abuse and alcoholism

Abstract

There are currently no consistent objective biochemical markers of alcohol abuse and alcoholism. Development of reliable diagnostic biomarkers that permit accurate assessment of alcohol intake and patterns of drinking is of prime importance to treatment and research fields. Diagnostic biomarker development in other diseases has demonstrated the utility of both open, systems biology, screening for biomarkers and more rational focused efforts on specific biomolecules or families of biomolecules. Long-term alcohol consumption leads to altered inflammatory cell and adaptive immune responses with associated pathologies and increased incidence of infections. This has led researchers to focus attention on identifying cytokine biomarkers in models of alcohol abuse. Alcohol is known to alter cytokine levels in plasma and a variety of tissues including lung, liver, and very importantly brain. A number of cytokine biomarker candidates have been identified, including: tumor necrosis factor-alpha, interleukin (IL)-1-alpha, IL-1-beta, IL-6, IL-8, IL-12, and monocyte chemoattractant protein-1. This is an emerging and potentially exciting avenue of research in that circulating cytokines may contribute to diagnostic biomarker panels, and a combination of multiple biomarkers may significantly increase the sensitivity and specificity of the biochemical tests aiding reliable and accurate detection of excessive alcohol intake.

Figure 1

Alterations of circulating cytokines in response to ethanol originate in a variety of tissues/organs. With increasing amount and duration of ethanol administration, initial changes in cytokine levels may feedback on the body causing secondary changes. Either individually or as panels, circulating cytokines may serve as diagnostic markers of alcohol abuse and alcohol-induced tissue damage.