Elevated serum levels of TNF-α, IL-6, and IL-18 in chronic methamphetamine users.

Abstract

Chronic methamphetamine use causes aberrant changes in cytokines. Our aim was to analyze the serum levels of tumor necrosis factor α (TNF-α), interleukin (IL)-6, and IL-18 in chronic methamphetamine users. Associations between cytokines levels with the demographic properties, methamphetamine use properties, and psychiatric symptoms in chronic methamphetamine users were also evaluated. Seventy-eight chronic methamphetamine users who did not continue methamphetamine exposure since hospitalization and 64 healthy controls were enrolled. Serum levels of TNF-α, IL-6, and IL-18 were detected using an enzyme-linked immunosorbent assay. Psychopathological symptoms of chronic methamphetamine users were evaluated by the Positive and Negative Syndrome Scale, Beck Depression Inventory (BDI), and Beck Anxiety Inventory. Serum levels of TNF-α, IL-6, and IL-18 were significantly increased in methamphetamine users who did not continue methamphetamine exposure since hospital admission (average days since last methamphetamine use=39.06±7.48) when compared to those in controls. Serum IL-6 levels showed significant positive associations with BDI score and current frequency of methamphetamine use in chronic methamphetamine users. Our results suggest that increased TNF-α, IL-6, and IL-18 levels may have an important role in chronic methamphetamine use-associated psychopathological symptoms.