Cognitive efficiency is associated with endogenous cytokine levels in patients with chronic hepatitis C.

The etiology of cognitive dysfunction in chronic hepatitis C (CHC) infection is unknown. Among the possibilities is cytokine activation, which has been associated with cognitive dysfunction in other chronic conditions. The purpose of this study was to investigate the relationship between endogenous IFN-alpha, IL-6, and TNF-alpha and cognitive functioning in CHC patients. Seventy-eight veterans with CHC underwent cognitive testing and measurement of serum cytokines. In patients with detectable IFN-alpha, higher levels of IL-6 and TNF-alpha were related to poorer cognitive functioning. Findings suggest CHC patients with immune responses characterized by elevated IFN-alpha may be at risk for cognitive difficulties.