Cytokines in hepatitis C-infected patients with or without opioid maintenance therapy

Abstract Objective: Both chronic hepatitis C virus (HCV) infection and opioids cause altered blood levels of cytokines. Previous studies have investigated levels of selected groups of cytokines in patients on opioid maintenance treatment. Little is known about the levels of multiple cytokines in patients with chronic HCV infection on opioid maintenance treatment. Our aim was to investigate the cytokine profile in patients with active HCV infection with and without opioid maintenance treatment. Methods: We conducted a cross-sectional study in an out-patients population included upon referral for antiviral hepatitis C infection treatment. The level of 27 cytokines was measured in serum using multiplex technology. Patients were interviewed using a modified version of the European addiction severity index. Data pertaining to weight, height, current medication, smoking habits, allergies, previous medical history and ongoing withdrawal symptoms were collected. Non-parametric testing was used to investigate differences in levels of cytokines between the two groups. A 3-model hierarchical regression analysis was used to analyse associations between cytokines and confounding variables. Results: Out of 120 included patients, 53 were on opioid maintenance treatment. Median duration of opioid treatment was 68.4 months. There were no demographical differences between the two groups other than age. IL-1β was lower and eotaxin-1 higher in the group on opioid maintenance treatment than in the non-opioid group. No other inter-group differences in the remaining cytokine levels were found. Conclusion: In HCV infection patients, the impact of chronic opioid administration on peripheral circulating cytokine level is minimal.