Abstract # 1812 Cytokine patterns in Interferon-alpha induced Persistent Fatigue

Abstract

Interferon-alpha(IFN-alpha) used to treat Chronic Hepatitis C Viral(HCV) infection induces acute fatigue, which can persist post-treatment. This study aimed to examine cytokine changes as a putative biological mechanism. We recruited 22 patients receiving IFN-alpha. Plasma levels of IL-6-IL-7-IL-17a and TNF-alpha were assessed at baseline, treatment weeks (TW) 4 and 24, and six-months post-treatment. Fatigue was assessed using the Chalder Fatigue Questionnaire (CFQ) at the same time points. Patients were stratified according to whether fatigue levels at follow-up had improved (Resolved Fatigue; RF, n = 13) or worsened (Persistent Fatigue; PF, n = 9). Wilcoxon tests showed that the PF group experienced a significant increase in levels of IL-17a and IL-6 in the first four weeks of treatment (median: 8.22 vs 8.42 pg/ml, p = .022; 3.17 vs 3.53 pg/ml, p = .007). The RF group did not have the same change in IL-17a (9.18 vs 8.93, p = .463) though did have an increase in IL-6 (2.80 vs 3.13, p = .026). In the RF group, there was a decrease in IL-6 and IL-17a between TW24 and six-months post-treatment (3.07 vs 2.70, p = .053; 8.86 vs 8.57, p = .047), which was not seen in the PF group (3.74 vs 3.21, p = .262; 8.25 vs 8.29, p = .161). Paired t-tests showed that both groups had significant increases in TNF-alpha levels during treatment, then a post-treatment decrease. Our data shows differential patterns of change in the cytokines IL-17a and IL-6 in those patients who experience persistent fatigue, with higher levels in response to the initial treatment doses, and no decrease in the six-months post-treatment.