Peripheral inflammatory cytokines and immune balance in Generalised Anxiety Disorder: Case-controlled study

Introduction: Previous investigations have demonstrated that major depression is associated with particular patterns of cytokine signalling. The primary aim of this study was to examine peripheral pro inflammatory and anti-inflammatory cytokines and immune balance in Generalised Anxiety Disorder (GAD). Methods: A case-controlled cross-sectional study design was employed: 54 patients with GAD and 64 healthy controls were recruited. Participants completed self-report measures of anxiety and depression. Two pro-inflammatory and two anti-inflammatory cytokines were measured using multiplex technology. Results: Case-control logistic regression analyses revealed significant differences in serum levels of IL-10, TNF-alpha, and IFN-gamma between GAD and control groups after adjusting for age, gender, body mass index, smoking and alcohol consumption: these group differences were independent of the presence or degree of depression. Comparison of pro-inflammatory to anti-inflammatory cytokine ratios indicated that there were significantly higher ratios of TNF-alpha/lL10, TNF-alpha/lL4, IFN-gamma/lL10, and IFN-gamma/IL4 in the GAD group compared to the control group. Conclusions: This study is the first to investigate both pro- and anti-inflammatory cytokines and their balance in patients with GAD in comparison to healthy controls. The findings indicate a relatively increased pro-inflammatory response and decreased antiinflammatory response and provide the first demonstration of an altered cytokine balance in GAD. Serum cytokine levels in GAD were independent of the presence of depression. (C) 2017 Published by Elsevier Inc. All rights reserved.