ABSTRACT
Background: Chronic Fatigue Syndrome, also known as Myalgic Encephalomyelitis (CFS/ME), is a debilitating condition that presents with a range of symptoms, including fatigue, cognitive dysfunction, muscular and joint pain, and may be immune-mediated. In particular, patients exhibit abnormal cytokine expression. Similarly, in Multiple Sclerosis (MS), patients display neuroimmunological symptoms, and abnormal cytokine expression, with some overlap in symptomology with CFS/ME. The purpose of this study was to compare Th1, Th2, Th17 cytokines, inflammatory cytokines and chemokines, in healthy controls, CFS/ME and MS patients. Methods: Serum samples were collected from healthy controls (n = 16, mean age = 50 ± 11.85 years), CFS/ME patients (n = 16, mean age = 49.88 ± 9.54 years) and MS patients (n = 11, mean age = 52.75 ± 12.81 years). The concentrations of 27 cytokines (IFN-γ, TNF-α, IL-12, IL-2, IL-1β, IL-4, IL-6, IL-10, IL-13, IL-5, IL-17, IL-1ra, IL-7, IL-8, IL-9, eotaxin, IP-10, MCP-1, MIP1α, MIP1β, PDGF-bb, RANTES, basic FGF, GCSF, GMCSF, VEGF and IL-15) were measured using a Bio-Plex Pro™ kit. Results: IFN-γ, IL-10 and IL-5 were significantly higher in the serum of both CFS/ME and MS patients compared to the healthy controls (p ≤ 0.041). However, only the MS patients had significantly elevated levels of IL-12, IL-1β, IL-4, IL-13, IL-6, IL-17, IL-1ra, IL-7, IL-9, eotaxin, IL-10, MIP1α, basic FGF, GCSF and VEGF compared to the CFS/ME patients and controls (p ≤ 0.04). There were no significant differences between groups for IL-8, MCP-1, MIP1β, RANTES, GMCSF, TNF-α, and IL-2. Conclusion: CFS/ME and MS patients both displayed abnormal cytokine levels, with dual expression of Th1 and Th2 cytokines. Further research into cytokines such as IFN-γ, IL-10 and IL-5, with the use of a specific CFS/ME case definition and sensitive cytokine assays, is required to improve the understanding of the pathophysiology of CFS/ME.