Aims
Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) is a disabling illness with an unknown aetiology and diagnosis is based on symptom-specific criteria. Immunological dysregulation and cytokine abnormalities are consistent in CFS/ME. As recent studies have highlighted the importance of assessing severity subgroups in the illness, the purpose of this study was to further examine the relationship between severity subgroups in CFS/ME, assessing Th1/Th2/Th17 and inflammatory cytokines in severe (housebound) and moderate (mobile) CFS/ME patients.
Methods
The Centres for Disease Prevention and Control (1994 CDC) Criteria for CFS/ME was used to define CFS/ME participants and severity scales such as the Fatigue Severity Scale (FSS), Dr. Bell’s Disability Scale, the FibroFatigue Scale and the Karnofsky Performance Scale (KPS) were used to confirm CFS/ME subgroups as moderate/mobile or severe/housebound. Participants included healthy controls (n = 22, age = 40.14 + 2.38), moderate/mobile (n = 22; age = 42.09 + 2.72) and severe/housebound (n = 19; age = 40.21 + 1.57) CFS/ME patients. Serum samples were assessed using Bio-Plex Assays for cytokines analyses. Cytokines measured included IL-1ββ, IL-1ra, IL-2, IL-7, IL-10, IL-17, TNF-αα and IFNγγ.
Results
The results found IL-1ββ was significantly reduced in severe CFS/ME compared to moderate patients (p = 0.002). IL-7 was significantly increased in the severe group compared to controls and moderate CFS/ME (p = 0.000, 0.000 respectively). IFN-γγ was also increased in severe CFS/ME compared to moderate CFS/ME (p = 0.025).
Conclusion
This is the first study to show variations in cytokines in moderate and severe CFS/ME patients with all significant differences being between CFS/ME severity groups. This study supports the notion that it seems necessary for CFS/ME patient severity subgroups to be classified and identified in both research and clinical settings.
