title: Inflammatory and cell-mediated immune biomarkers in myalgic encephalomyelitis/chronic fatigue syndrome and depression: inflammatory markers are higher in myalgic encephalomyelitis/chronic fatigue syndrome than in depression.
abstract: BACKGROUND
  Depression is an inflammatory disorder while many authors declare myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) to be a functional disorder. The aim of the present study is to compare inflammatory and cell-mediated immune (CMI) responses between depression and ME/CFS.
  
  
  METHODS
  We measured two proinflammatory cytokines (PICs) in plasma, interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α), with enzyme-linked immunosorbent assays, and serum neopterin with a radioimmunoassay in controls, ME/CFS and depressive patients.
  
  
  RESULTS
  Plasma PICs were significantly higher in ME/CFS than in depression and higher in both patient groups than in controls. Increased PIC levels in depression were attributable to the presence of fatigue and physio-somatic symptoms. Serum neopterin did not differ significantly between depression and ME/CFS but was higher in both patient groups than in controls. The significant positive correlations between neopterin and either IL-1 or TNF-α were significantly greater in depression than in ME/CFS.
  
  
  CONCLUSIONS
  Since PICs cause depression-like behaviors and fatigue/malaise, we suggest that inflammation may play a role in the pathophysiology of ME/CFS and depression. Increased neopterin also seems to contribute to the pathophysiology of both disorders. This study has detected a shared 'pathway phenotype', i.e. disorders in inflammatory and CMI pathways, which underpins both ME/CFS and depression and, therefore, may explain the co-occurrence of both disorders. ME/CFS and depression are discriminated from each other by increased PICs in ME/CFS and differences in the immune cell communication networks.
authors: Maes Clinics, TRIA, Bangkok, Thailand. dr.michaelmaes @ hotmail.com
authors: Michael
authors: M
authors: Maes
authors: Frank N M
authors: FN
authors: Twisk
authors: Karl
authors: K
authors: Ringel
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D016207:Cytokines / Q000097:blood*; D003865:Major Depressive Disorder / Q000453:epidemiology / Q000276:immunology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D015673:Fatigue Syndrome, Chronic / Q000453:epidemiology / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D007249:Inflammation / Q000097:blood / Q000276:immunology*; D008297:Male; D019798:Neopterin / Q000097:blood*; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D016207:Cytokines; D019798:Neopterin