title: Indoleamine 2,3-dioxygenase is increased in hemodialysis patients and affects immune response to hepatitis B vaccination.
abstract: BACKGROUND
  Acquired immunity is impaired in hemodialysis (HD) patients. Indoleamine 2,3-dioxygenase (IDO) is inducible by inflammation and through tryptophan depletion and generation of kynurenine pathway products suppresses adaptive immune response. In the present study plasma IDO levels were assessed in HD patients. Its effect on response to HBV vaccination program was evaluated.
  
  
  METHODS
  Sixty-six HD patients and twenty-four healthy volunteers enrolled into the study. All the HD patients were initially vaccinated with four double doses of recombinant HBV vaccine. All doses were repeated in patients who had not responded after complete first vaccination series. Only one boost dose was being administered in patients with initial adequate antibody levels against the HBV surface antigen (anti-HBs>10I U/L) who then presented with reduced anti-HBs levels. IDO, CRP, IL-6 and TNF-α were measured by means of ELISA.
  
  
  RESULTS
  Compared to healthy volunteers, IDO levels were twice higher in HD patients. CRP, IL-6 and TNF-α were also much higher in HD patients. IDO levels were almost twice higher in HD patients with inadequate response to HBV vaccination, than in those with adequate immune response. CRP, IL-6 and TNF-α did not differ between the two patients' groups. IDO was negatively correlated with all markers of inflammation in HD patients.
  
  
  CONCLUSIONS
  IDO is increased in HD patients. It is possible that after its initial upregulation due to chronic inflammation, IDO curtails its own provoking agent, i.e., inflammation. Increased IDO suppresses adaptive immunity in HD patients, as it is assessed by the response to HBV vaccination.
authors.affiliation: Department of Nephrology, Medical School, University of Thessaly, Larissa, Greece. teleftheriadis@yahoo.com
authors.forename: Theodoros
authors.initials: T
authors.lastname: Eleftheriadis
authors.forename: Vassilios
authors.initials: V
authors.lastname: Liakopoulos
authors.forename: Georgia
authors.initials: G
authors.lastname: Antoniadi
authors.forename: Ioannis
authors.initials: I
authors.lastname: Stefanidis
authors.forename: Grammati
authors.initials: G
authors.lastname: Galaktidou
mesh_terms: D056704:Adaptive Immunity; D000368:Aged; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D005260:Female; D006509:Hepatitis B / Q000276:immunology* / Q000517:prevention & control; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines / Q000008:administration & dosage*; D006801:Humans; D007117:Immunization, Secondary; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; C508600:IL6 protein, human; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein