Plasma indoleamine 2,3-dioxygenase concentration is increased in hemodialysis patients and may contribute to the pathogenesis of coronary heart disease.
BACKGROUND
Coronary heart disease (CHD) is the leading cause of death in hemodialysis (HD) patients. Inflammation contributes to the pathogenesis of atherosclerosis in this population. Indoleamine 2,3-dioxygenase (IDO), an enzyme with immunomodulatory properties, was evaluated in HD patients with or without CHD.


METHODS
Of the total of 66 HD patients, 22 of them with CHD were confirmed by coronary angiography and 24 healthy volunteers were enrolled in the study. Plasma IDO was assessed by means of enzyme-linked immunosorbent assay. Serum interleukin-6 (IL-6) and C-reactive protein (CRP) were also measured.


RESULTS
Compared with healthy volunteers, plasma IDO concentration was markedly increased in HD patients (median 8.04 ng/mL vs. 48.9 ng/mL). Serum IL-6 and CRP were also significantly increased in HD patients. Compared with HD patients without CHD, plasma IDO concentration was significantly increased in HD patients with CHD (median 38.6 ng/mL vs. 74.5 ng/mL). Neither IL-6 nor CRP differed between the last two groups. IDO was negatively correlated with IL-6 and CRP.


CONCLUSIONS
IDO concentration is increased in HD patients and is increased further in HD patients with CHD. It remains to be elucidated if increased IDO plays a direct role in the pathogenesis of atherosclerosis or if it affects atherosclerosis indirectly by curtailing chronic inflammation or both.
Department of Nephrology, Medical School, University of Thessaly, Larissa, Greece. teleftheriadis@yahoo.com
Theodoros
T
Eleftheriadis
Georgia
G
Antoniadi
Vassilios
V
Liakopoulos
Ioannis
I
Stefanidis
Grammati
G
Galaktidou
D002097:C-Reactive Protein / Q000032:analysis; D003327:Coronary Disease / Q000097:blood* / Q000209:etiology*; D006801:Humans; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D008875:Middle Aged; D006435:Renal Dialysis
D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D015850:Interleukin-6; D002097:C-Reactive Protein