Plasma indoleamine 2,3-dioxygenase and arginase type I may contribute to decreased blood T-cell count in hemodialysis patients.
BACKGROUND
Acquired immunity is impaired in hemodialysis (HD) patients, and decreased T-cell number may contribute. Indoleamine 2,3-dioxygenase (IDO) and arginase type I (ARG) catabolize tryptophane and arginine, respectively, and exert proapoptotic and antiproliferative effects on T-cells. Plasma levels of IDO and ARG and their relation to blood T-cell number were evaluated in HD patients.


METHODS
Thirty-two HD patients and 20 healthy controls participated in the study. Plasma IDO and ARG were measured by means of enzyme-linked immunosorbent assay. T-cell number was assessed by means of flow cytometry.


RESULTS
IDO concentration was significantly higher in HD patients than in healthy volunteers (44.30 ± 31.83 ng/mL vs. 21.28 ± 26.21 ng/mL, p = 0.009). There was a trend for higher ARG concentration in HD patients (13.43 ± 11.91 ng/mL) than in healthy volunteers (9.56 ± 4.03 ng/mL), which, however, did not reach statistic significance (p = 0.099). Absolute T-cell count was significantly lower in HD patients than in healthy controls (1176.99 ± 567.71 cells/mm3 vs. 1519.85 ± 594.96 cells/mm3, p = 0.040). Absolute blood T-cell number was inversely related to plasma IDO (r = -0.490, p = 0.004) and to plasma ARG (r = -0.387, p = 0.029) concentrations.


CONCLUSIONS
Plasma IDO and ARG may contribute to decreased blood T-cell count in HD patients.
Department of Nephrology, Medical School, University of Thessaly, Larissa, Greece. teleftheriadis@yahoo.com
Theodoros
T
Eleftheriadis
Efi
E
Yiannaki
Georgia
G
Antoniadi
Vassilios
V
Liakopoulos
Georgios
G
Pissas
Grammati
G
Galaktidou
Ioannis
I
Stefanidis
D056704:Adaptive Immunity; D017209:Apoptosis; D001119:Arginase / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006801:Humans; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000276:immunology / Q000628:therapy; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D006435:Renal Dialysis; D013601:T-Lymphocytes / Q000473:pathology*
D015415:Biomarkers; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; C574619:ARG1 protein, human; D001119:Arginase