BACKGROUND: Immunological dysfunction in patients on haemodialysis may be related to imbalanced cytokine systems, such as tumour necrosis factor (TNF)-alpha and interleukin (IL)-2. Despite activation of these systems, haemodialysis patients show high susceptibility for infections and malignancies, and have a poor immunological reaction to T-cell-dependent antigens, like hepatitis B vaccination. In this study we have determined the activation status of the two different cytokine systems, at the single cell level, using quantitative flow cytometry. METHODS: Using fluorescein isothiocyanate- or phycoerythrin-conjugated antibodies directed against TNF-R2 (CD120b), IL-2Ralpha (CD25) and IL-2Rbeta (CD122), we measured the expression of these receptors at the single cell level in order to determine the level of activation of monocytes and T-lymphocytes. RESULTS: Significantly higher expression of the TNF-alpha receptor, TNF-R2, was present on both monocytes and T-lymphocytes in patients on renal replacement therapy (RRT) compared with pre-dialysis chronic renal failure (CRF) patients and controls, indicating activation of the TNF-alpha system. In contrast, IL-2R expression was comparable in all groups studied, which may reflect a non-activated state of the IL-2 system. CONCLUSIONS: The present study illustrates an activated state of the TNF-alpha system in patients on RRT, at the single cell level, while the IL-2 system seems to be unaffected. These findings support the hypothesis that the interaction between the TNF-alpha and IL-2 cytokine systems is disturbed.

*Peritoneal Dialysis, Continuous Ambulatory, *Renal Dialysis, Adult, Antigens, CD/*blood, Biological Markers/blood, Calibration, Comparative Study, Continental Population Groups, Female, Flow Cytometry/methods, Humans, Kidney Failure, Chronic/blood/*immunology/therapy, Lymphocyte Activation, Male, Middle aged, Monocytes/*immunology, Netherlands, Protein Isoforms/blood, Receptors, Interleukin-2/*blood, Receptors, Tumor Necrosis Factor, Type II, Receptors, Tumor Necrosis Factor/*blood, Reference Values, T-Lymphocytes/*immunology
hdl.handle.net/1765/9664
Nephrology, Dialysis, Transplantation
Erasmus MC: University Medical Center Rotterdam

Baan, C.C, Knoop, C, Loonen, E.H.M, Zietse, R, Weimar, W, & van Riemsdijk-van Overbeeke, I.C. (2001). Quantitative flow cytometry shows activation of the TNF-alpha system but not of the IL-2 system at the single cell level in renal replacement therapy. Nephrology, Dialysis, Transplantation. Retrieved from http://hdl.handle.net/1765/9664