Effect of renal dialysis therapy modality on T cell cytokine production

Introduction. Dialysis has been associated with acute changes in the comple ment activation status, granulocyte markers, macrophage function, T cell ac tivation and the release of pro-inflammatory cytokines. The most common ana lysis of cytokine production in patients on dialysis has focused on the cha nges in monokines (particularly IL-1 and TNF alpha), however it is becoming clear that T cell cytokines play a major role in the impaired lymphocyte f unction of dialysis patients. Methods. To assess the effect of dialysis modality on T cell function we an alysed the ability of T cells within peripheral blood mononuclear cell popu lations (PBMC) to produce cytokines after mitogen (phorbol-12-myristate-13- acetate; PMA and Ionomycin; I) stimulation in patients on peritoneal dialys is (PD) compared to low flux haemodialysis (HD) and normal individuals (con trols). Results. In control PBMC, PMA+I stimulation significantly increased the per centage of CD3(+) cells expressing IL-2, IFN gamma, TNF alpha, IL-4 and IL- 10, as expected. However, although mitogen stimulation significantly enhanc ed the percentage of the classical Th1 cytokines (IL-2, IFN gamma and TNF a lpha) in the low flux HD PBMC, it had no effect on CD3(+) IL-2 or CD3(+) TN F alpha producing cells in the PD group. In contrast, the percentage of T c ells producing Th2 cytokines (IL-4 and IL-10) could not be consistently enh anced by mitogen in either dialysis group. Conclusions. We suggest that PD alters the ability of T cells to produce cy tokines, possibly by causing an 'exhaustion' of the Th1 cells, thereby prev enting cells to produce cytokine on ex vivo stimulation Furthermore, since T cells from both low flux HD and PD groups could not be induced to produce Th2 cytokines we suggest that uraemia or dialysis per se inhibits T cells from producing Th2 cytokines.