Effects of hemodialysis on activation of lymphocytes: analysis by an in vitro dialysis model

Patients undergoing maintenance hemodialysis have impaired immune responsiveness, which appears to deteriorate progressively with the duration of the replacement treatment. It has been suggested that it is caused by a chronic preactivation state of T cells caused by hemodialysis. Each treatment session has been compared with a recurring "acute-phase" inflammatory reaction. In this study, the acute effects of hemodialysis on the activation state and functional responsiveness of normal peripheral blood mononuclear cells have been evaluated by use of an in vitro dialysis model. The dialysis was carried out with either cuprophan or polysulfone membranes, with or without sodium acetate in the dialysis fluid. It was observed that a single session of in vitro dialysis did not induce production of interleukin-2 (IL-2) and did not alter the expression of IL-2 receptor (IL-2R) on the cytoplasmic membrane and the secretion of soluble IL-2R, whereas it induced transcription of mRNA for IL-2R. The proliferative response of lymphocytes to phytohemagglutinin or IL-2 in vitro also did not change after a single dialysis session. There was only a slight decrease of the release of soluble IL-2 receptor by phytohemagglutinin-stimulated cells after dialysis. Dialysis induced an active synthesis of IL-1 by peripheral blood mononuclear cells, even in the absence of sodium acetate in the dialysate bath, but there was no release of IL-1 to the circulating medium. The results show that a single dialysis encounter can acutely prime the activation of human peripheral blood mononuclear cells.(ABSTRACT TRUNCATED AT 250 WORDS)