Effects of dialyser and dialysate on the acute phase reaction in clinical bicarbonate dialysis

Abstract

Background. In chronic haemodialysis (HD), morbidity may result from repetitive induction of the acute phase response, caused by a bioincompatible dialysis membrane and/or contaminated dialysate. In the present study, cytokine release (interleukin-6, IL-6) and subsequent production of acute phase proteins (C-reactive protein, CRP and secretory phospholipase A2, sPLA2) were assessed to investigate whether the HD-induced acute phase reaction depends mainly on the type of membrane or on the sterility of the dialysate. Methods. In 11 patients, IL-6, CRP and sPLA2 levels were assessed in blood samples drawn before (t0), at the end (t180) and 24 h after the start of HD (t1440). All patients were dialysed on Cuprammonium (CU) and Polysulphon (PS) dialysers and seven patients underwent an additional HD session on CU plus a dialysate filter (CUf). Results. IL-6 levels were increased significantly at t180 compared with t0 (P < 0.02) with both CU and CUf. At t1440, IL-6 levels had returned to baseline. In contrast, marked fluctuations did not occur during HD with PS. At t180 IL-6 was significantly greater with CU and CUf devices, than with PS (P < 0.02). Following HD with CU and CUf, a significant increase in CRP was observed at t1440 compared with postdialysis values (P ≤ 0.05). In addition, sPLA2 values were markedly increased at t1440 compared with t180, but only significant in the case of CV (P = 0.01). IL-6 levels at t180 were significantly correlated with CRP (r = 0.50, P < 0.01) and sPLA2 (r = 0.47, P = 0.01) values at t1440. During HD with PS membranes, neither CRP nor sPLA2 values were markedly changed. Conclusions. In contrast to PS, both CU and CUf resulted in elevated IL-6 plasma levels at the end of HD, compared with t0 which correlated with increased CRP and sPLA2 values 24 h later. Therefore, the type of membrane, rather than the bacterial quality of the dialysate, seems to be responsible for the induction of the acute phase response during clinical bicarbonate HD.