Background: Morbidity in haemodialysis patients is associated with chronic inflammation. Microbiological contaminants derived from dialysate are thought to be one inflammatory stimulus and previous studies found that highly purified dialysate reduces inflammation and morbidity. These studies were performed in the absence of practices, such as dialyser reuse, that are potentially inflammatory. We tested the hypothesis that highly purified dialysate reduces inflammation and morbidity even in the presence of other inflammatory stimuli.
Methods: This was a prospective observational study. After obtaining baseline data on inflammation, oxidant stress, nutrition and anaemia correction with standard dialysate, 105 patients were switched to dialysate that was ultrafiltered at the point of use and follow-up data were collected at 3-month intervals for 12 months.
Results: Introduction of ultrafiltered dialysate did not significantly reduce inflammation, as assessed by plasma concentrations of C-reactive protein and interleukin-6 or oxidant stress, as assessed by plasma concentrations of protein carbonyls and protein-free sulphydryls. Neither did it improve anaemia correction, as assessed by plasma haemoglobin and erythropoietin dose. However, introduction of ultrafiltered dialysate was associated with a significant reduction in plasma beta(2)-microglobulin concentration and a significant improvement in nutritional status, assessed by plasma albumin concentration and creatinine generation rate as a marker of muscle mass.
Conclusion: Use of ultrafiltered dialysate was associated with improvements in some measures of morbidity, such as plasma beta(2)-microglubulin and nutrition. These changes occurred in spite of the presence of inflammatory stimuli, such as dialyser reuse, and with no measurable reduction in inflammation and oxidant stress.