Effects of a medium cut-off (Theranova®) dialyser on haemodialysis patients: a prospective, cross-over study

Background. Despite significant advances in haemodialysis (HD) in recent decades, current dialysis techniques are limited by inadequate removal of uraemic solutes such as middle molecules and protein-bound uraemic toxins. Novel medium cut-off (MCO) membrane or 'expanded haemodialysis' (HDx) provides diffusive removal of conventional and large middle molecular weight uraemic toxins, with marginal albumin leak. Methods. This prospective, open-label, controlled, cross-over pilot study compared HDx (novel MCO membrane Theranova (R) 400) and conventional HD in 20 prevalent HD patients. Biochemical, dialysis adequacy and safety measures (adverse events, infections and hospitalization frequency) were recorded. Ten patients underwent conventional HD high-flux dialyser and 10 patients underwent HDx for 3 months, and the patients then switched and received the other treatment for a further 3 months. Results. Treatment with HDx was associated with a significant reduction in serum albumin concentration [median (interquartile range) reduction -0.45 g/dL (-0.575 to -0.05); P=0.025]. However, median albumin levels were >= 3.5 g/dL and no patients had clinical symptoms of hypoalbuminaemia or needed intravenous albumin administration. The number of infections was lower in patients treated with HDx (n=7/19) compared with patients treated with HD (n=14/20; P=0.03). Patients treated with HDx had reduced levels of interleukin (IL)-1 beta (from 0.060.02 pg/mL versus 0.28 +/- 0.18 pg/mL with HD) and IL-6 (6.45 +/- 1.57 pg/mL versus 9.48 +/- 2.15 pg/mL), while tumour necrosis factor-alpha levels remain unchanged. Conclusions. This study demonstrates that the chronic use of the novel MCO dialyser Theranova (R) appears to be safe and well-tolerated, without serious side effects or hypoalbuminaemia, as well as fewer infections. These results need to be confirmed in larger randomized clinical trials.