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(®) 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)-1β (from 0.06 ± 0.02 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-α levels remain unchanged. CONCLUSIONS: This study demonstrates that the chronic use of the novel MCO dialyser Theranova(®) 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.