Garcia-Prieto A, et al. - The effectiveness of a medium cut-off (MCO) dialyser in the removal of small and medium-size molecules was determined and, it was compared with standard high-flux (HF) dialysers in haemodialysis (HD) and online haemodiafiltration (OL-HDF). Compared with standard HF HD, MCO HD showed superior efficacy in the removal of middle and larger middle molecules. Also, in the clearance of small and larger middle molecules, MCO HD was no inferior to OL-HDF. Therefore, it could be an alternative in patients in which it is not possible to perform OL-HDF.