Are all polysulfone-based dialyzers equally efficient in removing high molecular weight uremic toxins

The target of modern dialyzers is to maximize the permeability of small and middle molecular weight (MW) toxins while retaining albumin. Reduction ratio (RR) of small water-soluble compounds like urea and middle MW molecules like β2 microglobulin are well studied for each dialysis membrane. Differences in clearance of substances with higher MW are less known. Based on higher Stokes' radius and MW, we measured myoglobin RR as a surrogate for uremic toxins with higher MW.