The effects of hemodialysis with different membranes on middle molecules and uremic neuropathy.

Twenty-four hemodialysis patients, 14 with uremic neuropathy and 10 symptom-free, were studied over 12 months. Cuprophan and AN 69 membrane dialyzers were used in their treatment in order to investigate the influence of different membranes on plasma levels of middle molecular weight substances (MMS) and uremic neuropathy. Hemodialysis with the cuprophan membrane caused no significant changes in plasma MMS levels or in the neurological condition of patients. The effect of dialysis with AN 69 membrane depended on initial plasma MMS levels. Initially high plasma MMS levels decreased significantly and significant improvement of neuropathy was achieved. In neuropathic patients with plasma MMS levels similar to those of symptom-free patients, hemodialysis with AN 69 membrane had no effect. These results suggest that hemodialysis with MMS high-permeability membranes may be recommended for neuropathic patients with high plasma MMS levels.