This study was performed in 97 hemodialysis patients (85 on HD and 12 on CAPD) to investigate the possible correlation between B2-m and hemodialysis-related amyloidosis syndromes (HRA-S); differences in B2-m and HRA behavior between patients hemodialysed with cellulose and synthetic membranes were also included in the present study. Data indicate that B2-m levels are not correlated with dialysis length or with the type of membrane used for the dialysis. On the contrary, in 16 patients with the Carpal Tunnel Syndrome, a significant correlation was found between the CTS, the dialysis length and the type of membrane (greater incidence with cellulosic membranes).