[What is the reason for the increase in beta-2-microglobulin levels in the blood when using cuprophane dialysis membranes?].

The authors discuss the question of whether the growing blood concentration of beta-2-microglobulin in the course of haemodialysis is due to the bioincompatibility of the cuprophane membrane or to changes in serum osmolality. x531p4cuprophane dialyzer was used for 20 acts of haemodialysis, a regenerated one for 12, a new one for 10 sequence ultrafiltrations. The serum concentration of beta-2-microglobulin was measured prior to and after haemodialysis, and so was serum osmolality. The changes in beta-2-microglobulin concentration during haemodialysis were compared with serum osmolality changes. The levels of beta-2-microglobulin rose during haemodialysis using a new as well as a regenerated dialyzer but remained unaltered during sequence ultrafiltration. They increased in the presence of serum hypoosmolality, remained unchanged in normal osmolality, and decreased in hyperosmolality. The results show that the cuprophane membrane is not the source of increased beta-2-microglobulin, but that serum hypoosmolality developing during haemodialysis is the factor responsible.