Differential effect of hemodialysis membranes on human lymphocyte natural killer function

Lymphocytes exposed to cuprammonium cellulose membranes have been shown to exhibit depressed natural killer (NK) function. In the present study we investigated the extent to which three dialyzer membranes of different compositions suppressed human lymphocyte NK activity. Peripheral blood lymphocytes or T cells from normal donors were exposed in vitro to cuprammonium cellulose, cellulose acetate, or polycarbonate dialyzer membranes. After exposure to the membranes, NK activity of the cells was studied by using the NK-sensitive cell line K562 as targets. All three membranes adversely affected human lymphocyte NK function, with cuprammonium cellulose producing the most (70-80%) and polycarbonate producing the least (10-15%) suppression. Our results suggest that the composition of dialyzer membranes affects the extent to which the membranes impair human lymphocyte function. The use of more biocompatible membranes might lessen the potential clinical impact of abnormal NK function in hemodialysis patients.