Studies on red cell flexibility in spherocytosis using a polycarbonate membrane filtration method.

A method for studying red cell flexibility as reflected by red cell rigidity and fragility is described. Using an infusion pump, suspended red cells are filtered through a polycarbonate membrane with 3 micron pores. The filtration pressure, which is continuously monitored, is considered to reflect red cell rigidity. The hemoglobin released by the disruption of red cells passing through the membrane is regarded as an indirect measure of red cell fragility. In all of the patients with hereditary spherocytosis studied and in some of their symptomless relatives, the decreased flexibility observed was associable with increased rigidity of the red cell. In vitro effects of chlorpromazine and vinca alkaloid on red cell flexibility were also studied. High concentrations of chlorpromazine and vinblastine induced formation of spherocytes displaying altered cell flexibility.