Erythrocyte lipid composition and sodium transport in human liver disease.

In patients with liver disease there are usually increases in erythrocyte cholesterol and phosphatidylcholine concentrations. This increase in membrane lipid changes the shape of the erythrocyte and "spur" or "target" cells may be present. Sodium fluxes were measured in erythrocytes from 17 patients with a variety of liver diseases and from 17 normal subjects and the values related to the lipid content of the membrane. Ouabain-insensitive and ouabain-sensitive effluxes were lower in patients than in normal subjects and the reduction in ouabain-insensitive efflux was more marked. Sodium influx was also significantly lower in erythrocytes from patients than controls. Ouabain-sensitive and ouabain-insensitive effluxes and sodium influx did not correlate with the cholesterol content of erythrocytes from patients. Significant negative correlations were noted between ouabain-insensitive sodium efflux (r=--0.63, P less than 0.01), sodium influx (r=--0.61, P less than 0.01) and intracellular sodium concentration (r=--0.66, P less than 0.01) and the cholesterol : phospholipid molar ratio of the cell but there was no significant correlation between this ratio and the ouabain-sensitive sodium efflux (r=0.41, P less than 0.05). These results support the hypothesis that an altered lipid composition may affect the permeability of the erythrocyte membrane in patients with liver disease.