Impairment of blood rheology by cholestatic jaundice in human beings

Bilirubin and bile acids may affect erythrocytes. We investigated blood viscosity and erythrocyte structure in patients with cholestatic jaundice ex vivo and studied the short-term effects of bilirubin and bile acids in vitro. Seventeen patients with cholestatic jaundice and controls were studied. Whole-blood viscosity (adjusted hematocrit 45%) at high (94.5 sec(-1)) and low (0.1 sec(-1)) shear rate and plasma viscosity were measured. Erythrocyte structure was assessed in wet preparations of fixed cells. In vitro whole blood was incubated with increasing concentrations of bilirubin (83% conjugated) and bile acids (cholic, lithocholic, deoxycholic, and chenodeoxycholic acid) and the abovementioned investigations were performed. In patients we observed increased whole-blood viscosity at high shear rate (5.82 +/- 0.69 vs 5.04 +/- 0.27 mPa . sec, P = .0001), plasma viscosity (1.48 +/- 0.22 vs. 1.23 +/- 0.07 mPa . sec, P = .0004), and fibrinogen level (4.70 +/- 0.98 g/L vs 2.63 +/- 0.21 g/L, P < 0.001) were observed. The incubation of normal erythrocytes in patients' plasma confirmed an increase in blood viscosity at high shear rate. Erythrocytes from patients with jaundice demonstrated a slight degree of stomatocytic shape transformation (P <.0001). In vitro, bilirubin did not affect erythrocyte shape. Cholic and lithocholic acids caused a slight stomatocytic shape transformation, whereas deoxycholic acid and chenodeoxycholic acid influenced neither blood viscosity nor erythrocyte structure. Patients with cholestatic jaundice have increased whole-blood and plasma viscosity and slightly altered red blood cell shape, possibly the result of a combination of increased levels of bilirubin and bile acids plus an acute-phase reaction.