von Willebrand factor binding to collagen in patients with end-stage renal disease.

Bleeding abnormalities are common in patients with end-stage renal disease (ESRD). Although von Willebrand factor (vWF) abnormalities have been suspected in patients with ESRD, none have been clearly defined. Because vWF function is related to its collagen-binding capacity, we investigated whether this parameter might be altered in patients with ESRD. We measured vWF binding to type III collagen and levels of vWF antigen and ristocetin cofactor in 20 patients undergoing hemodialysis before and after routine hemodialysis sessions, in 10 patients with ESRD who had not previously undergone dialysis, and in 22 healthy, nonsmoking persons who served as controls. We found significant increases of vWF antigen levels in all patients with ESRD (undialyzed: mean, 6.4 +/- 3.0 U/ml, p < 0.001; before dialysis: mean, 5.1 +/- 4.0 U/ml, p < 0.001; after dialysis: mean, 4.8 +/- 3.4 U/ml, versus 0.81 +/- 0.26 U/ml in controls, p < 0.001). The ristocetin cofactor levels were increased in the patients who had not undergone dialysis (mean, 1.30 +/- 1.26 U/ml, p = 0.04), whereas both before and after hemodialysis groups (means, 0.71 U/ml and 0.75 U/ml, respectively) were not significantly different from controls (mean, 0.72 +/- 0.30 U/ml, p = 0.96 and p = 0.8, respectively). Patients with ESRD who had not undergone dialysis showed no difference in vWF binding to collagen (mean, 1.21 +/- 0.63 U/ml) compared with the control group (mean, 1.16 +/- 0.13).(ABSTRACT TRUNCATED AT 250 WORDS)