VWF and anemia: Platelet-vessel wall interaction • ↓ GPIb platelet receptors • Competitive binding of uremic toxin to αIIbβ3 → reduced binding to fibrinogen • Functional defect VWF-platelet interaction related to uremic toxins • Inhibition platelet aggregation by vasoactive substances: ↑NO production by platelets • ↓ in anemia (less scavenging of NO by haemoglobin)