Perfusion studies on the formation of mural thrombi with cholesterol-modified and hypercholesterolemic platelets

Using the Baumgartner apparatus, perfusion studies have been carried out with blood from patients with hypercholesterolemia type IIa (n = 5) and IIb (n = 9) and with reconstituted blood containing platelets in which the cholesterol/phospholipid ratio had been modified by incubation with liposomes. With cholesterol-enriched platelets (C/PL 0.869), both platelet adherence and thrombus size were doubled with respect to cholesterol-normal platelets (C/PL 0.587), which in turn had values approximately twice that in cholesterol-depleted platelets (C/PL 0.494), differences statistically significant at p less than 0.02. With blood from patients with hypercholesterolemia, statistically significant values (p less than 0.03) were seen only for increase in adherence of platelets from type IIb patients as compared with controls. These results demonstrate that changes in platelet membrane cholesterol levels can affect interaction with subendothelium in cholesterol-modified platelets but suggest that more restricted differences may occur with platelets from patients with hypercholesterolemia.