The cholesterol/phospholipid ratio of the erythrocyte membrane in children with familial hypercholesterolemia. Its relationship with plasma lipids and red blood cell aggregability.

The cholesterol/phospholipid ratio (C/PL) of the red blood cell membrane, plasma lipids and erythrocyte aggregability were evaluated in 20 children with familial hypercholesterolemia (age: 10.4+/-4.6 years) but without detectable vascular injury. The results indicate that hypercholesterolemic children have a higher erythrocyte membrane C/PL ratio than the control group (0.81+/-0.23 vs. 0.65+/-0.08, p < 0.01). This membrane lipid alteration correlates inversely with the plasma concentration of HDL-cholesterol (r = -0.558, p < 0.010). The patients also showed greater erythrocyte aggregability than the control group (8.21+/-1.11 vs. 6.25+/-1.24, p < 0.001), but this does not seem to correlate with the changes observed in the lipid composition of the cell membrane. These results suggest that from childhood, people with familial hyper-cholesterolemia show alterations in the lipid composition of the red blood cell membrane that are related to the changes observed in plasma lipids and appear prior to atherosclerotic vascular symptoms.