CHOLESTEROL-LOWERING TREATMENT IN PATIENTS WITH FAMILIAL DEFECTIVE APOLIPOPROTEIN-B-100

Familial defective apolipoprotein B 100 (FDB) is caused by a single amino acid substitution (Arg3500 to Gln) of the apolipoprotein B 100 which disrupts the binding of low density lipoprotein (LDL) particles to the LDL receptor. We found this mutation in 5% of our patients with isolated LDL-cholesterol elevation. The effect of lovastatin and simvastatin alone and in combination with colestyramine was studied in 12 patients with FDB. The LDL cholesterol fell in response to lovastatin and simvastatin by a mean of 26%, ranging from 10% to 47%. Additional decreases were observed in combination with colestyramine. In 3 of 6 patients treated with the combination of statins and colestyramine the LDL-cholesterol reduction was greater than 50%. These results were compared with a group of patients clinically diagnosed as heterozygous familial hypercholesterolemia. The mean % reduction of LDL cholesterol was similar in the two groups. This indicates, that in patients with FDB the response to treatment with statins and colestyramine is not different from patients with hypercholesterolemia of other causes.