Long-term changes in cholesterol biosynthesis and the effect of plasmapheresis therapy in a hypercholesterolemia homozygote.

Synthesis of cholesterol was measured in a familial hypercholesterolemia homozygote on four occasions from age 1.1 to 9.9 years by the sterol balance technique. Both the fecal neutral steroid and fecal bile acid components of sterol balance were elevated initially. Over the decade of study, neutral steroid excretion/kg declined 61% whereas bile acid excretion/kg was unchanged. Chronic plasmapheresis therapy every two weeks for 3.4 years reduced plasma low-density lipoprotein cholesterol 54% but had little effect on the rate of cholesterol biosynthesis.