Plasma exchange and low-density lipoprotein filtration therapy in heterozygous familial hypercholesterolemia

We studied serum lipids during and shortly after a single plasma exchange (PE) on seven separate occasions in four patients, and during long-term treatment by regular PE in three patients with heterozygous familial hypercholesterolemia. Also, a comparison was made for efficacy in lipid and apolipoprotein removal between long-term weekly PE therapy and three consecutive weekly low-density lipoprotein (LDL) filtration procedures in one patient. PE was done by intermittentflow centrifugation (IFC) with Haemonetics V50 apparatus, exchanging one plasma volume. LDL filtration consisted of a cascade PE, in which the plasma was separated by IFC and the LDL fraction was subsequently removed by membrane filtration over a polyalcohol filter (Evaflux^®). From the results, we concluded that (1) LDL cholesterol is reduced about 50% by both methods; (2) after PE, high-density lipoprotein (HDL) cholesterol does not increase during the first two hours, but rises thereafter faster than LDL cholesterol and can reach baseline within three days; (3) by LDL filtration, HDL cholesterol decreases about 30% less than LDL cholesterol and tends to increase above the starting levels found during weekly PE treatment; (4) the reductions in LDL and HDL cholesterol are larger than those in apolipoprotein B and A-I, respectively, in both methods; and (5) connection of the LDL filter device to the Haemonetics V50 system simplifies the cascade procedure, resulting in a single needle approach and avoidance of hemolysis in the primary plasma separation.