Pulsed flow cascade filtration. Long-term experience in low density lipoprotein and lipoprotein a removal

The authors present the results of pulsed flow cascade filtration (PFCF) for low density lipoprotein (LDL) and lipoprolein a (La) removal in four patients with familial hypercholesterolemia. Forty-six treatments were performed. Pressure and flow pulsations were superimposed on the retentate of the secondary filter using a modified single roller peristaltic pump. The pulsation frequency was adjusted to achieve, on average, zero retentate flow (dead end filtration). The transmembrane pressure and sieving coefficients of immunoglobulin G, apolipoprotein A1, and apolipoprotein B of the secondary filter remained constant during filtration periods of 150 min. The PFCF technique was found to remove more LDL and La than did adsorption on dextran sulfate columns, while maintaining adequate albumin recovery (90%).