Optimization of the therapeutic procedure during LDL-apheresis--a computerized model

LDL-apheresis is a very effective method for the treatment of resistant hypercholesterolemia when other therapy (dietary, or medication) fails. To maximize the efficacy of the LDL-absorbers we aimed to create a computerized model.

The therapeutic technique of immunoadsorption was used, applying a pair of columns, the Lipopak, Pocard, Russia. Plasma was separated by a continuous-flow plasma separator, the Cobe Spectra, USA; adsorption was controlled by adsorption-desorption equipment, ADA, Medicap, Germany. 494 LDL-apheresis procedures (treatment interval 17.5+/-1.6 days) were used to treat nine patients with primary hypercholesterolemia followed during the consecutive 3.6+/-0.5 years. Metabolism of LDL-cholesterol is known to be multicompartmental and dynamic, but for the short-time period of the procedure it can be simplified and one can calculate the procedure as a continuous filtration. We developed a program for procedure planning, using Microsoft Excel for Windows. Inputs inserted into the program include only basic patient data (mass, height, sex and initial plasma LDL level in mmol/l).

The results show a very promising match between our planning of the procedures and the real laboratory results. The drop in calculated vs real plasma LDL-cholesterol level differ no more than +/-10%.

Although our software does not take into account many well known details about the metabolism of cholesterol, in given conditions it can provide a fairly precise prediction of procedure parameters. It is also suitable for practical use, because it requires only a few commonly used and readily available input values. Immunoadsorption with Pocard absorbers is a potent and safe method of therapy in indicated patients.