Analysis of low density lipoprotein apheresis: post-treatment rebound using mathematical models.
Double membrane low density lipoprotein (LDL) apheresis (thermofiltration) was applied to treat six hyperlipidaemic patients and five controls 14 and 5 times, respectively, and post-treatment plasma LDL cholesterol (LDLc) concentration rebound was measured. To simulate the rebound, a nonlinear model (NLM) was developed. It consists of two compartments representing plasma and liver. LDLc uptake by the liver is described by receptor-independent and by receptor-mediated transport as controlled by the liver cholesterol concentration. NLM analysis of patient data resulted in pre-treatment fractional catabolic rate (FCR) for LDLc of 0.19 day-1 and the maximum FCR for LDLc of 0.26 day-1 on the 4th day. NLM showed that in patients and controls the post-treatment LDL synthesis rate rose by 6% to 15%. The steady-state (kinetic) version of this model was used to develop a formula describing the relationship between the FCR for LDLc and blood plasma LDLc concentration which agrees well with published data.
Werynski
A
A
Institute of Biocybernetics and Biomedical Engineering PAS, Warsaw, Poland.
Malchesky
P S
PS
Nomura
H
H
Nose
Y
Y
D000328:Adult; D000368:Aged; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000378:metabolism*; D003198:Computer Simulation; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000378:metabolism* / Q000628:therapy; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010956:Plasmapheresis; D011973:Receptors, LDL / Q000378:metabolism; D012984:Software
D008078:Cholesterol, LDL; D011973:Receptors, LDL; D002784:Cholesterol