Use of Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry to Demonstrate Decreased Serum Statin Levels after Extracorporeal LDL-Cholesterol Elimination

Background. Using our statin analysis method, it was possible to uncover a significant drop in statin levels (atorvastatin, simvastatin, and metabolites) after extracorporeal LDL-cholesterol elimination (EE) in severe familial hypercholesterolemia (FH). The purpose of this work was to identify the mechanism underlying this drop and its clinical significance as well as to propose measures to optimize a pharmacotherapeutical regimen that can prevent the loss of statins. Methods. Ultra High Performance Liquid Chromatography (UHPLC) connected to the triple quadrupole MS/MS system was used. Patients. A group of long-term treated patients (3–12 years of treatment) with severe FH (12 patients) and treated regularly by LDL-apheresis (immunoadsorption) or haemorheopheresis (cascade filtration) were included in this study. Results. After EE, the level of statins and their metabolites decreased (atorvastatin before/after LDL-apheresis: 8.83/3.46 nmol/l; before/after haemorheopheresis: 37.02/18.94 nmol/l). A specific loss was found (concentration of atorvastatin for LDL-apheresis/haemorheopheresis: 0.28/3.04 nmol/l in washing fluids; 11.07 nmol/l in filters). To prevent substantial loss of statin concentrations, a pharmacotherapeutic regimen with a longer time interval between the dose of statins and EE is recommended (15 hours). Conclusions. A specific loss of statins was found in adsorbent columns and filters. The decrease can be prevented by the suggested dosage scheme.