Dual size-exclusion chromatography for efficient isolation of extracellular vesicles from bone marrow derived human plasma.

Isolation of pure extracellular vesicles (EVs), especially from blood, has been a major challenge in the field of EV research. The presence of lipoproteins and soluble proteins often hinders the isolation of high purity EVs upon utilization of conventional separation methods. To circumvent such problems, we designed a single-step dual size-exclusion chromatography (dSEC) column for effective isolation of highly pure EVs from bone marrow derived human plasma. With an aim to select appropriate column design parameters, we analyzed the physiochemical properties of the major substances in bone marrow derived plasma, which include EVs, lipoproteins, and soluble proteins. Based on these findings, we devised a novel dSEC column with two different types of porous beads sequentially stacked each other for efficient separation of EVs from other contaminants. The newly developed dSEC columns exhibited better performance in isolating highly pure EVs from AML plasma in comparison to conventional isolation methods.

Cholesterol removal from human plasma with biologically modified cryogels.

In this study, low molecular weight heparin immobilized P(HEMA) cryogels were fabricated for the removal of LDL-C in hypercholesterolemic human plasma. After characterization studies for P(HEMA) cryogels, effects of the parameters including medium pH, CNBr concentration, heparin concentration and contact time on heparin immobilization were investigated. Blood compatibility and cell adhesion tests were also performed, and platelet and leucocyte loss for P(HEMA)-Hp cryogels were found to be 2.95% and 4.91%, respectively. Maximum adsorption capacity for LDL-C from hypercholesterolemic human plasma was found to be 26.7 mg/g for P(HEMA)-Hp cryogel while it was only 1.67 mg/g for bare P(HEMA) cryogel. The P(HEMA)-Hp cryogels exhibit high desorption ratios up to 96% after 10 adsorption-desorption cycles with no significant decrease in the adsorption capacity. The findings indicated that these reusable P(HEMA)-based cryogels proposed good alternative adsorbents for removal of LDL-C.

Real-world study: Escalating targeted lipid-lowering treatment with PCSK9-inhibitors and lipoprotein apheresis.

INTRODUCTION: Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition with monoclonal antibodies has complemented the armamentarium of lipid-lowering therapy (LLT) before the final step of commencing chronic lipoprotein apheresis (LA). Data are scarce on patients who, after escalation of LLT with PCSK9 antibodies, have commenced chronic LA or PCSK9 antibody treatment during ongoing long-term LA. PATIENTS AND METHODS: In this study, a cohort of 110 patients with established atherosclerotic cardiovascular disease (ASCVD) due to hypercholesterolemia or concomitant lipoprotein(a)-hyperlipoproteinemia, who received PCSK9 antibodies for the first time during routine care, were consecutively identified. RESULTS: Mean LDL-C concentration prior to initiation of LA or PCSK9 antibody treatment was 5.3 ± 2.6 mmol/L (205 ± 102 mg/dL). Due to established ASCVD, the risk-adjusted LDL-C target value was <1.8 mmol/L (<70 mg/dL) in all patients. Use of PCSK9 antibodies increased the proportion of patients attaining the LDL-C target concentration by 41.8% overall. Treatment emergent adverse events (TEAE) associated with PCSK9 antibody medication were reported in 35 patients (31.8%). Discontinuation of PCSK9 antibody therapy due to TEAEs occurred in 25 patients (22.7%). CONCLUSION: Finally, 55.5% of patients received a combination of PCSK9 antibody therapy and LA at individually optimized treatment frequencies resulting in an increase of target attainment in 54.1% of patients. About 18.1% of chronic LA patients terminated LA treatment in this real-world study. The termination of long-term LA therapy, which has hitherto prevented the progression of ASCVD, requires careful individual risk assessment and cannot be recommended by the general criteria of LDL-C reduction.

New modified Friedewald formulae for estimating low-density lipoprotein cholesterol according to triglyceride levels: extraction and validation.

PURPOSE: The most commonly used method for estimating low-density lipoprotein cholesterol (LDLC) is Friedewald formula (FF). This study aims to extract and validate new modified Friedewald formulae for estimating LDLC according to triglyceride (TG) levels in Iranians. METHODS: Total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), LDLC, and TG were measured in 5030 fasted subjects. The original FF was used for estimating LDLC. Data were divided into training and validation data sets. For extracting modified Friedewald formulae, linear regression was used with TG as independent and TC, HDLC, and directly measured LDLC (D-LDLC) as dependent variables, respectively. An overall modified formula was extracted for TG concentrations <400 mg/dL. The specific modified formulae were extracted for different TG categories. The performance of the modified formulae was assessed in the validation data set. RESULTS: The overall derived formula for calculating LDLC was M-LDLC = TC-HDLC-TG/4. The coefficients of TG (specific TG terms) in modified formulae were 2.7, 3.7, 4.6, and 5 for TG <100, 100-200, 200-300, and 300-400 mg/dL, respectively. Compared to the original FF, applying a new modified formula with TG/4 to a validation data set provided a less mean difference (4.03 vs. 10.86 mg/dL), greater kappa coefficient (0.691 vs. 0.505), and better subject classification (80.8 vs. 67.1%). After applying modified formulae with specific TG terms, the difference between M-LDLC and D-LDLC decreased to 1.41 mg/dL. CONCLUSIONS: Modified formulae were developed and validated for LDLC estimation that compared to the original FF, provided more accurate estimation of LDLC and better classification of subjects. These findings shall be useful for preventive, diagnostic, and therapeutic purposes.

Evolocumab and lipoprotein apheresis combination therapy may have synergic effects to reduce low-density lipoprotein cholesterol levels in heterozygous familial hypercholesterolemia: A case report.

A 49 years old woman (weight 68 kg, BMI 27.3 kg/m2 ) with heterozygous familial hypercholesterolemia (HeFH) and multiple statin intolerance with muscle aches and creatine kinase elevation, presented at the Outpatient Lipid Clinic of Verona University Hospital in May 2015. Hypercholesterolemia was firstly diagnosed during adolescence, followed in adulthood by a diagnosis of Cogan's syndrome, a rheumatologic disorder characterized by corneal and inner ear inflammation. No xanthomas, corneal arcus, or vascular bruits were detectable at physical examination. Screening for macrovascular complications did not reveal relevant damages. Ongoing medical therapy included salicylic acid, methylprednisolone, methotrexate, and protonic-pump inhibitor. In the absence of specific lipid-lowering therapy, plasma lipid levels at first visit were: total-cholesterol = 522 mg/dL, LDL-cholesterol = 434 mg/dL, HDL-cholesterol = 84 mg/dL, triglycerides = 120 mg/dL, Lp(a) = 13 mg/dL. On December 2015, evolocumab 140 mg sc every 2 weeks was initiated. After a 24-week treatment, the LDL-cholesterol levels decreased by an average of 21.2% to 342 ± 22 mg/dL (mean ± SD). On May 2016, LDL-apheresis (H.E.L.P.system) was started as add-on therapy. Compared to the average levels obtained during the evolocumab monotherapy period, the LDL-cholesterol was reduced by 49.4%, thus reaching an inter-apheresis level (mean ± SD) of 173 ± 37 mg/dL. This report suggests that a combination therapy with evolocumab and lipoprotein-apheresis may have synergic effects on circulating lipid levels. Its relevance as a highly effective treatment option for hyperlipidemia in HeFH patients warrants further investigation in larger datasets.

Rationale and study design of a clinical trial to assess the effects of LDL apheresis on proteinuria in diabetic patients with severe proteinuria and dyslipidemia.

BACKGROUND: Diabetic nephropathy is a leading cause of end-stage kidney disease in the world. Although various types of treatment for diabetes, hypertension and dyslipidemia have improved prognosis and quality of life in patients with diabetic nephropathy, there still exist some diabetic patients with severe proteinuria showing poor prognosis. This clinical trial, LICENSE, aims to confirm the impact of LDL apheresis on proteinuria exhibiting hyporesponsiveness to treatment. METHODS: This ongoing trial is a multicenter, prospective study of diabetic patients with severe proteinuria. The objective is to examine the impact of LDL apheresis on proteinuria in patients with diabetic nephropathy. The other subject is to investigate safety of LDL apheresis in these patients. RESULTS: The subjects consist of diabetic patients with serum creatinine (Cr) levels below 2 mg/dL who present severe proteinuria above 3 g/g Cr or 3 g/day and LDL cholesterol above 120 mg/dL. The target number of registered patients will be 35 patients. Urinary protein excretion and renal function will be observed for 24 weeks after the treatment of LDL apheresis. CONCLUSION: This study will determine the effectiveness and safety of LDL apheresis for diabetic nephropathy patients with severe proteinuria and dyslipidemia.

Dislipemia aterógena: una entidad que no debe pasar inadvertida / Atherogenic dyslipidemia: a condition that should not be overlooked

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The effects of treatment on lipoprotein subfractions evaluated by polyacrylamide gel electrophoresis in patients with autoimmune hypothyroidism and hyperthyroidism.

BACKGROUND: Atherogenic dyslipoproteinemia is one of the most important risk factor for atherosclerotic changes development. Hypothyroidism is one of the most common causes of secondary dyslipidemias which results from reduced LDL clearance and therefore raised levels of LDL and apoB. Association between small dense LDL (sdLDL) presentation and thyroid status has been examinated using polyacrylamide gel electrophoresis for lipoprotein subfractions evaluation. METHODS: 40 patients with diagnosed autoimmune hypothyroidism and 30 patients with autoimmune hyperthyroidism were treated with thyroxine replacement or thyreo-suppressive treatment. In both groups lipid profiles, LDL subractions, apolipoproteins (apoA1, apoB), apoA1/apoB ratio and atherogenic index of plazma (AIP) were examined before treatment and in state of euthyreosis. RESULTS: Thyroxine replacement therapy significantly reduced levels of total cholesterol (TC), LDL, triglycerides (TG) and also decreased levels of sdLDL (8,55±11,671 vs 0,83±1,693mg/dl; p<0,001), apoB and AIP. For estimation of atherogenic lipoprotein profile existence an AIP evaluation seems to be better than apoB measurement because of the more evident relationship with sdLDL (r=0,538; p<0,01). Thyreo-suppressive therapy significantly increased levels of TC, LDL, TG and apoB. The sdLDL was not found in hyperthyroid patients. CONCLUSIONS: Atherogenic lipoprotein profile was present in 52.5% of hypothyroid subjects, which is higher prevalence than in normal, age-related population. Substitution treatment leads to an improvement of the lipid levels, TG, apoB, AIP and LDL subclasses. It significantly changed the presentation of sdLDL - we noticed shift to large, less atherogenic LDL particles. Significantly positive correlation between sdLDL and TAG; sdLDL and VLDL alerts to hypertriglyceridemia as a major cardiovascular risk factor.

Evaluación durante 6 años de la dislipidemia en un centro de salud. Importancia de las acciones de mejora / A 6-year evaluation of dyslipidemia in a health center: Importance of improvement actions

Introducción. La dislipidemia, sobre todo el aumento del colesterol LDL, se ha demostrado como uno de los factores de riesgo más importantes en la génesis de la afectación coronaria. La prevalencia de las dislipidemias en España es alta. El objetivo del presente trabajo es valorar la evolución de los pacientes dislipidémicos de nuestro centro de salud durante 6 años y ver si se ha producido una mejora en el control de los mismos tras la presentación de la evaluación de los 3 primeros años y la actualización del protocolo de dislipidemias del centro de salud. Pacientes y método. Evaluación Periodo 1 (2006-2008): 267 pacientes dislipidémicos. Evaluación Periodo 2 (2009-2011): 222 pacientes, excluidos exitus y cambios de domicilio. Variables: edad, sexo, antecedentes personales de ECV, factores de riesgo vascular, lípidos, número de analíticas, tratamiento farmacológico, niveles de riesgo CV y porcentajes en objetivos de control. Resultados. Edad media 66,2 años (DE 13,4), mujeres 66,3%. Periodo 1-Periodo 2: colesterol total: 221,9-196,6 mg/dl (p = 0,000); colesterol LDL: 147,9-115,8 mg/dl (p = 0,000). En objetivos terapéuticos, pacientes riesgo alto: 14-50,5% (p = 0,024); riesgo medio: 35-68,1% (p = 0,038); riesgo bajo: 44-68,2% (p = NS). Tratamiento farmacológico 68-77% (p = 0,000). Modificación tratamiento: 30-43% (p = 0,001). Cumplimiento terapéutico: 75-86% (p = 0,003). Sin tratamiento riesgo alto: 15,4-16,3% (p = NS). Conclusiones. Se ha producido una mejoría significativa en el Periodo 2, sobre todo en los pacientes de riesgo alto, tras presentar los resultados de la evaluación del Periodo 1 y haber actualizado, en el centro de salud, el protocolo de dislipidemias. Hay pacientes con riesgo alto sin tratamiento hipolipidemiante que se deben detectar y revisar. (AU)

Introduction. Dyslipidemia, especially an increased LDL-cholesterol, has been shown to be one of the most important risk factors in the genesis of coronary involvement. The prevalence of dyslipidemias in Spain is high. The objective of this study is to assess the progress of dyslipidemic patients in our health center over a 6-year period, and see if there has been any improvement in its control after the presentation of the evaluation of the first 3 years, as well as an updated dyslipidemia protocol. Patients and methods. Assessment Period 1 (2006-2008): 267 patients with dyslipidemia. Assessment Period 2 (2009-2011): 222 patients, excluding exitus and address changes. Variables: age, sex, personal history of CVD, vascular risk factors, lipids, drug treatment, risk levels, and percentages of CV control objectives. Results. Mean age was 66.2 years (SD 13.4), 66.3% women. Period 1-Period 2: Total cholesterol: 221.9-196.6 mg/dl (P = .000); LDL-cholesterol: 147.9-115.8 mg/dl (P = .000). In high risk patients, therapeutic targets: 14-50.5% (P = .024); medium risk: 35-68.1% (P = .038); low risk: 44-68.2% (P = NS). Pharmacotherapy 68-77% (P = .000). Changing treatment: 30-43% (P = .001). Adherence: 75-86% (P = .003). Untreated high risk: 15.4-16.3% (P = NS). Conclusions. There was a significant improvement in Period 2, especially in high-risk patients, after presenting the results of the evaluation for Period 1 and with the updated dyslipidemia protocol. There are high risk patients without lipid-lowering treatment to be detected and reviewed (AU)

Genetic and biochemical analyses in dyslipidemic patients undergoing LDL apheresis.

OBJECTIVE: Familial hypercholesterolemia (FH) can be due to mutations in LDLR, PCSK9, and APOB. In phenotypically defined patients, a subset remains unresponsive to lipid-lowering therapies and requires low density-lipoprotein (LDL) apheresis treatment. In this pilot study, we examined the genotype/phenotype relationship in patients with dyslipidemia undergoing routine LDL apheresis. DESIGN: LDLR, APOB, and PCKS9 were analyzed for disease-causing mutations in seven patients undergoing routine LDL apheresis. Plasma and serum specimens were collected pre- and post-apheresis and analyzed for lipid concentrations, Lp(a) cholesterol, and lipoprotein particle concentrations (via NMR). RESULTS: We found that four patients harbored LDLR mutations and of these, three presented with xanthomas. While similar reductions in LDL-cholesterol (LDL-C), apolipoprotein B, and LDL particles (LDL-P) were observed following apheresis in all patients, lipid profile analysis revealed the LDLR mutation-positive cohort had a more pro-atherogenic profile (higher LDL-C, apolipoprotein B, LDL-P, and small LDL-P) pre-apheresis. CONCLUSION: Our data show that not all clinically diagnosed FH patients who require routine apheresis have genetically defined disease. In our small cohort, those with LDLR mutations had a more proatherogenic phenotype than those without identifiable mutations. This pilot cohort suggests that patients receiving the maximum lipid lowering therapy could be further stratified, based on genetic make-up, to optimize treatment.

Plaque regression and progenitor cell mobilization with intensive lipid elimination regimen (PREMIER) trial design.

Progression of lipid rich necrotic core elements of atherosclerotic vulnerable plaque (VP) or its rupture leads to a majority of cardiovascular events. Endothelial progenitor cells (EPC) contribute to vascular healing and play a crucial role in repair following ischemic injury primarily by endothelialization of VP and neovascularization of ischemic myocardium. We present the rationale and design of the Plaque Regression and Progenitor Cell Mobilization with Intensive Lipid Elimination Regimen or the PREMIER Trial, which is designed to address the question for the very first time whether a highly intensive low-density lipoprotein (LDL)-lowering therapy with LDL-apheresis could lead to a more rapid and detectable reduction in coronary atheroma volume, along with a robust mobilization of EPC compared to standard statin therapy, in patients selected for percutaneous coronary intervention for an acute coronary syndrome.

An international survey of pediatric apheresis practice.

INTRODUCTION: Pediatric apheresis (PA) has distinct characteristics compared to adult apheresis, and requires specialized knowledge and experience to perform safely, particularly in low-weight patients. As evidence-based medicine advances the field of therapeutic apheresis, increased attention must be paid to pediatric patients with conditions for which apheresis is indicated. METHODS: An electronic survey of >5,000 potential participants throughout the world was conducted to ascertain the scope and the current state of practice. RESULTS: The survey elicited 159 responses from 12 countries; 107 of the responses provided sufficient information for analysis. Participants performed an average of 176 PA procedures/year (range: 1-2,000). The types of PA procedures were therapeutic plasma exchange (92% of centers), red cell exchange (86%), leukocyte depletion (87%) and peripheral blood hematopoietic progenitor cell collection (72%). More than 65% of the centers had treated children older than 5 years with PA. Many centers had also performed PA on younger children; 40% have treated patients <12 months of age; 61% had treated patients 1-5 years old. 36% of centers reported that they would perform apheresis regardless of patient weight; 18% used a 5 kg threshold, 11% used 5-10 kg, and 17% used 10 kg as their weight threshold. CONCLUSION: This report is the largest single survey of centers performing PA. The results provide information about the scope and diversity of PA and identify areas where considerable variability in practice exists. Further exploration of these differences could establish best practices in PA through international research and collaboration.

A comparison of five lipid extraction solvent systems for lipidomic studies of human LDL.

Lipidome profile of fluids and tissues is a growing field as the role of lipids as signaling molecules is increasingly understood, relying on an effective and representative extraction of the lipids present. A number of solvent systems suitable for lipid extraction are commonly in use, though no comprehensive investigation of their effectiveness across multiple lipid classes has been carried out. To address this, human LDL from normolipidemic volunteers was used to evaluate five different solvent extraction protocols [Folch, Bligh and Dyer, acidified Bligh and Dyer, methanol (MeOH)-tert-butyl methyl ether (TBME), and hexane-isopropanol] and the extracted lipids were analyzed by LC-MS in a high-resolution instrument equipped with polarity switching. Overall, more than 350 different lipid species from 19 lipid subclasses were identified. Solvent composition had a small effect on the extraction of predominant lipid classes (triacylglycerides, cholesterol esters, and phosphatidylcholines). In contrast, extraction of less abundant lipids (phosphatidylinositols, lyso-lipids, ceramides, and cholesterol sulfates) was greatly influenced by the solvent system used. Overall, the Folch method was most effective for the extraction of a broad range of lipid classes in LDL, although the hexane-isopropanol method was best for apolar lipids and the MeOH-TBME method was suitable for lactosyl ceramides.

Measurement of LDL-C after treatment with the CETP inhibitor anacetrapib.

Estimation of low-density lipoprotein cholesterol (LDL-C) using the Friedewald (FR) formula is often inaccurate when triglycerides are elevated or VLDL particle composition is altered. We hypothesized that LDL-C estimation by the FR formula and other measurement methods might also be inaccurate in individuals treated with a cholesteryl ester transfer protein (CETP) inhibitor. An assay comparison study was conducted using pre and posttreatment serum samples from 280 of the 811 patients treated with the CETP inhibitor anacetrapib in the DEFINE study (determining the efficacy and tolerability of CETP inhibition with anacetrapib). After 24 weeks of treatment with anacetrapib, mean LDL-C values by FR formula, Roche direct method (RDM) and Genzyme direct method (GDM) deviated from that measured by the ß-quantification (BQ) reference method by -12.2 ± 7.5, -10.2 ± 6.6, -10.8 ± 8.8 mg/dl, respectively. After treatment with anacetrapib, the FR formula and detergent-based direct methods provided lower LDL-C values than those obtained by the BQ reference method. The bias by the FR formula appeared to be due to an overestimation of VLDL-C by the TG/5 component of the formula. Evaluation of the clinical significance of these findings awaits comprehensive lipid and cardiovascular outcome data from ongoing Phase III clinical studies of anacetrapib.

[LDL-apheresis in patients with familial autosomal recessive hypercholesterolemia]. / LDL aferesi nella Ipercolesterolemia Autosomica Recessiva (ARH).

LDL-apheresis reduces the cardiovascular risk in patients with familial hypercholesterolemia. The addition of statin therapy in patients with autosomal recessive hypercholesterolemia may change the lipid profile to a less atherogenic pattern.

Impact of LDL apheresis on atheroprotective reverse cholesterol transport pathway in familial hypercholesterolemia.

In familial hypercholesterolemia (FH), low HDL cholesterol (HDL-C) levels are associated with functional alterations of HDL particles that reduce their capacity to mediate the reverse cholesterol transport (RCT) pathway. The objective of this study was to evaluate the consequences of LDL apheresis on the efficacy of the RCT pathway in FH patients. LDL apheresis markedly reduced abnormal accelerated cholesteryl ester transfer protein (CETP)-mediated cholesteryl ester (CE) transfer from HDL to LDL, thus reducing their CE content. Equally, we observed a major decrease (-53%; P < 0.0001) in pre-ß1-HDL levels. The capacity of whole plasma to mediate free cholesterol efflux from human macrophages was reduced (-15%; P < 0.02) following LDL apheresis. Such reduction resulted from a marked decrease in the ABCA1-dependent efflux (-71%; P < 0.0001) in the scavenger receptor class B type I-dependent efflux (-21%; P < 0.0001) and in the ABCG1-dependent pathway (-15%; P < 0.04). However, HDL particles isolated from FH patients before and after LDL apheresis displayed a similar capacity to mediate cellular free cholesterol efflux or to deliver CE to hepatic cells. We demonstrate that rapid removal of circulating lipoprotein particles by LDL apheresis transitorily reduces RCT. However, LDL apheresis is without impact on the intrinsic ability of HDL particles to promote either cellular free cholesterol efflux from macrophages or to deliver CE to hepatic cells.

The effect of low-density lipoprotein apheresis on ocular microcirculation in patients with hypercholesterolaemia: a pilot study.

AIM: To investigate the effect of low-density lipoprotein (LDL) apheresis on ocular microcirculation in patients with hypercholesterolaemia. METHODS: Six patients with hypercholesterolaemia were included in this study. The diameter of retinal vessels was measured continuously with the retinal vessel analyser before and after LDL apheresis. After baseline assessment a monochromatic luminance flicker was applied to evoke retinal vasodilation. Flicker response was then analysed 50, 70 and 120 s after baseline measurement. In addition, cholesterol, high-density lipoprotein, LDL and triglyceride levels were obtained to find a possible correlation between changes in retinal vessel diameter and lipid metabolism before and after apheresis. RESULTS: The mean diameter of the arterioles at baseline was 107.6±2.1 µm and the mean diameter of the venules at baseline was 132.8±3.2 µm. The diameter of the arterioles after apheresis increased to 111.2±2.3 µm after 50 s, 113.2±2.6 µm after 70 s and 113.7±2.6 µm after 120 s, showing a trend to statistical significance at all time points (p=0.046, p=0.028 and p=0.028, respectively). The mean diameter of the venules after apheresis increased to 138.8±5.9 µm after 50 s, 139.8±6.3 µm after 70 s and 141.2±6.0 µm after 120 s, showing a trend to statistical significance at all time points (all p=0.028). CONCLUSIONS: Changes in retinal vascular diameter seem to be associated with the systemic effect of a single LDL apheresis. Vasodilatation of the arterioles and the venules improved after LDL apheresis, indicating an improvement of ocular perfusion in patients with hypercholesterolaemia.

[Effect of water on silica gel adsorption of blood plasma components].

In this work, the study of properties of silica gel as an adsorbent for plasmasorption has been performed. Investigations have been realized of the effect of silica gel preliminary treatment conditions and a period of plasma with silica gel contact on plasmasorption characteristics of human blood plasma components, such as protein, triglycerides, cholesterol (high-density and low-density one). The results obtained can be used for variation of silica gel adsorption properties, in situ at the adsorbent preparation process. For explanation of the experimental concentration and kinetic (temporal) characteristics of plasmasorption, the model of silica gel grains charging at the hydration was used.

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.