Lipid and low-density-lipoprotein apheresis. Effects on plasma inflammatory profile and on cytokine pattern in patients with severe dyslipidemia

Comparison of double-filtration plasmapheresis (DFPP) versus heparin-mediated extracorporeal LDL-precipitation (HELP)-apheresis in early-onset preeclampsia

OBJECTIVES

Preeclampsia (PE) is a major cause of maternal and fetal mortality, and preterm birth. Previous studies indicate that lipid-apheresis may prolong pregnancy, namely heparin-mediated extracorporeal LDL-precipitation (HELP)- and dextran sulfate cellulose (DSC)-apheresis. We now report on double membrane plasmapheresis (DFPP) in early-onset preeclampsia (eoPE).

STUDY DESIGN

Open pilot study assessing the prolongation of pregnancy in PE by lipoprotein-apheresis (DRKS00004527). Two women with eoPE were treated by DFPP and compared to a historical cohort of 6 patients with eoPE treated by HELP-apheresis (NCT01967355).

MAIN OUTCOME MEASURES

Clinical outcome of mothers and babies and prolongation of pregnancies (time of admission to birth).

RESULTS

Patient 1 (33y; 22 + 5/7GW) received 4 DFPP. Delivery day 19; birthweight 270 g; weight at discharge 2134 g on day 132. Patient 2 (35y; 21 + 4/7GW) received 2 DFPP. Delivery day 19; birthweight 465 g; weight at discharge 2540 g on day 104. DFPP was well tolerated by both patients.

CONCLUSIONS

DFPP proved to be save and pregnancies remained stable as long as 19 days. Although babies were born very preterm both babies could finally be dismissed from hospital. No relevant clinical differences between DFPP and HELP-apheresis could be observed. Therefore, DFPP may extend the range of available apheresis techniques to prolong pregnancies in early-onset preeclampsia. However, further studies are necessary to gain more information. REGISTER: (DRKS00004527).

Research Progress in the Clinical Treatment of Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is an autosomal dominant inheritable disease with severe disorders of lipid metabolism. It is mainly marked by increasing levels of plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), xanthoma, corneal arch, and early-onset coronary heart disease (CHD). The prevalence of FH is high, and it is dangerous and clinically underdiagnosed. The clinical treatment for FH includes both pharmacological and non-pharmacological treatment, of which non-pharmacological treatment mainly includes therapeutic lifestyle change and dietary therapy, LDL apheresis, liver transplantation and gene therapy. In recent years, many novel drugs have been developed to treat FH more effectively. In addition, the continuous maturity of non-pharmacological treatment techniques has also brought more hope for the treatment of FH. This paper analyzes the pathogenic mechanism and the progress in clinical treatment of FH. Furthermore, it also summarizes the mechanism and structure-activity relationship of FH therapeutic drugs that have been marketed. In a word, this article provides a reference value for the research and development of FH therapeutic drugs.

Repeated lipoprotein apheresis and immune response: Effects on different immune cell populations

BACKGROUND

Atherosclerosis is considered a chronic inflammation of arterial vessels with the involvement of several immune cells causing severe cardiovascular diseases. Lipoprotein apheresis (LA) improves cardiovascular conditions of patients with severely disturbed lipid metabolism. In this context, little is known about the impact of LA on various immune cell populations, especially over time.

METHODS

Immune cells of 18 LA-naïve patients starting weekly LA treatment were analyzed before and after four apheresis cycles over the course of 24 weeks by flow cytometry.

RESULTS AND CONCLUSIONS

An acute lowering effect of LA on T cell and natural killer (NK) cell subpopulations expressing CD69 was observed. The non-classical and intermediate monocyte subsets as well as HLA-DR⁺ 6-sulfo LacNAc⁺ monocytes were significantly reduced during the apheresis procedure. We conclude that LA has the capacity to alter various immune cell subsets. However, LA has mainly short-term effects than long-term consequences on proportions of immune cells.

The Importance of Arterial Stiffness Assessment in Patients with Familial Hypercholesterolemia

Cardiovascular diseases are still the leading cause of mortality due to increased atherosclerosis worldwide. In the background of accelerated atherosclerosis, the most important risk factors include hypertension, age, male gender, hereditary predisposition, diabetes, obesity, smoking and lipid metabolism disorder. Arterial stiffness is a firmly established, independent predictor of cardiovascular risk. Patients with familial hypercholesterolemia are at very high cardiovascular risk. Non-invasive measurement of arterial stiffness is suitable for screening vascular dysfunction at subclinical stage in this severe inherited disorder. Some former studies found stiffer arteries in patients with familial hypercholesterolemia compared to healthy controls, while statin treatment has a beneficial effect on it. If conventional drug therapy fails in patients with severe familial hypercholesterolemia, PCSK9 inhibitor therapy should be administered; if these agents are not available, performing selective LDL apheresis could be considered. The impact of recent therapeutic approaches on vascular stiffness is not widely studied yet, even though the degree of accelerated athero and arteriosclerosis correlates with cardiovascular risk. The authors provide an overview of the diagnosis of familial hypercholesterolemia and the findings of studies on arterial dysfunction in patients with familial hypercholesterolemia, in addition to presenting the latest therapeutic options and their effects on arterial elasticity parameters.

Membranous nephropathy complicated by immune thrombocytopenia treated with low-density lipoprotein apheresis: a case report and literature review

Immune thrombocytopenia (ITP) may lead to membranous nephropathy (MN). Here, we report a case of MN complicated by ITP and validate the hypothesis that circulating antiplatelet antibodies cause MN using immunofluorescence analysis for immunoglobulin (Ig) G subclass and anti-phospholipase A2 receptor (PLA2R) antibodies. A 39-year-old Japanese man with ITP, who had been treated with prednisolone for 10 months, achieved a stable disease condition. However, 4 months after tapering the dose down to 10 mg prednisolone, he developed nephrotic syndrome, with a urinary protein-to-creatinine ratio (U-PCR) of 10.6 g/g Cr and was admitted to our hospital. His platelet count, at 89,000/μL, was lower than the normal range, indicating the recurrence of ITP. Renal biopsy revealed the thickening of the glomerular basement membrane with the deposition of IgG and complement component 3. Predominant deposition of IgG1 and negativity for anti-PLA2R staining indicated secondary MN; however, no typical conditions of secondary MN were evident. Although oral prednisolone and cyclosporine A were administered, he was refractory to treatment. A total of 12 sessions of low-density lipoprotein apheresis (LDL-A) decreased his U-PCR to < 3 g/g Cr. Seven months after discharge, his U-PCR further decreased to 0.54 g/g Cr and platelet count recovered to > 200,000/μL. Our literature review reveals that this condition is refractory to steroid therapy. LDL-A can be an effective treatment in drug-resistant MN complicated by ITP.

LDL Apheresis and Lp (a) Apheresis: A Clinician's Perspective

Purpose of Review

Lipoprotein apheresis is the most effective means of lipid-lowering therapy. However, it’s a semi-invasive, time consuming, and chronic therapy with variable adherence. There are still no specific guideline recommendations for the management of patients on lipid apheresis. The purpose of this review is to discuss the clinical indications and major drawbacks of lipid apheresis in the light of recent evidence.

Recent Findings

Lipoprotein apheresis should be initiated at early ages and performed frequently to receive the expected cardiovascular benefits. However, in clinical practice, most patients experience ineffective apheresis and fail to reach lipid targets. This real-world failure is due to several factors including late diagnosis, delayed referral, and improper frequency of procedures. All these denote that awareness is still low among physicians. Another important factor is the semi-invasive, time consuming nature of the apheresis, leading to high refusal and low adherence rates. Moreover, apheresis decreases quality of life and increases the risk of depression. Mental status is also deteriorated in patients with familial hypercholesterolemia on lipid apheresis. New effective lipid lowering agents are underway with promising cardiovascular results.

Summary

To overcome the drawbacks, a structured approach, including standardized protocols for lipoprotein apheresis with regular cardiovascular follow-up is warranted. New effective lipid lowering agents with documented cardiovascular benefit, should be integrated into the treatment algorithms of patients on lipoprotein apheresis.

Desialylation of platelet surface glycans enhances platelet adhesion to adsorbent polymers for lipoprotein apheresis

Background:

Lipoprotein apheresis is an important therapeutic option in homozygous familial hypercholesterolemia, progressive atherosclerosis, or when depletion of lipoprotein(a) is indicated. It is generally regarded as safe, but drops in platelet counts as well as sporadic episodes of thrombocytopenia have been reported. We assessed the influence of platelet desialylation, which may be induced by endogenous or pathogen-derived neuraminidases, on platelet adhesion to polyacrylate-based adsorbents for whole blood lipoprotein apheresis.

Methods:

Medical grade platelet concentrates were incubated with neuraminidase in vitro and were circulated over adsorbent columns downscaled from clinical application.

Results:

Cleavage of terminal sialic residues resulted in platelet activation with significantly elevated expression of platelet factor 4 (PF4) and in enhanced platelet adhesion to the adsorbent, accompanied by a pronounced drop in platelet counts in the column flow-through.

Conclusion:

Alterations in endogenous neuraminidase activity or exogenous (pathogen-derived) neuraminidase may trigger enhanced platelet adhesion in whole blood lipoprotein apheresis.

Lomitapide-a Microsomal Triglyceride Transfer Protein Inhibitor for Homozygous Familial Hypercholesterolemia

PURPOSE OF REVIEW

Homozygous familial hypercholesterolemia (HoFH) is a rare, genetic condition characterized by high levels of Low density lipoprotein cholesterol (LDL-C); overt, early-onset atherosclerotic cardiovascular disease (ASCVD); and premature cardiovascular events and mortality. Lomitapide is a first-in-class microsomal triglyceride transfer protein inhibitor for the treatment of HoFH. This review provides an update on data emerging from real-world studies of lomitapide following on from its pivotal phase 3 clinical trial in HoFH.

RECENT FINDINGS

Recent registry data have confirmed that HoFH is characterized by delayed diagnosis, with many patients not receiving effective therapy until they are approaching the age when major adverse cardiovascular events may occur. Data from case series of varying sizes, and from a 163-patient registry of HoFH patients receiving lomitapide, have demonstrated that lomitapide doses are lower and adverse events less severe than in the phase 3 study. Lomitapide enables many patients to reach European Atherosclerosis Society LDL-C targets. Some patients are able to reduce frequency of lipoprotein apheresis or, in some cases, stop the procedure altogether-unless there is significant elevation of lipoprotein (a). Modelling analyses based on historical and clinical trial data indicate that lomitapide has the potential to improve cardiovascular outcomes and survival in HoFH. Real-world clinical experience with lomitapide has shown the drug to be effective with manageable, less marked adverse events than in formal clinical studies. Event modelling data suggest a survival benefit with lomitapide in HoFH.

Apheresis as emerging treatment option in severe early onset preeclampsia

Based on an early suggestion by Winkler et al. 2003 and a subsequent successful study by Wang et al. 2006 using lipid apheresis (LA) in 9 patients with preeclampsia to prolong pregnancies, the use of apheresis as therapeutic option in severe early onset preeclampsia has received increasing attention. Further studies using different LA systems also prolonged pregnancy and have been published in the last few years. Albeit using different LA systems and relying on different working hypothesis, all studies demonstrated a promising stabilisation against the disease's progression. Overall time from hospitalisation to the need for mandatory delivery was longer for those patients receiving apheresis compared to historical or matched control patients not receiving apheresis. These data will be reviewed and different hypotheses about the beneficial mechanism of action of apheresis will be discussed. Since up to now there is no curative treatment for preeclampsia other than observation and delivery, future work shall be encouraged.

Changes in serum afamin and vitamin E levels after selective LDL apheresis

BACKGROUND

Afamin is a plasma vitamin E-binding glycoprotein partially associated with ApoA1-containing high-density lipoprotein (HDL) subfractions. In a previous study, the serum vitamin E decreased after low-density lipoprotein (LDL) apheresis, while vitamin E/cholesterol ratio increased. We aimed to study the effect of LDL apheresis on serum afamin level.

METHODS

The serum level of afamin and oxidized LDL were measured by enzyme-linked immunosorbent assay in six severe heterozygous FH patients before and after their first LDL apheresis treatments and in seven healthy controls. We also investigated the changes in total cholesterol, LDL-C, HDL-C, ApoB, ApoA1, HDL subfractions, and α- and γ-tocopherol levels during the treatment. HDL subfractions were detected by an electrophoretic method on polyacrylamide gel (Lipoprint). Serum α- and γ-tocopherol levels were detected by gas chromatography-mass spectrometry.

RESULTS

The first treatment sessions decreased serum afamin levels by an average of 9.4%. Total cholesterol, LDL-C, HDL-C and ApoA1 levels decreased by 52.6; 61.8; 10.5; and 14.1%, respectively. We found that α- and γ-tocopherol levels markedly decreased (by 34.1 and 32.9%, respectively), while α- tocopherol/cholesterol and γ-tocopherol/cholesterol ratios significantly increased (by 41.4 and 40.3%, respectively). Oxidized LDL levels significantly decreased. There was a shift toward the larger HDL subfractions.

CONCLUSION

LDL apheresis moderately decreases the circulating levels of afamin parallel to lowering HDL-C and ApoA1 levels. Tocopherol levels decreases markedly compared to afamin levels, however, beneficial changes in vitamin E/cholesterol ratios, oxidized LDL levels and HDL subfraction distribution were detected. These additional effects of LDL apheresis may result in further cardiovascular risk reduction in FH patients.

The impact of citrate concentration on adhesion of platelets and leukocytes to adsorbents in whole blood lipoprotein apheresis

Lipoprotein apheresis is applied to deplete low density lipoprotein and other apolipoprotein B containing lipoproteins in patients with severe familial hypercholesterolemia, hypertriglyceridemia associated pancreatitis, or lipoprotein (a)-hyperlipoproteinemia. Anticoagulation of the extracorporeal circuit may influence cellular activation, as evidenced by a reduction of inflammatory parameters during regional citrate anticoagulation with acid citrate dextrose A (ACD-A) commonly used in whole blood lipid apheresis. While the citrate concentration in the extracorporeal circuit has to ensure efficient anticoagulation, citrate infusion into the patient should be limited to avoid citrate overload. We assessed the influence of citrate concentration on cellular activation during in vitro circulation of whole blood containing 2.8 mM citrate (ACD-A 1:40), 5.6 mM citrate (ACD-A 1:20), or 13 mM citrate over polyacrylate-based adsorbents for lipoprotein apheresis. We found increased platelet adhesion for anticoagulation with 2.8 mM citrate as compared to 5.6 or 13 mM citrate, as shown by cell counting and confirmed by scanning electron microscopy of adsorbent beads as well as by elevated levels of platelet activation markers and of platelet-derived microvesicles. Leukocytes showed an equivalent adhesion pattern, while red blood cells remained unaffected at all citrate concentrations. Passage of blood over two consecutive columns resulted in enhanced platelet adhesion to the second column, presumably due to upstream preactivation. In conclusion, citrate influences activation and adhesion of platelets and leukocytes in a concentration-dependent manner, and ACD-A 1:20, equivalent to a citrate concentration of 5.6 mM in whole blood, ensures minimal cellular activation during passage of whole blood over polyacrylate-based adsorbents.

Impact of selective LDL apheresis on serum chemerin levels in patients with hypercholesterolemia

Background

Selective low-density lipoprotein (LDL) apheresis is commonly used to treat patients with familial hypercholesterolemia (FH). Chemerin is an adipokine with putative roles in the regulation of lipid metabolism.

Methods

In our pilot study, we measured serum chemerin levels by enzyme-linked immunosorbent assay in six severe heterozygous FH patients before and after their first LDL apheresis treatments using the technique of direct adsorption of lipoproteins (DALI).

Results

The first treatment sessions decreased serum chemerin levels by an average of 27.26 %. While following one patient, 12 months of regular LDL apheresis resulted in a permanent reduction in his serum chemerin level. Changes in the lipoprotein subfractions measured by gel electrophoresis (Lipoprint) correlated with the reduction of chemerin levels. Furthermore, we eluted and then measured chemerin bound to the DALI column.

Conclusion

We conclude that LDL apheresis decreases the circulating level of chemerin by binding the protein to the column and thus improves lipoprotein subfraction pattern.

Lipoprotein(a) apheresis

PURPOSE OF REVIEW

Currently, different methods for extracorporeal elimination of atherogenic apolipoprotein B100 containing lipoprotein particles are used in clinical practice. Most of them effectively remove both lipoprotein(a) [Lp(a)] and LDL. The aim of this review is to highlight research describing the clinical advantages of specific Lp(a) immunosorption compared with other lipoprotein apheresis systems.

RECENT FINDINGS

Data on the utility of lipoprotein apheresis in patients with elevated Lp(a) level are limited. However, several longitudinal studies demonstrated improvement in cardiovascular outcomes when both Lp(a) and LDL cholesterol levels were decreased with different apheresis systems. The main limitation of these trials is the absence of a control group. First developed in 1991, studies on apheresis with a specific immunosorbent to Lp(a) were small and noncontrolled before 2000s. The only prospective controlled clinical trial utilising Lp(a) apheresis (Clinicaltrials.gov NCT02133807), demonstrated regression of coronary and carotid atherosclerosis when Lp(a) was removed weekly for 18 months.

SUMMARY

Lipoprotein apheresis usually affects multiple lipoproteins, and there are minimal data regarding the effect of specific removal of Lp(a) alone. There is a need for randomized controlled trial with specific Lp(a) apheresis to investigate its effect on cardiovascular outcomes.

Effects of different lipoprotein apheresis methods on serum protein levels

BACKGROUND

A total plasma exchange was the first extracorporeal method to treat patients with severe hypercholesterolemia. But in the long run it has several disadvantages. The newer lipoprotein apheresis (LA) methods claim to be more selective with respect to the removal of atherogenic lipoproteins and thus are supposed to avoid an additional protein loss.

METHODS

We wanted to compare the effect of these methods on serum protein concentrations (total serum protein, albumin, proteins measured with electrophoresis, immunoglobulins, fibrinogen, transferrin, and ferritin) which were checked before and after a single LA session in 75 patients. All patients underwent active LA treatment using 6 different LA methods (HELP, TheraSorb(®) LDL, DALI, Lipidfiltration, Liposorber D, MONET). Post-apheresis concentrations were corrected for changes in hematocrit.

RESULTS

The slightest impact on total serum protein was observed with the whole-blood methods. Liposorber D showed the least reduction of albumin levels. All LA methods had a small effect on alpha1-globulins and beta-globulins, but alpha2-and gamma-globulins were reduced to a different extent. A major effect was seen on the immunoglobulins when filtration methods were applied. In the patients treated with MONET, both pre- and post-apheresis Immunoglobulin M concentrations were below the normal range. HELP and the filtration methods significantly reduced the fibrinogen concentrations. The filtration methods also decreased ferritin levels but the post-apheresis ferritin levels were still in the normal range.

CONCLUSION

All LA methods had an influence on protein concentrations. At present, these findings will not yield an individualized treatment approach for any selective LA method due to the lack of prospective comparative studies. At minimum, special attention should be paid to protein concentrations in patients suffering from protein deficit.

Relationship between Sustained Reductions in Plasma Lipid and Lipoprotein Concentrations with Apheresis and Plasma Levels and mRNA Expression of PTX3 and Plasma Levels of hsCRP in Patients with HyperLp(a)lipoproteinemia

The effect of lipoprotein apheresis (Direct Adsorption of Lipids, DALI) (LA) on plasma levels of pentraxin 3 (PTX3), an inflammatory marker that reflects coronary plaque vulnerability, and expression of PTX3 mRNA was evaluated in patients with hyperLp(a)lipoproteinemia and angiographically defined atherosclerosis/coronary artery disease. Eleven patients, aged 55 ± 9.3 years (mean ± SD), were enrolled in the study. PTX3 soluble protein levels in plasma were unchanged by 2 sessions of LA; however, a downregulation of mRNA expression for PTX3 was observed, starting with the first session of LA (p < 0.001). The observed reduction was progressively increased in the interval between the first and second LA sessions to achieve a maximum decrease by the end of the second session. A statistically significantly greater treatment-effect correlation was observed in patients undergoing weekly treatments, compared with those undergoing treatment every 15 days. A progressive reduction in plasma levels of C-reactive protein was also seen from the first session of LA, with a statistically significant linear correlation for treatment-effect in the change in plasma levels of this established inflammatory marker (R² = 0.99; p < 0.001). Our findings suggest that LA has anti-inflammatory and endothelium protective effects beyond its well-established efficacy in lowering apoB100-containing lipoproteins.

Release and cellular origin of extracellular vesicles during circulation of whole blood over adsorbent polymers for lipid apheresis

Whole blood lipid apheresis is clinically applied in patients with familial hypercholesterolemia to reduce low density lipoprotein and other apolipoprotein B 100 containing lipoproteins. Here, the hemocompatibility of two polyacrylate-coated polyacrylamide-based polymers for lipid apheresis by evaluating the adhesion of blood cells to the adsorbent polymers, their respective activation, as well as the release of microvesicles during circulation of whole blood over the polymers was studied. Characterization of the adsorbents by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy revealed differences with respect to their surface morphology and their surface chemical composition. Despite these differences, equivalent amounts of leukocytes and platelets adhered to both polymers during circulation of whole blood over the adsorbent columns. The release of phosphatidylserine-exposing microvesicles, in contrast, increased significantly with increasing surface roughness and with the amount of polyacrylate groups at the adsorbent surface. The majority of microvesicles generated during blood-material contact were platelet-derived, and their release was associated with enhanced thrombin generation. Microvesicles were present in free and in cell-bound form, and 75% of all monocytes, but only 0.2% and 2.3% of red blood cells and platelets, respectively, were associated with microvesicles, pointing to a role of monocytes in the clearance of released microvesicles. Taken together, microvesicles are sensitive indicators for biomaterial-induced activation of blood cells in apheresis. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 636-646, 2017.

Recent advances in the understanding and care of familial hypercholesterolaemia: significance of the biology and therapeutic regulation of proprotein convertase subtilisin/kexin type 9

Familial hypercholesterolaemia (FH) is an autosomal co-dominant disorder that markedly raises plasma low-density lipoprotein-cholesterol (LDL-C) concentration, causing premature atherosclerotic coronary artery disease (CAD). FH has recently come under intense focus and, although there is general consensus in recent international guidelines regarding diagnosis and treatment, there is debate about the value of genetic studies. Genetic testing can be cost-effective as part of cascade screening in dedicated centres, but the full mutation spectrum responsible for FH has not been established in many populations, and its use in primary care is not at present logistically feasible. Whether using genetic testing or not, cholesterol screening of family members of index patients with an abnormally raised LDL-C must be used to determine the need for early treatment to prevent the development of CAD. The metabolic defects in FH extend beyond LDL, and may affect triacylglycerol-rich and high-density lipoproteins, lipoprotein(a) and oxidative stress. Achievement of the recommended targets for LDL-C with current treatments is difficult, but this may be resolved by new drug therapies. Lipoprotein apheresis remains an effective treatment for severe FH and, although expensive, it costs less than the two recently introduced orphan drugs (lomitapide and mipomersen) for homozygous FH. Recent advances in understanding of the biology of proprotein convertase subtilisin/kexin type 9 (PCSK9) have further elucidated the regulation of lipoprotein metabolism and led to new drugs for effectively treating hypercholesterolaemia in FH and related conditions, as well as for treating many patients with statin intolerance. The mechanisms of action of PCSK9 inhibitors on lipoprotein metabolism and atherosclerosis, as well as their impact on cardiovascular outcomes and cost-effectiveness, remain to be established.

LDL-apheresis contributes to survival extension and renal function maintenance of severe diabetic nephropathy patients: a retrospective analysis

AIMS

Low-density lipoprotein (LDL)-apheresis removes various molecules including LDL/oxidized LDL and inflammatory cytokines and recovers clinical laboratory parameters. It is not yet known whether these advantages of LDL-apheresis improve the prognosis of patients with diabetic nephropathy accompanied by nephrotic syndrome.

METHODS

In this study, three groups of patients were retrospectively surveyed in a single center, and followed for approximately 3 years: an LDL-apheresis cohort (LDL-a; N = 20); a control cohort meeting the selection criterion of severe proteinuria ≥ 3g/24h (control-All; N = 55); and a subgroup of control-All with more severe proteinuria ≥ 5 g/24h (control-mSP; N = 10), and evaluated the outcomes as survival and renal dysfunction and death/renal dysfunction free rate.

RESULTS

Death/renal dysfunction free rate was significantly higher in LDL-a than control-All (χ(2) = 4.50; P = 0.03) and control-mSP (χ(2) = 27.68; P < 0.001).

CONCLUSION

These results suggest the possibilities which LDL-apheresis is considered to contribute to survival extension and renal function maintenance of severe diabetic nephropathy patients.

Homozygous familial hypercholesterolaemia: new insights and guidance for clinicians to improve detection and clinical management. A position paper from the Consensus Panel on Familial Hypercholesterolaemia of the European Atherosclerosis Society

AIMS

Homozygous familial hypercholesterolaemia (HoFH) is a rare life-threatening condition characterized by markedly elevated circulating levels of low-density lipoprotein cholesterol (LDL-C) and accelerated, premature atherosclerotic cardiovascular disease (ACVD). Given recent insights into the heterogeneity of genetic defects and clinical phenotype of HoFH, and the availability of new therapeutic options, this Consensus Panel on Familial Hypercholesterolaemia of the European Atherosclerosis Society (EAS) critically reviewed available data with the aim of providing clinical guidance for the recognition and management of HoFH.

METHODS AND RESULTS

Early diagnosis of HoFH and prompt initiation of diet and lipid-lowering therapy are critical. Genetic testing may provide a definitive diagnosis, but if unavailable, markedly elevated LDL-C levels together with cutaneous or tendon xanthomas before 10 years, or untreated elevated LDL-C levels consistent with heterozygous FH in both parents, are suggestive of HoFH. We recommend that patients with suspected HoFH are promptly referred to specialist centres for a comprehensive ACVD evaluation and clinical management. Lifestyle intervention and maximal statin therapy are the mainstays of treatment, ideally started in the first year of life or at an initial diagnosis, often with ezetimibe and other lipid-modifying therapy. As patients rarely achieve LDL-C targets, adjunctive lipoprotein apheresis is recommended where available, preferably started by age 5 and no later than 8 years. The number of therapeutic approaches has increased following approval of lomitapide and mipomersen for HoFH. Given the severity of ACVD, we recommend regular follow-up, including Doppler echocardiographic evaluation of the heart and aorta annually, stress testing and, if available, computed tomography coronary angiography every 5 years, or less if deemed necessary.

CONCLUSION

This EAS Consensus Panel highlights the need for early identification of HoFH patients, prompt referral to specialized centres, and early initiation of appropriate treatment. These recommendations offer guidance for a wide spectrum of clinicians who are often the first to identify patients with suspected HoFH.

Lipoprotein apheresis and new therapies for severe familial hypercholesterolemia in adults and children

Familial hypercholesterolemia (FH), the most common and severe monogenic form of hypercholesterolemia, is an autosomal co-dominant disease characterized by an increased plasma low density lipoprotein (LDL)-cholesterol concentration and premature coronary heart disease (CHD). The clinical phenotype depends on the gene involved and severity of mutation (or mutations) present. Patients with homozygous or compound heterozygous FH have severe hypercholesterolemia (LDL-cholesterol >13 mmol/L) due to a gene dosing effect and without treatment have accelerated atherosclerotic CHD from birth, and frequently die of CHD before age 30. Cholesterol-lowering therapies have been shown to reduce both mortality and major adverse cardiovascular events in individuals with FH. Lipoprotein apheresis concomitant with lipid-lowering therapy is the treatment of choice for homozygous FH. This article describes the rationale and role of lipoprotein apheresis in the treatment of severe FH and outlines the recent advances in new pharmacotherapies for this condition.

Thrombocyte adhesion and release of extracellular microvesicles correlate with surface morphology of adsorbent polymers for lipid apheresis

Whole blood lipid apheresis is clinically applied to reduce low density lipoprotein cholesterol in patients with homozygous familial hypercholesterolemia. Here, we studied the correlation between physicochemical parameters, in particular, surface roughness and blood compatibility, of two polyacrylate-based and a dextran sulfate-based polymer for lipid apheresis. The adsorbent surface roughness was assessed by atomic force microscopy. Freshly isolated human thrombocytes were circulated over adsorbent columns downscaled equivalent to clinical use to study thrombocyte adhesion and microvesicle generation. Quantification of thrombocytes and microvesicles in the flow-through of the columns revealed that both thrombocyte adhesion and microvesicle generation increased with increasing adsorbent surface roughness. Activation of thrombocytes with thrombin receptor-activating peptide-6 favored their adhesion to the adsorbents, as demonstrated by preferential depletion of CD62(+) and PAC-1(+) thrombocytes. Taken together, enhanced polymer surface roughness fostered cell adhesion and microvesicle release, underscoring the role of extracellular microvesicles as markers of cellular activation and of blood compatibility.

Loss of plasma proprotein convertase subtilisin/kexin 9 (PCSK9) after lipoprotein apheresis

RATIONALE

Lipoprotein apheresis (LA) reduces low-density lipoprotein (LDL) levels in patients with severe familial hypercholesterolemia (FH). We have recently reported that >30% of plasma proprotein convertase subtilisin/kexin 9 (PCSK9) is bound to LDL, thus we predicted that LA would also reduce plasma PCSK9 levels by removing LDL.

OBJECTIVE

Pre- and post-apheresis plasma from 6 patients with familial hypercholesterolemia on 3 consecutive treatment cycles was used to determine changes in PCSK9 levels.

METHODS AND RESULTS

LA drastically reduced plasma LDL (by 77 ± 4%). Concomitantly, PCSK9 levels fell by 52 ± 5%, strongly correlating with the LDL drop (P=0.0322; r(2)=0.26), but not with decreases in triglyceride (49 ± 13%) or high-density lipoprotein levels (18 ± 2%). Levels of albumin, creatinine, and CK-MB did not show significant changes after LA. Similar to LDL, PCSK9 levels returned to pretreatment values between cycles (2-week intervals). Fractionation of pre- and post-apheresis plasma showed that 81 ± 11% of LDL-bound PCSK9 and 48 ± 14% of apolipoprotein B-free PCSK9 were removed. Separation of whole plasma, purified LDL, or the apolipoprotein B-free fraction through a scaled-down, experimental dextran sulfate cellulose beads column produced similar results.

CONCLUSIONS

Our results show, for the first time, that modulation of LDL levels by LA directly affects plasma PCSK9 levels, and suggest that PCSK9 reduction is an additional benefit of LA. Because the loss of PCSK9 could contribute to the LDL-lowering effect of LA, then (1) anti-PCSK9 therapies may reduce frequency of LA in patients currently approved for therapy, and (2) LA and anti-PCSK9 therapies may be used synergistically to reduce treatment burden.

Apheresis-inducible cytokine pattern change in children with homozygous familial hypercholesterolemia

Familial hypercholesterolemia is a genetic disorder that leads to severe atherosclerosis related cardiovascular complications in young adults. Extracorporeal elimination is a method of LDL-lowering procedures effective in patients with homozygous or severe heterozygous FH utilized in cases. The recruitment of leucocytes into the arterial intima is dependent on a cascade of events mediated through a diverse family of adhesion molecules. Several pro-inflammatory adhesion molecules are cleared by various lipid apheresis methods. This study showed that, LDL-apheresis led to several changes in circulating inflammatory factors which induced antiinflammatory and antiatherogenic changes in the plasma profile in homozygous familial hypercholesterolemic patients.