Intraindividual comparison of two extracorporeal LDL apheresis methods: lipidfiltration and HELP

Lipoprotein apheresis: an established therapeutic modality for homozygous familial hypercholesterolemia patients refractory to PCSK9 inhibitors: a case report and literature review

Homozygous familial hypercholesterolemia (HoFH), is a rare genetic disorder characterized by dual mutations in the low-density lipoprotein receptor (LDLR) gene, leading to dysfunctional or absent LDLRs, often accompanied by severe premature Atherosclerotic Cardiovascular Disease (ASCVD) and exhibiting refractoriness to aggressive pharmacological interventions. Double filtration plasmapheresis (DFPP), a form of lipoprotein apheresis (LA), has been effectively utilized as an adjunctive treatment modality to reduce serum LDL-C levels in refractory cases of HoFH. Here, we report a case of a 36-year-old female with HoFH who developed xanthomas on her limbs and waist at age 7. Despite maximum-tolerated doses of statins from age 32, combined with ezetimibe and evolocumab, her LDL-C levels remained critically elevated at 12-14 mmol/L. Her genetic testing confirmed a homozygous LDLR mutation. At 35 years old, she experienced exertional chest pain, and percutaneous coronary intervention revealed severe calcific left main stenosis, necessitating stent implantation. Subsequently, she initiated once every 1-2 months DFPP. Pre-DFPP, her LDL-C and total cholesterol (TC) levels were 13.82 ± 3.28 and 15.45 ± 0.78 mmol/L, respectively. Post-DFPP, her LDL-C and TC levels significantly decreased to 2.43 ± 0.33 mmol/L (81.76 ± 4.11% reduction) and 3.59 ± 0.41 mmol/L (76.76 ± 2.75% reduction), respectively. Lipoprotein (a) and triglycerides also decreased by 89.10 ± 1.39% and 42.29 ± 15.68%,respectively. Two years later, there was no progression of coronary artery disease, and her symptoms and xanthomas regressed significantly. Collectively, DFPP effectively reduces LDL-C levels in refractory cases of HoFH and contributes to delaying ASCVD progression, representing an efficacious adjunctive therapeutic modality.

[Lipoprotein apheresis : State of the art and case report of the longest HELP treatment worldwide]

Lipoprotein apheresis is an extracorporeal procedure for the treatment of patients with homozygous familial hypercholesterolemia, patients with severe treatment-resistant hypercholesterolemia and patients with lipoprotein(a) hypercholesterolemia, who show progressive atherosclerotic cardiovascular disease despite optimal treatment. This article reports on the historical developments of the procedures, the most frequently used methods for apheresis as well as the data situation on efficacy and tolerability. Randomized prospective studies on clinical outcomes are not available. Furthermore, the article reports on a patient with homozygous familial hypercholesterolemia and 34 years of treatment with heparin-induced extracorporeal low-density lipoprotein (LDL) precipitation (HELP) apheresis, the longest treatment of this kind worldwide. A second patient with combined heterozygous familial hypercholesterolemia and 31 years of liposorber and HELP apheresis is also described. The observational studies and the case reports demonstrate the safety and long-term tolerability of the procedure.

The effect of Womersley number and particle radius on the accumulation of lipoproteins in the human aorta

The purpose of this study is to compare the effects of the different physical factors on lipoproteins accumulation in the aorta artery. Results revealed that hemodynamic parameters (WSS, OSI, RRT) together affect spatial distributions of lipoproteins concentration in the human aorta. Moreover, decreasing the frequency of pulsatile flow and particle size leads to more lipoproteins accumulated on the luminal surface. In addition, given the same flow rate, the pulsatile flow could reduce lipoproteins concentration in the luminal surface of aorta relative to a steady flow condition. The present computer strategy may have great potential in predicting the local atherosclerosis lesion.

Multimodal lipid-lowering treatment in pediatric patients with homozygous familial hypercholesterolemia-target attainment requires further increase of intensity

BACKGROUND

Familial hypercholesterolemia (FH) causes premature cardiovascular disease (CVD). Lipoprotein apheresis (LA) is recommended as first-line lipid-lowering treatment (LLT) for homozygous (ho) FH.

METHODS

Efficacy of multimodal LLT including lifestyle counseling, drug treatment, and LA was analyzed in 17 pediatric hoFH or compound heterozygous (c-het) FH patients, who commenced chronic LA in Germany before the age of 18.

RESULTS

At time of diagnosis, mean low-density lipoprotein cholesterol (LDL-C) concentration was 19.6 mmol/l (756 mg/dl). Multimodal LLT resulted in 73% reduction of mean LDL-C concentration including a 62% contribution of LA. Only three children (18%) achieved mean LDL-C concentrations below the recommended pediatric target of 3.5 mmol/l (135 mg/dl). In 13 patients (76%) during chronic LA, neither cardiovascular events occurred nor was CVD progression detected clinically or by routine imaging techniques. In four patients (24%), cardiovascular events documented progression of CVD despite weekly LA, including one death due to coronary and cerebrovascular CVD which was not stabilized after commencing LA. Based on the mutational status, only 6 out of the 17 children were candidates for proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibition. Two already responded with further LDL-C decrease by 40%.

CONCLUSIONS

Next to drug therapy, regular LA is an essential component of LLT for approaching LDL-C targets in children with hoFH or c-hetFH, which was successful only in a minority of children. Progression of CVD morbidity and resulting mortality remain unresolved issues. Early and intensified multimodal LLT guided by risk factors beyond LDL-C concentration is needed to improve outcome.

Current Role of Lipoprotein Apheresis in the Treatment of High-Risk Patients

Lipoprotein apheresis (LA) is a therapeutic approach to save the lives of patients who are at an extremely high risk of developing cardiovascular events (CVE), especially after all other therapeutic options were not tolerated, or appeared not to be effective enough. Homozygous familial hypercholesterolemia represents a clear indication to start LA therapy. Another recognized indication is a severe hypercholesterolemia, which induced CVE, often in association with other risk factors. In the last years, an expressive elevation of lipoprotein(a) (Lp(a)) emerged as an indication for LA. In Germany, progress of atherosclerosis should have been documented before the permission to start LA therapy is given in these patients. Usually, all LA methods acutely decrease both LDL-C and Lp(a). However, specific columns which reduce only Lp(a) are available. Case reports and prospective observations comparing the situation before and during LA therapy clearly show a high efficiency with respect to the reduction of CVE, especially in patients with high Lp(a) levels. PCSK9 inhibitors may reduce the need for LA in patients with heterozygous or polygenetic hypercholesterolemia, but in some patients, a combination of these drugs with LA will be necessary. In the future, an antisense oligonucleotide against apolipoprotein(a) may offer an alternative therapeutic approach.

Whole Blood Selective LDL-Apheresis: A Comparison of Two Different Adsorbers

The effects of LDL-apheresis with whole blood adsorption were compared in five patients with severe familial and ARH hypercholesterolemia, using two different sorbents, polyacrylic acid with the DALI system and dextran sulfate with the DX21 system. The patients were treated bimonthly with both systems at random. For each patient, the same number of procedures with both systems was considered, ranging from 2 to 11 for each technique. During a period of observation of 26 months, a total of 80 LDL-apheresis, 40 with the DALI system and 40 with the DX21, with equivalent volumes of treated whole blood was evaluated (mean blood volume treated: 8151 mL). Total and LDL cholesterol were effectively lowered with both techniques. The mean percentage reduction of total cholesterol and LDL-cholesterol respectively was 54.1±7.7% and 62.3±9% with the DALI system, 52.7±7.8% and 59.2±9.5 with the DX21: t-test for paired data showed p: 0.01 for LDL-cholesterol. The reduced removal of LDL-C with dextran sulfate, either within the same patient or all the patients taken together was of a very limited amount compared to polyacrylic acid. The superiority of one over the other sorbent cannot be affirmed: further studies on a higher number of procedures and patients, together with an evaluation of biocompatibility effects, compared to polyacrylic acid may clarify and make evident a significant difference in efficacy between the two systems.

Efficacy of lipid reduction with DALI and MONET

BACKGROUND

Lipidapheresis techniques are increasingly used to treat drug-resistant hyperlipidemia but few efficacy studies under routine application are available. In this multicenter observational study we investigated direct adsorption of lipoproteins (DALI) and lipoprotein filtration (MONET) for the short and the long-term effects on lipid-lowering effects.

METHODS

Data of 122 apheresis patients from 11 centers (DALI: n = 78, MONET: n = 44) were prospectively collected for a period of 2 years. Routine lipid measurements were evaluated (2154 DALI and 1297 MONET sessions). It was investigated whether the relative reduction of LDL-C during apheresis session achieves at least 60%. Also relative reduction of total cholesterol, HDL, triglyceride, and Lp(a) were analyzed.

RESULTS

The relative reduction of LDL-C was at least 60%: DALI: 70.62%, 95% CI = [69.34; 71.90] and MONET: 64.12%, 95% CI = [60.79; 67.46]. Also triglycerides were reduced with both systems: DALI 38.63%, 95% CI = [33.95; 43.30] vs. MONET 57.68%, 95% CI = [51.91; 63.45]. Relative reductions of total cholesterol were in the range of 50% (DALI 95% CI = [46.49; 49.65] MONET 95% CI = [48.93; 55.26]) and of Lp(a) in the range of 65% (DALI 95% CI = [61.92; 65.83] MONET 95% CI = [63.71; 70.30]. HDL reduction was: DALI 15.01%, 95% CI = [13.22; 16.79] and MONET 22.59%, 95% CI = [19.33; 25.84]. For both devices treated patient plasma/blood volume and in case of DALI the use of the larger adsorber configurations (DALI 1000 and DALI 1250) were independent positive predictors of the relative reduction of LDL-C and of Lp(a).

CONCLUSIONS

Both systems effectively improved lipid profile and reduced atherogenic lipids. The results point to the importance of the individualized application of these valuable therapies to achieve clinical targets.

Use of plasma exchange or double filtration plasmapheresis to reduce body burden of polychlorinated biphenyls: A pilot trial

The aim of the study was to examine whether plasma exchange (PE) or selective double filtration plasmapheresis (DFPP) is able to reduce the internal Polychlorinated biphenyl (PCB) burden of highly exposed participants of the health effects in high-level exposure to PCB (HELPcB) cohort. HELPcB is a surveillance program for former PCB-exposed workers of a German capacitor recycling company. After comparative evaluation of PE and DFPP in a phase I, DFPP was chosen as method for further treatment. In phase II, five participants underwent DFPP at weekly intervals for the duration of 12 weeks. Six PCB species were selected as indicators and were analyzed in the plasma before and after each treatment and 4 weeks after the last treatment. The PCB levels before and after each DFPP treatment showed a significant reduction in PCB blood levels; however, there was no significant change in PCB levels within the samples collected before each treatment as compared with the samples collected in the following week before treatment. Even the difference between PCB levels at the onset of the study and 4 weeks after the last treatment was not significant. The results of this pilot trial do not encourage further investigations in using therapeutic apheresis to reduce the PCB body burden.

Lipoprotein Apheresis

Patients with familial hypercholesterolemia (FH) have early development of atherosclerosis and cardiovascular disease (CVD). Lipid level-lowering medications are not always successful in reducing increased low-density lipoprotein C (LDL-C) levels. Lipoprotein apheresis (LA) therapy has proven its clinical benefit in reducing CVD events for patients with FH with hypercholesterolemia. LA reduces LDL-C levels by more than 60% in patients with FH and reduces CVD events. LA also reduces Lp(a) levels and CVD events. LA reduces inflammatory markers and blood viscosity.

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.

Current view: indications for extracorporeal lipid apheresis treatment

Background

One of the first investigations concerning extracorporeal treatment of hypercholesterolemia was performed in 1967 by plasma exchange in patients with homozygous or severe heterozygous familial hypercholesterolemia (FH). In the following decades, several specific lipid apheresis systems were developed to efficiently eliminate low-density lipoprotein (LDL) cholesterol and Lp(a) cholesterol in hypercholesterolemic patients. In the early 1980s, the main clinical indication has been homozygous FH including mainly children and pregnant women. In consideration of the current development of lipid-lowering regimens and scientific knowledge of preventing progression of cardiovascular diseases, the spectrum of indications to initiate lipid apheresis was extended due to still insufficient lipid-lowering therapy in some clinical cases. However, a generally accepted indication for lipid apheresis treatment is still under discussion. In Germany, the target-oriented distribution of increasingly limited healthcare resources demand data which support the benefit of established treatment procedures such as lipid apheresis. In recent years, the Federal Joint Committee (G-BA), a paramount decision-making body of the German Healthcare System, issued to reassess the approval of chronic lipid apheresis therapy for regular reimbursement. Therefore, in 2005, an interdisciplinary German Apheresis Working Group has been established by members of both the German societies of nephrology. One of the first goals of this working group was a revision of the indications for lipid apheresis corresponding to current guidelines and recommendations for the treatment of lipid disorders. In addition, recently new pathophysiological perceptions of the impact of lipoproteins on atherogenesis and thrombosis were also considered.

Methods and Results

Since 2005, the working group met on a regular basis to substantiate the first defined goals. The indications for lipid apheresis were critically revised with respect to actual results from clinical investigations, cardiovascular guidelines, and scientific knowledge and were accepted by the members of the apheresis working group.

Conclusions

There is consensus between the medical societies and health insurance funds regarding the need for general accepted guidelines for lipid apheresis. Recommendations for the indications of lipid apheresis were developed, but additionally these results should be confirmed by medical societies to transform them to guidelines. However, due to limited data showing that lipid apheresis has effects on the progression of cardiovascular diseases all members of the apheresis working group support a project for creating a lipid apheresis registry. This apheresis registry has been developed and recently started. The primary goal is to substantiate prospective long-term data on clinical outcome of chronic lipid apheresis treatment and to support additional clinical research activities in this field. In addition, this registry should comply with the actual requests of the Federal Joint Committee (G-BA).

A child with night blindness: preventing serious symptoms of Refsum disease

Refsum disease is a genetic progressive neurological disorder caused by neurotoxic phytanic acid, a nutritional component patients are unable to metabolize. Symptoms include retinopathy, polyneuropathy, ataxia, and deafness. They are variable and rarely recognized before adulthood. The authors report the case of a 14-year-old girl diagnosed because of night blindness. They treated her with a phytanic acid-poor diet and extracorporeal lipid apheresis. They used different methods over a 30-month period. Thereafter, the patient was treated with diet only. Membrane filtration and heparin-induced extracorporeal low-density lipoprotein precipitation apheresis were well tolerated. Withdrawal of phytanic acid was studied quantitatively. During a 5-year period, blood phytanic acid levels decreased to a noncritical range. The patient remained free of ophthalmological and neurological progression for a total observation of 12 years. Early diagnosis and effective measures to keep the phytanic acid load low can probably prevent the serious sequelae of Refsum disease. Developing a method for newborn screening is desirable.

Different inflammatory responses induced by three LDL-lowering apheresis columns

Low-density lipoprotein (LDL) apheresis is well-established in selected patients with uncontrolled LDL levels. As such treatment affects biomarkers important in atherosclerosis and acute coronary syndromes, we systematically compared the inflammatory response induced by three LDL apheresis columns. Three patients with heterozygous familial hypercholesterolemia participated in a cross-over study with six consecutive treatments with three different LDL apheresis columns: DL-75 (whole blood adsorption), LA-15 (plasma adsorption), and EC-50W (plasma filtration). Biochemical parameters and inflammatory biomarkers, including complement activation products and 27 cytokines, chemokines, and growth factors were measured before and after treatment. Complement was activated through the alternative pathway. The final end product sC5b-9 increased significantly (P < 0.01) and equally with all devices, whereas the anaphylatoxins C3a and C5a were lower by use of the adsorption columns. Hs-CRP was reduced by 77% (DL-75), 72% (LA-15), and 43% (EC-50W). The cytokines were consistently either increased (IL-1ra, IP-10, MCP-1), decreased (IFN-gamma, TNF-alpha, RANTES, PDGF, VEGF), or hardly changed (including IL-6, IL8, MIP-1alphabeta) during treatment. The changes were in general less pronounced with the adsorption columns. All columns reduced LDL significantly and to the same extent. In conclusion, three LDL-apheresis devices with equal cholesterol-lowering effect differed significantly with respect to the inflammatory response.

Dextran-sulfate-adsorption of atherosclerotic lipoproteins from whole blood or separated plasma for lipid-apheresis—Comparison of performance characteristics with DALI and lipidfiltration

For many years dextran sulfate adsorption (DSA) treatment of separated plasma has been an established technology for low-density lipoprotein (LDL)-elimination. Recently a system for the treatment of whole blood based on DSA was introduced into clinical practice. To further characterize DSA treatment of whole blood, the performance characteristics of both DSA modalities were compared at two investigational sites with two alternative LDL apheresis systems being already in routine clinical use. In prospective cross-over design, DSA whole blood treatment was compared with a whole blood polyacrylate LDL adsorption system (DALI) in one study group. DSA for plasma treatment was compared with Lipidfiltration in cross-over design in a second study group. In total, 12 patients on chronic LDL apheresis received 169 treatments. Six patients were treated twice with whole blood polyacrylate adsorption and twice with whole blood DSA. LDL-cholesterol (74.9-78.0%) and lipoprotein (a) (72.1-73.3%) were reduced by both with equal efficacy. DSA achieved a significantly higher reduction rate of fibrinogen. Another six patients were treated eight times with DSA plasma adsorption followed by 16 Lipidfiltration treatments. LDL-cholesterol (67.0-70.2%) and lipoprotein (a) (69.2-73.7%) were reduced by both with equal efficacy. Fibrinogen was eliminated more efficiently by Lipidfiltration (50.2 vs. 38.5%). DSA proved to be a safe and effective in both treatment modes, for plasma as well as for whole blood. At the discretion of the apheresis specialist, depending upon the status of national approval, DSA of whole blood complements the armamentarium of powerful modalities for extracorporeal elimination of atherosclerotic lipoproteins to meet specific individual, medical, or logistic needs.

LDL-apheresis therapy

Low-density lipoprotein (LDL)-apheresis is an effective means for acutely lowering plasma cholesterol (LDL reduction > 60%) and reducing cardiovascular events in patients with uncontrolled hypercholesterolemia who are genetically predisposed or resistant to standard therapy. Despite its known benefit, apheresis is performed in only a minority of qualified patients. In addition to reducing plasma cholesterol, apheresis can alter other markers of vascular disease (inflammation, rheology, thrombosis, and fibrinolysis). The acute and chronic changes to the vascular system may warrant LDL-apheresis use in other diseases.

Plasma exchange in severe hypertriglyceridemia a clinical study

BACKGROUND

Hypercholesterolemia and hypertriglyceridemia are independent risk factors for atherosclerotic heart diseases. Moreover acute pancreatitis may occur in patients with severe hypertriglyceridemia.

AIM OF THE STUDY

To evaluate the effectiveness of plasma exchange (PE) in patients with severe hypertriglyceridemia.

METHODS

Seven patients with severe hypertriglyceridemia (a triglyceride level of more than 1000mg/dl) were treated with PE. After PE, lipid and hematological parameters and side effects were evaluated.

RESULTS

Triglyceride levels decreased below 1000mg/dl in all patients. The levels of triglyceride and very low-density lipoprotein cholesterol (p<0.05 for both), and total cholesterol (p<0.005) decreased significantly. PE was well-tolerated. Liver and renal functions, hematological parameters, except for an increase in white blood cell counts, did not change significantly.

CONCLUSION

PE may be used safely and effectively in severe hyperlipidemic patients at risk of acute coronary events and acute pancreatitis. Further extended studies may provide more detailed information.

Lipidfiltration--safe and effective methodology to perform lipid-apheresis

Familial hypercholesterolemia (FH) not adequately responding to diet and drug therapy represents an indication for extracorporeal lipid-apheresis, which has become an highly effective and approved therapy for those patients in several countries. Based on different methodology, five treatment options of lipid-apheresis exist and are in widespread practical use covered by regular reimbursement in Germany. All methods are safe and demonstrate equivalent efficacy of reducing LDL cholesterol with respect to the single apheresis session as well as during long-term treatment. Therefore German reimbursement guidelines leave the choice of the method to the discretion of the apheresis center. Related to properties of the used technology all methods exhibit characteristic patterns of additional plasma protein elimination, which do not impair, but in part may increase the therapeutic benefit of lipid-apheresis. Fibrinogen reduction has to be mentioned as an example. The Lipidfiltration system is based on plasmafiltration previously referred to as membrane differential filtration (MDF), synonymous with double filtration plasmapheresis (DFPP). The new term Lipidfiltration was the result of technological progress in the manufacturing process of the plasmafilter resulting in enhanced sieving characteristics and capacity. The Lipidfiltration system is completed by a specifically designed therapy machine with optimised performance characteristics.

From membrane differential filtration to lipidfiltration: technological progress in low-density lipoprotein apheresis

Extracorporeal low-density lipoprotein (LDL) apheresis is an established and highly effective therapy for patients with familial hypercholesterolemia (FH) not adequately responding to diet and drug therapy alone. Based on different methodology, five treatment options of LDL apheresis are available and in widespread practical use in Germany. All methods are safe and demonstrate equivalent efficacy of reducing LDL cholesterol with respect to the single apheresis session as well as during long-term treatment. Owing to methodological properties all methods also exhibit characteristics of additional plasma protein elimination, which do not impair, but in part, increase the beneficial therapeutic effect of LDL apheresis. Fibrinogen reduction has to be mentioned as an example. The lipidfiltration system is based on plasmafiltration previously named membrane differential filtration (MDF), synonymous with double filtration plasmapheresis (DFPP). The new term lipidfiltration was the result of technological progress leading to a significant improvement of the efficiency. The system consists of a novel lipid filter with enhanced sieving characteristics and capacity, and is completed by an enhanced therapy machine with an optimized heating unit.