Protein adsorption during LDL-apheresis: proteomic analysis

Heparin-Mediated Extracorporeal Low-Density Lipoprotein Precipitation Apheresis for Treating Peripheral Arterial Disease in Patients with Chronic Kidney Disease

Patients with chronic kidney disease (CKD), particularly those with end-stage renal disease (ESRD), have a high prevalence of cardiovascular disease and peripheral arterial disease (PAD). Medical treatment is mainly based on risk factor management, and the surgical approach remains the gold standard treatment in specific conditions. Heparin-mediated extracorporeal low-density lipoprotein precipitation (H.E.L.P.) apheresis is effective in reducing circulating lipoprotein, fibrinogen, inflammatory mediators and procoagulant factors, thereby reducing cardiovascular risk in patients with familial hypercholesterolemia and hypertriglyceridemia. These activities may be effective in reducing symptoms and ischemic vascular lesions even in patients with severe PAD. We reported the application of a treatment protocol with H.E.L.P. apheresis in an ESRD patient with severe PAD without clinical improvement after severe revascularization who was not suitable for further surgical approaches, despite normal LDL cholesterol and lipoprotein (a). The H.E.L.P. protocol was characterized by an intensive first phase with weekly treatments followed by a single session every 10-15 days for 6 months of treatment. The overall clinical condition, foot lesions and walking distance improved significantly after the first 2 months of treatment, and foot amputation was avoided. Here, we review the main pathogenetic mechanisms through which LDL apheresis improves microcirculation and clinical outcomes. Its wider application may represent an optimal therapeutic option for patients unresponsive to standard treatment.

Beyond cholesterol-pleiotropic effects of lipoprotein apheresis

Cardiovascular disease is a leading cause of mortality worldwide, which is caused mainly by atherosclerosis, a chronic inflammatory disease of blood vessels. Therefore, atherosclerosis represents a complex disorder, which induces damage or imbalance on different levels: for example, genes, cytokines, lipoproteins, cells, vessels, and organs. Lipoprotein apheresis (LA) is a well-established extracorporeal treatment of severe hyperlipoproteinemia. In addition, LA may have simultaneously crucial effects on many other atherogenic factors during the treatments, for example, as vascular inflammation, rheology, mobilization of adult stem cells and gene expressions in blood or endothelial cells, which will be discussed in this short review. In addition, stable microRNAs besides tissues also appear in extracellular compartments, for example, vessels, involved in atherosclerotic processes, were found to be reduced by LA treatments. In summary, LA represents a complex therapeutic procedure, that provides an ideal tool for the treatment of complex disorders such as atherosclerosis.

Heparin-induced lipoprotein precipitation apheresis in dyslipidemic patients: A multiparametric assessment

Low-density lipoprotein (LDL) apheresis (LA) selectively eliminates lipoproteins containing apolipoprotein B 100 (ApoB100) on patients affected by severe dyslipidemia. In addition to lowering lipids, LA is thought to exert pleiotropic effects altering a number of other compounds associated with atherosclerosis, such as pro- and anti-inflammatory cytokines or pro-thrombotic factors. More knowledge needs to be gathered on the effects of LA, and particularly on its ability to modify blood components other than lipids. We performed a multiparametric assessment of the inflammatory, metabolic and proteomic profile changes after Heparin-induced lipoprotein precipitation (H.E.L.P.) apheresis on serum samples from nine dyslipidemic patients evaluating cholesterol and lipoproteins, plasma viscosity and density, metabolites, cytokines, PCSK9 levels and other proteins selectively removed after the treatment. Our results show that H.E.L.P. apheresis is effective in lowering lipoprotein and PCSK9 levels. Although not significantly, complement and inflammation-related proteins are also affected, indicating a possible transient epiphenomenon induced by the extracorporeal procedure.

Lipoprotein apheresis - Shortening of treatment intervals reduces cardiovascular events: Case reports

BACKGROUND

Lipoprotein (Lp-) apheresis is a life-long therapy, usually performed in weekly intervals. In some cases, however, atherosclerotic disease progresses despite adequate therapy with weekly Lp-apheresis and maximal lipid lowering medication. In an attempt to improve the effectiveness of therapy, we temporarily shortened treatment intervals of Lp-apheresis in patients with elevated lipoprotein(a) (Lp(a)) and further progression of coronary atherosclerosis despite weekly Lp-apheresis and maximal lipid lowering medication.

METHODS

We illustrate three case reports of patients with elevated Lp(a), who underwent regular weekly Lp-apheresis treatment for secondary prevention. The intensified treatment protocol contained three therapies in two weeks (alternating 2 per week and 1 per week).

RESULTS

The shortening of treatment intervals achieved a stabilization of atherosclerotic disease in case 1. After a total of 68 therapies in 52 weeks (1.31 sessions/week) the elective coronary angiography revealed excellent long-term results. In case 2, the intensified treatment protocol is still ongoing. The patient reported a decrease in angina pectoris and an increase in exercise capacity since the beginning of more frequent therapy sessions. In some cases, as it is shown in case 3, a fast decision for shortening the treatment intervals is necessary.

CONCLUSIONS

The intensified treatment regimen resulted in an improvement in clinical symptoms and no further progression of atherosclerosis. In conclusion, shorter therapeutic Lp-apheresis intervals, at least temporarily, should be considered in patients who suffer from clinical and/or angiographic progression of atherosclerosis, despite maximal lipid lowering medication and weekly Lp-apheresis.

From lipoprotein apheresis to proprotein convertase subtilisin/kexin type 9 inhibitors: Impact on low-density lipoprotein cholesterol and C-reactive protein levels in cardiovascular disease patients

In this observational study, we compared the effect of lipoprotein apheresis and evolocumab or alirocumab on levels of lipoprotein cholesterol, triglycerides and inflammatory markers (C reactive protein and interleukin 6) in cardiovascular patients ( n = 9). Patients were monitored during the last year of lipoprotein apheresis followed by six months of treatment with proprotein convertase subtilisin/kexin type 9 inhibitors. The biochemical parameters were determined pre- and post- every apheresis procedure for 12 months and then after one, three and six months of treatment with evolocumab (140 mg every two weeks [Q2W]) or alirocumab (75 mg or 150 mg every two weeks [Q2W]). Lipoprotein apheresis significantly reduced low-density lipoprotein cholesterol levels from 138 ± 32 mg/dl to 46 ± 16 mg/dl ( p < 0.001), with an inter-apheresis level of 114 ± 26 mg/dl. Lipoprotein(a) was also reduced from a median of 42 mg/dl to 17 mg/dl ( p < 0.01). Upon anti-proprotein convertase subtilisin/kexin type 9 therapy, low-density lipoprotein cholesterol levels were similar to post-apheresis (59 ± 25, 41 ± 22 and 42 ± 21mg/dl at one, three and six months, respectively) as well as those of lipoprotein(a) (18 mg/dl). However, an opposite effect was observed on high-density lipoprotein cholesterol levels: –16.0% from pre- to post-apheresis and +34.0% between pre-apheresis and proprotein convertase subtilisin/kexin type 9 inhibitors. Apheresis significantly reduced high-sensitivity C-reactive protein levels (1.5 ± 1.2 mg/l pre-apheresis to 0.6 ± 0.6 mg/l post-apheresis), while no changes were found upon proprotein convertase subtilisin/kexin type 9 mAbs administration. In conclusion, our study demonstrated that, by switching from lipoprotein apheresis to anti-proprotein convertase subtilisin/kexin type 9 therapies, patients reached similar low-density lipoprotein cholesterol and lipoprotein(a) levels, increased those of high-density lipoprotein cholesterol, and showed no changes on high-sensitivity C-reactive protein.

Dysregulation of the CD4+ T cells lineage differentiation in dyslipidemic patients and impact of lipoprotein-apheresis treatment: A case study

BACKGROUND AND AIM

Lipoprotein-apheresis (LA) is a therapeutic approach used against severe forms of dyslipidemia in patients who are non-responders or intolerant to pharmacological treatments. However, little is known about the potential pleiotropic effects of LA, particularly regarding the immune system and its regulation. Thus, in an attempt to analyse the potential effects of dyslipidemia and LA on the regulation of CD4+ T cells activation and lineage differentiation, we compared the CD4+ T cells cytokines secretion profiles of dyslipidemic patients before and after LA with the profiles observed in healthy donors.

METHODS

CD4+ T cells were isolated from 5 LA patients and 5 healthy donors and activated with anti-CD3 or anti-CD3 + anti-CD46 antibodies. The supernatants were collected after 36 h incubation and levels of secreted cytokines analysed by flow cytometry.

RESULTS

Our results revealed a deep remodelling of CD4+ T cells cytokines secretion patterns in dyslipidemic patients compared to healthy donors, as reflected by a 15 times higher IFN-γ secretion rate after CD3 + CD46 co-activation in dyslipidemic patients after LA compared to healthy subjects and 8 times higher after CD3 activation alone (p = 0.0187 and p = 0.0118 respectively). Moreover, we demonstrated that LA itself also modifies the phenotype and activation pattern of CD4+ T-cells in dyslipidemic patients.

CONCLUSION

These observations could be of fundamental importance in the improvement of LA columns/systems engineering and in developing new therapeutic approaches regarding dyslipidemia and associated pathologies such as atherosclerosis and type 2 diabetes.

Management of cardiovascular risk factors in patients with ANCA-associated vasculitis

OBJECTIVES

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is accompanied by increased cardiovascular (CV) risk. Treatment of AAV patients includes the management of conventional CV risk factors, primarily hypertension and hypercholesterolemia, while lipoprotein(a) (LP(a)) is an emerging potential target.

METHODS

We performed a multicenter, retrospective study in Germany. Patients were considered if they were between 18 and 90 years old and presented with AAV. Patients with arterial hypertension but no autoimmune disease were used as a control group (HTN reference group).

RESULTS

Compared to the reference group (n = 52), CV disease burden was significantly greater in patients with AAV (n = 53). Hypercholesterolemia was also more common in the AAV patients (71.7% vs 46.2% for the HTN; P = .008). Lipoprotein(a) levels were elevated in both groups, with 11.3% and 17.3% of the AAV and HTN groups, respectively, displaying a level above 0.6 g/l (P = .083). Guideline-recommended targets for low-density lipoprotein cholesterol and blood pressure levels were rarely met. According to Kidney Disease: Improving Global Outcomes guidelines, 72.5% of the patients with AAV should have been taking statins and/or ezetimibe for treatment of hyperlipidemia; however, only 24.3% of them were receiving such treatment. Blood pressure below ≤140/90 mmHg was reached in 78.6% of the patients with chronic kidney disease. However, for patients with chronic kidney disease and an albumin excretion rate of >30 mg/day, the recommended blood pressure is ≤130/80 mmHg, a value that was not reached in 65% of the AAV patients.

CONCLUSION

Patients with AAV are at high CV risk, but management of the associated risk factors is poor. In addition to improving the treatment of hypercholesterolemia and hypertension, lipoprotein(a) is a further potential target for reducing CV risk in individuals with AAV.

Long-term follow-up of circulating oxidative stress markers in patients undergoing lipoprotein apheresis by Direct Adsorption of Lipids (DALI)

OBJECTIVE

Beyond its well-established efficacy in lowering atherogenic lipids and lipoproteins, DALI (Direct Adsorption of Lipids) apheresis has been shown to have acute anti-inflammatory and endothelium-protective effects. In the present study, we investigated long-term effects of DALI procedures on circulating oxidative stress markers.

METHODS

Thirteen patients involved in the study underwent regular DALI apheresis for nearly two years. At sessions 1, 40 and 80 conventional lipid status and changes of systemic oxidative stress markers (oxidized LDL, anti-oxidized LDL antibodies, advanced oxidation protein products (AOPP), and myeloperoxidase (MPO)) were examined.

RESULTS

DALI procedure efficiently reduced atherogenic lipids/lipoproteins. On day three after apheresis lipid parameters returned to pre-apheresis values. They showed no tendency to increase or to decrease over time. No significant differences were found between 1st, 40th and 80th sessions. In a similar way, levels of oxidative stress biomarkers acutely decreased after apheresis sessions and rebounded on day three after apheresis. No significant differences were observed between sessions 1, 40, and 80.

CONCLUSION

DALI apheresis repeatedly decreases atherogenic lipid/lipoprotein profile and oxidative stress biomarker levels during each session. Among all investigated parameters no longitudinal effects over two years could be observed.

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.

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.

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.

Interactions of Apolipoproteins AI, AII, B and HDL, LDL, VLDL with Polyurethane and Polyurethane-PEO Surfaces

The lipoproteins (HDL, LDL, VLDL) are important components of blood present in high concentration. Surprisingly, their role in blood-biomaterial interactions has been largely ignored. In previous work apolipoprotein AI (the main protein component of HDL) was identified as a major constituent of protein layers adsorbed from plasma to biomaterials having a wide range of surface properties, and quantitative data on the adsorption of apo AI to a biomedical grade polyurethane were reported. In the present communication quantitative data on the adsorption of apo AI, apo AII and apoB (the latter being a constituent of LDL and VLDL), as well as the lipoprotein particles themselves (HDL, LDL, VLDL), to a biomedical segmented polyurethane (PU) with and without an additive containing poly(ethylene oxide) (material referred to as PEO) are reported. Using radiolabeled apo AI, apo AII, and apoB, adsorption levels on PU from buffer at a protein concentration of 50 μg/mL were found to be 0.34, 0.40, and 0.14 μg/cm(2) (12, 23, and 0.25 nmol/cm(2)) respectively. Adsorption to the PEO surface was <0.02 μg/cm(2) for all three apolipoproteins demonstrating the strong protein resistance of this material. In contrast to the apolipoproteins, significant amounts of the lipoproteins were found to adsorb to the PEO as well as to the PU surface. X-ray photoelectron spectra, following exposure of the surfaces to the lipoproteins, showed a strong phosphorus signal, confirming that adsorption had occurred. It therefore appears that a PEO-containing surface that is resistant to apolipoproteins may be less resistant to the corresponding lipoproteins.

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.

Proteomic analysis of proteins eliminated by low-density lipoprotein apheresis

Low-density lipoprotein apheresis (LDL-A) treatment has been shown to decrease serum LDL cholesterol levels and prevent cardiovascular events in homozygous patients with familial hypercholesterolemia. Recently, LDL-A treatment has been suggested to have beneficial effects beyond the removal of LDL particles. In this study, to clarify the preventive effects of LDL-A treatment on atherosclerosis, the waste fluid from the adsorption columns was analyzed. The waste fluid of LDL adsorption columns was analyzed by two-dimensional electrophoresis followed by mass spectrometry. Serum concentrations of the newly identified proteins before and after LDL-A treatment were measured by enzyme-linked immunosorbent assay. We identified 48 kinds of proteins in the waste fluid of LDL adsorption columns, including coagulation factors, thrombogenic factors, complement factors, inflammatory factors and adhesion molecules. In addition to the proteins that were reported to be removed by LDL-A treatment, we newly identified several proteins that have some significant roles in the development of atherosclerosis, including vitronectin and apolipoprotein C-III (Apo C-III). The serum levels of vitronectin and Apo C-III decreased by 82.4% and 54.8%, respectively, after a single LDL-A treatment. While Apo C-III was removed with very low-density lipoprotein (VLDL) and LDL, vitronectin was removed without association with lipoproteins. The removal of proteins observed in the waste fluid has a certain impact on their serum levels, and this may be related to the efficacy of LDL-A treatment. Proteomic analysis of the waste fluid of LDL adsorption columns may provide a rational means of assessing the effects of LDL-A treatment.

Acute and chronic effects of therapeutic apheresis

In most patients only a few sessions of apheresis treatment are necessary to see the benefit. This is the case of immunological diseases when the production of a pathologic component is limited in time or in microcirculation disturbances when changes of vascular function may occur. In the first instance the acute effect is likely due to the removal of the corresponding antibody, while in the second case the improvement of the endothelium-dependent vasodilation and the reduction of blood viscosity play a major role. In long-term treatment, as in the case of patients affected by familial hypercholesterolemia, the chronic effects of apheresis may lead to the repair of morphological alterations in the vascular wall. We report the recovery from ulcers in two hemodialysis patients suffering from peripheral arterial disease as the result of twenty-two sessions of rheopheresis. The reasons that justify these chronic actions may involve pleiotropic effects that are different according to the apheresis technique used.

Immunoadsorption therapy in patients with multiple sclerosis with steroid-refractory optical neuritis

BACKGROUND

In multiple sclerosis relapses refractory to intravenous corticosteroid therapy, plasma exchange is recommended. Immunoadsorption (IA) is regarded as an alternative therapy, but its efficacy and putative mechanism of action still needs to be established.

METHODS

We prospectively treated 11 patients with multiple sclerosis who had optical neuritis and fulfilled the indications for apheresis therapy (Trial registration DE/CA25/00007080-00). In total, five IA treatments were performed using tryptophan-IA. Clinical activity (visual acuity, Expanded Disability Status Scale, Incapacity Status Scale), laboratory values and visual evoked potentials were measured before, during and after IA, with a follow-up of six months. Moreover, proteomic analyses were performed to analyze column-bound proteins as well as corresponding changes in patients' sera.

RESULTS

After the third IA, we detected an improvement of vision in eight of eleven patients, whom we termed responders. Amongst these, the mean visual acuity improved from 0.15 ± 0.12 at baseline to 0.47 ± 0.32 after the third IA (P = 0.0252) up to 0.89 ± 0.15 (P < 0.0001) at day 180 ± 10 after IA. Soluble interleukin-2 receptor decreased in responders (P = 0.03), whereas in non-responders it did not. Proteomic analyses of proteins adsorbed to IA columns revealed that several significant immunological proteins as well as central nervous system protein fragments, including myelin basic protein, had been removed by IA.

CONCLUSIONS

IA was effective in the treatment of corticosteroid-refractory optic neuritis. IA influenced the humoral immune response. Strikingly, however, we found strong evidence that demyelination products and immunological mediators were also cleared from plasma by IA.

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

Available evidence on the effects of therapeutic plasmapheresis (TP) techniques and in particular lipid- and LDL-apheresis (LDL-a) on plasmatic inflammatory mediators including cytokines were reviewed. Studies on this issue are not numerous. However, the review of existing evidence clearly suggests an active role of apheresis on the profile of inflammatory molecules and on cytokine pattern in plasma. These non-lipid-lowering effects can be defined to some extent pleiotropic or pleiotropic-equivalent. Although further studies are desirable, the data reported in this review confirm that lipid- and LDL-a not only show acute lipid-lowering and cholesterol-lowering effects, but also efficacy in reducing several proinflammatory peptides, including cytokines. This effect was not related apparently to lipids and lipoproteins reduction. Thus, TP (lipid- and LDL-a), commonly utilized in the treatment of severe genetically determined lipid disorders, unresponsive to hypolipidemic drugs, offers new possibilities of interpretation of its role in the mechanisms leading to the blockade of atherosclerotic lesion development and progression. The ability of TP on short-term to induce such a profound change in the plasmatic metabolic and inflammatory profiles must be kept in mind in the treatment of acute coronary syndromes, before and after interventions of coronary revascularization, and in the acute phase of cerebrovascular ischemia, at least in patients with severe dyslipidemia. Further studies are needed, in particular aimed at assessing if circulating cytokines may be downregulated by TP not only by direct removal, but through indirect effects on both gene translation and transcription perhaps via the cytokine receptor function.

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.

LDL lipid apheresis rapidly increases peripheral endothelial progenitor cell competence

BACKGROUND AND AIM

Endothelial progenitor cells (EPCs) have been shown to promote neovascularization under physiologic and pathologic conditions. Statins have been documented to increase the total number of circulating EPCs in long-term treated patients. Lipid apheresis is used to treat patient with refractory hyperlipidemia. The aim of our study was to evaluate whether lipid apheresis is associated with EPC mobilization.

METHODS

Thirteen patients with refractory hyperlipidemia (analysis at the beginning and at the end of a single lipid apheresis treatment) and 10 healthy controls were included into the study. For quantifying total peripheral EPCs, CD133+/Flk-1+ myelo-monocytic blood cells were enumerated by flow cytometry. The proliferative potential of EPCs was evaluated by a "colony-forming unit" assay. In some patients, EPC eNOS expression was evaluated before and after treatment.

RESULTS

Circulating EPCs and the cells' proliferative activity were lower in hyperlipidemia patients as compared to controls (0.14 +/- 0.07 vs. 0.6 +/- 0.14, P = 0.01, and 13.9 +/- 4.9 vs. 45.6 +/- 8.1, P = 0.0007). Lipid apheresis treatment was not associated with an increase in total EPCs. The cells' proliferative activity was strongly stimulated by lipid apheresis as reflected by an increase in the number of EPC colonies (13.9 +/- 4.9 to 34.1 +/- 7.3, P = 0.035). Analysis of EPC eNOS expression revealed a threefold increase in the cellular expression intensity after lipid apheresis.

CONCLUSIONS

Patients with refractory hyperlipidemia exhibit lower peripheral EPC numbers and a lower proliferative activity of circulating EPCs than healthy controls. A single lipid apheresis treatment significantly stimulates EPC proliferation, it furthermore increases cellular eNOS. In summary, these results show that lipid apheresis mediates beneficial effects on the EPC system as an essential element in the process of vascular repair in the human organism.

Lipoprotein glomerulopathy treated with LDL-apheresis (Heparin-induced Extracorporeal Lipoprotein Precipitation system): a case report

Introduction

Lipoprotein glomerulopathy is a glomerulonephritis which was described for the first time by Saito in 1989 and is currently acknowledged as a separate nosological entity. It is histologically characterized by a marked dilatation of the glomerular capillaries and the presence of lipoprotein thrombi in the glomerular lumens. The dyslipidemic profile is similar to that of type III dyslipoproteinemia with Apolipoprotein E values that are often high; proteinuria and renal dysfunction are present. Proteinuria often does not respond to steroid and cytostatic treatments.

The phenotypic expression of lipoprotein glomerulopathy is most probably correlated to a genetic alteration of the lipoprotein metabolism (mutation of the Apolipoprotein E coding gene). In literature, lipoprotein glomerulopathies have mainly been reported in Japanese and Chinese subjects, except for three cases in the Caucasian race, reported in France and the USA.

Case presentation

We describe the case of a 60-year-old female, Caucasian patient suffering from lipoprotein glomerulopathy, carrier of a new mutation on the Apolipoprotein E gene (Apolipoprotein E_MODENA), and treated successfully with low density lipoprotein-apheresis with the Heparin induced extracorporeal lipoprotein precipitation system. After a first phase of therapeutic protocol with statins, the patient was admitted for nephrotic syndrome, renal failure and hypertension. Since conventional treatment alone was not able to control dyslipidemia, aphaeretic treatment with heparin-induced Extracorporeal Lipoprotein Precipitation - apheresis (HELP-apheresis) was started to maintain angiotensin converting enzyme inhibitor therapy for the treatment of hypertension. Treatment with HELP-apheresis led to a complete remission of the proteinuria in a very short time (four months), as well as control of hypercholesterolemia and renal function recovery.

Conclusion

According to this case of lipoprotein glomerulopathy, we believe that renal damage expressed by proteinuria correlates to the levels of lipids and, furthermore, the treatment with HELP-apheresis, by lowering low-density lipoprotein cholesterol and triglycerides, may be considered as a therapeutic option in synergy with pharmacological treatment in the treatment of lipoprotein glomerulopathy.