Effects of selective LDL apheresis on plasma concentrations of ICAM-1, VCAM-1 and P-selectin in diabetic patients with arteriosclerosis obliterans and receiving maintenance hemodialysis

Pleiotropic effects of double filtration plasmapheresis

Double filtration plasmapheresis (DFPP) is a semi-selective blood purification modality derived from the plasma exchange modality. DFPP can be applied to a variety of refractory disorders including metabolic disorders, organ transplants, rheumatic disorders, neurological disorders, and dermatologic disorders. Familial hypercholesterolemia and lipoprotein (a) hyperlipoproteinemia are major chronic metabolic disorders. Lipoprotein apheresis (LA) is applied for those patients to remove low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) (Lp(a)). DFPP is used as one of the modalities in LA. In addition to removing LDL-C and Lp(a), DFPP has pleiotropic effects such as removal of lipid metabolism-related substances, C-reactive protein lowering effect, removal of adhesion molecules, removal of inflammatory cytokines, and anti-oxidative effect. This article summarizes the pleiotropic effects of DFPP based on recent clinical articles.

Clinical practice recommendations on lipoprotein apheresis for children with homozygous familial hypercholesterolaemia: An expert consensus statement from ERKNet and ESPN

Homozygous familial hypercholesterolaemia is a life-threatening genetic condition, which causes extremely elevated LDL-C levels and atherosclerotic cardiovascular disease very early in life. It is vital to start effective lipid-lowering treatment from diagnosis onwards. Even with dietary and current multimodal pharmaceutical lipid-lowering therapies, LDL-C treatment goals cannot be achieved in many children. Lipoprotein apheresis is an extracorporeal lipid-lowering treatment, which is used for decades, lowering serum LDL-C levels by more than 70% directly after the treatment. Data on the use of lipoprotein apheresis in children with homozygous familial hypercholesterolaemia mainly consists of case-reports and case-series, precluding strong evidence-based guidelines. We present a consensus statement on lipoprotein apheresis in children based on the current available evidence and opinions from experts in lipoprotein apheresis from over the world. It comprises practical statements regarding the indication, methods, treatment goals and follow-up of lipoprotein apheresis in children with homozygous familial hypercholesterolaemia and on the role of lipoprotein(a) and liver transplantation.

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.

Rheopheresis Performed in Hemodialysis Patients Targets Endothelium and Has an Acute Anti-Inflammatory Effect

Background: Rheopheresis is a double-filtration plasmapheresis that removes a defined spectrum of high-molecular-weight proteins to lower plasma viscosity and improves microcirculation disorders. This technique can be performed in hemodialysis (HD) patients with severe microischemia. Interestingly, some studies showed that rheopheresis sessions improve endothelial function. Methods: Our study evaluated the inflammatory and endothelial biomarker evolution in 23 HD patients treated or not with rheopheresis. A p value ≤ 0.001 was considered statistically significant. Results: Thirteen HD patients treated by rheopheresis either for a severe peripheral arterial disease (N = 8) or calciphylaxis (N = 5) were analyzed. Ten control HD patients were also included in order to avoid any misinterpretation of the rheopheresis effects in regard to the HD circuit. In the HD group without rheopheresis, the circulating endothelial adhesion molecules, cytokines, angiogenic factor concentrations, and circulating levels were not modified. In the HD group with rheopheresis, the circulating endothelial adhesion molecules (sVCAM-1, sP-selectin, and sE-selectin) experienced a significant reduction, except sICAM-1. Among the pro-inflammatory cytokines, TNF-α was significantly reduced by 32.6% [(−42.2)−(−22.5)] (p < 0.0001), while the anti-inflammatory cytokine IL-10 increased by 674% (306−1299) (p < 0.0001). Among the angiogenic factors, only sEndoglin experienced a significant reduction. The CEC level trended to increase from 13 (3−33) cells/mL to 43 (8−140) cells/mL (p = 0.002). We did not observe any difference on the pre-session values of the molecules of interest between the first rheopheresis session and the last rheopheresis session. Conclusion: Rheopheresis immediately modified the inflammation balance and the endothelial injury biomarkers. Further studies are needed to understand the mechanisms underlying these biological observations.

Monitoring of up to 15 years effects of lipoprotein apheresis on lipids, biomarkers of inflammation, and soluble endoglin in familial hypercholesterolemia patients

Background

Lipoprotein apheresis (LA) is considered as an add-on therapy for patients with familial hypercholesterolemia (FH). We aimed to analyze the data collected in the last 15 years from FH patients treated with LA, to elucidate the benefit of this procedure with respect to plasma lipids, biomarkers of inflammation, and endothelial dysfunction and soluble endoglin.

Results

14 patients (10 heterozygous FH patients (HeFH), 4 homozygous FH patients (HoFH)) were treated by long-term lipoprotein apheresis. Lipid levels were examined, and ELISA detected biomarkers of inflammation and soluble endoglin. Paired tests were used for intergroup comparisons, and a linear regression model served to estimate the influence of the number of days patients were treated with LA on the studied parameters. LA treatment was associated with a significant decrease of total cholesterol (TC), LDL-C, HDL-C, and apoB, in both HeFH and HoFH patients, after single apheresis and in a long-term period during the monitored interval of 15 years. Biomarkers of inflammation and endothelial dysfunction were reduced for soluble endoglin, hsCRP, and MCP-1, and sP-selectin after each procedure in some HeFH and HoFH patients.

Conclusions

LA treatment up to 15 years, reduced cholesterol levels, levels of biomarkers related to endothelial dysfunction, and inflammation not only after each procedure but also in the long-term evaluation in FH patients. We propose that long-term LA treatment improves lipid profile and endothelial dysfunction in familial hypercholesterolemia patients, suggesting a promising improvement in cardiovascular prognosis in most FH patients.

Familial Hypercholesterolemia and Lipoprotein Apheresis

Lipoprotein apheresis has been developed as the treatment for refractory familial hypercholesterolemia (FH) to remove low-density lipoprotein (LDL), which is the main pathogenic factor. Currently, three procedures are available in Japan, including the plasma exchange, double-membrane filtration, and selective LDL adsorption. Selective LDL adsorption, which was developed in Japan, has been one of the most common treatment methods in the world. Lipoprotein apheresis enabled the prevention of atherosclerosis progression even in homozygous FH (HoFH) patients. However, in our observational study, HoFH patients who started lipoprotein apheresis in adulthood had a poorer prognosis than those who started in childhood. Therefore, HoFH patients need to start lipoprotein apheresis as early as possible. Although the indication for lipoprotein apheresis in heterozygous FH (HeFH) patients has been decreasing with the advent of strong statins, our observational study showed that HeFH patients who discontinued lipoprotein apheresis had a poorer prognosis than patients who continued apheresis therapy. These results suggest that it is beneficial for very-high-risk HeFH patients to be treated by lipoprotein apheresis even if their LDL cholesterol is controlled well by lipid-lowering agents. Since launching a new class of lipid-lowering agents, proprotein convertase subtilisin/kexin type 9 (PCSK9) antibody and microsome triglyceride transfer protein inhibitors, the indication for lipoprotein apheresis in FH has been changing. However, despite the development of these drugs, lipoprotein apheresis is still an option with a high therapeutic effect for FH patients with severe atherosclerotic cardiovascular disease.

Pleiotropic effects of regular lipoprotein-apheresis

BACKGROUND

Lipoprotein(LP)-apheresis is the treatment of choice in patients suffering from severe familial hypercholesterolemia. A wide range of mechanisms has been claimed to be responsible for the known clinical benefit.

METHODS

Patients suffering from heterozygous familial hypercholesterolemia undergoing LP-apheresis either with direct adsorption of lipoproteins (DALI) or dextran sulfate (DS) were examined. A total volume of 10 l blood was exchanged. Non-lipid effects, mainly concerning endothelial function (circulating endothelial cells, circulating endothelial progenitor cells, flow-mediated vasodilation, microalbuminuria) as well as left ventricular ejection fraction and homocysteine were assessed.

RESULTS

A single LP-apheresis session improves paradox contractile response in statin intolerant patients, but not in those on regular statin therapy. In contrast, over a 6-months follow-up after treatment initiation, all the examined parameters (circulating endothelial cells, circulating endothelial progenitor cells, flow mediated vasodilatation, homocysteine, microalbuminuria and left ventricular ejection fraction) improved. When available, a comparison between DS vs. DALI was performed. In none of the subgroups a significant difference was noted.

DISCUSSION

These findings indicate that beyond the well known lipid/lipoprotein lowering action the broad spectrum of functional tests examined reflecting mainly endothelial function is significantly improved by LP-apheresis treatment on the long-term and seems to be a key underlying reason for the clinical improvement seen in these patients.

Impact of double filtration plasmapheresis on adhesion molecules levels in patients with stable coronary heart disease after coronary stenting

OBJECTIVE AND METHODS

Endothelial dysfunction and inflammatory reaction at the site of damage plays a key role in the formation of neointimal hyperplasia, and in the progression of atherosclerosis. The initiating role in these processes is assigned to adhesion molecules. We studied the dynamics of the level of adhesion molecules soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), soluble form of the molecule platelet adhesion and endothelial type-1 (sPECAM-1), sL-, sP-, sE-selectins during double filtration plasmapheresis (DFPP) with use of plasma fractionators (PF) Cascadeflo EC-50W and EC-40W (Asahi Kasei Medical Co., Japan) in patients with stable coronary heart disease and hyperlipidemia-(a) in the early post-implantation period after coronary stenting.

RESULTS

DFPP reduces the level of plasma adhesion molecules. When using PF Cascadeflo EC-40W, a more pronounced decrease occurs. The rejection coefficient (RC) of adhesion molecules has been identified for these PF. These RCs reflect the immediate removal efficiency of adhesion molecules in the perfusion of plasma through PF. The removal effectiveness of adhesion molecules when using PF Cascadeflo EC-40W is higher than when using the PF Cascadeflo EC-50W (sICAM-1 - 2.5 times, sVCAM-1 - 2.2 times, sPECAM-1.6 times, sL-selectin - 5 times, sP-selectin - 2.8 times, sE - selectin - 3 times).

CONCLUSION

Reducing adhesion molecule levels when using DFPP may play an important role in correcting of endothelial dysfunction in response to damage to the arterial wall in percutaneous coronary intervention (PCI) during the early post-implantation period after coronary stenting. DFPP is a promising approach to prevent in-stent restenosis (ISR).

Soluble adhesion molecules as markers of native arteriovenous fistula thrombosis in children on uremia

Vascular access represents a lifeline for children undergoing hemodialysis. A failure of vascular access among patients receiving regular hemodialysis is associated with increased morbidity, mortality and costs. We assessed the possibility of using soluble adhesion molecules as reliable predictors of vascular access failure in children on hemodialysis. Moreover, we evaluated whether there is an association among the different studied adhesion molecules in hemodialysis patients with thrombosed and non-thrombosed arteriovenous fistula fistulas (AVFs). This study included 55 hemodialysis children, 36 with good access and 19 with access failure, and 20 healthy volunteers. Forty-four patients had native AVFs and 11 patients had tunneled permanent catheter (11with thrombosed and 33 with non-thrombosed AVFs). Serum-soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), soluble E-selectin (sE-selectin) and soluble P-selectin (sP-selectin) were measured using ELISA technique. A significant increase was found in the levels of sVCAM-1, sICAM-1, sE-selectin and sP-selectin versus controls and all hemodialysis patients, hemodialysis patients with good access and hemodialysis patients with access failure (P=0.001 for sVCAM-1 and sICAM-1 and P=0.0001 for sE-selectin and sP-selectin). A significant increase was found in the levels of sVCAM-1, sE-selectin and sP-selectin in both chronic hemodialysis patients with thrombosed and non-thrombosed native AVFs versus controls (P=0.0001 for all parameters). There was significant difference between both chronic hemodialysis patients with thrombosed and non-thrombosed native AVFs as regard to sVCAM-1 (54.64±30.82 versus 25.69±27.96ng/ml, P=0.04). Both sICAM-1 and sP-selectin were positively correlated with the erythropoietin (EPO) dose in hemodialysis children (r=0.31, P=0.04 and r=0.32, P=0.04, respectively). A significant positive association was found between E-selectin and sP-selectin in hemodialysis patients with thrombosed AVFs (r=0.83, P=0.04). There was a significant correlation between sVCAM-1 and EPO dose in thrombosed AVF group (r=0.84, P=0.01). The assessment of serum sVCAM-1 might be useful for the identification of the chronic hemodialysis patients at an increased risk for native AVFs thrombosis. The role of EPO in vascular access failure should be taken into consideration. The clinical relevance of these observations warrants further investigations.

Hybrid revascularization for critical limb ischemia triggered by multiple organ dysfunction due to acute pneumonia; urgent catheter intervention followed by low-density-lipoprotein apheresis and elective peripheral bypass surgery

A 66-year-old man was referred for treatment of critical limb ischemia arising with multiple organ dysfunction due to acute pneumonia. Angiographic examinations demonstrated total obstruction of the bilateral external iliac arteries and the bilateral superficial femoral arteries with collateral circulation to the distal vessels. Urgent percutaneous transluminal angioplasty dissolved the obstruction of the left external iliac artery, and subsequent low-density-lipoprotein apheresis ameliorated his progressive ischemia in the lower extremities. Femoro-femoral and bilateral femoro-popliteal bypasses were performed 31 days after the endovascular intervention, which achieved successful limb salvage with the relief of ischemic symptoms related to arteriosclerotic obliterans.

Lipoprotein apheresis of hypercholesterolemic patients mediates vasoprotective gene expression in human endothelial cells

OBJECTIVE

Hypercholesterolemia is an important risk factor of cardiovascular diseases. Lipoprotein apheresis is an efficient strategy to reduce the serum low-density lipoprotein (LDL)-cholesterol and lipoprotein(a) levels and cardiovascular complications in patients with severe hypercholesterolemia. The underlying molecular mechanisms are not well-understood. In this study, we analyzed the impact of lipoprotein apheresis on gene expression in human endothelial cells.

METHODS

Human endothelial cells were stimulated with serum of hypercholesterolemic patients before and after lipoprotein apheresis. The expression of endothelial lipoprotein receptors, nitric oxide (NO) synthase and adhesion molecules was quantified by real-time PCR and Western blot.

RESULTS

Lipoprotein apheresis reduced the expression of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in endothelial cells. Low-density lipoprotein (LDL) receptor expression remained unchanged. The mRNA expression of the endothelial nitric oxide synthase (eNOS) was increased with serum of hypercholesterolemic patients after lipoprotein apheresis. In contrast, endothelial expression of vascular cell adhesion molecule 1 (VCAM-1) was reduced in response to serum after lipoprotein apheresis.

CONCLUSION

Lipoprotein apheresis reduced the expression of the proatherosclerotic oxLDL receptor LOX-1 and adhesion molecule VCAM-1 and increased the expression of vasoprotective and NO generating eNOS in human endothelial cells in response to serum of hypercholesterolemic patients. These novel molecular mechanisms may account for the antiatherosclerotic and vasoprotective potential of lipoprotein apheresis in patients with hypercholesterolemia.

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.

Applications of LDL-apheresis in nephrology

LDL-apheresis (LA) was originally used for familial hyperlipidemia, and then in Japan extended to use for the treatment of patients with peripheral arterial disease (PAD) and nephrotic syndrome due to steroid-resistant focal glomerular sclerosis (FGS). The reason why this treatment is applicable for these disorders is due to the fact that LA exerts its favorable effects beyond the lipid-lowering effect. The main underlying mechanisms, for example, in the case of LA application in patients with PAD are: (1) improvement of hemorheology, (2) improvement of endothelial dysfunction, (3) elevations of serum levels of NO and bradykinin, (4) increase in serum levels of vascular endothelial growth factor, and (5) reduction of adhesion molecules on monocytes. Furthermore, we have reported that LA could have anti-inflammatory effects because LA reduces serum levels of P-selectin, which is known to play an important role in the development of atherosclerosis as well as a reduction of serum C-reactive protein levels as standard biomarker of atherosclerosis. Massive proteinuria is also an important challenge in nephrology. The possible mechanisms besides removal of toxic lipids are the reduction of the vasoconstrictive prostanoid and thromboxane A2 (TXA2) and an improvement in macrophage function evidenced by a significant amelioration of interleukin-8 production by lipopolysaccharide-stimulated peripheral blood mononuclear cells. It is intriguing to note that in terms of pharmacodynamics, LA improves steroid and cyclosporine uptake into lymphocytes. Although there are no randomized controlled trials, it is clear that LA has various effects beyond lowering lipids. Making the device more concise and changing it into a whole blood adsorption type, we need to collect more clinical cases and to study the underlying mechanisms further.

Clinical and genetic correlates of soluble P-selectin in the community

BACKGROUND

P-selectin is a cell adhesion molecule that is involved in atherogenesis, and soluble concentrations of this biomarker reflect cardiovascular risk. However, the clinical correlates and genetic characterization of soluble P-selectin have not been clearly elucidated.

OBJECTIVE

To describe clinical and genetic correlates of circulating P-selectin in the community.

METHODS

In Framingham Heart Study Offspring (European descent) and Omni (ethnic/racial minority) participants, we examined the association of cardiovascular risk factors with soluble P-selectin concentrations. In Offspring participants, we evaluated heritability, linkage and association of 29 SELP single-nucleotide polymorphisms (SNPs) with adjusted P-selectin concentrations.

RESULTS

In multivariable analysis of 3,690 participants (54% women, mean age 60 +/- 10 years), higher log-transformed P-selectin concentrations were inversely associated with female sex and hormone replacement therapy, and positively associated with age, ethnic/racial minority status, cigarette smoking, waist circumference, systolic blood pressure, fasting glucose, and total/high-density lipoprotein cholesterol and triglyceride concentrations. Clinical factors explained 10.4% of the interindividual variability in P-selectin concentrations. In 571 extended pedigrees (n = 1,841) with >or= 2 phenotyped members per family, multivariable-adjusted heritability was 45.4 +/- 5.8%. Among the SELP SNPs examined, a non-synonymous SNP (rs6136) encoding a threonine-to-proline substitution at position 715 was highly significantly associated with decreased P-selectin concentrations (P = 5.2 x 10(-39)), explaining 9.7% of variation after adjustment for clinical factors.

CONCLUSIONS

Multiple clinical factors and an SNP in the SELP gene were significantly associated with circulating P-selectin concentrations. One SNP in SELP explained significant variation in circulating P-selectin concentrations, even after accounting for known clinical correlates.

Targeting endothelial cells with heme oxygenase-1 gene using VE-cadherin promoter attenuates hyperglycemia-mediated cell injury and apoptosis

Risk factors for cardiovascular diseases include hyperglycemia, TNF, and reactive oxygen species (ROS), which collectively contribute to vascular endothelial cell dysfunction and apoptosis. We examined, in vascular endothelial cells, whether the selective expression of heme oxygenase-1 (HO-1) offers cytoprotection against glucose- and TNF-mediated cell death. An adenoviral vector expressing human HO-1 was constructed using a VE-cadherin (VECAD) promotor fragment, and cell-specific expression of the recombinant adenovirus was examined using endothelial and vascular smooth muscle cells. The effects of HO-1 transduction (Ad-VECAD-HO-1 gene) on HO-1 expression, HO activity, and the response to TNF and hyperglycemia were studied. Human HO-1 gene was selectively expressed in endothelial cells after infection with the Ad-VECAD-HO-1 vector. Selective expression of HO-1 prevented TNF- and hyperglycemia-mediated superoxide (O2-) formation, DNA degeneration, and upregulation of caspase, but increased the expression of pAkt and Bcl-xL, proteins responsible for endothelial dysfunction in diabetes. These results demonstrate that endothelial cell survival after oxidative stress injury may be enhanced by targeting HO-1 expression, thus blocking inflammation, apoptosis, and thereby attenuating cardiovascular risk factors.