Plasma dependent reduction in red blood cell aggregation after dextran sulfate low-density lipoprotein apheresis--implications for rheological studies

Red blood cell (RBC) aggregation is increased in familial hypercholesterolemia, and is reduced significantly after low density lipoprotein (LDL) apheresis. The purpose of the present study was to clarify whether this reduction depends on changes in plasma composition, RBC membrane properties, or both. RBC aggregation was determined in a computerized cell flow-properties analyzer, before and after LDL apheresis. We compared RBC aggregation in autologous plasma with aggregation in a plasma-free standard solution (0.5% of dextran 500 kDa) to define the separate contributions of plasma and cellular properties to the observed RBC aggregation. RBC aggregation in autologous plasma was reduced by 35.5% after LDL apheresis (P=0.01) but was not significantly affected when measured in dextran 500. This suggests that LDL apheresis attenuated RBC aggregation by altering plasma composition rather than RBC membrane properties. These results are relevant to the understanding of hemorheological changes which follow therapeutic apheresis in hypercholesterolemic patients.     

Indication of low-density lipoprotein apheresis in severe hypercholesterolemia and its atherosclerotic vascular complications: dextran sulfate cellulose low-density lipoprotein apheresis

Homozygous familial hypercholesterolemia (FH) and heterozygous FH, with or without elevation of Lp(a), or isolated massive elevation of Lp(a) with clinically relevant coronary heart disease are indications for low-density lipoprotein (LDL) apheresis, as long as maximal conventional lipid lowering drug therapy does not lead to a LDL cholesterol level below 100 mg/dL. Reduction of lipoproteins and Lp(a), of oxidation of LDL, improvement of disturbed vasomotion, the procoagulatory state and disturbed hemorheology associated with atherosclerosis, as well as the stabilization of plaques and the decrease of cytokines and adhesion molecules have been induced by apheresis and are thought to favorably influence regression of artherosclerosis. Several intervention studies point in this direction.     

Direct adsorption of lipoproteins from whole blood by direct adsorption of lipoprotein apheresis: first experience in two hypercholesterolemic children

Low density lipoprotein (LDL) cholesterol apheresis, combined with lipid lowering drugs, provides a safe and effective means of improving the prognosis of patients with homozygote familial hypercholesterolemia, especially if started before the age of seven. The direct adsorption of lipoprotein (DALI) is the first extracorporeal low density lipoprotein removing system compatible with whole blood. The purpose of the present study was to clarify the efficacy and safety of DALI in children with homozygous familial hypercholesterolemia. Two boys, aged 9 and 15 years, with familial hypercholesterolemia, who were highly resistant to dietary regimes and to drug therapy, were treated with the low density lipoprotein adsorber DALI apheresis once every 2 weeks for 24 weeks. The treated blood volumes for each procedure were 2911 mL (493 +/- SD) and 5982 mL (1129 +/- SD), respectively. In our patients, the acute mean LDL cholesterol reductions were 44.7 +/- 8.9% and 58.8 +/- 4.5%. The corresponding reductions were 42.5 +/- 7.2% and 56 +/- 4.3% for total cholesterol, and 46.5 +/- 17.1% and 55 +/- 7.5% for very low density lipoprotein cholesterol (VLDL-C). There were insignificant losses of high density lipoprotein (12.2 +/- 5.7%, 8.3 +/- 5.5%). Treatment was well tolerated in general, and neither patient suffered from irreversible or long-lasting adverse effects. Our experience with DALI apheresis is encouraging. The present report is the first on the use of DALI in children. Based on this short-term evaluation we think that DALI might be safe and effective in children with homozygote familial hypercholesterolemia, however further evaluation of long-term effects is needed.     

The state of leukocyte adhesiveness/aggregation in the peripheral blood of patients with type 2 diabetes and ischemic vascular disease

White blood cells have a potential role in the pathogenesis of vasculopathy in diabetic patients. We studied the circulating peripheral blod in a cohort of patients with documented ischemic heart or brain disease with and without type 2 diabetes by means of image analysis and flow cytometry. Our study showed that the state of leukocyte adhesiveness/aggregation is slightly increased in those who had concomitant diabetes but that there was no difference regarding the expression of CD11b/CD18 and CD62L antigens on the surface of the peripheral blood white blood cells. The finding of a significantly increased number of white blood cells in the peripheral blood of patients with ischemic vascular diseases is important insofar as it is associated with a poorer prognosis. Received: 21 May 2000 / Accepted in revised form: 28 March 2001     

Image analysis for the detection of increased erythrocyte, leukocyte and platelet adhesiveness/aggregation in the peripheral blood of patients with diabetes mellitus

Increased erythrocyte, leukocyte, and platelet adhesiveness and aggregation may contribute to the development of ischemic vascular conditions in diabetic patients. They have been described by using different diagnostic systems and following various ex vivo manipulations. We have adopted a simple slide test and image analysis to reveal the adhesiveness and aggregation of the three cellular elements in a picture that is obtained from one single citrated venous blood sample presented on a glass slide. A significant increment in the degree of adhesiveness/aggregation of erythrocytes, leukocytes and platelets was noted in 29 patients with diabetes mellitus as opposed to age- and gender-matched healthy controls. It is feasible to look at the increased state of adhesiveness/aggregation of erythrocytes, leukocytes and platelets present in their native milieu and following minimal manipulation by using an almost real time and low cost procedure. Received: November 2000 / Accepted in revised form: June 2001     

Increased adhesiveness of peripheral blood leukocytes corresponds to the appearance of expansion following anterior wall myocardial infarction

The appearance of increased leukocyte adhesiveness/aggregation as an inflammatory marker in the peripheral blood of patients with anterior wall myocardial infarction was monitored. Of the 26 patients included in the study, 7 had infarct expansion as shown by an enlargement of left ventricular end-diastolic volume. The percent of aggregated leukocytes in the peripheral blood of patients with expansion (29.7 ± 15.5%) was significantly higher (p = 0.01) than that obtained from patients with no expansion (18.5 ± 6.8%). The lack of significant differences in peak creatine kinase concentrations between patients with and without expansion suggests that infarct size is not necessarily the main determinant for the appearance of expansion; an increased inflammatory reaction could be a contributory factor.     

Rheological determinants of red blood cell aggregation in diabetic patients in relation to their metabolic control.

AIMS: To determine whether increased red blood cell adhesiveness/aggregation in diabetic patients is related to the extent of their metabolic control. METHODS: We measured erythrocyte adhesiveness/aggregation in a group of 85 adult patients with diabetes mellitus by using citrated venous whole blood and a simple slide test. The erythrocyte adhesiveness/aggregation was determined by measuring the size of the spaces that are formed between the aggregated erythrocytes. We divided the patients into those with either low or high erythrocyte adhesiveness/aggregation values. RESULTS: The erythrocyte adhesiveness/aggregation values of the two groups differed significantly in terms of their fibrinogen concentration, erythrocyte sedimentation rate, high sensitive C-reactive protein (CRP), total cholesterol and triglyceride concentrations. There was no difference between the two groups regarding the concentrations of HbA(1c). Logistic regression was applied to construct a model to predict the belonging of a patient in the low or high erythrocyte adhesiveness/aggregation group. A linear regression was applied to construct a model to predict the erythrocyte adhesiveness/aggregation values. Both models turned out to include gender, age, fibrinogen, triglyceride, retinopathy, coronary artery disease and age and gender interaction. Neither HbA(1c) nor CRP entered the models. CONCLUSIONS: The degree of erythrocyte adhesiveness/aggregation and several variables of the acute-phase response in patients with diabetes mellitus are not directly related to the degree of metabolic control as evaluated by means of HbA(1c) concentration. Diabetic patients might benefit from rheological or anti-inflammatory interventions regardless of their metabolic control.     

First Steps Toward the Establishment of a German Low‐Density Lipoprotein‐Apheresis Registry: Recommendations for the Indication and for Quality Management

Abstract: New recommendations for the indication of treatment with selective extracorporeal plasma therapy low‐density lipoprotein apheresis (LDL‐apheresis) in the prevention of coronary heart disease are urgently needed. The following points are the first results of the ongoing discussion process for indications for LDL‐apheresis in Germany: all patients with homozygous familial hypercholesterolemia with functional or genetically determined lack or dysfunction of LDL receptors and plasma LDL cholesterol levels >13.0 mmol/L (>500 mg/dL); patients with coronary heart disease (CHD) documented by clinical symptoms and imaging procedures in which over a period of at least 3 months the plasma LDL cholesterol levels cannot be lowered below 3.3 mmol/L (130 mg/dL) by a generally accepted, maximal drug‐induced and documented therapy in combination with a cholesterol‐lowering diet; and patients with progression of their CHD documented by clinical symptoms and imaging procedures and repeated plasma Lp(a) levels >60 mg/dL, even if the plasma LDL cholesterol levels are lower than 3.3 mmol/L (130 mg/dL). Respective goals for LDL cholesterol concentrations for high‐risk patients have been recently defined by various international societies. To safely put into practice the recommendations for LDL‐apheresis previously mentioned, standardized treatment guidelines for LDL‐apheresis need to be established in Germany that should be supervised by an appropriate registry.     

Effects of Direct Adsorption of Lipoproteins Apheresis on Lipoproteins,Low‐Density Lipoprotein Subtypes,and Hemorheology in Hypercholesterolemic Patients with Coronary Artery Disease

Abstract: Direct adsorption of lipoproteins (DALI) apheresis has been shown to reduce effectively low‐density lipoprotein (LDL) cholesterol and lipoprotein (a) concentrations. However, the effects on nontraditional risk indicators such as hemorheology and LDL subtypes have not been investigated so far. Five patients (2 women, 3 men, age 53 ± 8 years) with coronary artery disease and severe LDL hypercholesterolemia regularly treated with other LDL apheresis devices entered the study and were then treated with DALI for the first time. Hemorheological and lipoprotein parameters were measured before and immediately after the initial DALI apheresis as well as before the fourth DALI apheresis. Compared to baseline (before the first DALI apheresis), the following parameters were significantly improved (p < 0.05) after the first DALI apheresis: LDL cholesterol (69 ± 28 versus 208 ± 82 mg/dl) and cholesterol in each LDL subfraction as well as plasma viscosity (1.23 ± 0.04 versus 1.37 ± 0.06 mPa), C‐reactive protein, native blood viscosity, red cell aggregation, and red cell deformability. When parameters before the fourth DALI apheresis were compared to baseline, LDL cholesterol was still lower, and red cell deformability was still improved while cholesterol in each subfraction showed a statistical trend to lower concentrations (0.08 < p < 0.14). In conclusion, DALI apheresis not only reduces LDL cholesterol but also induced a significant reduction of cholesterol in all LDL subfractions and improved various hemorheological parameters.     

Blood flow analysis of the head and lower limbs by the laser Doppler blood flowmeter during LDL apheresis

The presence of peripheral arterial disease substantially increases the risk for both morbidity and mortality among end-stage renal disease patients. Low-density lipoprotein (LDL) apheresis has been also applied for the treatment of peripheral arterial disease to reduce LDL levels, resulting in the improvement of the blood flow to the ischemic limbs. In this study, we investigated the continuous changes of the tissue blood flows in the lower limbs and head during LDL-apheresis treatment by a non-invasive method (the non-invasive continuous monitoring method (NICOMM) system). In this study, the tissue blood flow in both the head and lower limbs showed a significantly enhancement from before to after treatment. The tissue blood flow in the lower limbs showed a significantly larger improvement than that in the head. The short-term effects of LDL apheresis were confirmed by using the NICOMM system; thus, this system will be useful for the determination of the appropriate schedule of LDL apheresis for long-term effectiveness.     

State of the art of low-density lipoprotein apheresis in the year 2003

Low-density lipoprotein (LDL) apheresis is a last-resort treatment for hypercholesterolemic patients resistant to conservative lipid-lowering therapy. In the extracorporeal circuit, LDL, Lp(a) and coagulation factors are selectively eliminated, while the beneficial proteins like high-density lipoprotein, albumin and immunoglobulins are returned to the patient. Clinical effects of LDL apheresis comprise improvement of symptoms like angina and exercise tolerance, reduction of clinical coronary events like unstable angina, need for angioplasty or bypass operation, myocardial infarction and ultimately coronary mortality. The reduction of atherogenic lipoproteins and of coagulation factors by LDL apheresis (LA) positively influences hemorheology, endothelial function and coronary reserve. In the controlled LAARS, LA significantly improved the electrocardiographic signs of myocardial ischemia in the treadmill test. In angiographically controlled trials such as LARS and L-CAPS, a reduction of progression of coronary lesions was observed; in favorable cases, regression of the stenoses could be documented. In addition, in the LDL apheresis coronary morphology trial, LA decreased the coronary plaque area. The Hokuriku trial documented a 72% decrease of coronary events (MACE) in the LA group vs. controls treated only by statins. In longitudinal studies, the incidence of MACE after regular LA decreased compared with the preapheresis period in the same patients. Apart from coronary heart disease, recent studies indicate a positive effect of LA also on carotid artery stenoses and peripheral vascular disease. Prospective randomized studies showed the beneficial effects of cascade filtration on age-related macular degeneration and of heparin-induced LDL precipitation apheresis on acute inner ear deafness.     

Improvement of Hemorheology by DALI Apheresis: Acute Effects on Plasma Viscosity and Erythrocyte Aggregation in Hypercholesterolemic Patients

Abstract: Plasma viscosity (PV) and erythrocyte aggregation (EA) are determinants of microcirculation, especially under the compromised hemodynamic conditions resulting from atherosclerosis. Direct adsorption of lipoproteins (DALI) apheresis is the first method for direct adsorption of lipoproteins; it drastically reduces low‐density lipoprotein (LDL)‐cholesterol and lipoprotein (a) (Lp[a]), and may therefore improve PV and EA. The current study was performed to test the effect of DALI on hemorheology. Six hypercholesterolemic patients who had been on regular LDL apheresis for at least several months were treated on a weekly or biweekly basis, on average 5 times each by DALI. Before and after each session, PV was measured by a capillary tube plasma viscosimeter and EA by rotational aggregometry. Single DALI sessions (n = 31) acutely decreased PV from 1.18 ± 0.04 to 1.06 ± 0.3 mPa (?10%) while EA improved from 22.8 ± 4.4 to 13.3 ± 4.5 (arbitrary units) (?42%). LDL‐cholesterol, Lp(a), and very‐low‐density lipoprotein (VLDL)‐cholesterol were effectively reduced while the decrease of triglycerides and fibrinogen was only moderate. DALI apheresis exerted an acute positive effect on blood hemorheology which may have beneficial effects on microcirculation. This hypothesis is in accordance with the clinical observation that in some patients, improvement of angina and/or exercise tolerance can be observed after only a few DALI sessions where changes of coronary stenoses cannot be expected yet.     

The Erythrocyte Adhesiveness/Aggregation Test to Reveal Real‐Time Information of Rheological Relevance in Patients with Familial and Primary Hypercholesterolemia Before and Following Plasma Exchange

Abstract: We applied an erythrocyte adhesiveness/aggregation test (EAAT) to a model of plasma exchange in individuals with familial and primary hypercholesterolemia. The significant (p < 0.0001) reduction in the concentration of fibrinogen by 56%, globulins by 48%, and cholesterol by 53% corresponded to the expected significant (p < 0.0001) reduction in the degree of erythrocyte adhesiveness/aggregation in the peripheral venous blood. By virtue of its being a real‐time, simple, very‐low‐cost, and essentially bedside technique, the EAAT might have the potential of disclosing information of rheological relevance immediately before, during, as well as following apheretical procedures administered to patients with an impaired rheological profile.     

Increased erythrocyte adhesiveness/aggregation in the peripheral venous blood of patients with ischaemic heart disease and an eventful course

OBJECTIVE: To determine whether increased erythrocyte aggregability has prognostic implications in patients with established ischaemic heart disease. METHODS AND RESULTS: We have adopted a simple slide test and image analysis to reveal the state of erythrocyte adhesiveness/aggregation (EAA) in the peripheral blood of patients with ischaemic heart disease and an eventful course (n=46) as opposed to those with an uneventful (n=43) course. A significant correlation was noted between the results of the erythrocyte adhesiveness/aggregation test (EAAT) and either erythrocyte sedimentation or fibrinogen concentration. When we sampled the results of fibrinogen in the group of eventful course they were not significantly different from the results obtained in the uneventful one. This was the case with the results of the erythrocyte sedimentation rate. However, the variables of the EAAT showed a significant difference, the values in the eventful group being higher than those observed in the uneventful one. CONCLUSIONS: The EAAT is a valuable tool to disclose the presence of increased red blood cell aggregability in patients with ischaemic heart disease. Increased EAA might have prognostic implications in patients with ischaemic heart disease.     

Beneficial Effect of Endovascular Therapy and Low‐Density Lipoprotein Apheresis Combined Treatment in Hemodialysis Patients With Critical Limb Ischemia due to Below‐Knee Arterial Lesions

To assess the clinical benefit of combined treatment of below‐knee endovascular therapy (BK‐EVT) plus low‐density lipoprotein apheresis (LDLA) compared with BK‐EVT monotherapy, we retrospectively evaluated the clinical outcome of hemodialysis (HD) patients with critical limb ischemia (CLI) due to isolated BK arterial lesions who underwent BK‐EVT or BK‐EVT plus short‐term LDLA. Between October 2011 and September 2014, 62 HD patients underwent isolated BK‐EVT monotherapy (BK‐EVT group), and 25 HD patients underwent BK‐EVT plus LDLA (BK‐EVT + LDLA group). LDLA was started within 1 week after BK‐EVT and performed four times in total within next 2 weeks. Major adverse limb events (MALE) including major amputation and re‐intervention, and all‐cause mortality were examined by Kaplan–Meier method and the log‐rank test. Baseline characteristics were not different other than low ABI and low dorsal SPP in BK‐EVT + LDLA group. Cumulative MALE‐free rate was significantly improved in BK‐EVT + LDLA group over the BK‐EVT group (72.0% and 45.1% respectively at 30 months after treatment, P = 0.04). All‐cause mortality did not differ between the two groups. Major causes of death were heart failure and sepsis in both groups. Short‐term LDLA hybrid treatment immediately after BK‐EVT might improve the outcome of ischemic limbs after re‐vascularization therapy.     

Rapid and Persistent Reduction of Proteinuria Following Plasma Exchange in a Case of Steroid‐Resistant Focal Segmental Glomerulosclerosis

Abstract: We report on the case of a 45 year old male with focal segmental glomerulosclerosis (FSGS) in whom steroid‐resistant proteinuria was reduced rapidly by plasma exchange. In 1994, he was admitted to our hospital because of massive proteinuria of several years' duration. Renal biopsy confirmed the diagnosis of FSGS. Proteinuria was suppressed partially with the use of dipyridamole. Though oral prednisolone (PSL, 30 mg/day) was effective initially, relapse occurred during PSL tapering. Doses of PSL up to 30 mg/day or additional mizoribine were ineffective. The patient was readmitted for a trial of plasma exchange in April 2000. Four sessions of plasma exchange with albumin replacement over 2 weeks immediately reduced the proteinuria from 3.2 g/day to 0.6 g/day without any change in medication. After discharge, proteinuria remained suppressed for more than 6 months despite a reduction of PSL dose to 15 mg. The rapid and long lasting effect of plasma exchange in the present case argues for the role of a putative circulatory factor in the pathogenesis of proteinuria in FSGS.     

A case report of the cascade filtration system: a safe and effective method for low-density lipoprotein apheresis during pregnancy

Women with familial hypercholesterolemia (FH) should be treated effectively during pregnancy, as elevated low-density lipoprotein cholesterol (LDL-C) levels may result in life-threatening consequences. Hydroxymethylglutaryl-coenzyme A reductase inhibitors are contraindicated during pregnancy, therefore LDL apheresis should be considered in the management of such pregnant cases. There are five different methods of selective LDL apheresis: heparin-induced extracorporeal LDL precipitation, double filtration plasmapheresis, direct adsorption of lipoproteins, dextran sulfate adsorption, and LDL immunoadsorption. The cascade filtration system is another modern and effective method for the extracorporeal elimination of LDL-C, although it is not as selective as the methods mentioned above. Herein, we present the case of a pregnant woman with heterozygous FH and extremely elevated LDL-C levels who has been successfully treated with the cascade filtration system until delivery. As far as we can ascertain, LDL apheresis with the cascade filtration system during pregnancy has not yet been reported in the literature.     

Influence of Atorvastatin Versus Simvastatin on Fibrinogen and Other Hemorheological Parameters in Patients with Severe Hypercholesterolemia Treated with Regular Low‐Density Lipoprotein Immunoadsorption Apheresis

Abstract: Low‐density lipoprotein (LDL) apheresis is a treatment option in patients with coronary artery disease and elevated LDL cholesterol concentrations if maximal drug therapy fails to achieve adequate LDL cholesterol reduction. This therapy is more effective when combined with strong lipid‐lowering drugs, such as atorvastatin. However, conflicting data have been published concerning the effect of atorvastatin on fibrinogen concentration. Therefore, we investigated the effect of atorvastatin compared to simvastatin on fibrinogen concentration and other hemorheological parameters in patients treated by weekly LDL apheresis. Hemorheological parameters were, studied twice in 9 patients (4 female, 5 male, 54.0 ± 8.9 years) with coronary artery disease treated by weekly LDL immunoadsorption, once during concomitant simvastatin therapy (40 mg daily) and once during atorvastatin therapy (40 mg daily). Fibrinogen concentration, plasma and blood viscosity at different shear rates, parameters of red cell aggregation at stasis and shear rate 3/s, and erythrocyte filterability were determined 7 days after the last LDL apheresis after each drug had been given for a minimum for 8 weeks. Fibrinogen concentration did not show any statistically significant difference during therapy with atorvastatin (3.09 ± 0.36 g/L) compared to simvastatin (3.13 ± 0.77 g/L). Plasma and blood viscosity as well as erythrocyte filterability were also unchanged. The increase in red cell aggregation at stasis during atorvastatin treatment (5.82 ± 1.00 U versus 4.89±0.48 U during simvastatin; p < 0.05) was inversely correlated with a lower high‐density liprotein (HDL) cholesterol concentration (1.17 ± 0.21 mmol/L versus 1.31 ± 0.30 mmol/L during simvastatin; p < 0.05). LDL cholesterol showed a strong trend to lower concentrations during atorvastatin (4.14 ± 0.61 mmol/L versus 4.56 ± 0.66 mmol/L during simvastatin; p = 0.07), despite a reduced plasma volume treated (3,547 ± 1,239 ml during atorvastatin versus 3,888 ± 1,206 mL during simvastatin; p < 0.05). In conclusion, fibrinogen concentration and other hemorheological parameters were unchanged during atorvastatin compared to simvastatin therapy with the exception of a higher red cell aggregation at stasis. Therefore, with respect to hemorheology, we conclude that atorvastatin should not be withheld from hypercholesterolemic patients regularly treated with LDL immunoadsorption.     

Proteomics Approach Identifies Factors Associated With the Response to Low‐Density Lipoprotein Apheresis Therapy in Patients With Steroid‐Resistant Nephrotic Syndrome

Low‐density lipoprotein apheresis (LDL‐A) has been shown to reduce proteinuria in a subgroup of nephrotic syndrome patients refractory to immunosuppressive therapy. Factors influencing the efficacy of LDL‐A in nephrotic syndrome are completely unknown. Using a proteomics approach, we aimed to identify biological markers that predict the response to LDL‐A in patients with steroid‐resistant nephrotic syndrome (SRNS). Identification of plasma proteins bound to the dextran‐sulfate column at the first session of LDL‐A was determined by mass spectrometry. To investigate biological factors associated with the response to LDL‐A, we compared profiles of column‐bound proteins between responders (defined by more than 50% reduction of proteinuria after the treatment) and non‐responders by 2‐dimensional gel electrophoresis (2‐DE) coupled to mass spectrometry in seven patients with SRNS. Evaluation of proteins adsorbed to LDL‐A column in patients with SRNS revealed the identity of 62 proteins, which included apolipoproteins, complement components, and serum amyloid P‐component (SAP). Comparative analysis of the column‐bound proteins between responders and non‐responders by 2‐DE demonstrated that apolipoprotein E (APOE) and SAP levels were increased in non‐responders as compared with responders. These results were confirmed by western blotting. Moreover, serum levels of APOE and SAP were significantly higher in the non‐responder group than in the responder group by ELISA. Our data provide comprehensive analysis of proteins adsorbed by LDL‐A in SRNS, and demonstrate that the serum levels of APOE and SAP may be used to predict the response to LDL‐A in these patients.