DALI low-density lipoprotein apheresis in homozygous and heterozygous familial hypercholesterolemic patients using low-dose citrate anticoagulation.

The purpose of this study was to clarify the efficacy and safety of direct adsorption of lipoprotein low-density lipoprotein apheresis (DALI LDL apheresis) in patients with severe homozygous and heterozygous familial hypercholesterolemia who showed minor adverse effects during treatment with the usual DALI configuration (AC 1:20) through the use of a new system with low-dose citrate anticoagulation (AC 1:40) developed in order to minimize citrate-related adverse effects. Serum total cholesterol and LDL-cholesterol (LDL-C) showed a decrease of 57% to 61%, and 62% to 67%, respectively, in the 2 patients. Serum lipoprotein (a) (Lp[a]) was higher in the homozygous patient (Patient 1: MD) and within the normal range in the heterozygous patient (Patient 2: ES). In the former, Lp(a) was reduced by 52%. Serum high-density lipoprotein cholesterol (HDL-C) showed a statistically insignificant acute reduction: 15% to 19%. The observed reduction is mainly related to the well-known effect of hemodilution. The cardiovascular risk (total cholesterol/HDL-C) was reduced in both patients (46% to 54%) as expected. Serum triglycerides were reduced by 33% to 49%. The mean blood volume processed per session was 7,600 ml. Fifteen treatments for each patient have successfully been completed without the appearance of any clinically significant subjective and objective symptoms related to treatment with the new system.     

Reduction in cholesterol and low density lipoprotein synthesis after portacaval shunt surgery in a patient with homozygous familial hypercholesterolemia.

The turnover of 125I-labeled low density lipoprotein (LDL) and the total body balance of cholestrol were studied in a 6-yr-old girl with the homozygous form of familial hypercholesterolemia (FH) before and after the surgical creation of an end-to-side portacaval shunt. The results were compared with those of similar studies simultaneously performed in untreated patients with the heterozygous form of FH and with the results of earlier studies performed on normolipidemic subjects. Before shunt surgery, the rate of synthesis of LDL in the FH homozygote (mg/kg per day) was fourfold higher than in normolipidemic subjects and twofold higher than in her heterozygous mother. The fractional catabolic rate for LDL in the homozygote was decreased to 33% of normal control values. The rate of cholesterol synthesis, estimated by chemical sterol balance, was higher in the FH homozygote than in two FH heterozygotes of similar age studied simultaneously. When considered in relation to the markedly elevated level of plasma cholesterol, the observed rate of cholesterol synthesis in the FH homozygote was inappropriately elevated. Bile acid production was normal in all three children. 5 mo after shunt surgery, the rate of LDL synthesis in the homozygote had declined by 48% as compared with the preoperative value, and this caused a 39% drop in the plasma LDL cholesterol level despite a 17% reduction in the fractional catabolic rate of the lipoprotein. The rate of cholesterol synthesis fell by 62% as compared with the preoperative value. The findings of an inappropriately elevated rate of production of both cholesterol and LDL as well as a reduced fractional catabolic rate for the lipoprotein in the untreated FH homozygote are consistent with results of studies in cultured fibroblasts indicating that the primary genetic defect in FH involves a deficiency in a cell-surface receptor for LDL that regulates both cholesterol synthesis and LDL degradation. Although the mechanism for the decline in production of cholesterol and LDL after portacaval shunt surgery is unknown, it was observed that these changes were associated with marked increases in the plasma concentrations of bile acids and glucagon.     

Comparison of two low‐density lipoprotein apheresis systems in patients with homozygous familial hypercholesterolemia

Low‐density lipoprotein ( LDL) apheresis (LA) is a reliable method to decrease LDL‐C concentrations and remains the gold standard therapy in homozygous familial hypercholesterolemia (HoFH). The objective of this study was to compare the efficacy of two LA systems [heparin‐induced extracorporeal LDL precipitation (HELP) vs. dextran sulfate adsorption (DS) on the reduction of lipids, inflammatory markers, and adhesion molecules in a sample of genetically defined HoFH subjects (n = 9)]. Fasting blood samples were collected before and after LA. All subjects served as their own control and were first treated with the HELP system then with DS in this single sequence study. Compared with HELP, DS led to significantly greater reductions in total cholesterol (?63.3% vs. ?59.9%; P = 0.05), LDL‐C (?70.5% vs. ?63.0%; P = 0.02), CRP (?75.3% vs. ?48.8%; P < 0.0001), and TNF‐α (?23.7% vs. +14.7%; P = 0.003). Reductions in the plasma levels of PCSK9 (?45.3% vs. ?63.4%; P = 0.31), lipoprotein (a) (?70.6% vs. ?65.0%; P = 0.30), E‐selectin (?16.6% vs. ?18.3%; P = 0.65), ICAM‐1 (?4.0 vs. 5.6%; P = 0.56), and VCAM‐1 (8.3% vs. ?1.8%; P = 0.08) were not different between the two systems. For the same volume of filtered plasma (3,000 mL), however, HELP led to greater reductions in plasma apoB (?63.1% vs. ?58.3%; P = 0.04), HDL‐C (?20.6% vs. ?6.5%; P = 0.003), and PCSK9 (?63.4% vs. ?28.5%; P = 0.02) levels. These results suggest that both LA systems are effective in reducing plasma lipids and inflammatory markers in HoFH. Compared with HELP, greater reductions in lipid levels and inflammatory markers were achieved with DS, most likely because this method allows for a larger plasma volume to be filtered. J. Clin. Apheresis 31:359–367, 2016. © 2015 Wiley Periodicals, Inc.     

Three different LDL apheresis columns efficiently and equally reduce lipoprotein(a) concentrations in patients with familial hypercholesterolemia and small apolipoprotein(a) particles

Introduction

High levels of lipoprotein(a) [Lp(a)] and apolipoprotein(a) [apo(a)] are associated with cardiovascular disease. In this study we determined apo(a) particle size and compared the Lp(a) reducing efficacy of three different LDL apheresis columns; DL-75, LA-15 and EC-50W in patients with familial hypercholesterolemia (FH).

Results

Average Lp(a) concentration was reduced by 70%, 74% and 75% (all p < 0.0001) for DL-75, LA-15 and EC-50W, respectively. No significant changes in the relative proportion of the isoforms of 14 and 32 K 4 domains were observed after apheresis.

Conclusion

Three different LDL apheresis columns reduced Lp(a) efficiently with preserved ratio between apo(a) isoforms.     

The effect of selective low-density lipoprotein apheresis on plasma lipoperoxides and antioxidant vitamins in familial hypercholesterolemic patients.

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder characterized by a lifelong elevation in the concentration of low-density lipoprotein (LDL) bound cholesterol in blood by cholesterol deposits and by early coronary artery disease. The LDL apheresis technique has been introduced with the goal of reducing LDL cholesterol levels, thereby preventing the development of atherosclerosis. The literature on LDL apheresis reports 2 different facets, the therapeutic aspect associated with the lessening of LDL concentration and the initiation of a peroxidation process associated with the biocompatibility of the artificial membrane. Lipid and protein peroxidation gives rise to toxic and atherogenic hydroperoxide, mostly lipid hydroperoxides, and derivative compounds, which may offset the benefit of the procedure. In this paper, plasma hydroperoxide levels are determined along with the elevation of the serum and LDL antioxidant status in hypercholesterolemic patients before and following repeated LDL apheresis sessions. Hydroperoxide concentration has been expressed both in terms of plasma volume and LDL concentration. A highly significant increase in LDL lipid hydroperoxides is demonstrated when expressed in terms of LDL concentration and is associated with the LDL apheresis procedure. The usefulness of antioxidant supplementation in LDL apheresis is discussed.     

Long-term effects of LDL apheresis in patients with severe hypercholesterolemia

Familial hypercholesterolemia (FH) is an inherited disorder of lipoprotein metabolism involving mutations in the LDL receptor (LDL-R). Patients with mutation in one (heterozygous) or both (homozygous) genes have markedly elevated LDL cholesterol and are at increased risk for coronary heart disease (CHD). Aggressive lipid lowering is required for homozygous and many heterozygous FH patients. This often involves LDL-apheresis, where LDL and other apo-B containing lipoproteins are selectively removed from the plasma. We have retrospectively studied 34 patients treated with biweekly LDL-apheresis at the Hospital of the University of Pennsylvania. In our patient population, adverse events were uncommon and rarely resulted in shortened treatment time. There was a dramatic decrease in the relative risk of cardiovascular events and cardiovascular interventions in patients treated with LDL-apheresis for an average of 2.5 years. Some but not all patients had long-term reduction in their LDL levels as a result of LDL-apheresis, suggesting that time-averaged reduction in LDL and/or LDL:HDL ratios were responsible for clinical improvement. These data support the use of LDL-apheresis in patients with FH, as well as medication-intolerant patients that have elevated LDL cholesterol despite maximal pharmacological treatment.     

Beneficial effect of aggressive low-density lipoprotein apheresis in a familial hypercholesterolemic patient with severe diabetic scleredema.

We present a 59-year-old woman with severe diabetic scleredema (DS) associated with heterozygous familial hypercholesterolemia (FH). She had been treated with drugs to lower blood glucose, with insulin for diabetes mellitus (DM), and with low-density lipoprotein (LDL) apheresis therapy monthly or every 2 weeks in addition to drugs to lower serum lipids for FH. However, her scleredema had not improved. After we had tried weekly LDL apheresis therapy for a period of 3 years to treat her hyperlipidemia, the levels of her serum lipids were reduced to normal ranges, and scleredema in her nape improved. We also demonstrated the histopathological improvement in dermis of her cervical skin. We conclude that weekly LDL apheresis therapy is effective for diabetic scleredema that is resistant to conventional treatments.     

Genetic and biochemical analyses in dyslipidemic patients undergoing LDL apheresis

Objective : Familial hypercholesterolemia (FH) can be due to mutations in LDLR, PCSK9, and APOB. In phenotypically defined patients, a subset remains unresponsive to lipid‐lowering therapies and requires low density‐lipoprotein (LDL) apheresis treatment. In this pilot study, we examined the genotype/phenotype relationship in patients with dyslipidemia undergoing routine LDL apheresis. Design : LDLR, APOB, and PCKS9 were analyzed for disease‐causing mutations in seven patients undergoing routine LDL apheresis. Plasma and serum specimens were collected pre‐ and post‐apheresis and analyzed for lipid concentrations, Lp(a) cholesterol, and lipoprotein particle concentrations (via NMR). Results : We found that four patients harbored LDLR mutations and of these, three presented with xanthomas. While similar reductions in LDL‐cholesterol (LDL‐C), apolipoprotein B, and LDL particles (LDL‐P) were observed following apheresis in all patients, lipid profile analysis revealed the LDLR mutation‐positive cohort had a more pro‐atherogenic profile (higher LDL‐C, apolipoprotein B, LDL‐P, and small LDL‐P) pre‐apheresis. Conclusion : Our data show that not all clinically diagnosed FH patients who require routine apheresis have genetically defined disease. In our small cohort, those with LDLR mutations had a more proatherogenic phenotype than those without identifiable mutations. This pilot cohort suggests that patients receiving the maximum lipid lowering therapy could be further stratified, based on genetic make‐up, to optimize treatment. J. Clin. Apheresis 29:256–265, 2014. © 2014 Wiley Periodicals, Inc.     

经颈静脉肝内门腔静脉分流术患者的护理

目的 探讨经颈静脉肝内门腔静脉分流术的观察和护理效果.方法 2010年7月至2011年1月对因肝硬化失代偿期食管胃底静脉曲张破裂出血而入院的4例患者施行了经颈静脉肝内门腔静脉分流术(11Ps),并进行有针对性的护理.结果 4例患者TIPs术均成功,成功率100%,3例患者术后病情得到控制,护理效果满意,无并发症的发生,好转出院;1例因凝血功能差,腹腔出血,经止血、输血等抢救失败于术后7 h死亡.结论 做好术前准备及心理护理,术中密切观察患者生命体征,术后严格按医嘱用药,做好出院指导,可有效防止并发症,提高治疗效果.     

Single LDL apheresis improves serum remnant-like particle-cholesterol,C-reactive protein,and malondialdehyde-modified-low-density lipoprotein concentrations in Japanese hypercholesterolemic subjects

BACKGROUND: We examined a technique for detecting point mutations of K-ras codon 12 in stool samples using one-step polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) analysis, in order to determine whether it could be used to screen for colorectal cancer. METHODS: DNA was extracted from 200-mg stool specimens of 5 healthy controls and 31 colorectal cancer patients. A 107-base-pair fragment of exon 1 of K-ras was amplified by PCR using mismatched primers. PCR products were digested with Bst NI and analyzed by gel electrophoresis followed by silver staining. Specificity of one-step PCR/RFLP was examined by using synthetic oligonucleotides. The detection limit of K-ras codon 12 mutations was determined by using SW480 and HT29 cells. RESULTS: The K-ras gene was successfully amplified from all healthy controls and colorectal cancer patients studied. Mutations of K-ras codon 12 were not detected in any of the healthy controls, but were identified in 13 (41.9%) of the 31 patients with colorectal cancer. Mutations were detectable in all six synthetic mutant DNAs, while none were detected among the wild type. The detection limit of this method was > or = 0.1%. CONCLUSIONS: PCR/RFLP analysis could be used in mass screening for colorectal cancer, because it is highly specific, has a low detection limit, and is simpler than conventional methods for detecting genetic abnormalities.     

Changes in Iipoprotein(a), LDL-cholesterol and apolipoprotein B in homozygous familial hypercholesterolaemic patients treated with dextran sulfate LDL-apheresis

Abstract. We evaluated the effect of periodical treatment with LDL-apheresis by adsorption to dextran sulfate (Liposorber LA-15) on several aspects related to LDL and Lipoprotein(a) metabolisms, in three homozygous familial hypercholesterolaemic patients with LDL receptor deficiency. The dextran sulfate columns retained apolipoprotein B-containing particles with high affinity and capacity, in such a way that the treatment of a volume of plasma equivalent to three times the patient plasma volume resulted in an 85% decrease of circulating LDL-cholesterol and Lipoprotein(a). The continuous treatment with LDL-apheresis was highly beneficial for these patients since an average plasma concentration lower than 200 mg dl-′ for LDL-cholesterol, and lower than 25 mg dl^-′ for Lipoprotein(a) could be achieved by treating the patients once a week. After each apheresis treatment, plasma concentrations of these metabolites progressively returned to the pretreatment, steady-state, levels. The analysis of the rates of return allowed us to estimate the fractional catabolic rates. FCRs of LDL-cholesterol were 0–052, 0.049 and 0.047 pools day^-1, and those of apolipoprotein B, 0.065, 0.045 and 0.050 pools day^-1 in the three subjects, respectively. These values are much lower than those in normolipidaemic individuals as observed by others, and are in accordance with the LDL-receptor deficiency condition of our patients. Two of them had highly elevated Lipo-protein(a) plasma concentrations, and their FCRs of Lipoprotein(a) were calculated to be 0.112 and 0.066 pools day^-1. These values were significantly higher than the respective FCR of LDL-cholesterol and apolipoprotein B, which demonstrates that Lipopro-tein(a) and LDL were not metabolically homogeneous in these patients. Values of -kt for Lipoprotein(a), LDL-cholesterol and apolipoprotein B correlated during the first days inmediately after each apheresis session, suggesting that production of Lipoprotein(a) in these individuals was associated to that of apolipoprotein B. It is proposed that elevated Lipoprotein(a) plasma levels in familial hypercholesterolaemia are mainly a consequence of a high production rate rather than decreased fractional catabolic rate.     

Characterization of hepatic low density lipoprotein binding and cholesterol metabolism in normal and homozygous familial hypercholesterolemic subjects.

Patients with familial hypercholesterolemia have elevated levels of plasma low density lipoproteins (LDL), increased hepatic synthesis of apolipoprotein B-containing lipoproteins, defective binding of low density lipoproteins to fibroblasts, and premature atherosclerosis. The role of a hepatic low density lipoprotein receptor in normal man and its importance in the pathogenesis of familial hypercholesterolemia have not been previously determined. In the present study, direct comparison was made of the binding of LDL to hepatic membranes from normal and receptor-negative homozygous familial hypercholesterolemic subjects. The effects of calcium, EDTA, and temperature on the binding of lipoproteins to the hepatic membranes were also evaluated. At 4 degrees C, no significant difference in specific binding of LDL to hepatic membranes from normal and familial hypercholesterolemic subjects was observed. At 37 degrees C, both total and specific binding of LDL were significantly reduced in patients with familial hypercholesterolemia. Hepatic membrane binding of LDL from the two patients homozygous for receptor-negative familial hypercholesterolemia was 53 and 59% of normal. The activity of the rate-limiting enzyme in cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl coenzyme A reductase was normal; however, the total hepatic cholesterol and cholesteryl ester content was significantly increased from 53 to 129%. These results indicate that patients with familial hypercholesterolemia have a defect in the interaction of hepatic membranes with low density lipoproteins. This defect may lead to accelerated atherosclerosis by decreasing the cellular catabolism of LDL and enhancing the production of LDL, which is characteristic of patients homozygous for familial hypercholesterolemia.     

Improvement of endothelium-dependent coronary vasodilation after a single LDL apheresis in patients with hypercholesterolemia

The purpose of this study was to determine whether a single LDL apheresis would improve impaired endothelium-dependent dilation of the coronary artery in patients with hypercholesterolemia. Hypercholesterolemia is associated with impaired endothelial function, and human studies using cholesterol-lowering drugs indicate that endothelial function in the coronary arteries improves with reduction of serum LDL cholesterol over 6 to 12 months. The internal diameter of the left coronary artery and the coronary blood flow were measured by intracoronary Doppler-wire measurement and quantitative angiography before and immediately after a single LDL apheresis in a population of 15 patients with familial hypercholesterolemia. Endothelium-dependent vasodilation was assessed by intracoronary infusion of acetylcholine (1, 10, and 50 microg/min), and endothelium-independent vasodilation was assessed by intracoronary bolus infusion of isosorbide dinitrate (2.5 mg) or papaverine (10 mg). A single 3-hour LDL apheresis reduced serum LDL cholesterol by an average of 86.6 +/- 1.7%. After the LDL apheresis, the changes in the coronary artery diameter and coronary blood flow in response to an infusion of 50 microg/min of acetylcholine increased significantly compared to the pre-apheresis values (from -19.7 +/- 4.8 to -2.9 +/- 3.0% [P < 0.01] and from 80.7 +/- 27.6 to 155.3 +/- 23.5% [P < 0.01], respectively). The LDL apheresis did not significantly change the response of either parameter to infusion with isosorbide dinitrate or papaverine. The endothelial function of the epicardial coronary artery and the coronary microvasculature improved in hypercholesterolemic patients after only a single LDL apheresis, a procedure that markedly reduces the serum level of LDL cholesterol.     

Low-density lipoproteins in patients homozygous for familial hyperbetalipoproteinaemia.

1. The low-density lipoproteins (LDL; density 1-007-1-063 g/ml) from two patients homozygous for familial hyperbetalipoproteinaemia have been submitted to chemical and physicochemical analysis. 2. The presence of an anomalous lipoprotein with a low proportion of triglyceride and a raised proportion of cholesterol has been confirmed. 3. In one patient, this lipoprotein accounted for about 85% of the LDL, but in the second, the amount varied from about 85% to a point at which it could not be detected among the coexisting normal lipoproteins. 4. The protein moiety of this anomalous LDL has effectively the same amino acid composition as that derived from the LDL of healthy subjects. 5. The proportions of carbohydrate, phospholipid and fatty acids could not be reliably distinguished from those of normal LDL. 6. The molecular weight and diffusion constant of the abnormal lipoprotein, even in the purest preparation, were close to the values determined for normal LDL of similar flotation rate.     

Increased sensitivity of gastric acid secretion to gastrin in cirrhotic patients with portacaval shunt.

We studied acid secretory responses to exogenous pentagastrin and to exogenous and endogenous gastrin in 12 stable cirrhotic subjects with portacaval shunt, 12 unshunted cirrhotics, and 12 normal subjects. Basal and stimulated serum gastrin concentrations as well as basal and maximum acid outputs were similar in the three groups. At low doses of either exogenous pentagastrin or gastrin-17 (G17), cirrhotics with portacaval shunt secreted significantly greater amounts of gastric acid than unshunted subjects. After low doses of intragastric peptone, cirrhotics with portacaval shunt secreted significantly more acid than unshunted cirrhotics and normal subjects. At each measured serum gastrin concentration after either exogenous G17 or intragastric peptone meals, cirrhotics with portacaval shunt secreted more acid than the unshunted control groups and their dose-response curve was significantly shifted to the left. Thus, in cirrhotic patients with portacaval shunt, gastric acid secretion is abnormally sensitive to both exogenously administered or endogenously released gastrin.     

Impact of lipoprotein apheresis with dextran‐sulfate adsorption on the expression of genes involved in cardiovascular health in the blood of patients with homozygous familial hypercholesterolemia

Lipoprotein apheresis (LA) with dextran sulfate adsorption (DSA) is a reliable method to decrease LDL‐cholesterol (C) concentrations in patients with homozygous familial hypercholesterolemia (HoFH). The objective of the present study was to investigate the impact of LA with DSA on the mRNA expression of genes associated with cardiovascular health in the whole blood of HoFH patients. Blood samples were collected before and after LA treatment with DSA in 9 HoFH patients. Microarray analyses were performed to measure the whole blood expression of >30 000 annotated genes pre‐ and post‐LA. Concomitant reductions in LDL‐C (median ?73.8%, range: ?55.9 to ?82.0, P = .0001) and lipoprotein (a) concentrations (median ?74.1%, range ?65.6 to ?84.1, P = .003) were induced with LA treatment. LA with DSA did not impact the whole blood mRNA expression of most key genes involved in cardiovascular health, including those associated with cholesterol, fatty acid and lipoprotein metabolism. However, LA with DSA significantly upregulated the whole blood expression of early growth response protein (EGR)1 (1.94‐fold, P = .02), EGR3 (1.56‐fold, P = .0008) and B‐cell lymphoma 3‐encoded protein (BCL3; 1.25‐fold, P = .03). In conclusion, this study demonstrated that a single LA treatment with DSA has very limited impact on the whole blood expression of a broad spectrum of genes associated with cardiovascular health. Our results suggest that contact between blood cells and the primary membrane or extracorporeal circulation could upregulate the expression of EGR1, EGR3, BCL3, and MMP9 in blood cells.     

Characterization of a novel cellular defect in patients with phenotypic homozygous familial hypercholesterolemia

Familial hypercholesterolemia (FH) is characterized by a raised concentration of LDL in plasma that results in a significantly increased risk of premature atherosclerosis. In FH, impaired removal of LDL from the circulation results from inherited mutations in the LDL receptor gene or, more rarely, in the gene for apo B, the ligand for the LDL receptor. We have identified two unrelated clinically homozygous FH patients whose cells exhibit no measurable degradation of LDL in culture. Extensive analysis of DNA and mRNA revealed no defect in the LDL receptor, and alleles of the LDL receptor or apo B genes do not cosegregate with hypercholesterolemia in these families. FACS((R)) analysis of binding and uptake of fluorescent LDL or anti-LDL receptor antibodies showed that LDL receptors are on the cell surface and bind LDL normally, but fail to be internalized, suggesting that some component of endocytosis through clathrin-coated pits is defective. Internalization of the transferrin receptor occurs normally, suggesting that the defective gene product may interact specifically with the LDL receptor internalization signal. Identification of the defective gene will aid genetic diagnosis of other hypercholesterolemic patients and elucidate the mechanism by which LDL receptors are internalized.