scholarly journals Compound Heterozygous Familial Hypercholesterolemia and Familial Defective Apolipoprotein B-100 Produce Exaggerated Hypercholesterolemia

2001 ◽  
Vol 47 (3) ◽  
pp. 438-443 ◽  
Author(s):  
E Shyong Tai ◽  
Evelyn S C Koay ◽  
Edmund Chan ◽  
Tzer Jing Seng ◽  
Lih Ming Loh ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Genetic Analysis ◽  
Familial Hypercholesterolemia ◽  
Apolipoprotein B ◽  
Ldl Cholesterol ◽  
Index Case ◽  
Ldl Receptor ◽  
Cholesterol Concentration ◽  
Apo B ◽  
First Degree Relatives

Abstract Background: Familial hypercholesterolemia (FH) and familial defective apolipoprotein B-100 (FDB) represent ligand-receptor disorders that are complementary. Individuals with both FH and FDB are unusual. We report a family with both disorders and the impact of the mutations on the phenotypes of the family members. Methods: We used single strand conformation polymorphism (SSCP) and denaturing gradient gel electrophoresis (DGGE) for genetic analysis of all 18 exons and the promoter region of the LDL receptor and DGGE for genetic analysis of the apolipoprotein B-100 (apo B-100) gene. The functional significance of the apo B-100 mutation was studied using a U937 cell proliferation assay. Fasting serum lipid profiles were determined for the index case and seven first-degree relatives. Results: One of the patient’s sisters had a missense mutation (Asp407→Lys) in exon 9 of the LDL receptor and a serum LDL-cholesterol concentration of 4.07 mmol/L. Four other first-degree relatives had hyperlipidemia but no LDL-receptor mutation. However, these subjects had a mutation of the apo B-100 gene (Arg3500→Trp). The cell proliferation rate of U937 cells fed with LDL from other subjects with the same mutation was fourfold less than that of controls. The index case had both FH- and FDB-related mutations. Her serum LDL-cholesterol (9.47 mmol/L) was higher than all other relatives tested. Conclusions: Existence of both FH and FDB should be considered in families with LDL-receptor mutations in some but not all individuals with hypercholesterolemia or when some individuals in families with FH exhibit exaggerated hypercholesterolemia.

Screening for familial defective apolipoprotein B-100 with improved U937 monocyte proliferation assay

1994 ◽  
Vol 40 (3) ◽  
pp. 395-399 ◽  
Author(s):  
A J Van den Broek ◽  
L Hollaar ◽  
H I Schaefer ◽  
A Van der Laarse ◽  
H Schuster ◽  
...  
Keyword(s):  
Apolipoprotein B ◽  
Ldl Cholesterol ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Human Monocyte ◽  
Cell Number ◽  
Cholesterol Concentration ◽  
U937 Cells ◽  
Proliferation Assay ◽  
Apo B

Abstract Frostegård et al. (J Lipid Res 1990;31:37-44) demonstrated that the proliferation of the human monocyte cell line U937 is critically dependent on the uptake of low-density lipoprotein (LDL) via the apo B, E (LDL) receptor, a characteristic that was used to detect patients with familial defective apolipoprotein B-100 (FDB). Here we applied this principle to develop a simple and reproducible assay for the detection of patients with functionally defective LDL. We added serum to U937 cells in cholesterol-free incubation medium and determined the increase in cell number after a 72-h incubation at 37 degrees C by using an electronic cell counter. Sera from 10 normolipidemic individuals and from 34 patients with type IIa hyperlipoproteinemia stimulated the growth of U937 cells in proportion to the exogenous cholesterol concentration (r = 0.83, P < 0.001) and the LDL-cholesterol concentration (r = 0.81, P < 0.001). However, sera from 16 patients with FDB stimulated less cell proliferation than did sera from patients with type IIa hyperlipoproteinemia with equal LDL-cholesterol concentrations. With a 15% reduction in growth as the cutoff value, this test had a sensitivity and specificity for diagnosis of FDB of 87.5% and 100%, respectively. The improved U937 monocyte proliferation assay can be used for screening hypercholesterolemic patients to detect individuals with functionally defective LDL.

scholarly journals Characterization of Atherosclerosis Formation in a Murine Model of Type IIa Human Familial Hypercholesterolemia

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Chiharu Miyajima ◽  
Takayuki Iwaki ◽  
Kazuo Umemura ◽  
Victoria A. Ploplis ◽  
Francis J. Castellino
Keyword(s):  
Familial Hypercholesterolemia ◽  
Apolipoprotein B ◽  
Ldl Cholesterol ◽  
Genetic Model ◽  
Ldl Receptor ◽  
Normal Diet ◽  
Atherosclerotic Plaques ◽  
Key Features ◽  
Very High

A murine genetic model of LDL-cholesterol- (LDL-C-) driven atherosclerosis, based on complete deficiencies of both the LDL-receptor (Ldlr-/-) and key catalytic component of an apolipoprotein B-edisome complex (Apobec1-/-), which converts apoB-100 to apoB-48, has been extensively characterized. These gene deficiencies allow high levels of apoB-100 to be present and inefficiently cleared, thus leading to very high levels of LDL-C in mice on a normal diet. Many key features of atherosclerotic plaques observed in human familial hypercholesterolemia are found in these mice as they are allowed to age through 72 weeks. The general characteristics include the presence of high levels of LDL-C in plasma and macrophage-related fatty streak formation in the aortic tree, which progressively worsens with age. More specifically, plaque found in the aortic sinuses contains a lipid core with relatively high numbers of macrophages and a smooth muscle cell α-actin- and collagen-containing cap, which thins with age. These critical features of plaque progression suggest that the Ldlr-/-/Apobec1-/- mouse line presents a superior model of LDL-C-driven atherosclerosis.

Cholesterol determination in serum after fractionation of lipoproteins by immunoprecipitation.

1985 ◽  
Vol 31 (2) ◽  
pp. 252-256 ◽  
Author(s):  
C C Heuck ◽  
I Erbe ◽  
D Mathias
Keyword(s):  
Apolipoprotein B ◽  
Ldl Cholesterol ◽  
Phosphotungstic Acid ◽  
Cholesterol Concentration ◽  
Apo B ◽  
Cholesterol Determination ◽  
Apo Ai

Abstract We investigated the immunoprecipitation of apolipoprotein B-binding lipoproteins, or of apo A-I- and apo C-binding lipoproteins, by delipidated antiserum for measuring cholesterol in the nonprecipitated lipoprotein fractions. After immunoprecipitation of serum with delipidated anti-apo B, we determined by immunoelectrophoresis that no beta- or pre-beta lipoproteins were present, whereas alpha-lipoproteins remained in the supernate. Conversely, after immunoprecipitation with an antiserum against apo A-I + apo C, only lipoproteins with beta-mobility were detected and no apo B from beta-lipoproteins was in the precipitate. The concentration of cholesterol in the supernate after immunoprecipitation with anti-apo B correlated highly (r = 0.93, n = 118) with cholesterol measured after precipitation with phosphotungstic acid/MgCl2. The cholesterol concentration after immunoprecipitation with anti-apo AI and anti-apo C correlated similarly well (r = 0.94, n = 145) with the LDL-cholesterol calculated by Friedewald's formula in serum specimens reflecting moderate hyperlipoproteinemia.

scholarly journals Fasting Is Not Routinely Required for Determination of a Lipid Profile: Clinical and Laboratory Implications Including Flagging at Desirable Concentration Cutpoints—A Joint Consensus Statement from the European Atherosclerosis Society and European Federation of Clinical Chemistry and Laboratory Medicine

2016 ◽  
Vol 62 (7) ◽  
pp. 930-946 ◽  
Author(s):  
Børge G Nordestgaard ◽  
Anne Langsted ◽  
Samia Mora ◽  
Genovefa Kolovou ◽  
Hannsjörg Baum ◽  
...  
Keyword(s):  
Total Cholesterol ◽  
Familial Hypercholesterolemia ◽  
Apolipoprotein B ◽  
Ldl Cholesterol ◽  
Clinical Chemistry ◽  
Hdl Cholesterol ◽  
Lipid Profiles ◽  
Apolipoprotein A1 ◽  
Lipoprotein A ◽  
Remnant Cholesterol

Abstract AIMS To critically evaluate the clinical implications of the use of non-fasting rather than fasting lipid profiles and to provide guidance for the laboratory reporting of abnormal non-fasting or fasting lipid profiles. METHODS AND RESULTS Extensive observational data, in which random non-fasting lipid profiles have been compared with those determined under fasting conditions, indicate that the maximal mean changes at 1–6 h after habitual meals are not clinically significant [+0.3 mmol/L (26 mg/dL) for triglycerides; −0.2 mmol/L (8 mg/dL) for total cholesterol; −0.2 mmol/L (8 mg/dL) for LDL cholesterol; +0.2 mmol/L (8 mg/dL) for calculated remnant cholesterol; −0.2 mmol/L (8 mg/dL) for calculated non-HDL cholesterol]; concentrations of HDL cholesterol, apolipoprotein A1, apolipoprotein B, and lipoprotein(a) are not affected by fasting/non-fasting status. In addition, non-fasting and fasting concentrations vary similarly over time and are comparable in the prediction of cardiovascular disease. To improve patient compliance with lipid testing, we therefore recommend the routine use of non-fasting lipid profiles, whereas fasting sampling may be considered when non-fasting triglycerides are >5 mmol/L (440 mg/dL). For non-fasting samples, laboratory reports should flag abnormal concentrations as triglycerides ≥2 mmol/L (175 mg/dL), total cholesterol ≥5 mmol/L (190 mg/dL), LDL cholesterol ≥3 mmol/L (115 mg/dL), calculated remnant cholesterol ≥0.9 mmol/L (35 mg/dL), calculated non-HDL cholesterol ≥3.9 mmol/L (150 mg/dL), HDL cholesterol ≤1 mmol/L (40 mg/dL), apolipoprotein A1 ≤1.25 g/L (125 mg/dL), apolipoprotein B ≥1.0 g/L (100 mg/dL), and lipoprotein(a) ≥50 mg/dL (80th percentile); for fasting samples, abnormal concentrations correspond to triglycerides ≥1.7 mmol/L (150 mg/dL). Life-threatening concentrations require separate referral for the risk of pancreatitis when triglycerides are >10 mmol/L (880 mg/dL), for homozygous familial hypercholesterolemia when LDL cholesterol is >13 mmol/L (500 mg/dL), for heterozygous familial hypercholesterolemia when LDL cholesterol is >5 mmol/L (190 mg/dL), and for very high cardiovascular risk when lipoprotein(a) >150 mg/dL (99th percentile). CONCLUSIONS We recommend that non-fasting blood samples be routinely used for the assessment of plasma lipid profiles. Laboratory reports should flag abnormal values on the basis of desirable concentration cutpoints. Non-fasting and fasting measurements should be complementary but not mutually exclusive.

scholarly journals Lipoprotein Signatures of Cholesteryl Ester Transfer Protein and HMG-CoA Reductase Inhibition

2018 ◽  
Author(s):  
Johannes Kettunen ◽  
Michael V. Holmes ◽  
Elias Allara ◽  
Olga Anufrieva ◽  
Pauli Ohukainen ◽  
...  
Keyword(s):  
Apolipoprotein B ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Triglyceride Composition ◽  
Cholesterol Concentration ◽  
Resonance Spectroscopy ◽  
Low Density ◽  
Triglyceride Content ◽  
Cetp Inhibition

AbstractBackgroundCETP inhibition reduces vascular event rates but confusion surrounds its low-density lipoprotein (LDL)-cholesterol effects. We sought to clarify associations of genetic inhibition of CETP on detailed lipoproteins.Methods and ResultsWe used variants associated withCETP(rs247617) andHMGCR(rs12916) expression in 62,400 Europeans with detailed lipoprotein profiling from nuclear magnetic resonance spectroscopy. Genetic associations were scaled to 10% lower risk of coronary heart disease (CHD). Associations of lipoprotein measures with risk of incident CHD in three population-based cohorts (770 cases) were examined.CETPandHMGCRhad near-identical associations with LDL-cholesterol concentration estimated by Friedewald-equation.HMGCRhad a relatively consistent effect on cholesterol concentrations across all apolipoprotein B-containing lipoproteins.CETPhad stronger effects on remnant and very-low-density lipoprotein cholesterol but no effect on cholesterol concentrations in LDL defined by particle size (diameter 18–26 nm) (-0.02SD 95%CI: -0.10, 0.05 forCETPversus -0.24SD, 95%CI -0.30, -0.18 forHMGCR).CETPhad profound effects on lipid compositions of lipoproteins, with strong reductions in the triglyceride content of all highdensity lipoprotein (HDL) particles. These alterations in triglyceride composition within HDL subclasses were observationally associated with risk of CHD, independently of total cholesterol and triglycerides (strongest HR per 1-SD higher triglyceride composition in very-large HDL 1.35; 95%CI: 1.18, 1.54).ConclusionCETP inhibition does not affect size-specific LDL cholesterol but may lower CHD risk by lowering cholesterol in other apolipoprotein-B containing lipoproteins and lowering triglyceride content of HDL particles. Conventional composite lipid assays may mask heterogeneous effects of lipid-altering therapies.

scholarly journals Familial Hypercholesterolemia: Three “under” (Understood, Underdiagnosed, and Undertreated) Disease

2021 ◽  
Author(s):  
Vladimir O. Konstantinov
Keyword(s):  
Familial Hypercholesterolemia ◽  
Time Course ◽  
Ldl Cholesterol ◽  
Genetic Disorders ◽  
Receptor Gene ◽  
Ldl Receptor ◽  
Hdl Cholesterol ◽  
Blood Cholesterol ◽  
Healthy Population ◽  
Loss Of Function

Familial hypercholesterolemia (FH) is one of the most prevalent genetic disorders leading to premature atherosclerosis and coronary heart disease. The main cause of FH is a mutation in the LDL-receptor gene that leads to loss of function of these receptors causing high levels of blood cholesterol. The diagnosis of FH is not very easy. Wide screenings are needed to reveal high levels of LDL cholesterol among “healthy” population. If the patient has MI or stroke at an early age, high levels of LDL cholesterol, and tendon xanthomas, the diagnosis of FH becomes much more clear. Genetic testing is a gold standard in the diagnosis of FH. There are several factors, influencing the time course of FH. Smoking males with low levels of HDL cholesterol have an extremely higher risk of death than nonsmoking females with high HDL cholesterol. Management of FH includes low cholesterol diet, statin and ezetimibe treatment, PCSK inhibitors, and LDL aphaeresis. Early and effective treatment influences much the prognosis in FH patients.

Abstract 50: A Phase I Clinical Trial Evaluating the Safety of With Allogeneic Adipose Tissue-derived Multilineage Progenitor Cells-transplantation Therapy in Homozygous Familial Hypercholesterolemia Patients

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Masahiro Koseki ◽  
Shizuya Yamashita
Keyword(s):  
Clinical Trial ◽  
Liver Transplantation ◽  
Adipose Tissue ◽  
Progenitor Cells ◽  
Familial Hypercholesterolemia ◽  
Ldl Cholesterol ◽  
Ldl Receptor ◽  
Ldl Apheresis ◽  
Definitive Therapy ◽  
Transplantation Therapy

Familial hypercholesterolemia (FH) is an inherited disorder, mainly caused by defects in low-density lipoprotein (LDL) receptor gene. The patients are characterized by high LDL cholesterol levels in the blood and premature cardiovascular disease. Although most of heterozygous FH patients are usually treated with statin, ezetimibe and bile acid sequestrants, homozygous FH patients are resistant to drug therapy. Therefore, in Japan, many of homozygous FH patients are treated by LDL-apheresis. LDL-apheresis is a great procedure to remove LDL cholesterol from the blood and contribute to improve prognosis of homozygous FH patients. However, the effect of removing LDL cholesterol is temporary and still not enough. As a definitive therapy, liver transplantation therapy could be one of options to recover LDL receptor, but donor is limited in Japan. Therefore, based on the increase of the evidence about the safety of mesenchymal stem cells and percutaneous transhepatic portal approach in islet transplantation, we have developed a cell transplantation therapy with allogeneic adipose tissue-derived multilineage progenitor cells (ADMPCs), as an alternative treatment instead of liver transplantation. Our group has already proved that xenogenic transplantation of human ADMPCs into Watanabe heritable hyperlipidemic rabbits resulted in significant reductions in total cholesterol, and the reductions were observed within 4 weeks and maintained for 12 weeks. These results suggested that hADMPC transplantation could correct the metabolic defects and be a novel therapy for inherited liver diseases. Here, we report a protocol for the first-in-human clinical trial, which has been approved by the institutional review board and Ministry of Health, Labour and Welfare, Japan.

scholarly journals Plasma Proprotein Convertase Subtilisin/Kexin Type 9: A Marker of LDL Apolipoprotein B-100 Catabolism?

2009 ◽  
Vol 55 (11) ◽  
pp. 2049-2052 ◽  
Author(s):  
Dick C Chan ◽  
Gilles Lambert ◽  
P Hugh R Barrett ◽  
Kerry-Anne Rye ◽  
Esther M M Ooi ◽  
...  
Keyword(s):  
Apolipoprotein B ◽  
Experimental Studies ◽  
Ldl Receptor ◽  
Model Assessment ◽  
Proprotein Convertase ◽  
Apo B ◽  
Catabolic Rate ◽  
Wide Range ◽  
Important Regulator ◽  
Kinetics Of

Abstract Background: Experimental studies suggest that proprotein convertase subtilisin/kexin type 9 (PCSK9) is an important regulator of LDL metabolism because of its ability to facilitate degradation of the LDL receptor. We investigated the association between plasma PCSK9 concentration and LDL apolipoprotein B-100 (apo B-100) metabolism in men with a wide range of body mass index values. Methods: We used GC-MS to study the kinetics of LDL apo B-100 after intravenous administration of deuterated leucine and analyzed the data by compartmental modeling. The plasma PCSK9 concentration was measured by ELISA. Results: Univariate regression analysis revealed the plasma PCSK9 concentration to be significantly and positively correlated with cholesterol (r = 0.543; P = 0.011), LDL cholesterol (r = 0.543; P = 0.011), apo B-100 (r = 0.548; P = 0.010), and LDL apo B-100 concentrations (r = 0.514; P = 0.023), and inversely correlated with the LDL apo B-100 fractional catabolic rate (FCR) (r = −0.456; P = 0.038). The association between plasma PCSK9 concentration and the LDL apo B-100 FCR remained statistically significant after adjusting for age, obesity, plasma insulin, homeostasis model assessment score, and dietary energy; however, this association had borderline significance after adjusting for plasma lathosterol. Conclusions: In men, variation in plasma PCSK9 concentration influences the catabolism of LDL apo B-100. This finding appears to be independent of obesity, insulin resistance, energy intake, and age.

Genetic polymorphism of the apolipoprotein B gene locus influences serum LDL cholesterol level in familial hypercholesterolemia

1989 ◽  
Vol 82 (4) ◽  
Author(s):  
Katriina Aalto-Set�l� ◽  
Helena Gylling ◽  
Eero Helve ◽  
Petri Kovanen ◽  
TatuA. Miettinen ◽  
...  
Keyword(s):  
Genetic Polymorphism ◽  
Familial Hypercholesterolemia ◽  
Cholesterol Level ◽  
Apolipoprotein B ◽  
Gene Locus ◽  
Ldl Cholesterol ◽  
Apolipoprotein B Gene

Comparison of methods for measurement of apolipoprotein B and cholesterol in low-density lipoproteins

1997 ◽  
Vol 43 (2) ◽  
pp. 390-393 ◽  
Author(s):  
Ljubica Vrga ◽  
Christine Contacos ◽  
Stephen C H Li ◽  
David R Sullivan
Keyword(s):  
Apolipoprotein B ◽  
Ldl Cholesterol ◽  
Low Density Lipoproteins ◽  
Plasma Triglyceride ◽  
Low Density ◽  
Comparison Of Methods ◽  
Apo B ◽  
Simple Alternative ◽  
Cholesterol Measurement ◽  
Commercial Kit

Abstract We describe a new method for the direct measurement of LDL-apolipoprotein (apo) B by using a commercial kit that isolates LDL by immunoseparation. We evaluated immunoseparation of LDL for apo B and cholesterol measurement in 46 dyslipidemic patients with LDL-cholesterol (LDL-C) between 1.5 and 8.2 mmol/L, 11 of whom had plasma triglyceride (TG) concentrations >4.0 mmol/L. There was a reasonable correlation (r = 0.94, n = 40) between LDL-apo B obtained after immunoseparation and d >1.006 kg/L apo B obtained after ultracentrifugation. LDL-C by the immunoseparation method also correlated well (r = 0.98, n = 46) with the d >1.006 kg/L cholesterol after ultracentrifugation. These results show that immunoseparation can be used to determine LDL-apo B, even in hypertriglyceridemic samples. This method may provide a quick and simple alternative for the identification of hyperapobetalipoproteinemia, even when TG concentrations are high.

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