Clinical profile, genetic spectrum and therapy evaluation of 19 Chinese pediatric patients with lipoprotein lipase deficiency.

BACKGROUND: Lipoprotein lipase (LPL) deficiency, the most common familial chylomicronemia syndrome (FCS), is a rare autosomal recessive disease characterized by chylomicronemia and severe hypertriglyceridemia (HTG), with limited clinical and genetic characterization. OBJECTIVE: To describe the manifestations and management of 19 pediatric patients with LPL-FCS. METHODS: LPL-FCS patients from 2014 to 2022 were divided into low-fat (LF), very-low-fat (VLF) and medium-chain-triglyceride (MCT) groups. Their clinical data were evaluated to investigate the effect of different diets. The genotype-phenotype relationship was assessed. Linear regression comparing long-chain triglyceride (LCT) intake and TG levels was analyzed. RESULTS: Nine novel LPL variants were identified in 19 LPL-FCS pediatric patients. At baseline, eruptive xanthomas occurred in 3/19 patients, acute pancreatitis in 2/19, splenomegaly in 6/19 and hepatomegaly in 3/19. The median triglyceride (TG) level (30.3 mmol/L) was markedly increased. The MCT group and VLF group with LCT intakes <20 en% (energy percentage) had considerably lower TG levels than the LF group (both p<0.05). The LF group presented with severe HTG and significantly decreased TG levels after restricting LCT intakes to <20 en% (p<0.05). Six infants decreased TG levels to <10 mmol/L by keeping LCT intake <10 en%. TG levels and LCT intake were positively correlated in both patients under 2 years (r=0.84) and those aged 2-9 years (r=0.89). No genotype-phenotype relationship was observed. CONCLUSIONS: This study broadens the clinical and genetic spectra of LPL-FCS. The primary therapy for LPL-FCS pediatric patients is restricting dietary LCTs to <10 en% or <20 en% depending on different ages. MCTs potentially provide extra energy.

Prognosis of Patients With Familial Hypercholesterolemia After Acute Coronary Syndromes.

BACKGROUND: Patients with heterozygous familial hypercholesterolemia (FH) and coronary heart disease have high mortality rates. However, in an era of high-dose statin prescription after acute coronary syndrome (ACS), the risk of recurrent coronary and cardiovascular events associated with FH might be mitigated. We compared coronary event rates between patients with and without FH after ACS. METHODS: We studied 4534 patients with ACS enrolled in a multicenter, prospective cohort study in Switzerland between 2009 and 2013 who were individually screened for FH on the basis of clinical criteria according to 3 definitions: the American Heart Association definition, the Simon Broome definition, and the Dutch Lipid Clinic definition. We used Cox proportional models to assess the 1-year risk of first recurrent coronary events defined as coronary death or myocardial infarction and adjusted for age, sex, body mass index, smoking, hypertension, diabetes mellitus, existing cardiovascular disease, high-dose statin at discharge, attendance at cardiac rehabilitation, and the GRACE (Global Registry of Acute Coronary Events) risk score for severity of ACS. RESULTS: At the 1-year follow-up, 153 patients (3.4%) had died, including 104 (2.3%) of fatal myocardial infarction. A further 113 patients (2.5%) experienced nonfatal myocardial infarction. The prevalence of FH was 2.5% with the American Heart Association definition, 5.5% with the Simon Broome definition, and 1.6% with the Dutch Lipid Clinic definition. Compared with patients without FH, the risk of coronary event recurrence after ACS was similar in patients with FH in unadjusted analyses, although patients with FH were >10 years younger. However, after multivariable adjustment including age, the risk was greater in patients with FH than without, with an adjusted hazard ratio of 2.46 (95% confidence interval, 1.07-5.65; P=0.034) for the American Heart Association definition, 2.73 (95% confidence interval, 1.46-5.11; P=0.002) for the Simon Broome definition, and 3.53 (95% confidence interval, 1.26-9.94; P=0.017) for the Dutch Lipid Clinic definition. Depending on which clinical definition of FH was used, between 94.5% and 99.1% of patients with FH were discharged on statins and between 74.0% and 82.3% on high-dose statins. CONCLUSIONS: Patients with FH and ACS have a >2-fold adjusted risk of coronary event recurrence within the first year after discharge than patients without FH despite the widespread use of high-intensity statins.

Anti-sense oligonucleotide therapies for the treatment of hyperlipidaemia.

INTRODUCTION: Anti-sense oligonucleotide (ASO) therapies are a new development in clinical pharmacology offering greater specificity compared to small molecule inhibitors and the ability to target intracellular process' not susceptible to antibody-based therapies. AREAS COVERED: This article reviews the chemical biology of ASOs and related RNA therapeutics. It then reviews the data on their use to treat hyperlipidaemia. Data on mipomersen - an ASO to apolipoprotein B-100(apoB) licensed for treatment of homozygous familial hypercholesterolaemia (FH) is presented. Few effective therapies are available to reduce atehrogenic lipoprotein (a) levels. An ASO therapy to apolipoprotein(a) (ISIS Apo(a)Rx) specifically reduced lipoprotein (a) levels by up to 78%. Treatment options for patients with familial chylomicronaemia syndrome (lipoprotein lipase deficiency; LPLD) or lipodystrophies are highly limited and often inadequate. Volanesorsen, an ASO to apolipoprotein C-3, shows promise in the treatment of LPLD and severe hypertriglyceridaemia as it increases clearance of triglyceride-rich lipoproteins and can normalise triglycerides in these patients. EXPERT OPINION: The uptake of the novel ASO therapies is likely to be limited to selected niche groups or orphan diseases. These will include homozygous FH, severe heterozygous FH for mipomersen; LPLD deficiency and lipodystrophy syndromes for volanesorsen and treatment of patients with high elevated Lp(a) levels.

Molecular-genetic aspects of familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is the world's most abundant and the most common heritable disorder of lipid metabolism. The prevalence of the disease in general population is 1:500. Therefore the approximate number of FH patients all over the world is 14 million. From the genetic point of view the disease originates as a result of mutations in genes affecting the processing of LDL particles from circulation, resulting in an increase in LDL cholesterol and hence total cholesterol. These are mutations in genes encoding LDL receptor, apolipoprotein B, proprotein convertase subtilisin/kexin 9 and LDL receptor adaptor protein 1. Cholesterol depositing in tissues and blood vessels of individuals creates tendon xanthoma, xanthelesma and arcus lipoides cornae. Due to the increased deposition of cholesterol in blood vessels, atherosclerosis process is accelerated, what leads to a significantly higher risk of premature cardiovascular diseases. Therefore, early clinical diagnosis confirmed by the DNA analysis, and effective treatment are crucial to reduce the mortality and high risk of premature atherosclerotic complications.

Effect of alipogene tiparvovec (AAV1-LPL(S447X)) on postprandial chylomicron metabolism in lipoprotein lipase-deficient patients.

BACKGROUND: Lipoprotein lipase-deficient (LPLD) individuals display marked chylomicronemia and hypertriglyceridemia associated with increased pancreatitis risk. The aim of this study was to determine the effect of i.m. administration of an adeno-associated viral vector (AAV1) for expression of LPL(S447X) in muscle (alipogene tiparvovec, AAV1-LPL(S447X)) on postprandial chylomicron metabolism and on nonesterified fatty acid (NEFA) and glycerol metabolism in LPLD individuals. METHODOLOGY: In an open-label clinical trial (CT-AMT-011-02), LPLD subjects were administered alipogene tiparvovec at a dose of 1 × 10(12) genome copies per kilogram. Two weeks before and 14 wk after administration, chylomicron metabolism and plasma palmitate and glycerol appearance rates were determined after ingestion of a low-fat meal containing (3)H-palmitate, combined with (continuous) iv infusion of [U-(13)C]palmitate and [1,1,2,3,3-(2)H]glycerol. PRINCIPAL FINDINGS: After administration of alipogene tiparvovec, the triglyceride (TG) content of the chylomicron fraction and the chylomicron-TG/total plasma TG ratio were reduced throughout the postprandial period. The postprandial peak chylomicron (3)H level and chylomicron (3)H area under the curve were greatly reduced (by 79 and 93%, 6 and 24 h after the test meal, respectively). There were no significant changes in plasma NEFA and glycerol appearance rates. Plasma glucose, insulin, and C-peptide also did not change. CONCLUSIONS/SIGNIFICANCE: Intramuscular administration of alipogene tiparvovec resulted in a significant improvement of postprandial chylomicron metabolism in LPLD patients, without inducing large postprandial NEFA spillover.

Lomitapide.

Aegerion Pharmaceuticals is developing lomitapide, a small-molecule, microsomal triglyceride transfer protein (MTP) inhibitor, for the treatment of both familial and primary hypercholesterolemia. Oral, once-daily lomitapide will be targeted at patients resistant to HMG-CoA reductase inhibitors (statins) either due to abnormalities in liver function or to discontinuation because of muscle pain. An oral formulation of lomitapide is in phase III development for homozygous familial hypercholesterolemia (hyperlipoproteinemia type IIa) in the US, Canada, Italy, and South Africa. This review discusses the key development milestones and therapeutic trials of this drug.

[Therapeutic application of diacylglycerol oil for the metabolic syndrome].

Excess adiposity has been shown to play a crucial role in the development of the metabolic syndrome. Characteristics for dyslipidemia in the metabolic syndrome are elevated fasting and postprandial triglyceride (TG) and decreased high-density lipoprotein-cholesterol (HDL-C). Diacylglycerol(DAG) has been suggested to suppress postprandial hyperlipidemia and promote negative caloric balance by increasing energy expenditure, due to intestinal physiochemical dynamics that differ from triacylglycerol (TAG). Our study (Study 1) demonstrated that DAG suppressed postprandial increase in TG-rich lipoprotein, very low density lipoprotein (VLDL), and insulin as compared with TAG in young male individuals. Further, our another study using the apolipoprotein C-II deficient subject demonstrated that DAG suppressed postprandial increase in VLDL-cholesterol and remnant-like particle-cholesterol compared with TAG, suggesting that DAG suppress postprandial TG-rich lipoprotein independent of lipoprotein lipase. Study 1 also showed that DAG significantly increased plasma serotonin, which is mostly present in intestine and mediates thermogenesis, proposing a possible mechanism for a postprandial increase in energy expenditure by DAG. Our studies presented DAG-mediated amelioration in postprandial TG-rich lipoprotein, insulin, and energy metabolism, indicating the therapeutic application of DAG for the metabolic syndrome.

Alipogene tiparvovec, an adeno-associated virus encoding the Ser(447)X variant of the human lipoprotein lipase gene for the treatment of patients with lipoprotein lipase deficiency.

Amsterdam Molecular Therapeutics BV is developing alipogene tiparvovec (Glybera, AMT-011, AAV1-LPLS447X), a Ser(447)X variant of the human lipoprotein lipase (LPL) gene (LPLSer(447)X) in an adeno-associated virus vector, as a potential intramuscular gene therapy for the treatment of LPL deficiency. Familial LPL deficiency is a rare, autosomal-recessive disorder of lipoprotein metabolism that is characterized by severe hypertriglyceridemia with episodes of abdominal pain, acute pancreatitis and eruptive cutaneous xanthomatosis. The lack of functional LPL in patients with LPL deficiency causes an accumulation of triglyceride (TG)-rich lipoproteins in the plasma. The LPLSer(447)X variant is associated with decreased levels of plasma TGs and increased HDL cholesterol concentrations compared with wild-type LPL. Preclinical studies evaluating alipogene tiparvovec in a mouse model of LPL deficiency demonstrated a long-term, dose-dependent correction of the lipid abnormalities. The first clinical trials in patients with LPL deficiency appear promising, with a significant decrease in the levels of plasma TGs observed in the first 3 months following the administration of alipogene tiparvovec, and an increase in local LPL activity and protein levels observed after 6 months. In addition, a decrease in pancreatitis frequency was observed during a 3-year follow-up period. At the time of publication, a phase II/III trial in patients with LPL deficiency, being conducted to further support the submission of an MAA to the EMEA for alipogene tiparvovec, was ongoing. The compound is also under investigation for the treatment of type V hyperlipoproteinemia, Syndrome X and non-alcoholic steatohepatitis.

[A case of the long-term observation of Bürger-Grütz disease]. / Sluchai dlitel'nogo nabliudeniia bolezni Biurgera--Griuttsa.

The authors observed Bürger-Grütz disease (primary hyperchylomicronemia, painful recurrent xanthomatosis, hepatosplenomegaly, hyperglycemia) for 20 years in a 54-year-old female patient. The disease ran a benign course. No marked vascular lesions, progressive atherosclerosis, diabetes mellitus arose. This is an original report of Bürger-Grütz disease long-term course and life-long heparin treatment in this country.