Familial chylomicronemia syndrome: Bringing to life dietary recommendations throughout the life span

Recognition and management of persistent chylomicronemia: A joint expert clinical consensus by the National Lipid Association and the American Society for Preventive Cardiology

Extreme hypertriglyceridemia, defined as triglyceride (TG) levels ≥1000 mg/dL, is almost always indicative of chylomicronemia. The current diagnostic approach categorizes individuals with chylomicronemia into familial chylomicronemia syndrome (FCS; prevalence 1-10 per million), caused by the biallelic combination of pathogenic variants that impair the lipolytic action of lipoprotein lipase (LPL), or multifactorial chylomicronemia syndrome (MCS, 1 in 500). A pragmatic framework should emphasize the severity of the phenotype and the risk of complications. Therefore, we endorse the term "persistent chylomicronemia" defined as TG ≥1000 mg/dL in more than half of the measurements to encompass patients with the highest risk for pancreatitis, regardless of their genetic predisposition. We suggest classification of PC into four subtypes: 1) genetic FCS, 2) clinical FCS, 3) PC with "alarm" features, and 4) PC without alarm features. Although patients with FCS most likely have PC, the vast majority with PC do not have genetic FCS. Proposed alarm features are: (a) history of recurrent TG-induced acute pancreatitis, (b) recurrent hospitalizations for severe abdominal pain without another identified cause, (c) childhood pancreatitis, (d) family history of TG-induced pancreatitis, and/or (e) post-heparin LPL activity <20 % of normal value. Alarm features constitute the strongest risk factors for future acute pancreatitis risk. Patients with PC and alarm features have very high risk of pancreatitis, comparable to that in patients with FCS. Effective, innovative treatments for PC, like apoC-III inhibitors, have been developed. Combined with lifestyle modifications, these agents markedly lower TG levels and risk of pancreatitis in the very-high-risk groups, irrespective of the monogenic etiology. Pragmatic definitions, education, and focus on patients with PC specifically those with alarm features could help mitigate the risk of acute pancreatitis and other complications.

Futility of plasmapheresis, insulin in normoglycaemic individuals, or heparin in the treatment of hypertriglyceridaemia-induced acute pancreatitis

There is a well-established link between the severity of hypertriglyceridaemia and acute pancreatitis and long-term triglyceride-lowering therapies known to prevent episodes of acute pancreatitis. Therefore, it has been assumed, without firm evidence, that rapid lowering of plasma triglycerides would be an effective strategy for reducing the clinical severity of acute pancreatitis and improving health outcomes. Therapies, such as intravenous heparin, intravenous insulin in normoglycaemic individuals (with glucose to prevent hypoglycaemia), and plasmapheresis, continue to be widely used as therapeutic interventions to rapidly reduce serum triglyceride concentration. These therapies are all associated with a risk of adverse reactions, require increased resources, and increase health-care costs. Randomised controlled clinical trials of these therapies have generally shown more rapid reductions in plasma triglycerides than conventional supportive care with the patient made nil by mouth. However, these three therapies alone or in combination, have failed to show effectiveness in improving substantial health benefit outcome measures. While we recognise the theoretical basis for rapidly reducing plasma triglycerides in hypertriglyceridaemia-induced pancreatitis-based on our review of studies using heparin, insulin, plasmapheresis, or a combination of these-these strategies overall do not reduce complications associated with acute pancreatitis or the rapidity of disease resolution. Therefore, we do not advocate the use of triglyceride-lowering therapies at this time, pending more convincing evidence.

Novel Therapeutics for Familial Chylomicronemia Syndrome

PURPOSE OF REVIEW

This review discusses new treatment approaches for familial chylomicronemia syndrome (FCS), a rare disorder affecting triglyceride metabolism. The focus is on antisense oligonucleotides (ASO) and small-interfering RNA (siRNA) therapies targeting APOC3 and angiopoietin-like protein 3 (ANGPTL3).

RECENT FINDINGS

Volanesorsen, an ASO targeting APOC3, has shown effectiveness in managing FCS, multifactorial chylomicronemia, and familial partial lipodystrophy, but its use is limited by thrombocytopenia. Emerging therapies, Olezarsen (ASO anti-APOC3) and Plozasiran (siRNA anti-APOC3), both conjugated with GalNAc, show promise in reducing acute pancreatitis risk without platelet concerns. ANGPTL3 inhibition requires residual lipoprotein lipase (LPL) activity, with only siRNA-based therapies-zodasiran and solbinsiran-under investigation. Suppressing APOC3 expression and targeting ANGPTL3 via siRNA offer significant potential, but long-term studies are needed to confirm their efficacy and safety. Future research may explore gene-editing strategies using lipid nanoparticle-based CRISPR-Cas9 delivery for more durable treatment outcomes.

Olezarsen for the Treatment of Familial Chylomicronemia Syndrome

OBJECTIVE

This review aims to evaluate the efficacy and safety of olezarsen (Tryngolza) in treating familial chylomicronemia syndrome (FCS), a rare genetic disorder characterized by severe hypertriglyceridemia.

DATA SOURCES

A comprehensive literature search was conducted via PubMed from January 2022 to mid-March 2025, using keywords such as olezarsen, antisense oligonucleotide, triglyceride, hypertriglyceridemia, apolipoprotein C3 (APOC3), and cardiovascular.

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language studies assessing the pharmacokinetics, pharmacology, efficacy, or safety of olezarsen were included. Data from the US Food and Drug Administration (FDA)-approved package insert were also reviewed.

DATA SYNTHESIS

Olezarsen is an antisense oligonucleotide targeting APOC3 mRNA, a key regulator of plasma triglyceride levels. It has been shown to significantly reduce triglyceride levels via APOC3 protein degradation. Clinical trials have demonstrated substantial reductions in triglyceride levels and APOC3, with minimal adverse events. Phase 2 and 3 trials showed consistent efficacy and safety profiles, with common adverse events including COVID-19 infection, abdominal pain, and diarrhea.Relevance to Patient Care and Clinical Practice in Comparison to Existing Drugs:Olezarsen offers a targeted and effective treatment for FCS, addressing limitations of traditional therapies such as fibrates, omega-3 fatty acids, and statins. Its novel mechanism of action and once-monthly dosing regimen may improve patient adherence, providing significant advancement in FCS management.

CONCLUSION AND RELEVANCE

Olezarsen represents a new treatment for FCS, offering a targeted approach to significantly reduce triglyceride levels. Its integration into clinical practice has the potential to transform the management of FCS; however, more studies are needed to firmly establish its role.

Familial chylomicronemia syndrome and treatments to target hepatic APOC3 mRNA

Familial chylomicronemia syndrome (FCS) is a rare, recessive monogenic disorder characterized by severely elevated plasma triglyceride (TG) levels due to absent or markedly impaired lipoprotein lipase activity, leading to a greatly increased risk of acute pancreatitis. Naturally occurring very low levels of apoC-III are associated with low TG levels; thus, apoC-III is a target for TG lowering, and therapies have been developed to reduce apoC-III. Strategies to inhibit hepatic apoC-III synthesis include antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs). In the last decade, technologies have been developed to enhance hepatic delivery of these potential therapeutic agents by conjugation of the ligand triantennary N-acetyl galactosamine to ASO and siRNA for receptor-mediated uptake by hepatocytes, where apoC-III is predominantly expressed. Enhanced delivery of these pharmacological agents to the target tissue has been found to support lower and/or less frequent dosing with consequent lower total systemic exposure. One antisense agent, the ASO olezarsen, is now approved by the US Food and Drug Administration (FDA) as an adjunct to diet to lower triglycerides in adults with FCS, and the other, the siRNA plozasiran, is in late-stage clinical development. Both agents have shown effectiveness in reducing both apoC-III and TG levels across several study populations. Reduced TG, lower rates of acute pancreatitis events, and similar proportions of adverse events in placebo and treated patients were recently demonstrated in placebo-controlled phase 3 trials of patients with FCS treated with olezarsen in Balance and with plozasiran in PALISADE. This review discusses causes and consequences of FCS and the rationale and progress made in developing APOC3 RNA-targeted therapeutics for the treatment of FCS.

Fiber in the Treatment of Dyslipidemia in Pediatric Patients

Dietary fiber is present in many food categories (fruits, cereals, vegetables, legumes), and is considered a beneficial component of adult and children's diets. It is now well-established that dietary intervention is the first line of treatment for childhood dyslipidemia, both as a curative intervention (Familial Hyperchylomicronemia Syndrome, Sitosterolemia) and as an appropriate lifestyle aimed at improving the lipid profile in dyslipidemia, which is associated with early atherosclerosis and an increased risk of cardiovascular disease in adulthood (Familial Hypercholesterolemia, overweight- and obesity-related dyslipidemia). In this paper, we reviewed the main consensus documents to determine the current indications for its use in children and adolescents, and analyzed the few specific papers on the subject in the literature to assess how fiber is currently used in the treatment of pediatric dyslipidemia, what precautions should be taken, and what the main benefits of fiber are on the lipid profile and cardiovascular risk.

Recognition and management of persistent chylomicronemia: A joint expert clinical consensus by the National Lipid Association and the American Society for Preventive Cardiology

Extreme hypertriglyceridemia, defined as triglyceride (TG) levels ≥1000 mg/dL, is almost always indicative of chylomicronemia. The current diagnostic approach categorizes individuals with chylomicronemia into familial chylomicronemia syndrome (FCS; prevalence 1-10 per million), caused by the biallelic combination of pathogenic variants that impair the lipolytic action of lipoprotein lipase (LPL), or multifactorial chylomicronemia syndrome (MCS, 1 in 500). A pragmatic framework should emphasize the severity of the phenotype and the risk of complications. Therefore, we endorse the term "persistent chylomicronemia (PC)" defined as TG ≥1000 mg/dL in more than half of the measurements to encompass patients with the highest risk for pancreatitis, regardless of their genetic predisposition. We suggest classification of PC into 4 subtypes: (1) genetic FCS, (2) clinical FCS, (3) PC with "alarm" features, and (4) PC without alarm features. Although patients with FCS most likely have PC, the vast majority with PC do not have genetic FCS. Proposed alarm features are: (a) history of recurrent TG-induced acute pancreatitis, (b) recurrent hospitalizations for severe abdominal pain without another identified cause, (c) childhood pancreatitis, (d) family history of TG-induced pancreatitis, and/or (e) postheparin LPL activity <20% of normal value. Alarm features constitute the strongest risk factors for future acute pancreatitis risk. Patients with PC and alarm features have very high risk of pancreatitis, comparable to that in patients with FCS. Effective, innovative treatments for PC, like apolipoprotein C-III inhibitors, have been developed. Combined with lifestyle modifications, these agents markedly lower TG levels and risk of pancreatitis in the very-high-risk groups, irrespective of the monogenic etiology. Pragmatic definitions, education, and focus on patients with PC, specifically those with alarm features, could help mitigate the risk of acute pancreatitis and other complications.

Familial chylomicronemia syndrome: An expert clinical review from the National Lipid Association

Familial chylomicronemia syndrome (FCS) is a rare Mendelian autosomal recessive disorder (MIM 238600) characterized by extreme and sustained hypertriglyceridemia due to profound reduction of lipoprotein lipase (LPL) activity. This expert opinion statement synthesizes current knowledge on the definition, pathophysiology, genetics, prevalence, diagnosis, and management of FCS. FCS typically manifests at a young age with persistent severe hypertriglyceridemia-defined as ≥10 mmol/L (≥885 mg/dL), or ≥1000 mg/dL (≥11.2 mmol/L) depending on region and whether Systeme International (SI) units are utilized-in the absence of secondary factors, resistance to conventional lipid-lowering therapies, and a high lifetime risk of acute pancreatitis. It is caused by biallelic pathogenic variants in the LPL gene encoding LPL, or 1 of 4 other related genes that encode proteins that interact with LPL. Affected individuals require a strict, lifelong very low-fat diet with <15% of energy from fat. Emerging therapies inhibiting apolipoprotein C-III show promise in reducing serum triglycerides and pancreatitis risk in patients with FCS. A multidisciplinary approach, encompassing dietary management, pharmacotherapy, and patient education, is pivotal in mitigating the significant morbidity associated with FCS.

Familial chylomicronemia: New perspectives

Familial chylomicronemia syndrome (FCS) is a very rare, underdiagnosed disorder that can cause abdominal pain and recurrent pancreatitis from childhood -potentially life-threatening- and chronic complications such as diabetes mellitus and exocrine pancreatic insufficiency. FCS affects the quality of life and mental health of those who suffer from it, aspects that must be taken into account in its treatment, based on a strict low-fat diet, which is difficult to adhere to and persist. People with FCS lack the lipolytic capacity to hydrolyze triglycerides (TG) and have a minimal or null response to conventional lipid-lowering treatments. ApoCIII antagonists, specifically volanesorsen, olezarsen and ARO-APOC3, are the most promising drugs to reduce TG concentrations in patients with FCS. Anti-ANGPTL3 therapies appear to be less effective. More clinical trials and new pharmacological treatments are needed to improve the quality of life and prognosis of people with FCS.

Comprehensive analysis of Chinese patients with non-LPL familial chylomicronemia syndrome: Genetic variants, dietary interventions, and clinical insights

BACKGROUND

Familial chylomicronemia syndrome (FCS) comprises a group of ultrarare disorders caused by biallelic variants in LPL or, less frequently, by GPIHBP1, APOC2, APOA5, or LMF1.

OBJECTIVES

To evaluate the phenotypes and management of eight non-lipoprotein lipase (LPL)-FCS patients.

METHODS

Seven pediatric and one adult patients with non-LPL-FCS were enrolled. Clinical features, treatment outcomes, and genetic profiles were assessed.

RESULTS

Among the 33 patients with FCS, 25 (76%) had LPL-FCS and eight (24%) had non-LPL-FCS; five had variants in GPIHBP1, one each in the LMF1, APOC2, and one with composite heterozygous variants in APOA5 and LPL. Twelve non-LPL variants were identified, five of which were novel variants in GPIHBP1 and two in LMF1. In silico predictions indicated that all novel variants might impact protein function. Elevated baseline triglyceride (TG) levels [22.9 (17.4-30.8) mmol/L, 2026.7 (1540.0-2728.5) mg/dL] were observed in all patients. Among the pediatric patients (7/7), chylomicronemia was the most common onset symptom. Acute pancreatitis was observed in only one patient with LMF1-FCS during pregnancy. The frequency of symptoms and lipid levels in the non-LPL-FCS group were slightly lower than those in the LPL-FCS group (P > 0.05). Dietary fat restriction reduced TG levels by 84.0% to 4.21 mmol/L (372.6 mg/dL, P < 0.01). Compared with other non-LPL-FCS patients, GPIHBP1-FCS patients experienced greater challenges in managing TG levels (P < 0.05).

CONCLUSION

This study unveiled the genetic profile of the Chinese FCS cohort and enriched the mutation spectrum of non-LPL-FCS. The clinical characteristics and treatment outcomes of patients with non-LPL-FCS were delineated.

Unmasking a Rare Genetic Mutation: The Importance of Genetic Testing in Refractory Hypertriglyceridemia

Background/Objective

Genetic causes of hypertriglyceridemia like familial chylomicronemia syndrome can be overlooked in everyday practice. We report a patient with a rare genetic mutation, highlighting the importance of genetic testing for timely diagnosis and prevention of complications.

Case Report

A 45-year-old Hispanic female presented with serum triglyceride levels of 749 mg/dL, refractory to rosuvastatin 10 mg daily and omega-3 ethyl esters 2 g daily. Initial studies showed total cholesterol of 278 mg/dL and high-density lipoprotein of 38 mg/dL. Physical examination was negative for hepatosplenomegaly and xanthoma, with no reported history of acute pancreatitis. Despite treatment escalation with gemfibrozil, fenofibrate, and icosapent ethyl, her triglyceride levels remained elevated, peaking at 4300 mg/dL. Seven years after presentation, genetic testing revealed homozygosity for c.11delC of the apolipoprotein A5 gene, confirming the diagnosis of familial chylomicronemia syndrome. Postdiagnosis, the patient adhered to a strict low-fat diet with daily fat intake of less than 15-20 g, limited simple sugars, refined carbohydrates, and alcohol, leading to a nadir of serum triglycerides of 197 mg/dL.

Discussion

The identified mutation is exceedingly rare (<0.01%), as most associated mutations involve the lipoprotein lipase gene. There are no approved therapies for genetic hypertriglyceridemia. The mainstay of treatment is a very low-fat diet to prevent complications.

Conclusion

We underscore the importance of genetic testing in refractory hypertriglyceridemia despite a lack of clinical signs. A definitive diagnosis can alleviate patient burden, improve therapeutic adherence, and enhance the patient-physician relationship.

Characteristics, Physiopathology and Management of Dyslipidemias in Pregnancy: A Narrative Review

Dyslipidemia is a significant risk factor for atherosclerotic cardiovascular disease (ASCVD). During pregnancy, physiological changes elevate cholesterol and triglyceride levels to support fetal development, which can exacerbate pre-existing conditions and lead to complications such as pre-eclampsia, gestational diabetes, and increased ASCVD risk for both mother and child. Effective management strategies are necessary, especially for pregnant women with inherited forms of dyslipidemia (i.e., familial hypertriglyceridemia, hyperchylomicronemia), where personalized dietary adjustments are crucial for successful pregnancy outcomes. Pharmacological interventions and lipoprotein apheresis may be necessary for severe cases, though their use is often limited by factors such as cost, availability, and potential fetal risks. Despite the promise of advanced therapies, their widespread application remains constrained by limited studies and high costs. Thus, a personalized, multidisciplinary approach is essential for optimizing outcomes. This review provides a comprehensive overview of current strategies and evidence-based practices for managing dyslipidemia during pregnancy, emphasizing the balance of maternal and fetal health. Additionally, it discusses the physiological changes in lipid metabolism during pregnancy and their implications, particularly for women with inherited forms of dyslipidemia.

Dyslipidemia management in women of reproductive potential: An Expert Clinical Consensus from the National Lipid Association

Cardiovascular disease (CVD) is the leading cause of death among women and its incidence has been increasing recently, particularly among younger women. Across major professional society guidelines, dyslipidemia management remains a central tenet for atherosclerotic CVD prevention for both women and men. Despite this, women, particularly young women, who are candidates for statin therapy are less likely to be treated and less likely to achieve their recommended therapeutic objectives for low-density lipoprotein cholesterol (LDL-C) levels. Elevated LDL-C and triglycerides are the two most common dyslipidemias that should be addressed during pregnancy due to the increased risk for adverse pregnancy outcomes, such as preeclampsia, gestational diabetes mellitus, and pre-term delivery, as well as pancreatitis in the presence of severe hypertriglyceridemia. In this National Lipid Association Expert Clinical Consensus, we review the roles of nutrition, physical activity, and pharmacotherapy as strategies to address elevated levels of LDL-C and/or triglycerides among women of reproductive age. We include a special focus on points to consider during the shared decision-making discussion regarding pharmacotherapy for dyslipidemia during preconception planning, pregnancy, and lactation.

Pancreatic and cardiometabolic complications of severe hypertriglyceridaemia

PURPOSE OF REVIEW

This review endeavours to explore the aetiopathogenesis and impact of severe hypertriglyceridemia (SHTG) and chylomicronaemia on cardiovascular, and pancreatic complications and summarizes the novel pharmacological options for management.

RECENT FINDINGS

SHTG, although rare, presents significant diagnostic and therapeutic challenges. Familial chylomicronaemia syndrome (FCS), is the rare monogenic form of SHTG, associated with increased acute pancreatitis (AP) risk, whereas relatively common multifactorial chylomicronaemia syndrome (MCS) leans more towards cardiovascular complications. Despite the introduction and validation of the FCS Score, FCS continues to be underdiagnosed and diagnosis is often delayed. Longitudinal data on disease progression remains scant. SHTG-induced AP remains a life-threatening concern, with conservative treatment as the cornerstone while blood purification techniques offer limited additional benefit. Conventional lipid-lowering medications exhibit minimal efficacy, underscoring the growing interest in novel therapeutic avenues, that is, antisense oligonucleotides (ASO) and short interfering RNA (siRNA) targeting apolipoprotein C3 (ApoC3) and angiopoietin-like protein 3 and/or 8 (ANGPTL3/8).

SUMMARY

Despite advancements in understanding the genetic basis and pathogenesis of SHTG, diagnostic and therapeutic challenges persist. The rarity of FCS and the heterogenous phenotype of MCS underscore the need for the development of predictive models for complications and tailored personalized treatment strategies. The establishment of national and international registries is advocated to augment disease comprehension and identify high-risk individuals.

Dietary lauric acid promoted antioxidant and immune capacity by improving intestinal structure and microbial population of swimming crab (Portunus trituberculatus)

Lauric acid (LA), a saturated fatty acid with 12 carbon atoms, is widely regarded as a healthy fatty acid that plays an important role in disease resistance and improving immune physiological function. The objective of this study was to determine the effects of dietary lauric acid on the growth performance, antioxidant capacity, non-specific immunity and intestinal microbiology, and evaluate the potential of lauric acids an environmentally friendly additive in swimming crab (Portunus trituberculatus) culture. A total of 192 swimming crabs with an initial body weight of 11.68 ± 0.02 g were fed six different dietary lauric acid levels, the analytical values of lauric acid were 0.09, 0.44, 0.80, 1.00, 1.53, 2.91 mg/g, respectively. There were four replicates per treatment and 8 juvenile swimming crabs per replicate. The results indicated that final weight, percent weight gain, specific growth rate, survival and feed intake were not significantly affected by dietary lauric acid levels; however, crabs fed diets with 0.80 and 1.00 mg/g lauric acid showed the lowest feed efficiency among all treatments. Proximate composition in hepatopancreas and muscle were not significantly affected by dietary lauric acid levels. The highest activities of amylase and lipase in hepatopancreas and intestine were found at crabs fed diet with 0.80 mg/g lauric acid (P < 0.05), the activity of carnitine palmityl transferase (CPT) in hepatopancreas and intestine significantly decreased with dietary lauric acid levels increasing from 0.09 to 2.91 mg/g (P < 0.05). The lowest concentration of glucose and total protein and the activity of alkaline phosphatase in hemolymph were observed at crabs fed diets with 0.80 and 1.00 mg/g lauric acid among all treatments. The activity of GSH-Px in hepatopancreas significantly increased with dietary lauric acid increasing from 0.09 to 1.53 mg/g, MDA in hepatopancreas and hemolymph was not significantly influenced by dietary lauric acid levels. The highest expression of cat and gpx in hepatopancreas were exhibited in crabs fed diet with 1.00 mg/g lauric acid, however, the expression of genes related to the inflammatory signaling pathway (relish, myd88, traf6, nf-κB) were up-regulated in the hepatopancreas with dietary lauric acid levels increasing from 0.09 to 1.00 mg/g, moreover, the expression of genes related to intestinal inflammatory, immune and antioxidant were significantly affected by dietary lauric acid levels (P < 0.05). Crabs fed diet without lauric acid supplementation exhibited higher lipid drop area in hepatopancreas than those fed the other diets (P < 0.05). The expression of genes related to lipid catabolism was up-regulated, however, and the expression of genes related to lipid synthesis was down-regulated in the hepatopancreas of crabs fed with 0.80 mg/g lauric acid. Lauric acid improved hepatic tubular integrity, and enhanced intestinal barrier function by increasing peritrophic membrane (PM) thickness and upregulating the expression of structural factors (per44, zo-1) and intestinal immunity-related genes. In addition, dietary 1.00 mg/g lauric acid significantly improved the microbiota composition of the intestinal, increased the abundance of Actinobacteria and Rhodobacteraceae, and decreased the abundance of Vibrio, thus maintaining the microbiota balance of the intestine. The correlation analysis showed that there was a relationship between intestinal microbiota and immune-antioxidant function. In conclusion, the dietary 1.00 mg/g lauric acid is beneficial to improve the antioxidant capacity and intestinal health of swimming crab.

Clinical characterization and mutation spectrum of patients with hypertriglyceridemia in a German outpatient clinic

BACKGROUND

Severe hypertriglyceridemia (HTG) has predominantly multifactorial causes (MCS). Yet a small subset of patients have the monogenetic form (FCS). It remains a challenge to distinguish patients clinically, since decompensated MCS might mimic FCS´s severity. Aim of the current study was to determine clinical criteria that could sufficiently distinguish both forms as well as to apply the FCS score proposed by Moulin and colleagues.

METHODS

We retrospectively studied 72 patients who presented with severe HTG in our clinic during a time span of seven years and received genetic testing. We classified genetic variants (ACMG-criteria), followed by genetic categorization into MCS or FCS. Clinical data were gathered from the medical records and the FCS score was calculated for each patient.

RESULTS

Molecular genetic screening revealed eight FCS patients and 64 MCS patients. Altogether, we found 13 pathogenic variants of which four have not been described before. The FCS patients showed a significantly higher median triglyceride level compared to the MCS. The FCS score yielded a sensitivity of 75% and a specificity of 93.7% in our cohort, and significantly differentiated between the FCS and MCS group (p<0.001).

CONCLUSIONS

In our cohort we identified several variables that significantly differentiated FCS from MCS. The FCS score performed similar to the original study by Moulin, thereby further validating the discriminatory power of the FCS score in an independent cohort.

Diagnosis and stabilisation of familial chylomicronemia syndrome in two infants presenting with hypertriglyceridemia-induced acute pancreatitis

Familial chylomicronemia syndrome (FCS) is a rare disorder of triglyceride (TG) metabolism caused by loss of function variants in one of five known canonical genes involved in chylomicron lipolysis and clearance-LPL, APOC2, APOA5, LMF1, and GPIHBP1. Pathogenic variants in LPL, which encodes the hydrolytic enzyme lipoprotein lipase, account for over 80%-90% of cases. FCS may present in infancy with hypertriglyceridemia-induced acute pancreatitis and is challenging to manage both acutely and in the long-term. Here, we report our experience managing two unrelated infants consecutively diagnosed with hypertriglyceridemia-induced acute pancreatitis caused by LPL deficiency. Both had elevated TGs at presentation (205 and 30 mmol/L, respectively) and molecular genetic testing confirmed each infant carried a different homozygous pathogenic variant in the LPL gene, specifically, c.987C>A (p.Tyr329Ter) and c.632C>A (p.Thr211Lys). The more severely affected infant had cutaneous xanthomata, lipemia retinalis and lipemic plasma at presentation, and required management in an intensive care setting. Acute stabilisation was achieved using insulin and heparin infusions together with the iterative implementation of a fat-restricted diet, low in long chain triglycerides (LCT) and supplemented with medium chain triglycerides (MCT). In both cases, provision of adequate caloric intake (~110-120 kcal/kg/day) was also found to be important for a sustained TG reduction during the acute phase of management. In summary, a high index of suspicion is required to diagnose FCS in infants with hypertriglyceridemia-induced acute pancreatitis, management of which can be challenging, highlighting the need for more evidence-based recommendations.

Monogenic hypertriglyceridemia and recurrent pancreatitis in a homozygous carrier of a rare APOA5 mutation: a case report

BACKGROUND

Homozygous mutations in the APOA5 gene constitute a rare cause of monogenic hypertriglyceridemia, or familial chylomicronemia syndrome (FCS). We searched PubMed and identified 16 cases of homozygous mutations in the APOA5 gene. Severe hypertriglyceridemia related to monogenic mutations in triglyceride-regulating genes can cause recurrent acute pancreatitis. Standard therapeutic approaches for managing this condition typically include dietary interventions, fibrates, and omega-3-fatty acids. A novel therapeutic approach, antisense oligonucleotide volanesorsen is approved for use in patients with FCS.

CASE PRESENTATION

We report a case of a 25-years old Afghani male presenting with acute pancreatitis due to severe hypertriglyceridemia up to 29.8 mmol/L caused by homozygosity in APOA5 (c.427delC, p.Arg143Alafs*57). A low-fat diet enriched with medium-chain TG (MCT) oil and fibrate therapy did not prevent recurrent relapses, and volanesorsen was initiated. Volanesorsen resulted in almost normalized triglyceride levels. No further relapses of acute pancreatitis occurred. Patient reported an improve life quality due to alleviated chronic abdominal pain and headaches.

CONCLUSIONS

Our case reports a rare yet potentially life-threatening condition-monogenic hypertriglyceridemia-induced acute pancreatitis. The implementation of the antisense drug volanesorsen resulted in improved triglyceride levels, alleviated symptoms, and enhanced the quality of life.

Olezarsen, Acute Pancreatitis, and Familial Chylomicronemia Syndrome

BACKGROUND

Familial chylomicronemia syndrome is a genetic disorder associated with severe hypertriglyceridemia and severe acute pancreatitis. Olezarsen reduces the plasma triglyceride level by reducing hepatic synthesis of apolipoprotein C-III.

METHODS

In a phase 3, double-blind, placebo-controlled trial, we randomly assigned patients with genetically identified familial chylomicronemia syndrome to receive olezarsen at a dose of 80 mg or 50 mg or placebo subcutaneously every 4 weeks for 49 weeks. There were two primary end points: the difference between the 80-mg olezarsen group and the placebo group in the percent change in the fasting triglyceride level from baseline to 6 months, and (to be assessed if the first was significant) the difference between the 50-mg olezarsen group and the placebo group. Secondary end points included the mean percent change from baseline in the apolipoprotein C-III level and an independently adjudicated episode of acute pancreatitis.

RESULTS

A total of 66 patients underwent randomization; 22 were assigned to the 80-mg olezarsen group, 21 to the 50-mg olezarsen group, and 23 to the placebo group. At baseline, the mean (±SD) triglyceride level among the patients was 2630±1315 mg per deciliter, and 71% had a history of acute pancreatitis within the previous 10 years. Triglyceride levels at 6 months were significantly reduced with the 80-mg dose of olezarsen as compared with placebo (-43.5 percentage points; 95% confidence interval [CI], -69.1 to -17.9; P<0.001) but not with the 50-mg dose (-22.4 percentage points; 95% CI, -47.2 to 2.5; P = 0.08). The difference in the mean percent change in the apolipoprotein C-III level from baseline to 6 months in the 80-mg group as compared with the placebo group was -73.7 percentage points (95% CI, -94.6 to -52.8) and between the 50-mg group as compared with the placebo group was -65.5 percentage points (95% CI, -82.6 to -48.3). By 53 weeks, 11 episodes of acute pancreatitis had occurred in the placebo group, and 1 episode had occurred in each olezarsen group (rate ratio [pooled olezarsen groups vs. placebo], 0.12; 95% CI, 0.02 to 0.66). Adverse events of moderate severity that were considered by a trial investigator at the site to be related to the trial drug or placebo occurred in 4 patients in the 80-mg olezarsen group.

CONCLUSIONS

In patients with familial chylomicronemia syndrome, olezarsen may represent a new therapy to reduce plasma triglyceride levels. (Funded by Ionis Pharmaceuticals; Balance ClinicalTrials.gov number, NCT04568434.).

Transitional Medicine of Intractable Primary Dyslipidemias in Japan

Transitional medicine refers to the seamless continuity of medical care for patients with childhood-onset diseases as they grow into adulthood. The transition of care must be seamless in medical treatment as the patients grow and in other medical aids such as subsidies for medical expenses in the health care system. Inappropriate transitional care, either medical or social, directly causes poorer prognosis for many early-onset diseases, including primary dyslipidemia caused by genetic abnormalities. Many primary dyslipidemias are designated as intractable diseases in the Japanese health care system for specific medical aids, as having no curative treatment and requiring enormous treatment costs for lipid management and prevention of complications. However, there are problems in transitional medicine for primary dyslipidemia in Japan. As for the medical treatment system, the diagnosis rate remains low due to the shortage of specialists, their insufficient link with generalists and other field specialists, and poor linkage between pediatricians and physicians for adults. In the medical care system, there is a mismatch of diagnostic criteria of primary dyslipidemias between children and adults for medical care expense subsidization, as between The Program for the Specific Pediatric Chronic Diseases and the Program for Designated Adult Intractable Diseases. This could lead some patients subsidized in their childhood to no longer be under the coverage of the aids after transition. This review intends to describe these issues in transitional medicine of primary dyslipidemia in Japan as a part of the efforts to resolve the problems by the Committee on Primary Dyslipidemia under the Research Program on Rare and Intractable Disease of the Ministry of Health, Labour and Welfare of Japan.

Nutrition in Pediatric Patients and Vulnerable Populations: Updates and Advances

Nutrition is a modifiable factor of paramount importance for the prevention and attainment of health and the development of youngsters [...].

Exchange Transfusion: A Good Option for the Acute Treatment of Familial Chylomicronemia Syndrome in the Neonatal Period

Familial chylomicronemia syndrome (FCS) is one of the rare causes of hypertriglyceridemia. Plasmapheresis is recommended in patients with triglyceride levels greater than 2000 mg/dL. However, plasmapheresis is difficult to perform in most centers due to technical inadequacies in the neonatal period. There are some reports in the literature on the efficacy of exchange transfusion. The index case involves a 20-day-old male patient who was admitted to the emergency department for restlessness and poor feeding. He was born at term with a birth weight of 4000 g. He was exclusively breastfed. The patient was taken to the neonatal intensive care unit due to his plasma being in the form of excessive lipemia. The first measurable triglyceride level was 5100 mg/dL (57.6 mmol/L). Breast milk was restricted, and intravenous hydration was started. However, his triglyceride level did not decrease despite this treatment. Other laboratory values could not be read due to excessive lipemic serum. On the third day of hospitalization, an exchange transfusion was decided upon in this case due to the development of respiratory distress (oxygen support, tachypnea). After exchange transfusion, the patient's triglyceride level reduced dramatically to 592 mg/dL (6.6 mmol/L), and his respiratory symptoms resolved. The aim of this case report is to demonstrate that exchange transfusion therapy is a safe and effective treatment modality in the neonatal period for the acute management of FCS. Furthermore, dietary therapy restricted to long-chain fatty acids combined with medium-chain fatty acid supplementation is highly effective in the chronic management of these patients.

Understanding the Relationship between the Ketogenic Diet and the Heart: A Novel Therapeutic Potential for Cardiovascular Health

Obesity and cardiovascular diseases are major health problems worldwide, and weight loss is used as a treatment strategy to enhance various aspects. While there are many weight loss methods, one of the most effective is through a dietary approach. The ketogenic diet (KD), which is characterized by low carbohydrates and high levels of fat and/or protein, is used in obese patients as it is a promising treatment option for weight loss as well as for controlling the risk factors for cardiovascular diseases, as seen in its effects on cardio-metabolic outcomes, particularly in obesity, heart failure, and hypertension. In this review, we summarize the clinical evidence of the efficacy and safety of the KD in controlling risk factors for cardiovascular diseases and discuss the possible mechanisms of action based on recent evidence in understanding the influence of the KD at the cellular and molecular levels.

[A case of neonatal-onset type I hyperlipoproteinemia with bloody ascites]

This report presents a case of a male infant, aged 32 days, who was admitted to the hospital due to 2 days of bloody stools and 1 day of fever. Upon admission, venous blood samples were collected, which appeared pink. Blood biochemistry tests revealed elevated levels of triglycerides and total cholesterol. The familial whole genome sequencing revealed a compound heterozygous variation in the LPL gene, with one variation inherited from the father and the other from the mother. The patient was diagnosed with lipoprotein lipase deficiency-related hyperlipoproteinemia. Acute symptoms including bloody stools, fever, and bloody ascites led to the consideration of acute pancreatitis, and the treatment involved fasting, plasma exchange, and whole blood exchange. Following the definitive diagnosis based on the genetic results, the patient was given a low-fat diet and received treatment with fat-soluble vitamins and trace elements, as well as adjustments to the feeding plan. After a 4-week hospitalization, the patient's condition improved and he was discharged. Follow-up showed a decrease in triglycerides and total cholesterol levels. At the age of 1 year, the patient's growth and psychomotor development were normal. This article emphasizes the multidisciplinary diagnosis and treatment of familial hyperlipoproteinemia presenting with symptoms suggestive of acute pancreatitis, including bloody ascites, in the neonatal period.

Inhibition of Angiopoietin-Like Protein 3 or 3/8 Complex and ApoC-III in Severe Hypertriglyceridemia

PURPOSE OF REVIEW

The role of the inhibition of ANGPTL3 in severe or refractory hypercholesterolemia is well documented, less in severe hyperTG. This review focuses on the preclinical and clinical development of ApoC-III inhibitors and ANGPTL3, 4, and 3/8 complex inhibitors for the treatment of severe or refractory forms of hypertriglyceridemia to prevent cardiovascular disease or other morbidities.

RECENT FINDINGS

APOC3 and ANGPTL3 became targets for drug development following the identification of naturally occurring loss of function variants in families with a favorable lipid profile and low cardiovascular risk. The inhibition of ANGPTL3 covers a broad spectrum of lipid disorders from severe hypercholesterolemia to severe hypertriglyceridemia, while the inhibition of ApoC-III can treat hypertriglyceridemia regardless of the severity. Preclinical and clinical data suggest that ApoC-III inhibitors, ANGPTL3 inhibitors, and inhibitors of the ANGPTL3/8 complex that is formed postprandially are highly effective for the treatment of severe or refractory hypertriglyceridemia. Inhibition of ANGPTL3 or the ANGPTL3/8 complex upregulates LPL and facilitates the hydrolysis and clearance of triglyceride-rich lipoproteins (TRL) (LPL-dependent mechanisms), whereas ApoC-III inhibitors contribute to the management and clearance of TRL through both LPL-dependent and LPL-independent mechanisms making it possible to successfully lower TG in subjects completely lacking LPL (familial chylomicronemia syndrome). Most of these agents are biologicals including monoclonal antibodies (mAb), antisense nucleotides (ASO), small interfering RNA (siRNA), or CRISPR-cas gene editing strategies.

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.

Long-Term Nutritional Counseling for a Patient with Lipoprotein Lipase Deficiency

A one-year-and-nine-month-old Japanese boy was admitted with hypertriglyceridemia (fasting triglycerides 2548 mg/dL). After close examination, he was diagnosed with lipoprotein lipase (LPL) deficiency (compound heterozygous) and was immediately started on a fat-restricted dietary therapy. He responded well to the regimen (1200 kcal/day, 20 g fat/day) and his triglycerides decreased to 628 mg/dL within 7 days of starting the dietary therapy. It was decided to manage his illness without using any drugs because he was still an infant and responded well to a fat-restricted diet. During his hospital stay, dietitians provided him with nutritional counseling using a food exchange list, which was designed to easily calculate the fat content by including foods that are commonly served. His family quickly learned the skills to prepare a fat-restricted diet. Moreover, since dietary restrictions may have impaired the child's growth and development, the dietitians continued to intervene regularly after the child was discharged from the hospital. The dietitians confirmed that the patient was receiving nutritional intake appropriate for his growth and discussed the dietary concerns in his daily life and how to participate in school events that involved eating and drinking. Nutritional counseling was provided every 3-4 months from disease onset to age 23 years, except for a 14-month break at age 20 years. The patient grew up without developing acute pancreatitis, a serious complication of LPL deficiency. The long-term intervention of dieticians is necessary to achieve a balance between living on a strict diet for disease management and ensuring appropriate nutritional intakes for growth/development.

Long-Term Treatment of Lipoprotein Lipase Deficiency with Medium-Chain Triglyceride-Enriched Diet: A Case Series

Background: Lipoprotein lipase (LPL) deficiency is a genetic condition. Affected individuals typically develop symptoms related to severe and persistent hypertriglyceridemia, such as abdominal pain and recurrent pancreatitis, before 10 years of age. No pharmacological treatment sustainably lowering triglycerides (TGs) in LPL deficiency patients has been proven to be effective. This study investigated whether a long-chain triglyceride (LCT)-restricted, medium-chain triglyceride (MCT)-supplemented diet enables a meaningful reduction in TGs and reduces LPL-related symptoms in children with LPL deficiency. Methods: A single-center retrospective case series study of LPL deficiency patients treated at the Hospital of Sick Children between January 2000 and December 2022 was carried out. Data, extracted from hospital charts, included demographics, diagnosis confirmation, clinical and imaging observations, and biochemical profiles. Results: Seven patients with hypertriglyceridemia > 20 mmol/L suspected of an LPL deficiency diagnosis were included. Six patients had a confirmed molecular diagnosis of LPL deficiency, and one had glycogen storage disease type 1a (GSD1a). Clinical presentation was at a median of 30 days of age (range 1-105), and treatment start, excluding one late-treated patient, was at a median of 42 days (range 2-106). The observation and treatment period of the LPL patients was 48.0 patient years (median 7.1, range 4.3-15.5). The LCT-restricted and MCT-supplemented diet led to an immediate drop in TGs in six out of six LPL patients. TGs improved from a median of 40.9 mmol/L (range 11.4-276.5) pre-treatment to a median of 12.0 mmol/L (range 1.1-36.6) during treatment, total cholesterol from 7.6 mmol/L (4.9-27.0) to 3.9 mmol/L (1.7-8.2), and pancreatic lipase from 631 IU/L (30-1200) to 26.5 IU/L (5-289). In 48 patient years, there was only one complication of pancreatitis and no other disease-specific manifestations or complications. Catch-up growth was observed in one late-treated patient. All patients maintained normal growth and development. As expected, the diet failed to treat hypertriglyceridemia in the GSD1a patient. Conclusions: The dietary restriction of LCT in combination with MCT supplementation as long-term management of pediatric patients with LPL deficiency was feasible, well tolerated, and clinically effective in reducing TG levels and in preventing LPL-related complications.

Nutrition interventions for adults with dyslipidemia: A Clinical Perspective from the National Lipid Association

Lifestyle habits can have a profound impact on atherosclerotic cardiovascular disease (ASCVD) risk. The National Lipid Association previously published recommendations for lifestyle therapies to manage dyslipidemia. This Clinical Perspective provides an update with a focus on nutrition interventions for the three most common dyslipidemias in adults: 1) low-density lipoprotein cholesterol (LDL-C) elevation; 2) triglyceride (TG) elevation, including severe hypertriglyceridemia with chylomicronemia; and 3) combined dyslipidemia, with elevations in both LDL-C and TG levels. Lowering LDL-C and non-high-density lipoprotein cholesterol are the primary objectives for reducing ASCVD risk. With severe TG elevation (≥500 mg/dL), the primary objective is to prevent pancreatitis and ASCVD risk reduction is secondary. Nutrition interventions that lower LDL-C levels include reducing cholesterol-raising fatty acids and dietary cholesterol, as well as increasing intakes of unsaturated fatty acids, plant proteins, viscous fibers, and reducing adiposity for patients with overweight or obesity. Selected dietary supplements may be employed as dietary adjuncts. Nutrition interventions for all patients with elevated TG levels include restricting intakes of alcohol, added sugars, and refined starches. Additional lifestyle factors that reduce TG levels are participating in daily physical activity and reducing adiposity in patients with overweight or obesity. For patients with severe hypertriglyceridemia, an individualized approach is essential. Nutrition interventions for addressing concurrent elevations in LDL-C and TG include a combination of the strategies described for lowering LDL-C and TG. A multidisciplinary approach is recommended to facilitate success in making and sustaining dietary changes and the assistance of a registered dietitian nutritionist is highly recommended.

Severe Hypertriglyceridaemia and Chylomicronaemia Syndrome-Causes, Clinical Presentation, and Therapeutic Options

We have reviewed the genetic basis of chylomicronaemia, the difference between monogenic and polygenic hypertriglyceridaemia, its effects on pancreatic, cardiovascular, and microvascular complications, and current and potential future pharmacotherapies. Severe hypertriglyceridaemia (TG > 10 mmol/L or 1000 mg/dL) is rare with a prevalence of <1%. It has a complex genetic basis. In some individuals, the inheritance of a single rare variant with a large effect size leads to severe hypertriglyceridaemia and fasting chylomicronaemia of monogenic origin, termed as familial chylomicronaemia syndrome (FCS). Alternatively, the accumulation of multiple low-effect variants causes polygenic hypertriglyceridaemia, which increases the tendency to develop fasting chylomicronaemia in presence of acquired factors, termed as multifactorial chylomicronaemia syndrome (MCS). FCS is an autosomal recessive disease characterized by a pathogenic variant of the lipoprotein lipase (LPL) gene or one of its regulators. The risk of pancreatic complications and associated morbidity and mortality are higher in FCS than in MCS. FCS has a more favourable cardiometabolic profile and a low prevalence of atherosclerotic cardiovascular disease (ASCVD) compared to MCS. The cornerstone of the management of severe hypertriglyceridaemia is a very-low-fat diet. FCS does not respond to traditional lipid-lowering therapies. Several novel pharmacotherapeutic agents are in various phases of development. Data on the correlation between genotype and phenotype in FCS are scarce. Further research to investigate the impact of individual gene variants on the natural history of the disease, and its link with ASCVD, microvascular disease, and acute or recurrent pancreatitis, is warranted. Volanesorsen reduces triglyceride concentration and frequency of pancreatitis effectively in patients with FCS and MCS. Several other therapeutic agents are in development. Understanding the natural history of FCS and MCS is necessary to rationalise healthcare resources and decide when to deploy these high-cost low-volume therapeutic agents.

Nutritional Treatment of Hypertriglyceridemia in Childhood: From Healthy-Heart Counselling to Life-Saving Diet

Hypertriglyceridemia is a lipid disorder with a varying prevalence; it is very common if we consider triglyceride plasma values slightly above the threshold, whereas it is extremely rare if only severely elevated triglyceride levels are considered. In most cases, severe forms of hypertriglyceridemia are caused by genetic mutations in the genes that regulate triglyceride metabolism, thus leading to extreme triglyceride plasma values and acute pancreatitis risk. Secondary forms of hypertriglyceridemia are usually less severe and are mainly associated with weight excess, but they can also be linked to liver, kidney, endocrinologic, or autoimmune diseases or to some class of drugs. Nutritional intervention is the milestone treatment for patients with hypertriglyceridemia and it has to be modulated on the underlying cause and on triglyceride plasma levels. In pediatric patients, nutritional intervention must be tailored according to specific age-related energy, growth and neurodevelopment requests. Nutritional intervention is extremely strict in case of severe hypertriglyceridemia, whereas it is similar to good healthy nutritional habits counselling for mild forms, mainly related to wrong habits and lifestyles, and to secondary causes. The aim of this narrative review is to define different nutritional intervention for various forms of hypertriglyceridemia in children and adolescents.

Recent Apolipoprotein CIII trials

PURPOSE OF REVIEW

This review will briefly revise the evidence concerning the pharmacological inhibition of Apolipoprotein CIII (ApoCIII) in patients with hypertriglyceridemia.

RECENT FINDINGS

ApoCIII is a plasma apolipoprotein playing a major role in the metabolism of triglyceride-rich lipoproteins, namely chylomicrons and very-low-density lipoproteins as well as in the pathological processes involved in atherosclerosis. Therefore, ApoCIII is a potential new target for reducing plasma levels of TRLs and, thereby, cardiovascular risk. In recent years, there have been extensive preclinical and clinical pharmacological studies aimed at testing drugs directed against ApoCIII.

SUMMARY

In this review, firstly we will summarize the molecular function of ApoCIII in lipoprotein metabolism. Then, we will examine the lipid-lowering potential of the pharmacological inhibition of ApoCIII based on the results of clinical trial employing Volansesorsen, the first approved antisense therapeutic oligonucleotide against ApoCIII mRNA. The future perspectives for ApoCIII inhibition will be also revised.

Screening and Management of Dyslipidemia in Children and Adolescents

This review provides an overview of pediatric dyslipidemia emphasizing screening and treatment recommendations. The presence of risk factors for cardiovascular disease in childhood poses significant risk for the development of atherosclerotic cardiovascular disease and cardiovascular events in adulthood. While atherogenic dyslipidemia is the most common dyslipidemia seen in children and can be suspected based on the presence of risk factors (such as obesity), familial hypercholesterolemia can be found in children with no risk factors. As such, universal cholesterol screening is recommended to identify children with these disorders in order to initiate treatment and reduce the risk of future cardiovascular disease. Treatment of pediatric dyslipidemia begins with lifestyle modifications, but primary genetic dyslipidemias may require medications such as statins. As pediatric lipid disorders often have genetic or familial components, it is important that all physicians are aware that cardiovascular risk begins in childhood, and can both identify these disorders in pediatric patients and counsel their adult patients with dyslipidemia to have their children screened.

Efficacy and safety of lomitapide in familial chylomicronaemia syndrome

BACKGROUND AND AIMS

Familial chylomicronaemia syndrome (FCS) is a rare autosomal recessive disorder, resulting in elevated triglycerides (TGs), abdominal pain and pancreatitis. Treatment options are limited. Lomitapide, a microsomal triglyceride transfer protein inhibitor, is approved for the treatment of homozygous familial hypercholesterolaemia. Whether its therapeutic use may be extended to FCS remains unknown. The aim of this study was to evaluate the efficacy and safety of lomitapide in adult patients with FCS.

METHODS

The open-label, single-arm 'LOCHNES' study of lomitapide in FCS enrolled patients >18 years with genetically confirmed FCS, elevated fasting TG ≥ 750 mg/dL and history of pancreatitis. Patients were administered lomitapide to the maximum tolerated dose for 26 weeks. The primary endpoint was the percent change in TGs from baseline to Week 26.

RESULTS

Eighteen patients were enrolled with median baseline TG levels 1803.5 mg/dL (97.5% CI, 1452-2391 mg/dL). At Week 26, median fasting TGs were reduced to 305 mg/dL (97.5% CI 219-801 mg/dL; 70.5% reduction); median lomitapide dose was 35 mg/day; 13 patients achieved TGs ≤750 mg/dL. Adverse events were mild to moderate and mainly related to gastrointestinal tolerability. Liver imaging at baseline and Week 26 revealed hepatic fat increases from median 12.0%-32.5%, while median hepatic stiffness remained normal. No patient experienced acute pancreatitis or severe abdominal pain during lomitapide treatment.

CONCLUSIONS

Lomitapide is effective and well tolerated in reducing TGs in FCS patients with a history of pancreatitis. Larger studies are warranted to determine lomitapide effectiveness in FCS.

Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control

Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.

Safety and efficacy of therapies for chylomicronemia

INTRODUCTION

Primary chylomicronemia is characterized by pathological accumulation of chylomicrons in the plasma causing severe hypertriglyceridemia, typically >10 mmol/L (>875 mg/dL). Patients with the ultra-rare familial chylomicronemia syndrome (FCS) subtype completely lack lipolytic capacity and respond minimally to traditional triglyceride-lowering therapies. The mainstay of treatment is a low-fat diet, which is difficult to follow and compromises quality of life. New therapies are being developed primarily to prevent episodes of life-threatening acute pancreatitis.

AREAS COVERED

Antagonists of apolipoprotein (apo) C-III, such as the antisense oligonucleotide (ASO) volanesorsen, significantly reduce triglyceride levels in chylomicronemia. However, approval of and access to volanesorsen are restricted since a substantial proportion of treated FCS patients developed thrombocytopenia. Newer apo C-III antagonists, namely, the ASO olezarsen (formerly AKCEA-APOCIII-LRx) and short interfering RNA (siRNA) ARO-APOC3, appear to show efficacy with less risk of thrombocytopenia. Potential utility of antagonists of angiopoietin-like protein 3 (ANGPTL3) such as evinacumab and the siRNA ARO-ANG3 in subtypes of chylomicronemia remains to be defined.

EXPERT OPINION

Emerging pharmacologic therapies for chylomicronemia show promise, particularly apo C-III antagonists. However, these treatments are still investigational. Further study of their efficacy and safety in patients with both rare FCS and more common multifactorial chylomicronemia is needed.

Efficacy and safety of the apolipoprotein C-III inhibitor Volanesorsen: a systematic evaluation and meta-analysis

PURPOSE

Familial celiac disease syndrome (FCS) is a form of hypertriglyceridemia (HTG) caused by the accumulation of celiac particles. Currently, volanesorsen is considered to be used to treat patients with FCS and HTG to improve symptoms. To evaluate the effect of volanesorsen on lipid metabolism in patients with FCS, we performed a systematic evaluation and meta-analysis.

METHODS

A systematic search of PubMed, Embase, ClinicalTrials.gov, and the Cochrane Library was conducted, and the bibliographies of original articles were checked manually. The quality of the studies was assessed using the Cochrane Risk of Bias tool.

RESULTS

Four randomized, controlled trials involving 246 patients were analyzed in this study. Patients treated with volanesorsen showed (MD = -78.85%; 95% CI = -96.04 to -61.65, P = 0.67, I² = 0%) decrease in TG and (MD = -80.08%; 95% CI = -90.02 to -71.54, P = 0.25, I² = 29%) decrease in ApoC-III levels compared to patients in the placebo group showing a significant decrease. In addition, HDL-C increased (MD = 46.01% 95% CI = 41.03 to 50.99, P = 0.41, I² = 0%), NHDL-C decreased (MD = -32.12%; 95% CI = -44.39 to -19.85, P = 0.11, I² = 55%), VLDL-C decreased (MD = -65.88%; 95% CI = -83.97 to -47.79, P = 0.71, I² = 0%), apo A1 increased (MD = 13.12%; 95% CI = 7.83 to 18.40, P = 0.72, I² = 0%), and apoB increased (MD = 7.94 %; 95% CI = -1.90 to 17.78, P = 0.54, I² = 0%) all suggest that volanesorsen has an overall FCS with a therapeutic effect. However, LDL-C increased (MD = 99.59%; 95% CI = 69.19 to 130.00, P = 0.61, I² = 0%) and apo B48 decreased (MD = 82.89%; 95% CI = -100.88 to -64.91, P = 0.42, I² = 0%), showing an inverse effect, suggesting that volanesorsen's did not target all proteins of lipid metabolism.

New Therapies for Primary Hyperlipidemia

Primary hyperlipidemias include a heterogeneous set of monogenic and polygenic conditions characterized by a strong family aggregation, severe forms of hypercholesterolemia and/or hypertriglyceridemia, appearance early on life, and a high risk of cardiovascular events and/or recurrent pancreatitis. In real life, a small proportion of the primary hyperlipidemia cases is recognized and treated properly. Our goal is to present an update of current and upcoming therapies for patients with primary hyperlipidemia. Recently, new lipid-lowering medications have obtained authorization from the U.S. Food and Drug Administration and the European Medicines Agency. These drugs target metabolic pathways, including (adenosine 5'-triphosphates)-citrate lyase (bempedoic acid), proprotein convertase subtilisin/kexin 9 (inclisiran), apolipoprotein CIII (volanesorsen), and angiopoietin-like 3 (volanesorsen), that have additive effects with the actions of the currently available therapies (i.e., statins, ezetimibe or fibrates). We discuss the potential clinical indications for the novel medications. To conclude, the addition of these new medications to the therapeutic options for primary hyperlipidemia patients may increase the likelihood of achieving the treatment targets. Also, it could be a safer alternative for patients with side effects for the currently available drugs.

Eruptive Xanthomas: Importance of Recognition to Reduce Delay of Effective Triglyceride Reduction

Eruptive xanthomas are localized lipid deposits in the dermis and an important early clue to severe hypertriglyceridemia. These small erythematous or yellow papules that localize to the extensor surfaces of extremities, buttocks, and the back are often overlooked during routine visits secondary to poor familiarity and limited skin examinations. We present 3 cases of patients with eruptive xanthomas and severe hypertriglyceridemia who underwent skin biopsy and waited weeks to years before receiving effective treatment. We suggest the following to minimize the delay between presentation and effective management. First, perform a comprehensive skin examination. Second, be mindful of the association between metabolic syndrome or diabetes with severe hypertriglyceridemia. Third, evaluate the Four D's of secondary hypertriglyceridemia: Diet/Lifestyle, Drugs/Medications, and Diseases/Disorders of metabolism. Finally, initiate effective treatment promptly after recognition. This includes beginning with a minimal fat diet and appropriate pharmacological intervention to control triglycerides as outlined in recent guidelines.

Genetic Lipid Disorders Associated with Atherosclerotic Cardiovascular Disease: Molecular Basis to Clinical Diagnosis and Epidemiologic Burden

Genetic lipid disorders, ranging from common dyslipidemias such as familial hypercholesterolemia, lipoprotein (a), and familial combined hyperlipidemia to rare disorders including familial chylomicronemia syndrome and inherited hypoalphalipoproteinemias (ie, Tangier and fish eye diseases), affect millions of individuals in the United States and tens of millions around the world and are often undiagnosed in the general population. Clinicians should take into consideration the potential of inherited lipid disorders or syndromes when severe derangements in lipid parameters are observed. Patients' combined genotype and phenotype should be evaluated in conjunction with a host of environmental factors impacting their risk of atherosclerotic cardiovascular disease.

Childhood Hypertriglyceridemia: Is It Time for a New Approach?

PURPOSE OF REVIEW

Hypertriglyceridemia (HTG) is widely prevalent in youth. There is an unmet need for effective medications in the management of HTG in youth. The purpose of this review is to summarize the approach to HTG in acute and chronic settings, and highlight emerging therapies targeted at specific genes, proteins, and enzymes to selectively alter triglyceride (TG) metabolism.

RECENT FINDINGS

Genetic and lifestyle factors play a significant role in the pathophysiology of HTG. Severe elevation of TG poses a risk of acute pancreatitis, while mild-to-moderate HTG increases the risk for premature atherosclerotic cardiovascular disease (ASCVD) and, increasingly, has been linked with non-alcoholic fatty liver disease. Although a variety of therapeutic agents are in development, strict adherence to a heart healthy lifestyle, including dietary changes, remain the cornerstone of management for youth with HTG. In addition to lifestyle changes, pharmacological interventions, including fibrates, omega 3 fatty acids, and statins may be considered for management of moderate-to-severe HTG. In view of its association with premature cardiovascular disease (CVD), non-high-density-lipoprotein-C (non-HDL-C) is an important target for therapy in children with moderate HTG. Management of HTG is dependent on its etiology, concomitant symptoms, and degree of TG elevation. The last two decades have seen remarkable changes in drug development, specifically those that act through the lipoprotein lipase complex, including new targeted treatments such as inhibitors of apolipoprotein C3 and angiopoietin-like protein 3.

The Effect of a Fat-Restricted Diet in Four Patients with Familial Chylomicronemia Syndrome: A Long-Term Follow-Up Study

(1) Background: Familial chylomicronemia syndrome (FCS) is a very rare autosomal recessive disorder characterized by severely elevated triglycerides and clinical symptoms in early childhood mainly presenting with abdominal pain, acute pancreatitis and hepatosplenomegaly. Primary treatment is a lifelong very strict low-fat diet, which might be challenging in pediatric patients. So far, data about children with FCS are rare. The aim of this study was to show the familial chylomicronemia syndrome traffic light table for pediatric patients and to assess the dietary fat intake and impact on triglycerides in children with FCS. (2) Methods: We performed a retrospective analysis in four children (50% male) affected by FCS from the Department of Pediatrics and Adolescent Medicine, Medical University of Vienna between January 2002 and September 2020. (3) Results: The four patients presented with classical FCS symptoms and showed baseline triglycerides (TG) exceeding 30,000 mg/dL in two patients, 10,000 mg/dL and 2400 mg/dL in one patient each. After diagnosis, fat percentage of total daily caloric intake was decreased and resulted immediately in triglyceride reduction. In all patients, FCS was genetically confirmed by mutations in genes encoding lipoprotein lipase. Acute pancreatitis and hepatosplenomegaly disappeared under the fat-restricted diet. A FCS traffic light table was developed as a dietary tool for affected families. (4) Conclusions: A restriction of dietary fat between 10% to 26% of the total daily caloric intake was feasible and effective in the long-term treatment of genetically confirmed FCS in children and could reduce the risk for acute pancreatitis. The dietary tool, the pediatric FCS traffic light table and the age-appropriate portion sizes for patients between 1 to 18 years, supports children and their parents to achieve and adhere to the lifelong strict low-fat diet.

Hypertriglyceridaemia: contemporary management of a neglected cardiovascular risk factor

Hypertriglyceridaemia represents one of the most prevalent lipid abnormalities, however it is often eclipsed by focus on LDL cholesterol and is frequently overlooked by clinicians, despite it being an important cardiovascular risk factor. For most patients, hypertriglyceridaemia arises from a combination of environmental factors and multiple genetic variations with small effects. Even in cases with apparent familial clustering of hypertriglyceridaemia, a monogenetic cause is rarely identified. Common secondary causes include obesity, uncontrolled diabetes, alcohol, and various commonly used drugs. Correction of these factors, along with lifestyle optimisation, should be prioritised prior to commencing medication. The goal of drug treatment is to reduce the risk of cardiovascular disease in those with moderate hypertriglyceridaemia and the risk of pancreatitis in those with severe hypertriglyceridaemia. Recent and ongoing trials demonstrate the important role of triglycerides (TG) in determining residual risk in patients with cardiovascular disease (CVD) already established on statin therapy. Novel and emerging data on omega-3 fatty acids (high-dose icosapent ethyl) and the selective PPAR modulator pemafibrate are eagerly awaited and may provide further clarity for clinicians in determining which patients will benefit from TG lowering and help inform clinical guidelines. There are numerous novel therapies on the horizon that reduce TG by decreasing the activity of proteins that inhibit lipoprotein lipase such as apolipoprotein C-III (including Volanesorsen which was recently approved in Germany) and ANGPTL 3/4 which may offer promise for the future.

Familial chylomicronemia syndrome due to a heterozygous deletion of the chromosome 8 treated with the apoCIII inhibitor volanesorsen: A case report

RATIONALE

Familial chylomicronemia syndrome is a congenital, severe form of hypertriglyceridemia associated with increased risk of acute pancreatitis. Treatment options are limited.

PATIENT CONCERNS

A 52-year-old woman was referred with recurrent pancreatitis and severe hypertriglyceridemia to our lipid clinic.

DIAGNOSIS

Laboratory examination showed elevated serum triglyceride concentrations of 8090 mg/dL (90 mmol/L). Lipid electrophoresis showed a type V phenotype with positive chylomicrons. Genetic investigation revealed a novel heterozygous large deletion of the lipoprotein lipase gene on chromosome 8. A familial chylomicronemia syndrome was diagnosed. Other causes of hypertriglyceridemia were excluded.

INTERVENTIONS

Fibrates and diet did not lower triglyceride levels. Therefore, treatment with the apolipoprotein CIII (apoCIII) inhibitor volanesorsen was initiated.

OUTCOMES

After 3 months of treatment, a 90% reduction of triglycerides was observed. ApoCIII concentrations were reduced by 90% in the total and by 61% in the chylomicron-free serum. Treatment was well tolerated with only minor local reaction after the first application. The platelet count was monitored weekly and did not decrease <150 cells/μL.

LESSONS

This case report shows that inhibition of apoCIII potently reduces serum triglycerides in patients with heterozygous monogenetic deletion of the lipoprotein lipase gene. Follow-up will show the effect on recurrent episodes of pancreatitis.

Clinical Management of Hypertriglyceridemia in the Prevention of Cardiovascular Disease and Pancreatitis

Purpose of Review

Hypertriglyceridemia (HTG) is common and is a significant contributor to atherosclerosis and pancreatitis risk. Specific HTG treatments have had variable success in reducing atherosclerosis risk. Novel therapies for severe HTG treatment and pancreatitis risk reduction are likely to be available soon. These novel therapies are expected to have broader applications for more moderate HTG and atherosclerosis risk reduction as well.

Recent Findings

NHANES 2012 data has confirmed a reduction in average triglyceride (TG) levels in the US population. Dietary modification and weight reduction when needed remain the core treatment elements for all individuals with HTG, while statin therapy is a foundational pharmacologic care for atherosclerotic cardiovascular disease (ASCVD) event risk reduction. In addition, the REDUCE-IT study provides evidence for additional benefit from the use of high-dose icosapent ethyl (IPE) on top of background medical therapy in adults with moderate HTG and ASCVD or type 2 diabetes mellitus (T2D) and additional ASCVD risk factors. However, treatment with eicosapentaenoic acid (EPA) combined with docosahexanoic acid (DHA) did not reduce ASCVD in a similar population studied in the STRENGTH trial. Furthermore, novel therapeutics targeting PPAR-ɑ, as well as ApoC-III and AngPTL3, effectively lower TG levels in individuals with moderate and severe HTG, respectively. These treatments may have applicability for reducing risk from ASCVD among individuals with chylomicronemia; in addition, ApoC-III and AngPTL3 treatments may have a role in treating individuals with the rare monogenic familial chylomicronemia syndrome (FCS) at risk for acute pancreatitis (AP).

Summary

Residual ASCVD risk in individuals treated with contemporary care may be due in part to non-LDL lipid abnormalities including HTG. The findings from REDUCE-IT, but not STRENGTH, confirm that consumption of high-dose EPA may reduce ASCVD risk, while combination therapy of EPA plus DHA does not reduce ASCVD in a similar population. TG lowering likely reduces ASCVD risk in individuals with HTG, but ASCVD risk is multifactorial; the added benefit of IPE to contemporary preventive therapy is the consequence of differential non-TG biologic properties between the two fatty acids. Acute pancreatitis is more difficult to study prospectively since it is less common; however, TG lowering is likely critical for the care of at-risk individuals. Additional benefit from novel therapy that has an impact on this otherwise refractory condition is anticipated.

Recurrent Pancreatitis in a Pregnant Woman with Severe Hypertriglyceridemia Successfully Managed by Multiple Plasmapheresis

Hypertriglyceridemia (HTG) is a state of increased serum triglyceride (TG) affected by multigenetic and multifactorial causes. Serum TG concentration can be markedly elevated if exposed to precipitating factors, such as estrogen hormone and pregnancy. We report the case of a patient with severe HTG who suffered from recurrent pancreatitis during the second trimester of pregnancy conceived within vitro fertilization-embryo transfer (IVF-ET) and was successfully controlled by multiple sessions of plasmapheresis.

A 24-year-old pregnant woman was admitted because of a sudden onset of severe abdominal pain at 26 weeks of gestation conceived by IVF-ET. She has experienced recurrent pancreatitis despite low-fat diet and dyslipidemia medications allowed in pregnancy. At admission, serum amylase and lipase were elevated to 347 and 627 U/L, respectively, along with fasting TG to 4809 mg/dL. A clinical diagnosis of HTG-induced acute pancreatitis was made, and plasmapheresis was performed. After plasmapheresis, serum TG, amylase, and lipase levels decreased to 556 mg/dL, 60 U/L, and 69 U/L, respectively, along with subsequent pain relief. The patient underwent a total of nine sessions of plasmapheresis to retain serum TG lower than 1,000 mg/dL during pregnancy, with no further recurrence of acute pancreatitis. After delivery, the serum TG level was maintained below 500 mg/dL with a combination treatment of fenofibrate, statin, and ezetimibe.

Although severe HTG is usually asymptomatic, if exposed to precipitating factors, it can cause acute pancreatitis, a fatal complication. Early application of plasmapheresis may be a useful option in HTG-induced acute pancreatitis intractable to medical treatment; however, its indications, risks, and benefits should be carefully evaluated.