The burden of familial chylomicronemia syndrome from the patients’ perspective

Plozasiran for Managing Persistent Chylomicronemia and Pancreatitis Risk

BACKGROUND

Persistent chylomicronemia is a genetic recessive disorder that is classically caused by familial chylomicronemia syndrome (FCS), but it also has multifactorial causes. The disorder is associated with the risk of recurrent acute pancreatitis. Plozasiran is a small interfering RNA that reduces hepatic production of apolipoprotein C-III and circulating triglycerides.

METHODS

In a phase 3 trial, we randomly assigned 75 patients with persistent chylomicronemia (with or without a genetic diagnosis) to receive subcutaneous plozasiran (25 mg or 50 mg) or placebo every 3 months for 12 months. The primary end point was the median percent change from baseline in the fasting triglyceride level at 10 months. Key secondary end points were the percent change in the fasting triglyceride level from baseline to the mean of values at 10 months and 12 months, changes in the fasting apolipoprotein C-III level from baseline to 10 months and 12 months, and the incidence of acute pancreatitis.

RESULTS

At baseline, the median triglyceride level was 2044 mg per deciliter. At 10 months, the median change from baseline in the fasting triglyceride level (the primary end point) was -80% in the 25-mg plozasiran group, -78% in the 50-mg plozasiran group, and -17% in the placebo group (P<0.001). The key secondary end points showed better results in the plozasiran groups than in the placebo group, including the incidence of acute pancreatitis (odds ratio, 0.17; 95% confidence interval, 0.03 to 0.94; P = 0.03). The risk of adverse events was similar across groups; the most common adverse events were abdominal pain, nasopharyngitis, headache, and nausea. Severe and serious adverse events were less common with plozasiran than with placebo. Hyperglycemia with plozasiran occurred in some patients with prediabetes or diabetes at baseline.

CONCLUSIONS

Patients with persistent chylomicronemia who received plozasiran had significantly lower triglyceride levels and a lower incidence of pancreatitis than those who received placebo. (Funded by Arrowhead Pharmaceuticals; PALISADE ClinicalTrials.gov number, NCT05089084.).

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.

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.

Qualitative development of the PROMIS Profile v1.0-Familial Chylomicronemia Syndrome (FCS) 28

PURPOSE

Familial chylomicronemia syndrome (FCS) is a rare genetic disorder characterized by high triglyceride levels, significant disease burden, and negative impacts on health-related quality of life. This project aimed to create a PROMIS-based patient-reported outcome measure that represents valid and important concerns for patients with FCS.

METHODS

We reviewed the literature and data from a previous qualitative study of FCS to identify key FCS symptoms and impacts, which were mapped to PROMIS domains to create a pool of eligible items. Candidate items were reduced per expert feedback and patients with FCS completed cognitive interviews to confirm content validity and measure content.

RESULTS

Literature and qualitative data review identified ten key symptoms and 12 key impacts of FCS, including abdominal pain, fatigue, difficulty thinking, and worry about pancreatitis attacks. We identified 96 items primarily from PROMIS, supplemented with items from the Quality of Life in Neurological Disorders™ (Neuro-QoL™) and the Functional Assessment of Chronic Illness Therapy (FACIT) measurement systems. This pool was reduced to 32 candidate items, which were assessed via cognitive interviews with eight participants with FCS. Cognitive interview results and additional expert feedback led to the removal of four items and finalization of the PROMIS Profile v1.0-familial chylomicronemia syndrome (FCS) 28.

CONCLUSIONS

The PROMIS Profile v1.0-familial chylomicronemia syndrome (FCS) 28 provides strong content validity for assessing quality of life among patients with FCS. The benefits of PROMIS, including norm-referenced mean values for each measure, will facilitate comparison of patients with FCS to other clinical populations.

Causes, clinical findings and therapeutic options in chylomicronemia syndrome, a special form of hypertriglyceridemia

The prevalence of hypertriglyceridemia has been increasing worldwide. Attention is drawn to the fact that the frequency of a special hypertriglyceridemia entity, named chylomicronemia syndrome, is variable among its different forms. The monogenic form, termed familial chylomicronemia syndrome, is rare, occuring in 1 in every 1 million persons. On the other hand, the prevalence of the polygenic form of chylomicronemia syndrome is around 1:600. On the basis of the genetical alterations, other factors, such as obesity, alcohol consumption, uncontrolled diabetes mellitus and certain drugs may significantly contribute to the development of the multifactorial form. In this review, we aimed to highlight the recent findings about the clinical and laboratory features, differential diagnosis, as well as the epidemiology of the monogenic and polygenic forms of chylomicronemias. Regarding the therapy, differentiation between the two types of the chylomicronemia syndrome is essential, as well. Thus, proper treatment options of chylomicronemia and hypertriglyceridemia will be also summarized, emphasizing the newest therapeutic approaches, as novel agents may offer solution for the effective treatment of these conditions.

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.

Development of a novel PRO instrument for use in familial chylomicronemia syndrome

BACKGROUND

Familial chylomicronemia syndrome (FCS), a rare genetic disorder characterized by high levels of circulating triglycerides, negatively impacts multiple organs, including the liver and pancreas.

OBJECTIVE

The objective of this study was to develop and support the content validity of a novel patient-reported outcome (PRO) measure addressing FCS symptoms and impacts. To facilitate use in clinical trials of new treatments, evidence supporting the new measure needed to be consistent with regulatory guidance and requirements.

METHODS

A pool of items addressing symptoms and impacts of FCS was initially developed based on data from a large burden-of-illness study with patients with FCS as well as a review of available literature and existing PRO measures. Two rounds of qualitative interviews were conducted with patients with FCS (N = 10) to refine the draft items and support the measure's content validity. Each interview began with concept elicitation followed by cognitive debriefing of the draft FCS measure.

RESULTS

Patient-reported symptoms and impacts of FCS were generally consistent with those identified by the burden-of-illness study; abdominal pain was particularly prevalent and salient for patients. Suggested changes to the draft item pool were generally minor. Comprehensibility and ease of completion for the final instrument were confirmed during the second set of interviews.

CONCLUSION

The content validity of the final 17-item FCS Symptoms and Impacts Scale is strongly supported by patient input gathered through both a large burden-of-illness study and qualitative research. To further support use in clinical trials, psychometric evaluation of the measure is underway.

Current Diagnosis and Management of Primary Chylomicronemia

Primary chylomicronemia (PCM) is a rare and intractable disease characterized by marked accumulation of chylomicrons in plasma. The levels of plasma triglycerides (TGs) typically range from 1,000 - 15,000 mg/dL or higher.

PCM is caused by defects in the lipoprotein lipase (LPL) pathway due to genetic mutations, autoantibodies, or unidentified causes. The monogenic type is typically inherited as an autosomal recessive trait with loss-of-function mutations in LPL pathway genes ( LPL , LMF1 , GPIHBP1 , APOC2 , and APOA5 ). Secondary/environmental factors (diabetes, alcohol intake, pregnancy, etc.) often exacerbate hypertriglyceridemia (HTG).

The signs, symptoms, and complications of chylomicronemia include eruptive xanthomas, lipemia retinalis, hepatosplenomegaly, and acute pancreatitis with onset as early as in infancy. Acute pancreatitis can be fatal and recurrent episodes of abdominal pain may lead to dietary fat intolerance and failure to thrive.

The main goal of treatment is to prevent acute pancreatitis by reducing plasma TG levels to at least less than 500-1,000 mg/dL. However, current TG-lowering medications are generally ineffective for PCM. The only other treatment options are modulation of secondary/environmental factors. Most patients need strict dietary fat restriction, which is often difficult to maintain and likely affects their quality of life.

Timely diagnosis is critical for the best prognosis with currently available management, but PCM is often misdiagnosed and undertreated. The aim of this review is firstly to summarize the pathogenesis, signs, symptoms, diagnosis, and management of PCM, and secondly to propose simple diagnostic criteria that can be readily translated into general clinical practice to improve the diagnostic rate of PCM. In fact, these criteria are currently used to define eligibility to receive social support from the Japanese government for PCM as a rare and intractable disease.

Nevertheless, further research to unravel the molecular pathogenesis and develop effective therapeutic modalities is warranted. Nationwide registry research on PCM is currently ongoing in Japan with the aim of better understanding the disease burden as well as the unmet needs of this life-threatening disease with poor therapeutic options.

Effectiveness and safety of lomitapide in a patient with familial chylomicronemia syndrome

BACKGROUND

Familial chylomicronemia syndrome (FCS) is characterized by severe fasting hypertriglyceridemia, abdominal pain, and recurrent acute pancreatitis. Available triglyceride-lowering drugs are insufficient to avoid pancreatitis. Therefore, there is a significant unmet medical need for effective triglyceride-lowering drugs for patients with FCS.

CASE REPORT

We report the second case of a patient with FCS and recurrent pancreatitis treated with lomitapide. Lomitapide treatment resulted in a reduction of fasting TG levels from 2897 mg/dL (32.71 mmol/L) to an average of 954 mg/dL (10.77 mmol/L) on the 30 mg lomitapide equating to a 67% reduction from baseline. After 26 months of lomitapide treatment, histological activity score for hepatic fibrosis was stable although liver biopsy showed a marked increase of liver steatosis and mild perivenular and perisinusoidal fibrosis.

CONCLUSIONS

Lomitapide is effective in reducing triglycerides in FCS and preventing the recurrence of acute pancreatitis. A longer follow-up is necessary to evaluate long-term risk of progression toward severe stages of liver fibrosis. A prospective clinical trial may identify which subgroup of FCS patients would benefit from lomitapide treatment in the absence of significant liver adverse effects.

THE PREVALENCE OF PROBABLE FAMILIAL CHYLOMICRONEMIA SYNDROME IN A SOUTHERN CALIFORNIA POPULATION

OBJECTIVE

To estimate the prevalence of probable familial chylomicronemia syndrome (FCS) in a major Southern California Academic Center as well as to provide a systematic review of past FCS studies and management recommendations.

METHODS

Electronic medical records were queried based on single fasting plasma triglyceride (TG) levels of ≥880 mg/dL and at least 1 episode of acute pancreatitis. After the exclusion of secondary causes (diabetes, alcohol misuse, gallbladder disease, chronic kidney disease, uncontrolled hypothyroidism, estrogen, and drug use) and responses to lipid-lowering treatment, probable patients with FCS were identified. A systematic review of all published literature on the prevalence and management guidelines for FCS was then presented and discussed.

RESULTS

Out of 7 699 288 charts queried, 138 patients with TG levels of ≥880 mg/dL and documented evidence of at least 1 episode of acute pancreatitis were identified. Nine patients did not have any documented secondary causes of chylomicronemia. Four of the 9 patients had >20% decrease in TG levels after lipid-lowering treatment, 2 patients were not responsive to lipid-lowering medication, and data on lipid-lowering medications were missing in 3 patients.

CONCLUSION

Our study estimates the prevalence of probable FCS at a range of 0.26 to 0.66 per million. Using the recommended criteria, probable FCS cases can be identified to allow early diagnosis and management.

Estimating health state utilities associated with a rare disease: familial chylomicronemia syndrome (FCS)

Aims: Familial chylomicronemia syndrome (FCS) is a rare genetic disorder with no currently approved therapies. Treatments are in development, and cost-utility analyses will be needed to examine their value. These models will require health state utilities representing FCS. Therefore, the purpose of this study was to estimate utilities for FCS and an associated episode of acute pancreatitis (AP).Methods: Because it is not feasible to gather a large enough sample of patients with this extremely rare condition to complete standardized preference-based measures, vignette-based methods were used to estimate utilities. In time trade-off interviews, general population participants in the UK and Canada valued health state vignettes drafted based on literature review, clinician input, and interviews with patients. Four health states described variations of FCS. A fifth health state, describing AP, was added to one of the other health states to evaluate its impact on utility.Results: A total of 308 participants provided utility data (208 UK; 100 Canada). Mean utilities for FCS health states ranged from 0.46 to 0.83, with higher triglycerides, more severe symptoms, and a history of AP associated with lower utility values. The disutility (i.e. utility decrease) of AP ranged from -0.17 to -0.25, with variations depending on the health state to which it was added. Utility means were similar in the UK and Canada.Conclusions: The vignette-based approach is useful for estimating utilities of a rare disease. The health state utilities derived in this study would be useful in models examining cost-effectiveness of treatments for FCS.

Familial Chylomicronemia Syndrome (FCS): Recent Data on Diagnosis and Treatment

PURPOSE OF REVIEW

Familial chylomicronemia syndrome (FCS) is a rare recessive genetic disorder often underdiagnosed with potentially severe clinical consequences. In this review, we describe the clinical and biological characteristics of the disease together with its main complication, i.e., acute pancreatitis. We focused the paper on new diagnostic tools, progress in understanding the role of two key proteins (apolipoprotein CIII (apo CIII) and angiopoietin-like3 (ANGPTL-3)), and new therapeutic options.

RECENT FINDINGS

Recently, a new diagnostic tool has been proposed by European experts to help identify these patients. This tool with two recently identified parameters (low LDL and low body mass index) can help identify patients who should be genetically tested or who may have the disease when genetic testing is not available. FCS is caused by homozygous or compound heterozygous mutations of lipoprotein lipase, apolipoprotein C-II, apolipoprotein A-V, glycosylphosphatidylinositol anchored high-density lipoprotein-binding protein 1, and lipase maturation factor. Two proteins have been identified as important player in the metabolism of triglyceride-rich lipoprotein and its regulation. These two proteins are therapeutic target. Antisense oligonucleotide targeting apo CIII has been shown to significantly decrease triglyceride levels even in FCS and is the first available treatment for these patients. Further development might identify new compounds with reduced risk to develop severe thrombocytopenia. ANGPTL-3 inhibitors have not yet been tested in FCS patients but exert significant hypotriglyceridemic effect in the more frequent and less severe polygenic forms. Beyond these two new targets, microsomal triglyceride transfer protein (MTTP) inhibitors could also be part of the armamentarium, if on-going trials confirm their efficacy. New clinical tools and simple criteria can help select patients with possible FCS and identify patients who should have a genetic testing. Identifying patients with FCS is a major issue since these patients have a high risk to suffer severe episodes of acute pancreatitis and may now benefit from new therapeutic options including antisense oligonucleotide targeting apo CIII.

Analysis of a Chinese Pedigree With Familial Chylomicronemia Syndrome Reveals Two Novel LPL Mutations by Whole-Exome Sequencing

Familial chylomicronemia syndrome (FCS) is a rare monogenic autosomal recessive disease caused by loss-of-function mutations in genes involved in chylomicron breakdown through hydrolysis of triglycerides into free fatty acids. Patients are often diagnosed in early childhood with extremely high triglyceride levels and symptoms including abdominal pain, eruptive cutaneous xanthomata, hepatosplenomegaly, and significant cognitive, psychological, and social impairment. The most serious medical condition suffered by FCS patients is recurrent acute pancreatitis. Lipoprotein lipase (LPL) gene mutation accounts for majority of the known pathogenic mutations. Early diagnosis and strict low-fat diet are critical for successful management of the triglyceride concentration to lower the risk of pancreatitis. The true prevalence of FCS in China is unknown and here we report a Chinese female preterm neonate presented with an extremely high triglyceride level of 22.11 mmol/L on day 13 after birth. Clinical and laboratory workup including whole-exome sequencing revealed two novel compound heterozygous LPL mutations (c.406G > C and c.829G > C) that are co-segregated with her non-consanguineous parents, consistent with autosomal recessive inheritance. A diagnosis of FCS based on clinical, biochemical, and genetic ground was made to guide her management.

AAV-Mediated ApoC2 Gene Therapy: Reversal of Severe Hypertriglyceridemia and Rescue of Neonatal Death in ApoC2-Deficient Hamsters

Apolipoprotein C2 (ApoC2) is a key activator of lipoprotein lipase for plasma triglyceride metabolism. ApoC2-deficient patients present with severe hypertriglyceridemia and recurrent acute pancreatitis, for whom the only effective treatment is the infusion of normal plasma containing ApoC2. However, since ApoC2 has a fast catabolic rate, a repeated infusion is required, which limits its clinical use. To explore a safe and efficient approach for ApoC2 deficiency, we herein established an adeno-associated virus expressing human ApoC2 (AAV-hApoC2) to evaluate the efficacy and safety of gene therapy in ApoC2-deficient hypertriglyceridemic hamsters. Administration of AAV-hApoC2 via jugular or orbital vein in adult and neonatal ApoC2-deficient hamsters, respectively, could prevent the neonatal death and effectively improve severe hypertriglyceridemia of ApoC2-deficient hamsters without side effects in a long-term manner. Our novel findings in the present study demonstrate that AAV-hApoC2-mediated gene therapy will be a promising therapeutic approach for clinical patients with severe hypertriglyceridemia caused by ApoC2 deficiency.

PROMIS® and Neuro-QoLTM measures are valid measures of health-related quality of life among patients with familial chylomicronemia syndrome

Background: FCS significantly affects health-related quality of life (HRQOL). Legacy patient-reported outcome measures are often not sensitive to FCS's impact. NIH PROMIS and Neuro-QoL measures may accurately capture HRQOL in FCS patients. This study assessed a broad range of PROMIS and Neuro-QoL measures covering physical, mental, and social HRQOL to determine their suitability for the FCS population.Methods: Adult FCS patients in the United States (N = 25) were recruited to an online survey study and completed several PROMIS short forms and Neuro-QoL computer adaptive tests.Results: Scores were more than 0.5 standard deviations (SD) worse than the normative mean on 10 of 16 normed measures, and more than 0.75 SDs worse than the normative mean on two measures. Responses at the floor and ceiling were occasionally observed, marginal reliabilities were strong, and significant differences across performance status (ps < 0.05) provided preliminary support for construct validity. The measures correlated with each other strongly and as expected.Conclusion: Results support the ability of PROMIS and Neuro-QoL measures to detect HRQOL impairment among patients with FCS. PROMIS and Neuro-QoL measures captured the functional impact and symptom burden associated with FCS, and the broad range of symptom severity experienced by patients with FCS.

Familial chylomicronemia syndrome: an under-recognized cause of severe hypertriglyceridaemia

Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disorder of chylomicron metabolism causing severe elevation of triglyceride (TG) levels (>10 mmol L^-1 ). This condition is associated with a significant risk of recurrent acute pancreatitis (AP). AP caused by hypertriglyceridaemia (HTG) has been associated with a worse prognosis and higher mortality rates compared to pancreatitis of other aetiology. Despite its association with poor quality of life and increased lifelong risk of HTG-AP, few healthcare providers are familiar with FCS. Because this condition is under-recognized, the majority of FCS patients are diagnosed after age 20 often after consulting several physicians. Although other forms of severe HTG such as multifactorial chylomicronemia have been associated with high atherosclerotic cardiovascular disease (ASCVD) risk and metabolic abnormalities, ASCVD and metabolic syndrome are not usually observed in FCS patients. Because FCS is a genetic condition, the optimal diagnosis strategy remains genetic testing. The presence of bi-allelic pathogenic mutations in LPL, APOC2, GPIHBP1, APOA5 or LMF1 genes confirms the diagnosis. However, some cases of FCS caused by autoantibodies against LPL or GPIHBP1 proteins have also been reported. Furthermore, a clinical score for the diagnosis of FCS has been proposed but needs further validation. Available treatment options to lower triglycerides such as fibrates or omega-3 fatty acids are not efficacious in FCS patients. Currently, the cornerstone of treatment remains a lifelong very low-fat diet, which prevents the formation of chylomicrons. Finally, inhibitors of apo C-III and ANGPTL3 are in development and may eventually constitute additional treatment options for FCS patients.

Case report of one month and 15 days old baby with type V hyperlipoproteinemia (HLP)

BACKGROUND

Most of the patients with type 1 and V hyperlipoproteinemia (HLP) present with symptoms and signs of acute pancreatitis due to marked elevation of triglycerides, but this baby presented with a chest infection, which was later diagnosed as type V HLP on laboratory workup.

CASE PRESENTATION

We report a case of a 1 month and 15 days old baby boy, product of 2-nd degree consanguinity admitted to a nearby hospital with complaints of refusal to feed, cough and excessive crying. On examination his heart rate was 102 beats/min, respiratory rate was 55 breaths/min and temperature was within the normal range, provisional diagnosis of Pneumonia was made. His samples were tested at our laboratory, the lipid Profile at age of 1 month 15 days showed total cholesterol (TC) of 1400 mg/dl reference range (RR < 200 mg/dl), triglycerides (TG) of > 885 mg/dl after dilution it was 31,400 mg/dl (RR < 150 mg/dl), High density Cholesterol (HDL) of 35 mg/dl (RR > 40 mg/dl) and low density cholesterol (LDL) of 200 mg/dl (RR < 100 mg/dl). The patient's blood sample was grossly milky and lipemic in appearance. A "Refrigerator test" was performed after overnight storage of the sample in refrigerator at 4 °C, which gave a creamy layer at the top and clear infranatant due to caking of the Chylomicrons. Lipoprotein electrophoresis performed 1 month later showed Chylomicrons of 4.7% (RR 0-2%), Pre-beta lipoproteins of 51.5% (RR 5-22%), beta lipoproteins of 16.5% (RR 39-70%) and alpha of 27.3% (RR 23-53%). Initially he was diagnosed as type 1 HLP, but later on he was correctly diagnosed as type V HLP. Cholestyramine (Questran sachet) powder was started at a dose of 100 mg/kg on t.i.d basis with NAN-1 formula Milk at the age of 1 month and 15 days. On follow up, detailed advices regarding the weaning food was given to the mother (using olive oil in cooking, giving proteins and avoiding heavy fatty meals). His lipid profile was repeated at age of 3 months, which showed some improvement, his TGs were 1986 mg/dl and TC 105 mg/dl.

CONCLUSION

There is no universal diagnostic criterion for diagnosing Type V HLP, most likely, due to a scanty literature on this disorder. It stimulated us to report this case so that our findings may help for a timely diagnosis of the affected patients.

Significant Quality of Life Improvement Observed in a Patient With FCS Associated With a Marked Reduction in Triglycerides

Familial chylomicronemia syndrome (FCS) is a rare genetic disorder characterized by severely high triglycerides (TGs). It is associated with a marked increase in risk of recurrent, potentially fatal acute pancreatitis (AP), and symptoms including abdominal pain, fatigue, and anxiety that may substantially reduce quality of life (QoL). A 46-year-old woman with FCS and severely high TGs initially presented with necrotizing pancreatitis with pseudocysts, having previously experienced recurrent AP. The patient reported constant abdominal pain and fatigue, which were evident in her demeanor. Initial management included maximum doses of omega-3 fatty acids and fibrates, plus an extremely restricted diet (reduced intake: calories, fats, simple sugars; no alcohol). Despite adherence to all management strategies, TGs remained at approximately 2800 mg/dL (31.6 mmol/L) and symptoms persisted. The patient was enrolled in COMPASS, a phase 3, placebo-controlled trial to evaluate the effect of an investigational drug, volanesorsen, on fasting TGs in patients with hypertriglyceridemia (fasting TGs ≥ 500 mg/dL [≥5.7 mmol/L]). The woman, a confirmed FCS patient, continued into the open-label extension study, during which fasting TGs decreased to 146 mg/dL (1.7 mmol/L) following 4 months of treatment. The restrictive diet was maintained throughout treatment and no serious adverse events were reported. Along with sustained TG reduction, the patient experienced progressive, perceived improvements in observable QoL measures and a marked reduction in symptom severity and frequency. In a patient with FCS, reduction in TGs following volanesorsen therapy appeared to be associated with marked improvement in clinical symptoms and observed QoL.

A lipoprotein lipase-GPI-anchored high-density lipoprotein-binding protein 1 fusion lowers triglycerides in mice: Implications for managing familial chylomicronemia syndrome

Lipoprotein lipase (LPL) is central to triglyceride metabolism. Severely compromised LPL activity causes familial chylomicronemia syndrome (FCS), which is associated with very high plasma triglyceride levels and increased risk of life-threatening pancreatitis. Currently, no approved pharmacological intervention can acutely lower plasma triglycerides in FCS. Low yield, high aggregation, and poor stability of recombinant LPL have thus far prevented development of enzyme replacement therapy. Recently, we showed that LPL monomers form 1:1 complexes with the LPL transporter glycosylphosphatidylinositol-anchored high-density lipoprotein–binding protein 1 (GPIHBP1) and solved the structure of the complex. In the present work, we further characterized the monomeric LPL/GPIHBP1 complex and its derivative, the LPL–GPIHBP1 fusion protein, with the goal of contributing to the development of an LPL enzyme replacement therapy. Fusion of LPL to GPIHBP1 increased yields of recombinant LPL, prevented LPL aggregation, stabilized LPL against spontaneous inactivation, and made it resistant to inactivation by the LPL antagonists angiopoietin-like protein 3 (ANGPTL3) or ANGPTL4. The high stability of the fusion protein enabled us to identify LPL amino acids that interact with ANGPTL4. Additionally, the LPL–GPIHBP1 fusion protein exhibited high enzyme activity in in vitro assays. Importantly, both intravenous and subcutaneous administrations of the fusion protein lowered triglycerides in several mouse strains without causing adverse effects. These results indicate that the LPL–GPIHBP1 fusion protein has potential for use as a therapeutic for managing FCS.

Identifying suspected familial chylomicronemia syndrome

Familial chylomicronemia syndrome (FCS) is a rare lipid disorder posing significant clinical burdens on patients. Due to its rarity, variety of presentations, and lack of universal diagnostic criteria, patients see an average of five physicians before diagnosis. We screened adults for a triglyceride level ≥1000 mg/dL from September 2015 to September 2016 and a history of pancreatitis and performed a thorough chart review on those who met the criteria. An adjudication panel used a definition that also called for supportive information including history of hypertriglyceridemia or family history of pancreatitis/hypertriglyceridemia. Among 297,891 adults with laboratory values available, 334 (0.11%) had triglyceride levels ≥1000 mg/dL, and 30 (9%) of those had pancreatitis. Most of these 30 patients were male (73%), had diabetes (90%), were taking a fibrate (93%), and were taking a statin (80%). The average body mass index was 32.5 ± 4.5 kg/m2. Six cases were ruled out, primarily due to substance abuse and/or isolated pancreatitis. Of the 24 suspected FCS cases, the average maximum triglyceride level was 3085 ± 1211 mg/dL. Electronic screening methods based solely on triglycerides ≥1000 mg/dL and pancreatitis eliminated 99.99% of the population, enabling the adjudication panel to focus on 30 cases. In 24 cases, FCS could not be ruled out; hence, the prevalence of FCS may be as high as 1 in 12,413.

Characterizing familial chylomicronemia syndrome: Baseline data of the APPROACH study

BACKGROUND

Familial chylomicronemia syndrome (FCS) is a rare metabolic disorder caused by mutations in lipoprotein lipase (LPL) or genes required for LPL functionality and is characterized by hyperchylomicronemia that results in recurrent episodes of acute pancreatitis. Owing to the rarity of FCS, there are few case series describing the phenotypic variability in FCS patients in detail.

OBJECTIVE

To provide baseline characteristics in the largest study population to date of patients with FCS.

METHODS

We analyzed baseline demographic and clinical characteristics of adult FCS patients in the phase 3 APPROACH study of volanesorsen sodium (antisense inhibitor of apolipoprotein C-III).

RESULTS

Sixty-six patients were included in the analysis. Mean (SD) age was 46 (13) years; and mean body mass index was 24.9 (5.7) kg/m². We identified causal mutations in 79% (52) of patients, with LPL mutations accounting for 62% (41) of cases. Median age at diagnosis was 24 years, 54% were females, and 81% were Caucasian. All patients followed a low-fat diet, 43% received fibrates, 27% fish oils, and 21% statins. Median fasting triglyceride levels (P25, P75) were 1985 (1179, 3047 mg/dL). Overall, 76% of patients reported ≥1 lifetime episode of acute pancreatitis; 23 patients reported a total of 53 pancreatitis events in the 5 years before enrollment.

CONCLUSIONS

Our data emphasize the severe hypertriglyceridemia characteristic of FCS patients despite restrictive low-fat diets and frequent use of existing hypolipemic therapies. Acute pancreatitis and recurrent acute pancreatitis are frequent complications of FCS. Diagnosis at an older age suggests likely underdiagnosis and underappreciation of this rare disorder.

The burden of familial chylomicronemia syndrome: Results from the global IN-FOCUS study

BACKGROUND

Familial chylomicronemia syndrome (FCS) is a rare genetic disorder characterized by a deficiency of lipoprotein lipase leading to extreme hypertriglyceridemia. Patients' burden of illness and quality of life have been poorly addressed in the literature.

OBJECTIVE

To understand the ways in which FCS impacts patients' lives.

METHODS

Investigation of Findings and Observations Captured in Burden of Illness Survey (IN-FOCUS) was a global web-based survey open to patients with FCS. Survey questions captured information on diagnostic experience, symptoms, comorbidities, disease management, and impact on multiple life dimensions.

RESULTS

Of 166 patients in 10 countries, 62% were from the United States and 70% were male. Median age at the time of the survey was 33 years, and median age at diagnosis was 9 years. Patients saw a mean of 5 physicians from different specialties before their FCS diagnosis and experienced multiple physical, emotional, and cognitive symptoms on a daily to monthly basis; 40% were admitted to the hospital in the past year. A lifetime mean of 13 episodes occurred in the 40% of patients with FCS-related acute pancreatitis. Most patients (>90%) found managing fat intake to be difficult, and 53% experienced symptoms despite adherence to their diets. FCS impacted employment status (94%), emotional/mental well-being (58%-66%), and social relationships (68%-82%).

CONCLUSIONS

Patients with FCS experience significant clinical and psychosocial burdens that reduce their quality of life and limit employment and social interactions. Increased awareness among healthcare professionals of the multifaceted nature of the FCS disease burden may help expedite diagnosis and timely institution of treatment and broaden management considerations.