Consensus document on diagnosis and management of familial hypercholesterolemia from the Italian Society for the Study of Atherosclerosis (SISA).

AIMS: Familial Hypercholesterolemia (FH) is a genetic disorder of lipoprotein metabolism that causes an increased risk of premature atherosclerotic cardiovascular disease (ASCVD). Although early diagnosis and treatment of FH can significantly improve the cardiovascular prognosis, this disorder is underdiagnosed and undertreated. For these reasons the Italian Society for the Study of Atherosclerosis (SISA) assembled a Consensus Panel with the task to provide guidelines for FH diagnosis and treatment. DATA SYNTHESIS: Our guidelines include: i) an overview of the genetic complexity of FH and the role of candidate genes involved in LDL metabolism; ii) the prevalence of FH in the population; iii) the clinical criteria adopted for the diagnosis of FH; iv) the screening for ASCVD and the role of cardiovascular imaging techniques; v) the role of molecular diagnosis in establishing the genetic bases of the disorder; vi) the current therapeutic options in both heterozygous and homozygous FH. Treatment strategies and targets are currently based on low-density lipoprotein cholesterol (LDL-C) levels, as the prognosis of FH largely depends on the magnitude of LDL-C reduction achieved by lipid-lowering therapies. Statins with or without ezetimibe are the mainstay of treatment. Addition of novel medications like PCSK9 inhibitors, ANGPTL3 inhibitors or lomitapide in homozygous FH results in a further reduction of LDL-C levels. LDL apheresis is indicated in FH patients with inadequate response to cholesterol-lowering therapies. CONCLUSION: FH is a common, treatable genetic disorder and, although our understanding of this disease has improved, many challenges still remain with regard to its identification and management.

Erdheim-Chester disease as complex clinical presentation and diagnosis: A case report and concise review of literature.

RATIONALE: Erdheim-Chester disease (ECD) is a rare multisystemic disease characterized by the infiltration of multiple organs by foamy CD68 + CD1a-histiocytes. The genetic background consists of gain-of-function somatic mutations in the mitogen-activated protein kinase pathway. The purpose of the present paper is to make a contribution to the scientific literature on ECD by reporting our experience with a complex clinical case report, along with a concise review of the literature. We discussed the unusual clinical presentation, the complex diagnostic process and the comparison with other published cases. PATIENT CONCERNS: A 70-year-old man presented with arthralgia due to multiple bone areas of sclerosis, first diagnosed with metastases of a prostatic neoplasm. Sequential thorax-abdomen, femoral and homer contrast-enhanced computed tomography (CT) showed pericardial effusion, pulmonary fibrosis, and perirenal fibrous tissue as "hairy kidneys." He underwent. Three bone biopsies were unsuccessful to reach diagnosis. DIAGNOSES: A xanthelasma biopsy showed histopathological signs compatible with ECD; genetic analysis showed the mutation BRAFV600E. INTERVENTIONS: The patient underwent targeted therapy with vemurafenib (BRAF-inhibitor), discontinued 2 weeks later due to the onset of a diffuse erythematous papular rash on the trunk and limbs. OUTCOMES: At the 1-year follow-up, there was only progression of chronic kidney disease (CKD). LESSONS: The present case report describes how ECD diagnosis could represent a challenge for clinicians, owing to its heterogeneous clinical presentation. Early diagnosis followed by prompt therapy is essential for modifying the natural history of the disease.

APOC-III: a Gatekeeper in Controlling Triglyceride Metabolism.

PURPOSE OF REVIEW: Apolipoprotein C-III (ApoC-III) is a widely known player in triglyceride metabolism, and it has been recently recognized as a polyhedric factor which may regulate several pathways beyond lipid metabolism by influencing cardiovascular, metabolic, and neurological disease risk. This review summarizes the different functions of ApoC-III and underlines the recent findings related to its multifaceted pathophysiological role. RECENT FINDINGS: The role of ApoC-III has been implicated in HDL metabolism and in the development of atherosclerosis, inflammation, and ER stress in endothelial cells. ApoC-III has been recently considered an important player in insulin resistance mechanisms, lipodystrophy, diabetic dyslipidemia, and postprandial hypertriglyceridemia (PPT). The emerging evidence of the involvement of ApoC-III in the in the pathogenesis of Alzheimer's disease open the way to further study if modification of ApoC-III level slows disease progression. Furthermore, ApoC-III is clearly linked to cardiovascular disease (CVD) risk, and progression of coronary artery disease (CAD) as well as the calcification of aortic valve and recent clinical trials has pointed out the inhibition of ApoC-III as a promising approach to manage hypertriglyceridemia and prevent CVD. Several evidences highlight the role of ApoC-III not only in triglyceride metabolism but also in several cardio-metabolic pathways. Results from recent clinical trials underline that the inhibition of ApoC-III is a promising therapeutical strategy for the management of severe hypertriglyceridemia and in CVD prevention.

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.

A subgroup analysis of the ODYSSEY APPRISE study: Safety and efficacy of alirocumab in the Italian cohort.

BACKGROUND AND AIMS: ODYSSEY APPRISE trial evaluated efficacy and safety of alirocumab in 994 patients with hypercholesterolemia and high CV risk in a real-life setting. The aim of the present report is to detail on the Italian cohort enrolled and treated in the trial. METHODS AND RESULTS: The methodology of the of the multinational, single-arm, Phase 3b open-label ODYSSEY APPRISE (Clinicaltrials.gov: NCT02476006) has been previously reported. 255 Italian patients were enrolled and treated according to the trial protocol. Overall mean exposure to alirocumab was 83.3 ± 27.7 weeks. At week 12, LDL-C decreased by 51.3 ± 23.1% and this reduction was overall maintained for the duration of the study. A similar reduction was observed in patients with and without heterozygous familial hypercholesterolemia (HeFH 50.7% ± 23.9 vs. non-FH, 53.6% ± 19.6). LDL-C was reduced below 1.8 mmol/L and/or by ≥ 50% reduction from baseline in 62% of patients overall (61% in HeFH and 67% in non-FH). Alirocumab was similarly well tolerated in the Italian cohort as in the entire study population and the more common treatment emergent adverse events (TEAEs) were influenza, myalgia and nasopharyngitis. The incidence LDL-C levels <25 mg/dl and <15 mg/dl, was 8.2% and 2.9% respectively. CONCLUSION: The efficacy and safety of alirocumab in a real-life setting, in the Italian subgroup of patients are consistent with findings in the entire study population and confirm that alirocumab is a beneficial approach to further reduce LDL-C levels in patients at high CV risk on maximally tolerated conventional lipid lowering treatment. GOV IDENTIFIER: NCT02476006.

Comparison of two polygenic risk scores to identify non-monogenic primary hypocholesterolemias in a large cohort of Italian hypocholesterolemic subjects.

BACKGROUND: Primary Hypobetalipoproteinemias (HBL) are a group of dominant and recessive monogenic genetic disorders caused by mutations in APOB, PCSK9, ANGPTL3, MTTP, Sar1b genes and characterized by plasma levels of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and apolipoprotein B (apoB) below the 5th percentile of the distribution in a given population. Mutations in the candidate genes account only for a small proportion of subjects with HBL suggesting a role for a polygenic contribution to the low cholesterol phenotype. OBJECTIVE: To explore the complex genetic architecture of HBL we compared two polygenic risk scores in order to assess the role of the polygenic burden and the differences in the clinical phenotype between monogenic and polygenic HBL; we studied a cohort of 170 subjects with primary HBL referred over a 25-year period to 2 Italian reference centers have been studied. METHODS: The genetic analyses have been based on: Sanger sequencing, in-house NGS customized panel and two scores, PRS1 and PRS2 for the polygenic burden. RESULTS: Sixty 60 (35%) and 63 (37%) subjects had a monogenic and polygenic HBL respectively. LDL-C plasma levels were significantly lower in monogenic HBL (30.87 ± 3.12 mg/dl) compared with the non-monogenic HBL (42.80 ± 2.18 mg/dl) (p<0.002) with no differences in the percentage of fatty liver. CONCLUSION: Only PRS1 is effective in detecting polygenic HBL while PRS2 does not improve the polygenic diagnosis.

Lifestyle versus ezetimibe plus lifestyle in patients with biopsy-proven non-alcoholic steatohepatitis (LISTEN): A double-blind randomised placebo-controlled trial.

BACKGROUND AND AIMS: The LISTEN trial (ClinicalTrial.gov accession: NCT01950884) is a phase IV 52 weeks double blind parallel randomized controlled trial that evaluated the effect of ezetimibe plus lifestyle and dietary intervention (eze) vs. lifestyle and dietary intervention alone (placebo) on progression and complications of non-alcoholic steatohepatitis (NASH) evaluated by liver histology. METHODS AND RESULTS: Forty patients with NASH ascertained by histology were randomly allocated on the two study groups and subjected to a follow-up of 52 weeks, when they underwent a second liver biopsy. Main composite end point (EP) was based on the histological improvement in the severity of NASH. Thirty patients completed the study, Eze treatment was not able to improve the primary EP in comparison with placebo, with and odds ratio of 1.029 (0.18-6.38), p = 0.974. Treatment emergent adverse events registered during the study were not more prevalent in the treatment arm. CONCLUSIONS: ezetimibe administered on top of lifestyle and dietary modification failed to improve the histology of NASH in comparison with lifestyle and dietary modification alone. TRIAL ACCESSION NUMBER: ClinicalTrial.gov: NCT01950884.

Diagnosis of familial hypercholesterolemia in a large cohort of Italian genotyped hypercholesterolemic patients.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is the most relevant genetic cause of early cardiovascular disease (CVD). FH is suspected when low density lipoprotein cholesterol (LDL-C) levels exceed the 95th percentile of the population distribution. Different diagnostic scoring systems have been developed, as the Dutch Lipid Clinic Network (DLCN) score, used worldwide. The aim of the study is to describe the characteristics of FH patients of a large cohort of more than eight hundred genotyped subjects enrolled in an Italian Lipid Clinic, and evaluate the DLCN score performance applied retrospectively to the case study. METHODS: 836 hypercholesterolemic patients with LDL-C > 4.88 mmol/L were genotyped for FH causative gene variants in the LDLR, PCSK and APOB genes. Relatives of mutated patients were also analyzed by cascade screening. RESULTS: Gene variant carriers were younger, presented higher LDL-C and DLCN score and lower HDL-C levels in comparison with hypercholesterolemic (HC) non-carriers and presented a five-fold higher prevalence of previous CV events. Carotid US data available in 490 subjects showed that variant carriers had an odds ratio of 3.66 (1.43-10.24) for atherosclerotic plaques in comparison with non-carriers. Scoring system were evaluated by ROC analysis in 203 subjects without missing DLCN items and with available pre-therapy LDL-C levels, and LDL-C levels (A.U.C. = 0.737) resulted to be more performing than the DLCN score (A.U.C. = 0.662), even including carotid US data (A.U.C. = 0.641) in a modified DLCN score version. CONCLUSIONS: the DLCN score failed to demonstrate a clear superiority in predicting FH gene variants in comparison with the measure of LDL-C levels in a retrospective case study.

Circulating Molecular Chaperones in Subjects with Amnestic Mild Cognitive Impairment and Alzheimer's Disease: Data from the Zabùt Aging Project.

Molecular chaperones play essential roles in many processes such as cell differentiation, tissue homeostasis, and organ remodeling. Recent data indicate that chaperones can act as cytoprotectants for brain cells during the progression of neurodegenerative diseases, including Alzheimer's disease (AD). However, very few data on the levels of chaperones in dementia, including its prodromal phases, have been reported. In this study, we used biological samples and epidemiological data collected during the Zabùt Aging Project (a prospective, community-based, cohort study of normal/pathological aging conducted in Sicily, Italy, with a follow-up of ten years) to determine if there is an association between plasma levels of the chaperones Hsp60, Hsp70, and Hsp90 with amnestic mild cognitive impairment (aMCI) and AD. Twenty-six aMCI individuals, 26 AD and 26 controls, matched for age and sex, were enrolled. After adjustment for education, subjects with AD showed significantly higher levels of Hsp60 than aMCI (OR = 1.16, 95% CI 1.04-1.30) and controls (OR = 1.12, 95% CI 1.03-1.22), while Hsp70 was significantly higher only in AD (OR = 1.84, 95% CI 1.09-3.10) than controls. In contrast, circulating levels of Hsp90 were significantly diminished in aMCI (OR = 0.69, 95% CI 0.52-0.91) and AD (OR = 0.51, 95% CI 0.35-0.75) compared to controls. However, these results were no longer significant after adjustment for multiple comparisons. Although the results lost significance after adjustment for multiple comparisons, they are encouraging despite the smallness of the sample and new studies should be carried out with larger populations to determine to what extent sequential measurement of serum chaperones in aMCI and AD can be trusted as indicators of disease status and progression.

Lack of phenotypic additive effect of familial defective apolipoprotein B3531 in familial hypercholesterolaemia.

Familial defective apolipoprotein (apo) B (FDB) and familial hypercholesterolaemia (FH) are the two common genetic conditions that cause hypercholesterolaemia. R3531C mutation of the APOB gene is a rare cause of FDB. Individuals with both FDB and FH are rare. A 51-year-old man with hypercholesterolaemia (11.4 mmol/L) and his family were studied. Low-density lipoprotein (LDL) receptor (LDLR) and APOB genes were analysed by direct sequencing. LDL of four subjects were studied in a fibroblast LDL receptor-binding displacement assay. We found a mutation of the LDLR gene (p.Y398X) in the proband and in four other family members: the p.R3531C APOB gene mutation was also found in the proband, his father and his children. The proband and his son were thus compound heterozygotes for both FH and FDB. Double heterozygotes did not show higher cholesterol levels compared to carriers of LDLR gene mutation alone. LDL from one of the carriers of the p.R3531C alone exhibited a binding ability, which was similar to a normal subject. This is the first report in Italy of the p.R3531C mutation, and our results show that this mutation has no effect in LDLR p.Y398X/APOB p.R3531C double heterozygotes.

rs629301 CELSR2 polymorphism confers a ten-year equivalent risk of critical stenosis assessed by coronary angiography.

BACKGROUND AND AIMS: Novel genetic determinants associated with coronary artery disease (CAD) have been discovered by genome wide association studies. Variants encompassing the CELSR2- PSRC1-SORT1 gene cluster have been associated with CAD. This study is aimed to investigate the rs629301 polymorphism association with the extent of CAD evaluated by coronary angiography (CAG), and to evaluate its associations with an extensive panel of lipid and lipoprotein measurements in a large Italian cohort of 2429 patients. METHODS AND RESULTS: The patients were collected by four Intensive Care Units located in Palermo and Verona (Italy). Clinical Records were filed, blood samples were collected, lipids and apolipoproteins (apo) were measured in separate laboratories. CAD was defined by the presence of stenotic arteries (>50% lumen diameter) by CAG. The presence of CAD was associated with the rs629301 genotype. Patients with CAD were 78% and 73% (p = 0.007) of the T/T vs. T/G + G/G genotype carriers respectively. T/T genotype was also correlated with the number of stenotic arteries, with a 1.29 (1.04-1.61) risk to have a three-arteries disease. T/T genotype correlated with higher levels of LDL-, non-HDL cholesterol, apoB, apoE and apoCIII, and lower HDL-cholesterol. Logistic Regression confirmed that rs629301was associated with CAD independently from the common risk factors, with a risk similar to that conferred by ten years of age [odds ratios were 1.43 (1.04-1.96) and 1.39 (1.22-1.58) respectively]. CONCLUSIONS: rs629301 risk allele was independently associated with the extension and severity of CAD and positively with apoE and apoB containing lipoproteins.

DeepSRE: Identification of sterol responsive elements and nuclear transcription factors Y proximity in human DNA by Convolutional Neural Network analysis.

SREBP1 and 2, are cholesterol sensors able to modulate cholesterol-related gene expression responses. SREBPs binding sites are characterized by the presence of multiple target sequences as SRE, NFY and SP1, that can be arranged differently in different genes, so that it is not easy to identify the binding site on the basis of direct DNA sequence analysis. This paper presents a complete workflow based on a one-dimensional Convolutional Neural Network (CNN) model able to detect putative SREBPs binding sites irrespective of target elements arrangements. The strategy is based on the recognition of SRE linked (less than 250 bp) to NFY sequences according to chromosomal localization derived from TF Immunoprecipitation (TF ChIP) experiments. The CNN is trained with several 100 bp sequences containing both SRE and NF-Y. Once trained, the model is used to predict the presence of SRE-NFY in the first 500 bp of all the known gene promoters. Finally, genes are grouped according to biological process and the processes enriched in genes containing SRE-NFY in their promoters are analyzed in details. This workflow allowed to identify biological processes enriched in SRE containing genes not directly linked to cholesterol metabolism and possible novel DNA patterns able to fill in for missing classical SRE sequences.

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.

NPC1L1 and ABCG5/8 induction explain synergistic fecal cholesterol excretion in ob/ob mice co-treated with PPAR-α and LXR agonists.

Reverse cholesterol transport (RCT) and transintestinal cholesterol efflux (TICE) are two important pathways for body cholesterol elimination. We studied these pathways in an animal model of diabetes and obesity (ob/ob) where HDL function is compromised as a result of hyperglycemia, low-grade inflammation and oxidative stress. Co-treatment of ob/ob mice with PPAR-α (fenofibrate) and LXR (T0901317) agonists increased fecal cholesterol by 12-fold; PPAR-α and LXR agonists individually showed 2.6- and 4.0-fold fecal cholesterol excretion, respectively. We investigated the mechanism of synergistic efficacy of PPAR-α and LXR agonists in fecal cholesterol excretion. LXR agonist and the combination of PPAR-α and LXR agonists had greater HDL-C elevation. Ex vivo cholesterol efflux showed correlation with the fecal cholesterol excretion but was not sufficient to explain 12-fold increases in the fecal cholesterol in the co-treated mice. Therefore, we examined TICE to explain the 12-fold increases in the fecal cholesterol. A strong positive correlation of fecal cholesterol with ATP binding cassette transporter G5 (ABCG5) and G8 and a negative correlation with NPC1L1 was observed. ABCG5, G8 and NPC1L1 are involved in intestinal cholesterol absorption. The extent of influence of PPAR-α and LXR agonists on RCT and TICE was distinctly different. PPAR-α agonist increased fecal cholesterol primarily by influencing TICE, while LXR agonist influenced fecal cholesterol excretion via both RCT and TICE mechanisms. Synergistic efficacy on fecal cholesterol excretion following co-treatment with PPAR-α and LXR agonists occurred through a combination of RCT, TICE, and the key enzyme in bile synthesis, cholesterol 7-α hydroxylase (cyp7a1). These results suggest that cholesterol efflux, biliary cholesterol excretion, and TICE collectively contributed to the 12-fold increases in the fecal cholesterol excretion in ob/ob mice co-treated with PPAR-α and LXR agonists.

Rapid degradation of ABCA1 protein following cAMP withdrawal and treatment with PKA inhibitor suggests ABCA1 is a short-lived protein primarily regulated at the transcriptional level.

OBJECTIVES: ATP-binding cassette transporter A1 (ABCA1) is a key player in the reverse cholesterol transport (RCT) and HDL biogenesis. Since RCT is compromised as a result of ABCA1 dysfunction in diabetic state, the objective of this study was to investigate the regulation of ABCA1 in a stably transfected 293 cells expressing ABCA1 under the control of cAMP response element. METHODS: To delineate transcriptional and posttranscriptional regulation of ABCA1, 293 cells were stably transfected with the full length ABCA1 cDNA under the control of CMV promoter harboring cAMP response element. cAMP-mediated regulation of ABCA1 and cholesterol efflux were studied in the presence of 8-Br-cAMP and after withdrawal of 8-Br-cAMP. The mechanism of cAMP-mediated transcriptional induction of the ABCA1 gene was studied in protein kinase A (PKA) inhibitors-treated cells. RESULTS: The transfected 293 cells expressed high levels of ABCA1, while non-transfected wild-type 293 cells showed very low levels of ABCA1. Treatments of transfected cells with 8-Br-cAMP increased ABCA1 protein by 10-fold and mRNA by 20-fold. Cholesterol efflux also increased in parallel. Withdrawal of 8-Br-cAMP caused time-dependent rapid diminution of ABCA1 protein and mRNA, suggesting ABCA1 regulation at the transcriptional level. Treatment with PKA inhibitors abolished the cAMP-mediated induction of the ABCA1 mRNA and protein, resulting dampening of ABCA1-dependent cholesterol efflux. CONCLUSIONS: These results demonstrate that transfected cell line mimics cAMP response similar to normal cells with natural ABCA1 promoter and suggest that ABCA1 is a short-lived protein primarily regulated at the transcriptional level to maintain cellular cholesterol homeostasis.

Therapeutic Options for Homozygous Familial Hypercholesterolemia: The Role of Lomitapide.

BACKGROUND: Lomitapide (Juxtapid® in US and Lojuxta® in Europe) is the first developed inhibitor of the Microsomal Triglyceride Transfer Protein (MTP) approved as a novel drug for the management of Homozygous Familial Hypercholesterolemia (HoFH). It acts by binding directly and selectively to MTP thus decreasing the assembly and secretion of the apo-B containing lipoproteins both in the liver and in the intestine. AIMS: The present review aims at summarizing the recent knowledge on lomitapide in the management of HoFH. RESULTS: The efficacy and safety of lomitapide have been evaluated in several trials and it has been shown a reduction of the plasma levels of Low-Density Lipoprotein Cholesterol (LDL-C) by an average of more than 50%. Although the most common side effects are gastrointestinal and liver events, lomitapide presents generally with a good tolerability and satisfactory patients compliance. Recently, in Europe, to evaluate the long-term safety and efficacy of lomitapide, the LOWER registry (ClinicalTrials.gov Identifier: NCT02135705) has been established in order to acquire informations on HoFH lomitapidetreated patients from "real life" clinical practice. Furthermore, the observation that lomitapide decreases triglyceride levels may be considered for patients affected by severe forms of hypertriglyceridemia who undergo recurrent episodes of pancreatitis and are poor responders to conventional treatment. CONCLUSION: Lomitapide represents an innovative and efficacious drug for the treatment of HoFH. Longterm safety data, treatment of pediatric and pregnant HoFH patients and management of severe hypertriglyceridemia still require further investigations.

PCSK9-D374Y mediated LDL-R degradation can be functionally inhibited by EGF-A and truncated EGF-A peptides: An in vitro study.

BACKGROUND AND AIMS: Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to low density lipoprotein receptor (LDLR) through the LDLR epidermal growth factor-like repeat A (EGF-A) domain and induces receptor internalization and degradation. PCSK9 has emerged as a novel therapeutic target for hypercholesterolemia. Clinical studies with PCSK9 inhibiting antibodies have demonstrated strong LDL-c lowering effects, but other therapeutic approaches using small molecule inhibitors for targeting PCSK9 functions may offer supplementary therapeutic options. The aim of our study was to evaluate the effect of synthetic EGF-A analogs on mutated (D374Y) PCSK9-D374Y mediated LDLR degradation in vitro. METHODS: Huh7 human hepatoma cells were transiently transfected to overexpress the gain-of-function D374Y PCSK9 mutation, which has been associated with severe hypercholesterolemia in humans. RESULTS: Transient transfection of cells with PCSK9-D374Y expression vector very effectively enhanced degradation of mature LDLR in Huh7. Treatment with both EGF-A and EGF-A truncated peptides inhibited this effect and showed increased LDLR protein in Huh7 cells transfected with PCSK9-D374Y in a clear concentration dependent manner. Huh7 transfected cells treated with increasing concentration of EGF-A analogs also showed an increase internalization of labeled Dil-LDL. CONCLUSIONS: The result of our study shows that EGF-A analogs are able to effectively hamper the enhanced degradation of LDLR in liver cells expressing PCSK9-D374Y.