Contemporary lipid-lowering management and risk of cardiovascular events in homozygous familial hypercholesterolaemia: insights from the Italian LIPIGEN Registry.

AIMS: The availability of novel lipid-lowering therapies (LLTs) has remarkably changed the clinical management of homozygous familial hypercholesterolaemia (HoFH). The impact of these advances was evaluated in a cohort of 139 HoFH patients followed in a real-world clinical setting. METHODS AND RESULTS: The clinical characteristics of 139 HoFH patients, along with information about LLTs and low-density lipoprotein cholesterol (LDL-C) levels at baseline and after a median follow-up of 5 years, were retrospectively retrieved from the records of patients enrolled in the LIPid transport disorders Italian GEnetic Network-Familial Hypercholesterolaemia (LIPIGEN-FH) Registry. The annual rates of major atherosclerotic cardiovascular events (MACE-plus) during follow-up were compared before and after baseline. Additionally, the lifelong survival free from MACE-plus was compared with that of the historical LIPIGEN HoFH cohort. At baseline, LDL-C level was 332 ± 138 mg/dL. During follow-up, the potency of LLTs was enhanced and, at the last visit, 15.8% of patients were taking quadruple therapy. Consistently, LDL-C decreased to an average value of 124 mg/dL corresponding to a 58.3% reduction (Pt < 0.001), with the lowest value (∼90 mg/dL) reached in patients receiving proprotein convertase subtilisin/kexin type 9 inhibitors and lomitapide and/or evinacumab as add-on therapies. The average annual MACE-plus rate in the 5-year follow-up was significantly lower than that observed during the 5 years before baseline visit (21.7 vs. 56.5 per 1000 patients/year; P = 0.0016). CONCLUSION: Our findings indicate that the combination of novel and conventional LLTs significantly improved LDL-C control with a signal of better cardiovascular prognosis in HoFH patients. Overall, these results advocate the use of intensive, multidrug LLTs to effectively manage HoFH.

Contemporary real-world data from the Italian cohort of patients affected by homozygous familial hypercholesterolaemia demonstrated that the addition of novel, low-density lipoprotein receptor (LDLR)-independent medications to conventional therapies allowed the achievement of unprecedented low-density lipoprotein cholesterol (LDL-C) values with a trend towards a reduction of cardiovascular risk.

Lipoprotein(a) Genotype Influences the Clinical Diagnosis of Familial Hypercholesterolemia.

Background Evidence suggests that LPA risk genotypes are a possible contributor to the clinical diagnosis of familial hypercholesterolemia (FH). This study aimed at determining the prevalence of LPA risk variants in adult individuals with FH enrolled in the Italian LIPIGEN (Lipid Transport Disorders Italian Genetic Network) study, with (FH/M+) or without (FH/M-) a causative genetic variant. Methods and Results An lp(a) [lipoprotein(a)] genetic score was calculated by summing the number risk-increasing alleles inherited at rs3798220 and rs10455872 variants. Overall, in the 4.6% of 1695 patients with clinically diagnosed FH, the phenotype was not explained by a monogenic or polygenic cause but by genotype associated with high lp(a) levels. Among 765 subjects with FH/M- and 930 subjects with FH/M+, 133 (17.4%) and 95 (10.2%) were characterized by 1 copy of either rs10455872 or rs3798220 or 2 copies of either rs10455872 or rs3798220 (lp(a) score ≥1). Subjects with FH/M- also had lower mean levels of pretreatment low-density lipoprotein cholesterol than individuals with FH/M+ (t test for difference in means between FH/M- and FH/M+ groups <0.0001); however, subjects with FH/M- and lp(a) score ≥1 had higher mean (SD) pretreatment low-density lipoprotein cholesterol levels (223.47 [50.40] mg/dL) compared with subjects with FH/M- and lp(a) score=0 (219.38 [54.54] mg/dL for), although not statistically significant. The adjustment of low-density lipoprotein cholesterol levels based on lp(a) concentration reduced from 68% to 42% the proportion of subjects with low-density lipoprotein cholesterol level ≥190 mg/dL (or from 68% to 50%, considering a more conservative formula). Conclusions Our study supports the importance of measuring lp(a) to perform the diagnosis of FH appropriately and to exclude that the observed phenotype is driven by elevated levels of lp(a) before performing the genetic test for FH.

Corrigendum: The role of registers in increasing knowledge and improving management of children and adolescents affected by familial hypercholesterolemia: The LIPIGEN pediatric group.

[This corrects the article DOI: 10.3389/fgene.2022.912510.].

Functional Characterization of p.(Arg160Gln) PCSK9 Variant Accidentally Found in a Hypercholesterolemic Subject.

Familial hypercholesterolaemia (FH) is an autosomal dominant dyslipidaemia, characterised by elevated LDL cholesterol (LDL-C) levels in the blood. Three main genes are involved in FH diagnosis: LDL receptor (LDLr), Apolipoprotein B (APOB) and Protein convertase subtilisin/kexin type 9 (PCSK9) with genetic mutations that led to reduced plasma LDL-C clearance. To date, several PCSK9 gain-of-function (GOF) variants causing FH have been described based on their increased ability to degrade LDLr. On the other hand, mutations that reduce the activity of PCSK9 on LDLr degradation have been described as loss-of-function (LOF) variants. It is therefore important to functionally characterise PCSK9 variants in order to support the genetic diagnosis of FH. The aim of this work is to functionally characterise the p.(Arg160Gln) PCSK9 variant found in a subject suspected to have FH. Different techniques have been combined to determine efficiency of the autocatalytic cleavage, protein expression, effect of the variant on LDLr activity and affinity of the PCSK9 variant for the LDLr. Expression and processing of the p.(Arg160Gln) variant had a result similar to that of WT PCSK9. The effect of p.(Arg160Gln) PCSK9 on LDLr activity is lower than WT PCSK9, with higher values of LDL internalisation (13%) and p.(Arg160Gln) PCSK9 affinity for the LDLr is lower than WT, EC50 8.6 ± 0.8 and 25.9 ± 0.7, respectively. The p.(Arg160Gln) PCSK9 variant is a LOF PCSK9 whose loss of activity is caused by a displacement of the PCSK9 P' helix, which reduces the stability of the LDLr-PCSK9 complex.

Among biomarkers of neutrophil activity, matrix metalloproteinases 8 independently predicts remission of metabolic syndrome.

BACKGROUND AND AIMS: Inflammation due to the excess of nutrient intake plays an important role in the pathophysiology of metabolic syndrome (MetS). Here, the potential influence of neutrophils and their degranulation markers on MetS improvement upon dietary and behavioral counselling, has been investigated. Specifically, we aimed at investigating their role as potential predictors of metabolic syndrome improvements. METHODS AND RESULTS: patients with MetS (n = 127) received behavioral and dietary recommendations before follow-up at 6 months. Serum levels of matrix metalloproteinases (MMP)8, MMP9, myeloperoxidase (MPO), tissue inhibitor of MMP (TIMP)-1, TIMP-2, TIMP-3 and resistin were tested at baseline. In the whole cohort, baseline levels of proinflammatory MMP8, MMP9 and MPO increased together with the number of MetS criteria. Seventy-three (57%) patients experienced a reduction in MetS-defining criteria at follow-up. With respect to those with no improvement, such individuals showed lower weight and waist circumference at enrolment, less frequent smoking habits, higher levels of triglycerides and lower circulating MMP8. At logistic regression analysis, baseline MMP8 showed negative predictive ability (odds ratio (OR) 0.979 [0.961-0.997]; p = 0.025) against MetS improvement. Such findings hold true even when included in the backward stepwise logistic regression model confirming MMP8 as an independent predictor (OR 0.970 [0.949-0.993]; p = 0.009). Receiver operating characteristic (ROC) curve confirmed the predictive ability of MMP8 combined in a model including baseline MetS criteria and waist circumference. Bootstrap resampling analysis internally validated our findings. CONCLUSION: Improvement of MetS is independently associated with baseline low MMP-8 levels, suggesting a pivotal role for inflammation in metabolic alteration.

Efficacy of Long-Term Treatment of Autosomal Recessive Hypercholesterolemia With Lomitapide: A Subanalysis of the Pan-European Lomitapide Study.

Background and aim: Autosomal recessive hypercholesterolemia (ARH) is a rare autosomal recessive disorder of low-density lipoprotein (LDL) metabolism caused by pathogenic variants in the LDLRAP1 gene. Like homozygous familial hypercholesterolemia, ARH is resistant to conventional LDL-lowering medications and causes a high risk of atherosclerotic cardiovascular diseases (ASCVDs) and aortic valve stenosis. Lomitapide is emerging as an efficacious therapy in classical HoFH, but few data are available for ARH. Results: This is a subanalysis carried out on nine ARH patients included in the Pan-European Lomitapide Study. The age at starting lomitapide was 46 (interquartile range (IQR), 39.0-65.5) years, with a median treatment duration of 31.0 (IQR 14.0-40.5) months. At baseline, four (44.4%) patients had hypertension, one (11.1%) had diabetes mellitus, two (22.2%) were active smokers, and five (55.5%) reported ASCVD. The baseline LDL-C was 257.0 (IQR, 165.3-309.2) mg/dL. All patients were on statins plus ezetimibe, three were receiving Lipoprotein apheresis (LA), and one was also receiving proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i). The addition of lomitapide (mean dose, 10 mg) resulted in the achievement of a median on-treatment LDL-C of 101.7 mg/dL (IQR, 71.3-138.3; 60.4% reduction from baseline), with a best LDL-C value of 68.0 mg/dL (IQR, 43.7-86.7; 73.5% reduction from baseline). During follow-up, one patient stopped both PCSK9i and LA. Recurrence of ASCVD events was reported in one patient. The median on-treatment aspartate transaminase and alanine transaminase values were 31.1 (IQR, 22.6-48.3) U/L and 31.1 (IQR, 27.2-53.8) U/L, respectively. Among six ARH patients with available fibroscan examination, liver stiffness values recorded at the last visit were within the normal range (median, 4.7 KPa; IQR, 3.6-5.3 KPa). Conclusion: Lomitapide is effective and safe in ARH therapy as well as in classical HoFH.

Plasma HDL pattern, cholesterol efflux and cholesterol loading capacity of serum in carriers of a novel missense variant (Gly176Trp) of endothelial lipase.

BACKGROUND: Loss of function variants of LIPG gene encoding endothelial lipase (EL) are associated with primary hyperalphalipoproteinemia (HALP), a lipid disorder characterized by elevated plasma levels of high density lipoprotein cholesterol (HDL-C). OBJECTIVE: Aim of the study was the phenotypic and genotypic characterization of a family with primary HALP. METHODS: HDL subclasses distribution was determined by polyacrylamide gradient gel electrophoresis. Serum content of preß-HDL was assessed by (2D)-electrophoresis. Cholesterol efflux capacity (CEC) of serum mediated by ABCA1, ABCG1 or SR-BI was assessed using cells expressing these proteins. Cholesterol loading capacity (CLC) of serum was assayed using cultured human macrophages. Next generation sequencing was used for DNA analysis. Plasma EL mass was determined by ELISA. RESULTS: Three family members had elevated plasma HDL-C, apoA-I and total phospholipids, as well as a reduced content of preß-HDL. These subjects were heterozygous carriers of a novel variant of LIPG gene [c.526 G>T, p.(Gly176Trp)] found to be deleterious in silico. Plasma EL mass in carriers was lower than in controls. CEC of sera mediated by ABCA1 and ABCG1 transporters was substantially reduced in the carriers. This effect was maintained after correction for serum HDL concentration. The sera of carriers were found to have a higher CLC in cultured human macrophages than control sera. CONCLUSION: The novel p.(Gly176Trp) variant of endothelial lipase is associated with changes in HDL composition and subclass distribution as well as with functional changes affecting cholesterol efflux capacity of serum which suggest a defect in the early steps of revere cholesterol transport.

The Role of Registers in Increasing Knowledge and Improving Management of Children and Adolescents Affected by Familial Hypercholesterolemia: the LIPIGEN Pediatric Group.

Pathology registers can be a useful tool to overcome obstacles in the identification and management of familial hypercholesterolemia since childhood. In 2018, the LIPIGEN pediatric group was constituted within the Italian LIPIGEN study to focus on FH subjects under 18 years. This work aimed at discussing its recent progress and early outcomes. Demographic, biochemical, and genetic baseline characteristics were collected, with an in-depth analysis of the genetic defects. The analysis was carried out on 1,602 children and adolescents (mean age at baseline 9.9 ± 4.0 years), and almost the whole cohort underwent the genetic test (93.3%). Overall, the untreated mean value of LDL-C was 220.0 ± 97.2 mg/dl, with an increasing gradient from subjects with a negative (N = 317; mean untreated LDL-C = 159.9 ± 47.7 mg/dl), inconclusive (N = 125; mean untreated LDL-C = 166.4 ± 56.5 mg/dl), or positive (N = 1,053; mean untreated LDL-C = 246.5 ± 102.1 mg/dl) genetic diagnosis of FH. In the latter group, the LDL-C values presented a great variability based on the number and the biological impact of involved causative variants. The LIPIGEN pediatric group represents one of the largest cohorts of children with FH, allowing the deepening of the characterization of their baseline and genetic features, providing the basis for further longitudinal investigations for complete details.

Lipoprotein(a) Modulates Carotid Atherosclerosis in Metabolic Syndrome.

Background and Aim: High lipoprotein(a) [Lp(a)] is a well-established cardiovascular (CV) risk factor, but the effect of mildly elevated Lp(a) on CV health is largely unknown. Our aim was to evaluate if Lp(a) is associated with the severity of carotid atherosclerosis (CA) in the specific subset of metabolic syndrome (MetS). Patients and Methods: Subjects with diagnosed MetS and ultrasound-assessed CA were enrolled. Those patients were categorized according to the severity of CA (moderate vs. severe), and the circulating levels of Lp(a) alongside with clinical, anthropometric, and biochemical data were collected. Results: Sixty-five patients were finally included: twenty-five with moderate and forty with severe CA (all with asymptomatic disease). Intergroup comparison showed Lp(a) as the only significantly different variable [6 (2-12) mg/dl vs. 11.5 (6-29.5) mg/dl; p = 0.018]. Circulating levels of Lp(a) were also confirmed as the only variable independently associated with severity of CA at logistic regression analysis [OR 2.9 (95% CI 1.1-7.8); p = 0.040]. ROC curve analysis for Lp(a) confirmed a serum level of 10 mg/dl as the best cut-off value [AUC 0.675 (95% CI 0.548-0.786)]. Although sensitivity and specificity were suboptimal (69.0 and 70.4%, respectively)-likely due to the small sample size-this result is in line with those previously reported in the literature. Conclusion: Lp(a) is independently associated with severity of CA in the subgroup of MetS patients.

Lipoprotein(a) and family history for cardiovascular disease in paediatric patients: A new frontier in cardiovascular risk stratification. Data from the LIPIGEN paediatric group.

BACKGROUND AND AIMS: Little is known about the role of Lp(a) in the assessment of cardiovascular risk in the paediatric population. Trying to clarify the clinical relevance of Lp(a) in risk stratification, the aim of the study is to evaluate the association between Lp(a) plasma levels in children with familial hypercholesterolaemia (FH) and positive family history for premature cardiovascular disease (pCVD) in first- and second-degree relatives. METHODS: 653 Caucasian children and adolescents (334 females and 319 males), aged 2-17 years, with diagnosis of FH from a paediatric cohort included in the LIPIGEN Network, were selected. We compared family history of pCVD, lipid and genetic profile in two groups based on Lp(a) levels below or above 30 mg/dL. To determine the independent predictors of pCVD, a multivariate logistic regression was used, with all clinical characteristics and blood measurements as predictors. RESULTS: Subjects with Lp(a) > 30 mg/dl more frequently reported positive family history of pCVD compared to subjects with Lp(a)≤30 mg/dl (69.90% vs 36.66%, p < 0.0001), while did not show differences in terms of median [interquartile range] LDL-cholesterol level (153.00 [88.00 vs 164.50 [90.25] mg/dL, p = 0.3105). In the regression analysis, Lp(a) > 30 mg/dl was an independent predictor of family history of pCVD. Comparing subjects with or without family history of pCVD, we reported significant differences for Lp(a) > 30 mg/dl (46.25% vs 17.65%, p < 0.0001), FH genetic mutation (50.48% vs 40.75%, p = 0,0157), as well as for LDL-cholesterol (p = 0.0013) and total cholesterol (p = 0.0101). CONCLUSIONS: Children/adolescents with FH and Lp(a) > 30 mg/dl where more likely to have a positive family history of pCVD. Lp(a) screening in children and adolescents with FH may enhance risk assessment and help identify those subjects, children and relatives, at increased pCVD risk.

Search for familial hypercholesterolemia patients in an Italian community: A real-life retrospective study.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is a common inherited disorder of low-density lipoprotein (LDL) catabolism that causes elevated LDL-cholesterol (LDL-C) and premature atherosclerotic cardiovascular disease (ASCVD). Despite the availability of effective treatments, FH remains underdiagnosed and undertreated. The aims of the study were to identify putative FH subjects using data from laboratory and cardiology databases, genetically characterize suspected FH patients referred to the Lipid Clinic and monitor attainment of treatment goals in identified patients. METHODS AND RESULTS: We retrieved the electronic health records of 221,644 individuals referred to laboratory for routine assessment and of 583 ASCVD patients (age ≤65) who underwent percutaneous transluminal coronary angioplasty (PTCA). We monitored the lipid profiles of subjects with LDL-C ≥ 250 mg/dl identified by laboratory survey (LS-P), PTCA patients and patients from the Lipid Clinic (LC-P). The laboratory survey identified 1.46% of subjects with LDL-C ≥ 190 mg/dl and 0.08% with LDL-C ≥ 250 mg/dl. Probable/definite FH was suspected in 3% of PTCA patients. Molecularly-confirmed FH was found in 44% of LC-P subjects. Five new LDLR mutations were identified. The 50% LDL-C reduction target was achieved by 70.6% of LC-P patients. Only 18.5% of PTCA patients reached the LDL-C < 55 mg/dl target. CONCLUSION: By using a combined approach based on laboratory lipid profiles, documented ASCVD and Lipid Clinic data, we were able to identify subjects with a high probability of being FH. Attainment of LDL-C goals was largely suboptimal. Efforts are needed to improve FH detection and achievement of lipid targets.

Worldwide experience of homozygous familial hypercholesterolaemia: retrospective cohort study.

BACKGROUND: Homozygous familial hypercholesterolaemia (HoFH) is a rare inherited disorder resulting in extremely elevated low-density lipoprotein cholesterol levels and premature atherosclerotic cardiovascular disease (ASCVD). Current guidance about its management and prognosis stems from small studies, mostly from high-income countries. The objective of this study was to assess the clinical and genetic characteristics, as well as the impact, of current practice on health outcomes of HoFH patients globally. METHODS: The HoFH International Clinical Collaborators registry collected data on patients with a clinical, or genetic, or both, diagnosis of HoFH using a retrospective cohort study design. This trial is registered with ClinicalTrials.gov, NCT04815005. FINDINGS: Overall, 751 patients from 38 countries were included, with 565 (75%) reporting biallelic pathogenic variants. The median age of diagnosis was 12·0 years (IQR 5·5-27·0) years. Of the 751 patients, 389 (52%) were female and 362 (48%) were male. Race was reported for 527 patients; 338 (64%) patients were White, 121 (23%) were Asian, and 68 (13%) were Black or mixed race. The major manifestations of ASCVD or aortic stenosis were already present in 65 (9%) of patients at diagnosis of HoFH. Globally, pretreatment LDL cholesterol levels were 14·7 mmol/L (IQR 11·6-18·4). Among patients with detailed therapeutic information, 491 (92%) of 534 received statins, 342 (64%) of 534 received ezetimibe, and 243 (39%) of 621 received lipoprotein apheresis. On-treatment LDL cholesterol levels were lower in high-income countries (3·93 mmol/L, IQR 2·6-5·8) versus non-high-income countries (9·3 mmol/L, 6·7-12·7), with greater use of three or more lipid-lowering therapies (LLT; high-income 66% vs non-high-income 24%) and consequently more patients attaining guideline-recommended LDL cholesterol goals (high-income 21% vs non-high-income 3%). A first major adverse cardiovascular event occurred a decade earlier in non-high-income countries, at a median age of 24·5 years (IQR 17·0-34·5) versus 37·0 years (29·0-49·0) in high-income countries (adjusted hazard ratio 1·64, 95% CI 1·13-2·38). INTERPRETATION: Worldwide, patients with HoFH are diagnosed too late, undertreated, and at high premature ASCVD risk. Greater use of multi-LLT regimens is associated with lower LDL cholesterol levels and better outcomes. Significant global disparities exist in treatment regimens, control of LDL cholesterol levels, and cardiovascular event-free survival, which demands a critical re-evaluation of global health policy to reduce inequalities and improve outcomes for all patients with HoFH. FUNDING: Amsterdam University Medical Centers, Location Academic Medical Center; Perelman School of Medicine at the University of Pennsylvania; and European Atherosclerosis Society.

Long-term efficacy of lipoprotein apheresis and lomitapide in the treatment of homozygous familial hypercholesterolemia (HoFH): a cross-national retrospective survey.

BACKGROUND: Homozygous familial hypercholesterolemia (HoFH) is a rare life-threatening condition that represents a therapeutic challenge. The vast majority of HoFH patients fail to achieve LDL-C targets when treated with the standard protocol, which associates maximally tolerated dose of lipid-lowering medications with lipoprotein apheresis (LA). Lomitapide is an emerging therapy in HoFH, but its place in the treatment algorithm is disputed because a comparison of its long-term efficacy versus LA in reducing LDL-C burden is not available. We assessed changes in long-term LDL-C burden and goals achievement in two independent HoFH patients' cohorts, one treated with lomitapide in Italy (n = 30) and the other with LA in France (n = 29). RESULTS: The two cohorts differed significantly for genotype (p = 0.004), baseline lipid profile (p < 0.001), age of treatment initiation (p < 0.001), occurrence of cardiovascular disease (p = 0.003) as well as follow-up duration (p < 0.001). The adjunct of lomitapide to conventional lipid-lowering therapies determined an additional 58.0% reduction of last visit LDL-C levels, compared to 37.1% when LA was added (padj = 0.004). Yearly on-treatment LDL-C < 70 mg/dl and < 55 mg/dl goals were only achieved in 45.5% and 13.5% of HoFH patients treated with lomitapide. The long-term exposure to LDL-C burden was found to be higher in LA than in Lomitapide cohort (13,236.1 ± 5492.1 vs. 11,656.6 ± 4730.9 mg/dL-year respectively, padj = 0.002). A trend towards fewer total cardiovascular events was observed in the Lomitapide than in the LA cohort. CONCLUSIONS: In comparison with LA, lomitapide appears to provide a better control of LDL-C in HoFH. Further studies are needed to confirm this data and establish whether this translates into a reduction of cardiovascular risk.

Axion-Mediated Forces, CP Violation, and Left-Right Interactions.

We compute the CP-violating scalar axion coupling to nucleons in the framework of baryon chiral perturbation theory and we apply the results to the case of left-right symmetry. The correlated constraints with other CP-violating observables show that the predicted axion nucleon coupling is within the reach of present axion-mediated force experiments for M_{W_{R}} up to 1000 TeV.

Serum osteopontin predicts glycaemic profile improvement in metabolic syndrome: A pilot study.

Prediabetes is often observed in patients with Metabolic Syndrome (MetS) and might be associated with metabolic and inflammatory alterations. Here, we investigated whether the inflammatory molecule osteopontin (OPN) might have a prognostic impact in a cohort of MetS patients (n = 85) with baseline normal glycaemia or impaired fasting glucose (IFG) over one year of recommended pharmacological treatments and Mediterranean diet. Patients were then followed up for 12 months with intermediate evaluation after 6 months. At all time points, anthropometric and clinical data were recorded, alongside with haematological and biochemical profiles, including serum concentrations of OPN. As expected, Mediterranean diet improves glycaemic profile in patients with IFG. Baseline serum OPN failed to be associated with baseline anthropometric or biochemical variables. At baseline, higher levels of OPN were shown in patients with IFG as compared to normal glycaemia. Two distinct subgroups of patients in whom OPN decreased or remained stable/increased at follow-up were identified. When higher serum OPN levels were observed at baseline, greater reduction was observed at 1-year follow-up. Reduction in circulating OPN levels was associated with metabolic improvement in terms of blood pressure, LDL-c, HDL-c, and glycaemia. At both univariate and adjusted logistic regression analyses, serum OPN emerged as an independent predictor of glycaemic profile improvement at 1-year follow-up (adjOR 1.05 [1.00-1.10]; P = .041). In conclusion, pharmacological and dietetic interventions improved glycaemic profile in patients with MetS. In particular, glycaemic improvement was demonstrated in patients who also reduce circulating OPN levels. Higher OPN levels at baseline predict normalization of glycaemic profile.

Homozygous familial hypercholesterolemia in Italy: Clinical and molecular features.

BACKGROUND AND AIMS: Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder characterized by extremely elevated plasma levels of low density lipoprotein cholesterol (LDL-C) and high risk of premature atherosclerotic cardiovascular disease (ASCVD). HoFH is caused by pathogenic variants in several genes, such as LDLR, APOB and PCSK9, responsible for autosomal dominant hypercholesterolemia (ADH), and LDLRAP1 responsible for autosomal recessive hypercholesterolemia (ARH). Aim of this study was the review of the clinical and molecular features of patients with HoFH identified in Italy from 1989 to 2019. METHODS: Data were collected from lipid clinics and laboratories, which had performed molecular diagnosis in suspected HoFH. Clinical data included baseline lipid levels and ASCVD events. RESULTS: A total of 125 subjects with ADH were identified, of whom 60 were true homozygotes, 58 compound heterozygotes and 7 double heterozygotes for LDLR (likely) pathogenic variants. Compared with compound heterozygotes, true homozygotes showed a more severe lipid phenotype and more ASCVD events. ADH carriers of LDLR negative variants (R-NEG) presented with a more aggressive phenotype, as compared to carriers of LDLR defective variants (R-DEF). Kaplan-Meier analysis showed that the median age of ASCVD event-free survival was 25 years of age in R-NEG as opposed to 50 years of age in R-DEF patients. A total of 66 patients with ARH were also identified, of whom 46 were homozygotes and 20 compound heterozygotes. The phenotypic features of ARH patients were similar to those of R-DEF/ADH patients. Overall, 45% ADH patients and 33% ARH patients did not meet the classic diagnostic criteria for HoFH. CONCLUSIONS: In our cohort, the phenotypic variability of HoFH was dependent on the candidate gene involved and the functional impact of its variants on the LDL receptor pathway.

Long term follow-up of genetically confirmed patients with familial hypercholesterolemia treated with first and second-generation statins and then with PCSK9 monoclonal antibodies.

BACKGROUND AND AIMS: In Italy, the clinical and genetic characteristics of familial hypercholesterolemia (FH) have been extensively assessed in various lipid clinics, although no studies on long-term cardiovascular outcomes in heterozygous patients (He-FH) have been conducted. This study evaluated the incidence of atherosclerotic cardiovascular disease (ASCVD) in He-FH before and after a long-term period of lipid-lowering treatments to ascertain the interference of other risk factors. METHODS: A total of 294 genetically characterised He-FH subjects from 1989 to 2019 were retrospectively analysed. General characteristics, lipid profiles, ASCVD prevalence, and ultrasound carotid atherosclerosis assessment were evaluated. Primary end points were ASCVD outcomes and the percentage of patients reaching recommended LDL-C targets. RESULTS: During follow-up, despite a significant improvement in plasma lipid profiles, the ESC/EAS 2016 and 2019 recommended LDL cholesterol (LDL-C) goals were attained in only a few patients treated with anti-PCSK9 monoclonal antibodies added to the maximum tolerated oral therapy with statins plus ezetimibe. Forty-seven subjects had an ASCVD event before starting lipid-lowering therapy (LLT). During follow-up (median 13 years) on LLT, 28 patients had a first ASCVD event and 16 had recurrent ASCVD. In basal conditions and during follow-up, higher LDL-C levels were associated with increased ASCVD risk (p < 0.001). Prevention of recurrent ASCVD events was recorded with a long-term reduction of LDL-C below 100 mg/dl with statins plus ezetimibe. CONCLUSIONS: PCSK9 inhibition is the only therapeutic option to achieve LDL-C goals as recommended for He-FH and can prevent ASCVD events as reported in large clinical trials. Long-term treatment with statins and ezetimibe seems to be effective at preventing ASCVD recurrence when LDL-C is maintained below 130 and 100 mg/dL for primary and secondary prevention, respectively.

In vitro functional characterization of splicing variants of the APOB gene found in familial hypobetalipoproteinemia.

BACKGROUND: Familial hypobetalipoproteinemia type 1 (FHBL-1) is a codominant disorder characterized by greatly reduced plasma levels of total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B. Rare exonic pathogenic variants of APOB gene (nonsense variants, minute deletions/insertions and nonsynonymous variants) have been frequently reported in subjects with FHBL-1. Also, rare intronic variants of APOB located at intron/exon junctions and assumed to affect splicing have been reported. However, the pathogenicity of most of these intronic variants remains to be established. OBJECTIVE: The objective of this study was the in vitro functional characterization of six splicing variants of APOB gene identified in seven putative FHBL-1 heterozygotes. METHODS: ApoB minigenes harboring each variant were expressed in COS-1 cells and their transcripts were sequenced. RESULTS: Four novel variants (c.237+1G>A, c.818+5G>A, c.3000-1G>T, and c.3842+1G>A), predicted in silico to obliterate splice site activity, were found to generate abnormal transcripts. The abnormal transcripts were generated by the activation of cryptic splice sites or exon skipping. All these transcripts harbored a premature termination codon and were predicted to encode truncated apoBs devoid of function. The predicted translation products were: i) p.(Lys41Serfs*2) and p.(Val80Ilefs*10) for c.237+1G>A; ii) p.(Asn274*) for c.818+5G>A; iii) p.(Leu1001Alafs*10) for c.3000-1G>T, and iv) p.(Ser1281Argfs*2) for c.3842+1G>A. Two previously annotated rare variants (c.905-15C>G and c.1618-4G>A) with uncertain effect in silico were found to generate only wild-type transcripts. CONCLUSIONS: These in vitro minigene expression studies support the assignment of pathogenicity to four novel splice site variants of APOB gene found in FHBL-1.

Novel mutations of SAR1B gene in four children with chylomicron retention disease.

BACKGROUND: Intestinal lipid malabsorption, resulting from an impaired formation or secretion of chylomicrons and associated with severe hypobetalipoproteinemia (HBL), may be due to biallelic mutations in APOB (homozygous FHBL type-1), MTTP (abetalipoproteinemia), or SAR1B (chylomicron retention disease). OBJECTIVE: We investigated four children, each born from consanguineous parents, presenting with steatorrhea, malnutrition, accumulation of lipids in enterocytes, and severe hypocholesterolemia with an apparent recessive transmission. METHODS: We sequenced a panel of genes whose variants may be associated with HBL. RESULTS: Case 1, a 9-month-old male, was found to be homozygous for a SAR1B variant (c.49 C>T), predicted to encode a truncated Sar1b protein devoid of function (p.Gln17*). Case 2, a 4-year-old male, was found to be homozygous for a SAR1B missense variant [c.409 G>C, p.(Asp137His)], which affects a highly conserved residue close to the Sar1b guanosine recognition site. Case 3, a 6-year-old male, was found to be homozygous for an ∼6 kb deletion of the SAR1B gene, which eliminates exon 2; this deletion causes the loss of the ATG translation initiation codon in the SAR1B mRNA. The same homozygous mutation was found in an 11-month-old child (case 4) who was related to case 3. CONCLUSIONS: We report 4 children with intestinal lipid malabsorption were found to have chylomicron retention disease due to 3 novel variants in the SAR1B gene.

Baseline hs-CRP predicts hypertension remission in metabolic syndrome.

BACKGROUND: Inflammation, overweight and other cardiovascular risk factors might negatively impact on hypertension remission in metabolic syndrome (MetS), independently of the pharmacological treatment. Here, the potential influence of systemic inflammation (assessed by serum high-sensitivity C-reactive protein [hs-CRP]) on hypertension remission will be investigated in a cohort of hypertensive patients with MetS. MATERIAL AND METHODS: Hypertensive patients with MetS (n = 100) were enrolled, treated under current behavior/dietary/pharmacological recommendations and followed up for 12 months. All patients received medications and nutritional advice based on Mediterranean-like dietary pattern in addition to psychological and physical activity counselling. At baseline (T0), 6 (T1) and 12 (T2) months of follow-up, clinical data, haematological and biochemical profiles and serum hs-CRP were measured. RESULTS: As compared to T0, at T2 patients displayed improvements in anthropometric and metabolic profiles. At T2, the hypertension remission rate was 13.0%. Serum hs-CRP did not change overtime in the overall cohort. Surprisingly, patients who experienced hypertension remission were less treated with antihypertensive drugs, but developed a weak improvement in anthropometric measures during follow-up. The hypertension remission group had lower baseline levels of hs-CRP as compared to non-remission. Low baseline hs-CRP (<2 µg/mL, cut-off value identified by ROC curve) predicted hypertension remission, independently of antihypertensive treatment implementation, baseline systolic blood pressure and waist circumference improvement. CONCLUSIONS: Remission of hypertension in MetS is independently associated with baseline low CRP levels, which might suggest a critical role for inflammation in sustaining high blood pressure levels.