The Trp-Stop and Trp-Gly mutations in the LDL receptor gene: common causes of familial hypercholesterolemia in Denmark

Mutations in the gene for the low density lipoprotein (LDL) receptor cause the autosomal dominant disease familial hypercholesterolemia (FH), the prevalence of which is about 0.2% in most populations. By PCR-SSCP analysis and direct sequencing, we identified the receptor-negative Trp²³-Stop LDL receptor mutation (FH Cincinnati-5) in 10 of 63 FH probands and the receptor-defective Trp⁶⁶-Gly LDL receptor mutation (FH French Canadian-4) in another 10 of the 63 FH probands. These two mutations thus account for 30% of diagnosed FH families in Denmark. Comparison of the mean lipid concentrations (unadjusted and adjusted for age), including serum total cholesterol and LDL-cholesterol, showed no significant differences between the two groups of FH heterozygote probands (cholesterol: 10.7 mmol/l vs. 10.7 mmol/l) and between the probands and 16 and 22 non-proband family members with the Trp²³-stop (cholesterol: 10.1 mmol/l) and Trp⁶⁶-Gly (cholesterol: 10.7 mmol/l) mutations, respectively.     

Autosomal recessive hypercholesterolemia in three sisters with phenotypic homozygous familial hypercholesterolemia: diagnostic and therapeutic procedures

Familial hypercholesterolemia is an autosomal-dominant inherited disorder caused by mutations in the low-density lipoprotein (LDL) receptor gene. The homozygous form is characterized by high-serum LDL cholesterol concentrations, xanthoma formation and premature atherosclerosis. Recently, another molecular defect that also results in severely elevated LDL cholesterol levels was identified: autosomal recessive hypercholesterolemia. This inherited disorder is caused by a mutation in a putative LDL receptor adaptor protein. In our lipid clinic, three sisters with phenotypic homozygous hypercholesterolemia were recently diagnosed as having autosomal recessive hypercholesterolemia. They presented in 1990 with massive tuberous xanthomas at the knees, thighs, elbows and buttocks. LDL receptor and apolipoprotein B gene defects were excluded through mutation analysis. From 1992 onward they underwent LDL-apheresis on a weekly basis. To date the clinical outcome is very satisfying with no evidence of coronary heart disease or aortic valve lesions and almost complete regression of xanthomatosis.     

姐妹2人同患家族性高胆固醇血症家系LDL-R基因突变分析

目的:对临床确诊的家族性高胆固醇血症(FH)两姐妹及其家系成员进行低密度脂蛋白受体(LDL-R)基因突变分析,探讨其发病机制。方法:提取患者外周血基因组DNA,聚合酶链反应分别扩增启动子和18个外显子片断,采用单链构象多态性(PCR-SSCP)结合银染技术,对异常电泳条带进行核苷酸序列分析。结果:姐妹2人及其父亲,叔叔,祖母均发现LDL-R基因第13外显子存在一个错义突变,与GeneBank对照证实第1879位G→A碱基置换,氨基酸的改变为丙氨酸→苏氨酸(A606T突变),其母亲和女儿经测序并未发现此突变位点。结论:姐妹2人均为LDL-R基因存在A606T杂合错义突变,并均来自其父系亲属;可能是该家系发病的分子基础。     

Spectrum of LDLR gene mutations, including a novel mutation causing familial hypercholesterolaemia, in North-western Greece

Background

Familial Hypercholesterolaemia (FH) is a clinical syndrome characterised by elevated serum low-density lipoprotein (LDL) cholesterol, by tendon xanthomata and clinical manifestations of ischaemic heart disease in early life. Typically, it results from mutations in the low-density lipoprotein receptor (LDLR) gene. Furthermore, there are 3 additional genetic disorders that cause clinical syndromes that mimic FH. These are: 1) familial ligand-defective apolipoprotein (apo)-B (FLDH), 2) familial hypercholesterolaemia type 3 (FH3) and 3) autosomal recessive hypercholesterolaemia (ARH). The aim of this study was to elaborate the impact of the above genetic disorders in Greek patients with a clinical diagnosis of FH.

Methods

In this study, we assessed the contribution of the LDLR, Apo B, ARH and PCSK9 genes in the expression of FH in North-western Greece. Two hundred and fifty-four (254) probands with a clinical diagnosis of FH were included in the study.

Results

One hundred and sixty-nine (169) patients had one of the following LDLR gene mutations: 81T>G, 1775G>A, 517T>C, 858C>A, 1352T>C, 1285G>A, 761A>C, 1195G>A, 1646G>A and a deletion mutation g.387-410del24 in exon 4. We sequenced the Apo B, ARH and PCSK9 genes in 40, randomly selected patients, from the 85 patients with no identified LDLR gene defects. In these 40, randomly selected patients, with the exception of benign single nucleotide polymorphisms, no functional mutations were identified for all the above mentioned sequenced genes.

Conclusion

Our results reveal substantial genetic heterogeneity for FH in North-western Greece with at least ten LDLR gene mutations present in the study population. One of these mutations although quite rare is reported here for the first time in the scientific literature. The detection of these mutations is important as they may be used to design multiplex detection assays for large scale population screening programmes to facilitate primary and secondary prevention of cardiovascular disease in the region. Finally, ARH, Apo B and PCSK9 gene defects were excluded from causing FH in a subgroup of the study population indicating that other yet unrecognized genes may be involved in causing the clinical feature of FH, and/or that large scale deletions/duplications evaded the applied mutation detection techniques of this study.     

Influence of LDL receptor gene mutation and apo E polymorphism on lipoprotein response to simvastatin treatment among adolescents with heterozygous familial hypercholesterolemia

The efficacy of the inhibitors of HMG CoA reductase shows considerable interindividual variation and intense research has focused in the recent years to identify the genetic loci and environmental factors responsible for this variability. A randomized, double-blind, placebo-controlled clinical trial with simvastatin, an HMG CoA reductase inhibitor, was conducted in 63 adolescents (47 treated versus 17 controls) with heterozygous FH. The patients were grouped according to known low-density lipoprotein (LDL) receptor gene mutation class. After 6 weeks of treatment with 20 mg/d of simvastatin, the mean reduction in plasma LDL-cholesterol in patients with a receptor-negative mutation (n=33) was 39% whereas, in the receptor-defective mutation group (n=14), it was 31% (P=0.01). Multiple regression analyses showed that there was a significant association between the apo E polymorphism and LDL-cholesterol response to simvastatin only among heterozygotes for a receptor-negative mutation. In subjects carrying a receptor-defective mutation, however, we observed that 51% of the variability in LDL-cholesterol response was explained by variations in the dosage of simvastatin expressed in mg/kg/day (P=0.0028). There was no significant association between LDL-cholesterol response and the dosage of simvastatin among heterozygotes for a receptor-negative mutation. The results of the present study have shown that the contribution of apo E polymorphism and the dosage of simvastatin to the LDL-cholesterol responsiveness is influenced by the nature of the LDL receptor gene mutation.     

家族性高胆固醇血症家系低密度脂蛋白受体活性及其基因突变分析

目的:对1例临床诊断为家族性高胆固醇血症(FH)纯合子患者家系进行低密度脂蛋白受体(LDL-R)活性研究及其基因突变分析,旨在探讨其分子病理机制。方法:对先证者及其父母进行血脂、颈动脉超声等检查;采用流式细胞仪检测先证者及其父母外周血淋巴细胞LDL-R表达量和功能;以先证者基因组DNA为模板,扩增载脂蛋白B100(ApoB100)基因3500区域片断,PCR产物进行核苷酸序列分析,排除由该突变导致家族性ApoB100缺陷症;用降落式PCR方法,在同一程序中分别扩增LDL-R基因的启动子和全部18个外显子片段,扩增产物进行核苷酸序列分析;发现突变后验证其父母是否存在相同基因突变。结果:先证者血清TC和LDL水平明显升高、颈动脉内中膜明显增厚;LDL-R的表达量和结合功能显著下降(分别为正常人的13.6%和21.1%);ApoB100基因3500区域未见突变,LDL-R基因第1864位碱基T取代了G发生纯合错义突变,导致第601位氨基酸天冬氨酸变成脯氨酸(D601Y)。其父母LDL-R基因发现了相同的杂合突变,经检索该突变在我国未见报道。结论:证实家系先证者存在LDL-R基因突变,分别来源于父系和母系的遗传,该突变可能是家系发病的分子基础;D601Y也可能是我国FH患者LDL-R基因一种新的突变类型。     

Association between causative mutations and response to PCSK9 inhibitor therapy in subjects with familial hypercholesterolemia: A single center real-world study

Background and aimsFamilial hypercholesterolemia (FH) is an autosomal dominant disease that leads to cardiovascular (CV) disease. Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9-I) demonstrated efficacy in low-density lipoprotein cholesterol (LDL-C) reduction and in prevention of CV events. The aim of our study is to evaluate the relationship between LDL receptor (LDLR) mutations and response to PCSK9-I therapy.Methods and resultsWe evaluated total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) in consecutive patients with FH before PCSK9-I treatment and after 12 (T12w) and 36 (T36w) weeks of treatment. We evaluated LDL-C target achievement according to different mutations in LDLR. Eighty FH subjects (mean age:54 ± 13.3 years), 39 heterozygous (He) with defective LDLR gene mutations, 30 He with null mutations and 11 compound-He or homozygous (Ho) were recruited. At baseline, 69 subjects were under maximal lipid lowering therapy (MLLT) and 11 subjects had statin-intolerance. From baseline to T36w we observed an overall 51% reduction in LDL-C. We found no difference in LDL-C changes between subjects with He-defective mutation and He-null mutations both at T12w (p = 1.00) and T36w (p = 0.538). At T36w, LDL-C target was achieved in 59% of He-defective mutations subjects and in 36% of He-null mutations subgroup (p = 0.069), whereas none of compound-He/Ho-FH achieved LDL-C target.ConclusionsAfter 36 weeks there were no differences in response to PCSK9-I therapy between different groups of He-FH subjects. Response to PCSK9-I was significantly lower in carriers of compound-He/Ho mutations.Registration number for clinical trials: NCT04313270 extension.     

LDL Apheresis in Clinical Practice: Long-Term Treatment of Severe Hyperlipidemia

Abstract: Thirty patients (13 males, 17 females) suffering from familial hypercholesterolemia resistant to diet and lipid-lowering drugs were treated for 48.7 ± 19.2 months (range, 2–87 months) with low density lipoprotein (LD-L) apheresis. Three different systems (dextran sulfate adsorption for 27 of 30 [Kaneka, Liposorber, Japan], immunoadsorption system for 2 of 30 [Baxter, Therasorb, Germany], immunoadsorption system with special lipoprotein a [Lp(a)] columns for 1 of 30 patients [Lipopak, Pocard, Russia]) were applied. Before LDL apheresis 24 of 30 patients suffered from coronary heart disease (CHD) with angina symptoms. With LDL apheresis, reductions of 46% for total cholesterol, 49% for LDL, 30% for Lp(a), and 38% for triglycerides were reached. Severe side effects such as shock or allergic reactions were very rare (0.5%). In the course of treatment, an improvement in general well-being and increased performance were experienced in 27 of 30 patients. A 60 to 100% reduction of nitrate medication was observed in 17 of 24 patients. Regarding the different apheresis systems used, at the end of the trial there were no significant differences with respect to the clinical outcome experienced by the patients and concerning total cholesterol, LDL, high density lipoprotein, and triglyceride concentrations. But to reduce high Lp(a) levels, the immunoadsorption method with special Lp(a) columns seems to be the most effective (-57% versus 25% [Kaneka] and 23% [Baxter]). The present data clearly demonstrate that treatment with LDL apheresis of patients suffering from familial hypercholesterolemia, resistant to maximum conservative therapy, is very effective and safe, even in long-term application.     

Characterization of novel mutations in the catalytic domain of the PCSK9 gene

Objectives. To expand our understanding of the structure and function of proprotein convertase subtilisin/kexin type 9 (PCSK9) by studying how naturally occurring mutations in PCSK9 disrupt the function of PCSK9. Design. Mutations in PCSK9 were identified by sequencing of DNA from subjects with hypo‐ or hypercholesterolemia. The effect of the identified mutations on the autocatalytic cleavage and secretion of PCSK9, as well as the effect on PCSK9‐mediated degradation of the low density lipoprotein receptors, were determined in HepG2 or HEK293 cells transiently transfected with mutant PCSK9‐containing plasmids. The findings were collated to the clinical characteristics of the subjects possessing these mutations, and the phenotypic effects were analysed in terms of available structural data for PCSK9. Results. Five novel mutations in PCSK9 were identified. Mutation R215H was a gain‐of‐function mutation which causes hypercholesterolemia. Mutation G236S and N354I were loss‐of‐function mutations due to failure to exit the endoplasmic reticulum or failure to undergo autocatalytic cleavage, respectively. Mutations A245T and R272Q were most likely normal genetic variants. By comparing the number of patients with gain‐of‐function mutations in PCSK9 with the number of familial hypercholesterolemia heterozygotes among subjects with hypercholesterolemia, the prevalence of subjects with gain‐of‐function mutations in PCSK9 in Norway can be estimated to one in 15 000. Conclusion. This study has provided novel information about the structural requirements for the normal function of PCSK9. However, more studies are needed to determine the mechanisms by which gain‐of‐function mutations in PCSK9 cause hypercholesterolemia.     

Severe heterozygous familial hypercholesterolemia and risk for cardiovascular disease: A study of a cohort of 14,000 mutation carriers

Background

Some recently emerged lipid-lowering therapies are currently restricted to patients with homozygous familial hypercholesterolemia (HoFH), and studies are underway to also assess these therapies in patients with ‘severe heterozygous FH (HeFH)’. However, no uniform definition of ‘severe HeFH’ exists, although untreated low-density lipoprotein cholesterol (LDL-C) levels above 8 mmol/L (309 mg/dl) have been historically used to define this phenotype. Our aim was to define severe HeFH, to establish its prevalence and CVD risk, and to study the relative contribution of classical risk factors to CVD risk in HeFH patients.

Methods and results

We analysed a cohort of 14,283 patients with molecularly defined HeFH, identified by the national FH screening programme in the Netherlands. Age and gender specific percentiles of untreated LDL-C were determined. The percentile corresponding to an LDL-C level of 8 mmol/L (309 mg/dL) in men aged 36–40 years (90^th percentile) was selected as the cut-off value for severe HeFH. By applying this percentile-criterion to the whole cohort, 11% of the HeFH patients could be considered as having severe HeFH. Combined with an estimated HeFH prevalence of 1:300 in the Netherlands, this would translate into a prevalence of approximately 1:3,000 for severe HeFH. CVD risk was significantly increased in severe HeFH patients compared to non-severe HeFH patients (adjusted hazard ratio: 1.25 [95% CI: 1.05–1.51], p = 0.015). In line, male gender, increased age, increased BMI, smoking, hypertension, diabetes, high LDL-C and low high-density lipoprotein cholesterol were independent CVD risk factors in HeFH per se.

Conclusions

We changed the commonly used static LDL-C level of 8 mmol/L for the identification of severe HeFH into an age and gender corrected percentile. This definition would theoretically result in a prevalence of 1:3,000 for severe HeFH. Patients with severe HeFH are at increased CVD risk compared to non-severe HeFH patients, which underscores the need for more aggressive LDL-C lowering these patients.     

Identification and functional characterization of LDLR mutations in familial hypercholesterolemia patients from Southern Italy

Objective

Autosomal dominant hypercholesterolemias are due to defects in the LDL receptor (LDLR) gene, in the apolipoprotein B-100 gene or in the proprotein convertase subtilisin/kexin type 9 gene. The aim of this study was to identify and functionally characterize mutations in the LDLR gene that account for most cases of familial hypercholesterolemia (FH).

Methods

We enrolled 56 unrelated patients from Southern Italy with a clinical diagnosis of FH. The mutation screening was performed by direct sequencing of the promoter and the 18 exons of the LDLR gene and by multiplex ligation-dependent probe amplification (MLPA) analysis to search for large rearrangements.

Results and conclusion

We found 5 new mutations, the causative role of which was demonstrated by functional characterization performed by quantification of fluorescent LDL uptake in EBV-transformed B lymphocytes. These results enlarge the spectrum of FH-causative LDLR mutations. Lastly, screening for large rearrangements is highly recommended for the genetic diagnosis of FH.     

Statin therapy and risk of diabetes in patients with heterozygous familial hypercholesterolemia or familial combined hyperlipidemia

Objective

Controversial findings exist regarding potential influence of statin therapy on diabetic incidence. Aim of this study was to investigate the role of long duration statin treatment on diabetes mellitus (DM) incidence of Heterozygous Familial Hypercholesterolemia (hFH) and Familial Combined Hyperlipidemia (FCH) patients.

Methods

Study population consisted of 212 hFH and 147 FCH patients that visited Lipid Outpatient Department (mean follow up of 11 and 10 years respectively). Several clinical data such as history of DM, cardiovascular disease, thyroid function, metabolic syndrome, glucose levels, lipid profile and lifestyle data were obtained. In order to compare the effects of different doses of different types of statins, a “statin treatment intensity product” was used.

Results

14% of FCH and only 1% of hFH patients developed DM during follow up. Although univariate analysis showed a statistical trend (p = 0.06) in the association between new onset DM and statin treatment intensity (STI) in the FCH subgroup of patients with normal baseline glucose levels, this was no longer significant after adjusting for several confounders. Furthermore, the type of statins used did not seem to play a role in the development of DM either in hFH or FCH patients.

Conclusion

Long duration of high STI does not seem to be associated with diabetic risk in hFH patients. High STI used in the FCH population is not associated with increased risk of new onset DM compared to low STI. Further studies are required in order to clarify the potential diabetogenic effects of statins in these high risk populations.     

家族性高胆固醇血症低密度脂蛋白受体基因突变分析

目的:检测1例家族性高胆固醇血症(FH)先证者及其4代家系成员低密度脂蛋白受体(LDL-R)基因突变,探讨该家族FH可能发病分子机制.方法:收集先证者及其家系成员临床资料和基因组DNA,以基因组DNA为模板,用PCR方法扩增LDL-R基因的启动子和全部18个外显子,PCR产物进行限制性内切酶技术结合DNA测序,核苷酸序列分析结果与Gen Bank比对寻找突变;采用PCR-DNA测序技术检测apoB100基因R3500Q、R3531C和R3500W位点以及枯草溶菌素转化酶9(PCSK9)基因,以排除家族性apoB100缺陷症和PCSK9基因突变.结果:先证者及其部分家系成员第6号外显子发生Cys276X杂合无义突变,为半胱氨酸改变为提前终止密码子,使终止密码子在第276位提前出现,为致病性突变,国内尚无报道;另外,第15号外显子发生Arg744Arg同义突变.其母未发现上述突变,未检测出患者及其家系apoB100基因R3500Q、R3531C和R3500W突变以及枯草溶菌素转化酶9基因突变.结论:此患者及家系LDL-R基因存在Cys276X无义突变,可能是FH的致病突变,该突变是我国FH患者LDLR基因的一种新突变类型.     

Analysis of steatosis biomarkers and inflammatory profile after adding on PCSK9 inhibitor treatment in familial hypercholesterolemia subjects with nonalcoholic fatty liver disease: A single lipid center real-world experience

Background and aimsNonalcoholic fatty liver disease (NAFLD) may be crucial in subjects with familial hypercholesterolemia (FH). We aimed to evaluate the effect of the inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9-i) on steatosis biomarkers such as triglyceride-glucose index (TyG) and hepatic steatosis index (HSI) and analyse the role of TG/HDL in this population before and after adding-on PCSK9-i.Methods and resultsIn this observational study, we evaluated 26 genetically confirmed FH patients with NAFLD and an LDL-C off-target despite high-intensity statins plus ezetimibe. All patients added PCSK9-i treatment and obtained biochemical analysis and TyG and HSI evaluation at baseline and after six months of PCSK9-i. No difference of steatosis biomarkers was found after adding-on PCSK9-i therapy. In a secondary analysis, we divided the study population in two groups according to TG/HDL median value: high TG/HDL group (H-TG/HDL) and low TG/HDL group (L-TG/HDL). TyG and HSI were significantly lower in the L-TG/HDL than H-TG/HDL group (for TyG 9.05 ± 0.34 vs 9.51 ± 0.32; for HSI 38.43 ± 1.35 vs 41.35 ± 1.83, p value for both < 0.05). After six months of PCSK9-i therapy, TyG and HSI were significantly reduced in the L-TG/HDL group after PCSK9-i therapy (?7.5% and ?8.4% respectively, p value for both < 0.05) and these biomarkers were lower compared to H-TG/HDL group (for TyG 8.37 ± 0.14 vs 9.19 ± 0.12; for HSI 35.19 ± 1.32 vs 39.48 ± 1.33, p value for both < 0.05).ConclusionIn conclusion, PCSK9-i therapy significantly ameliorate steatosis biomarkers in FH patients with low TG/HDL; our results appear to be consistent with a beneficial role of PCSK9-i on steatosis biomarkers in FH subjects with NAFLD.     

Spectrum of LDL receptor gene mutations in Denmark: implications for molecular diagnostic strategy in heterozygous familial hypercholesterolemia.

Heterozygous familial hypercholesterolemia (FH) is one of the most common potentially fatal single-gene diseases leading to premature coronary artery disease, but the majority of heterozygous FH patients have not been diagnosed. FH is due to mutations in the gene coding for the low-density lipoprotein (LDL) receptor, and molecular genetic diagnosis may facilitate identification of more FH subjects. The Danish spectrum of 29 different mutations, five of which account for almost half of heterozygous FH, is intermediate between that of countries such as South Africa, where three mutations cause 95% of heterozygous FH in the Afrikaners, and Germany or England, where there are many more mutations. In clinical practice, a strategy for the genetic diagnosis of heterozygous FH, tailored to the mutational spectrum of patients likely to be seen at the particular hospital/region of the country, will be more efficient than screening of the whole LDL receptor gene by techniques such as single-strand conformation polymorphism (SSCP) analysis in every heterozygous FH candidate. In Aarhus, Denmark, we have chosen to examine all heterozygous FH candidates for the five most common LDL receptor gene mutations (W23X, W66G, W556S, 313 + 1G --> A, 1846 - 1G --> A) and the apoB-3500 mutation by rapid restriction fragment analysis. Negative samples are examined for other mutations by SSCP analysis followed by DNA sequencing of the exon indicated by SSCP to contain a mutation. If no point mutation or small insertion/deletion is detected, Southern blot or Long PCR analysis is performed to look for the presence of large gene rearrangements. In conclusion, our data suggest that an efficient molecular diagnostic strategy depends on the composition of common and rare mutations in a population.     

极低密度脂蛋白及低密度脂蛋白对HepG 2细胞纤溶酶原激活物抑制物-1分泌的影响

目的观察极低密度脂蛋白(VLDL)与低密度脂蛋白(LDL)是否能刺激肝细胞纤溶酶原激活物抑制物-1(PAI-l)的分泌。方法将不同浓度的VLDL与LDL加到培养的HepG2细胞,应用酶联免疫吸附法测定细胞上清液中的PAI-1抗原,采用逆转录-多聚酶链式反应(RT-PCR)观测HepG2细胞中PAI-1mRNA的表达。结果VLDL能刺激HepG2细胞PAI-1抗原的分泌并具剂量效应关系,同时PAI-1mRNA表达增加。相反LDL则不能刺激细胞PAI-1基因的表达。结论VLDL能刺激肝细胞PAI-1基因表达,VLDL的这种作用可能参与了致动脉粥样硬化的病理过程。     

Low-density lipoprotein apheresis in children with familial hypercholesterolemia: follow-up to 21 years

Twenty-seven patients (14 girls, 13 boys) affected by familial hypercholesterolemia who had begun low-density lipoprotein (LDL) apheresis treatment before the age of 15 were studied. The median age at diagnosis was 4 years and the blood LDL cholesterol level was 704 +/- 163 mg/dL. Screening was performed for homozygous or double heterozygous mutations of the LDL cholesterol receptor gene and mutations were found in 24 of the patients. The mean age at the beginning of treatment was 8.5 years and the mean length of follow up was 12.6 years. The two main procedures used were direct adsorption of lipoproteins and dextran sulfate cellulose adsorption. Nine patients experienced anaphylactic reactions due to bradykinin and six had to have their treatment changed. The LDL cholesterol level before the session was lowered by 45 +/- 11% of the value at diagnosis. The LDL cholesterol reduction in a session was 72 +/- 10%. Tendinous xanthomas disappeared or diminished dramatically in 62% of the children. In 22 patients no cardiovascular event occurred during LDL apheresis treatment. Three had angina pectoris; two others had surgical management of aortic stenosis, but no clinical manifestations. Seven children had normal cardiovascular pictures while on treatment. Eleven had abnormalities of the aortic root or coronary arteries, which in six cases had appeared before treatment; the other five children did not undergo prior cardiac evaluation. In five children the abnormalities appeared during treatment. Based on these data, LDL-apheresis can be recommended for the treatment of homozygous familial hypercholesterolemia, even in young children, with good efficiency on biological parameters, cutaneous lesions and cardiovascular events.     

Impact of high neutrophil-to-lymphocyte ratio on the cardiovascular benefit of PCSK9 inhibitors in familial hypercholesterolemia subjects with atherosclerotic cardiovascular disease: Real-world data from two lipid units

Background and aimsNeutrophil-to-lymphocyte ratio (NLR) is a novel inflammatory biomarker strongly associated with atherosclerotic cardiovascular disease (ASCVD). Our aim was to evaluate the role of NLR on pulse wave velocity (PWV) after adding-on proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9-i) in familial hypercholesterolemia (FH) subjects with ASCVD.Methods and resultsIn this prospective observational study, we evaluated 45 FH subjects with ASCVD on high-intensity statins plus ezetimibe and with an off-target LDL-C. Study population was divided into two groups according to the mean value of NLR. All patients received PCSK9-i therapy and obtained biochemical analysis as well as PWV evaluation at baseline and after six months of PCSK9-i. After six months of add-on PCSK9-i therapy, a significant reduction of TC, LDL-C, Non-HDL-C, Lp(a) and ApoB plasma levels was observed in the two groups; while low-NLR group exhibited a significant PWV reduction after six-month therapy with PCSK9-i (Δ −16.2%, p < 0.05), no significant changes in PWV were observed in the high-NLR group.ConclusionsOnly FH subjects with low-NLR experienced a significant reduction of PWV after PCSK9-i. Our findings suggest a role of NLR in predicting PCSK9-i effect in FH subjects with ASCVD.     

Markers of atherosclerotic development in children with familial hypercholesterolemia: A literature review

Objective

Atherosclerosis is a multi-step process, where lipids, inflammatory and hemostatic mediators orchestrate plaque formation and progression, which subsequently may lead to myocardial infarction and ischemic stroke. Familial hypercholesterolemia (FH) is associated with increased risk of premature atherosclerosis due to the genetically determined elevated low density lipoprotein (LDL)-cholesterol seen in these individuals. Children with FH are suitable to investigate the isolated effect of elevated LDL-cholesterol on early markers of atherosclerosis. The aim of the present paper was to review the literature to summarize the findings of atherosclerotic markers in children with FH to better understand how elevated LDL-cholesterol per se promotes atherogenesis.

Methods

We conducted a systematic literature search from the years 1990–2013, resulting in identification of 903 articles. In order to investigate whether intima-media thickness (IMT) is different in children with and without FH, we conducted a meta-analysis of the studies comparing FH children with a control group.

Results

37 original articles were included. Among these, 24 reported subclinical measurements, whereas other articles reported measurements of atherogenic lipids (n = 9), inflammatory markers (n = 10), hemostatic markers (n = 6) and other surrogate markers of atherosclerosis (n = 7). In the meta-analysis (n = 8), IMT was significantly thicker in children with FH than in control children (weighted mean difference 0.06, 95% confidence interval [0.01, 0.11]).

Conclusion

Elevated LDL-cholesterol distinguishes children with and without FH, but these groups of children also differ in several other ways. In particular, children with FH display a variety of changes reflecting both the lipid and the inflammatory arm of atherosclerosis. The IMT-meta-analysis result strengthens the evidence of early atherosclerotic development in children with FH. In a clinical perspective, early diagnosing and treatment of children with FH is of high importance to attenuate development of the potential ongoing early atherosclerotic process in these individuals.