RESUMEN
Acid sphingomyelinase deficiency (ASMD) is an ultra-rare lysosomal storage disease with a broad spectrum of manifestations ranging from severe neuropathic forms to attenuated, chronic visceral forms. Manifestations of the chronic visceral subtype are variable and encompass different degrees of hepatosplenomegaly, pulmonary disease and dyslipidemia. The aim of this study was to provide insights into the natural course of adult patients with the chronic visceral subtype. Based on these insights, we proposed tentative criteria for initiation and follow-up of enzyme replacement therapy (ERT). The data of 23 adult patients were collected in a prospective study. Clinical, genetic and demographic data, plasma measurements, abdominal imaging, pulmonary imaging, pulmonary function tests and quality of life questionnaires were collected. Stability of disease based on several clinical, biochemical and radiological markers (i.e., spleen volume, platelet levels, liver volume, alanine aminotransferase [ALT] levels, diffusion capacity of the lungs for carbon monoxide [DLCO] chitotriosidase activity and lysosphingomyelin [LSM]) was assessed. Cardiovascular risk was estimated based on sex, age, smoking, systolic blood pressure and lipid profile. Quality of life was evaluated with the 36-Item Short Form Health Survey and the Health Assessment Questionnaire. Median follow-up was 6.1 years (range 1.3-19.5 years). The most common manifestations were splenomegaly (100%), decreased high-density lipoprotein cholesterol (HDL-C) plasma levels (83%), (signs of) steatosis measured with transient elastography (82%), thrombocytopenia (64%), hepatomegaly (52%) and decreased diffusion capacity (45%). The majority of markers remained stable during follow-up. Twelve patients showed progression of disease: four for spleen volume, two for liver volume, three for DLCO, seven for chitotriosidase activity and three for LSM. One patient showed progression of disease based on four markers, although this patient did not report any problems at the last visit. Cardiovascular risk was estimated and was increased in half of the patients older than 40 years. Patient-reported quality of life did not differ from the general population, but differences in median 36-Item Short Form Health Survey (SF-36) scores of patients with severe pulmonary involvement and those of patients without pulmonary involvement were observed. Tentative criteria for initiation and effect of therapy were proposed. In conclusion, the chronic visceral subtype of ASMD showed a predominantly stable disease course in this cohort. We propose that ERT should be initiated on an individual basis and only in case of progression or symptomatic disease. Collection and analysis of real world data are necessary to refine start, stop and follow-up criteria in the future.
RESUMEN
Acid sphingomyelinase deficiency (ASMD) is a rare LSD characterized by lysosomal accumulation of sphingomyelin, primarily in macrophages. With the recent availability of enzyme replacement therapy, the need for biomarkers to assess severity of disease has increased. Glycoprotein non-metastatic protein B (GPNMB) plasma levels were demonstrated to be elevated in Gaucher disease. Given the similarities between Gaucher disease and ASMD, the hypothesis was that GPNMB might be a potential biochemical marker for ASMD as well. Plasma samples of ASMD patients were analyzed and GPNMB plasma levels were compared to those of healthy volunteers. Visceral disease severity was classified as severe when splenic, hepatic and pulmonary manifestations were all present and as mild to moderate if this was not the case. Median GPNMB levels in 67 samples of 19 ASMD patients were 185 ng/ml (range 70-811 ng/ml) and were increased compared to 10 healthy controls (median 36 ng/ml, range 9-175 ng/ml, p < 0.001). Median plasma GPNMB levels of ASMD patients with mild to moderate visceral disease compared to patients with severe visceral disease differed significantly and did not overlap (respectively 109 ng/ml, range 70-304 ng/ml and 325 ng/ml, range 165-811 ng/ml, p < 0.001). Correlations with other biochemical markers of ASMD (i.e. chitotriosidase activity, CCL18 and lysosphingomyelin, respectively R = 0.28, p = 0.270; R = 0.34, p = 0.180; R = 0.39, p = 0.100) and clinical parameters (i.e. spleen volume, liver volume, diffusion capacity and forced vital capacity, respectively R = 0.59, p = 0.061, R = 0.5, p = 0.100, R = 0.065, p = 0.810, R = -0.38, p = 0.160) could not be established within this study. The results of this study suggest that GPNMB might be suitable as a biomarker of visceral disease severity in ASMD. Correlations between GPNMB and biochemical or clinical markers of ASMD and response to therapy have to be studied in a larger cohort.
Asunto(s)
Glicoproteínas de Membrana , Enfermedad de Niemann-Pick Tipo B , Humanos , Masculino , Femenino , Niño , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Glicoproteínas de Membrana/sangre , Enfermedad de Niemann-Pick Tipo B/sangre , Enfermedad de Niemann-Pick Tipo B/diagnóstico , Biomarcadores/sangre , Enfermedad de Niemann-Pick Tipo A/sangre , Enfermedad de Niemann-Pick Tipo A/diagnóstico , Gravedad del Paciente , Enfermedad de Gaucher/sangre , Enfermedad de Gaucher/diagnóstico , Estudios de Casos y ControlesRESUMEN
A broad spectrum of signs and symptoms has been attributed to primary carnitine deficiency (PCD) since its first description in 1973. Advances in diagnostic procedures have improved diagnostic accuracy and the introduction of PCD in newborn screening (NBS) programs has led to the identification of an increasing number of PCD patients, including mothers of screened newborns, who may show a different phenotype compared to clinically diagnosed patients. To elucidate the spectrum of signs and symptoms in PCD patients, we performed a structured literature review. Using a case-by-case approach, clinical characteristics, diagnostic data, and mode of patient identification were recorded. Signs and symptoms were categorized by organ involvement. In total, 166 articles were included, reporting data on 757 individual patients. In almost 20% (N = 136) of the cases, the diagnosis was based solely on low carnitine concentration which we considered an uncertain diagnosis of PCD. The remaining 621 cases had a diagnosis based on genetic and/or functional (ie, carnitine transporter activity) test results. In these 621 cases, cardiac symptoms (predominantly cardiomyopathy) were the most prevalent (23.8%). Neurological (7.1%), hepatic (8.4%), and metabolic (9.2%) symptoms occurred mainly in early childhood. Adult onset of symptoms occurred in 16 of 194 adult patients, of whom 6 (3.1%) patients suffered a severe event without any preceding symptom (five cardiac events and one coma). In conclusion, symptoms in PCD predominantly develop in early childhood. Most newborns and mothers of newborns detected through NBS remain asymptomatic. However, though rarely, severe complications do occur in both groups.
Asunto(s)
Cardiomiopatías , Hiperamonemia , Enfermedades Musculares , Cardiomiopatías/complicaciones , Cardiomiopatías/diagnóstico , Cardiomiopatías/genética , Carnitina/deficiencia , Carnitina/metabolismo , Preescolar , Humanos , Hiperamonemia/complicaciones , Hiperamonemia/diagnóstico , Hiperamonemia/genética , Recién Nacido , Enfermedades Musculares/complicaciones , Enfermedades Musculares/diagnóstico , Enfermedades Musculares/genética , Tamizaje Neonatal/métodos , Miembro 5 de la Familia 22 de Transportadores de Solutos/genéticaRESUMEN
Acid Sphingomyelinase Deficiency (ASMD), or Niemann-Pick type A/B disease, is a rare lipid storage disorder leading to accumulation of sphingomyelin and its precursors primarily in macrophages. The disease has a broad phenotypic spectrum ranging from a fatal infantile form with severe neurological involvement (the infantile neurovisceral type) to a primarily visceral form with different degrees of pulmonary, liver, spleen and skeletal involvement (the chronic visceral type). With the upcoming possibility of treatment with enzyme replacement therapy, the need for biomarkers that predict or reflect disease progression has increased. Biomarkers should be validated for their use as surrogate markers of clinically relevant endpoints. In this review, clinically important endpoints as well as biochemical and imaging markers of ASMD are discussed and potential new biomarkers are identified. We suggest as the most promising biomarkers that may function as surrogate endpoints in the future: diffusion capacity measured by spirometry, spleen volume, platelet count, low-density lipoprotein cholesterol, liver fibrosis measured with a fibroscan, lysosphingomyelin and walked distance in six minutes. Currently, no biomarkers have been validated. Several plasma markers of lipid-laden cells, fibrosis or inflammation are of high potential as biomarkers and deserve further study. Based upon current guidelines for biomarkers, recommendations for the validation process are provided.
Asunto(s)
Enfermedad de Niemann-Pick Tipo A/sangre , Enfermedad de Niemann-Pick Tipo A/diagnóstico por imagen , Enfermedad de Niemann-Pick Tipo B/sangre , Enfermedad de Niemann-Pick Tipo B/diagnóstico por imagen , Esfingolípidos/metabolismo , Biomarcadores/sangre , Biomarcadores/metabolismo , Enfermedades Óseas/inmunología , Enfermedades Óseas/metabolismo , Enfermedades Cardiovasculares/sangre , LDL-Colesterol/sangre , Humanos , Hepatopatías/sangre , Hepatopatías/diagnóstico por imagen , Hepatopatías/enzimología , Enfermedades Pulmonares/diagnóstico por imagen , Enfermedades Pulmonares/enzimología , Enfermedades Pulmonares/metabolismo , Macrófagos/enzimología , Macrófagos/inmunología , Macrófagos/metabolismo , Enfermedad de Niemann-Pick Tipo A/fisiopatología , Enfermedad de Niemann-Pick Tipo B/fisiopatología , Bazo/diagnóstico por imagen , Bazo/crecimiento & desarrollo , Bazo/patologíaRESUMEN
OBJECTIVE: Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors lower low-density lipoprotein (LDL) cholesterol in the vast majority of patients with autosomal dominant familial hypercholesterolemia. Will PCSK9 inhibition with monoclonal antibodies, in particular alirocumab, be of therapeutic value for patients with autosomal recessive hypercholesterolemia (ARH)? APPROACH AND RESULTS: Primary lymphocytes were obtained from 28 genetically characterized ARH patients and 11 controls. ARH lymphocytes treated with mevastatin were incubated with increasing doses of recombinant PCSK9 with or without saturating concentrations of alirocumab. Cell surface LDL receptor expression measured by flow cytometry and confocal microscopy was higher in ARH than in control lymphocytes. PCSK9 significantly reduced LDL receptor expression in ARH lymphocytes albeit to a lower extent than in control lymphocytes (25% versus 76%, respectively), an effect reversed by alirocumab. Fluorescent LDL cellular uptake, also measured by flow cytometry, was reduced in ARH lymphocytes compared with control lymphocytes. PCSK9 significantly lowered LDL cellular uptake in ARH lymphocytes, on average by 18%, compared with a 46% reduction observed in control lymphocytes, an effect also reversed by alirocumab. Overall, the effects of recombinant PCSK9, and hence of alirocumab, on LDL receptor expression and function were significantly less pronounced in ARH than in control cells. CONCLUSIONS: PCSK9 inhibition with alirocumab on top of statin treatment has the potential to lower LDL cholesterol in some autosomal recessive hypercholesterolemia patients.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Anticolesterolemiantes/farmacología , Hipercolesterolemia/tratamiento farmacológico , Linfocitos/efectos de los fármacos , Inhibidores de PCSK9 , Inhibidores de Serina Proteinasa/farmacología , Proteínas Adaptadoras Transductoras de Señales/genética , Adolescente , Adulto , Anticuerpos Monoclonales Humanizados , Estudios de Casos y Controles , Células Cultivadas , LDL-Colesterol/metabolismo , Quimioterapia Combinada , Femenino , Predisposición Genética a la Enfermedad , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Hipercolesterolemia/diagnóstico , Hipercolesterolemia/enzimología , Hipercolesterolemia/genética , Lovastatina/análogos & derivados , Lovastatina/farmacología , Linfocitos/enzimología , Masculino , Persona de Mediana Edad , Mutación , Fenotipo , Proproteína Convertasa 9/metabolismo , Receptores de LDL/metabolismo , Adulto Joven , Hiperlipoproteinemia Tipo IIIRESUMEN
AIMS: Homozygous autosomal dominant hypercholesterolaemia (hoADH), an orphan disease caused by mutations in low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin-kexin type 9 (PCSK9), is characterized by elevated plasma low-density lipoprotein-cholesterol (LDL-C) levels and high risk for premature cardiovascular disease (CVD). The exact prevalence of molecularly defined hoADH is unknown. Therefore, we investigated the prevalence and phenotypical characteristics of this disease in an open society, i.e. the Netherlands. METHODS AND RESULTS: The database of the nationwide ADH molecular diagnostic center was queried to identify all molecularly defined hoADH patients. Carriers of non-pathogenic mutations were excluded. Medical records were analysed for data regarding lipid levels and CVD events. Of 104,682 individuals screened for molecular defects, 49 were classified as hoADH (0.05%); 20 were true homozygotes, 25 were compound heterozygotes for LDLR mutations, and 4 were homozygous for APOB mutations. No bi-allelic PCSK9 mutation carriers were identified. Consequently, the prevalence of hoADH was estimated to be â¼1 : 300,000. Mean LDL-C levels prior to lipid-lowering treatment were 12.9 ± 5.1 mmol/L (range 4.4-21.5 mmol/L). Surprisingly, only 50% of the patients met the clinical criteria for hoADH (LDL-C >13.0 mmol/L); 29% of patients suffered from a CVD event. CONCLUSION: The prevalence of molecularly defined hoADH is much higher and the clinical phenotype is more variable than previously assumed. In light of the fact that novel therapies are, or will be registered for the treatment of hoADH patients, an uniform definition of hoADH either as a phenotypic or molecular entity is warranted in order to identify patients who are considered to be eligible for these novel agents.
Asunto(s)
Hiperlipoproteinemia Tipo II/epidemiología , Adolescente , Adulto , Anciano , Apolipoproteína B-100/genética , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/genética , Niño , Preescolar , Estudios de Cohortes , Femenino , Heterocigoto , Homocigoto , Humanos , Hiperlipoproteinemia Tipo II/genética , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Mutación/genética , Países Bajos/epidemiología , Fenotipo , Prevalencia , Pronóstico , Proproteína Convertasa 9 , Proproteína Convertasas/genética , Receptores de LDL/genética , Serina Endopeptidasas/genética , Adulto JovenRESUMEN
PURPOSE OF REVIEW: Homozygous autosomal dominant hypercholesterolemia (hoADH) is a rare genetic disorder caused by mutations in LDL receptor, apolipoprotein B, and/or proprotein convertase subtilisin-kexin type 9. Both the genetic mutations and the clinical phenotype vary largely among individual patients, but patients with hoADH are typically characterized by extremely elevated LDL-cholesterol (LDL-C) levels, and a very high-risk for premature cardiovascular disease. Current lipid-lowering therapies include bile acid sequestrants, statins, and ezetimibe. To further decrease LDL-C levels in hoADH, lipoprotein apheresis is recommended, but this therapy is not available in all countries. RECENT FINDINGS: Recently, the microsomal triglyceride transfer protein inhibitor lomitapide and the RNA antisense inhibitor of apolipoprotein B mipomersen were approved by the Food and Drug Administration/European Medicine Agency and the Food and Drug Administration, respectively. Several other LDL-C-lowering strategies and therapeutics targeting the HDL-C pathway are currently in the clinical stage of development. SUMMARY: Novel therapies have been introduced for LDL-C-lowering and innovative drug candidates for HDL-C modulation for the treatment of hoADH. Here, we review the current available literature on the prevalence, diagnosis, and therapeutic strategies for hoADH.
Asunto(s)
Hiperlipoproteinemia Tipo II/terapia , Animales , Anticolesterolemiantes/farmacología , Anticolesterolemiantes/uso terapéutico , Proteínas de Transferencia de Ésteres de Colesterol/antagonistas & inhibidores , HDL-Colesterol/administración & dosificación , Terapia Genética , Humanos , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/epidemiología , Prevalencia , Proproteína Convertasa 9 , Proproteína Convertasas/antagonistas & inhibidores , Serina EndopeptidasasRESUMEN
OBJECTIVE: Autosomal recessive hypercholesterolemia is a rare inherited disorder, characterized by extremely high total and low-density lipoprotein cholesterol levels, that has been previously linked to mutations in LDLRAP1. We identified a family with autosomal recessive hypercholesterolemia not explained by mutations in LDLRAP1 or other genes known to cause monogenic hypercholesterolemia. The aim of this study was to identify the molecular pathogenesis of autosomal recessive hypercholesterolemia in this family. APPROACH AND RESULTS: We used exome sequencing to assess all protein-coding regions of the genome in 3 family members and identified a homozygous exon 8 splice junction mutation (c.894G>A, also known as E8SJM) in LIPA that segregated with the diagnosis of hypercholesterolemia. Because homozygosity for mutations in LIPA is known to cause cholesterol ester storage disease, we performed directed follow-up phenotyping by noninvasively measuring hepatic cholesterol content. We observed abnormal hepatic accumulation of cholesterol in the homozygote individuals, supporting the diagnosis of cholesterol ester storage disease. Given previous suggestions of cardiovascular disease risk in heterozygous LIPA mutation carriers, we genotyped E8SJM in >27 000 individuals and found no association with plasma lipid levels or risk of myocardial infarction, confirming a true recessive mode of inheritance. CONCLUSIONS: By integrating observations from Mendelian and population genetics along with directed clinical phenotyping, we diagnosed clinically unapparent cholesterol ester storage disease in the affected individuals from this kindred and addressed an outstanding question about risk of cardiovascular disease in LIPA E8SJM heterozygous carriers.
Asunto(s)
Enfermedad de Acumulación de Colesterol Éster/genética , Análisis Mutacional de ADN , Exoma , Pruebas Genéticas/métodos , Hipercolesterolemia/genética , Mutación , Esterol Esterasa/genética , Adulto , Biomarcadores/sangre , Colesterol/sangre , Enfermedad de Acumulación de Colesterol Éster/sangre , Enfermedad de Acumulación de Colesterol Éster/diagnóstico , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Femenino , Predisposición Genética a la Enfermedad , Herencia , Homocigoto , Humanos , Hipercolesterolemia/sangre , Hipercolesterolemia/diagnóstico , Modelos Lineales , Hígado/metabolismo , Masculino , Persona de Mediana Edad , Linaje , Fenotipo , Valor Predictivo de las Pruebas , Análisis de Componente Principal , Triglicéridos/sangre , Adulto Joven , Hiperlipoproteinemia Tipo IIIRESUMEN
PURPOSE OF REVIEW: Mipomersen has been approved by the US Food and Drug Administration as an orphan drug for patients with homozygous familial hypercholesterolemia (HoFH). In contrast, the European Medicines Agency advised negatively on the use of mipomersen. In this review, we discuss the efficacy and safety considerations for this discrepancy. RECENT FINDINGS: On the basis of the results of clinical trials with mipomersen, safety concerns have been raised regarding cardiovascular risk reduction and development of hepatic steatosis. In addition, (long-term) tolerability concerns have been raised predominantly regarding injection site reactions. A pooled analysis of cardiovascular events in phase III trials with mipomersen did not provide evidence for either a positive or negative effect on cardiovascular disease. Although long-term studies with mipomersen are eagerly awaited, hepatic fat content appears to stabilize after 6-12 months notwithstanding continued mipomersen administration. SUMMARY: HoFH is a disease with an unmet medical need for new lipid-lowering therapies. On the basis of a mean 2.9âmmol/l LDL-cholesterol reduction, mipomersen is expected to reduce cardiovascular risk in HoFH. Available evidence suggests that the fat accumulation associated with this treatment differs from steatohepatitis, which is a progressive and damaging liver disease. No evidence is available suggesting that injection site reactions because of mipomersen treatment will result in safety issues.
Asunto(s)
Anticolesterolemiantes/uso terapéutico , Hiperlipoproteinemia Tipo II/tratamiento farmacológico , Oligonucleótidos/uso terapéutico , Animales , Anticolesterolemiantes/efectos adversos , Anticolesterolemiantes/farmacología , LDL-Colesterol/sangre , Ensayos Clínicos Fase III como Asunto , Aprobación de Drogas , Europa (Continente) , Hígado Graso/inducido químicamente , Humanos , Hiperlipoproteinemia Tipo II/sangre , Hígado/efectos de los fármacos , Hígado/metabolismo , Metaanálisis como Asunto , Oligonucleótidos/efectos adversos , Oligonucleótidos/farmacología , Estados UnidosRESUMEN
OBJECTIVE: Although the association between circulating levels of lipoprotein(a) [Lp(a)] and risk of coronary artery disease (CAD) and stroke is well established, its role in risk of peripheral arterial disease (PAD) remains unclear. Here, we examine the association between Lp(a) levels and PAD in a large prospective cohort. To contextualize these findings, we also examined the association between Lp(a) levels and risk of stroke and CAD and studied the role of low-density lipoprotein as an effect modifier of Lp(a)-associated cardiovascular risk. METHODS AND RESULTS: Lp(a) levels were measured in apparently healthy participants in the European Prospective Investigation of Cancer (EPIC)-Norfolk cohort. Cox regression was used to quantify the association between Lp(a) levels and risk of PAD, stroke, and CAD outcomes. During 212 981 person-years at risk, a total of 2365 CAD, 284 ischemic stroke, and 596 PAD events occurred in 18 720 participants. Lp(a) was associated with PAD and CAD outcomes but not with ischemic stroke (hazard ratio per 2.7-fold increase in Lp(a) of 1.37, 95% CI 1.25-1.50, 1.13, 95% CI 1.04-1.22 and 0.91, 95% CI 0.79-1.03, respectively). Low-density lipoprotein cholesterol levels did not modify these associations. CONCLUSIONS: Lp(a) levels were associated with future PAD and CAD events. The association between Lp(a) and cardiovascular disease was not modified by low-density lipoprotein cholesterol levels.
Asunto(s)
Trastornos Cerebrovasculares/epidemiología , Enfermedad de la Arteria Coronaria/epidemiología , Lipoproteína(a)/sangre , Enfermedad Arterial Periférica/epidemiología , Accidente Cerebrovascular/epidemiología , Adulto , Anciano , Biomarcadores/sangre , Trastornos Cerebrovasculares/sangre , Estudios de Cohortes , Enfermedad de la Arteria Coronaria/sangre , Europa (Continente) , Femenino , Humanos , Lipoproteínas LDL/sangre , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/sangre , Estudios Prospectivos , Análisis de Regresión , Factores de Riesgo , Accidente Cerebrovascular/sangre , Reino UnidoRESUMEN
BACKGROUND: Acid Sphingomyelinase Deficiency (ASMD) is a rare autosomal recessive disorder caused by mutations in the SMPD1 gene. This rarity contributes to misdiagnosis, delayed diagnosis and barriers to good care. There are no published national or international consensus guidelines for the diagnosis and management of patients with ASMD. For these reasons, we have developed clinical guidelines that defines standard of care for ASMD patients. METHODS: The information contained in these guidelines was obtained through a systematic literature review and the experiences of the authors in their care of patients with ASMD. We adopted the Appraisal of Guidelines for Research and Evaluation (AGREE II) system as method of choice for the guideline development process. RESULTS: The clinical spectrum of ASMD, although a continuum, varies substantially with subtypes ranging from a fatal infantile neurovisceral disorder to an adult-onset chronic visceral disease. We produced 39 conclusive statements and scored them according to level of evidence, strengths of recommendations and expert opinions. In addition, these guidelines have identified knowledge gaps that must be filled by future research. CONCLUSION: These guidelines can inform care providers, care funders, patients and their carers about best clinical practice and leads to a step change in the quality of care for patients with ASMD with or without enzyme replacement therapy (ERT).
Asunto(s)
Enfermedad de Niemann-Pick Tipo A , Enfermedades de Niemann-Pick , Adulto , Humanos , Consenso , Mutación , Enfermedad de Niemann-Pick Tipo A/genética , Esfingomielina Fosfodiesterasa/genética , Revisiones Sistemáticas como AsuntoRESUMEN
Autosomal Dominant Hypercholesterolemia (ADH) is caused by LDLR and APOB mutations. However, genetically diagnosed ADH patients do not always exhibit the expected hypercholesterolemic phenotype. Of 4,669 genetically diagnosed ADH patients, identified through the national identification screening program for ADH, 75 patients (1.6%) had LDL-cholesterol (LDL-C) levels below the 50th percentile for age and gender prior to lipid-lowering therapy. The genes encoding APOB, PCSK9, and ANGPTL3 were sequenced in these subjects to address whether monogenic dominant loss-of-function mutations underlie this paradoxical phenotype. APOB mutations, resulting in truncated APOB, were found in five (6.7%) probands, reducing LDL-C by 56%. Rare variants in PCSK9, and ANGPTL3 completely correcting the hypercholesterolemic phenotype were not found. The common variants p.N902N, c.3842+82T>A, p.D2312D, and p.E4181K in APOB, and c.1863+94A>G in PCSK9 were significantly more prevalent in our cohort compared to the general European population. Interestingly, 40% of our probands carried at least one minor allele for all four common APOB variants compared to 1.5% in the general European population. While we found a low prevalence of rare variants in our cohort, our data suggest that regions in proximity of the analyzed loci, and linked to specific common haplotypes, might harbor additional variants that correct an ADH phenotype.
Asunto(s)
Angiopoyetinas/genética , Apolipoproteínas B/genética , LDL-Colesterol/sangre , Hiperlipoproteinemia Tipo II/sangre , Hiperlipoproteinemia Tipo II/genética , Mutación , Proproteína Convertasas/genética , Serina Endopeptidasas/genética , Adulto , Proteína 3 Similar a la Angiopoyetina , Proteínas Similares a la Angiopoyetina , Femenino , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Proproteína Convertasa 9 , Adulto JovenRESUMEN
PCSK9 proprotein convertase subtilisin/kexin type (PCSK9) is a crucial protein in LDL cholesterol (LDL-C) metabolism by virtue of its pivotal role in the degradation of the LDL receptor. In recent years, both in vitro and in vivo studies have greatly supplemented our understanding of the (patho)physiological role of PCSK9 in human biology. In the current review, we summarize studies published or in print before May 2012 concerning the physiological role of PCSK9 in cholesterol metabolism. Moreover, we briefly describe the clinical phenotypes encountered in carriers of mutations in the gene encoding PCSK9. As PCSK9 has emerged as a novel target for LDL-C lowering therapy, methods to inhibit PCSK9 will also be reviewed. Initial data from investigations of PCSK9 inhibition in humans are promising and indicate that PCSK9 inhibition may be a viable new therapeutic option for the treatment of dyslipidemia and associated cardiovascular diseases.
Asunto(s)
Proproteína Convertasas , Serina Endopeptidasas , Anticolesterolemiantes/farmacología , Anticolesterolemiantes/uso terapéutico , Enfermedades Cardiovasculares/tratamiento farmacológico , Colesterol/metabolismo , Dislipidemias/tratamiento farmacológico , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Fenotipo , Proproteína Convertasa 9 , Proproteína Convertasas/antagonistas & inhibidores , Proproteína Convertasas/genética , Proproteína Convertasas/metabolismo , Serina Endopeptidasas/genética , Serina Endopeptidasas/metabolismoRESUMEN
OBJECTIVE: Endoscopic retrograde cholangiopancreaticography (ERCP) can be complicated by post-ERCP cholangitis even when performed by experienced endoscopists. Therefore, antibiotic prophylaxis is recommended for certain patients, but controversy exists as to which patient groups really benefit from this strategy. We retrospectively evaluated the use of antibiotics in a primary teaching hospital in the Netherlands with regard to the incidence of post-ERCP cholangitis and cholecystitis. MATERIAL AND METHODS: Retrospective single-center evaluation in a primary teaching hospital. All consecutive ERCPs between 2000 and 2006 were studied. Primary end point was the incidence of post-ERCP cholangitis and cholecystitis, divided into four categories: definite, likely, possible and unlikely. Additionally, occurrence of complications such as pneumonia, post-ERCP pancreatitis, perforation of the duodenum, substantial bleeding and the need for re-ERCP within 5 days was scored. RESULTS: Five hundred forty ERCPs in 327 patients were screened. Of these, 292 ERCPs performed in 193 patients were included. Eight ERCPs (2.7%) of all ERCPs were followed by definite cholangitis and two ERCPs (0.7%) by likely cholangitis. The occurrence rate of ERCP-related complications remained low. CONCLUSIONS: This study shows that with our current policy of restricted use of antibiotic prophylaxis the overall incidence of biliary tract infections is low.
Asunto(s)
Antibacterianos/uso terapéutico , Profilaxis Antibiótica , Colangiopancreatografia Retrógrada Endoscópica/efectos adversos , Colangitis/microbiología , Colangitis/prevención & control , Colecistitis/microbiología , Colecistitis/prevención & control , Anciano , Anciano de 80 o más Años , Enfermedades Duodenales/etiología , Escherichia coli , Infecciones por Escherichia coli/microbiología , Femenino , Fiebre/etiología , Gemella , Humanos , Perforación Intestinal/etiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae , Masculino , Persona de Mediana Edad , Pancreatitis/etiología , Selección de Paciente , Neumonía/etiología , Hemorragia Posoperatoria/etiología , Estudios Retrospectivos , Infecciones Estafilocócicas/microbiologíaRESUMEN
INTRODUCTION: Several new treatment modalities are being developed for lysosomal storage disorders (LSDs), including gene therapy. As the currently available treatment options and their influence on disease progression differ greatly within the spectrum of LSDs, willingness to undergo gene therapy might vary among patients with LSDs and/or their representatives. The width of the LSD spectrum is illustrated by the differences between type 1 Gaucher disease, Fabry disease and Mucopolysaccharidosis type III (MPS III). For type 1 Gaucher and Fabry disease several therapies are available, resulting in a near normal or improved, but individually varying, prognosis. No treatment options are available for MPS III. AIM: To identify factors influencing patients' and/or their representatives' decisions regarding undergoing gene therapy. METHODS: Focus group discussions and semi-structured interviews were conducted with patients with type 1 Gaucher disease, Fabry disease and MPS III. Parents of MPS III patients were included as patients' representatives. RESULTS: Nine Gaucher patients, 23 Fabry patients, two adult MPS III patients and five parents of MPS III patients participated in the study. The five main themes that arose were: outcome of gene therapy, risks and side effects, burden of gene therapy treatment, current situation and ethical aspects. Participants' views ranged from hesitance to eagerness to undergo gene therapy, which seemed to be mostly related to disease severity and currently available treatment options. Severe disease, limited treatment options and limited effectiveness of current treatment augmented the willingness to choose gene therapy. Gaucher and Fabry patients deemed the burden of treatment important. Fabry and MPS III patients and parents considered outcome important, suggesting hope for improvement. When asked to rank the factors discussed in the focus group discussions, Gaucher patients ranked outcome low, which could indicate a more cautious attitude towards gene therapy. CONCLUSION: This study underlines the importance of exploring patients' needs and expectations before using limited resources in the development of therapies for patient groups of which a significant subset may not be willing to undergo that specific therapy.
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Enfermedad de Fabry , Enfermedad de Gaucher , Enfermedades por Almacenamiento Lisosomal , Mucopolisacaridosis III , Adulto , Humanos , Enfermedad de Fabry/genética , Enfermedad de Fabry/terapia , Enfermedad de Gaucher/genética , Enfermedad de Gaucher/terapia , Terapia Genética , Enfermedades por Almacenamiento Lisosomal/terapia , Enfermedades por Almacenamiento Lisosomal/tratamiento farmacológico , LisosomasRESUMEN
BACKGROUND: Homozygous familial hypercholesterolemia (hoFH) is either diagnosed on the identification of pathogenic genetic variants in LDLR, APOB, or PCSK9 or by phenotypic parameters of which an extremely elevated LDL-C level >13 mmol/L (>500 mg/dL) is the most prominent hallmark. Little is known about the clinical spectrum in children with hoFH. OBJECTIVE: We set out to investigate the phenotypical spectrum of genetically defined hoFH in our pediatric cohort and evaluated how many pediatric patients, now classified as heterozygous, carry a second mutation, which would reclassify these patients as hoFH. METHODS: We analyzed the data of a total of 1903 children with molecularly proven FH. Subsequently we performed candidate gene sequencing in the cohort of heterozygous familial hypercholesterolemia children in whom the LDL-C level was above the lowest level measured in the pediatric patients with hoFH. RESULTS: Of our 13 hoFH children, 8 (62%) had LDL-C levels below the clinical hoFH criteria of 13 mmol/L (500 mg/dL). In the remaining 1890 patients with heterozygous familial hypercholesterolemia, 64 (3.4%) had LDL-C levels equal to or above the lowest LDL-C level in a patient with hoFH carrying 2 deleterious variants (8.36 mmol/L or 323.3 mg/dL). No additional pathogenic variants in LDLR and APOB were identified. In 2 related patients, a PCSK9 gain of function mutation was found. CONCLUSION: We show that LDL-C levels vary among pediatric patients with molecularly proven hoFH, and that most of these patients do not meet the clinical LDL-C criteria for hoFH. The levels overlap with LDL-C levels in true heterozygous patients. This warrants a critical reappraisal of the current LDL-C cutoffs for the phenotypic diagnosis of hoFH in children.
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Variación Genética , Homocigoto , Hiperlipoproteinemia Tipo II/genética , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Fenotipo , Adulto JovenRESUMEN
BACKGROUND AND AIMS: Lysosomal acid lipase deficiency (LAL-D) is a lysosomal storage disorder. In severe cases, it can cause life-threatening organ failure due to lipid substrates accumulation. However, mild phenotypes of this disorder are increasingly recognized. The aim of this study is to determine the number of missed LAL-D patients in a large pediatric hospital population. METHODS: In a retrospective data mining study, the medical files of children, who visited the outpatient clinic at a university hospital between 2000 and 2016, with high plasma low density lipoprotein cholesterol (LDL-C) levels, were evaluated. Previously developed LAL-D screening criteria, with lipid and alanine aminotransferase (ALT) values adjusted for children, were used to analyze which children are suspect for LAL-D. For suspicion of LAL-D, at least 3 out of 5 screening criteria had to be met. Subsequently data on presentation and follow-up were collected to determine if the clinical picture was compatible with LAL-D. RESULTS: We identified 2037 children with high LDL-C levels. Of those, 36 children complied with ≥3 screening criteria. Thirty-one of those had an underlying disorder other than LAL-D that explained the abnormalities and, in the 5 remaining children, ALT and lipid levels normalized spontaneously, thus excluding LAL-D. CONCLUSIONS: This study shows that retrospective data mining is unlikely to yield a significant number of LAL-D cases in children. The screening algorithm adjusted for children seems useful and accurate in the selection of children for further testing, suggesting it can be applied prospectively, although further validation is warranted.
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Enfermedad de Acumulación de Colesterol Éster/diagnóstico , LDL-Colesterol/sangre , Minería de Datos , Enfermedad de Wolman/diagnóstico , Adolescente , Alanina Transaminasa/metabolismo , Algoritmos , Cardiología/normas , Niño , Preescolar , Enfermedad de Acumulación de Colesterol Éster/metabolismo , Femenino , Humanos , Lactante , Recién Nacido , Hígado/metabolismo , Masculino , Tamizaje Masivo/métodos , Pacientes Ambulatorios , Fenotipo , Estudios Retrospectivos , Esterol Esterasa/genética , Enfermedad de Wolman/metabolismo , Enfermedad de WolmanRESUMEN
BACKGROUND: Autosomal recessive hypercholesterolemia (ARH) is a rare lipid disorder characterized by premature atherosclerotic cardiovascular disease (ASCVD). There are sparse data for clinical management and cardiovascular outcomes in ARH. OBJECTIVES: Evaluation of changes in lipid management, achievement of low-density lipoprotein cholesterol (LDL-C) goals and cardiovascular outcomes in ARH. METHODS: Published ARH cases were identified by electronic search. All corresponding authors and physicians known to treat these patients were asked to provide follow-up information, using a standardized protocol. RESULTS: We collected data for 52 patients (28 females, 24 males; 31.1 ± 17.1 years of age; baseline LDL-C: 571.9 ± 171.7 mg/dl). During a mean follow-up of 14.1 ± 7.3 years, there was a significant increase in the use of high-intensity statin and ezetimibe in combination with lipoprotein apheresis; in 6 patients, lomitapide was also added. Mean LDL-C achieved at nadir was 164.0 ± 85.1 mg/dl (-69.6% from baseline), with a better response in patients taking lomitapide (-88.3%). Overall, 23.1% of ARH patients reached LDL-C of <100 mg/dl. During follow-up, 26.9% of patients had incident ASCVD, and 11.5% had a new diagnosis of aortic valve stenosis (absolute risk per year of 1.9% and 0.8%, respectively). No incident stroke was observed. Age (≥30 years) and the presence of coronary artery disease at diagnosis were the major predictors of incident ASCVD. CONCLUSIONS: Despite intensive treatment, LDL-C in ARH patients remains far from targets, and this translates into a poor long-term cardiovascular prognosis. Our data highlight the importance of an early diagnosis and treatment and confirm the fact that an effective treatment protocol for ARH is still lacking.
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Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/epidemiología , Hipercolesterolemia/sangre , Hipercolesterolemia/epidemiología , Adolescente , Adulto , Anciano , Enfermedades Cardiovasculares/diagnóstico , Niño , Preescolar , LDL-Colesterol/sangre , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Hipercolesterolemia/diagnóstico , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven , Hiperlipoproteinemia Tipo IIIRESUMEN
Eprotirome, a liver specific thyroid hormone agonist, was shown to induce significant increases in markers of liver injury along with a modest decrease in atherogenic lipids and lipoproteins. To get more insight into whether these effects on liver parameters were compound specific or the effect of mimicking thyrotoxicosis, we studied the effects of supra-physiological levothyroxine dosages on liver parameters, lipids and lipoproteins. We used data of a single-blinded, randomized controlled crossover trial. Herein, healthy volunteers received levothyroxine or no medication for 14 days. Thyroid hormone excess did not induce clinically relevant changes in liver parameters, while significant reductions in total cholesterol, low-density lipoprotein-cholesterol as well as apolipoprotein-B levels were observed in the intervention periods compared with the control periods. Supra-physiological thyroid hormone levels did not induce clinically relevant increases in markers of liver injury after 2 weeks of exposure, while it reduced total cholesterol, low-density lipoprotein cholesterol and apolipoprotein B levels. This suggests that the effects of eprotirome on liver parameters in previous studies were either off-target and compound specific or due to drug-drug interaction at the level of the liver. The results of our study are relevant for the development of novel thyroid hormone agonists to reduce atherogenic lipoproteins.
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Lípidos/sangre , Lipoproteínas/sangre , Hígado/efectos de los fármacos , Tiroxina/administración & dosificación , Adulto , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Enzimas/sangre , Femenino , Voluntarios Sanos , Humanos , Hígado/metabolismo , Masculino , Triyodotironina/sangreRESUMEN
BACKGROUND: Patients with autosomal dominant hypercholesterolemia (ADH), caused by mutations in either low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin-kexin type 9 (PCSK9) are characterized by high low-density lipoprotein cholesterol levels and in some studies also high lipoprotein(a) (Lp(a)) levels were observed. The question remains whether this effect on Lp(a) levels is gene-dose-dependent in individuals with either 0, 1, or 2 LDLR or APOB mutations. OBJECTIVE: We set out to study whether Lp(a) levels differ among bi-allelic ADH mutation carriers, and their relatives, in the Netherlands. METHODS: Bi-allelic ADH mutation carriers were identified in the database of the national referral laboratory for DNA diagnostics of inherited dyslipidemias. Family members were invited by the index cases to participate. Clinical parameters and Lp(a) levels were measured in bi-allelic ADH mutation carriers and their heterozygous and unaffected relatives. RESULTS: We included a total of 119 individuals; 34 bi-allelic ADH mutation carriers (20 homozygous/compound heterozygous LDLR mutation carriers (HoFH), 2 homozygous APOB mutation carriers (HoFDB), and 12 double heterozygotes for an LDLR and APOB mutation), 63 mono-allelic ADH mutation carriers (50 heterozygous LDLR [HeFH], 13 heterozygous APOB [HeFDB] mutation carriers), and 22 unaffected family members. Median Lp(a) levels in unaffected relatives, HeFH, and HoFH patients were 19.9 (11.1-41.5), 24.4 (5.9-70.6), and 47.3 (14.9-111.7) mg/dL, respectively (P = .150 for gene-dose dependency). Median Lp(a) levels in HeFDB and HoFDB patients were 50.3 (18.7-120.9) and 205.5 (no interquartile range calculated), respectively (P = .012 for gene-dose-dependency). Double heterozygous carriers of LDLR and APOB mutations had median Lp(a) levels of 27.0 (23.5-45.0), which did not significantly differ from HoFH and HoFDB patients (P = .730 and .340, respectively). CONCLUSION: A (trend toward) increased plasma Lp(a) levels in homozygous ADH patients compared with both heterozygous ADH and unaffected relatives was observed. Whether increased Lp(a) levels in homozygous ADH patients add to the increased cardiovascular disease risk and whether this risk can be reduced by therapies that lower both low-density lipoprotein cholesterol and Lp(a) levels remains to be elucidated.