El déficit de lipasa ácida lisosomal como paradigma de enfermedad de depósito multisistémica / Lysosomal acid lipase deficiency as a paradigm of multisystemic storage disease

Las enfermedades de depósito lisosomal son un grupo de enfermedades que ha cambiado su pronóstico y manejo clínico en los últimos 15 años gracias a la aparición de tratamientos enzimáticos sustitutivos. La mayoría de las formas clínicas diagnosticadas eran síndromes clásicos graves; el avance de los métodos diagnósticos de función enzimática hace que se hayan diagnosticado e identificado formas más leves que han pasado desapercibidas, pero que a pesar de ello asocian una elevada morbimortalidad, y en las cuales el tratamiento es incluso más efectivo que en las formas graves. El déficit de lipasa ácida lisosomal es una de estas enfermedades lisosomales por depósito de ésteres de colesterol y triglicéridos que cumplen con todas estas características. El tratamiento enzimático sustitutivo con la enzima recombinante sebelipasa ha cambiado el pronóstico infausto de las formas graves. Los métodos diagnósticos de análisis enzimático en gota seca están identificando formas más leves en la infancia tardía y la vida adulta en pacientes con hipercolesterolemia y afectación hepática que estaban sin diagnóstico o mal diagnosticados.(AU)

Lysosomal storage diseases are a group of diseases whose prognosis and clinical management have changed in the last 15 years thanks to the appearance of enzyme replacement treatments. Most of the diagnosed clinical forms were severe classic syndromes; the advance of diagnostic methods of enzymatic function has meant that milder forms that had previously gone unnoticed have been diagnosed and identified. However, in spite of this they are associated with high morbidity and mortality, and in which treatment is even more effective than in severe forms. The lysosomal acid lipase deficit is one of these lysosomal diseases due to the deposition of cholesterol esters and triglycerides that fulfill all these characteristics. Enzyme replacement treatment with the recombinant enzyme sebelipase has changed the poor prognosis of the severe forms. Diagnostic methods of dry smear enzyme analysis are identifying milder forms in late childhood and adult life in patients with hypercholesterolemia and liver involvement who were undiagnosed or misdiagnosed.(AU)

Prevalence of p.G87V and p.Gln298=Variations in LIPA Gene Within Middle Eastern Population Living Around Los Angeles.

Background: The LIPA gene encodes for lysosomal acid lipase (LAL), which catalyzes the hydrolysis of cholesterol esters and triglycerides. Variations in the LIPA gene impair LAL activity, predisposing patients to a rare metabolic disorder called LAL deficiency (LAL-D). The lack of functioning LAL promotes lipid accumulation and subsequent dyslipidemia, which can increase the likelihood of complications in both infants and adults. Although the worldwide prevalence is 1:500,000 births, the frequency in Mizrahi Jewish populations is projected to be as high as 1 in every 4200 births (Valles-Ayoub et al.) based on the LIPA p.G87V variant frequency among 162 individuals. Materials and Methods: This study was conducted to validate the previously reported prevalence of LAL-D in the Mizrahi Jewish population based on the pathogenic LIPA missense variants in exon 4 (c.260G>T; p.G87V) and exon 8 (c.894G>A; p.Gln298=) using a larger cohort of those with Middle Eastern ancestry living around Los Angeles. Among the 1184 individual samples sequenced, 660 self-reported as Mizrahi Jewish, while the remaining 524 came from other Middle Eastern groups labeled as "non-Jewish." Results: Of the 1184 samples, 22 alleles of the exon 4 variant were identified (1.85%), and 2 alleles of the exon 8 variant were identified (0.16%). For the exon 4 variant, 20 of 22 (90.9%) heterozygotes were Mizrahi Jewish, while 2 of 22 (9.09%) heterozygotes were "non-Jewish." For the exon 8 variant, 2 of 2 (100%) heterozygotes were Mizrahi Jewish. This suggests that the prevalence of LAL-D in this population is 1 in 900, which suggests that LAL-D may be 4.6% higher in the Mizrahi Jewish population in previous reports. Conclusion: These findings show increased prevalence of LIPA gene exon 4 variation p.G87V in the Middle East population when compared to the general population, indicating the need for prenatal screening in those of Mizrahi Jewish ancestry.

Wolman disease presenting with hemophagocytic lymphohistiocytosis syndrome and a novel LIPA gene variant: a case report and review of the literature.

BACKGROUND: Wolman disease is a rare disease caused by the absence of functional liposomal acid lipase due to mutations in LIPA gene. It presents with organomegaly, malabsorption, and adrenal calcifications. The presentations can resemble hemophagocytic lymphohistiocytosis, the life threatening hyperinflammatory disorder. Since the disease is very rare, clinicians might not think of it when a patient presents with hemophagocytic lymphohistiocytosis, and the opportunity to treat it properly can be lost, thus leading to demise of the child. CASE PRESENTATION: We present a 4.5-month-old Caucasian boy with fever, icterus, and hepatosplenomegaly who was treated according to presumed hemophagocytic lymphohistiocytosis disease. Wolman disease was diagnosed after the death of the child. There are some case reports in the literature presenting patients with Wolman disease primarily diagnosed as hemophagocytic lymphohistiocytosis, which we discuss in this review. The genetic analysis revealed after his demise was compatible with Wolman disease, introducing a novel mutation in LIPA gene: exon 4: NM_001127605: c. G353A (p.G118D), which converts the glycine amino acid to aspartic acid. CONCLUSIONS: Considering the similarities in presentation of Wolman disease and hemophagocytic lymphohistiocytosis, the patient's life can be saved if special attention is paid to presenting features of a patient with suspected hemophagocytic lymphohistiocytosis, that is special attention to symptoms, findings on physical exams, laboratory values, and radiologic findings, and the proper treatment is urgently initiated. Reporting the novel mutations of Wolman disease can help geneticists interpret the results of their patients' genetic studies appropriately, leading to correct diagnosis and treatment.

Lysosomal acid lipase deficiency manifestations in children and adults: Baseline data from an international registry.

BACKGROUND AND AIMS: Lysosomal acid lipase deficiency (LAL-D) is a rare, autosomal recessive disease involving lysosomal accumulation of cholesteryl esters and triglycerides. The International Lysosomal Acid Lipase Deficiency Registry (NCT01633489), established in 2013 to understand LAL-D natural history and long-term outcomes, is accessible to centres caring for patients diagnosed by deficient LAL activity and/or biallelic pathogenic LIPA variants. We describe the registry population enrolled through 2 May 2022. METHODS: In this prospective observational study, we analysed demographic and baseline clinical characteristics of children (ages ≥6 months to <18 years) and adults diagnosed with LAL-D. RESULTS: Of 228 patients with confirmed disease, 61% were children; 202/220 (92%) with data on race were white. Median age was 5.5 years at sign/symptom onset and 10.5 years at diagnosis; median time from sign/symptom onset to diagnostic testing was 3.3 years. The most common manifestations raising suspicion of disease were elevated alanine (70%) and aspartate aminotransferase levels (67%) and hepatomegaly (63%). Among 157 with reported LIPA mutations, 70 were homozygous and 45 were compound heterozygous for the common exon 8 splice junction pathogenic variant (E8SJM-1). Seventy percent (159/228) of patients had dyslipidaemia. Among 118 with liver biopsies, 63% had microvesicular steatosis exclusively, 23% had mixed micro- and macrovesicular steatosis and 47% had lobular inflammation. Of 78 patients with fibrosis-stage data, 37% had bridging fibrosis and 14% had cirrhosis. CONCLUSIONS: Although LAL-D signs/symptoms occur early, diagnosis is often delayed. Abnormal transaminase levels associated with hepatomegaly and dyslipidaemia should raise suspicion and prompt earlier diagnosis of LAL-D. TRIAL REGISTRATION NUMBER: NCT01633489.

Recent insights into lysosomal acid lipase deficiency.

Lysosomal acid lipase (LAL) is the sole enzyme known to degrade neutral lipids in the lysosome. Mutations in the LAL-encoding LIPA gene lead to rare lysosomal lipid storage disorders with complete or partial absence of LAL activity. This review discusses the consequences of defective LAL-mediated lipid hydrolysis on cellular lipid homeostasis, epidemiology, and clinical presentation. Early detection of LAL deficiency (LAL-D) is essential for disease management and survival. LAL-D must be considered in patients with dyslipidemia and elevated aminotransferase concentrations of unknown etiology. Enzyme replacement therapy, sometimes in combination with hematopoietic stem cell transplantation (HSCT), is currently the only therapy for LAL-D. New technologies based on mRNA and viral vector gene transfer are recent efforts to provide other effective therapeutic strategies.

Pediatric patients with lysosomal acid lipase deficiency.

Lysosomal acid lipase (LAL) deficiency is a rare, autosomal recessive disease caused by mutations in the LIPA gene, which produces cholesteryl ester and triglyceride accumulation predominantly in hepatocytes, adrenal glands, and gastrointestinal tract. We describe two new cases occurring in siblings, aged 5 and 7 years, who presented with hepatomegaly, dyslipidemia, and abnormal liver function. Percutaneous liver biopsy revealed portal inflammation, hypertrophic Kupffer cells with a foamy appearance and microvesicular steatosis with fibrosis. Immunostaining for lysosomal markers, cathepsin D and LAMP1 reflected the lysosomal nature of the lipid vacuoles. After enzymatic confirmation, enzyme replacement therapy was initiated for both siblings. Follow-up transaminase levels and lipid profiles showed a notable decrease in AST and ALT and a slight increase in HDL cholesterol. It is crucial to increase awareness of this rare condition among clinicians and pathologists. The expression of lysosomal markers around the lipid vacuoles might help diagnose LAL deficiency in pediatric patients.

Lysosomal Acid Lipase Deficiency: Genetics, Screening, and Preclinical Study.

Lysosomal acid lipase (LAL) is a lysosomal enzyme essential for the degradation of cholesteryl esters through the endocytic pathway. Deficiency of the LAL enzyme encoded by the LIPA gene leads to LAL deficiency (LAL-D) (OMIM 278000), one of the lysosomal storage disorders involving 50-60 genes. Among the two disease subtypes, the severe disease subtype of LAL-D is known as Wolman disease, with typical manifestations involving hepatomegaly, splenomegaly, vomiting, diarrhea, and hematopoietic abnormalities, such as anemia. In contrast, the mild disease subtype of this disorder is known as cholesteryl ester storage disease, with hypercholesterolemia, hypertriglyceridemia, and high-density lipoprotein disappearance. The prevalence of LAL-D is rare, but several treatment options, including enzyme replacement therapy, are available. Accordingly, a number of screening methodologies have been developed for this disorder. This review summarizes the current discussion on LAL-D, covering genetics, screening, and the tertiary structure of human LAL enzyme and preclinical study for the future development of a novel therapy.

Could lysosomal acid lipase enzyme activity be used for clinical follow-up in cryptogenic cirrhosis?

BACKGROUND: Cholesterol ester storage disease (CESD) is one of the rare causes that should be kept in mind in the etiology of cirrhosis. Recent studies detected that significantly reduced lysosomal acid lipase deficiency enzyme (LAL) in patients with cryptogenic cirrhosis (CC). Moreover, studies have evaluated that LAL activity is as effective as scoring systems in assessing the severity of cirrhosis. In this study, we aimed to investigate the CESD with LAL level and mutation analysis of LIPA gene in patients diagnosed with CC and to compare LAL activities between patients with CC and healthy volunteers. METHODS: Laboratory parameters and cirrhosis stage (CHILD and MELD) were recorded for the patient group included in the study. In addition, blood samples were taken from each case included in the study for LAL activity determination and LIPA gene analysis. RESULTS: A statistically significant decrease in LAL activity was found in patients diagnosed with CC compared to the healthy group. LIPA gene analysis did not detect CESD in any patient group. Correlation analysis showed a positive correlation between LAL activity and white blood cell and platelet counts in both healthy volunteers and CC patient groups. In the univariate and multivariate logistic regression analysis of the parameters associated with the MELD of ≥10 in patients with CC, significant relationship was found between the MELD of ≥10 and the LAL activity. DISCUSSION: In our study, LAL activity was significantly lower in CC patients than in the normal population. LAL activity level appears to be a parameter that can be used to assess the severity of cirrhosis.

Clinical insights from Wolman disease: Evaluating infantile hepatosplenomegaly.

There is a broad differential diagnosis of infantile hepatosplenomegaly, with some etiologies being debilitating and treatable. A structured approach to history, examination, and laboratory and radiographic findings is important in diagnosis. Herein, we present a case of Wolman disease presenting as hepatosplenomegaly in an infant. This case details important learning points to help distinguish the diagnosis of Wolman disease from other conditions with overlapping clinical features, such as hemophagocytic lymphohistiocytosis (HLH). The advent of enzyme replacement therapy has dramatically changed the natural history of Wolman disease, and this child showed remarkable improvement with treatment. This child was later found to have extensive adenopathy with retroperitoneal lymph node biopsy demonstrating diffuse infiltration by lipid-laden macrophages, fatty deposits, cholesterol crystals, and calcifications. Similar to the collection of characteristic cells in other lysosomal storage disorders, we postulate that this is characteristic of underlying Wolman disease. We conclude with a summary of learning points from this presentation on infantile hepatosplenomegaly, pertinent to the geneticist, pediatrician, and pediatric subspecialists.

"Why them, why me, why us?" The experiences of parents of children with lysosomal acid lipase deficiency: an interpretative phenomenological analysis study.

BACKGROUND: Lysosomal acid lipase deficiency (LALD) is an ultra-rare, inherited metabolic disease within the category of lysosomal storage disorders, affecting an infant's ability to metabolise cholesterol. Developments in treatment, including Enzyme Replacement Therapy, have proven successful, with some children living for a number of years with treatment, although the future still remains unknown. The aim of this study was to explore the lived experiences of parents of children with LALD. MAIN TEXT: Participants were recruited from across the United Kingdom between 2020 and 2021. Eight parents (five mothers and three fathers) whose child had a confirmed diagnosis of LALD were interviewed. Data collected from the semi-structured interviews were audio-record, transcribed and analysed using Interpretative Phenomenological Analysis (IPA). Three superordinate and nine subordinate themes emerged from the data: (1) Uncertainty-a double-edged sword (plunged into an uncertain world, living life with worry and walking the tightrope of stability), (2) Powerless against a shared battle with LALD (a helpless parent, a joint battle, protection against distress and a vulnerable parent needing help) and 3) Accepting a life with LALD (coming to terms with a diagnosis of LALD and a hidden condition). CONCLUSIONS: The findings of this study highlight that the diagnosis of LALD proves to be a very challenging and emotionally distressing time in parents' lives, with increased uncertainty about what the future will hold for their child. This study signified the importance of healthcare pathways and service provisions to support parents and their children throughout diagnosis and beyond.

Lysosomal acid lipase deficiency in pediatric patients: a scoping review

Abstract Objective: Lysosomal acid lipase deficiency (LAL-D) is an underdiagnosed autosomal recessive disease with onset between the first years of life and adulthood. Early diagnosis is crucial for effective therapy and long-term survival. The objective of this article is to recognize warning signs among the clinical and laboratory characteristics of LAL-D in pediatric patients through a scope review. Sources: Electronic searches in the Embase, PubMed, Livivo, LILACS, Web of Science, Scopus, Google Scholar, Open Gray, and ProQuest Dissertations and Theses databases. The dataset included observational studies with clinical and laboratory characteristics of infants, children and adolescents diagnosed with lysosomal acid lipase deficiency by enzyme activity testing or analysis of mutations in the lysosomal acid lipase gene (LIPA). The reference selection process was performed in two stages. The references were selected by two authors, and the data were extracted in June 2020. Summary of the findings: The initial search returned 1593 studies, and the final selection included 108 studies from 30 countries encompassing 206 patients, including individuals with Wolman disease and cholesteryl ester storage disease (CESD). The most prevalent manifestations in both spectra of the disease were hepatomegaly, splenomegaly, anemia, dyslipidemia, and elevated transaminases. Conclusions: Vomiting, diarrhea, jaundice, and splenomegaly may be correlated, and may serve as a starting point for investigating LAL-D. Familial lymphohistiocytosis should be part of the differential diagnosis with LAL-D, and all patients undergoing upper gastrointestinal endoscopy should be submitted to intestinal biopsy.

Lysosomal acid lipase deficiency in pediatric patients: a scoping review.

OBJECTIVE: Lysosomal acid lipase deficiency (LAL-D) is an underdiagnosed autosomal recessive disease with onset between the first years of life and adulthood. Early diagnosis is crucial for effective therapy and long-term survival. The objective of this article is to recognize warning signs among the clinical and laboratory characteristics of LAL-D in pediatric patients through a scope review. SOURCES: Electronic searches in the Embase, PubMed, Livivo, LILACS, Web of Science, Scopus, Google Scholar, Open Gray, and ProQuest Dissertations and Theses databases. The dataset included observational studies with clinical and laboratory characteristics of infants, children and adolescents diagnosed with lysosomal acid lipase deficiency by enzyme activity testing or analysis of mutations in the lysosomal acid lipase gene (LIPA). The reference selection process was performed in two stages. The references were selected by two authors, and the data were extracted in June 2020. SUMMARY OF THE FINDINGS: The initial search returned 1593 studies, and the final selection included 108 studies from 30 countries encompassing 206 patients, including individuals with Wolman disease and cholesteryl ester storage disease (CESD). The most prevalent manifestations in both spectra of the disease were hepatomegaly, splenomegaly, anemia, dyslipidemia, and elevated transaminases. CONCLUSIONS: Vomiting, diarrhea, jaundice, and splenomegaly may be correlated, and may serve as a starting point for investigating LAL-D. Familial lymphohistiocytosis should be part of the differential diagnosis with LAL-D, and all patients undergoing upper gastrointestinal endoscopy should be submitted to intestinal biopsy.

Disturbance of lipid homeostasis in lysosomal lipase deficiency ­ pathomechanism, diagnosis and treatment / Zaburzenie homeostazy lipidowej w deficycie lizosomalnej lipazy ­ patomechanizm, diagnostyka i leczenie.

Lysosomal acid lipase (LAL) plays a key role in lipid metabolism through the hydrolysis of cholesteryl esters and triglycerides in lysosomes. LAL deficiency is a rare autosomal recessive lysosomal storage disease caused by deleterious mutations in the LIPA gene. In the case of LAL deficiency, cholesteryl esters and triglycerides accumulate within the lysosomes. The up-regulation of endogenous cholesterol production, increased synthesis of apolipoprotein B (ApoB) and increased production of very-low-density lipoprotein cholesterol (VLDL-C) is observed. The diagnosis is easy due to the currently available method of testing the enzyme activity in a dry blood spot. Molecular analysis is necessary to verify the clinical and biochemical diagnosis and to analyze the genotype-phenotype correlation. Sebelipase alfa is a recombinant human lysosomal lipase intended for use in enzyme replacement therapy in patients with LAL deficiency.

Large-scale screening of lipase acid deficiency in at risk population.

BACKGROUND: Lysosomal acid lipase deficiency (LALD, OMIM#278000) is a rare lysosomal disorder with an autosomal recessive inheritance. The main clinical manifestations are related to a progressive accumulation of cholesteryl esters, triglycerides or both within the lysosome in different organs such as the liver, spleen, and cardiovascular system. A wide range of clinical severity is associated with LALD including a severe very rare antenatal/neonatal/infantile phenotype named Wolman disease and a late-onset form named cholesteryl ester storage disease (CESD). METHODS: This study aimed to investigate a cohort of at-risk patients (4174) presenting with clinical or biological signs consistent with LALD using the assessment of LAL activity on dried blood spots. RESULTS: LAL activity was lower than 0.05 nmol/punch/L (cut-off: 0.12) in 19 patients including 13 CESD and 6 Wolman. Molecular study has been conducted in 17 patients and succeeded in identifying 34 mutated alleles. Fourteen unique variants have been characterized, 7 of which are novel. CONCLUSION: This study allowed to identify a series of patients and expanded the molecular spectrum knowledge of LALD. Besides, a new screening criteria grid based on the clinical/biological data from our study and the literature has been proposed in order to enhance the diagnosis rate in at risk populations.

Wolman's disease presenting with secondary hemophagocytic lymphohistiocytosis: a case report from Saudi Arabia and literature review.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare and potentially fatal syndrome that is characterized by strong activation of the immune system from hyperinflammatory cytokines. Symptoms of HLH patients include fever, hepatosplenomegaly, cytopenia, and hyperferritinemia. Inherited HLH is classified as primary, whereas secondary HLH (sHLH) occurs when acquired from non-inherited reasons that include severe infection, immune deficiency syndrome, autoimmune disorder, neoplasm, and metabolic disorder. Wolman's disease (WD) is a rare and fatal infantile metabolic disorder caused by lysosomal acid lipase deficiency, that exhibits similar clinical signs and symptoms as HLH. This paper reports the case of an infant diagnosed with WD and who presented with sHLH. CASE PRESENTATION: A 4-month-old infant presenting with hepatosplenomegaly, failure to thrive, and other abnormalities. WD diagnosis was confirmed by the presence of the LIPA gene homozygous deletion c.(428 + 1_967-1)_(*1_?)del. The infant also met the HLH-2004 diagnostic criteria. CONCLUSIONS: Metabolic disorder such as WD should be investigated in infants fulfilling the HLH criteria to diagnose the underlying condition. More studies are needed to understand the link between WD and sHLH and to identify appropriate therapies.

Deficiencia de lipasa ácida lisosomal: una causa poco reconocida de dislipemia y disfunción hepática / Lysosomal acid lipase deficiency: A rarely recognised cause of dyslipidaemia and liver dysfunction

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