High incidence of cholesterol gallstone disease in type 1 Gaucher disease: characterizing the biliary phenotype of type 1 Gaucher disease

Challenges in Gaucher disease: Perspectives from an expert panel

This focused review concentrates on eight topics of high importance for Gaucher disease (GD) clinicians and researchers: 1) The consideration of GD as distinct types rather than a spectrum. A review of the literature clearly supports the view that there are distinct types of GD. Type 1 is characterized by the absence of primary neuronopathic involvement, while types 2 and 3 are characterized by progressive primary neuronopathic disease. 2) Neurologic and neuronopathic manifestations. A growing body of evidence indicates that the peripheral nervous system may be involved in GD type 1 and that there may also be signs and symptoms of central nervous system (CNS) disease in this group. However, GD type 1 is characterized by the absence of primary neuronopathic disease, whereas GD types 2 and 3 are characterized by progressive, albeit variable, primary neuronopathic disease. Abnormalities in saccadic eye movements have been suggested as being diagnostic for neuronopathic GD, but they may also occur in GD type 1 and in other inflammatory diseases. 3) The importance of whole GBA1 sequencing. This approach is superior to exome sequencing because of potential effects of deep intronic variants on gene expression. It also has the capacity to detect variant alleles that might be missed with gene panels. 4) Monoclonal gammopathy of undetermined significance (MGUS). The risks of MGUS, multiple myeloma, and non-Hodgkin's lymphoma are elevated in patients with GD compared to the general population and strong evidence indicates that lyso-Gb1 stimulates the formation of monoclonal immunoglobulins (M-protein) in patients with GD and MGUS. 5) Pulmonary involvement in GD. Pulmonary complications can be identified through spirometry in up to 45 % of patients with GD type 1 and 55 % of those with GD type 3. Limited evidence exists that enzyme replacement therapy (ERT) reduces the severity of these complications in patients with GD type 1. 6) Gaucheromas. These may occur in patients with GD types 1 or 3, but there is little detailed information about their inception, mechanisms underlying growth, cellular organization, and biochemical activities, and no definitive guidance for their management. Gaucheromas behave like benign (i.e. non-metastasizing) neoplasms, and it may be reasonable to classify them as such. 7) Bone and joint involvement. Dual-energy X-ray absorptiometry scans alone are insufficient for monitoring all changes in bone that may occur in patients with GD. Quantitative magnetic resonance imaging (MRI) techniques using Dixon quantitative chemical shift imaging have provided results that correlate with GD severity scores, bone complications, and biomarkers for GD bone involvement. Thoracic kyphosis is a common complication of GD types 1 and 3, and there is very limited information regarding the effects of ERT or substrate synthesis inhibition therapy (SSIT) on this condition. 8) Treatment initiation, selection, combination, and switching. Prompt initiation of treatment in pediatric patients is important as GD can lead to impaired growth, lower peak bone mass, and delayed puberty. These adverse outcomes can often be ameliorated or prevented with timely treatment. Either ERT or eliglustat, a SSIT agent, is suitable as first-line treatment of adults with GD. Studies of switching from ERT to eliglustat, or between different ERT products, have indicated that changing treatment is safe, although efficacy outcomes vary. A critical remaining issue is the lack of treatments capable of reaching the CNS to slow or halt the progression of neuronopathic disease in patients with GD type 2 or 3 and potentially reduce the risk of Parkinson's disease in GD type 1 patients and heterozygotes for GBA1 variants.

Acid sphingomyelinase deficiency and Gaucher disease: Underdiagnosed and often treatable causes of hepatomegaly, splenomegaly, and low HDL cholesterol in lean individuals

BACKGROUND

Acid sphingomyelinase deficiency (ASMD) and Gaucher disease type 1 (GD1) are rare inherited sphingolipid disorders with multisystemic manifestations, including liver disease and dyslipidemia. Despite effective treatments, insufficient disease awareness frequently results in diagnostic delays during which irreversible complications occur. We delineated the shared and distinctive features of hepatic, splenic, and lipoprotein phenotypes in ASMD and GD1.

METHODS

We analyzed baseline hepatic, splenic, and lipoprotein phenotypes of untreated adults in pivotal trials of ASMD (ASCEND, N=36) and GD1 (ENGAGE, N=40).

RESULTS

The mean cohort ages were 34.8 years in ASMD and 31.8 years in GD1. Most patients had normal or low body mass index. Moderate hepatosplenomegaly (mean volume in multiples of normal) was common in both cohorts (hepatomegaly 1.53±0.42 and 1.40±0.32, respectively; splenomegaly 11.45±4.36 and 13.20±5.91, respectively). Liver function tests were mildly elevated in ASMD but normal in GD1. In both disorders, mean HDL cholesterol (mg/dL) was profoundly low (22.23±9.14 ASMD; 26.25±8.08 GD1) and correlated inversely with liver volume (r=-0.45 ASMD, p=0.005; r=-0.50 GD1, p=0.001) and spleen volume (r=-0.60 ASMD, p=0.0001; r=-0.63 GD1, p<0.0001). Mean LDL cholesterol (mg/dL) was elevated in ASMD (145.86±49.80) but low in GD1 (68.85±22.53). HDL cholesterol correlated inversely with serum concentrations of lyso-sphingomyelin in ASMD (r=-0.48, p=0.003) and glucosylsphingosine in GD1 (r=-0.63, p<0.0001).

CONCLUSIONS

ASMD and GD1 should be considered in differential diagnosis of patients with unexplained liver and lipid abnormalities, especially young, lean adults with very low HDL and hepatosplenomegaly. HDL emerged as a potential biomarker of disease activity in these sphingolipid disorders.

Insight into the mechanism of gallstone disease by proteomic and metaproteomic characterization of human bile

Introduction

Cholesterol gallstone disease is a prevalent condition that has a significant economic impact. However, the role of the bile microbiome in its development and the host's responses to it remain poorly understood.

Methods

In this study, we conducted a comprehensive analysis of microbial and human bile proteins in 40 individuals with either gallstone disease or gallbladder polyps. We employed a combined proteomic and metaproteomic approach, as well as meta-taxonomic analysis, functional pathway enrichment, and Western blot analyses.

Results

Our metaproteomic analysis, utilizing the lowest common ancestor algorithm, identified 158 microbial taxa in the bile samples. We discovered microbial taxa that may contribute to gallstone formation, including β-glucuronidase-producing bacteria such as Streptococcus, Staphylococcus, and Clostridium, as well as those involved in biofilm formation like Helicobacter, Cyanobacteria, Pseudomonas, Escherichia coli, and Clostridium. Furthermore, we identified 2,749 human proteins and 87 microbial proteins with a protein false discovery rate (FDR) of 1% and at least 2 distinct peptides. Among these proteins, we found microbial proteins crucial to biofilm formation, such as QDR3, ompA, ndk, pstS, nanA, pfIB, and dnaK. Notably, QDR3 showed a gradual upregulation from chronic to acute cholesterol gallstone disease when compared to polyp samples. Additionally, we discovered other microbial proteins that enhance bacterial virulence and gallstone formation by counteracting host oxidative stress, including sodB, katG, rbr, htrA, and ahpC. We also identified microbial proteins like lepA, rtxA, pckA, tuf, and tpiA that are linked to bacterial virulence and potential gallstone formation, with lepA being upregulated in gallstone bile compared to polyp bile. Furthermore, our analysis of the host proteome in gallstone bile revealed enhanced inflammatory molecular profiles, including innate immune molecules against microbial infections. Gallstone bile exhibited overrepresented pathways related to blood coagulation, folate metabolism, and the IL-17 pathway. However, we observed suppressed metabolic activities, particularly catabolic metabolism and transport activities, in gallstone bile compared to polyp bile. Notably, acute cholelithiasis bile demonstrated significantly impaired metabolic activities compared to chronic cholelithiasis bile.

Conclusion

Our study provides a comprehensive metaproteomic analysis of bile samples related to gallstone disease, offering new insights into the microbiome-host interaction and gallstone formation mechanism.

Natural history and management of liver dysfunction in lysosomal storage disorders

Lysosomal storage disorders (LSD) are a rare group of genetic disorders. The major LSDs that cause liver dysfunction are disorders of sphingolipid lipid storage [Gaucher disease (GD) and Niemann-Pick disease] and lysosomal acid lipase deficiency [cholesteryl ester storage disease and Wolman disease (WD)]. These diseases can cause significant liver problems ranging from asymptomatic hepatomegaly to cirrhosis and portal hypertension. Abnormal storage cells initiate hepatic fibrosis in sphingolipid disorders. Dyslipidemia causes micronodular cirrhosis in lipid storage disorders. These disorders must be keenly differentiated from other chronic liver diseases and non-alcoholic steatohepatitis that affect children and young adults. GD, Niemann-Pick type C, and WD also cause neonatal cholestasis and infantile liver failure. Genotype and liver phenotype correlation is variable in these conditions. Patients with LSD may survive up to 4-5 decades except for those with neonatal onset disease. The diagnosis of all LSD is based on enzymatic activity, tissue histology, and genetic testing. Enzyme replacement is possible in GD and Niemann-Pick types A and B though there are major limitations in the outcome. Those that progress invariably require liver transplantation with variable outcomes. The prognosis of Niemann-Pick type C and WD is universally poor. Enzyme replacement therapy has a promising role in cholesteryl ester storage disease. This review attempts to outline the natural history of these disorders from a hepatologist’s perspective to increase awareness and facilitate better management of these rare disorders.

Histomorphometric analysis of liver biopsies of treated patients with Gaucher disease type 1

Gaucher disease (GD) is an autosomal recessive lysosomal disorder caused by a disturbance in the metabolism of glucocerebroside in the macrophages. Most of its manifestations – hepatosplenomegaly, anemia, thrombocytopenia, and bone pain – are amenable to a macrophage-target therapy such as enzyme replacement. However, there is increasing evidence that abnormalities of the liver persist despite the specific GD treatment. In this work, we adapted histomorphometry techniques to the study of hepatocytes in GD using liver tissue of treated patients, developing the first morphometrical method for canalicular quantification in immunohistochemistry-stained liver biopsies, and exploring histomorphometric characteristics of GD. This is the first histomorphometric technique developed for canalicular analysis on histological liver biopsy samples.

Non-immune Hemolysis in Gaucher Disease and Review of the Literature

Gaucher disease (GD) is an autosomal recessive disease characterized by the buildup of glucocerebrosides in macrophages, resulting in the formation of "Gaucher cells." These cells predominantly infiltrate the liver, spleen, and bone marrow leading to hepatosplenomegaly, cytopenia, and bone pain. Anemia in GD is typically considered to result from non-hemolytic processes. Although rare, a higher rate of hemolytic anemia of the autoimmune type has been reported in GD than in the general population. The literature on non-immune hemolytic anemia in GD is scarce. We review the literature on hemolytic anemia in GD and report on a case of non-immune hemolytic anemia secondary to GD. We believe this is the first description of a patient with confirmed GD and symptomatic non-immune hemolytic anemia that responded to GD-specific treatment.

Nutrition in adult patients with selected lysosomal storage diseases

Lysosomal storage disorders (LSDs) are a group of clinically heterogeneous disorders affecting the function of lysosomes and are characterized by an accumulation of undigested substrates within several cell types. In recent years there have been substantial advances in supportive care and drug treatment for some LSDs, leading to improved patient survival, as seen in Gaucher, Pompe and Fabry disease and some Mucopolysaccharidoses; however, many symptoms still persist. Thus it is now even more important to improve patients' quality of life and reduce symptoms and comorbidities. One potential way of achieving this goal is through adjunct nutritional therapy, which is challenging as patients may be overweight with associated consequences, or malnourished, or underweight. Furthermore, drugs used to treat LSDs can modify the metabolic status and needs of patients. There are currently not enough data to make specific dietary recommendations for individual LSDs; however, suggestions can be made for managing clinical manifestations of the diseases, as well as treatment-associated adverse events. The metabolic and nutritional status of adult patients must be regularly assessed and individualized dietary plans may be created to cater to a patient's specific needs. Damage to the autophagic process is a common feature in LSDs that is potentially sensitive to dietary manipulation and needs to be assessed in clinical studies.

Pregnancy outcome in women with Gaucher disease type 1 who had unplanned pregnancies during eliglustat clinical trials

Gaucher disease type 1 (GD1) is an inherited lysosomal storage disorder caused by deficient enzymatic activity of acid β-glucosidase, resulting in accumulation of its substrate glucosylceramide, leading to debilitating visceral, hematologic, and skeletal manifestations. Women with GD1 are at increased risk for complications during pregnancy, delivery, and postpartum. Treatment with enzyme replacement therapy is generally recommended before and during pregnancy to reduce risks. Eliglustat, an oral substrate-reduction therapy, is a first-line treatment for adults with GD1 adults who have extensive, intermediate, or poor CYP2D6-metabolizer phenotypes (>90% of patients). We report on pregnancy outcomes among women in eliglustat trials who had unplanned pregnancies and female partners of men in the trials. In four phase 2 and 3 eliglustat trials of 393 adults with GD1, women of childbearing potential were required to use contraception, have monthly pregnancy tests, and discontinue eliglustat promptly if pregnant. In phase 2 and 3 trials, 18 women had 19 pregnancies, resulting in 14 healthy infants from 13 pregnancies (one set of twins), three elective terminations, one ectopic pregnancy, one spontaneous abortion, and one in utero death. Median estimated eliglustat exposure duration during pregnancy was 38 days. In phase 1 trials (non-GD1 subjects), one woman had a spontaneous abortion. Partners of 16 eliglustat-treated men with GD1 had 18 pregnancies, all resulting in healthy infants. Eliglustat is not approved during pregnancy due to limited data. Guidelines for clinicians and patients with GD that address use of eliglustat in women of childbearing potential are needed.

Liver involvement in Gaucher disease: A practical review for the hepatologist and the gastroenterologist

Gaucher disease (GD), a rare lysosomal storage disorder caused by deficient glucocerebrosidase activity and consequent accumulation of glycosphingolipids in the mononuclear phagocyte system, may progress to disabling and potentially life-threatening complications when left undiagnosed and untreated. Unfortunately, because of non-specific signs and symptoms and lack of awareness, patients with type 1 GD, the most common non-neuropathic variant, frequently experience diagnostic delays. Since splenomegaly and thrombocytopenia are the dominant clinical features in many GD patients leading to first medical contact, the hepatologist and the gastroenterologist need to be aware of this condition. Liver involvement has been reported in the majority of GD patients, and comprises hepatomegaly, with or without liver enzymes alteration, fibrosis/cirrhosis, portal hypertension, focal liver lesions, and cholelithiasis. Moreover, GD is associated with several biochemical alterations of potential interest for the hepatologist and the gastroenterologist, including hypergammaglobulinemia, hyperferritinemia and metabolic abnormalities, that may lead to misdiagnoses with chronic liver diseases of common etiology, such as primary hemochromatosis, autoimmune liver diseases or nonalcoholic fatty liver disease. This comprehensive review, based on the collaborative experience of physicians managing patients with GD, provides practical information on the clinical, histological and radiological hepatic manifestations of GD aiming at facilitating the diagnosis of GD for the hepatologist and the gastroenterologist.

AISF update on the diagnosis and management of adult-onset lysosomal storage diseases with hepatic involvement

Lysosomal storage diseases (LSDs) are a heterogeneous group of inherited disorders caused by loss-of-function mutations in genes encoding for lysosomal enzymes/proteins. The consequence is a progressive accumulation of substrates in these intracellular organelles, resulting in cellular and tissue damage. The overall incidence is about 1/8000 live births, but is likely underestimated. LSDs are chronic progressive multi-systemic disorders, generally presenting with visceromegaly, and involvement of the central nervous system, eyes, the skeleton, and the respiratory and cardiovascular systems. The age at onset and phenotypic expression are highly variable, according to the specific enzymatic defect and tissues involved, the residual activity, and the disease-causing genotype. Enzyme-replacement therapies and substrate-reduction therapies have recently become available, leading to the improvement in symptoms, disease progression and quality of life of affected individuals. Liver involvement and hepatosplenomegaly are frequent features of LSDs and a hallmark of adult-onset forms, frequently leading to medical attention. LSDs should therefore be considered in the differential diagnosis of liver disease with organomegaly. The present document will provide a short overview of adult-onset LSDs with hepatic involvement, highlighting the specificities and systemic manifestations of the ones most frequently encountered in clinical practice, which may hint at the correct diagnosis and the appropriate treatment.

Liver involvement in patients with Gaucher disease types I and III

Background & aims

Gaucher disease (GD) is a multisystemic disease. Liver involvement in GD is not well characterised and ranges from hepatomegaly to cirrhosis and hepatocellular carcinoma. We aim to describe, and assess the effect of treatment, on the hepatic phenotype of a cohort of patients with GD types I and II.

Methods

Retrospective study based on the review of the medical files of the Gaucher Reference Centre of the Hospital de Clínicas de Porto Alegre, Brazil. Data from all GD types I and III patients seen at the centre since 2003 were analysed. Variables were compared as pre- (“baseline”) and post-treatment (“follow-up”).

Results

Forty-two patients (types I: 39, III: 3; female: 22; median age: 35 y; enzyme replacement therapy: 37; substrate reduction therapy: 2; non-treated: 3; median time on treatment-MTT: 124 months) were included. Liver enzyme abnormalities, hepatomegaly, and steatosis at baseline were seen in 19/28 (68%), 28/42 (67%), and 3/38 patients (8%), respectively; at follow-up, 21/38 (55%), 15/38 (39%) and 15/38 (39%). MRI iron quantification showed overload in 7/8 patients (treated: 7; MTT: 55 months), being severe in 2/7 (treated: 2/2; MTT: 44.5 months). Eight patients had liver biopsy (treated: 6; MTT: 58 months), with fibrosis in 3 (treated: 1; time on treatment: 108 months) and steatohepatitis in 2 (treated: 2; time on treatment: 69 and 185 months). One patient developed hepatocellular carcinoma.

Conclusions

GD is a heterogeneous disease that causes different patterns of liver damage even during treatment. Although treatment improves the hepatocellular damage, it is associated with an increased rate of steatosis. This study highlights the importance of a follow-up of liver integrity in these patients.

Endocrine and metabolic disorders in patients with Gaucher disease type 1: a review

Background

Gaucher disease (GD) is one of the most prevalent lysosomal storage diseases and is associated with hormonal and metabolic abnormalities, including nutritional status disorders, hypermetabolic state with high resting energy expenditures, peripheral insulin resistance, hypoadiponectinaemia, leptin and ghrelin impairments, hypolipidaemia, linear growth deceleration and growth hormone deficiency, delayed puberty, hypocalcaemia and vitamin D deficiency. Specific treatments for GD such as enzyme replacement therapy and substrate reduction therapy display significant effects on the metabolic profile of GD patients.

Main body of the abstract

Hormonal and metabolic disturbances observed in both adult and paediatric patients with Gaucher disease type 1 (GD1) are discussed in this review. The PubMed database was used to identify articles on endocrine and metabolic disorders in GD1. GD1 appears to facilitate the development of disorders of nutrition, glucose metabolism and vitamin D insufficiency. Metabolic and hormonal diseases may have a significant impact on the course of the underlying disease and patient quality of life.

Conclusions

Conditions relating to hormones and metabolism can be wide-ranging in GD1. Obtained findings were intrinsic to GD either as a deleterious process or a compensatory response and some changes detected may represent co-morbidities. Actively seeking and diagnosing endocrine and metabolic disorders are strongly recommended in GD1 patients to optimize healthcare.

Inherited metabolic disorders and dyslipidaemia

Monogenic dyslipidaemia is a diverse group of multisystem disorders. Patients may present to various specialities from early childhood to late in adult life, and it usually takes longer before the diagnosis is established. Increased awareness of these disorders among clinicians is imperative for early diagnosis. This best practice review provides an overview of primary dyslipidaemias, highlighting their clinical presentation, relevant biochemical and molecular tests. It also addresses the emerging role of genetics in the early diagnosis and prevention of these disorders.

Ophthalmic manifestations of Gaucher disease: the most common lysosomal storage disorder

Gaucher disease (GD) results from a deficiency of glucocerebrosidase activity and the subsequent accumulation of the enzyme's metabolites, principally glucosylsphingosine and glucosylceramide. There are three principal forms: Type I, which is the most common, is usually considered non-neuronopathic. Type II, III and IIIc manifest earlier and have neurological sequelae due to markedly reduced enzyme activity. Gaucher's can be associated with ophthalmological sequelae but these have not been systematically reviewed. We therefore performed a comprehensive literature review of all such ophthalmic abnormalities associated with the different types of Gaucher disease. We systematically searched the literature (1950 - present) for functional and structural ocular abnormalities arising in patients with Gaucher disease and found that all subtypes can be associated with ophthalmic abnormalities; these range from recently described intraocular lesions to disease involving the adnexae, peripheral nerves and brain. In summary, Gaucher can affect most parts of the eye. Rarely is it sight-threatening; some but not all manifestations are amenable to treatment, including with enzyme replacement and substrate reduction therapy. Retinal involvement is rare but patients with ocular manifestations should be monitored and treated early to reduce the risk of progression and further complications. As Gaucher disease is also associated with Parkinsons disease and may also confer an increased risk of malignancy (particularly haematological forms and melanoma), any ocular abnormalities should be fully investigated to exclude these potential underlying conditions.

Gaucher Disease: New Expanded Classification Emphasizing Neurological Features

Gaucher disease (GD) is a rare inherited metabolic disorder and the most common lysosomal storage disorder, caused by a deficiency in glucocerebrosidase enzyme activity. It has been classified according to the neurological manifestations into three types: type 1, without neuropathic findings, type 2 with acute infantile neuropathic signs and type 3 or chronic neuropathic form. However, report of new variants has led to the expansion of phenotype as a clinical phenotype of GD considered as a continuum of phenotypes. Therefore, it seems that a new classification is needed to cover new forms of the disease.

A Review of Gaucher Disease Pathophysiology, Clinical Presentation and Treatments

Gaucher disease (GD, ORPHA355) is a rare, autosomal recessive genetic disorder. It is caused by a deficiency of the lysosomal enzyme, glucocerebrosidase, which leads to an accumulation of its substrate, glucosylceramide, in macrophages. In the general population, its incidence is approximately 1/40,000 to 1/60,000 births, rising to 1/800 in Ashkenazi Jews. The main cause of the cytopenia, splenomegaly, hepatomegaly, and bone lesions associated with the disease is considered to be the infiltration of the bone marrow, spleen, and liver by Gaucher cells. Type-1 Gaucher disease, which affects the majority of patients (90% in Europe and USA, but less in other regions), is characterized by effects on the viscera, whereas types 2 and 3 are also associated with neurological impairment, either severe in type 2 or variable in type 3. A diagnosis of GD can be confirmed by demonstrating the deficiency of acid glucocerebrosidase activity in leukocytes. Mutations in the GBA1 gene should be identified as they may be of prognostic value in some cases. Patients with type-1 GD-but also carriers of GBA1 mutation-have been found to be predisposed to developing Parkinson's disease, and the risk of neoplasia associated with the disease is still subject to discussion. Disease-specific treatment consists of intravenous enzyme replacement therapy (ERT) using one of the currently available molecules (imiglucerase, velaglucerase, or taliglucerase). Orally administered inhibitors of glucosylceramide biosynthesis can also be used (miglustat or eliglustat).

Case report of cholelithiasis in a patient with type 1 Gaucher disease

•

Case report of cholelithiasis in a patient with type 1 Gaucher disease; which is very intriguing to show this comorbidity.

•

The case was the only known case with this pathology in time of diagnosis in our country (Kosovo).

•

Thus, gallstones and cholecystitis should be considered when abdominal symptoms and liver dysfunctions are seen in these patients.

•

More studies are needed to determine the incidence and prevalence of gallstones in Gaucher disease patients in especially Kosovo.

Introduction

Patients with type 1 Gaucher disease have been reported to be more likely to have cholelithiasis.

Presentation of case

A case of cholelithiasis in a patient with type 1 Gaucher disease; which is very intriguing to show this comorbidity. The case was the only known case with this pathology in time of diagnosis in our country (Kosovo). The patient is a 21-year old girl a known case of type 1 Gaucher disease, at the age of 8 years. The patient underwent elective laparoscopic cholecystectomy. Chronic inflammatory changes and adhesions were obvious during surgery.

Discussion

Type 1 Gaucher disease patients have several risk factors for gallstone formation: increased biliary excretion of glucosylceramide, advanced liver disease and cirrhosis, splenomegaly, inborn error of metabolism, chronic systemic inflammation, T cell dysfunction, and insulin resistance” to risk factors.

Conclusion

Gallstones and cholecystitis should be considered when abdominal symptoms and liver dysfunctions are seen in these patients. More studies are needed in especially Kosovo.

Glucosylsphingosine is a key biomarker of Gaucher disease

Gaucher disease (GD) involves the accumulation of glucosylceramide (GL1) and its deacylated lysolipid, glucosylsphingosine (lyso-GL1) which is implicated in mediating immune dysregulation and skeletal disease. The aim of our study was to assess plasma Lyso-GL1 as a biomarker of GD and its response to therapy. Plasma lyso-GL1 in 169 patients with GD type 1 (GD1) was measured by LC-MS/MS. Significant predictors of plasma LGL1 were assessed by Pearson's correlation coefficient, Wilcoxon Mann Whitney test and multiple linear regression. Propensity scores were used to match patients on treatment mode: Enzyme Replacement Therapy (ERT) vs. Eliglustat Tartrate SRT (ELI-SRT). Plasma Lyso-GL1 levels in healthy controls averaged 1.5 ng/ml (1.3-1.7; 95% CI). In untreated GD patients, the levels were massively elevated (180.9 ng/ml: 95% CI, 145.4-216.5) and imiglucerase ERT resulted in marked reduction (89 ng/ml: 95% CI, 69.2-129.4) (P < 0.001). Lyso-GL1 correlated with chitotriosidase (r = 0.59 P < 0.001), CCL18 (r = 0.62 P <0.001), hepatomegaly (r = 0.28 P < 0.001), splenomegaly (r = 0.27 P = 0.003), splenectomy (P = 0.01) and treatment mode (P < 0.001). By multiple linear regression, the strongest predictors of lyso-GL1 were age (P < 0.001), splenectomy (P = 0.02), Chitotriosidase (P < 0.001) and CCL18 levels (P = 0.001). After propensity score matching to obtain comparable groups of patients on ERT vs ELI-SRT, lyso-GL1 levels were lower among patients receiving ELI-SRT by 113 ng/ml (95% CI: 136-90.3 ng/ml P < 0.001). Plasma lyso-GL1 is a key biomarker of GD. ERT reduced lyso-GL1 levels. By propensity scoring, ELI-SRT resulted in greater reduction of lyso-GL1 than ERT. Am. J. Hematol. 91:1082-1089, 2016. © 2016 Wiley Periodicals, Inc.

Understanding the natural history of Gaucher disease

Gaucher disease is a rare and extraordinarily heterogeneous inborn error of metabolism that exhibits diverse manifestations, a broad range of age of onset of symptoms, and a wide clinical spectrum of disease severity, from lethal disease during infancy to first age of onset of symptoms in octogenarians. Before the advent of the International Collaborative Gaucher Group (ICGG) Gaucher Registry, the understanding of the natural history and phenotypic range of Gaucher disease was based on isolated case reports and small case series. Limited data hindered understanding of the full spectrum of the disease leading to some early misconceptions about Gaucher disease, notably, that nonneuronopathic (type 1) disease was a disease of adults only. The global scope of the ICGG Gaucher Registry, with its vast body of longitudinal data, has enabled a real appreciation of both the phenotypic spectrum of Gaucher disease and its natural history. This body of evidence represents the foundation for accurate assessment of the response to specific therapies for Gaucher disease and to the development of standard-of-care to monitor disease activity. Here, we outline the key developments in delineating the natural history of this highly complex disease and role of the ICGG Gaucher Registry in this effort.

Eliglustat compared with imiglucerase in patients with Gaucher's disease type 1 stabilised on enzyme replacement therapy: a phase 3, randomised, open-label, non-inferiority trial

BACKGROUND

The mainstay of treatment for Gaucher's disease type 1 is alternate-week infusion of enzyme replacement therapy (ERT). We investigated whether patients stable on such treatment would remain so after switching to oral eliglustat, a selective inhibitor of glucosylceramide synthase.

METHODS

In this phase 3, randomised, multinational, open-label, non-inferiority trial, we enrolled adults (aged ≥18 years) who had received ERT for 3 years or more for Gaucher's disease. Patients were randomly allocated 2:1 at 39 clinics (stratified by ERT dose; block sizes of four; computer-generated centrally) to receive either oral eliglustat or imiglucerase infusions for 12 months. Participants and investigators were aware of treatment assignment, but the central reader who assessed organ volumes was masked. The composite primary efficacy endpoint was percentage of patients whose haematological variables and organ volumes remained stable for 12 months (ie, haemoglobin decrease not more than 15 g/L, platelet count decrease not more than 25%, spleen volume increase not more than 25%, and liver volume increase not more than 20%, in multiples of normal from baseline). The non-inferiority margin was 25% for eliglustat relative to imiglucerase, assessed in all patients who completed 12 months of treatment. This trial is registered with ClinicalTrials.gov, number NCT00943111, and EudraCT, number 2008-005223-28.

FINDINGS

Between Sept 15, 2009, and Nov 9, 2011, we randomly allocated 106 (66%) patients to eliglustat and 54 (34%) to imiglucerase. In the per-protocol population, 84 (85%) of 99 patients who completed eliglustat treatment and 44 (94%) of 47 patients who completed imiglucerase treatment met the composite primary endpoint (between-group difference -8·8%; 95% CI -17·6 to 4·2). The lower bound of the 95% CI of -17·6% was within the prespecified threshold for non-inferiority. Dropouts occurred due to palpitations (one patient on eliglustat), myocardial infarction (one patient on eliglustat), and psychotic disorder (one patient on imiglucerase). No deaths occurred. 97 (92%) of 106 patients in the eliglustat group had treatment-emergent adverse events, as did 42 (79%) of 53 in the imiglucerase group (mostly mild or moderate in severity).

INTERPRETATION

Oral eliglustat maintained haematological and organ volume stability in adults with Gaucher's disease type 1 already controlled by intravenous ERT and could be a useful therapeutic option.

FUNDING

Genzyme, a Sanofi company.

Non-neuronopathic lysosomal storage disorders: Disease spectrum and treatments

Distinctive facial features, hepatosplenomegaly or cardiomyopathy with or without associated skeletal dysplasia are clinical manifestations that may be suggestive of an underlying lysosomal storage disorder (LSD), However, these features may not be evident in certain subtypes associated primarily with central nervous system involvement. Age at onset can be broad, ranging from infancy to adulthood. Diagnosis may be delayed, as manifestations may be slow to evolve (taking months to years), particularly in those with later (adult-)onset, and in isolated cases (i.e., those without a prior family history). Diagnosis of individual subtypes can be confirmed using a combination of biochemical and molecular assays. In a few LSDs, treatment with hematopoietic stem cell transplantation, enzyme replacement or substrate reduction therapy is available. Symptomatic and palliative measure may enhance quality of life for both treatable and currently untreatable cases. Genetic counseling is important, so patients and their families can be informed of reproductive risks, disease prognosis and therapeutic options. Investigations of underlying disease mechanisms are enhancing knowledge about rare diseases, but also other more common medical conditions, on account of potential convergent disease pathways.

Gaucher disease: the metabolic defect, pathophysiology, phenotypes and natural history

Gaucher disease (GD), a prototype lysosomal storage disorder, results from inherited deficiency of lysosomal glucocerebrosidase due to biallelic mutations in GBA. The result is widespread accumulation of macrophages engorged with predominantly lysosomal glucocerebroside. A complex multisystem phenotype arises involving the liver, spleen, bone marrow and occasionally the lungs in type 1 Gaucher disease; in neuronopathic fulminant type 2 and chronic type 3 disease there is in addition progressive neurodegenerative disease. Manifestations of Gaucher disease type 1 (GD1) include hepatosplenomegaly, cytopenia, a complex pattern of bone involvement with avascular osteonecrosis (AVN), osteoporosis, fractures and lytic lesions. Enzyme replacement therapy became the standard of care in 1991, and this has transformed the natural history of GD1. This article reviews the clinical phenotypes of GD, diagnosis, pathophysiology and its natural history. A subsequent chapter discusses the treatment options.

Cholelithiasis in a patient with type 2 Gaucher disease

Gaucher disease is an autosomal recessively inherited lysosomal storage disease in which a deficiency of glucocerebrosidase is associated with the accumulation of glucocerebroside in reticuloendothelial cells. Clinically, 3 types of Gaucher disease have been defined on the basis of the presence or absence of neurological symptoms. The frequency of gallbladder involvement is reportedly greater in patients with type 1 Gaucher disease than in healthy persons. We report a case of recurrent cholelithiasis and liver failure in a patient with type 2 Gaucher disease who showed severe progressive neurological involvement.

Gaucher disease

Gaucher disease is the commonest lysosomal storage disease seen in India and worldwide. It should be considered in any child or adult with an unexplained splenohepatomegaly and cytopenia which are seen in the three types of Gaucher disease. Type 1 is the non-neuronopathic form and type 2 and 3 are the neuronopathic forms. Type 2 is a more severe neuronopathic form leading to mortality by 2 years of age. Definitive diagnosis is made by a blood test-the glucocerebrosidase assay. There is no role for histological examination of the bone marrow, liver or spleen for diagnosis of the disease. Molecular studies for mutations are useful for confirming diagnosis, screening family members and prognosticating the disease. A splenectomy should not be performed except for palliation or when there is no response to enzyme replacement treatment or no possibility of getting any definitive treatment. Splenectomy may worsen skeletal and lung manifestations in Gaucher disease. Enzyme replacement therapy (ERT) has completely revolutionized the prognosis and is now the standard of care for patients with this disease. Best results are seen in type 1 disease with good resolution of splenohepatomegaly, cytopenia and bone symptoms. Neurological symptoms in type 3 disease need supportive care. ERT is of no benefit in type 2 disease. Monitoring of patients on ERT involves evaluation of growth, blood counts, liver and spleen size and biomarkers such as chitotriosidase which reflect the disease burden. Therapy with ERT is very expensive and though patients in India have so far got the drug through a charitable access programme, there is a need for the government to facilitate access to treatment for this potentially curable disease. Bone marrow transplantation is an inferior option but may be considered when access to expensive ERT is not possible.

Gaucher disease: a diagnostic challenge for internists

Gaucher disease (GD), the most common inherited lysosomal storage disorder, is a multiorgan disease due to an autosomal recessive defect of the gene encoding glucocerebrosidase enzyme, responsible for the accumulation of glucosylceramide (glucocerebroside) into reticuloendothelial cells, particularly in the liver, spleen and bone marrow. GD is a clinically heterogeneous disorder and it is conventionally classified in type 1 (non-neuronopathic disease), types 2 and 3 (acute and chronic neuronopathic disease, respectively). Features of clinical presentation and organ involvement as well as age, at presentation are highly variable among affected patients. Splenomegaly and/or thrombocytopenia are the most common presenting features either as incidental findings during routine blood count or physical examination. Other possible clinical manifestations can be hepatomegaly with abnormal liver function tests, bone pain often associated with skeletal complications (pathological fractures, avascular necrosis, osteopenia), pulmonary hypertension and, in neuronopathic forms, neurological manifestations (dysfunction of eye motility, mild mental retardation, behavioural difficulties, choreoathetosis and cramp attacks). For all these reasons GD diagnosis is often a real challenge for internists. In the presence of clinical suspicion of GD, the diagnosis has to be confirmed measuring the betaglucocerebrosidase activity in the peripheral leukocytes and by molecular analysis. Each patient needs an accurate initial multisystemic assessment, staging the damage of all the possible organs involved, and the burden of the disease, followed by regular followup. The correct and early diagnosis permits to treat patients properly, avoiding the complications of the disease.

Gaucher disease and malignancy: a model for cancer pathogenesis in an inborn error of metabolism

Clinical observations spanning almost half a century have demonstrated a consistent association of type 1 Gaucher disease (GD1) and cancers. However, the cellular and molecular bases of the association are not understood. Gaucher disease (GD) is a lysosomal storage disorder due to an inherited deficiency of acid β-glucosidase that underlies the accumulation of glucosylceramide in lysosomes of mononuclear phagocytes and immune dysregulation. The overall cancer risk is markedly increased in GD, and the determinants of malignancy in a subset of patients with GD1 are not known. The association of GD and cancer is most striking for hematological malignancies, with the risk for multiple myeloma estimated at almost 37-fold compared to the general population; some studies have also suggested increased cancer risk for non-hematological malignancies. There is no association of overall severity of GD to risk of cancer, although there is an increased prevalence of splenectomy among patients exhibiting the GD/cancer phenotype. Moreover, there appears to be an increased incidence of multiple consecutive cancers in individual patients. Several factors could contribute to cancer development in GD, including polarization of macrophages to the alternatively activated phenotype, chronic inflammation, chronic B-cell stimulation, splenectomy, hyperferritinemia, lysosomal dysfunction, and endoplasmic reticulum stress. Recent studies have highlighted T-cell dysfunction and modifier genes contributing to an increased cancer risk in GD. Macrophage-targeted enzyme replacement therapy (ERT) reverses systemic features of GD1; while cancer risk appears to be reduced in the era of ERT, it is not known whether this is a direct effect of therapy. Delineation of the mechanisms underlying the increased cancer risk in GD will provide additional novel insights into the role of lipids and macrophages in cancer pathogenesis and, moreover, have the potential to reveal novel therapeutic targets.

Dynamic changes of lipid profile in Romanian patients with Gaucher disease type 1 under enzyme replacement therapy: a prospective study

BACKGROUND

Dyslipidemia in Gaucher disease includes reduced total, low-density lipoprotein (LDL)-, and high-density lipoprotein (HDL)-cholesterol (C). No prospective analysis of lipid profile changes in treatment-naïve patients under enzyme replacement therapy (ERT) is available.

METHODS

We analyzed lipid profile changes during ERT in a prospective controlled manner. Twelve treatment-naïve patients, Gaucher disease type 1 (GD1), 29.5 ± 12.9 years, 4M/8F. Diagnosis was made by enzymatic measurement and mutational analysis. Total-, LDL-, and HDL-C, triglycerides (TG), and LDL subfractions were assessed before the start of ERT with imiglucerase and biannually for 3 years. Patients were matched with healthy controls before and after 3 years of ERT.

RESULTS

At baseline, we found severely reduced HDL-C concentrations (23.6 ± 5.4 mg/dl) and enhanced LDL/HDL ratios (3.1 ± 0.7). HDL-C increased after 6 months (29.2 ± 5.7, p = 0.023), LDL/HDL ratio decreased after 30 months (2.5 ± 0.5, p = 0.039). TG, even not consistently enhanced at baseline (128 ± 31.3 mg/dl), yet higher than in controls (p < 0.001), decreased after 18 months, being comparable with controls after 3 years of ERT. Small, dense LDL (mg/dl) increased continuously without significant difference to controls. After 3 years of ERT, only reduced HDL-C concentrations persisted as a potentially atherogenic alteration; however, mean concentrations markedly improved (42.9 ± 8.3 mg/dl, p < 0.001). Lipid parameters correlated with six markers of disease severity.

CONCLUSIONS

This is the first prospective controlled study regarding lipid profile dynamics during ERT (glucocerebrosidase) in initially treatment-naïve GD1 patients. The most important changes were reduced HDL-C and enhanced LDL/HDL ratio. Their dynamics during ERT and correlations with markers of disease activity suggest that they can be considered markers of disease severity and follow-up in Gaucher patients under treatment.

Gaucher disease

Gaucher disease is an autosomal recessive condition due to glucocerebrosidase deficiency responsible for the lysosomal accumulation of glucosylceramide, a complex lipid derived from cell membranes, mainly in macrophages. It is due to mutations mostly in the GBA gene, although saposine C deficiency is due to mutations in the PSAP gene. It encompasses an extremely heterogeneous spectrum of clinical involvement from the fetus to adulthood. Splenomegaly, blood cytopenia, and bone involvement are the main manifestations of Gaucher disease, but nervous system degeneration is observed in about 5-10% of patients. The accumulation in neurons of glucosylceramide and its derivative, psychosine, are thought to underlie neuronal dysfunction and death, although Gaucher cells that mostly accumulate such substances are mainly macrophages. Enzyme replacement therapy dramatically improves the outcome of patients because of its extreme efficacy in the treatment of the systemic involvement. However, it has only limited effects on most neurological signs.

Imiglucerase in the treatment of Gaucher disease: a history and perspective

The scientific and therapeutic development of imiglucerase (Cerezyme(®)) by the Genzyme Corporation is a paradigm case for a critical examination of current trends in biotechnology. In this article the authors argue that contemporary interest in treatments for rare diseases by major pharmaceutical companies stems in large part from an exception among rarities: the astonishing commercial success of Cerezyme. The fortunes of the Genzyme Corporation, latterly acquired by global giant Sanofi SA, were founded on the evolution of a blockbuster therapy for a single but, as it turns out, propitious ultra-orphan disorder: Gaucher disease.

How I treat Gaucher disease

This review presents a cohesive approach to treating patients with Gaucher disease. The spectrum of the clinical presentation of the disease is broad, yet heretofore there was only one disease-specific treatment. In the past 2 years, a global shortage of this product has resulted in reassessment of the “one enzyme–one disease–one therapy” mantra. It has also showcased the multiple levels that engage the patient, the treating physician, and the third-party insurer in providing adequate treatment to all symptomatic patients. The key points summarizing the way I manage my patients include accurate enzymatic diagnosis with mutation analysis (for some prognostication and better carrier detection in the family), a detailed follow-up every 6-12 months (with an option to see consultants and attention to comorbidities), and initiation of enzyme replacement therapy according to symptoms or deterioration in clinically significant features or both. I do not treat patients with very mild disease, but I consider presymptomatic therapy for patients at risk, including young women with poor obstetric history. I prefer the minimal-effective dose rather than the maximally tolerated dose, and when the difference between high-dose and lower-dose regimens is (merely statistically significant but) clinically meaningless, minimizing the burden on society by advocating less-expensive treatments is ethically justified.

Evaluation of high density lipoprotein as a circulating biomarker of Gaucher disease activity

Circulating biomarkers are important surrogates for monitoring disease activity in type I Gaucher disease (GD1). We and others have reported low high-density lipoprotein (HDL) in GD1. We assessed HDL cholesterol as a biomarker of GD1, with respect to its correlation with indicators of disease severity and its response to imiglucerase enzyme replacement therapy (ERT). In 278 consecutively evaluated GD1 patients, we correlated HDL cholesterol, chitotriosidase, and angiotensin-converting enzyme (ACE) with indicators of disease severity. Additionally, we measured the response of these biomarkers to ERT. HDL cholesterol was negatively correlated with spleen volume, liver volume, and GD severity score index; the magnitude of this association of disease severity with HDL cholesterol was similar to that for ACE and for chitotriosidase. Within individual patients monitored over many years, there was a strikingly strong correlation of HDL with liver and spleen volumes; there was a similarly strong correlation of chitotriosidase and ACE with disease severity in individual patients monitored serially over many years (chitotriosidase r = 0.96 to 0.98, ACE r = 0.88 to 0.94, and HDL r = -0.84 to -0.94, p < 0.001). ERT for 3 years resulted in a striking increase of HDL while serum levels of chitotriosidase and ACE decreased. Our results reveal markedly low HDL cholesterol in untreated GD1, a correlation with indicators of disease severity in GD1, and a rise towards normal after ERT. These findings suggest HDL cholesterol merits inclusion within the "biomarker basket" for monitoring of patients with GD1.

Glucocerebrosidase gene-deficient mouse recapitulates Gaucher disease displaying cellular and molecular dysregulation beyond the macrophage

In nonneuronopathic type 1 Gaucher disease (GD1), mutations in the glucocerebrosidase gene (GBA1) gene result in glucocerebrosidase deficiency and the accumulation of its substrate, glucocerebroside (GL-1), in the lysosomes of mononuclear phagocytes. This prevailing macrophage-centric view, however, does not explain emerging aspects of the disease, including malignancy, autoimmune disease, Parkinson disease, and osteoporosis. We conditionally deleted the GBA1 gene in hematopoietic and mesenchymal cell lineages using an Mx1 promoter. Although this mouse fully recapitulated human GD1, cytokine measurements, microarray analysis, and cellular immunophenotyping together revealed widespread dysfunction not only of macrophages, but also of thymic T cells, dendritic cells, and osteoblasts. The severe osteoporosis was caused by a defect in osteoblastic bone formation arising from an inhibitory effect of the accumulated lipids LysoGL-1 and GL-1 on protein kinase C. This study provides direct evidence for the involvement in GD1 of multiple cell lineages, suggesting that cells other than macrophages may be worthwhile therapeutic targets.