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Gaucher disease (GD) is a disorder of glycosphingolipid metabolism caused by deficiency of lysosomal glucocerebrosidase (GlcCerase) activity, due to conformationally or functionally defective variants, resulting in progressive deposition of glycosylceramide in macrophages. The glucose analogue, N-butyldeoxynojirimycin (NB-DNJ, miglustat), is an inhibitor of the ceramide-specific glycosyltransferase, which catalyzes the first step of glycosphingolipid biosynthesis and is currently approved for the oral treatment of type 1 GD. In a previous work, we found a GlcCerase activity increase in cell cultures in the presence of NB-DNJ, which could imply that this compound is not only a substrate reducer but also a pharmacological chaperone or inhibitor for GlcCerase degradation. In this work we compare imiglucerase (the enzyme currently used for replacement therapy) and velaglucerase alfa (a novel therapeutic enzyme form) in terms of conformational stability and enzymatic activity, as well as the effect of NB-DNJ on them. The interaction between these enzymes and NB-DNJ was studied by isothermal titration calorimetry. Our results reveal that, although velaglucerase alfa and imiglucerase exhibit very similar activity profiles, velaglucerase alfa shows higher in vitro thermal stability and is less prone to aggregation/precipitation, which could be advantageous for storage and clinical administration. In addition, we show that at neutral pH NB-DNJ binds to and enhances the stability of both enzymes, while at mildly acidic lysosomal conditions it does not bind to them. These results support the potential role of NB-DNJ as a pharmacological chaperone, susceptible of being part of pharmaceutical formulation or combination therapy for GD in the future.

Recently, an acute restriction of imiglucerase has occurred as a result of viral contamination and manufacturing problems. A position statement from the European Working Group for Gaucher Disease and European Gaucher Alliance established a set of key recommendations for identifying and monitoring at-risk patients. In Spain, a profile of the shortage situation was obtained through follow-up of patients with Gaucher disease (GD) and compliance with the therapy recommendations. Here we describe a group of patients, with modified doses of imiglucerase, during the shortage. Fifty adult GD1 patients (25 males/25 females), previously on ERT, were analysed before and after the 6-month shortage. The mean age was 45.3 ± 15.3 years (range: 18-84). The mean Severity Score Index at diagnosis was 8.7 ± 3.8 (range: 3-19); 20% of patients were splenectomized; and 78% had bone disease. During the shortage, 23 patients (46%) discontinued therapy; as complications in this group only one patient suffered a bone crisis and another anaemia (Hb <10.0 g/dL). The mean reduction of haemoglobin level (-2.7%) and platelet counts (-5.4%) were non-significant. Chitotriosidase (CT) activity was increased 135% (p<0.03) and CCL18/PARC 8.2% (p<0.08) in this group. Imiglucerase was reduced by 50% in 17 patients (34%) in this group, seven patients (41.0%) suffered bone pain, three of them true bone crisis and four (23.5%) required support therapy. The mean reduction of haemoglobin (-2.8%) and platelet counts (-10.7%), CT activity was increased 48.2% (p<0.03) and no changes were observed in CCL18/PARC concentration. In both groups no significant changes in visceral size were observed. In 3 patients (6%), imiglucerase was reduced 75% and 7 patients (14%) needed to switch to another ERT (4 patients) or miglustat (3 patients) due to a restart of symptomatic disease. In Spain the 6 first months shortage of imiglucerase have produced a 20% incidence of bone pain, one case of anaemia, and a significant increase in CT activity. Fourteen percent of patients had to switch to another therapy. No significant changes in blood counts, visceral volumes and CCL18/PARC concentration were observed., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Gaucher disease is the first lysosomal disorder for which clinically effective enzyme replacement therapy has been introduced. Lifelong treatment with imiglucerase, the recombinant glucocerebrosidase manufactured by the Genzyme Corporation (MA, USA), is administered intravenously - usually at biweekly intervals. An acute shortage of imiglucerase (to 20% of prior global supply) has occurred as a result of viral contamination of the production facility; production was halted, and a full supply of imiglucerase is not anticipated until January 2010. An urgent meeting of physicians, researchers, and patients was convened through the agency of the European Working Group for Gaucher Disease; this was instigated by patients internationally represented by the European Gaucher Alliance. Here we present a position statement based on the findings of the group, with key recommendations about identification and monitoring of at-risk patients threatened by the abrupt withdrawal of treatment, the equitable distribution of residual imiglucerase - and access to alternative treatments including those that have completed phase III clinical trials but have not yet been licensed., (Copyright 2009 Elsevier Inc. All rights reserved.)

Purpose: Gaucher disease (GD) is an autosomal recessive lysosomal disorder caused by a deficiency of glucocerebrosidase. The neurologic manifestations of GD patients have to date been refractory to any treatment approach. We present a report of a neuronopathic GD patient whose myoclonic epilepsy improved after combination therapy with imiglucerase and miglustat., Methods: In an adult type 3 GD patient who, despite good visceral and analytic response to ERT, developed progressive neurologic deterioration with marked myoclonic epilepsy and dystonia, we added miglustat to the enzyme-replacement therapy., Results: After 2 years of combined miglustat (200 mg, 3 t.i.d.) and imiglucerase (60 IU/kg every 2 weeks), generalized tonic-clonic seizures decreased, speech improved, and the general neurologic clinical picture improved markedly. The EEG showed a reduction in focal and generalized paroxysmal discharges. No significant adverse effects were observed., Conclusions: Combined imiglucerase and miglustat therapy may be beneficial for some neuronopathic forms of GD.

Mutations in the glucocerebrosidase (GBA) gene cause Gaucher disease (GD). The aim of this study was to characterise the GBA mutations and analyze genotype/phenotype relationships in 193 unrelated patients from the Spanish GD Registry. We have identified 98.7% of the mutated GBA alleles, finding 56 different GBA mutations and 66 genotypes causing GD in Spain: 47 previously described mutations and 9 novel mutations (4 missense R395C, R463H, W312R and V398I, 1 nonsense R359X, 4 frameshift c.708delC, c.1214-1215delGC, c.1439-1445del7 and c.42-65del24). The most prevalent mutations were N370S and L444P, accounting for 68.7% of the mutated alleles. A wide phenotypic difference was observed within each genotypic group, and 9% of diagnosed type 1 patients developed neurological involvement including parkisonism, tremor, hypoacusia and eye movements. All of these findings indicate that there is a significant genotypic heterogeneity that explains the huge phenotypic variation among Spanish GD patients.

Short Introduction: Gaucher's disease (GD) is an autosomal recessive disease produced by mutations of the Glucocerebrosidase gene. Carriers are considered to be healthy subjects because there is no manifestation of the disease, but they show signs of macrophage disfunction. The aim of the study was to determine if GD patients and non affected carriers risk suffering other diseases when compared to healthy non-carrier relatives., Design: Epidemiologic study of historic cohorts. The fact that they have one or two mutated alleles has been considered to be the risk factor leading to other conditions (Dementia, Parkinson disease, Ischemic stroke, Ischemic heart disease, Non rheumatic valvular disease, Cancer hematological and non-hematological, Pulmonary fibrosis, Tuberculosis, Gallstones and Schizophrenia). All people, patients, carriers and healthy controls shared the same genetical background and environmental influence. - Patients and relatives enrolled on the Spanish Gaucher Disease Registry were evaluated., Statistics: For the Relative-Risk calculation the Mantel-Haenszel test was applied. Yates' correction was used when size sample was too small. A value of p <0.05 was accepted for statistical significance., Results: 370 people, from 79 different families, were surveyed. We received evaluable information from 45 families (56%), totalling 258 people (69%): 59 healthy subjects (Mean age 32. 20, RANGE: 10-85; M 57.63%/F 42.37%), 132 carriers (Mean age 35.91, RANGE: 1-79; M 56.82%/F 43.18%) and 67 patients (Mean age 32.16, Range: 1-76; M 44.78%/F 55.22%. - Relative Risk of suffering any disease with regard to Gaucher's status: Patient vs Healthy 9.69 (95% Confidence interval [CI] 2.00-63.99; p 0.0006). Patient vs Carrier 3.74 (CI 1.53-9.27; p 0.001); Carrier vs Healthy 2.59 (CI 0. 52-12.50; p 0.21). Relative Risk of suffering any disease with regard to sex was 3.96 for female patients (CI 1.01-16.75; p 0.02) and 1.34 for female carriers (CI 0.27-6.75; p = 0.68)., Conclusion: As a group, Gaucher's patients seem to have a greater risk of suffering other common unrelated diseases than carriers or healthy relatives. This excess of risk is particularly higher among female patients and can not be explained in terms of differences in age. Carrier status doesn't seem to highten the risk of suffering other diseases.

Background: Gaucher's disease is the most common lysosomal storage disorder, caused by deficiency of glucocerebrosidase resulting from homozygosity for any of several mutations of the glucocerebrosidase gene locus. Affected people have decreased concentrations of LDL cholesterol (LDL-C) and HDL cholesterol (HDL-C). We assessed the association between mutations in the glucocerebrosidase locus and hypo-alpha-lipoproteinaemia., Methods: We studied 258 people from 43 unrelated Spanish families. 57 participants were affected, 137 were non-affected carriers, and 64 were non-carriers. We determined glucocerebrosidase genotypes and measured plasmid lipids, apolipoproteins A-I, B, and E, and leucocyte glucocerebrosidase activity., Findings: The most common glucocerebrosidase mutations were N370S (45%), L444P (23%), and G377S (5%). Deletions and recombinants accounted for another 5%, and point mutations in exons 5, 6, 9, and 10 were present in 12%. Affected participants had lower LDL-C and HDL-C concentrations than non-affected carriers (p<0.001) and non-carriers (p<0.001). HDL-C values were also significantly different between the non-affected carriers and non-carriers. Mutations at this locus may account for as much as 19.5% of the genetic variability in HDL-C in the population studied., Interpretation: Heterozygosity for these mutations at the glucocerebrosidase locus does not result in clinical expression of Gaucher's disease but can decrease HDL-C concentrations. Given the high frequency of these mutations, the glucocerebrosidase locus might lead to familial low alpha-lipoproteinaemia in up to 2% of the general population and be one of the most common known genetic causes of HDL-C.