Identification and use of biomarkers in Gaucher disease and other lysosomal storage diseases (original) (raw)

Elevated plasma chitotriosidase activity in various lysosomal storage disorders

Journal of Inherited Metabolic Disease, 1995

Recently a striking elevation of the activity of chitotriosidase, an endo ~glucosaminidase distinct from lysozyme, was found in plasma from patients with Gaucher type I disease (McKusick 230800). Plasma chitotriosidase originates from activated macrophages and this elevation is secondary to the basic defect in Gaucher disease. To investigate the specificity of this phenomenon, we have investigated 24 different lysosomal storage diseases. In 11 different diseases increased chitotriosidase activity in plasma was found (in 28% of the patients). None of these diseases showed elevations as high as in Gaucher disease. Chitotriosidase was not significantly elevated in plasma from 20 different non-lysosomal enzymopathies or in plasma from patients with infectious diseases associated with hepatomegaly. The results show that marked elevation of chitotriosidase activity in plasma appears to be specific for Gaucher disease. The data further suggest that elevated levels of chitotriosidase activity in plasma from patients with unexplained diseases may be indicative for a lysosomal disorder.

Marked elevation of plasma chitotriosidase activity. A novel hallmark of Gaucher disease

Journal of Clinical Investigation, 1994

Gaucher disease (GD; glucosylceramidosis) is caused by a deficient activity of the enzyme glucocerebrosidase (GC). Clinical manifestations are highly variable and cannot be predicted accurately on the basis of the properties of mutant GC. Analysis of secondary abnormalities, such as elevated plasma levels of some hydrolases, may help to increase insight into the complicated pathophysiology of the disease and could also provide useful disease markers. The recent availability of enzyme supplementation therapy for GD increases the need for markers as early predictors of the efficacy of treatment. We report the finding of a very marked increase in chitotriosidase activity in plasma of30 of 32 symptomatic type 1 GD patients studied: the median activity being > 600 times the median value in plasma of healthy volunteers. In three GC-deficient individuals without clinical symptoms, only slight increases were noted. Chitotriosidase activity was absent in plasma of three control subjects and two patients. During enzyme supplementation therapy, chitotriosidase activity declined dramatically. We conclude that plasma chitotriosidase levels can serve as a new diagnostic hallmark of GD and should prove to be useful in assessing whether clinical manifestations of GD are present and for monitoring the efficacy of therapeutic intervention. (J. Clin. Invest. 1994.

Diagnosis of Lysosomal Storage Disorders: Gaucher Disease

Current Protocols in Human Genetics, 2001

Gaucher Disease (GD) is a progressive lysosomal storage disorder caused by deficiency of glucocerebrosidase (GBA). The clinical phenotype follows a spectrum ranging from severe early-onset to milder late-onset disease. The absence of neurological involvement defines GD type I, whereas neuronopathic features define GD type II and III. Early diagnosis may be important for timely initiation of enzyme replacement therapy to prevent disease complications, although the enzyme does not cross the blood brain barrier. Diagnosis of GD can be readily achieved by analysis of GBA in leukocytes, fibroblasts, and/or dried blood spots using fluorometric, microfluidic or mass spectrometry-based assays. Low GBA activities are typically confirmed through molecular analysis of the GBA gene. GBA analysis in dried blood spots may be attractive for high-throughput screening of at-risk individuals and/or newborn infants. The method detailed in this unit is based on GBA analysis by tandem mass spectrometry following incubation of dried blood spots with the GBA-specific substrate D-glucosyl-β1-1-N-dodecanoyl-D-erythrosphingosine [C12-glucocerebroside (C 36 H 69 NO 8)] and internal standard N-myristoyl-Derythro-sphingosine [C14-ceramide (C 32 H 63 NO 3)]. GBA activities in more than 2,000 newborn infants showed a mean of 22.0 ± 13.8 μmol/hr/liter (median: 19.9 μmol/hr/liter; 95% CI: 21.41-22.59 μmol/hr/liter). GBA activities in an adult population (n >1,200) showed generally lower enzyme activities than newborns, with a mean of 9.87 ± 9.35 μmol/hr/liter (median: 8.06 μmol/hr/liter). GBA activities in ten adult patients with confirmed GD were less than 4.2 μmol/hr/liter and in seven infants and children with GD less than 1.24 μmol/hr/liter. This method is robust, sensitive, and suitable for high-throughput analysis of hundreds of samples.

Biomarkers in the diagnosis of lysosomal storage disorders: proteins, lipids, and inhibodies

Journal of Inherited Metabolic Disease, 2011

A biomarker is an analyte indicating the presence of a biological process linked to the clinical manifestations and outcome of a particular disease. In the case of lysosomal storage disorders (LSDs), primary and secondary accumulating metabolites or proteins specifically secreted by storage cells are good candidates for biomarkers. Clinical applications of biomarkers are found in improved diagnosis, monitoring disease progression, and assessing therapeutic correction. These are illustrated by reviewing the discovery and use of biomarkers for Gaucher disease and Fabry disease. In addition, recently developed chemical tools allowing specific visualization of enzymatically active lysosomal glucocerebrosidase are described. Such probes, coined inhibodies, offer entirely new possibilities for more sophisticated molecular diagnosis, enzyme replacement therapy monitoring, and fundamental research.

Critical assessment of chitotriosidase analysis in the rational laboratory diagnosis of children with Gaucher disease and Niemann–Pick disease type A/B and C

Journal of Inherited Metabolic Disease, 2006

Laboratory diagnosis of lysosomal storage disorders, especially sphingomyelinase deficiency (Niemann-Pick disease type A/B) and Niemann-Pick disease type C (NPC) can be challenging. We therefore aimed to analyse the feasibility of first-step screening with specific chitotriosidase cut-off values in children ≤10 years of age with visceral organomegaly (hepatomegaly, splenomegaly, or hepatosplenomegaly) in whom a storage disorder was suspected. We conducted a retrospective, cross-sectional, referral, single-centre study to assess diagnostic test properties in 106 individuals. Median chitotriosidase activity was 12 655 nmol/h per ml (interquartile range 4693-20982) in Gaucher disease (GD); 780 (465-1298) in SMD (sphingomyelinase deficiency); 925 (319-1215) in NPC and 50 (29-54) in patients with miscellaneous diseases. To restrict the differential diagnosis to GD, SMD or NPC, chitotriosidase activity above 200 nmol/h per ml had a sensitivity of 96%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 95%. For GD alone, chitotriosidase activity above 4000 nmol/h per ml had a sensitivity of 77%, specificity of 100%, PPV of 100% and NPV of 92%. Of the 44 patients analysed, 4.5% were homozygous and 36.4% heterozygous for chitotriosidase gene duplication. Adjusting for the chitotriosidase genotype, chitotriosidase activities were higher in GD type III than in GD type I. We conclude that, in the above setting, the degree of elevation of chitotriosidase activity can be applied to increase the likelihood of GD, SMD, or NPC and guide the choice of the appropriate confirmatory assay.

Twenty- five years of biochemical diagnosis of Gaucher disease: the Egyptian experience

Heliyon, 2019

Background: Gaucher disease is a rare multi-systemic metabolic disorder resulting from the deficiency of acid β-glucosidase activity, with consequent accumulation of glucocerebroside. Less than 15% of mean normal acid β-glucosidase activity in leukocytes is the gold standard for the diagnosis of Gaucher disease, and is generally supplemented by a massive elevation in chitotriosidase activity. We report here our experience in the biochemical diagnosis of Gaucher disease by showing the heterogeneity of the activity of enzymes over 25 years from 1993-2017, through the analysis of 5128 clinically suspected Gaucher disease cases referred to the Biochemical Genetics Department, National Research Centre, as the main reference lab in Egypt for the diagnosis of Inherited Metabolic Disorders. Methods: Acid β-glucosidase and chitotriosidase activities were measured in all referred cases. Sphinogmylinase activity was estimated for all cases with normal β-glucosidase activity and moderate elevation of chitotriosidase. Results: Out of the 5128 suspected cases, 882 (17%) showed a deficiency in acid β-glucosidase activity, accompanied by a raised chitotriosidase activity, ranges (213-66700 umol/l/h) and mean (7255 umol/l/h). Deficient chitotriosidase activity was found in 9 patients (1%) with low β-glucosidase. 451 cases were diagnosed with acid sphingomyelinase deficiency patients (8.8%). Conclusion: Other biochemical markers are needed in addition to chitotriosidase for the diagnosis and follow up. Molecular testing was done to a relatively small number but needs to be done to all diagnosed patients as many mutations are known to predict the course of the disease.