Diagnosis of Lysosomal Storage Disorders: Gaucher Disease (original) (raw)
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International Journal of Molecular Sciences
Gaucher disease (GD) is a lysosomal storage disorder that responds well to enzyme replacement therapy (ERT). Certain laboratory parameters, including blood concentration of glucosylsphingosine (Lyso-Gb1), the lyso-derivate of the common glycolipid glucocerebroside, correlate with clinical improvement and are therefore considered candidate-monitoring biomarkers. Whether they can indicate a reduction or loss of treatment efficiency, however, has not been systematically addressed for obvious reasons. We established and validated measurement of Lyso-Gb1 from dried blood spots (DBSs) by mass spectrometry. We then characterized the assay’s longitudinal performance in 19 stably ERT-treated GD patients by dense monitoring over a 3-year period. The observed level of fluctuation was accounted for in the subsequent development of a unifying data normalization concept. The resulting approach was eventually applied to data from Lyso-Gb1 measurements after an involuntary treatment break for all 1...
Enzyme Augmentation in Moderate to Life-Threatening Gaucher Disease
Pediatric Research, 1992
Gaucher disease type 1 (GD type 1) is the most prevalent lysosomal storage disease and has its highest frequency in the Ashkenazi Jewish population. Deficiency of the enzyme, acid 8-glucosidase, results in the deposition of glucocerebroside primarily in macrophages. The accumulation of such "Gaucher cells" leads to visceromegaly, hepatic and bone marrow dysfunction, hypersplenism, and bony disease. Eleven GD type 1 patients, ages 4-52 y, with moderate to life-threatening manifestations, received 6-12 mo of enzyme augmentation with a macrophage-targeted acid 8-glucosidase preparation.
Proceedings of the National Academy of Sciences, 1990
Enzyme replacement has been under consideration as a therapeutic strategy for patients with Gaucher disease for more than two decades. Previous studies indicated that single injections of purified glucocerebrosidase reduced the amount of storage material in the liver. It was important to determine whether administration of exogenous enzyme on a regular basis would be of clinical benefit. We report here that weekly i.v. infusions of a macrophage-targeted preparation of human placental glucocerebrosidase in a child with type 1 Gaucher disease increased hemoglobin from 6.9 +/- 0.8 g/dl (+/- 1 SD) to 10.2 +/- 0.4 g/dl (+/- 1 SD) over a 20-week period. The platelet count also increased from a pretreatment value of 30,000 +/- 7000/mm3 (+/- 1 SD) to 54,000 +/- 11,000/mm3 (+/- 1 SD). Phagocytic activity in the spleen decreased during the period of enzyme administration, and there was radiographic evidence of skeletal improvement. These observations document objective clinical responses to e...
Basic & clinical pharmacology & toxicology, 2018
The quantification of enzyme activity in the patient treated with enzyme replacement therapy (ERT) has been suggested as a tool for dosage individualisation, so we conducted a study to evaluate the relationship between glucocerebrosidase activity and clinical response in patients with Gaucher disease type I (GD1) to ERT. The study included patients diagnosed with GD1, who were being treated with ERT, and healthy individuals. Markers based on glucocerebrosidase activity measurement in patients' leukocytes were studied: enzyme activity at 15 min. post-infusion (Act) reflects the amount of enzyme that is distributed in the body post ERT infusion, and accumulated glucocerebrosidase activity during ERT infusion (Act) indicates the total drug exposure during infusion. The clinical response was evaluated based on criteria established by Pastores et al. and Gaucher Severity Score Index. Statistical analysis included ROC analysis and area-under-curve test. Actand Actwere found to be mode...
Clinica Chimica Acta, 2005
Background: Gaucher's disease (GD) is a disorder caused by the deficiency of lysosomal h-glucosidase, an enzyme that participates in the degradation of glycosphingolipids. Deficiency of this enzyme results in the storage of glucocerebrosides in lysosomes of macrophage. No studies are available in the literature comparing biochemical and kinetic behavior of this enzyme in leukocytes and fibroblasts from normal individuals, obligate heterozygotes and patients with GD. Methods: The behavior of h-glu in terms of optimum pH, heat stability, Km and Vmax in leukocytes from patients with GD and obligated heterozygotes with different genotypes and normal individuals were characterized. Results: Optimum pH was similar in all groups analyzed. In terms of Km and Vmax, several differences among heterozygotes and homozygotes groups and among these groups and normal enzyme were observed. Enzyme from all groups were inactivated when preincubated at 60 8C, but some enzymes were more stable than other. Results showed a different behavior of the enzyme in the 3 groups under analysis. Such behavior varied according to individual mutation. Conclusions: The catalytic gradient presented by h-glu allowed the correlation of N370S mutation-which presented more stable biochemical properties-with the non-neurological clinical condition of the disease and the catalytically less stable mutation (D409H), with the neurological clinical condition of GD. This study contributes to a better understanding of the repercussion of the different mutations on the protein function, thus allowing to predict the severity of such complex metabolic disorder and to anticipate the most appropriate intervention for each case specifically. D
Gaucher’s Disease in a 2 Years Old Child: A Case Report
American Journal of Pediatrics, 2020
Gaucher's Disease (GD) is an autosomal recessive systemic lysosomal storage disorder, characterized by glucocerebroside deposition in cells of macrophage-monocyte system as result of deficiency in lysosomal β-glycosidase (glucocerebrosidase). GD is a rare genetic disorder. It is the most common among the lysosomal storage disorders. Hereby we report a 2-year-old male presented with weakness, pallor and gradually enlarge belly. In the beginning the diagnosis was suspected acute leukemia, an abnormality in hematooncology due to bisitopenia and organomegaly. Therefore patient was gone through Bone Marrow Aspiration (BMA) to confirm the diagnosis, however the results of 3 times BMA were not align with acute leukemia. Moreover the history and clinical examination pointed to be a lipid storage disease. Finally patient was diagnosed as GD after the smear of BMA showed foam cell. In addition the confirmation of Gaucher's disease was performed by measurement of glucocerebrosidase level, which resulted low in β-Glukosidase 0.97 uM/hr (normal level > 1.8 uM/hr). Therefore we emphasize the importance of early recognition by clinical manifestation and histological findings. GD should be considered as differential diagnosis of children with unexplained hepatosplenomegaly. Patients suspected with acute leukemia should be examined for possibility of GD from bone marrow smear. Furthermore, early recognition of GD would lead to safe and effective treatment with enzyme replacement which can decrease morbidity.
Cellular Uptake of Glucocerebrosidase in Gaucher Patients Receiving Enzyme Replacement Treatment
Clinical Pharmacokinetics, 2016
Background Enzyme replacement therapy (ERT) is currently the standard treatment for patients with Gaucher disease type I (GD1), but the pharmacokinetics have hardly been studied. This study aimed to quantify in vivo enzyme activity in peripheral leukocytes from patients receiving long-term treatment with imiglucerase or velaglucerase for GD1, and set out to assess the process of enzymatic uptake by peripheral leukocytes. Methods A prospective semi-experimental study was conducted. Four time points for blood withdrawal were planned per patient to quantify the intra-leukocyte enzymatic activity. In order to assess the uptake process, the rate of enzyme uptake by leukocytes (Rupt) and the rate of enzyme disappearance from the plasma (Rdis) were estimated. Results Eight GD1 patients were included. Intra-leukocyte activity was 24.31 mU/mL [standard deviation (SD) 6.32 mU/mL; coefficient of variation (CV) 25.96 %] at baseline and 27.14 mU/mL (SD 6.96 mU/mL; CV 25.65 %) at 15 min post-perfusion. The relationships with the administered dose were linear. The Rupt value was 37.73 mU/mL/min [95 % confidence interval (CI) 25.63-49.84] and showed a linear correlation with the administered enzyme dose (p \ 0.05), and the Rdis value was 189.43 mU/mL/min (95 % CI 80.31-298.55) and also showed a linear correlation with the dose (p \ 0.05). Conclusion This was the first in vivo study to quantify the accumulated enzymatic activity in patients receiving ERT for GD1. It showed that intra-leukocyte activity at baseline and at 15 min post-perfusion could be used as a possible marker for therapeutic individualization in patients receiving ERT for GD1. Key Points Quantification of enzymatic activity in leukocytes could be used as a marker for therapeutic individualization in patients receiving enzyme replacement therapy for Gaucher disease type I. The rate of enzyme disappearance from the plasma and the rate of enzyme uptake by leukocytes show a linear correlation with the administered enzyme dose and high inter-patient variability. After administration of imiglucerase or velaglucerase, the leukocyte enzymatic activity values and rates of internalization by leukocytes are similar.