Alpha-l-iduronidase and arylsulfatase B in dried blood spots on filter paper: Biochemical parameters and time stability.

Background: The goal of this study was to assess the biochemical parameters of the enzymes α-l-iduronidase (IDUA) and arylsulfatase B (ASB), which are deficient in mucopolysaccharidosis (MPS) I and VI, respectively, in dried blood spot (DBS) samples impregnated on filter paper.

Methods And Results: The optimal pH, Km, and Vmax of IDUA and ASB in DBS are hereby presented. After these analyses, the reference values for the activities of these enzymes in DBS with cutoff of 3.

Comparing the alpha-galactosidase A biochemical properties from healthy individuals and Fabry disease patients.

Background: Due to the importance and the difficulty still present in determining the biochemical diagnosis of Fabry disease (FD), the aim of this study was to establish and compare the biochemical and kinetic properties of alpha-galactosidase A (GLA) in dried blood spots (DBS), plasma and leukocyte samples of FD patients and healthy subjects to evaluate the possible use of these parameters as an auxiliary tool in the diagnosis of this disease.

Methods: GLA activity in DBS, plasma and leukocyte samples from Fabry disease patients and healthy subjects was compared and characterized in terms of optimal pH, Km and Vmax and heat stability.

Results: A difference was observed between the Km and Vmax of FD patients and healthy controls using DBS, plasma and leukocyte samples.

Determination of the lysosomal hydrolase activity in blood collected on filter paper, an alternative to screen high risk populations.

This study aimed to determine the enzymatic activity in dried blood samples collected on filter paper (DBS) for the diagnosis of the following diseases: Fabry, Pompe, Mucopolysaccharidosis type I (MPS I) and Mucopolysaccharosis type VI (MPS VI). DBS was used for high risk patientscreening, according to clinical suspicion. Plasma, leukocytes and cultured fibroblasts were used to confirm the diagnosis when necessary.

Screening of high-risk Gaucher disease patients in Brazil using miniaturized dried blood spots and leukocyte techniques.

This study investigates the miniaturization of the screening technique using dried blood spots on filter paper (DBS) to measure GBA and CT activities, and GBA and β-galactosidase activities in leukocytes. 274 DBS from individuals with suspected GD were screened for 1.5 years.

Comparison between alpha-galactosidase A activity in blood samples collected on filter paper, leukocytes and plasma.

Objectives: To compare alpha-galactosidase A activity in dried blood spots on filter paper, plasma, and leukocytes of Fabry disease patients and healthy controls, and to develop a miniaturization approach of the techniques to measure activity using plasma and leukocytes.

Design And Methods: Blood was collected from healthy controls and Fabry disease patients. Two drops were spotted on filter paper.

Effect of sample collection, temperature and time of storage on β-galactosidase and total hexosaminidase activities in dried blood collected on filter paper.

Background: Dried blood spots (DBS) on filter paper is a valuable sampling technique in clinical chemistry, but the stability of enzymes used in the diagnosis of lysosomal storage diseases (LSDs) needs to be evaluated.

Methods: In a first experiment, blood from 20 subjects was collected using a syringe without additives and distributed into EDTA tubes, heparin tubes, and spotted on filter paper for the comparison of sampling effects. In a second experiment, blood from 30 healthy subjects was spotted on filter paper and analyzed for β-galactosidase and total hexosaminidase activities after storage of the samples at different temperatures for up to 180 days.

Influence of pre-analytical factors on α-galactosidase A, arylsulfatase B and α-glucosidase activities measured on dried blood spots on filter paper.

Objectives: To analyze the effect of blood collection and storage conditions on activity of α-galactosidase A, arylsulfatase B and α-glucosidase.

Design And Methods: Blood was collected in EDTA, heparin, or direct spotting on filter paper and stored at different temperatures (-20, 4, 25 and 37°C) and storage times (3, 10, 17 and 180 days). The influence of filter paper size was also assessed (3.