Evaluation of alpha-Iduronidase in Dried Blood Spots is an Accurate Tool for Mucopolysaccharidosis I Diagnosis

Evaluation of alpha-Iduronidase in Dried Blood Spots is an Accurate Tool for Mucopolysaccharidosis I Diagnosis

Author Mueller, Karen B. Autor UNIFESP Google Scholar
Pereira, Vanessa G. Autor UNIFESP Google Scholar
Martins, Ana M. Autor UNIFESP Google Scholar
D'Almeida, Vania Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract Background: Mucopolysaccharidosis type I (MPS I) is caused by a deficiency of the alpha-L-iduronidase (IDUA), which leads to the accumulation of glycosaminoglycans in lysosomes. MPS I patients present a spectrum ranging from a severe to an attenuated phenotype. Once clinical suspicion is present, diagnosis of MPS I can be performed by enzyme activity determination and or molecular analysis. the aim of this study was to establish a reference interval value to IDUA activity using a dried blood spots (DBS) assay and to evaluate whether this assay could be a secure tool to diagnose MPS I patients. Results: IDUA activity range on HV DBS samples were 1.40-7.78 mu mol/l blood/hr. Regarding the validation group, 11 of the 36 individuals clinically suspected of MPS I had the diagnosis confirmed by DBS and reference assay (leukocytes). When we considered the new proposed cutoff value of 1.5 mu mol/l blood/hr, the sensitivity, specificity, and predictive values were 100%. Conclusions: Our results strongly suggest that the determination of IDUA activity using a DBS assay is a secure tool for MPS I diagnosis. However, it is extremely important to assure that all recommendations for collection, transport, and storage are correctly followed to guarantee the quality of the samples. J. Clin. Lab. Anal. 25: 251-254, 2011. (C) 2011 Wiley-Liss, Inc.
Keywords lysosomal storage disease
enzyme activity
fluorimetric assay
dried blood spots
mucopolysaccharidosis type I
Language English
Sponsor Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Grant number CNPq: 501248/2005-6
Date 2011-01-01
Published in Journal of Clinical Laboratory Analysis. Malden: Wiley-Blackwell, v. 25, n. 4, p. 251-254, 2011.
ISSN 0887-8013 (Sherpa/Romeo, impact factor)
Publisher Wiley-Blackwell
Extent 251-254
Origin http://dx.doi.org/10.1002/jcla.20468
Access rights Closed access
Type Article
Web of Science ID WOS:000293586600006
URI http://repositorio.unifesp.br/handle/11600/33252

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