A column-switching HPLC-MS/MS method for mucopolysaccharidosis type I analysis in a multiplex assay for the simultaneous newborn screening of six lysosomal storage disorders

• Published in: Biomedical chromatography Vol. 28; no. 8; pp. 1131 - 1139
• Main Authors: Gucciardi, Antonina, Legnini, Elisa, Di Gangi, Iole Maria, Corbetta, Carlo, Tomanin, Rosella, Scarpa, Maurizio, Giordano, Giuseppe
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.08.2014
• Subjects: Case-Control Studies; Chromatography, High Pressure Liquid - methods; column-switching HPLC/MS; dried blood spot; Dried Blood Spot Testing - methods; Enzyme Assays - methods; Humans; Iduronidase - blood; Iduronidase - metabolism; Infant, Newborn; Linear Models; Lysosomal Storage Diseases - diagnosis; Lysosomal Storage Diseases - enzymology; lysosomal storage disorders; MPS I; Mucopolysaccharidosis I - diagnosis; Mucopolysaccharidosis I - enzymology; Neonatal Screening - methods; newborn screening; Reproducibility of Results; Tandem Mass Spectrometry - methods; column-switching HPLC/MS; MPS I; dried blood spot; newborn screening; lysosomal storage disorders
• ISSN: 0269-3879; 1099-0801
• DOI: 10.1002/bmc.3133

ABSTRACT Lysosomal storage disorders comprise a group of rare genetic diseases in which a deficit of specific hydrolases leads to the storage of undegraded substrates in lysosomes. Impaired enzyme activities can be assessed by MS/MS quantification of the reaction products obtained after incubation with specific substrates. In this study, a column‐switching HPLC‐MS/MS method for multiplex screening in dried blood spot of the lysosomal enzymes activities was developed. Mucopolysaccharidosis type I, Fabry, Gaucher, Krabbe, Niemann–Pick A/B and Pompe diseases were simultaneously assayed. Dried blood spots were incubated with substrates and internal standards; thereafter, supernatants were collected with minor manipulations. Samples were injected, trapped into an online perfusion column and, by a six‐port valve, switched online through the C18 analytical column to perform separation of metabolites followed by MS/MS analysis. A total of 1136 de‐identified newborn screening samples were analyzed to determine references for enzymes activity values. As positive controls, we analyzed dried blood spots from three patients with Pompe, one with Fabry, one with Krabbe disease and two with MPS I, and in all cases the enzyme activities were below the cutoff values measured for newborns, except for an MPS I patient after successful hematopoietic stem cell transplantation. Copyright © 2014 John Wiley & Sons, Ltd.