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A Multiplex Assay for the Diagnosis of Mucopolysaccharidoses and Mucolipidoses.

A Multiplex Assay for the Diagnosis of Mucopolysaccharidoses and Mucolipidoses.

Authors :
Langereis EJ
Wagemans T
Kulik W
Lefeber DJ
van Lenthe H
Oussoren E
van der Ploeg AT
Ruijter GJ
Wevers RA
Wijburg FA
van Vlies N
Source :
PloS one [PLoS One] 2015 Sep 25; Vol. 10 (9), pp. e0138622. Date of Electronic Publication: 2015 Sep 25 (Print Publication: 2015).
Publication Year :
2015

Abstract

Introduction: Diagnosis of the mucopolysaccharidoses (MPSs) generally relies on an initial analysis of total glycosaminoglycan (GAG) excretion in urine. Often the dimethylmethylene blue dye-binding (DMB) assay is used, although false-negative results have been reported. We report a multiplexed diagnostic test with a high sensitivity for all MPSs and with the potential to identify patients with I-cell disease (ML II) and mucolipidosis III (ML III).<br />Methods: Urine samples of 100 treatment naive MPS patients were collected and analyzed by the conventional DMB assay and a multiplex assay based on enzymatic digestion of heparan sulfate (HS), dermatan sulfate (DS) and keratan sulfate (KS) followed by quantification by LC-MS/MS. Specificity was calculated by analyzing urine samples from a cohort of 39 patients suspected for an inborn error of metabolism, including MPSs.<br />Results: The MPS cohort consisted of 18 MPS I, 16 MPS II, 34 MPS III, 10 MPS IVA, 3 MPS IVB, 17 MPS VI and 2 MPS VII patients. All 100 patients were identified by the LC-MS/MS assay with typical patterns of elevation of HS, DS and KS, respectively (sensitivity 100%). DMB analysis of the urine was found to be in the normal range in 10 of the 100 patients (sensitivity 90%). Three out of the 39 patients were identified as false-positive, resulting in a specificity of the LS-MS/MS assay of 92%. For the DMB this was 97%. All three patients with MLII/MLIII had elevated GAGs in the LC-MS/MS assay while the DMB test was normal in 2 of them.<br />Conclusion: The multiplex LC-MS/MS assay provides a robust and very sensitive assay for the diagnosis of the complete spectrum of MPSs and has the potential to identify MPS related disorders such as MLII/MLIII. Its performance is superior to that of the conventional DMB assay.

Details

Language :
English
ISSN :
1932-6203
Volume :
10
Issue :
9
Database :
MEDLINE
Journal :
PloS one
Publication Type :
Academic Journal
Accession number :
26406883
Full Text :
https://doi.org/10.1371/journal.pone.0138622