A Multiplex Assay for the Diagnosis of Mucopolysaccharidoses and Mucolipidoses.

Autor: Eveline J Langereis, Tom Wagemans, Wim Kulik, Dirk J Lefeber, Henk van Lenthe, Esmee Oussoren, Ans T van der Ploeg, George J Ruijter, Ron A Wevers, Frits A Wijburg, Naomi van Vlies
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: PLoS ONE, Vol 10, Iss 9, p e0138622 (2015)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0138622
Popis: 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).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.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.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.
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