Validation of an LC-MS/MS assay for detecting relevant disaccharides from keratan sulfate as a biomarker for Morquio A syndrome

Bioanalysis. 2011 Aug;3(16):1855-66. doi: 10.4155/bio.11.172.

Abstract

Background: Mucopolysaccharidosis IVA (MPS IVA, Morquio A syndrome) is an inherited lysosomal storage disease caused by deficiency of N-acetylgalactosamine-6-sulfatase (GALNS), an enzyme required for stepwise degradation of keratan sulfate (KS). We have developed a selective, sensitive, accurate and precise LC-MS/MS assay for the KS-derived disaccharides Galβ1-4GlcNAc(6S) and Gal(6S)β1-4GlcNAc(6S) in human urine and plasma using keratanase II digestion.

Results: Mean accuracy was 96-106% in urine and 97-108% in plasma. Precision was high, with relative standard deviations of 1-2% (intra-day) and 2-5% (inter-day) in urine and 1-2% (intra-day) and 4-7% (inter-day) in plasma. The lower limit of quantitation was 0.026 µg/ml (plasma) and 0.104 µg/ml (urine), with a quantitation range of 0.026-5 µg/ml (plasma) and 0.104-20 µg/ml (urine).

Conclusion: Clinical sample analysis in 168 MPS IVA patients and 225 healthy controls demonstrates the clinical utility of this method.

Trial registration: ClinicalTrials.gov NCT00787995.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Biomarkers / blood
  • Biomarkers / urine
  • Child
  • Child, Preschool
  • Chromatography, Liquid / methods*
  • Disaccharides / blood*
  • Disaccharides / urine*
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Keratan Sulfate / blood*
  • Keratan Sulfate / urine*
  • Male
  • Mass Spectrometry / methods
  • Middle Aged
  • Mucopolysaccharidosis IV / blood
  • Mucopolysaccharidosis IV / diagnosis*
  • Mucopolysaccharidosis IV / urine

Substances

  • Biomarkers
  • Disaccharides
  • Keratan Sulfate

Associated data

  • ClinicalTrials.gov/NCT00787995