Novel heparan sulfate assay by using automated high-throughput mass spectrometry: Application to monitoring and screening for mucopolysaccharidoses.

Abstract

Mucopolysaccharidoses (MPS) are caused by deficiency of one of a group of specific lysosomal enzymes, resulting in excessive accumulation of glycosaminoglycans (GAGs). We previously developed GAG assay methods using liquid chromatography tandem mass spectrometry (LC-MS/MS); however, it takes 4-5 min per sample for analysis. For the large numbers of samples in a screening program, a more rapid process is desirable. The automated high-throughput mass spectrometry (HT-MS/MS) system (RapidFire) integrates a solid phase extraction robot to concentrate and desalt samples prior to direction into the MS/MS without chromatographic separation; thereby allowing each sample to be processed within 10s (enabling screening of more than one million samples per year). The aim of this study was to develop a higher throughput system to assay heparan sulfate (HS) using HT-MS/MS, and to compare its reproducibility, sensitivity and specificity with conventional LC-MS/MS. HS levels were measured in the blood (plasma and serum) from control subjects and patients with MPS II, III, or IV and in dried blood spots (DBS) from newborn controls and patients with MPS I, II, or III. Results obtained from HT-MS/MS showed 1) that there was a strong correlation of levels of disaccharides derived from HS in the blood, between those calculated using conventional LC-MS/MS and HT-MS/MS, 2) that levels of HS in the blood were significantly elevated in patients with MPS II and III, but not in MPS IVA, 3) that the level of HS in patients with a severe form of MPS II was higher than that in an attenuated form, 4) that reduction of blood HS level was observed in MPS II patients treated with enzyme replacement therapy or hematopoietic stem cell transplantation, and 5) that levels of HS in newborn DBS were elevated in patients with MPS I, II or III, compared to those of control newborns. In conclusion, HT-MS/MS provides much higher throughput than LC-MS/MS-based methods with similar sensitivity and specificity in an HS assay, indicating that HT-MS/MS may be feasible for diagnosis, monitoring, and newborn screening of MPS.

• Authors: Tsutomu Shimada, Joan Kelly, William A LaMarr, Naomi van Vlies, Eriko Yasuda, Robert W Mason, William Mackenzie, Francyne Kubaski, Roberto Giugliani, Yasutsugu Chinen, Seiji Yamaguchi, Yasuyuki Suzuki, Kenji E Orii, Toshiyuki Fukao, Tadao Orii, Shunji Tomatsu
• Journal: Molecular genetics and metabolism (Mol Genet Metab) 2014 Sep-Oct Vol. 113 Issue 1-2 Pg. 92-9 ISSN: 1096-7206 [Electronic] United States
• PMID: 25092413 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Glycosaminoglycans
• Heparitin Sulfate

Topics

• Adolescent
• Adult
• Case-Control Studies
• Child
• Child, Preschool
• Chromatography, Liquid
• Dried Blood Spot Testing (methods, standards)
• Glycosaminoglycans (blood)
• Heparitin Sulfate (blood)
• High-Throughput Screening Assays
• Humans
• Infant
• Infant, Newborn
• Mass Spectrometry
• Mucopolysaccharidoses (blood, diagnosis)
• Neonatal Screening (methods, standards)
• Reproducibility of Results
• Tandem Mass Spectrometry
• Young Adult