MSACL 2017 US Abstract

Worldwide Newborn Screening for Lysosomal Storage Diseases by Tandem Mass Spectrometry

Michael Gelb (Presenter)
Univ. of Washington

Bio: I am the Professor and Boris and Barbara L. Weinstein Endowed Chair in Chemistry at the Univ of Washington, where I have run my own research lab since 1985. Of recent interest to the MSACL conference is our lab developed methods for MS/MS newborn screening of lysosomal storage diseases that are now in recent routine use worldwide. Other major discoveries of the Gelb lab are ICAT reagents for quantitative proteomics, protein farnesylation and geranylgeranylation, clinical candidates for parasitic diseases, and interfacial enzymology of phospholipases A2.

Authorship: Michael H. Gelb
Univ. of Washington

Short Abstract Our lab developed tandem mass spectrometry for multiplex analysis of several enzymes in dried blood spots for newborn screening of lysosomal storage diseases. Recently several US states have expanded their newborn screening programs to include these methods. They are also carried out in Taiwan and Australia. More recently we have put all the assays together into a single multiplex LC-MS/MS assay of 13 lysosomal storage diseases including enzyme assays and biomarkers. Also included are biomarkers for additional diseases for which newborn screening is being considered (bile acid disorders for example). The work shows how mass spectrometry can uniquely address the challenges of newborn screening of several rare and treatable metabolic diseases using a single punch of a dried blood spot and in a high throughput manner appropriate for use in newborn screening laboratories worldwide.

Long Abstract

Introduction: Newborn screening for several new diseases (mainly lysosomal storage diseases) is of interest because of the availability of treatment options that give the best outcome if carried out early in life (before the onset of irreversible symptoms). Mass spectrometry has emerged as the method of choice for expansion of newborn screening programs to include the new diseases.

Methods: A single punch of a dried blood spot on a newborn screening card is used as the source of enzymes, and a second punch is used for biomarker extraction. After a simple pre-MS/MS workup, samples are analyzed by UPLC-MS/MS (electrospray ionization with multiple reaction monitoring, MRM) in a single analysis of more than 25 metabolites (enzyme products and biomarkers) in < 2 min per sample. The developed assays are being employed in large scale pilot studies in the WA state newborn screening laboratory to test the robustness of the methods and to determine the disease frequencies.

Results: Using a single UPLC-MS/MS run (< 2 min per sample) it is possible to detect the products of 13 different lysosomal enzymes as well as to quantify several biomarkers that accumulate in the disease state (bile acid precursors, sulfatides, lysophospholipids, lysosphingolipids). The method is sufficiently rapid, robust, economical and easy to execute for newborn screening laboratories. The analytical ranges of the MS/MS assays are more than an order-of-magnitude larger than those for the corresponding fluorimetric assays, and fluorimetric assays for the biomarkers and some of the enzyme activities is not possible. As a result, the number of false positives obtained with MS/MS is 5-10 fold lower than those obtained with fluorimetric methods.

Conclusions: Using a single UPLC-MS/MS assay in < 2 min per sample, it is possible to quantify the activity of 13 lysosomal enzymes and more than 10 biomarkers for lysosomal storage diseases and bile acid disorders. Newborn screening for these conditions is feasible and is advancing rapidly worldwide as a result of this new technology.

References & Acknowledgements:

Most of the work that will be presented is unpublished.

Financial Disclosure

IP Royalty: yes

IP Desc:PerkinElmer LSD newborn screening reagents and kits

Planning to mention or discuss specific products or technology of the company(ies) listed above:

yes