当前位置： SCI文献检索 > CLINICAL CHEMISTRY期刊下所有文献 > Liquid Chromatography-Tandem Mass Spectrometry Assay of Leukocyte Acid α-Glucosidase for Post-Newborn Screening Evaluation of Pompe Disease.

Liquid Chromatography-Tandem Mass Spectrometry Assay of Leukocyte Acid α-Glucosidase for Post-Newborn Screening Evaluation of Pompe Disease.

Abstract：

BACKGROUND:Pompe disease (PD) is the first lysosomal storage disorder to be added to the Recommended Uniform Screening Panel for newborn screening. This condition has a broad phenotypic spectrum, ranging from an infantile form (IOPD), with severe morbidity and mortality in infancy, to a late-onset form (LOPD) with variable onset and progressive weakness and respiratory failure. Because the prognosis and treatment options are different for IOPD and LOPD, it is important to accurately determine an individual's phenotype. To date, no enzyme assay of acid α-glucosidase (GAA) has been described that can differentiate IOPD vs LOPD using blood samples. METHODS:We incubated 10 μL leukocyte lysate and 25 μL GAA substrate and internal standard (IS) assay cocktail for 1 h. The reaction was purified by a liquid-liquid extraction. The extracts were evaporated and reconstituted in 200 μL methanol and analyzed by LC-MS/MS for GAA activity. RESULTS:A 700-fold higher analytical range was observed with the LC-MS/MS assay compared to the fluorometric method. When GAA-null and GAA-containing fibroblast lysates were mixed, GAA activity could be measured accurately even in the range of 0%-1% of normal. The leukocyte GAA activity in IOPD (n = 4) and LOPD (n = 19) was 0.44-1.75 nmol · h-1 · mg-1 and 2.0-6.5 nmol · h-1 · mg-1, respectively, with no overlap. The GAA activity of pseudodeficiency patients ranged from 3.0-28.1 nmol · h-1 · mg-1, showing substantial but incomplete separation from the LOPD group. CONCLUSIONS:This assay allows determination of low residual GAA activity in leukocytes. IOPD, LOPD, and pseudodeficiency patients can be partially differentiated by measuring GAA using blood samples.

journal_name

Clin Chem

journal_title

Clinical chemistry

authors

Lin N,Huang J,Violante S,Orsini JJ,Caggana M,Hughes EE,Stevens C,DiAntonio L,Chieh Liao H,Hong X,Ghomashchi F,Babu Kumar A,Zhou H,Kornreich R,Wasserstein M,Gelb MH,Yu C

doi

10.1373/clinchem.2016.259036

subject

Has Abstract

pub_date

2017-04-01 00:00:00

pages

842-851

issue

eissn

0009-9147

issn

1530-8561

pii

clinchem.2016.259036

journal_volume

pub_type

杂志文章

在线工具

Liquid Chromatography-Tandem Mass Spectrometry Assay of Leukocyte Acid α-Glucosidase for Post-Newborn Screening Evaluation of Pompe Disease.