Analysis of glucocerebrosidase activity in dry blood spots using tandem mass spectrometry

作者：Legini Elisa; Orsini Joseph J; Hung Christina; Martin Monica; Showers Amanda; Scarpa Maurizio; Zhang X Kate; Keutzer Joan; Muehl Adolf; Bodamer Olaf A^*

来源：Clinica Chimica Acta, 2011, 412(3-4): 343-346.

DOI：10.1016/j.cca.2010.11.006

• Dry blood spot
• Enzyme
• Filter card
• Lysosomal
• Mass spectrometry

Background: Gaucher disease (GD) is due to deficiency of acid-beta-glucosidase (ABG) and comprises a clinical spectrum with variable age of onset and severity. We evaluated a tandem mass spectrometry (MS/MS) method to measure ABG activity for high through-put screening.
Methods: ABG activity was measured in 3.2 mm punches from dry blood spots (DBS). Each punch was incubated for 21 h with the substrate D-Glucosyl-beta 1-1'-N-dodecanoyl-D-erythro-sphingosine [C12-glucocerebroside (C36H69NO8)] and internal standard N-myristoyl-D-erythro-sphingosine [C14-ceramide (C32H63NO3)]. The product and internal standard were quantified using MS/MS.
Results: ABG activities in anonymized newborn screening samples from NY State were (mean) 22.0 mu mol/h/L +/- (SD) 13.8 mu mol/h/L (n = 2088, median 19.9 mu mol/h/L, 95%CI 22.59-21.41 mu mol/h/L). The enzymatic activity in DBS from 10 treatment naive adult Gaudier patients was less than 4.2 mu mol/h/L. ABG activity was stable for 3 months at room temperature a 20% activity reduction was observed. Inter- and intra-run imprecisions were 8% and 13.7%, respectively. The limit of detection was 0.75 mu mol/h/L and limit of quantification was 1.25 mu mol/h/L.
Conclusions: The measurement of ABG activities in DBS using MS/MS is suitable for high-throughput analysis of at-risk individuals and potentially for newborn screening for GD.

• 出版日期2011-1-30