Erythrocyte galactose 1-phosphate quantified by isotope-dilution gas chromatography-mass spectrometry
| Autor: | Jie, Chen, Claire, Yager, Robert, Reynolds, Michael, Palmieri, Stanton, Segal |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Adult
Galactosemias Male Quality Control Chromatography Gas Erythrocytes Galactosephosphates Infant Newborn Infant Reproducibility of Results Middle Aged Sensitivity and Specificity Gas Chromatography-Mass Spectrometry Neonatal Screening Reference Values Child Preschool Humans Female Sugar Phosphates Child |
| Zdroj: | Clinical chemistry. 48(4) |
| ISSN: | 0009-9147 |
| Popis: | Measurements of alpha-D-galactose 1-phosphate (Gal-1-P) in erythrocytes are used to monitor the adequacy of dietary therapy in the treatment of galactosemia. We have devised a gas chromatography-mass spectrometry (GC/MS) isotope-dilution method for quantification of Gal-1-P.We prepared trimethylsilyl (TMS) derivatives and used alpha-D-[2-(13)C]Gal-1-P as the internal standard for GC/MS. Results obtained with this method were compared with those determined by the established enzymatic method for samples from 23 healthy individuals (11 children and 12 adults), 9 suspected patients with galactosemia, 12 galactosemic patients on diet therapy, and 2 newly diagnosed toxic neonates.The method was linear up to 2.5 mmol/L with a lower limit of detection of 2.1 nmol (0.55 mg/L). Intra- and interassay imprecision (CVs) was 2.2-8.8%. In the 23 healthy individuals, values ranged from nondetectable to 9.2 micromol/L (2.4 mg/L of packed erythrocytes). Galactosemic patients on diet therapy had values of 10.9-45 mg/L of packed erythrocytes, whereas the newly identified patients had values of 166 and 373 mg/L.The GC/MS method is precise and useful over the wide range of concentrations needed to assess the galactose burden in patients with galactosemia. |
| Databáze: | OpenAIRE |
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