In vitro probe acylcarnitine profiling assay using cultured fibroblasts and electrospray ionization tandem mass spectrometry predicts severity of patients with glutaric aciduria type 2.

Abstract

Glutaric aciduria type 2 (multiple acyl-CoA dehydrogenase deficiency, MAD) is a multiple defect of mitochondrial acyl-CoA dehydrogenases due to a deficiency of electron transfer flavoprotein (ETF) or ETF dehydrogenase. The clinical spectrum are relatively wide from the neonatal onset, severe form (MAD-S) to the late-onset, milder form (MAD-M). In the present study, we determined whether the in vitro probe acylcarnitine assay using cultured fibroblasts and electrospray ionization tandem mass spectrometry (MS/MS) can evaluate their clinical severity or not. Incubation of cells from MAD-S patients with palmitic acid showed large increase in palmitoylcarnitine (C16), whereas the downstream acylcarnitines; C14, C12, C10 or C8 as well as C2, were extremely low. In contrast, accumulation of C16 was smaller while the amount of downstream metabolites was higher in fibroblasts from MAD-M compared to MAD-S. The ratio of C16/C14, C16/C12, or C16/C10, in the culture medium was significantly higher in MAD-S compared with that in MAD-M. Loading octanoic acid or myristic acid led to a significant elevation in C8 or C12, respectively in MAD-S, while their effects were less pronounced in MAD-M. In conclusion, it is possible to distinguish MAD-S and MAD-M by in vitro probe acylcarnitine profiling assay with various fatty acids as substrates. This strategy may be applicable for other metabolic disorders.

• Authors: Mitsuru Endo, Yuki Hasegawa, Seiji Fukuda, Hironori Kobayashi, Yuka Yotsumoto, Yuichi Mushimoto, Hong Li, Jamiyan Purevsuren, Seiji Yamaguchi
• Journal: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences (J Chromatogr B Analyt Technol Biomed Life Sci) Vol. 878 Issue 20 Pg. 1673-6 (Jun 15 2010) ISSN: 1873-376X [Electronic] Netherlands
• PMID: 20392676 (Publication Type: Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: 2010 Elsevier B.V. All rights reserved.

Chemical References

• acylcarnitine
• Carnitine

Topics

• Carnitine (analogs & derivatives, chemistry, metabolism)
• Case-Control Studies
• Cells, Cultured
• Fibroblasts (chemistry, metabolism)
• Humans
• Molecular Structure
• Multiple Acyl Coenzyme A Dehydrogenase Deficiency (metabolism)
• Spectrometry, Mass, Electrospray Ionization (methods)