Abstract
BACKGROUND: Many muscular dystrophies currently remain untreatable. Recently, dietary ribitol has been suggested as a treatment for cytidine diphosphate (CDP)-L-ribitol pyrophosphorylase A (CRPPA, ISPD), fukutin (FKTN), and fukutin-related protein (FKRP) myopathy, by raising CDP-ribitol concentrations. Thus, to facilitate fast diagnosis, treatment development, and treatment monitoring, sensitive detection of CDP-ribitol is required.
METHODS: An LC-MS method was optimized for CDP-ribitol in human and mice cells and tissues.
RESULTS: CDP-ribitol, the product of CRPPA, was detected in all major human and mouse tissues. Moreover, CDP-ribitol concentrations were reduced in fibroblasts and skeletal muscle biopsies from patients with CRPPA myopathy, showing that CDP-ribitol could serve as a diagnostic marker to identify patients with CRPPA with severe Walker-Warburg syndrome and mild limb-girdle muscular dystrophy (LGMD) phenotypes. A screen for potentially therapeutic monosaccharides revealed that ribose, in addition to ribitol, restored CDP-ribitol concentrations and the associated O-glycosylation defect of alpha-dystroglycan. As the effect occurred in a mutation-dependent manner, we established a CDP-ribitol blood test to facilitate diagnosis and predict individualized treatment response. Ex vivo incubation of blood cells with ribose or ribitol restored CDP-ribitol concentrations in a patient with CRPPA LGMD.
CONCLUSIONS: Sensitive detection of CDP-ribitol with LC-MS allows fast diagnosis of patients with severe and mild CRPPA myopathy. Ribose offers a readily testable dietary therapy for CRPPA myopathy, with possible applicability for patients with FKRP and FKTN myopathy. Evaluation of CDP-ribitol in blood is a promising tool for the evaluation and monitoring of dietary therapies for CRPPA myopathy in a patient-specific manner. (C) 2019 American Association for Clinical Chemistry
Original language | English |
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Pages (from-to) | 1295-1306 |
Number of pages | 12 |
Journal | Clinical Chemistry |
Volume | 65 |
Issue number | 10 |
DOIs | |
Publication status | Published - Oct 2019 |
Keywords
- ALPHA-DYSTROGLYCAN
- POSTTRANSLATIONAL MODIFICATION
- DEFECTIVE GLYCOSYLATION
- GLYCOPROTEIN COMPLEX
- D-RIBOSE
- ISPD
- MUTATIONS
- FKRP
- METABOLISM
- THERAPY