Evaluation of a panel of very long-chain lysophosphatidylcholines and acylcarnitines for screening of X-linked adrenoleukodystrophy in China.

BACKGROUND: Elevated blood C24:0- and C26:0-carnitines and lysophosphatidylcholines (LPCs) were reported as diagnostic biomarkers for X-linked adrenoleukodystrophy (X-ALD). Our aim was to establish the reference intervals of very long-chain (VLC) acylcarnitines (C20-C26) and LPCs in Chinese population, and evaluate valuable biomarkers and develop panel for screening X-ALD in China. METHODS: The method of FIA-MS/MS-based quantification of VLC acylcarnitines and LPCs was validated in order to determine their concentrations in dried blood spots from 7 X-ALD boys, 396 age-matched healthy controls, and 3078 putative normal newborns. Screening performance of these metabolites for X-ALD was clinically evaluated. RESULTS: The reference intervals of VLC acylcarnitines, LPCs and their ratios were established in Chinese population, and for some metabolites like C26 and C26:0-LPC, the reference intervals were found to be significantly different between children and newborns. C24 and C26, C26:0-LPC, C24/C22 and C26/C22 ratios were found to have better performance than other analytes to identify X-ALD boys from normal children. CONCLUSION: C26:0-LPC, C24 and C26 are three most valuable biomarkers for screening of X-ALD in children group. The information of age-related variations in concentration of some biomarkers is helpful for accurate screening of X-ALD.