Applying percentile method combined with ROC curve to determine the reference values for 11 amino acids in newborns measured by non-derivatized tandem mass spectrometry / 中华检验医学杂志

ABSTRACT

Objective To determine the reference values of 11 amino acids measured by non-derivatized tandem mass spectrometry ( MS/MS).Methods 22 430 healthy newborns and 14 children with metabolic dysfunction in Nanjing were enrolled in this study.The levels of the 11 amino acids, including Ala, Arg, Cit, Gly, Leu +Ile, Met, Orn, Phe, Pro, Tyr and Val, were measured by non-derivatized tandem mass spectrometry using dry blood spots.After pre-setting up different cutoff values according to the amino acid levels of the newborns, reference value ranges of the 11 amino acids were determined by using the method of percentile combined with ROC curves.Results According to the results of frequency distribution histogram, the levels of the 11 amino acids of newborns belong to approximate normal distribution.By analysis of ROC curves, the cut-off values for amino acids were 0.2%-99.8%.Conclusion It established reference values of 11 amino acids in newborn and provided basis for the other screening center to make the cut-off value.