RESUMEN
OBJECTIVES: Reference intervals are indispensable for the accurate clinical interpretation of clinical laboratory tests. The reference intervals of amino acids in dried blood spots (DBS) from nonnewborn children are limited. In this study, we aim to establish the pediatric reference intervals for amino acids in DBS from healthy Chinese children aged from 1 to 6 years and to investigate the effect of sex and age. DESIGN AND METHODS: In 301 healthy subjects aged from 1 to 6 years old, eighteen DBS amino acids were determined using ultra-performance chromatography-tandem mass spectrometry method. Amino acid concentrations were examined in relation to sex and age. Reference intervals were established according to the CLSI C28-A3 guidelines. RESULTS: Reference intervals of 18 amino acids bounded by the 2.5 and 97.5 percentiles were calculated in DBS specimen. No significant influence of age was observed for all the target amino acid concentrations in 1- to 6-year-olds. Sex differences were found in leucine and aspartic acid. CONCLUSIONS: The RIs established in the present study added value for diagnosing and managing the amino acid-related diseases in the pediatric population.