Age-Related Reference Intervals for Blood Amino Acids in Thai Pediatric Population Measured by Liquid Chromatography Tandem Mass Spectrometry

Abstract

Background Age, race, and analytic method influence levels of blood amino acids, of which reference intervals are required for the diagnosis and management of inherited metabolic disorders. Objectives To establish age-specific reference intervals for blood amino acids in Thai pediatric population measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). Methods A cross-sectional study of 277 healthy children from birth to 12 years was conducted. Anthropometric, clinical, and dietary information were recorded. Dried blood spots on a filtered paper were used for measurement by derivatized LC-MS/MS. Factors that might affect amino acids such as fasting time and dietary intake were analyzed using quantile regression analysis. Results Levels of thirteen blood amino acids were reported as median and interval from 2.5th–97.5th percentiles. Compared with those of Caucasian, most blood amino acid levels of Thai children were higher. Compared with a previous study using HPLC in Thai children, many amino acid levels are different. Glycine, alanine, leucine/isoleucine, and glutamic acid sharply decreased after birth. Citrulline, arginine, and methionine stayed low from birth throughout childhood, whereas phenylalanine was at middle level and slightly increased during preadolescence. Conclusion Reference intervals of age-specific blood amino acids using LC-MS/MS were established in the Thai pediatric population. They diverge from previous studies, substantiating the recommendation that, for the optimal clinical practice, age-specific reference intervals of amino acids should be designated for the particular population and analysis method.

Relation of Whole Blood Amino Acid and Acylcarnitine Metabolome to Age, Sex, BMI, Puberty, and Metabolic Markers in Children and Adolescents

“…Whereas numerous studies have been done in the field of newborn screening looking at dried blood levels of AAs and ACs, data regarding age-and sex-dependent variations of AA and AC concentration levels during child development in a healthy population are hard to come by. To our knowledge, only a few studies conducted to date have focused on AA and AC changes in serum, plasma, or dried whole blood during childhood [11][12][13]. These studies were mostly based on a smaller number of subjects (148-500 children) and did not consider associations with laboratory parameters relating to carbohydrate, fat, liver, kidney, and thyroid metabolism.…”

Profiles of Amino Acid in Indonesian Neonates

“…We also compared our results to reference interval from previous reports. (12,14,(23)(24)(25) Analyzing the pro le of amino acid in newborn showed the in uence of the nutritional status and protein nutrients taken by the mothers during gestation. (1) Indonesian pregnant women in different provincial area showed different preferences of food as there are many subethnicity in Indonesia.…”

“…The exclusion criteria were if the DBS samples quality were too small or compromised with mould. (12,15) Sample Collection…”

“…After DBS samples were taken for the screening, the rest of the DBS samples were stored at -20 o C until they were analyzed for amino acids. (12,14) Amino Acid Analysis Analysis was performed by LC-MS/MS system (Xevo TQD Tandem, Triple Quadrupole Mass Spectrometer; Waters Corporation, Massachusetts, USA). The protocol for amino acid measurement from DBS was in compliance with the manufacturer's guideline (Chromsystems, Munich/Germany and ClinSpot, Munich/Germany), as follows.…”

“…(13) However, there exists only limited reports with adequate sample size on amino acid concentration pro le in newborns obtained from DBS sample in South East Asian Countries and none for the Indonesian population. (12,14) Methods…”