Determination of the reference values of amino acids and acylcarnitines level in the newborn dry blood spots in Ukraine

Abstract

Aim. Implementation of neonatal screening of the group of severe inherited disorders of amino acids, fatty and organic acids metabolism in Ukraine involves determination of the biological variation of amino acids and acylcarnitines level in the blood that depends on the gender, geographical origin of the samples and the gestation term of newborn. Methods. The main method of rapid and reliable diagnosis of this group of inherited disorders is determination of amino acids and acylcarnitines level by liquid chromatography tandem mass spectrometry. Results. Reference intervals of amino acids and acylcarnitines concentration in dry blood samples of newborns from different regions of Ukraine haven’t differed. However, it was found necessity to use separate reference intervals of some amino acids and acylcarnitines (citrulline, arginine, methionine, leucine, tyrosine, alanine, histidine, C0, C3, C3DC, C4, C5, C6, C8, C8:1, C10:2, C12, C14:1, C16, C18OH, C18:1OH) for premature and full-term newborns. Also, it was revealed that for male and female newborns it is necessary to use different reference intervals of citrulline, leucine, C8:1, arginine, methionine, C5, C8. Conclusions. In this study it was found that variation of amino acids and acylcarnitines concentration in dry blood spots depends on the newborns gestation term and sex. We have proposed a two-stage procedure of biomarkers interpretation for which the values variation in different neonatal groups was detected. Keywords: amino acids and acylcarnitines reference intervals, inherited disorders of amino acids, fatty and organic acids metabolism, newborn screening.