Hu Lingwei, Hu Zhenzhen, Yang Jianbin, Zhang Yu, Shi Yezhen, Zhu Shasha, Yang Rulai, Huang Xinwen
Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Regional Medical Center for Children, Hangzhou 310052, China.
Zhejiang Biosan Biochemical Technologies Co., Ltd., Hangzhou 310012, China.
Zhejiang Da Xue Xue Bao Yi Xue Ban. 2020 Oct 25;49(5):565-573. doi: 10.3785/j.issn.1008-9292.2020.10.03.
To explore effects of different delivery and storage conditions on concentrations of amino acids and carnitines in neonatal dried blood spots (DBS), so as to provide evidence for improving accurate and reliable detection by tandem mass spectrometry.
A total of 1 254 616 newborn DBS samples in Newborn Screening Center of Zhejiang Province were delivered and stored at room temperature (group A, =338 467), delivered by cold-chain logistics system and stored at low temperature (group B, =480 021), or delivered by cold-chain logistics system and stored at low temperature and low humidity (group C, = 436 128), respectively. The concentrations of amino acids and carnitines in DBS were detected by tandem mass spectrometry. Data analysis was performed by SPSS 24.0 to explore the influence of temperature and humidity on the concentrations of amino acids and carnitines.
The concentrations of amino acids and carnitines in the three groups were skewed, and the differences in amino acid and carnitine concentrations among groups were statistically significant (all <0.01). The median concentration of tyrosine was lower in group A than those in group B and group C by 18%and 16%respectively, while there was no significant difference between the last two groups. The median concentrations of methionine were lower in group A and group B than that in group C by 15%and 11%, respectively. The median concentrations of arginine were lower in group A and group B than that in group C by 12%and 25%, respectively. The median concentration of free carnitine (C0) was higher in group A than that in group C by 12%, while there was no significant difference between group A and group B. The median concentrations of acetylcarnitine (C2), propionyl carnitine (C3), C3DC+C4OH, C5DC+C6OH and hexadecanoyl carnitine (C16) were lower in group A than those in group B and group C by 21%-64%. The concentrations of other amino acids and acylcarnitines differed little among three groups. The monthly median coefficients of variation of other amino acids and carnitines in group A were higher than those in group B and group C except for citrulline, C4DC+C5OH and isovalerylcarnitine (C5).
Cold-chain logistics system and storage in low temperature and low humidity can effectively reduce degradation of some amino acids and carnitines in DBS, improve the accuracy and reliability of detection, and thus ensures the quality of screening for neonatal metabolic diseases.
探讨不同运送及保存条件对新生儿干血斑（DBS）中氨基酸和肉碱浓度的影响，为提高串联质谱检测的准确性和可靠性提供依据。
浙江省新生儿疾病筛查中心共1 254 616份新生儿DBS样本，分别于室温下运送及保存（A组，n = 338 467）、采用冷链物流系统运送并低温保存（B组，n = 480 021）、采用冷链物流系统运送并低温低湿保存（C组，n = 436 128）。采用串联质谱法检测DBS中氨基酸和肉碱浓度。应用SPSS 24.0进行数据分析，探讨温度和湿度对氨基酸及肉碱浓度的影响。
三组样本中氨基酸和肉碱浓度呈偏态分布，组间氨基酸和肉碱浓度差异有统计学意义（均P<0.01）。A组酪氨酸中位数浓度分别低于B组和C组18%和16%，而后两组间差异无统计学意义。A组和B组蛋氨酸中位数浓度分别低于C组15%和11%。A组和B组精氨酸中位数浓度分别低于C组12%和25%。A组游离肉碱（C0）中位数浓度高于C组12%，而A组与B组间差异无统计学意义。A组乙酰肉碱（C2）、丙酰肉碱（C3）、C3DC+C4OH、C5DC+C6OH和十六酰肉碱（C16）中位数浓度分别低于B组和C组21% - 64%。其他氨基酸和酰基肉碱浓度三组间差异较小。除瓜氨酸、C4DC+C5OH和异戊酰肉碱（C5）外，A组其他氨基酸和肉碱的月度中位数变异系数高于B组和C组。
冷链物流系统及低温低湿保存可有效减少DBS中部分氨基酸和肉碱的降解，提高检测的准确性和可靠性，从而保证新生儿代谢病筛查质量。
