摘要目的 比较串联质谱两种前标本处理方法(衍生化法和非衍生化法)检测新生儿滤纸干血片上丙氨酸(Ala),精氨酸(Arg),瓜氨酸(Cit),甘氨酸(Gly),亮氨酸(Leu),甲硫氨酸(Met),鸟氨酸(Orn),苯丙氨酸(Phe),酪氨酸(Tyr),缬氨酸(Val) 10种氨基酸水平分布和差异,为实验室开展新生儿氨基酸代谢障碍疾病筛查提供方法学依据.方法 方法比较研究.选择2012年1至6月在上海市儿童医院新生儿筛查中心进行遗传代谢性疾病筛查滤纸干血片标本,共计4135份.采用衍生化法和非衍生化法及相应试剂盒:(1)同时检测100份新生儿滤纸干血片标本,以配对方式比较10种氨基酸水平之间差异；(2)分别各自检测2000份正常新生儿滤纸干血片标本,了解正常新生儿10种氨基酸水平分布；(3)同时检测经临床确诊的7种氨基酸代谢异常标本35份,验证两种方法临床判断的一致性.采用配对t检验.结果 正常新生儿的10种氨基酸水平经K-S单标本正态分布检验,Z值在1.997 ～6.229之间,呈偏态分布(P＜0.01)；除Leu和Tyr外,其余8种氨基酸非衍法比衍生法检测浓度低,两种方法检测均值差异,除Met高达47.8％外,其他9种氨基酸水平差异均＜10％,平均为7.8％；除Met、Phe和Tyr,两种方法测得的7种氨基酸水平差异无统计学意义(P＞0.05)；以0.5～99.5百分位数建立的10种氨基酸正常参考值范围,衍生法均比非衍法高,平均高25.3％,正常参考值范围有重叠；经临床验证,对于确诊患儿异常指标的检测,两种方法间无统计学意义(P＞0.05),两种方法均能检测出疾病患儿,检出率均为100％.结论 衍生法和非衍法检测多种氨基酸水平有差异,但对氨基酸代谢障碍疾病的异常指标的检测结果无差异,对疾病的临床判断无影响；两种方法均可用于新生儿氨基酸代谢障碍疾病的筛查.

abstractsObjective To provide methodological references for laboratories to carry out newborn screening for disorders of amino acid metabolism,we compared the difference and distribution of ten amino acids including alanine (Ala),arginine (Arg),citrulline (Cit),glycine (Gly),leucine (Leu),methionine (Met),ornithine (Orn),phenylalanine (Phe),tyrosine (Tyr),and valine (Val) from newborn dried blood spots specimen using derivatization or non-derivatization as sample preparation methods.Method It is a comparative research study.A total of 4135 newborn screening dried blood spot samples for inborn errors of metabolism were collected from January to June,2012.All specimens came from neonatal screening center of shanghai children's hospital.Samples were prepared by two different techniques,the corresponding kits and the procedures were used as follows:(1) Simultaneous detection of 100 dried blood spot specimens using two methods respectively to compare the paired difference of each amino acid.(2) 2000 cases of normal newborn specimens were detected respectively to obtain the normal distribution of ten neonatal amino acids.(3) 35 specimens from patients previously diagnosed positively as inborn errors of metabolism were simultaneously detected with 7 amino acids to verify the consistency of two techniques in clinical judgment.Results The amino acid levels of normal newborns analyzed by one-sample.kolmogorovSmirnov test (Z value ranged from 1.997 to 6.229) showed a skewed distribution (P ＜ 0.01).Except for Leu and Tyr,non-derivatization techniqueshowed a lower concentration than derivatization technique,and the CVs of nine amino acids were ＜ 10％ except for Met (the CV of Met was 47.8％),and the average CV is 7.8％.Except for Met,Phe and Tyr,the levels of other 7 amino acids measured by two techniques showed no significant difference (P ＞ 0.05).According to 0.5th to 99.5th percentiles,the normal reference range for derivatization method were greater than on-derivatization method,and the average value was 25.3％.After clinic judgment,the results of the abnormal indicators of children with true metabolism disorders showed no statistically significant between two methods (P ＞ 0.05),the detection rate was 100％.Conclusions There was a slight difference between derivatization and the non-derivatization techniques in detecting multiple amino acids.The results of the abnormal indicators of amino acid metabolism disordersshow no statically significant difference between the two methods,and no difference in clinical judgment.Both methods can be used in detecting amino acid metabolism disorders in newborn screening.