Abstract:

Objective To investigate the comparability and clinical acceptability of the screening results of neonatal genetic metabolic diseases with different tandem mass spectrometry determination systems. Methods The QSight 210MD tandem mass spectrometer（referred to as QSight 210MD） and the UPLC I-Class Xevo TQD tandem mass spectrometer（referred to as Xevo TQD） were used to determine the levels of amino acids,free carnitine and acyl carnitine in dried blood spot samples of 40 newborns. According to the EP9-A2 document of the Clinical and Laboratory Standards Institute（CLSI）,the intra-assay and inter-assay precisions,correlation and clinical acceptabilities of QSight 210MD and Xevo TQD were evaluated. Results The intra-assay and inter-assay precisions of each comparison project of QSight 210MD and Xevo TQD were both <7%,which met the clinical requirements. Between QSight 210MD and Xevo TQD,except for glutaryl carnitine（C5DC）,caproyl carnitine（C6） and octanoyl carnitine（C8）,r were <0.975,and r were >0.975 for the other items. The relative systematic error（SE%） of all the items was <1/2 allowable total error（TEa） of the national inter-room quality assessment,which was clinically acceptable. Conclusions Except for C5DC,C6 and C8,between QSight 210MD and Xevo TQD,the results of the other neonatal genetic metabolic disease screening items have good correlations,which can meet the clinical requirements. For the items that are not comparable,it is necessary to establish different reference intervals for different determination systems.

Key words: Tandem mass spectrometry, Result comparison, Bias evaluation