Abstract:

Objective To investigate the status of alanine aminotransferase（ALT）trueness verification in Shanghai and the application of stabilizer betaine in trueness control samples,so as to optimize trueness verification. Methods A total of 4 trueness control samples（ALT-A,ALT-B,ALT-C and ALT-D）undergoing centrifugation and filtration processing were delivered to clinical laboratories under cold chain. ALT-B and ALT-D were added stabilizer betaine,and the trueness control samples were determined for 3 d. The trueness control samples were assigned using the International Federation of Clinical Chemistry and Laboratory Medicine（IFCC）primary reference method,obtaining target values. The bias of each trueness control sample's mean and target value in each laboratory was calculated,and the allowable bias judgment standard was ≤6%. Stability experiment for 3 d at -20℃of trueness control samples was performed by synchronizing method,and the stabilities of 4 trueness control samples in all laboratories were analyzed. Results At -20 ℃ for 3 d,ALT-B and ALT-D had good stabilities （the activities at the 3 rd day were 99.1% and 100.0% of initial value）. ALT-A and ALT-C were unstable（the activities at the 3 rd day were 96.7% and 94.9% of initial value）,which were the same as those for trueness control samples in all laboratories.Among 74 laboratories,there were 23.0%（17 cases） of ALT-A and 33.8%（25 cases） of ALT-C in the range of allowable bias,while there were 66.2%（49 cases） of ALT-B and ALT-D in the range of allowable bias. There were 65.8% （27 cases）of ALT-B and 63.4%（26 cases）of ALT-D in the range of allowable bias in 41 Level 3 hospitals,and there were 66.7%（22 cases）of ALT-B and 69.7%（23 cases）of ALT-D in the range of allowable bias in 33 Level 2 hospitals. There were 59.5%（44 cases）of ALT-B and ALT-D in the range of allowable bias,of which 61.0%（25 cases） in Level 3 hospitals and 57.6%（19 cases） in Level 2 hospitals. Conclusions There is no difference for bias between Level 3 and Level 2 hospitals. ALT trueness control samples with no stabilizer can not meet the needs of trueness verification,and ALT trueness control samples adding stabilizer betaine can satisfy the needs of trueness verification.

Key words: Alanine aminotransferase, Trueness verification, Trueness control samples, Traceability