Abstract:

Objective By comparing the determination results of mitochondrial aspartate aminotransferase （m-AST） reagents of 7 brands，the influencing factors of the harmonization of serum samples determined by different brands of m-AST reagents have been discussed in order to provide a reference for the harmonization of m-AST determination results in Shanghai. Methods Seven m-AST determination systems and 7 aspartate aminotransferase（AST）determination systems were composed of m-AST and AST determination reagents of 7 brands and Hitachi 3500 automatic analyzer. Seven m-AST and AST determination systems were used to determine 30 serum samples. The 7 m-AST systems were paired in pairs to form 21 comparison combinations，and the correlation coefficients of 21 groups were calculated. Passing-Bablok regression analysis was used to analyze the slope and intercept of the 21 groups，and Bland-Altman analysis was used to analyze the relative average deviation of the 21 groups. The coefficient of variation（CV）and mean CV of m-AST and AST results of the same serum samples determined by 7 m-AST and AST determination systems were calculated，respectively，as well as the ratio of the determination results of 7 m-AST determination systems to the corresponding AST determination systems. Results Among the 21 m-AST system comparison combinations，except for one group，the harmonization of the results in the remaining 20 groups was poor. The average CV of the same clinical sample determined by 7 m-AST determination systems was 39.53%，and the average CV of the same clinical sample determined by 7 AST determination systems was 6.17%. The ratio of m-AST to AST was different from that of each determination system，except for one determination system and the corresponding AST determination system，and the ratio of the determination results of the other systems at each concentration level fluctuated significantly，but the fluctuation trend was consistent. Conclusions There are significant differences in the results of m-AST，which lacks comparability. The reason for the lack of comparability of m-AST results is mainly the difference in the inhibition rate of cytoplasmic aspartate aminotransferase （c-AST） among various reagents.

Key words: Mitochondrial aspartate aminotransferase, Aspartate aminotransferase, Harmonization, Comparability