Primary investigation of serum alanine aminotransferase and aspartate aminotransferase reference intervals in healthy population

Objective To investigate the reference intervals of serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) measured by the reagents with pyridoxal 5′-phosphate(PLP),and compare with the reference intervals detected by the reagents without PLP.Methods A total of 3 249 healthy subjects were enrolled in this study.According to the recommended method by International Federation of Clinical Chemistry and Laboratory Medicine(IFCC),their ALT and AST levels were determined,and the detection system was calibrated by the cfas(Roche) reagents with and without PLP,respectively.Results There was significant difference between the concentrations of ALT and AST detected by the reagents with and without PLP(P0.000 1).The concentrations of ALT and AST were different between healthy males and females(P0.000 1).As the 95th upper limit of reference interval detected by the reagents with PLP,ALT was 55 IU/L for males,and 36 IU/L for females,and AST was 42 IU/L for males,and 33 IU/L for females,respectively.As the 95th upper limit of reference interval detected by the reagents without PLP,APT was 50 IU/L for males,and 32 IU/L for females,and AST was 35 IU/L for males,and 28 IU/L for females,respectively.The levels of ALT and AST both increased with age.Conclusions The activities of ALT and AST detected by the reagents with PLP increase in healthy subjects.PLP can effectively activate the activities of ALT and AST.Detecting the concentrations of ALT and AST by the reagents with PLP can indicate the true activities of ALT and AST.The detecting method of ALT and AST by reagents with PLP is recommended as the routine method.