Reference intervals for ALT, AST, GGT and LDH among the Han Chinese in Beijing area

Objective To establish the reference intervals for ALT,AST,GGT and LDH among the Han nationality in Beijing.Methods The document C28-P3 issued by CLSI was a guideline about how to define,establish,and verify reference intervals in the clinical laboratory.IFCC had established multicenter enzymes reference intervals based on the guideline.Exclusion criteria were designed for screening candidate reference individual according to the document C28-P3 and the multicenter study's experience.Blood specimens were collected from 315 healthy individuals aged 20 to 60 years old,including 132 males and 183 females.Reference materials were used to ensure the accuracy of the test results of the four liver enzymes.The methods which used to test the four liver enzymes could be traced to the IFCC enzymes reference measure procedure,the reagent of ALT and AST included pyridoxal phosphate.Results There was statistically difference between males and females of the reference ranges for ALT, AST and GGT.Therefore,gender-specific reference intervals were established as ALT:8.2 -50.8 U/L (F),12.7 -71.8 U/L (M) ; AST:15.0 -36.7 U/L ( F),16.6 -51.1 U/L (M) ;GGT:9.0 -37.3 U/L (F),12.0 -50.9 U/L (M).For LDH,the reference interval was 127 -224 U/L,as no significant gender difference was found.Conclusions The reference intervals for the four liver enzymes based on the population of the Han nationality in Beijing are established.The upper reference limit for ALT in Beijing Han population is higher than that from other similar studies. Key words: Alanine transaminase;  Aspartate aminotransferases ;  Gamma-Glutamyltransferase; L-lactate dehydrogenase;  Reference value