Detection of serum mitochondria aspartate aminotransferase by immunosuppression method and the relationship between the enzyme activity and liver injury

Objective To establish a immunosuppression assay for detecting serum mitochondria aspartate aminotransferase (m-AST) isoenzyme and to understand the relationship among the m-AST activities and the severity of liver injury. Methods Activities finelinearity of m-AST and total AST in sera from 82 healthy individuals, 33 chronic hepatitis (CH) and 19 fulminant hepatitis (FH) patients, and then the m-AST/AST ratios was calculated. Results A fine linearity of m-AST activity by this assay was found in range of 200U/L. Coefficient of variations within-run and between-run were less than 3.71% and 3.91% respectively. The recovery rates were from 96.3% to 104.6% and mean of the rates was 100.5%. In serum samples from the healthy individuals, m-AST activity values were 1.1±0.4U/L and m-AST/AST ratios were and 5.7±1.8%. m-AST activity values and m-AST/AST ratios were 82.6±30.9U/L and 26.1±22.5% for 33 CH patients and 152.9±29.5 U/L and 30.5±25.2% for FH patients, respectively. A high statistically significances could be found in the comparison of the m-AST activity values and m-AST/AST ratios beween the patients and normal controls (P0.01). The serum m-AST activity values and m-AST/AST ratios between CH and FH patients were also significantly different (P0.01). Conclusions The immunosuppression assay used in this study is a simple, rapid and well-repeated method for detecting serum m-AST activity. m-AST activities in sera is able to reflect severity of liver injury.