Monitoring whole blood concentration of tacrolimus in 1190 samples from liver transplant recipients by ELISA

AIM: To monitor the concentration of tacrolimus in whole blood in liver transplant recipients and establish an optimal therapeutic window of tacrolimus, in order to provide information for rational usage in clinic. METHODS: The whole blood concentrations of tacrolimus were measured by ELISA. The levels of tacrolimus in 1190 samples from 138 liver transplant recipients were compared and studied. RESULTS: The whole blood concentration of tacrolimus is gradually decreased with time after operation. The optimal therapeutic window of tacrolimus for liver transplant recipients was 8-15 μg·L -1 within 1 month after operation, 6-12 μg·L -1 from the 2nd to 3rd months, 5-10 μg·L -1 from the 4th to 6th months and 3-8 μg·L -1 after 6 months, respectively. CONCLUSION: It is necessary to routinely monitor blood concentration of tacrolimus. The satisfying therapeutic effects will be obtained if dosage regimens will be individualized according to optimal therapeutic window.