Monitoring of tacrolimus in 448 samples from renal transplant recipients by ELISA

OBJECTIVE To monitor the trough concentration of tacrolimus in whole blood in Chinese renal transplant recipients and establish an optimal therapeutic window of tacrolimus, which will provide information for rational adiministration in clinic. METHODS The whole blood concentrations of tacrolimus were measured by ELBA. The levels of tacrolimus in 448 samples from 75 renal transplant recipients were compared and studied. RESULTS The whole blood concentration of tacrolimus was gradually diminished with time after operation. The optimal therapeutic windows of tacrolimus for renal transplant recipients were 8 ~ 15ug.L~1 within 1 month after operation, 6 ~ 12ug.L-1 in the 2nd ~ 3rd months, 5 ~ 10 ug. L-1 in the 4th ~ 6th months and 3 ~ 8 ug. 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.