Effect Of Different Serum Levels Of Tacrolimus To Transplant-Renal Doppler Resistance Indices

Objective:The calcineurin inhibitors (CNI), mainly including cyclosporine and tacrolimus, have been the first-line immunosuppression in the organ transplantation field, but they can also induce the intrarenal vasoconstriction. Some studies show that serum peak levels of cyclosporine can induce acute rise of the renal resistance indices. In this study, we researched whether different serum levels of tacrolimus can affect the renal Doppler resistance indices (RIs).Methods:With an ideal recovery of the renal function,32 kidney transplant recipients were enrolled for the study. On about 12th day after the surgery, we performed the Doppler examination on the transplant kidney before (trough serum level,C0) and 2 hours later (peak serum level,C2) after the intake of tacrolimus, respectively. The RIs on the renal artery, segmental artery, interlobar artery and arcuate artery were measured. At the same time heart rate, arterial pressure and serum tacrolimus concentration were also measured. All the data were compared before and 2 hours after the intake of tacrolimus. Results:All the average RIs of the renal artery, segmental artery, interlobar artery and arcuate artery had a significant rise at 2 hours after the intake of tacrolimus. After a correction renal RIs with the heart rate, the difference between the average renal artery, segmental artery, and interlobar artery RIs before and 2 hours after the intake of tacrolimus disappeared, while the arcuate artery RIs remained higher.Conclusion:Peak levels of tacrolimus has no effect to the larger intrarenal resistance indices in stable renal transplant patients, but can lead an acute rise on the arcuate artery RI. In conclusion, peak levels of tacrolimus can cause the vasoconstriction of transplant-renal arterioles.