Role of Resistive Index Measurement in Diagnosis of Acute Rejection Episodes Following Successful Kidney Transplantation

Objective

This study was performed to evaluate the role of resistive index (RI) in the diagnosis of rejection episodes following successful kidney transplantation.

Materials and Methods

One hundred and one unrelated living first kidney allograft adult recipients (75 males and 26 females) of overall mean age of 39 years were enrolled and prospectively followed for 6 months. The measurement of RI by Doppler ultrasonography was performed in all patients on days 3 and 7 as well as at months 1, 3, and 6 in addition to when there was graft dysfunction. We determined serum creatinine and cyclosporine levels.

Results

Twenty-seven patients (26.7%) experienced 33 acute rejection episodes during the follow-up. There were significant differences between mean RI among patients with normal function vs rejection: 0.606 ± 0.065 vs 0.866 ± 0.083 (P < .05), respectively. Overall, elevated levels of cyclosporine, ischemic acute tubular necrosis (ATN), and renal artery thrombosis were observed in 8, 5, and 3 patients, respectively. No association was observed between these factors and RI.

Conclusions

RI was significantly higher in patients with acute rejection episodes. It had no association with ATN or cyclosporine toxicity. Hence, RI may be useful to diagnose acute renal allograft rejection following renal transplantation.