이식신의 급성 거부반응에서 도플러 초음파검사의 유용성

Abstract

After renal transplantation, early and accurate detection of acute renal allograft rejection and the differentiation of this abnormality from other forms of allograft dysfunction are important so that appropriate therapy can be instituted promptly. The study group consisted of 76 examinations in 51 patients with clinically suspected acute rejection episode who had undergone percutaneous renal biopsy between October 1989 and March 1996. The results of 76 duplex studies were compared with each patient's clinical course and histological findings. Two methods were used to evaluate the Doppler velocity waveform from arcuate arteries of allograft: (l)the resistive index(RI), (2)the end diastolic to peak systolic velocity ratio(D/S). RI and D/S in patients with acute rejection(N=55, 72%) averaged 0.78 and 0.22，respectively ； in patients with cyclosporin-A nephrotoxicity(N= 10, 13%), 0.71 and 0.32.; in patients with acute tubular necrosis(N= 11. 15%), 0.64 and 0.35. RI>0.55 was 73.3% predictive of acute rejection, with 100% sensitivity and 0.05% specificity. Using RI>0.85, predictive value,sensitivity and specificity for acute rejection were 100%, 27.3%, and 100%, respectively. D/S<0.45 was 73.3% predictive of acute rejection, with 100% sensitivity and 0.05% specificity. Using D/S< 0.15，predictive value, sensitivity and specificity for acute rejection were 100%, 27.3%, and 100%, respectively. Our results show that renal transplant dysfunction with RI>0.85 and/or D/S<0.15 are highly predictive of acute rejection. But sensitivity is very low (27.3%, respectively). Although duplex sonography cannot yet discriminate between acute rejection and cyclosporin nephrotoxicity or acute tubular necrosis accurately enough to avoid the renal biopsy, this is a noninvasive test which can be repeatedly performed and can help in the interpretation of clinically confusing situations of allograft dysfunction.