[Color-coded Doppler ultrasonography in early detection of rejection reactions after allogeneic kidney transplantation]

A prospective study of 45 consecutive patients (27 men, 18 women, mean age 42 [22-64] years) who had undergone allogeneic renal transplantation was carried out to ascertain whether rejection of the graft can be detected by routine follow up with colour-coded Doppler ultrasonography even in the presence of acute renal failure requiring dialysis. Conventional diagnostic methods detected 44 episodes of rejection in 33 patients: 26 of these arose in 18 patients with acute renal failure requiring dialysis and 18 in 15 patients who did not require dialysis. Colour-coded Doppler ultrasonography was used to determine the "pulsatility index" (PI) at intervals of 3 to 6 days. 17 of the 18 episodes of rejection occurring in transplant patients with stable serum creatinine levels (3.41 +/- 1.48 mg/dl) were detected by colour-coded Doppler ultrasonography 3.8 +/- 5.6 days earlier than by conventional diagnostic methods, the indicator being the rise in PI (sensitivity 93.8%). 25 of the 26 rejection reactions which arose in patients with oligo-anuria due to post-operative renal failure were detected 2.0 +/- 2.7 days earlier (sensitivity 96%). The rise in PI was greater in episodes of vascular rejection than in purely interstitial rejection episodes (40.9 +/- 73.9% versus 10.0 +/- 8.8% per day). Colour-coded Doppler ultrasonography ia a new, highly sensitive, noninvasive method for the early detection of rejection reactions after renal transplantation. Acute postischaemic renal failure does not reduce its sensitivity.