Limits of clinical signs and non-invasive techniques in detecting severe acute rejection.

We describe a cadaveric renal transplant patient with an early post-transplant period characterized by normal urine output, normal clinical and biological signs, and a slow decrease of serum creatinine; repeated ultrasonography, color doppler ultrasonography and renal angioscintigraphy were normal or consistent with a clinical diagnosis of mild acute tubular necrosis. Nevertheless a core renal biopsy revealed severe steroid-resistant acute rejection with diffuse infiltrates of lymphocytes and initial transmural arteritis.