Early detection of acute rejection in renal allografts using radioiodinated autologous fibrinogen.

131I-labeled autologous fibrinogen was used to detect acute renal allograft rejection in the early postoperative period. Ratios of radioactive counts over transplanted kidneys to those over the heart increased with deposition of radioactive fibrinogen in kidneys undergoing rejection. The test was positive in all instances of acute rejection twelve to twenty-four hours prior to clinical ro biochemical changes. False-positive test results were noted in instances of perinephric hematoma, seroma, and wound abscess and in one patient with urinary tract infection. The test was negative in cases of renal failure secondary to acute tubular necrosis, uric acid nephropathy (in the absence of acute rejection), and chronic rejection. This test is simple, rapid, and practical. It can be performed at the bedside and is free from complications, particularly serum hepatitis.