Flow-cytometric measurement of cellular changes in urine: A simple and rapid method for perioperatively monitoring patients after kidney transplantation

Objective: In renal transplant patients having graft dysfunction, it is usu ally difficult to obtain the accurate diagnosis, such as acute rejection, a cute tubular necrosis, infection, or ciclosporin nephrotoxicity. An accurat e diagnosis can provide the proper treatment of these patients, thereby les sening the chance of kidney loss. Methods: A total of 42 patients were enro lled. By using the flow-cytometric technique, the white cell populations of urine in these patients were analyzed and linked to their clinical course. All patients underwent sonography-guided biopsy of the transplanted kidney with a definitive diagnosis. Results: When 10% lymphocytes and 15% granulo cytes in urine were set as the cutoff point of a normal ratio threshold, th e flow-cytometric analysis presented the highest sensitivity and the highes t negative predictive rate for acute tubular necrosis. However, a lower sen sitivity and positive predictive rate was found in acute rejection cases. C onclusions: Our results suggest that flow-cytometric analysis of the urinar y cell population can be used as an adjunct in patient follow-up after kidn ey transplantation.