The clinical usefulness of the renal allograft biopsy in the cyclosporine era - A prospective study

Background. The renal allograft biopsy is generally accepted as the gold st andard for clarifying the cause of renal dysfunction, However, the clinical usefulness of this procedure has rarely been studied prospectively, nor ha ve most studies included follow-up of patients to delineate the influence o f the biopsy on clinical outcome. In this study, we evaluated prospectively the clinical usefulness of the allograft biopsy in renal transplant recipi ents receiving cyclosporine (CyA). Methods. During a 21-month period, 82 biopsies were performed. In 54 instan ces (47 patients), we outlined a presumed diagnosis and tentative treatment plan before the procedure. After the biopsy, a definitive diagnosis was ma de and an appropriate patient management approach was instituted. We analyz ed the incidence of change in patient management that resulted from histolo gical findings. All patients were followed to monitor their response to tre atment and allograft survival. In cases of biopsy-proven acute cellular rej ection (ACR) or cyclosporine (CyA) toxicity, clinical and laboratory data f rom the day of the biopsy were reviewed to determine their diagnostic value . Results. One biopsy specimen was inadequate for definitive interpretation. The biopsy findings resulted in a change in patient management in 22 (41.5% ) of the remaining 53 cases (change group). The incidence of altered patien t management was 38.7% in biopsy specimens taken in the first month, 55.6% between 1 and 12 months, and 38.5% after 1 year posttransplantation. A chan ge in management was required in 2 of 2 patients with chronic allograft dys function, in 44.4% of the 45 patients with acute allograft dysfunction, and in none of the patients with delayed graft function (n=6), Within the firs t week of treatment 19 of 22 (86.4%) in the change group and 25 of 31 (80.6 %) in the no change group had a positive response to therapy. The 1-year al lograft survival rate was also similar between the two groups. None of the clinical and laboratory data was useful in distinguishing ACR from CyA toxi city. Conclusions. Renal allograft biopsy findings alter patient management recom mendations in approximately 40% of patients in whom a presumptive diagnosis had been made on the basis of clinical and laboratory findings. Patients w ho had a change in patient management because of biopsy findings demonstrat ed a response to therapy and allograft survival similar to those of patient s who had no alteration in management plan after the biopsy.