Early protocol renal allograft biopsies and graft outcome

To evaluate whether biopsies performed early after transplantation in stable grafts can predict graft failure due to chronic transplant nephropathy, a protocol biopsy was performed at three months in 98 patients treated with antilymphocytic antibodies, cyclosporine and prednisone. Patients were followed for 58 +/- 16 months. Histological diagnosis according to the Banff schema were: normal (N = 41), borderline changes (N = 12), chronic transplant nephropathy (CTN; N = 30), CTN associated to borderline changes (N = 11) and acute rejection (N = 4). Biopsies displaying acute rejection were nut considered for statistical analysis. Since clinical characteristics of patients with normal histology and borderline changes, as well as characteristics of patients displaying CTN either with or without tubulitis were not different, biopsies were grouped as presence or absence of CTN. Patients displaying CTN had an increased incidence of acute rejection before performing biopsy (24.3 vs. 3.9%, P = 0.003), a higher mean cyclosporine level until biopsy (242 +/- 74 vs. 214 +/- 59 ng/ml, P = 0.049) and a lower actuarial graft survival (80.5% vs. 94.4%, P = 0.024). We conclude that early protocol biopsies are useful to detect patients at risk of losing their graft due to chronic transplant nephropathy.