Evaluation of Indication Biopsies ≥5 Years After Kidney Transplant: A Single-Center Experience.

OBJECTIVES: Rejection is a common cause of late graft dysfunction seen on biopsy studies. The aim of this study was to evaluate indication biopsy findings ? 5 years after kidney transplant and to assess the effectiveness of applied treatments. MATERIALS AND METHODS: Between January 2013 and December 2015, 30 patients who underwent renal transplant indication biopsies and were followed up for ≥ 6 months were evaluated retrospectively. A >30% increase in serum creatinine and/or development of > 1 g/day proteinuria was considered an acceptable indication for biopsy. RESULTS: Of the 156 indication biopsies obtained within a 3-year period, 30 of them were indication biopsies performed ≥ 5 years after transplant. Twenty patients (67%) demonstrated late graft rejection, 6 patients (20%) had recurrent or de novo glomerulonephritis, and 4 patients (13%) were diagnosed with idiopathic chronic allograft nephropathy. The mean total histologic score was 6.2 ± 2.6, and the chronicity rate was 70%. For patients with late rejection, treatment consisted of pulse steroids in 11, intravenous immunoglobulin in 5, plasmapheresis in 4, antithymocyte globulin in 3, and rituximab in 2 cases. Five patients with glomerulonephritis received pulse steroids, 1 received rituximab therapy, and 3 were treated with cyclophosphamide. The mean follow-up after indication biopsy was 16 ± 11 months. Eleven patients (37%) had a progressive disease course and 7 patients (23%) resumed hemodialysis. Of the 30 patients, the 15 whose glomerular filtration rate was < 30 mL/min/1.72 m² at biopsy were more likely to have a progressive disease course (53% vs. 20%; P = .05) and more commonly resumed dialysis (40% vs. 7%; P = .03). CONCLUSIONS: Rejection was the most common cause of graft dysfunction long term. Chronic histologic changes predominated in indication biopsies ≥ 5 years posttransplant. Regardless of diagnosis, a low glomerular filtration rate at biopsy was closely associated with poor renal outcomes.