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.