Renal biopsy in very elderly patients (over 80 years): clinical presentation, histological diagnosis, and long-term outcome.

Data regarding the long-term outcome of very elderly (VE) patients undergoing renal biopsy (RB) are lacking. The objective of this study was to analyse the outcome of VE patients undergoing RB. All patients over 65 years that underwent native RB between 2004 and 2016 in our center were included. Among the 206 included patients, those over 80 years (VE, 46 patients) were analysed and compared to those aged 65-80 years (160 patients). The outcomes of the VE group were analysed. Baseline characteristics, renal presentation, safety of RB and RB-related diagnosis were not different between VE patients and 65-80-year-old patients. Survival of VE patients was 73.1, 50.6 and 21.8% at 2, 4 and 6 years after RB, significantly poorer than those of 65-80-year-old group. Early death (< 1 year) occurred in 10 VE patients, was associated with a higher proteinuria-to-creatininuria ratio and tended to be associated with a more frequent dialysis need at RB. Of the 46 VE patients, 31 (67.4%) were diagnosed with a potentially reversible kidney disease, of whom 17 (40%) were started on immunosuppressive regimens. Survival of patients with a reversible kidney disease tended to be better than those with other diseases. RB appears as a safe and valuable procedure to assess diagnosis of kidney disease in VE patients. Our data suggest that RB is critical for the identification and treatment decision of patients with potentially reversible diseases and may translate in clinical improvement.