The Renal Histopathology Spectrum of Elderly Patients with Kidney Diseases: a Study of 430 Patients in a Single Chinese Center

The elderly population has significantly increased in China. However, data regarding renal histopathology in this population is lacking. The present study retrospectively analyzed renal disease spectrum of 430 elderly patients who had received renal biopsy at Peking University First Hospital between January 2003 and December 2012. Among 6049 patients receiving renal biopsies during the same period, 430 (7.10%) were elderly (≥65 years). The ratio of male (263 patients) to female (167 patients) was 1.57:1, with an age of 70.29±3.99 (range 65-82) years at the time of biopsy. The most common indication for renal biopsy was nephrotic syndrome (59.53%), followed by acute kidney injury (AKI, 19.53%) and chronic glomerulonephritis (CGN, 16.05%). The most common renal histopathology in primary glomerular disease was idiopathic membranous nephropathy (iMN, 61.02%), followed by IgA nephropathy (18.22%), minimal change disease (MCD, 9.32%) and focal segmental glomerulosclerosis (6.78%). ANCA-associated vasculitis (AAV, 43.95%) was the leading secondary glomerular disease, followed by HBV-related glomerulonephritis (HBV-GN, 24.2%), and amyloidosis (14.01%). In patients with nephrotic syndrome, iMN (50%) was the leading cause, followed by HBV-GN (16.02%), MCD (7.81%), and amyloidosis (7.81%). In patients with iMN, 89.5% presented as nephrotic syndrome, 8.39% as CGN. In patients with AKI, the leading cause was AAV (48.12%), followed by acute interstitial nephritis (20.48%) and acute tubular necrosis (8.43%). In conclusion, in elderly Chinese patients, the most common renal histopathology pattern was iMN in patients with nephrotic syndrome, and AAV in patients with AKI.