Renal biopsy in the very elderly

Abstract

Background and objectives: Data regarding renal biopsy in the very elderly (>or=age 80 yr) are extremely limited. The aim of this study was to examine the causes of renal disease and their clinical presentations in very elderly patients who underwent native renal biopsy.

Design, setting, participants, & measurements: All native renal biopsies (n = 235 including 106 men, 129 women) performed in patients aged >or=80 yr over a 3.67-yr period were retrospectively identified. Results were compared with a control group of 264 patients aged 60 to 61 who were biopsied over the same period.

Results: The indications for biopsy were acute kidney injury (AKI) in 46.4%, chronic-progressive kidney injury in 23.8%, nephrotic syndrome (NS) in 13.2%, NS with AKI in 9.4%, and isolated proteinuria in 5.5%. Pauci-immune GN was the most frequent diagnosis (19%), followed by focal segmental glomerulosclerosis secondary to hypertension (7.6%), hypertensive nephrosclerosis (7.1%), IgA nephropathy (7.1%) and membranous nephropathy (7.1%). Comparison with the control group showed pauci-immune GN to be more frequent (P < 0.001) and diabetic glomerulosclerosis (P < 0.001) and membranous nephropathy (P < 0.05) less frequent in the very elderly. Diagnostic information had the potential to modify treatment in 67% of biopsies from the very elderly, particularly in those with AKI or NS.

Conclusions: Renal biopsy in very elderly patients is a valuable diagnostic tool that should be offered in clinical settings with maximal potential benefit. Advanced age per se should no longer be considered a contraindication to renal biopsy.

Figure 1.

Distribution of very elderly patients who underwent renal biopsy by age and gender.

Figure 2.

Indications for renal biopsy. AKI, acute kidney injury; CKI, chronic-progressive kidney injury; NS, nephrotic syndrome; Prot, proteinuria; Hem, hematuria.

Figure 3.

Most common biopsy diagnoses. Biopsies with double diagnoses are excluded. pi GN, pauci-immune GN; 2o FSGS HTN, focal segmental glomerulosclerosis (FSGS) secondary to hypertension/aging; HTN, hypertensive nephrosclerosis; IgA, IgA nephropathy; MN, membranous nephropathy; Amyl, amyloidosis; MCD, minimal change disease; Myel Cast, myeloma cast nephropathy.

Figure 4.

Most common diagnoses, showing control comparison with 60- to 61-yr-old patients. Biopsies with double diagnoses are excluded. pi GN, pauci-immune GN; 2o FSGS HTN, FSGS secondary to hypertension/aging; MN, membranous nephropathy; HTN, hypertensive nephrosclerosis; Amyl, amyloidosis; MCD, minimal change disease; Myel Cast, myeloma cast nephropathy; Diab GS, diabetic glomerulosclerosis, AIN, acute interstitial nephritis; CTIN, chronic tubulointerstitial nephropathy; 1o FSGS, primary FSGS; 2o FSGS obesity, FSGS secondary to obesity. * indicates highly significant comparison (P < 0.001), + indicates significant comparison (P < 0.05).