Renal histology in the elderly: indications and outcomes.

Background: Renal disease is being increasingly diagnosed in the elderly. However, reports on biopsy-confirmed renal disease in this population are limited. The aim of this study was to give an overview of the most important indications, diagnoses and outcomes of renal biopsies in the elderly in our center.

Methods: This was a retrospective review of all elderly renal biopsies over 5 years. Patients were eligible for inclusion if they were aged ≥65 years and had had a native kidney biopsy performed. The data recorded included age, sex, indications for biopsy, histological diagnoses and outcomes.

Results: During this time, 1,372 native renal biopsies were performed. Of these, 236 (17%) were in patients aged ≥65 years; 150 male (64%) and 86 female (36%). The most common indications for biopsy were acute renal failure and nephrotic syndrome. Common diagnoses included pauci-immune crescentic glomerulonephritis, tubulointerstitial nephritis, membranous nephropathy, IgA nephropathy and chronic thrombotic microangiopathy. Long-term follow-up of 3 years was available for 102 patients; median serum creatinine at the time of biopsy was 427 µmol/L (interquartile range 204-702) and at 3 years post biopsy had fallen to 192 µmol/L (interquartile range 152-408).

Conclusions: In our center, 17% of native kidney biopsies are performed in elderly patients aged ≥65 years. In our experience, this procedure was safe and had a 97% diagnostic rate. The available follow-up data of patients suggest that renal histology is not only of benefit in diagnosis but also of potential value in terms of prognosis and treatment.