Kidney biopsy in the elderly: diagnostic adequacy and yield

Purpose The number of kidney biopsies (KB) performed in elderly patients has been increasing. Safety and usefulness of elderly KB have been well established, whereas much less is known about diagnostic adequacy and yield in this patient population. Methods We performed a retrospective study of KBs in 428 patients from April 2015 to December 2017 at an academic institution. We compared KB from 50 patients aged over 64 (elderly) with KB from 378 patients aged between 18 and 64. Results Gender ratio, body mass index, systolic and diastolic BP, creatinine values, incidences of AKI at the time of biopsy, INR/aptt values, and platelets were similar between the two groups. eGFR and number of transplant biopsies were lower in the elderly biopsy group. The glomerular yield was similar between the two groups (22 ± 14 vs. 22 ± 13, p = 0.869). The likelihood of obtaining more than ten glomeruli was 87% and 88%, respectively, without a significant difference. Inadequate samples were encountered in 6% of the elderly and 5.6% of the non-elderly KB, again without a significant difference. Samples taken by nephrologist had higher glomerular yield for both groups (25 ± 13 vs. 18 ± 12 overall, 26 ± 14 vs. 18 ± 14 for elderly, p