Distinguishing age-related from disease-related XXXX on kidney biopsy: the Aging Kidney Anatomy study.

@entity82 @entity550 @entity101 @entity3808 @entity740 @entity631
BACKGROUND: @entity631 is characteristic of @entity740 and also occurs with normal aging. Our goal was to determine the upper limit of normal for number of @entity3808 . METHODS: Core-needle biopsies of the renal cortex were obtained at the time of living kidney transplantation at three centers between 1998 and 2011. The number of @entity3808 was averaged across two biopsy sections. Quantile regression was used to estimate the 95th percentile for @entity3808 as the upper reference limit. There were 2052 donors (mean age 43 years, 41% male, 10% @entity101 ), with a mean (SD) of 16.0 (9.7) glomeruli and 0.47 (0.99) @entity3808 on biopsy; only 2.6% had >5% @entity82 . RESULTS: In a multivariable model excluding @entity101 donors, independent predictors of the number of @entity3808 were age, total number of @entity550 . A simplified model was used to estimate the 95th percentile for number of @entity3808 by total number of glomeruli and age. For a biopsy section with 17-32 total glomeruli, the 95th percentile ranged from 1 for a 20-year old to 5.5 for a 70-year old donor. @entity101 donors were more likely to have an abnormal number of @entity3808 (OR = 1.79, P = 0.035). CONCLUSIONS: We have derived the 95% reference limit for number of @entity3808 in ostensibly healthy individuals accounting for age and the biopsy characteristics. Numbers of @entity3808 in a kidney biopsy that exceed these thresholds suggest chronic pathological injury in excess of that expected with normal aging.
