Rankin AJ, Cannon E, Gillis K, et al. - In patients with acute interstitial nephritis (AIN), researchers assessed the utility of histology in anticipating clinical outcomes. Between 2000 and 2015, adult renal biopsies yielding a diagnosis of AIN were re-examined. Participants in the study were divided into groups based on the percentage of non-fibrotic cortex containing inflammation (NFI-score), (NFI-1=0-24%, NFI-2=25-74%, NFI-3=75-100%), and the percentage of cortex containing tubular atrophy (TA score), (TA1=0-9%, TA2=10-24%, TA3=25-100%). There were 120 individuals with AIN and adequate data for analysis from a total of 2,817 native renal biopsies. A lower percentage of cortical tubular atrophy and, paradoxically, a higher percentage of inflammation in non-fibrosed cortex were related to an increased probability of a positive clinical result in patients with biopsy-proven AIN.