Prognostic Assessment of Histopathologic Lesions in Patients with Community-Acquired AKI with Biopsy-Proven Acute Tubular Necrosis

Key Points The severity of acute tubular necrosis was closely associated with renal survival. Crescent and arterial lesions are significantly associated with progression to ESKD and exerted superimposing effects together with acute tubular necrosis. Tubular atrophy/interstitial fibrosis and intracapillary lesions increase the risk of CKD stage 3–5. Background Community-acquired AKI (CA-AKI) was more likely to be comorbid with underlying kidney histopathological lesions in addition to acute tubular necrosis (ATN). Thus, we tried to clarify the histological determinants that could influence the prognosis and recovery of patients with CA-AKI with biopsy-proven ATN. Methods Adult patients with CA-AKI with biopsy-proven ATN who underwent renal biopsy at Shanghai Changzheng Hospital from January 1, 2010, to December 31, 2018, were included and followed up for 5 years. The impacts of histopathological lesions on short-term and long-term renal dysfunction were also analyzed. Results Multivariate analysis revealed that ATNs, crescents, and decrease of arteriole lumens increased short-term dialysis requirements. The severity of ATN was closely associated with renal survival. According to the Kaplan–Meier analysis, the severity of ATN was significantly associated with short-term dialysis needs and long-term development of ESKD during follow-up. Crescent and decrease of arteriole lumens are significantly associated with progression to ESKD and exert synergistic effects with ATN. For patients who did not progress to dialysis, tubular atrophic/interstitial fibrosis and endocapillary lesions were more relevant to partial recovery of renal function after CA-AKI at the 3-month follow-up and increased the risk of CKD stage 3–5 at the 5-year follow-up. According to our correlation analysis, endocapillary lesions and crescents were positively correlated with ATN. Conclusions Histopathologic lesions, apart from tubular necrosis, contributed to the detrimental short-term and long-term renal prognosis of patients with CA-AKI with ATN; concomitant histopathologic lesions exerted a combined impact on renal survival together with ATN in patients with CA-AKI.