Aki in the setting of COVID-19: Histopathologic and ultrastructural findings in postmortem kidney biopsy

Background: COVID-19 has been associated with a very high risk of AKI The pathophysiology of the AKI is unclear with conflicting reports regarding the presence of direct infection of the kidney with SARS-CoV2 Methods: Postmortem kidney biopsy was performed in adult patients with confirmed COVID-19 and stage 2 /3 AKI Biopsies were examined using light and electron microscopy Immunohistochemistry and RNA in situ hybridization were performed for SARS-CoV2 Results: 12 patients (83% male) with mean age of 70±13 years underwent biopsy Mean baseline and peak creatinine were 1 0 and 5 3 mg/dL, respectively Renal replacement therapy was required in 8 (67%) patients (Table 1) All 12 patients had a pathologic diagnosis of acute tubular injury with focal acute tubular necrosis (Table 2) There was no glomerulitis, vasculitis, or thrombotic microangiopathy There were no characteristic viral particles on electron microscopy and there was no evidence of SARSCoV- 2 on Immunohistochemistry or in situ RNA hybridization Conclusions: AKI in patients with COVID-19 infection was associated with acute tubular injury and focal epithelial necrosis in all patients There was no evidence of direct viral infection It appears unlikely that SARS-CoV-2 causes renal injury by direct infection