Acute tubulointerstitial nephritis and COVID-19.

Coronavirus disease 2019 (COVID-19) is an ongoing pandemic that to date has spread to >100 countries. Acute kidney injury is not uncommon with this disease. The most common kidney biopsy finding is acute tubular injury. Glomerular diseases such as collapsing glomerulopathy and vasculitis, and thrombotic microangiopathy have been reported. Viral inclusion particles with distinctive spikes in the tubular epithelium and podocytes, and endothelial cells of the glomerular capillary loops, have been visualized by electron microscopy by some but disputed by others as non-viral structures. Interstitial infiltrates have not commonly been described in the published kidney biopsy series from patients with COVID-19. Medications used to treat COVID-19 can lead to interstitial nephritis, but very few have been reported. In summary, interstitial kidney disease is a rare finding in COVID-19.