The spectrum of kidney biopsies in hospitalized patients with COVID-19, acute kidney injury, and/or proteinuria

Ferlicot, Sophie; Jamme, Matthieu; Gaillard, François; Oniszczuk, Julie; Couturier, Aymeric; May, Olivia; Grünenwald, Anne; Sannier, Aurélie; Moktefi, Anissa; Le Monnier, Ophélie; Petit-Hoang, Camille; Maroun, Nadine; Brodin-Sartorius, Albane; Michon, Arthur; Dobosziewicz, Hélène; Andreelli, Fabrizio; Guillet, Matthieu; Izzedine, Hassane; Richard, Christian; Dekeyser, Manon; Arrestier, Romain; Sthelé, Thomas; Lefèvre, Edouard; Mathian, Alexis; Legendre, Christophe; Mussini, Charlotte; Verpont, Marie-Christine; Pallet, Nicolas; Amoura, Zahir; Essig, Marie; Snanoudj, Renaud; Brocheriou-Spelle, Isabelle; François, Hélène; Belenfant, Xavier; Geri, Guillaume; Daugas, Eric; Audard, Vincent; Buob, David; Massy, Ziad A; Zaidan, Mohamad

We report a multicentric retrospective case series of patients with COVID-19 who developed acute kidney injury and/or proteinuria and underwent a kidney biopsy in the Paris and its metropolitan area. Forty-seven patients (80.9% men) with COVID-19 who underwent a kidney biopsy between March 08 and May 19, 2020 were included. Median age was 63 years IQR [52–69]. Comorbidities included hypertension (66.0%), diabetes mellitus (27.7%), obesity (27.7%), history of chronic kidney (25.5%), cardiac (38.6%) and respiratory (27.3%) diseases. Initial symptoms were fever (85.1%), cough (63.8%), shortness of breath (55.3%), and diarrhea (23.4%). Almost all patients developed acute kidney injury (97.9%) and 63.8% required renal replacement therapy. Kidney biopsy showed two main histopathological patterns, including acute tubular injury in 20 (42.6%) patients, and glomerular injury consisting of collapsing glomerulopathy and focal segmental glomerulosclerosis in 17 (36.2%) patients. Two (4.3%) patients had acute vascular nephropathy, while eight (17%) had alternative diagnosis most likely unrelated to COVID-19. Acute tubular injury occurred almost invariably in the setting of severe forms of COVID-19, whereas patients with glomerular injury had various profiles of COVID-19 severity and collapsing glomerulopathy was only observed in patients harboring a combination of APOL1 risk variants. At last follow-up, 16 of the 30 patients who initially required dialysis were still on dialysis, and 9 died. The present study describes the spectrum of kidney lesions in patients with COVID-19. While acute tubular injury is correlated with COVID-19 severity, the pattern of glomerular injury is intimately associated with the expression of APOL1 risk variants.