Methods:
This single center study included 49 cases of onset or aggravation of
kidney injury associated with COVID-19 infection between December 2022
and March 2023 in Nephrology Institute of the Second Xiangya Hospital
ofCentral South University. 38 of them performed kidney biopsy.Inclusion
criteria included cases with a confirmed COVID-19 infection by RNA PCR
or antigen detection within one week before or after kidney injury.
Patients were divided into 2 groups: Group A for patients with onset of
kidney injury after SARS CoV-2 infection; Group B for patients with
pre-existing kidney disease who experienced aggravation of renal
insufficiency after SARS-CoV-2 infection.
Kidney biopsy sections were stained with hematoxylin and eosin(H&E),
Periodic acid-Schiff(PAS),Masson-Trichrome, Periodic-acid silver
methenamine (PASM), and Congo Red and examined by light microscopy.
Immunofluorescence(IF) staining was performed for IgG, IgA, IgM, C3,
C1q, Kappa light chain and Lambda light chain.All cases were diagnosed
by nephropathologist.