Introduction:
Since December 2019, a new respiratory infectious disease ‘COVID-19’ has become a global epidemic. Kidney is one of the most frequently involved extrapulmonary organs. The renal injury caused by SARS CoV-2 is called COVID-19 associated nephropathy (COVAN), which is related to the poor prognosis of patients. Renal injury usually manifests as nephritis, recurrence or aggravation of kidney disease, transplant rejectionand acute kidney injury (AKI). The mortality rate of COVID-19 cases with AKI is significantly higher than those without kidney disease[1]. According to current reports, COVID-19 associated kidney injury has multiple pathological manifestations, including collapsed glomerulonephritis (CG), acute interstitial nephritis (ATI), focal segmental glomerulosclerosis(FSGS) and thrombotic microvascular disease (TMA). CG is reported to be the most characteristic manifestation after SARS-CoV-2 infection[2].
Since the first pandemic of wild-type SARS-CoV-2in 2019, the strains have gradually mutated into Alpha, Beta, gamma, Delta and other strains. By 2022, COVID-19 virus has been compiled into the omicron variant. There have been plenty of reports on kidney injury caused by the early pandemic delta strain, while at present, the reports on the clinical and pathological characteristics of kidney injury caused by omicron infection are relatively lacking. Although a large number of studies on COVID-19 associated kidney injury have been reported abroad, the clinicopathological characteristics of COVID-19 associated kidney injury in China are different from those in foreign countries due to strain variation and ethnic differences. This study retrospectively included 49 COVID-19 associated kidney injury patients from the Second Xiangya Hospital of Central South University from December 2022 to March 2023, 38 of whomperformed kidney biopsy, and analyzed their clinical and pathological features to explore the characteristics and prognosis of COVID-19 associated kidney injury.