Clinical and pathological features of omicron variant of SARS‐CoV‐2‐associated kidney injury

Abstract

AbstractKidney injury is common in patients with Coronavirus Disease‐19 (COVID‐19), which is related to poor prognosis. We aim to summarize the clinical features, athological types, and prognosis of COVID‐19 associated kidney injury caused by the Omicron strain. In this study, 46 patients with Omicron‐associated kidney injury were included, 38 of whom performed renal biopsy. Patients were divided into two 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. The clinical, pathological, and prognostic characteristics of the patients were observed. Acute kidney injury (AKI) (35%) was the most common clinical manifestation in group A. Patients in group B mainly presented with chronic kidney disease (CKD) (55%) and nephrotic syndrome (NS) (40%). The pathological type was mainly IgA nephropathy (IgAN) (39% in group A and 45% in group B). Among all of them, one case presenting with thrombotic microangiopathy had worse kidney function at biopsy time. Mean serum C3 levels were 1.2 ± 0.5 and 1.0 ± 0.2 g/L in group A and group B, respectively. In renal tissues, C3 deposits were observed in 71.1% of patients. 11.8% (n = 2) patients experienced deterioration of renal function after treatment, but no patients developed to end‐stage renal disease. In our single‐center study in China, the main clinical manifestations were AKI, CKD, and NS, while the main pathological type was IgAN. Compared with previous strains of SARS‐CoV‐2, patients with the Omicron infection had a favorable prognosis.