COVID-19–Associated Kidney Injury: A Case Series of Kidney Biopsy Findings

Abstract

BackgroundReports show that AKI is a common complication of severe coronavirus disease 2019 (COVID-19) in hospitalized patients. Studies have also observed proteinuria and microscopic hematuria in such patients. Although a recent autopsy series of patients who died with severe COVID-19 in China found acute tubular necrosis in the kidney, a few patient reports have also described collapsing glomerulopathy in COVID-19.MethodsWe evaluated biopsied kidney samples from ten patients at our institution who had COVID-19 and clinical features of AKI, including proteinuria with or without hematuria. We documented clinical features, pathologic findings, and outcomes.ResultsOur analysis included ten patients who underwent kidney biopsy (mean age: 65 years); five patients were black, three were Hispanic, and two were white. All patients had proteinuria. Eight patients had severe AKI, necessitating RRT. All biopsy samples showed varying degrees of acute tubular necrosis, and one patient had associated widespread myoglobin casts. In addition, two patients had findings of thrombotic microangiopathy, one had pauci-immune crescentic GN, and another had global as well as segmental glomerulosclerosis with features of healed collapsing glomerulopathy. Interestingly, although the patients had confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by RT-PCR, immunohistochemical staining of kidney biopsy samples for SARS-CoV-2 was negative in all ten patients. Also, ultrastructural examination by electron microscopy showed no evidence of viral particles in the biopsy samples.ConclusionsThe most common finding in our kidney biopsy samples from ten hospitalized patients with AKI and COVID-19 was acute tubular necrosis. There was no evidence of SARS-CoV-2 in the biopsied kidney tissue.

Multicenter Clinicopathologic Correlation of Kidney Biopsies Performed in COVID-19 Patients Presenting With Acute Kidney Injury or Proteinuria

“…49,50 Therefore, these delays meant that most patients in our cohort may have cleared virus from their kidney and were therefore RT-PCR negative by nasopharyngeal J o u r n a l P r e -p r o o f swab at the time of biopsy. Even with this caveat, most recent biopsy and autopsy case series have concluded that there is no significant SARS-CoV-2 infection of the kidney, 16,20,24,48,[51][52][53] which is in contrast to the possibility of direct infection that was reported in two earlier studies. 11,45 Therefore, our study adds to the accumulating evidence that direct and persistent infection of the kidney by SARS-CoV-2 does not appear to play a significant role in kidney disease in most COVID-19 patients.…”

Outcomes Among Patients Hospitalized With COVID-19 and Acute Kidney Injury

“…While in some cases the injury was mild, in many cases patients developed acute tubular injury with or without concomitant pathology including collapsing glomerulopathy or rarely thrombotic microangiopathy. [30][31][32][33] Second, it is important to understand the degree to which post-hospital nephrology follow-up care may be required, and accordingly the potential burden that COVID-19 conveys on the nephrology community. Third, for patients with AKI-KRT, knowledge on recovery and the ability to be discharged off dialysis can influence in-hospital decision making.…”

KIM-1/TIM-1 is a Receptor for SARS-CoV-2 in Lung and Kidney

“…This would be reminiscent of the use of Enfuvirtide, Maraviroc and Ibalizumab for HIV where administration of agents that will bind to the virus in the circulation will compete for tissue binding (Henrich and Kuritzkes, 2013). At the present time there is controversy with respect to the presence of SARS-CoV-2 nuclear capsid protein immunoreactivity in kidney tissue of subjects with documented infection with some investigators reporting its presence (Braun et al, 2020;Puelles et al, 2020) and others not finding evidence for virus in autopsy specimens (Santoriello et al, 2020;Sharma et al, 2020). SARS-CoV-2 RNA has been reported in 38 of 63 post-mortem kidneys of patients who had SARS-CoV-2 respiratory infection (Braun et al, 2020).…”