Researchers identify how SARS-CoV-2 impacts kidneys of patients hospitalized with COVID-19
Click Here to Manage Email Alerts
An analysis of patients who were hospitalized with COVID-19 in Belgium demonstrated SARS-CoV-2 caused specific manifestations of kidney proximal tubule dysfunction.
According to Alexis Werion, of Cliniques universitaires Saint-Luc in Brussels, and colleagues, this finding may provide important insights into associated patient outcomes, including which patients are at greatest risk for disease progression and respiratory failure.
“Increasing evidence suggests that COVID-19 may cause kidney damage, as indicated by the occurrence of proteinuria, hematuria and elevated serum creatinine on admission; the high incidence of acute kidney injury (AKI); and a spectrum of pathologic abnormalities including acute tubular necrosis, endothelial damage and capillary occlusions, deposition of complement complex on tubules, and glomerular lesions identified in autopsy report,” the researchers wrote. “Kidney damage may result from hemodynamic factors, dysfunctional immune responses, or direct viral infection of kidney cells, the latter being compatible with the detection of SARS-CoV-2 mRNA and protein in glomerular and tubular cells and of purported viral particles in podocytes and proximal tubule (PT) cells.”
To determine if patients with COVID-19 have specific manifestations of proximal tubule dysfunction, the researchers assessed 49 patients who were not on renal replacement therapy at the time of hospital admission (median age, 64 years; 69% were men; 86% were white). Patients were admitted a median 7 days after the onset of symptoms, which mostly consisted of fever, dyspnea and cough.
Urinalyses were performed a median of 9 days after admission to determine the occurrence and pattern of proximal tubule dysfunction, with researchers observing that 69% of the study population had elevated urinary levels of 2-macroglobulin, 85% had a urinary protein to creatinine ratio of greater than 0.2 g/g and 98% had a urinary albumin to protein ratio of less than 0.5.
Findings indicated a presence of proximal tubule dysfunction in patients with the virus, as demonstrated by low-molecular-weight proteinuria, neutral aminoaciduria and defective handling of uric acid or phosphate, according to the researchers.
Werion and colleagues further found the kidneys of these patients showed prominent tubular injury, noting specific features of the dysfunction were associated with disease severity and with an increase in the risk for respiratory failure requiring mechanical ventilation (adjusted hazard ratio= 6.2).
“In summary, SARS-CoV-2 infection causes an early and specific dysfunction of the kidney PT characterized by [low-molecular-weight] LMW proteinuria, defective tubular handling of uric acid and phosphate and neutral aminoaciduria,” the researchers concluded. “These data provide novel insights into the pathophysiology of COVID-19 and open perspectives for biomarkers of disease severity.”
Collapse
Read more about
Click Here to Manage Email Alerts