Cytotoxic CD8-positive T-lymphocyte infiltration in the lungs as a histological pattern of SARS-CoV-2 pneumonitis

Despite millions of PCR confirmed cases of severe acute tion, the long-term pathophysiological changes induced by this infection in the lungs and their relationship with possible immune triggers remain incompletely understood. Acute respiratory distress syndrome and subsequent respiratory failure are the most common causes of mortality in hospitalised patients. Severe lung tissue destruction can be due to an overactive immune system that far exceeds the harm that would have been caused by direct virus replication. This study extends our previous investigation and presents detailed histopathological findings on cryotransbronchial biopsy in patients with persistent (range 31-182 days) pneumonitis and severe interstitial inflammatory infiltration in the lungs due to SARS-CoV-2 infection. We describe a novel lung injury pattern associated with SARSCoV-2 pneumonitis, which manifests as a marked interstitial CD8-positive T-cell lymphocytic infiltration. These findings provide a better understanding of the changes in the lungs that ensue due to SARS-CoV-2 infection.

Automated summary

This study presents detailed histopathological findings on lung biopsy in patients with persistent pneumonitis and severe interstitial inflammatory infiltration due to SARS-CoV-2 infection. A novel lung injury pattern associated with SARS-CoV-2 pneumonitis, characterized by marked interstitial CD8-positive T-cell lymphocytic infiltration, is described. These findings contribute to a better understanding of the lung changes caused by SARS-CoV-2 infection.