Spectrum of Viral Load and Host Response Seen in Autopsies of SARS-CoV-2 Infected Lungs

The relationship of SARS-CoV-2 lung infection and severity of pulmonary disease is not fully understood. We visualized viral RNA by in situ hybridization and assessed the immune infiltrate using immunohistochemistry and total RNA sequencing on five COVID-19 positive patients. Patients with high levels of viral RNA showed hyaline membranes on histology, extensive pneumocyte loss, low T-cell numbers and were enriched for the interferon gene signature, while patients with lower levels of viral RNA showed lower numbers of T-cells and CD8 cells and were enriched for fibrosis-associated genes. The study highlights the need to assess both pulmonary viral load and immune response in patients with severe COVID-19 infection. Overall design: Autopsy samples from patients deceased due to SARS-Cov2 infection were collected for total RNA-seq analysis to assess viral load and immune response.