Conclusion
This is the first study in the Indian population showing the in-situ presence of viral particles in core biopsies from fatal cases of COVID-19. As evident from the results, histology and ultrastructural changes in the lung correlated with the presence of viral particles. The study revealed a positive correlation between the damage in the lungs and the presence of viral particles.
Methods
The present study was conducted on samples obtained from reverse transcription-polymerase chain reaction (RT-PCR)-positive patients who were admitted to a tertiary care hospital in Western India. Core needle biopsies were done in eight fatal cases of COVID-19. The samples were taken from the lungs, liver, and brain and subjected to light microscopy, immunohistochemistry (IHC), and transmission electron microscopy (TEM). Clinical details and biochemical findings were also collected.
Results
The study participants included seven males and one female. The presenting complaints included fever, breathlessness, and cough. Light microscopy revealed diffuse alveolar damage in the lungs. Further, a positive expression of SARS-CoV-2 nucleocapsid protein was observed in the pulmonary parenchyma of five patients. Also, the TEM microphotograph showed viral particles of size up to 80nm localized in alveolar epithelial cells. However, no viral particles were found in liver or brain samples. In the liver, macrovesicular steatosis and centrizonal congestion with loss of hepatocytes were observed in light microscopy.