Abstract
Coronavirus disease 2019 (COVID-19) has threatened human health worldwide and could lead to multiple organs injury. However, the impact on the virus infecting the biliary system, especially the gallbladder, has remained unclear and no pathological evidence has been reported yet. A case of SARS-CoV-2 infection in a gallbladder with cholecystitis, which progressed rapidly to sepsis and required an emergency operation was investigated and reported. Clinical specimens of the COVID-19 patient including serum, oropharyngeal swabs, sputum, bile, abdominal drainage fluid, urine, stool, and gallbladder tissue were collected and tested for SARS-CoV-2 RNA using a quantitative polymerase chain reaction (qPCR) assay. Fresh normal gallbladder tissue and gangrenous gallbladder tissue were also collected for further research including hematoxylin and eosin (HE), immunohistochemistry (IHC), and immunofluorescent (IF) staining, and compared with the gallbladder from the COVID-19 patient. The bile, as well as the serum, oropharyngeal swabs, sputum, abdominal drainage fluid, urine, and rectal swabs were consecutively negative for SARS-CoV-2 RNA. The viral host receptor angiotensin-converting enzyme 2 (ACE2) was highly expressed in gallbladder epithelial cells, and viral nucleocapsid protein (NP) was visualized in the cytoplasm of gallbladder epithelial cells. Immune cells including CD2, CD3, CD4, CD8, CD20, CD38, CD68, and MPO were positive in gangrenous gallbladder tissues without SARS-CoV-2 infection, and were relatively downregulated in SARS-CoV-2 infective gallbladder tissue. This study provided evidence of SARS-CoV-2 infection in the gallbladder and verified that the gallbladder was one of the target organs that SARS-CoV-2 could attack and damage using ACE2 as a cell receptor. Due to the immune dysregulation involved, more vigilant management and early assessment is needed for COVID-19 patients with the comorbidity of cholecystitis.