Digestive Symptoms of COVID-19 and High Expression of ACE2 in Digestive Tract Organs

Abstract

A novel coronavirus (SARS-CoV-2) was identified in December 2019, Wuhan, China. This new coronavirus has resulted in numerous cases of Coronavirus Disease 2019 (COVID-19) throughout the world. Apart from fever and respiratory symptoms, digestive symptoms could be observed in patients with COVID-19. Angiotensin-converting enzyme 2 (ACE2) was reported to be the receptor of SARS-CoV-2. Aim to more comprehensively investigate the digestive symptoms in COVID-19 patients, and the potential pathogenic route of the SARS-CoV-2 infection in digestive tract organs (from oral cavity to gut), we investigated the digestive symptoms of 48 patients with COVID-19, and explored ACE2 expression in digestive tract cancers and lung cancers, based on a series of bulk and single-cell RNA sequencing data from public databases. We found that 25% (12/48) patients with COVID-19 suffered from digestive symptoms, among which pharyngalgia (7/48) was the most common manifestation, followed by diarrhea (3/48), anorexia (3/48), and nausea (1/48). The bulk RNA sequencing analysis indicated that digestive tract organs had higher ACE2 expression than lung and expression of ACE2 in lung increases with age. Single-cell RNA-Seq results showed that ACE2-positive-cell ratio in digestive tract organs was significantly higher than that in lung; ACE2 expression was higher in tumor cells than that in NC tissues; in gastric tissues, ACE2 expression was gradually increased from chronic gastritis, metaplasia to early cancer. Our data may provide a theoretical basis for the screening of SARS-CoV-2 susceptible population, and for the clinical classification for treatment of patients with COVID-19. Funding Statement: This work was supported by the Guangdong Financial Fund for High-Caliber Hospital Construction. Declaration of Interests: The authors have no conflicts of interest. Ethics Approval Statement: This study was approved by the institutional ethics board of Guangzhou Eighth People’s Hospital (No. 202006139).