We’ve rebranded some of our products, learn more ›

CODEX® is now PhenoCycler,
Phenoptics™ is now Phenolmager.

Residual SARS-CoV-2 viral antigens detected in GI and hepatic tissues from five recovered patients with COVID-19

Authors: Cheung, Chun Chau Lawrence; Goh, Denise; Lim, Xinru; Tien, Tracy Zhijun; Lim, Jeffrey Chun Tatt; Lee, Justina Nadia; Tan, Benedict; Tay, Zhi En Amos; Wan, Wei Yee; Chen, Eileen Xueqin; Nerurkar, Sanjna Nilesh; Loong, Shihleone; Cheow, Peng Chung; Chan, Chung Yip; Koh, Ye Xin; Tan, Thuan Tong; Kalimuddin, Shirin; Tai, Wai Meng David; Ng, Jia Lin; Low, Jenny Guek-Hong; Yeong, Joe; Lim, Kiat Hon

Online: https://gut.bmj.com/content/early/2021/06/13/gutjnl-2021-324280

Issue: Gut. 2021 Jun 2;gutjnl-2021-324280.


We read with great interest the article published by Zuo et al , which highlighted the presence of SARS-CoV-2 RNA in stool samples during active and convalescence phases of COVID-19 infection.1 However, no study has reported the presence of viral antigens within GI and hepatic organs during the convalescent phase. Using conventional immunohistochemistry, we detected SARS-CoV-2 nucleocapsid protein (NP) in the colon, appendix, ileum, haemorrhoid, liver, gallbladder and lymph nodes (figure 1A–K) from five patients who recovered from COVID-19, ranging from 9 to 180 days after testing negative for SARS-CoV-2 (online supplemental table 1). Notably, when multiple tissues were obtained from one patient (patients 1 and 4), all the tissues showed the presence of the viral antigen, suggesting widespread multiorgan involvement of the viral infection. Interestingly, for the colon, the viral antigen was only present in normal colonic crypts and polyps but not in the neoplastic tissues (figure 1Q). Similar negative staining in the hepatocellular carcinoma tumour region was also observed (figure 1R) albeit the positive staining in some of the scattered immune cells (figure 1D). Validating our findings, we detected SARS-CoV-2 spike protein (figure 1L–P) and RNA (figure 2B–F) in the above-mentioned tissues using conventional immunohistochemistry and RNAscope, respectively. However, we were unable to detect viral RNA in some patients’ tissues (online supplemental table 1), possibly because of higher RNA degradation rate as compared with protein and other patient-dependent factors such as disease severity, time since recovery and basal metabolic rate.### Supplementary data [gutjnl-2021-324280supp001.pdf] Figure 1 Immunohistochemical staining of the SARS-CoV-2 nucleocapsid and spike proteins in intestinal and hepatic tissues. (A and B) Positive SARS-CoV-2 nucleocapsid protein (NP) staining in colonic crypts (A) and appendix (B), both with a granular supranuclear cytoplasmic pattern. (C) positive SARS-CoV-2 NP staining in scattered immune cells in haemorrhoid tissue (red …