Duodenal histologic findings in patients with history of COVID-19 infection

Abstract: Background: While the SARS-COV2 infection affects mainly the respiratory system, there is more evidence on the gastrointestinal (GI) involvement. However, data on the pathophysiology of infection and the secondary immune response on intestinal level are still scarce. Our study aims at describing duodenal histologic findings in patients with history of COVID-19 infection. Methods: Between January 2021 and May 2021, we included patients with history of SARS-COV2 infection over the last 6 months and who underwent an upper GI endoscopy and duodenal biopsies (Group 1). We also selected a control group of uninfected patients (Group 2) who had an upper endoscopy during the same period. Standard anatomopathological analysis was done followed by immunohistochemistry to identify the lymphocytic phenotype notably the CD8+ T cells. We then tried to correlate histologic abnormalities to patients’ characteristics. Results: Twenty-five patients were included in the Group 1 with a mean age of 46 years and female predominance (52%). The indication of endoscopy was mainly related to abdominal pain and diarrhea (64 and 25% of cases, respectively). The average time from the disease onset was 74.5 days. 45% of patients experienced GI symptoms during their infection mostly diarrhea and abdominal pain. On duodenal biopsies, intra-epithelial lymphocytes (IEL) count was elevated (>20/100 enterocytes) in 60% of cases and CD8+ cells were found in 48% of patients in group 1. We did not find any correlation between these abnormalities and the presence of GI symptoms. Ten patients were included in Group 2, only one had increased IEL count (20/100EC) and negative for CD8+ T cells on duodenal biopsies. Conclusion: The duodenal biopsy in patients with history of COVID-19 infection shows an increased IEL count as well as CD8+ T cells even few months after the disease onset