Different viral doses of cytomegalovirus infection in the left and right colons

Abstract

Objective: To compare the differences in the detection rates of cytomegalovirus (CMV) infection between the left and right colons for guiding endoscopic biopsy-sites. Methods: The cases of colonic CMV infection confirmed by histology at the Peking Union Medical College Hospital from July 2015 to July 2018 were collected and analyzed. Splenic curvature was used as the dividing point between the left and right colons. The CMV inclusions were identified histologically, and the CMV infected cells were detected using immunohistochemistry (EnVision method). The numbers of infected cells in the left and right colons were compared by histological and immunohistochemical results. A total of 731 patients were identified. Ten of the 731 patients had histological specimens of both left and right colons and were confirmed with CMV EnVision immunohistochemical study. There were 25 biopsy or resection specimens. Seven patients were male and 3 were female, and their ages ranged from 29 to 66 years, with a median age of 55 years. All of the 10 patients were also diagnosed with ulcerative colitis. Results: The number of the cells infected with CMV in the left colon was 115 (1-41), while that in the right colon was 76 (0-51). In 8/10 cases, the number of CMV infected cells in the left colon was more than that in the right colon. Conclusions: The study on the biopsies and resection specimens suggests that CMV infection is mostly present in the left colon. The left colon thus might be an important endoscopic biopsy-site for the cases with suspicion of CMV infection.