1. Dinesen LC, Walsh AJ, Protic MN, et al. The pattern and outcome of acute severe colitis. J Crohns Colitis 2010;4:431-437.
2. Cesarini M, Collins GS, Rönnblom A, et al. Predicting the individual risk of acute severe colitis at diagnosis. J Crohns Colitis 2017;11:335-341.
3. Turner D, Walsh CM, Steinhart AH, Griffiths AM. Response to corticosteroids in severe ulcerative colitis: a systematic review of the literature and a meta-regression. Clin Gastroenterol Hepatol 2007;5:103-110.
5. Lindgren SC, Flood LM, Kilander AF, Löfberg R, Persson TB, Sjödahl RI. Early predictors of glucocorticosteroid treatment failure in severe and moderately severe attacks of ulcerative colitis. Eur J Gastroenterol Hepatol 1998;10:831-835.
6. Jain S, Kedia S, Bopanna S, et al. Faecal calprotectin and UCEIS predict short-term outcomes in acute severe colitis: prospective cohort study. J Crohns Colitis 2017;11:1309-1316.
7. Le Baut G, Kirchgesner J, Amiot A, et al. A scoring system to determine patients’ risk of colectomy within 1 year after hospital admission for acute severe ulcerative colitis. Clin Gastroenterol Hepatol 2021;19:1602-1610.
8. Papadakis KA, Tung JK, Binder SW, et al. Outcome of cytomegalovirus infections in patients with inflammatory bowel disease. Am J Gastroenterol 2001;96:2137-2142.
9. Lee HS, Park SH, Kim SH, et al. Risk factors and clinical outcomes associated with cytomegalovirus colitis in patients with acute severe ulcerative colitis. Inflamm Bowel Dis 2016;22:912-918.
10. Grossberg LB, Ezaz G, Grunwald D, Cohen J, Falchuk KR, Feuerstein JD. A national survey of the prevalence and impact of cytomegalovirus infection among hospitalized patients with ulcerative colitis. J Clin Gastroenterol 2018;52:241-245.
11. Zagórowicz E, Bugajski M, Wieszczy P, Pietrzak A, Magdziak A, Mróz A. Cytomegalovirus infection in ulcerative colitis is related to severe inflammation and a high count of cytomegalovirus-positive cells in biopsy is a risk factor for colectomy. J Crohns Colitis 2016;10:1205-1211.
12. Levin A, Yaari S, Stoff R, Caplan O, Wolf DG, Israeli E. Diagnosis of cytomegalovirus infection during exacerbation of ulcerative colitis. Digestion 2017;96:142-148.
13. Yoshino T, Nakase H, Ueno S, et al. Usefulness of quantitative real-time PCR assay for early detection of cytomegalovirus infection in patients with ulcerative colitis refractory to immunosuppressive therapies. Inflamm Bowel Dis 2007;13:1516-1521.
15. Roblin X, Pillet S, Oussalah A, et al. Cytomegalovirus load in inflamed intestinal tissue is predictive of resistance to immunosuppressive therapy in ulcerative colitis. Am J Gastroenterol 2011;106:2001-2008.
16. Dignass A, Eliakim R, Magro F, et al. Second European evidence-based consensus on the diagnosis and management of ulcerative colitis part 1: definitions and diagnosis. J Crohns Colitis 2012;6:965-990.
18. Magro F, Gionchetti P, Eliakim R, et al. Third European evidence-based consensus on diagnosis and management of ulcerative colitis. part 1: definitions, diagnosis, extra-intestinal manifestations, pregnancy, cancer surveillance, surgery, and ileo-anal pouch disorders. J Crohns Colitis 2017;11:649-670.
19. Silverberg MS, Satsangi J, Ahmad T, et al. Toward an integrated clinical, molecular and serological classification of inflammatory bowel disease: report of a Working Party of the 2005 Montreal World Congress of Gastroenterology. Can J Gastroenterol 2005;19(Suppl A):5A-36A.
20. Travis SP, Schnell D, Krzeski P, et al. Reliability and initial validation of the ulcerative colitis endoscopic index of severity. Gastroenterology 2013;145:987-995.
21. Bradford RD, Cloud G, Lakeman AD, et al. Detection of cytomegalovirus (CMV) DNA by polymerase chain reaction is associated with hearing loss in newborns with symptomatic congenital CMV infection involving the central nervous system. J Infect Dis 2005;191:227-233.
23. Banerjee D, Deb R, Dar L, et al. High frequency of parasitic and viral stool pathogens in patients with active ulcerative colitis: report from a tropical country. Scand J Gastroenterol 2009;44:325-331.
24. Nakase H, Yoshino T, Ueno S, et al. Importance of early detection of cytomegalovirus infection in refractory inflammatory bowel disease. Inflamm Bowel Dis 2007;13:364.
25. Clos-Parals A, Rodríguez-Martínez P, Cañete F, et al. Prognostic value of the burden of cytomegalovirus colonic reactivation evaluated by immunohistochemical staining in patients with active ulcerative colitis. J Crohns Colitis 2019;13:385-388.
27. Kou T, Nakase H, Tamaki H, Kudo T, Nishio A, Chiba T. Cytomegalovirus infection in patients with ulcerative colitis diagnosed by quantitative real-time PCR analysis. Dig Dis Sci 2006;51:1052-1055.
28. Cohen S, Martinez-Vinson C, Aloi M, et al. Cytomegalovirus infection in pediatric severe ulcerative colitis-a multicenter study from the pediatric inflammatory bowel disease Porto group of the European society of pediatric gastroenterology, hepatology and nutrition. Pediatr Infect Dis J 2018;37:197-201.
29. Criscuoli V, Rizzuto MR, Gallo E, Orlando A, Cottone M. Toxic megacolon and human cytomegalovirus in a series of severe ulcerative colitis patients. J Clin Virol 2015;66:103-106.