Cytomegalovirus and Inflammatory Bowel Diseases (IBD) with a Special Focus on the Link with Ulcerative Colitis (UC)

Abstract

Cytomegalovirus (CMV) infects approximately 40% of adults in France and persists lifelong as a latent agent in different organs, including gut. A close relationship is observed between inflammation that favors viral expression and viral replication that exacerbates inflammation. In this context, CMV colitis may impact the prognosis of patients suffering from inflammatory bowel diseases (IBDs), and notably those with ulcerative colitis (UC). In UC, the mucosal inflammation and T helper cell (TH) 2 cytokines, together with immunomodulatory drugs used for controlling flare-ups, favor viral reactivation within the gut, which, in turn, increases mucosal inflammation, impairs corticoid and immunosuppressor efficacy (the probability of steroid resistance is multiplied by more than 20 in the case of CMV colitis), and enhances the risk for colectomy. This review emphasizes the virological tools that are recommended for exploring CMV colitis during inflammatory bowel diseases (IBD) and underlines the interest of using ganciclovir for treating flare-ups associated to CMV colitis in UC patients.

Therapeutic Mechanism and Effect of Camptothecin on Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice

“…UC is a chronic inflammatory disease whose main effects are concentrated in the colon. The incidence of UC is increasing globally [ 16 ]. Modern medical treatment is usually combined with drugs such as salicylates, glucocorticoids, and immunosuppressants.…”

Human Cytomegalovirus and Autoimmune Diseases: Where Are We?

“…Activation of IFN-γ-releasing T helper cells (Th1/Th17) and CTL is a common marker of CD, thought to counteract HCMV activity. Conversely, UC is characterized by a Th2/Th9 profile that does not inhibit HCMV replication [ 217 , 218 ]. These key immunological differences may offer some clues as to why HCMV reactivation is an infrequent event during CD flares, whereas it is recurrent in patients affected by UC.…”

The Impact of Human Herpesviruses in Clinical Practice of Inflammatory Bowel Disease in the Era of COVID-19

“…CMV colitis, which occurs most commonly in the gastrointestinal tract, can develop in patients with IBD, especially in UC, and this is associated with a significant clinical morbidity, such as a toxic megacolon, requirement of colectomy, and high mortality rate [ 48 , 49 ]. Regarding risk factors for CMV colitis in UC, these include: higher age, higher activity of mucosal inflammation, and use of immunosuppressive treatment, including corticosteroids and thiopurines, but not TNF-α inhibitors [ 7 ].…”

“…The human herpesviruses (HHVs) are divided to three categories, based on biological characteristics: α-herpesviruses (which include herpes simplex virus (HSV) types 1 (HSV-1) and 2 (HSV-2), varicella-zoster virus (VZV)), β-herpesviruses (which include cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), and human herpesvirus 7 (HHV-7)), and γ-herpesviruses (which include Epstein-Barr virus (EBV) and human herpesvirus 8 (HHV-8)) [ 6 ]. The complication of CMV enteritis in IBD, especially in UC practice, is believed to be caused by CMV reactivation as a result of disruption of intestinal barrier function, inflammation, or strong immunosuppressive therapy, and is known to affect the prognosis of UC [ 7 ]. However, the relationship between other HHVs and IBD remains unclear.…”