Cytomegalovirus Infection in Steroid-refractory Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory disorder of the colonic mucosa characterized by recurrent attacks of bloody diarrhea, abdominal cramping and mucosal ulceration that often requires long-term therapy to maintain remission (Fefferman and Farrell 2005). In addition, refractory UC is moderate to severe colitis refractory or intolerant to conventional therapy (steroid-refractory colitis) or immunomodulators (immunomodulator-refractory colitis) that may end at colectomy( Baumgart and Sandborn 2007)(Garud andPeppercorn 2009).

The etiology of UC is unknown; however, genetic and environmental factors and microorganisms may play an important role. Epidemiological and microbiologic studies suggest that enteropathogenic microorganisms play a substantial role in the clinical initiation and relapses of IBD(Johnson. 2012) (Goodman et al. 2015). e.g. active UC has been associated with increased detection rates of Clostridium difficile, cytomegalovirus (CMV).

Cytomegalovirus (CMV) is a double-stranded DNA virus of the Herpesviridae family. After primary infection, the virus is known to maintain a persistent, life-long infection often as a latent form that can be found in several organs or tissues especially in the colon .

Cytomegalovirus infection (CMV) has been described in patients with inflammatory bowel disease (IBD) as a cause of relapse, mainly in those with steroid refractory disease .This infection is also responsible for a more severe clinical course and it may cause death if not treated early Moreover, an improvement of clinical status when antiviral therapy was initiated, suggesting an active role of CMV (Shukla et al. 2015) .

The prevalence of CMV infection in IBD patients is unclear depending on the method of diagnosis used. It was ranged 16 - 34% in patients with moderate-to-severe UC was using serological and histological tests(Kishore et al 2004) (Wada et al. 2003) .