Human Cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) are endowed with the ability of establishing lifelong latency in human hosts and reactivating in immunocompromised subjects, including patients suffering from ulcerative colitis (UC). We, therefore, aimed to investigate virus-specific immunity in UC patients. A cohort of 24 UC patients (14 responders and 10 refractory to therapy) and 26 control subjects was prospectively enrolled to undergo virus-specific serology (by ELISA assay) and assessment of both CD4+ and CD8+ virus-specific T-cell response (by interferon-γ enzyme-linked immunospotanalysis). In parallel, mucosal viral load was determined by quantitative real-time PCR and the values were correlated with both clinical and endoscopic indexes of activity. For statistics, the t-test, Mann-Withney test, Fisher's exact test and Spearman rank correlation test were applied; p < 0.05 was considered significant. EBV-specific CD4+ and CD8+ T-cell responses were significantly lower in UC patients compared to controls (p < 0.0001 and p = 0.0006, respectively), whereas no difference was found for HCMV-specific T-cell response. When dividing the UC group according to response to therapy, both responders and refractory UC patients showed a deficient EBV-specific CD4+ T-cell response with respect to controls (p < 0.04 and p = 0.0003, respectively). Moreover, both EBV and HCMV mucosal loads were significantly higher in refractory UC than in responders and controls (p = 0.007 and 0.003; and p = 0.02 and 0.001, respectively), and correlated with activity indexes. Steroid therapy seemed the main risk factor for triggering EBV colitis. Finally, no cases of IgM positivity were found in the study population. An impaired EBV-specific immunity was clearly evident in UC patients, mostly in those refractory to therapy. The ELISPOT assay may serve as new tool for quantifying and monitoring virus-specific T-cell immunity in UC.

• Klíčová slova
• Adaptive immunity, Epstein-Barr virus, Human Cytomegalovirus, Therapy, Ulcerative colitis,
• MeSH
• CD4-pozitivní T-lymfocyty metabolismus   MeSH
• CD8-pozitivní T-lymfocyty metabolismus   MeSH
• cytomegalovirové infekce farmakoterapie   imunologie   MeSH
• Cytomegalovirus imunologie   fyziologie   MeSH
• DNA virů genetika   MeSH
• infekce virem Epsteina-Barrové farmakoterapie   imunologie   MeSH
• lidé MeSH
• prospektivní studie MeSH
• steroidy škodlivé účinky   terapeutické užití   MeSH
• studie případů a kontrol MeSH
• ulcerózní kolitida farmakoterapie   imunologie   virologie   MeSH
• virová nálož MeSH
• virus Epsteinův-Barrové imunologie   fyziologie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA virů MeSH
• steroidy MeSH

The role of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in the exacerbation of inflammatory bowel disease (IBD) is still uncertain. We prospectively investigated the presence of EBV and HCMV infection in both epithelial and immune cells of colonic mucosa of IBD patients, both refractory and responders to standard therapies, in comparison with patients suffering from irritable bowel syndrome who were considered as controls, by using quantitative real-time polymerase chain reaction, immunohistochemistry and in situ hybridization, in an attempt to assess viral localization, DNA load, life cycle phase and possible correlation with disease activity indexes. We obtained clear evidence of the presence of high DNA loads of both viruses in either enterocytes or immune cells of refractory IBD patients, whereas we observed low levels in the responder group and an absence of detectable copies in all cell populations of controls. Remarkably, the values of EBV and HCMV DNA in inflamed mucosa were invariably higher than in non-inflamed areas in both IBD groups, and the EBV DNA loads in the cell populations of diseased mucosa of refractory IBD patients positively correlated with the severity of mucosal damage and clinical indexes of activity. Moreover, EBV infection resulted the most prevalent either alone or in combination with HCMV, while immunohistochemistry and in situ hybridization did not allow us to distinguish between the different phases of viral life cycle. Finally, as regards treatment, these novel findings could pave the way for the use of new antiviral molecules in the treatment of this condition.

• Klíčová slova
• Enterocytes, Inflammatory bowel disease, Mucosa, Quantitative real-time PCR, Viral infection,
• MeSH
• cytomegalovirové infekce imunologie   MeSH
• Cytomegalovirus fyziologie   MeSH
• dospělí MeSH
• idiopatické střevní záněty imunologie   virologie   MeSH
• infekce virem Epsteina-Barrové imunologie   MeSH
• kolon imunologie   virologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• progrese nemoci MeSH
• prospektivní studie MeSH
• střevní sliznice imunologie   virologie   MeSH
• virus Epsteinův-Barrové fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH