The hazardous burden of Herpesviridae in inflammatory bowel disease:: The case of refractory severe ulcerative colitis

Background. Herpesviridae infection or spread may be a hazard in immunodepressed patients. In the field of inflammatory bowel disease, refractory severe ulcerative colitis is a challenging condition, closely associated to immunosuppression both for inanition due to the disease activity and for immunosuppressive treatments. Cytomegalovirus (CMV) has been proposed as a major cause of refractoriness, while other Herpesviridae may be a risk factor in the long-term follow-up. Aim of the study. To evaluate the positivity rates of CMV, Epstein-Barr (EBV) and Human herpes virus-8 (HHV8) in a consecutive group of ulcerative colitis patients who underwent colectomy for refractoriness to medical treatment compared to a control group, using state of the art methods. Patients and methods. Colonic specimens from 24 consecutive patients with ulcerative colitis submitted to colectomy for refractoriness and from 20 controls (submitted to colectomy for colorectal cancer) were studied. Standard histology and immunohistochemistry (IHC) for CMV and specific polymerase chain-reaction (PCR) for CMV, EBV and HHV8 were carried out. Results. Regarding CMV, 1 case (4%) was positive at histology and IHC, whereas 3 cases (13%) were positive at PCR, compared to none in the control group (p=0.239). For EBV 2 cases (8%) and 2 controls (10%) were positive at PCR. None of the cases or of controls was positive for HHV8. The only clinical characteristic independently associated to CMV positivity was the white blood cell count at admission, higher among CMV positive patients (p < 0.001). At the end of the post-surgery follow-up (median 7.3 years) none of the CMV positive cases experienced pouchitis, compared to 3/21 (14%) of the CMV negative cases (p=1.000). Discussion. Our data suggest that CMV is uncommon (13%), even though PCR techniques, considered to be the most sensitive tools, were used for virus detection and the study population is made by highly selected patients with definite refractoriness. EBV and HHV8 may represent a theoretical risk of immunosuppressive therapy because of their potential role as cancer triggers; however in our study, results seem to be reassuring that UC patients undergoing immunosuppressive therapy are not exposed to an excessive risk of viral infection. (c) 2006 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.