P276 Reactivation of Epstein–Barr virus and cytomegalovirus behaves differently in pathophysiology of ulcerative colitis

Abstract

Abstract Background Cytomegalovirus (CMV) and Epstein–Barr virus (EBV) are members of the herpesvirus family. CMV reactivation is often complicated with ulcerative colitis (UC) and is known as one of exacerbation factors. However, the association between EBV reactivation and pathophysiology of UC is still unclear. Methods This study enrolled 116 active UC patients who received colonoscopy between January 2005 and January 2019 in Kyoto University Hospital. 244 biopsy specimens were obtained from inflamed colonic mucosa to assess EVB and CMV reactivation. Viral loads of EBV and CMV in inflamed mucosa were measured by real-time PCR assay. The reactivation of those viruses was defined as DNA quantity more than 10 copies/μg DNA. Clinical severity was assessed by Lichtiger index and defined as follow: 4–8 as mild, 9–12 as moderate, and more than 12 as severe. Endoscopic severity was assessed by Mayo endoscopic score. We examined the correlation between the positivity of each viral reactivation and patients’ characteristics or prognosis of UC. Results (1) Median age, Lichtiger score and Mayo endoscopic score at the time to assess the viral reactivations were 36 years-old, 8, and 3, respectively. (2) EBV and CMV reactivation were observed in 127 samples (52.0%) and 73 samples (29.9%), respectively. There was no correlation between EBV and CMV viral load (correlation coefficient 0.19), although a significant correlation between those viral reactivations was observed in active colonic mucosa of UC patients (p = 0.002). (3) The proportion of EBV reactivation was higher in both clinically and endoscopically severe UC patients compared with those with mild activity. On the other hands, there was no association between CMV reactivation and clinical or endoscopic severity. (4) Multivariate analysis indicated risk factors for EBV reactivation as receiving anti-TNF-α antibodies (odds ratio [OR] 4.2) or calcineurin inhibitors (OR 3.5), and CMV reactivation (OR 2.1), respectively. (5) Multivariate analysis also indicated risks for CMV reactivation as steroid-refractory (OR 4.7) and EBV reactivation (OR 2.0). (6) EBV and CMV reactivation did not affect clinical outcomes including the requirement of colectomy or intensification of immunosuppressive treatments and the incidence of colitis-associated cancer, dysplasia and lymphoproliferative disease. Conclusion Reactivation of EBV or CMV may behave differently in pathophysiology of UC. Further studies are required to clarify the role of EBV reactivation on colonic inflammation in UC patients.