Prevalence of Epstein-Barr Virus in Patients with Inflammatory Bowel Disease

Abstract

Purpose: Inflammatory bowel disease (IBD) (Crohn's Disease and Ulcerative Colitis) is characterized by chronic inflammation of the gastrointestinal tract. IBD is often treated with steroids, mesalamines, immunomodulators and biologics. With the increasing use of immunomodulators and biologics, concerns have been raised regarding the risk of development of lymphoma in IBD patients. The incidence of lymphomas in IBD is controversial. Studies from tertiary care centers seem to associate lymphomas with IBD. Epstein-Barr Virus (EBV), a herpes virus, has been associated with lymphomas in post-transplant and immunosuppressed patients. One major barrier to understanding etiology of this increased risk is delineating between disease activity, treatment and the possible role of oncogenic viruses. Our aim is to determine the prevalence of EBV in patients who are currently being followed in our IBD clinic compared to a selected group of controls. Methods: 79 patients with IBD and 25 control subjects were studied. DNA was extracted from peripheral blood mononuclear cells (PBMC) of patients with IBD and from healthy IBD negative controls. Cell numbers were calculated using a CCR5 standard curve. EBV loads per million PBMC were determined using a real-time PCR assay. Results: A higher incidence of EBV DNA was observed in the IBD positive group compared to the IBD negative group. EBV was detected in 49% of IBD patients and in 32% of controls. Results indicate higher average levels of EBV DNA in IBD positive patients (1.29*108 compared to 1.76*103 copies/million PBMC). Conclusion: The prevalence of EBV is higher in patients with IBD than that of controls. EBV viral load averaged 5 logs greater than that of controls. Contributing factors to these findings may include immunosuppressive medications, biologics and the severity of disease activity. Due to our smaller control sample size, the difference in EBV detection was not statistically significant (P= 0.13). The significance of higher prevalence of EBV and higher EBV viral load will need to be determined in a prospective matter.