Epstein–Barr virus infection increases the risk for inflammatory bowel disease

Background Previous studies have suggested that infection with Epstein–Barr virus (EBV) plays a role in the etiology of Hodgkin lymphoma, multiple sclerosis, systemic lupus erythematosus (SLE), Crohn’s disease, and ulcerative colitis. We investigated whether a history of infectious mononucleosis, a well-known marker of early EBV exposure, is also associated with these diagnoses. Methods In case-control studies, we examined the concurrence of infectious mononucleosis, Hodgkin lymphoma, multiple sclerosis, SLE, Crohn’s disease, and ulcerative colitis in the same patients, using the University of Pennsylvania Health System (UPHS) electronic database. Patients diagnosed with infectious mononucleosis, Hodgkin lymphoma, multiple sclerosis, Crohn’s disease, or ulcerative colitis were identified by their corresponding International Classification of Diseases, 10 th Revision. We compared the observed concurrence of each two diagnoses with their expected frequencies in the overall UPHS population by calculating odds ratios and their corresponding 95% confidence intervals. Results The UPHS database from 2000 to 2024 contained a total of 3 955 827 unique patients. Among these individuals, 10 462 were diagnosed with infectious mononucleosis, 5552 with Hodgkin lymphoma, 16 777 with multiple sclerosis, 18 475 with Crohn’s disease, and 22 830 with ulcerative colitis. A prior history of infectious mononucleosis carried a 1.8–7.1-fold increased risk for concurrent Hodgkin lymphoma, multiple sclerosis, SLE, Crohn’s disease, or ulcerative colitis. Moreover, anyone of the five diagnoses Hodgkin lymphoma, multiple sclerosis, SLE, Crohn’s disease, ulcerative colitis was significantly associated with the concurrence of any other diagnosis from the same group. Conclusion The six diagnoses, infectious mononucleosis, Hodgkin lymphoma, multiple sclerosis, SLE, Crohn’s disease, and ulcerative colitis tended to cluster in the same patient population. These results support the hypothesis that these diagnoses share a common etiology, most likely related to EBV infection during early lifetime.