

THURSDAY, July 30, 2026 (HealthDay News) -- Disease-specific immune trajectories are identified years before onset of inflammatory bowel disease (IBD), according to a study published online July 21 in Gut.
Arno R. Bourgonje, M.D., Ph.D., from the Icahn School of Medicine in New York City, and colleagues applied high-throughput phage-display immunoprecipitation sequencing to profile antibody responses in 2,000 longitudinal serum samples from 200 individuals who developed Crohn disease (CD), 200 who developed ulcerative colitis (UC), and 100 matched healthy controls; samples were collected up to 10 years before diagnosis.
The researchers found that in pre-CD and pre-UC individuals, antibody repertoire variability was increased up to about four years prediagnosis. Elevated herpesvirus-directed responses (notably Epstein-Barr virus) and anti-flagellin antibodies were revealed in differential analyses up to 10 years prediagnosis in CD, especially in those who later developed complicated or ileal disease. Toward diagnosis, responses to encapsulated bacteria (e.g., Streptococcus pneumoniae, Haemophilus, Neisseria) declined progressively. Combined antimicrobial, antiviral, and autoantibody signatures, including antibodies against the MAP kinase-activating death domain protein, characterized pre-UC.
"For years, we've known that inflammatory bowel disease has a long silent phase before symptoms emerge, but we have had limited insight into what is happening during that period," coauthor Jean-Frederic Colombel, M.D., also from the Icahn School of Medicine, said in a statement. "This work provides one of the clearest pictures yet of the immune changes that precede IBD and moves the field closer to earlier diagnosis and, ultimately, disease prevention."
Several authors disclosed ties to the biopharmaceutical industry.