A study led by Dr Arno Bourgonje at the University Medical Centre Groningen in the Netherlands and the Icahn School of Medicine at Mount Sinai in New York analysed blood samples from 500 US military personnel, 200 of whom later developed Crohn's disease and 200 who developed ulcerative colitis. By screening for antibodies against hundreds of thousands of protein fragments from bacteria, viruses, food and human tissues, the researchers found distinct antibody patterns that predated diagnosis by up to a decade.
For those who later developed Crohn's disease, the blood showed elevated antibodies against the Epstein-Barr virus, which causes glandular fever. The signal was strongest in individuals who later experienced more severe complications. In people who developed ulcerative colitis, a different pattern emerged, including antibodies targeting one of the body's own proteins.
The findings, published in the journal Gut and presented at the United European Gastroenterology meeting in Barcelona, are a step toward catching IBD early. Currently, the two main forms of IBD are typically treated only after symptoms have already caused damage to the gut. At least 3.8 million people worldwide live with the condition.
“For too long we have only been able to treat inflammatory bowel disease once the damage is done, and for many people that is too late,” said Bourgonje. “What we have shown is that the disease begins years before symptoms appear, and the immune system leaves warning signs long before diagnosis. This is not yet a test that can tell someone they will become ill, but it is an important step towards catching the disease earlier and, one day, preventing it.”
Professor James Lindsay of Barts Health, who was not involved in the research, said the study provided “important insights into the causes of Crohn’s disease and ulcerative colitis, potentially adding new tools to help identify those at risk of IBD.” But he cautioned that the techniques were “very much a research tool” and not yet ready for the clinic.
Marianne Radcliffe, chief executive of the patient charity Crohn’s & Colitis UK, said: “For people affected by Crohn’s and colitis, research like this is an important step forward. Every new insight helps build a clearer understanding of how these conditions develop, including the changes that may occur years before symptoms appear.”
Bourgonje and colleagues hope IBD could follow the path of type 1 diabetes, where a blood test can identify early immune attack on the pancreas, allowing treatment that delays onset. The results need confirmation in other populations and establish a link rather than proving the infections cause IBD, but they open the door to earlier intervention and potentially preventive strategies.