Inflammatory bowel disease warning signs: blood antibodies may flag IBD a decade early
Inflammatory bowel disease warning signs in the blood - patterns of antibodies - could predict IBD up to a decade before diagnosis, researchers say, after testing samples from 500 US military personnel.
Inflammatory bowel disease warning signs: blood antibodies may flag IBD a decade early
Inflammatory bowel disease warning signs circulating in the blood may reveal IBD years before anyone falls ill, according to a study of blood samples from US military personnel. Researchers report that immune signals linked to Crohn's disease were detectable a full decade before diagnosis, raising the possibility of identifying and treating the condition before the gut is damaged.
Crohn's disease and ulcerative colitis, the two main forms of IBD, are typically treated only after symptoms appear, when the gut has already been damaged. At least 3.8 million people worldwide live with the condition, an immune disorder that drives chronic inflammation of the digestive tract and causes pain, diarrhoea and fatigue.
How the study worked
Dr Arno Bourgonje, who works at the University Medical Centre Groningen in the Netherlands and the Icahn School of Medicine at Mount Sinai in New York, led the work with colleagues at Mount Sinai and the Medical University of Vienna. The team examined 2,000 blood samples from 500 people: 200 who later developed Crohn's disease, 200 who developed ulcerative colitis and 100 who developed neither.
Each sample was screened for antibodies that the immune system might have produced in response to hundreds of thousands of fragments of proteins drawn from bacteria, viruses, food and the body's own tissues. The findings were published in the journal Gut and presented at the United European Gastroenterology meeting in Barcelona.
Different patterns for Crohn's and colitis
The two conditions left different fingerprints in the blood. In people who later developed Crohn's disease, antibodies against Epstein-Barr virus, which causes glandular fever, were more common, and the differences were already visible a decade before diagnosis.
- The Epstein-Barr virus signal was strongest in those who later developed more severe, complicated Crohn's disease, which can narrow the bowel or create abnormal channels
- People who developed ulcerative colitis showed a different pattern, including antibodies against one of the body's own proteins
Why earlier detection matters
Treatment currently relies on anti-inflammatory and immune-suppressing drugs, but many patients do not respond, many undergo surgery to remove damaged sections of bowel, and longstanding inflammation raises the risk of bowel cancer. Bourgonje said that for too long doctors have only been able to treat the disease once the damage is done, and for many people that is too late.
"What we have shown is that the disease begins years before symptoms appear, and the immune system leaves warning signs long before diagnosis."
Bourgonje stressed this is not yet a test that can tell someone they will become ill, but an important step towards catching the disease earlier and possibly preventing it. The exact cause of IBD is unknown, though a misfiring immune system, genetics and gut microbes can all contribute.
Caution and next steps
Researchers say the results need to be confirmed in other groups of people, and that they show a link rather than proving the infections cause IBD. James Lindsay, professor of gastroenterology at Barts Health, who was not involved in the research, said it offered important insights into the causes of Crohn's disease and ulcerative colitis, potentially adding new tools to help identify those at risk of IBD. He cautioned that the techniques remain very much a research tool and are not yet ready for the clinic.
The longer-term hope is that IBD could eventually follow the path of type 1 diabetes, where a blood test can identify people whose immune systems have begun attacking the pancreas before symptoms, allowing treatment that delays onset.
Marianne Radcliffe, chief executive of Crohn's & Colitis UK, welcomed the work: "For people affected by Crohn's and colitis, research like this is an important step forward."
She added that every new insight helps build a clearer understanding of how these conditions develop, including changes that may occur years before symptoms appear.
