Blood antibodies predict bowel disease a decade before diagnosis

Antibody patterns in ordinary blood samples can mark people who will develop inflammatory bowel disease up to ten years before diagnosis, according to research published in the journal Gut and presented at the United European Gastroenterology meeting in Barcelona. Arno Bourgonje of the University Medical Centre Groningen and the Icahn School of Medicine at Mount Sinai, with colleagues at the Medical University of Vienna, screened 2,000 blood samples from 500 US military personnel: 200 who later developed Crohn's disease, 200 who developed ulcerative colitis and 100 who developed neither.

The samples were tested for antibodies against hundreds of thousands of protein fragments from bacteria, viruses, food and the body's own tissues. Future Crohn's patients carried more antibodies against Epstein-Barr virus, the cause of glandular fever; future colitis patients showed a different signature, including antibodies against one of the body's own proteins. The differences were visible a decade before diagnosis, and strongest in those destined for the severe complications that narrow the bowel or create abnormal channels through it.

Both diseases are treated only once symptoms appear, when the gut is already damaged. Anti-inflammatory and immune-suppressing drugs fail a large share of the at least 3.8 million people worldwide living with IBD, a significant number have sections of bowel surgically removed, and longstanding inflammation raises the risk of bowel cancer. "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," Bourgonje said.

The finding is a link, not a proven cause, and needs confirmation in other populations. Bourgonje's own framing is cautious — this is not yet a test that can tell someone they will become ill. The comparison the researchers reach for is type 1 diabetes, where blood tests now catch the immune system attacking the pancreas before symptoms appear and treatment can delay onset. That path works because something can be offered to the people identified.

That is the gap the field now occupies. Britain's Rosalind Franklin Institute recently installed the country's only super-resolution microscope for inflammatory bowel disease, resolving structures down to 20 nanometres in living cells. Research can now see the damage in finer detail than ever and, on this evidence, see it coming years in advance. What does not exist is the clinic in between: a queue for patients who feel fine, a budget line for monitoring people who are not yet sick, or a treatment to offer them when the antibodies appear.

The soldiers gave their blood while healthy. The disease was already legible in it, and would stay untreated for another decade.