Simple blood test can detect debilitating bowel disease years before any symptoms develop
A simple blood test can predict who will suffer from a debilitating bowel disease later in life, paving the way for early diagnosis and even prevention, scientists say.
Researchers from Mount Sinai Hospital’s centre for Inflammatory Bowel Disease (IBD) in New York, took samples from more than 380 people deemed at high-risk of developing Crohn’s Disease (CD).
Crohn’s disease is a chronic inflammatory gut condition which occurs when the immune system mistakenly attacks healthy tissue in the gut and other parts of the body, causing abdominal pain, diarrhoea, and blood or mucus in the stool.
Other common symptoms include extreme fatigue, general malaise, loss of appetite, unexplained weight loss and, in children, delayed puberty.
Using computer imaging to look at participants’ response to a protein found on gut bacteria, called flagellin, they found that more than a third of participants had elevated antibody responses linked with the disease.
Dr Ken Croitoru, a gastroenterologist and study lead-author, explained: ‘We wanted to know: do people who are at risk of developing the disease, who are healthy now, have these antibodies against flagellin.
‘We looked, we measured, and yes indeed, some of them did.’
The study, published in the journal Clinical Gastroenterology and Hepatology, highlights the interplay between bacteria in the gut and immune system responses as a crucial step in developing the condition.
About half-a-million Britons suffer with Crohn’s disease, which causes agonising pain, diarrhoea, exhaustion and extreme weight loss (Stock image)
Previously, as part of a wider project, called the Genetic Environmental and Microbial Project, the team discovered that long before symptoms appear, an inflammatory immune response targeting gut bacteria often occurs in Crohn’s patients.
In healthy individuals, bacteria coexist in the gut – to make up the gut microbiome – and play an essential role in maintaining digestive health.
However, in Crohn’s disease sufferers, the immune system attacks these healthy, beneficial microbes, resulting in elevated levels of antibodies targeting various gut proteins such as flagellin.
It’s not yet fully understood why this happens, although it’s thought to be partly genetic, which is why the researchers specifically studied first-degree relatives of people with the disease.
Researchers followed 381 first-degree relatives of Crohn’s patients, 77 of whom went on to develop the disease around two-and-a-half-years later.
Among them, 28 had elevated antibody responses, suggesting that this immune reaction may contribute to triggering the onset of the disease, rather than simply being a consequence of it.
Interestingly, immune responses were strongest in siblings, highlighting the role of shared environmental exposure, as well as genetics.
Dr Sun-Ho Lee, another gastroenterologist and study co-author, said: ‘ Our findings raise the potential for designing a flagellin-directed vaccine in selected high-risk individuals for prevention of disease.’
The once-a-month injection, guselkumab, is used to treat Crohn’s disease and ulcerative colitis , two debilitating conditions caused by the immune system mistakenly attacking healthy tissue in the gut and other areas of the body. Pictured: Stock image
The team are now looking to validate their results through further studies.
About half-a-million people in the UK suffer with the debilitating condition which can also trigger pain in the joints, anus and eyes.
About a third of patients living with the condition, where the gut lining becomes inflamed, will require surgery.
Currently, the condition is managed by drugs called biologics – injections which limit the damage caused by the immune system to the body. However, not all patients respond to them.
The NHS spending watchdog, the National Institute for Health and Care Excellence (NICE) is currently reviewing a new drug called guselkumab which has been shown to eliminate symptoms within three months.
The once-a-month jab binds to immune cells that cause this damage, significantly reducing symptoms.
Studies show that more than half of patients with Crohn’s – an aggressive condition which can damage the gut as well as the mouth, stomach, and anus – were symptom-free within 12 weeks of starting guselkumab.
Experts say the £2,250-a-month jab will be a lifeline and crucial addition to the Health Service’s bowel disease treatments.
