A new genetic marker, HLA-DRB1*01:03, has been linked to more severe forms of Crohn’s disease and ulcerative colitis, according to researchers at the Wellcome Sanger Institute. The marker was identified in around one in twenty people with inflammatory bowel disease (IBD) after analysis of samples from more than 43,000 patients, raising the prospect of earlier, more targeted treatment for those most at risk of aggressive disease.
Background
IBD, which includes Crohn’s disease and ulcerative colitis, follows a highly variable course. Some patients experience mild, intermittent symptoms, while others progress to severe inflammation, hospitalisation, or surgery within a few years of diagnosis. Current treatment largely follows a step-up model, in which milder therapies are tried first and stronger drugs are introduced only if the disease fails to respond. This approach can mean that patients destined for a more aggressive disease course are not identified until after complications have already developed. Genetic research has increasingly focused on finding markers that could help clinicians distinguish, at or near diagnosis, which patients are likely to need earlier, more intensive intervention.
Key Findings
Researchers at the Wellcome Sanger Institute report that a specific genetic variant combination, HLA-DRB1*01:03, is associated with more severe disease in both Crohn’s disease and ulcerative colitis. The finding comes from analysis of samples drawn from a large cohort of more than 43,000 patients with IBD, making it one of the larger genetic studies in this area to date. The marker was present in approximately one in twenty of the patients studied, suggesting a meaningful minority of the IBD population could be identified through genetic testing. According to the research team, carriers of this marker were more likely to experience severe disease outcomes, which the researchers suggest could include a greater likelihood of needing escalated therapy or surgery. The study authors note that this discovery does not offer a cure or a way to prevent IBD, but it does provide a potential tool for risk stratification. Identifying carriers early could, in principle, allow clinicians to monitor these patients more closely from diagnosis and consider earlier use of advanced therapies, rather than waiting for signs of disease progression under a traditional step-up approach.
Clinical Relevance
For gastroenterologists and IBD nurses, a validated genetic marker of this kind could eventually support decisions about how closely to monitor a newly diagnosed patient and when to consider advanced therapy rather than conventional first-line treatment. For patients, earlier identification of high-risk disease could translate into closer follow-up and a reduced likelihood of reaching a point where hospitalisation or surgery becomes necessary. The researchers are clear that this remains a risk-stratification tool rather than a diagnostic or curative test, and further validation would be expected before it could inform routine clinical decision-making. Nonetheless, the findings add to a growing evidence base supporting more individualised approaches to IBD care.
Reference
Wellcome Sanger Institute. Genetic marker HLA-DRB1*01:03 linked to severe inflammatory bowel disease. Cambridge: Wellcome Sanger Institute; 2024.
This article is a journalistic summary for informational purposes only. It does not constitute clinical advice or a recommendation to alter treatment decisions.