Crohn’s disease can be detected years before symptoms appear

The analysis is based on identifying the immune response to flagellin, a protein present in a number of intestinal bacteria. Some people experience abnormally high levels of this response long before the clinical onset of Crohn’s disease, a research team from the Lunenfeld-Tanenbaum Research Institute at Sinai Hospital has shown. The study results, published in the journal Clinical Gastroenterology and Hepatology, highlight that interactions between the gut microbiota and the immune system may play a critical role in the earliest stages of Crohn’s disease.

According to the scientists, the detection of antibodies to flagellin many years before the onset of clinical signs indicates that this immune response may be involved in the initiation of Crohn’s disease, rather than arising as a consequence of the disease. Studying such early changes can lead to the development of more accurate prediction methods, as well as new approaches to prevention and therapy.

The study included 381 first-degree relatives of people with Crohn’s disease. During observations, the disease developed in 77 participants. Of this group, 28 people had elevated levels of antibodies, that is, more than a third of the sick. The strongest immune response was seen in siblings, suggesting a significant role for shared environmental factors—a finding consistent with earlier work by Dr. Croitoru’s team. In addition, the scientists found that an early immune response to flagellin from bacteria of the Lachnospiraceae family was associated with inflammatory processes in the intestines and disruption of the barrier function of the intestinal wall – typical signs of Crohn’s disease. On average, diagnosis was made almost two and a half years after blood samples were collected.