Prospective Risk Evaluation and Detection of Crohn's Disease in First-degree Relatives

The PREDICT-CD study aims to validate a risk score for the development of Crohn's disease, based on serological biomarkers and lifestyle-related factors. Given that having a family member with the disease is the strongest known risk factor, the target population will consist of first-degree relatives (aged 16 to 35) of individuals diagnosed with Crohn's disease. This study will be conducted within Work Package 3 (WP3) of the INTERCEPT project, a consortium funded by the Innovative Health Initiative (IHI). The research will take place across 28 centres in seven countries: Portugal, Spain, France, Italy, the Netherlands, Sweden, and Poland. To achieve the study objectives, individuals with Crohn's disease (referred to as patients) will be invited to participate and to engage their eligible first-degree relatives. At the baseline visit, the patient's physician will complete a clinical questionnaire covering disease history, treatments, and previous interventions. At the same time, first-degree relatives (parents, siblings, or children) will donate a blood sample for serum isolation and, optionally, a whole blood and stool sample. They will also complete a questionnaire regarding their health status, habits, and preferences. Follow-up questionnaires will be administered every six months to monitor the onset of symptoms or behavioural changes.

Inclusion Criteria: * Male or female participants, between 16 and 35 years old * FDR (parent, full-siblings or offspring) from a patient with an established diagnosis of CD * Participants able to understand the information provided to them and to give written informed assent or consent for the study. Exclusion Criteria: * Prior diagnosis of IBD * Any legal or medical condition that limits the information and participation in the study * Inability to verify CD diagnosis in the proband * Participants unwilling or unable to provide informed written consent * Participants unwilling or unable to donate blood for serum