Response to medical treatment in patients with Crohn's disease: The role of NOD2/CRAD15, disease phenotype, and age of diagnosis

Purpose: Factors influencing response to medications in Crohn's disease (CD) patients are not fully understood. We aimed to evaluate the relationships between NOD2/CARD15 mutations, disease phenotype and age of CD diagnosis and response to medical treatment with systemic steroids, azathioprine (AZA) or 6-mercaptopurine (6-MP), and infliximab. Methods: A retrospective medical records analysis was made of patients previously tested for the CD-associated NOD2/CARD15 mutations. Harvey- Bradshaw score was used to assess remission or response to therapy. Results: CD-associated NOD2/CARD15 mutations were not related to the rate of steroids dependency or clinical response to AZA/6-MP and infliximab. Steroid dependency was associated with colonic involvement. Thirty-three of 127 (26%) patients with colonic disease were steroid dependent, compared with 7/72 (9.7%) patients with isolated small bowel disease (ISBD), (p = 0.009). ISBD was mildly associated with a better remission/response to AZA/6-MP treatment. Disease behavior and age of diagnosis were not related to response to therapy. Conclusions: Response to treatment with systemic steroids, AZA/6-MP and infliximab are not related to NOD2/CARD15 mutations, age of diagnosis and disease behavior. Patients with colonic disease have higher rates of steroid dependency.