The American Gastroenterological Association (AGA) has released a new Clinical Practice Guideline that emphasizes the important role of fecal and blood biomarkers in managing Crohn’s disease. This guideline offers the most specific evidence-based recommendations to date for the use of fecal calprotectin (FCP) and serum C-reactive protein (CRP) in assessing disease activity.
Key points from the guideline include:
Role of Biomarkers: The guideline affirms that the use of biomarkers in inflammatory bowel disease (IBD) care and monitoring is no longer experimental but should be an integral part. Biomarkers provide significant benefits over relying solely on symptoms for assessing a patient’s status.
Recommendations for Asymptomatic Patients: For patients without symptoms, it is recommended to check CRP and FCP every 6-12 months. If these biomarkers are normal and the patient has had endoscopically confirmed remission within the last three years without any changes in symptoms or treatment, endoscopy can be avoided, and monitoring can continue with biomarker and clinical checks alone.
Mildly Symptomatic Patients: In this group, the role of biomarker testing may be limited due to higher rates of false positives and negatives. Endoscopic or radiologic assessment may be required to assess active inflammation.
Severely Symptomatic Patients: Elevated CRP or FCP levels can guide treatment adjustment without endoscopic confirmation in certain situations. However, normal levels might be false negatives and should be confirmed by endoscopic assessment.
Post-Surgical Remission: For patients in surgically induced remission, FCP levels below 50 mcg/g can replace routine endoscopic assessment within the first year after surgery. Higher FCP levels should prompt endoscopic assessment. However, in patients with a high risk of recurrence, biomarkers should not be relied upon, and endoscopic assessment is recommended.
The recommendations are based on low to moderate certainty evidence from randomized clinical trials and observational studies. The guideline also notes the lack of quality evidence for a third proprietary biomarker, the endoscopic healing index (EHI).
These guidelines, fully funded by the AGA Institute, align with recent AGA guidelines on ulcerative colitis, supporting the strong role of fecal and blood biomarkers in avoiding unnecessary endoscopic assessments. However, due to the weaker correlation between symptoms and endoscopic activity in Crohn’s disease, biomarker performance is optimal only in asymptomatic individuals with recently confirmed endoscopic remission.