American Gastroenterological Association guidelines suggest using symptom assessment and endoscopic evaluation to monitor patients with Crohn’s disease.
“In the management of Crohn’s disease, it is now recognized that a treat-to-target strategy achieves the best outcomes,” Ashwin Ananthakrishnan, MD, MPH, notes. Conventionally, this has relied on colonoscopy assessments alone, which are limited by the procedures’ inconvenience, cost, and invasiveness. Consequently, there is growing utilization of biomarkers to help augment the information obtained from a colonoscopy.”
Biomarkers also allow for more frequent monitoring in these patients, which enables greater disease control, he continues.
“Biomarkers are increasingly used for evaluating and monitoring patients with Crohn’s disease, but there are no population-based estimates of how frequently they are obtained in the United States. The growing body of evidence on biomarkers, in particular fecal calprotectin and C-reactive protein (CRP), necessitated guidelines to inform the best strategy on the use of these monitoring tools.”
Dr. Ananthakrishnan and colleagues published the American Gastroenterological Association guidelines on using biomarkers for managing Crohn’s disease in Gastroenterology. The multidisciplinary panel used the Grading of Recommendations Assessment, Development, and Evaluation framework to develop patient-centered clinical questions and examine evidence on the performance of fecal calprotectin, serum CRP, and the Endoscopic Healing Index in patients with Crohn’s disease of varying degrees, including those who were asymptomatic, had symptoms of varying severity, or who were in surgically induced remission. They evaluated biomarker performance against the “gold standard” of endoscopic activity, defined as a Simple Endoscopic Score for Crohn’s Disease of equal to or greater than three, according to the study results.
Assessing Biomarkers & Symptoms in Combination
The guideline includes 11 conditional recommendations. They focus on several subgroups of patients with Crohn’s disease.
For patients in symptomatic remission, the panel suggests a combination strategy that monitors biomarkers and symptoms rather than symptoms only. For patients in symptomatic remission, a fecal calprotectin level of less than 150 μg/g and normal CRP rule out active inflammation, allowing patients to avoid endoscopy to assess disease activity. However, Dr. Ananthakrishnan and colleagues note that asymptomatic patients with elevated biomarkers should undergo confirmatory endoscopy before treatments are adjusted.
In patients with mild symptoms, the researchers state that “neither normal nor elevated biomarkers alone are sufficiently accurate to determine endoscopic activity.” For those with moderate to severe symptoms, elevated fecal calprotectin (>150 μg/g) or serum CRP (>5 mg/L) is indicative of endoscopic activity, and routine endoscopic assessment for disease activity is unnecessary.
Among low-risk patients with surgically induced remission who are receiving pharmacologic prophylaxis, a normal fecal calprotectin level “reliably rules out endoscopic recurrence,” the researchers wrote. The guidelines suggest using endoscopy for other postoperative patients to determine postoperative recurrence.
“In general, the guidelines suggest that a monitoring strategy that relies on a combination of symptom assessment and endoscopic evaluation performs superiorly to one using symptom-based follow-up alone,” Dr. Ananthakrishnan says. “In asymptomatic patients with Crohn’s disease, a normal fecal calprotectin can reliably rule out active inflammation. Similarly, in those with moderate to severe symptoms, elevated biomarkers can suggest underlying disease activity.”
He notes that whether these biomarkers are positive or negative, they “are less informative” in patients with mild symptoms.
For postoperative, low-risk patients, “a normal fecal calprotectin reliably can rule out early endoscopic recurrence,” Dr. Ananthakrishnan says. “In high-risk postoperative patients, the performance is not sufficient to obviate the need for an endoscopy.”
Up Next: Guidelines in Clinic & Additional Research
The key message of the guideline is two-fold, he continues, and can be used to employ the guidelines in the clinic.
“The most important takeaway is that we should follow biomarker (and symptom) assessment rather than symptom assessment alone. The second important takeaway is to interpret the biomarkers in the context of symptoms and pre-test probability of significant endoscopically active disease.”
Pointing to future research, Dr. Ananthakrishnan says: “The next steps include a more nuanced examination of biomarkers based on specific disease phenotypes, such as location; examining the utility of biomarkers in combination with other tests, such as magnetic resonance enterography or intestinal ultrasound, and using biomarkers for other goals in addition to assessing disease activity, such as prediction of treatment response and prediction of other disease complications.”
