At what frequency should we repeat the calprotectin (fecal calprotectin) test?

Frequency of Fecal Calprotectin Testing in Inflammatory Bowel Disease

Fecal calprotectin should be repeated every 6-12 months in patients with inflammatory bowel disease (IBD) who are in symptomatic remission, and every 2-4 months in patients being treated for active symptoms. 1

Monitoring Recommendations Based on Clinical Status

Patients in Symptomatic Remission:

• Interval biomarker monitoring should be performed every 6-12 months in patients in symptomatic remission 1
• Biomarker-based monitoring is particularly useful in patients whose biomarkers have historically correlated with endoscopic disease activity 1
• In patients with elevated biomarkers but sustained symptomatic remission, repeat measurement of biomarkers in 3-6 months may be a reasonable alternative to endoscopic assessment 1
• If biomarkers remain elevated on repeat evaluation, then endoscopic assessment is warranted 1

Patients with Active Symptoms:

• Interval biomarker assessment and treatment adjustment should be performed every 2-4 months in patients being treated for active symptoms 1
• After resolution of symptoms and normalization of biomarkers, endoscopic evaluation should be performed to rule out active inflammation, typically 6-12 months after treatment initiation or adjustment 1

Interpretation of Calprotectin Results

Key Cutoff Values:

• Fecal calprotectin <150 μg/g suggests minimal inflammation and can rule out active inflammation in patients in symptomatic remission 1
• Fecal calprotectin >150 μg/g suggests possible active inflammation and may warrant further evaluation 1
• In patients who have recently achieved symptomatic remission after treatment adjustment in the preceding 1-3 months, a lower cutoff of <50 μg/g may be preferred to detect endoscopic improvement 1

Predictive Value of Results:

• Fecal calprotectin levels <130 μg/g are consistently associated with maintained disease remission 2
• Concentrations >300 μg/g allow predicting relapse with high probability within the following 4 months 2
• The predictive value of calprotectin is stronger in ulcerative colitis than in Crohn's disease 3

Special Considerations

Repeat Testing After Initial Elevation:

• In patients with elevated calprotectin but no symptoms, repeat testing in 3-6 months is reasonable before proceeding to endoscopy 1
• Lack of normalization or persistently elevated biomarkers in patients whose symptoms recently resolved after initial treatment likely suggests active inflammation and may warrant treatment adjustment without need for endoscopic evaluation 1

Disease-Specific Considerations:

• The predictive value of calprotectin differs between ulcerative colitis and Crohn's disease, with a stronger predictive value in ulcerative colitis 3
• For patients with predominantly small bowel Crohn's disease, radiologic assessment may be a reasonable alternative to endoscopic assessment 1

Practical Implementation

• Samples for fecal calprotectin testing should be obtained from the first bowel excretion of the day for optimal results 4
• Home testing options using smartphone applications may be available for more frequent monitoring between clinical visits, though these should complement rather than replace standard laboratory testing 5
• The usefulness of the fecal calprotectin test depends on the pre-test probability of IBD - it is most valuable in monitoring known IBD rather than as an indiscriminate screening tool 6