What is the treatment for elevated calprotectin (fecal calprotectin) levels in stool indicating gastrointestinal inflammation?

Treatment for Elevated Fecal Calprotectin Levels

The treatment for elevated fecal calprotectin should be guided by the severity of symptoms and the degree of elevation, with endoscopic assessment recommended for mild symptoms and empiric treatment adjustment for moderate to severe symptoms with levels >150 μg/g.1

Assessment of Elevated Fecal Calprotectin

• Fecal calprotectin >150 μg/g indicates active intestinal inflammation, particularly in inflammatory bowel disease (IBD) 1
• The approach to treatment differs based on symptom severity and calprotectin levels 1
• A cutoff of 250 μg/g has been associated with the presence of large ulcers in Crohn's disease with 60.4% sensitivity and 79.5% specificity 2

Treatment Algorithm Based on Symptoms and Calprotectin Levels

For Patients with Moderate to Severe Symptoms (frequent rectal bleeding, significant increase in stool frequency):

• With calprotectin >150 μg/g: Initiate or adjust treatment without requiring endoscopic assessment 1
  • Consider appropriate IBD therapy based on disease type and severity 1
  • Options may include biologics such as infliximab for moderate to severe disease 3
  • Monitor response with repeat calprotectin testing in 2-4 months 4

For Patients with Mild Symptoms (infrequent rectal bleeding or slight increase in stool frequency):

• With calprotectin >150 μg/g: Endoscopic assessment is recommended before treatment adjustment 1
• With calprotectin <150 μg/g: Endoscopic assessment is still suggested rather than empiric treatment 1

For Patients in Symptomatic Remission:

• With calprotectin <150 μg/g: No intervention needed; indicates absence of active inflammation 1
• With calprotectin >150 μg/g: Endoscopic assessment is recommended rather than empiric treatment adjustment 1
  • Alternative approach: Repeat measurement in 3-6 months; if still elevated, proceed with endoscopy 1

Special Considerations

• In patients who recently achieved symptomatic remission after treatment adjustment, a lower cutoff of calprotectin <50 μg/g may be preferred to detect endoscopic improvement 1
• For patients with anemia and evidence of ulceration (e.g., in Crohn's disease), more aggressive therapy with biologics is indicated regardless of calprotectin values 4
• Fecal calprotectin correlates better with histological findings than with macroscopic endoscopic findings 5, making it a valuable tool for monitoring subclinical inflammation

Pitfalls and Caveats

• Normal calprotectin (<150 μg/g) with moderate to severe symptoms does not exclude active inflammation; endoscopy may still be needed 1
• False positive rates of 4.6% exist when using calprotectin >150 μg/g to diagnose moderate to severe endoscopic activity 1
• False negative rates of 24.7% exist when using calprotectin <150 μg/g to rule out moderate to severe endoscopic activity in symptomatic patients 1
• Different assays for fecal calprotectin may have different sensitivities and specificities at given cutoff values 6
• Calprotectin levels may not correlate well with symptoms in Crohn's disease, unlike in ulcerative colitis 2

Monitoring Response to Treatment

• Repeat fecal calprotectin measurement 2-4 months after initiating or adjusting therapy 4
• Consider endoscopic assessment 6-12 months after treatment initiation to confirm mucosal healing 1, 4
• For patients with elevated calprotectin but in symptomatic remission, repeat measurement in 3-6 months before proceeding to endoscopy 1