What does a calprotectin level of 94.3 indicate?

Interpretation of Calprotectin Level 94.3 μg/g

A calprotectin level of 94.3 μg/g falls in the mildly elevated range, suggesting possible intestinal inflammation that requires clinical correlation but is below the threshold for definitive inflammatory bowel disease diagnosis. 1, 2

Understanding Calprotectin Values

Fecal calprotectin is a surrogate marker of intestinal inflammation that correlates well with endoscopic inflammation in both ulcerative colitis and Crohn's disease. The British Society of Gastroenterology guidelines provide the following interpretive thresholds:

• <50 μg/g: Normal/Negative (high negative predictive value for ruling out IBD)
• 50-100 μg/g: Mildly elevated (borderline)
• 100-250 μg/g: Intermediate elevation (consider referral to gastroenterology)
• >250 μg/g: Significantly elevated (high specificity for active intestinal inflammation)

Clinical Significance of 94.3 μg/g

Your calprotectin level of 94.3 μg/g indicates:

• It falls just below the intermediate range (100-250 μg/g) 1
• Has higher sensitivity (>90%) but lower specificity for detecting intestinal inflammation 2
• May represent mild inflammation but could also be a false positive 1, 2

Diagnostic Algorithm Based on Calprotectin Level

1. For values <50 μg/g:

   • High negative predictive value for IBD (>90%)
   • Consider non-inflammatory conditions like IBS

2. For values 50-100 μg/g (your result falls here):

   • Consider:
     • Mild IBD activity
     • Early IBD
     • Other causes of mild inflammation
   • Clinical correlation required

3. For values 100-250 μg/g:

   • Moderate probability of IBD
   • Gastroenterology referral recommended

4. For values >250 μg/g:

   • High specificity (82%) for active IBD 1, 2
   • Urgent gastroenterology referral indicated

Important Considerations

• False positives: NSAID use within 6 weeks can falsely elevate calprotectin levels 2
• Sample collection: First morning stool is recommended; samples should be analyzed within 3 days if kept at room temperature 1
• Topographical gradient: Calprotectin levels increase from proximal to distal bowel segments for similar inflammatory activity 3
• Differential diagnosis: Elevated levels can occur in:
  • Inflammatory bowel disease
  • Infectious enteritis
  • Colorectal cancer
  • Microscopic colitis 4

Next Steps Based on Your Result

1. Clinical correlation:

   • Assess for symptoms (diarrhea, abdominal pain, rectal bleeding)
   • Review medication history (especially NSAIDs)
   • Evaluate for alarm symptoms (weight loss, anemia)

2. If symptoms suggest possible IBD:

   • Consider repeat testing in 4-6 weeks
   • If symptoms persist or worsen, referral to gastroenterology is appropriate despite borderline value 2

3. If no concerning symptoms:

   • Monitor clinically
   • Consider repeat testing if symptoms develop or worsen

Remember that calprotectin is a screening tool and not a definitive diagnostic test. The interpretation must always consider the clinical context and patient's symptoms.