Fecal Calprotectin and Segmental Inflammation in Small Bowel Crohn's Disease: A Capsule Endoscopy-Based Study

Area of Science:

• Gastroenterology
• Inflammatory Bowel Disease
• Diagnostic Markers

Background:

• Fecal calprotectin (FC) is a marker for gastrointestinal inflammation.
• Its utility in detecting small bowel (SB) inflammation in Crohn's Disease (CD) is debated.
• Small bowel capsule endoscopy (SBCE) is a key diagnostic tool for SB inflammation.

Purpose of the Study:

• To investigate the association between FC levels and SB inflammatory activity in CD patients.
• To determine the reliability of FC in identifying inflammation across different SB segments.
• To establish FC cutoffs for differentiating disease patterns.

Main Methods:

• Retrospective cohort study of 87 SB-CD patients undergoing SBCE and FC testing.
• Exclusion of patients with concurrent colonic inflammation.
• Classification of SB inflammation based on Lewis Score (LS) in proximal, distal, or pan-SB tertiles.

Main Results:

• FC levels showed an ascending trend with increasing SB inflammation: 58 µg/g (no inflammation) to 400 µg/g (pan-SB inflammation).
• FC correlated with LS in the second and third SB tertiles, but not the first.
• FC was significantly higher in pan-SB disease versus isolated proximal or distal inflammation.

Conclusions:

• FC positively correlates with SB lesions in the distal SB (second and third tertiles).
• FC is not a reliable marker for proximal SB inflammation (first tertile).
• SBCE remains crucial for diagnosing proximal SB inflammation in CD patients.