Fecal calprotectin in pediatric gastrointestinal diseases: Pros and cons

Table 1 Comparison between serum and fecal calprotectin

Aspect	Serum calprotectin	Fecal calprotectin
Purpose	Marker of systemic inflammation	Marker of intestinal inflammation
Source	Neutrophils in the bloodstream	Neutrophils in the intestinal mucosa
Production	Neutrophils release calprotectin into the bloodstream during systemic inflammation	Neutrophils migrate to gut mucosa during inflammation, releasing calprotectin into the intestinal lumen
Method of measurement	Blood tests (serum) using techniques like ELISA or immunoassays	Stool samples using techniques like ELISA
Sample ‎stability	Stable at room ‎temperature for shorter ‎periods	Requires refrigeration and ‎prompt analysis
Clinical utility	Less commonly used. Monitor overall systemic inflammatory status; response to treatment	Widely used. Distinguish between GI disorders; assess disease activity
Role in pediatric GI disorders	Less specific to GI disorders, it may not reflect the severity of GI inflammation	Highly specific to GI inflammation; aids in diagnosis and monitoring of GI disorders
Advantages	Provides systemic inflammation status	Non-invasive; reflects intestinal inflammation accurately
Limitations	Less specific to GI disorders; not as accurate for GI evaluation, influenced by systemic inflammation	Invasive; requires stool sample collection; influenced by extraintestinal factors
Reference range	Lower levels, < 50 μg/mL	Higher levels, < 50 μg/g
Interpretation	Limited evidence for clinical interpretation	Established cutoffs for clinical interpretation
Cost	Typically, higher cost	Generally lower cost
Availability	May require specialized testing facilities	Widely available

ELISA: Enzyme-linked immunosorbent assay; GI: Gastrointestinal.