Analytical Performance and Clinicopathologic Correlation of Four Fecal Calprotectin Methods

Objectives: Calprotectin is a noninvasive biomarker that can distinguish inflammatory bowel disease from irritable bowel syndrome. We investigated four automated fecal calprotectin methods on five different platforms for their preanalytical process, analytical performance, and clinicopathologic correlation.

Methods: Four calprotectin methods (Bühlmann, EliA CN, EliA CN2, and DiaSorin) were performed on five platforms (Cobas 8000 E502, Phadia Immunocap 100 and 250, and Liaison and Liaison XL) in two hospital laboratories.

Results: Overall variation for the different extraction devices was less than 19% when feces were of normal consistency. Freeze-thawing of samples resulted in comparable results compared with fresh samples. The different methods had a good analytic correlation (R = 0.83-0.95). Their clinicopathologic correlation was comparable, but the Bühlmann method showed significantly higher calprotectin values in every patient category.

Conclusions: The automated calprotectin methods showed a good performance and comparable clinicopathologic correlation. Due to lack of standardization, the numerical values differ for the various methods.