Analytical Performance and Clinicopathologic Correlation of Four Fecal Calprotectin Methods

Distinguishing inflammatory bowel disease from irritable bowel syndrome remains a diagnostic challenge. Calprotectin has emerged as a potential noninvasive tool for this purpose. Prior research has shown that fecal calprotectin can reflect intestinal inflammation. However, no prior work had resolved the variability between automated testing methods. That uncertainty drove this investigation into the performance of different calprotectin assays. It was already known that calprotectin levels correlate with disease activity. This gap motivated the need to assess analytical consistency across platforms. No prior work had resolved how sample preparation affects results. This study aimed to clarify these issues. The lack of standardization in calprotectin testing remains a barrier to widespread adoption.

The authors aimed to evaluate the analytical performance and clinicopathologic correlation of four fecal calprotectin methods. They sought to compare these methods across different platforms in clinical settings. The specific problem addressed was the lack of standardization in calprotectin testing. This study aimed to clarify how sample preparation affects results. The motivation stemmed from the diagnostic uncertainty between IBD and IBS. The authors wanted to assess whether the methods produce consistent results. They also aimed to determine if clinicopathologic correlation is affected by the method used. The ultimate goal was to guide clinical practice in selecting reliable calprotectin assays.

The researchers selected four calprotectin methods for evaluation. These methods were tested on five different platforms in two hospital laboratories. The methods included Bühlmann, EliA CN, EliA CN2, and DiaSorin. They assessed preanalytical processes, including sample consistency and freeze-thawing. The study compared results from fresh and frozen fecal samples. They evaluated overall variation in calprotectin measurements. The clinicopathologic correlation was analyzed across patient categories. The study design allowed for direct comparison of method performance.

The study found overall variation of less than 19% for normal consistency feces. Freeze-thawing had minimal impact on calprotectin measurements. Analytic correlation between methods ranged from R = 0.83 to 0.95. Clinicopathologic correlation was consistent across methods. The Bühlmann method showed significantly higher calprotectin values. This difference was observed in all patient categories tested. The methods demonstrated good analytical performance overall. However, numerical values varied due to lack of standardization.

The authors concluded that automated calprotectin methods perform well analytically. They found comparable clinicopathologic correlation across methods. The Bühlmann method consistently reported higher calprotectin levels. This suggests variability in numerical output between platforms. The lack of standardization remains a limitation. The study supports the use of calprotectin in clinical settings. However, method-specific reference ranges are necessary. These findings highlight the need for standardized calprotectin testing protocols.