# Performance Evaluation of Open Channel Buhlmann Fecal Calprotectin Turbo Assay on Abbott Alinity C Analyzer

## TL;DR

This paper evaluates a new automated test for measuring fecal calprotectin, a marker for gut inflammation, showing improved efficiency and accuracy in diagnosing inflammatory bowel disease.

## Contribution

The study validates the Buhlmann fCAL turbo assay on the Abbott Alinity C analyzer as a reliable and efficient alternative to ELISA-based fecal calprotectin testing.

## Key findings

- The AFCAL assay showed strong correlation (r = 0.99) and low bias (1.8%) compared to the ELISA-based method.
- Implementation of AFCAL improved turnaround time, reduced cost per test, and increased clinician satisfaction.
- Imprecision studies showed within-run (5.3%) and between-day (2.5%) performance within acceptable limits.

## Abstract

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal (GI) tract. Fecal calprotectin (fCAL) is a noninvasive laboratory test used in the diagnosis and monitoring of IBDs such as Crohn’s disease and ulcerative colitis. The fCAL send-out test that our facility has been offering so far uses an ELISA-based method. In the current study, we sought to validate the performance of a Buhlmann fCAL turbo assay in an automated Abbott Alinity C analyzer (AFCAL) in our core laboratory. Five-day imprecision studies showed good performance for both within-run (5.3%) and between-day (2.5%) measurements. The reportable range was verified as 30–20,000 µg/g. Deming regression and Bland–Altman analysis indicated a strong correlation of r = 0.99 with a low, acceptable bias of 1.8% for AFCAL relative to the predicate Buhlmann fCAL ELISA results. AFCAL’s clinical performance was determined retrospectively in 62 patients with ICD codes for IBD. Overall, the implementation of AFCAL in our routine clinical testing has improved our turnaround time, reduced the cost per test, and significantly increased our clinician satisfaction.