Introduction: Calprotectin, a calcium- and zinc-binding protein predominantly found in neutrophils, has emerged as a pivotal biomarker in clinical diagnostics due to its role in inflammatory processes. Elevated levels of calprotectin are indicative of neutrophil activation and migration, making it a valuable marker for detecting and monitoring inflammation. Currently, delays in testing with ELISA and closed-assay systems represent multi-day delays, as those methods are generally not available or used in many hospitals. We introduce an FDA-approved method that can be tested on open immunoassay analyzers, commonly found in hospitals, with determination in as little as 10 minutes.
Methods: Patients (male and female) presenting with possible inflammatory intestinal disease or irritable bowel syndrome with symptoms such as abdominal pain, diarrhea, altered appetite, weight loss, or anemia, scheduled for ileocolonoscopy, were eligible for the study. Patients submitted stool samples for evaluation 24-48 hours before the colonoscopy or 3-14 days afterwards. A total of 349 patients, ages 22-86, were included in the study.
The submitted stool samples were extracted and run in the ALPCO Calprotectin Immunoturbidimetric (IT) assay using a Beckman AU680 Analyzer. Diagnostic sensitivity and specificity were evaluated against the results of the colonoscopy outcomes. A random subset of the samples (n=20, 8 with IBD, 12 with IBS or other diagnosis), spanning the analytical measuring range of the assay, were also independently evaluated against the following FDA-approved methods: Buhlmann fCAL Turbo, Diasorin LIASON and the Inova QUANTA Flash.
Python was used for determination of sensitivity and specificity.
Results: In the full cohort, diagnostic sensitivity was determined to be 90.5% (95% CI: 80.7–95.6%) and diagnostic specificity was calculated at 93.4% (95% CI: 89.9–95.7%). Determinations were made using a clinical cutoff of 50 µg/g.
In the subset cohort, the analytical sensitivities and specificities are listed in Table 1: Method Comparison.
Discussion: The ALPCO Calprotectin IT demonstrates excellent sensitivity and specificity against clinical colonoscopy while displaying favorable results against other FDA-approved methods.
Note: The table for this abstract can be viewed in the ePoster Gallery section of the ACG 2024 ePoster Site or in The American Journal of Gastroenterology's abstract supplement issue, both of which will be available starting October 27, 2024.
Disclosures:
Chris Wisherd: ALPCO – Employee.
Amy Willson: ALPCO – Employee.
Chris Wisherd, BSc, Amy Willson, . P2677 - Evaluation and Method Comparison of a Rapid Automated Fecal Calprotectin Assay in Patients Suspected of Having Inflammatory Bowel Disease, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.
