Clinical and Analytical Characterization of the DiaSorin and ScheBo Fecal Pancreatic Elastase 1 Assays.

OBJECTIVES: Fecal pancreatic elastase (PE) assays are screening tests for exocrine pancreatic insufficiency (EPI). We analytically evaluated a new PE assay and retrospectively analyzed data from an academic hospital and reference laboratory to understand the clinical utility. METHODS: Forty stool samples with different PE concentrations were tested on the ScheBo enzyme-linked immunosorbent assay (ELISA) versus DiaSorin LIAISON immunoassay; a simple-to-use extraction device was assessed. The cross-reactivity of porcine enzymes was investigated in the immunoassay. Charts of 207 patients with PE results less than 250 µg/g at an academic hospital were reviewed, and data were analyzed for 5136 patients with repeat PE results from a reference laboratory. RESULTS: The LIAISON immunoassay gave comparable results to the ScheBo ELISA, with 87.5% agreement of PE results in classifying as sufficient, mild/moderate insufficiency, or severe insufficiency. The extraction device worked well compared with manual weighing, and no cross reactivity with porcine enzymes was observed. In agreement with prior studies, our clinical data suggested that PE assays were most useful in detecting severe EPI. CONCLUSIONS: The new DiaSorin LIAISON immunoassay preforms similarly to the well-known ScheBo ELISA. Pancreatic elastase assays can help identify patients with severe EPI but are not as useful in classifying mild/moderate EPI.

Comparison of Next-Generation Assays for Fecal Calprotectin vs the PhiCal Assay.

OBJECTIVES: To compare the PhiCal assay (CALPRO), the first US Food and Drug Administration-approved assay for fecal calprotectin, to 4 next-generation assays. METHODS: Stool samples from 50 patients were selected, and relevant clinical information was collected. Comparisons were performed using the PhiCal, fCAL turbo (BÜHLMANN), LIAISON Calprotectin (DiaSorin), QUANTA Lite Calprotectin ELISA (Inova Diagnostics), and Calprotectin Chemiluminescence ELISA (ALPCO) assays. RESULTS: All 4 assays had acceptable agreement with PhiCal when qualitatively categorizing results. Within the PhiCal reportable range of 16 to 1,250 µg/g, the DiaSorin, Inova Diagnostics, and ALPCO assays had Spearman correlation coefficients of 0.98, 0.97, and 0.95 and positive biases of 17%, 20%, and 15%, respectively. The BÜHLMANN assay ran approximately 2-fold higher than the PhiCal assay but had a correlation coefficient of 0.98, with similar result categorization. CONCLUSIONS: Our results demonstrate good comparison between PhiCal and 4 next-generation assays. Laboratories performing fecal calprotectin assays may have compelling reasons to adopt next-generation fecal calprotectin testing, such as greater automation, a decreased number of replicates needed per test, and the use of stool-extraction devices. These benefits could decrease turnaround times and lower costs. Although the results of the assays correlated, they are not standardized. Laboratories adopting the newer assays will need to further investigate their performance through validation studies.

Clinical and Analytical Verification of an Automated Fecal Calprotectin Immunoassay with Extraction Device.

BACKGROUND: Fecal calprotectin (FC) is a screening test for intestinal inflammation, and often used by clinicians to help identify and monitor patients with inflammatory bowel disease (IBD). Improvements in FC assays include moving to more automated immunoassays compared to ELISAs and simple-to-use extraction devices compared to manual weighing for the extraction process. METHODS: A method comparison was performed between the PhiCal ELISA and LIAISON immunoassay for 53 stool samples, and the screening results were compared to the gold standard endoscopy with biopsy results. Clinical accuracy was assessed by comparing the FC results from each assay to the presence or absence of inflammation determined from the biopsy report. The performance of the extraction device was compared to manually weighing. Additional studies were completed to verify the manufacturer's claims. RESULTS: The FC results were compared to the biopsy results for detecting inflammation. PhiCal ELISA had a sensitivity of 86% and specificity of 100%, while the LIAISON immunoassay had a sensitivity of 97% with specificity of 94%. Therefore, the LIAISON immunoassay performed better than the PhiCal ELISA. The extraction device performed well compared to manual weighing if stool samples were <800 µg/g, within Bristol stool types 2-6, and did not contain a significant amount of undigested material, fibrous material, or mucus. CONCLUSION: The LIAISON immunoassay with extraction device has acceptable performance for clinical use in measuring fecal calprotectin.