PWE-016 Faecal Calprotectin Has an Acceptable Sensitivity for Detecting Small Bowel Crohn’s Disease: Results from Real World Clinical Practice
Bibliographic record
Abstract
Introduction Faecal calprotectin ‘FC’ is a quick, non-invasive and inexpensive test proven to correlate well with colonic inflammation. It is used in our institution to also exclude active small bowel Crohn’s disease ‘CD’ although its reliability in such cases has recently been questioned. Using a higher cut-off FC value may exclude active disease in those with known inflammatory bowel disease with a higher specificity and reduce the number of false positives.1,2 The aim of this study was to assess whether FC compared to gold standard magnetic resonance enterography ‘MRE’ can reliably be used in small bowel CD as a screening tool to select those needing further investigation. Methods Data from all CD patients who had undergone MRE to assess for active small bowel CD between January 2012 to November 2015 were reviewed. Patients with a known or new diagnosis of ileal or ileo-caecal crohn’s (Montreal classification L1 phenotype) or ileo-colonic crohn’s (L3 phenotype) with endoscopic and histologically-proven quiescent colonic disease were included. Data was analysed using Mann-Whitney U testing. Results 194 MREs were performed for investigation of possible small bowel CD during the study period. 64 patients were included for analysis; L1 disease = 90.6% (58 patients), L3 = 9.4% (6 patients). 50% were female. The median age was 48 years (range 17–76 years). Median time between FC and MRE was 30 days (range 0–180 days). 35 patients (54.7%) were Montreal disease behaviour B1, 24 patients (37.5%) with B2 and 5 patients (7.8%) with B3. 4 patients (6%) had peri-anal involvement. 26 patients (41%) had previous Crohn’s-related resectional surgery. 39 patients (60.9%) had evidence of active small bowel CD at MRE. The median FC in the active CD group was 246 mg/kg (IQR 556) and 49 mg/kg for the inactive small bowel disease group (IQR 177.5); p < 0.0001. Table 1 shows results for sensitivity, specificity, positive predictive value ‘PPV’ and negative predictive value ‘NPV’ of different FC cut-off values in detecting any degree of small bowel activity at MRE. Conclusion In this study we compared FC results to MRE to exclude or confirm active small bowel CD in real-world clinical practice. This data demonstrates that by using a cut-off value of 50 mg/kg, an acceptable sensitivity for detecting active small bowel CD is achievable. However, at this cut-off value, specificity is low; nevertheless using FC will still reduce demand for MRE. References 1 F. Fascì-Spurio, A. Chiappini, V. Buonocore, S. Cannizzaro, Z. Maddalena, F. Maccioni, P. Vernia. (2014) Faecal calprotectin concentrations in Crohn’s patients with ileal disease location: correlations with disease activity as seen by MRI enterography. European Crohn’s and Colitis Organisation. 2 MF Hale, K Drew, ME McAlindon, AJ Lobo, R Sidhu. (2015). PTU-054 Faecal calprotectin in patients with suspected small bowel crohn’s disease: correlation with small bowel capsule endoscopy. Gut2015;64:A83. doi:10.1136/gutjnl-2015-309861.169 Disclosure of Interest None Declared
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.007 | 0.023 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".