P155 Comparison of video capsule endoscopy and faecal calprotectin as diagnostic tools in patients with abdominal symptoms suggestive of small bowel Crohn's Disease
K.V. Patel*, S. Zaman, S. Fong, S.H. Anderson
Guy's and St Thomas' NHS Foundation Trust, Gastroenterology, London, United Kingdom
Faecal calprotectin (FC) is a widely agreed non-invasive marker of gastrointestinal (GI) inflammation. There is a dearth of evidence comparing FC levels to findings of video capsule endoscopy (VCE). Particularly, there is a scarcity of data investigating the suitability of FC as a screening tool to select individuals requiring VCE in the investigation of patients with abdominal symptoms suggestive of small bowel Crohn's Disease (CD). We studied the correlation between FC levels and VCE findings and analysed their combined utility in detecting small bowel CD.
We retrospectively compared VCE findings and FC levels in adult patients referred with GI symptoms (abdominal pain, diarrhoea, weight loss, anaemia and bloating). Where multiple FC were measured, the value closest to the date of VCE was used. History of non-steroidal anti-inflammatory drugs, aspirin, clopidogrel and prednisolone use in the six weeks prior to VCE were identified. Findings of relevant investigations (GI endoscopy, MRI, CT, coeliac serology, histology, haemoglobin, C-reactive protein and platelet count) were also reviewed. FC and VCE findings were analysed against final diagnosis.
62 patients were studied (21 males, mean age 41). One study was excluded due to capsule retention in the stomach. The median time between FC and VCE was 92 days. 29 had a normal FC (< 60mg/g, mean 18mg/g) of whom 5 had abnormal VCE findings (17.2%). 32 had a raised FC ( >60mg/g, mean 263mg/g) of whom 7 had abnormal VCE findings (21.9%). Two-tailed Fisher's exact test revealed that the difference between the two groups was not statistically significant (p=0.75).
In the normal FC/abnormal VCE group 3 out of 5 patients were diagnosed with CD (one had CD confirmed on colonoscopy). One case had mild patchy terminal ileal (TI) erythema. Another had non-specific TI aphthous ulcers. In the raised FC/abnormal VCE group 3 out of 7 patients were diagnosed with CD (all 3 had active CD on colonoscopy). Two cases had jejunal apthous ulcers, and there was one case each of mild patchy TI erythema and TI apthous ulcers. Two-tailed Fisher's exact test revealed that the difference between these two groups was also not statistically significant (p=1).
The utility of FC to diagnose small bowel CD remains debatable, with previous studies showing differing outcomes. In our cohort, FC levels did not reliably correlate with VCE findings. The correlation of FC level with the diagnosis of small bowel CD by VCE was also not statistically significant. Based on our findings, the decision to proceed to VCE should be based on clinical symptoms, and not on abnormal FC levels.