P416 Is faecal calprotectin (FC) a reliable marker of isolated small bowel Crohn's disease (CD) activity?
B. Warner*1, E. Johnston1, M. Ward2, P. Irving1
1Guy's and St Thomas' NHS Foundation Trust, Department of Gastroenterology, London, United Kingdom, 2The Alfred Hospital, Department of Gastroenterology, Melbourne, Australia
FC is considered a useful diagnostic tool in both the diagnosis and assessment of activity in CD. However,accuracy in small bowel disease(Montreal classification L1) compared to colonic(L2) and ileocolonic(L3) remains undetermined. We aimed to establish whether FC can be used to assess disease activity in L1 disease with the same degree of confidence as other disease locations.
Prospective evaluation of 197 consecutive patients receiving treatment with infliximab or adalimumab. All patients had FC measured (all FC in units of IU/ml)
at the same time as C-Reactive Protein(CRP) and Harvey Bradshaw Index(HBI). Active disease was defined as HBI ≥ 5 and/or CRP >5. FC for comparisons were Log10 transformed. Significances between means were obtained using independent 2 sample t-test and the oneway ANOVA test.
Patients were divided according to Montreal classification; L1(n=28),L2(n=59) and L3(n=108). Mean FC for the 3 groups were 344(median=100),379(median=80) and 288(median=71) respectively(P=0.728). There was a significant difference in FC between those with active disease and remission (543 versus 216 P< 0.015). The association between FC and disease activity were made between the 3 disease locations are shown in table.
Table: Demonstrating significance of the relationship between the mean FC of patients at specific disease locations according to disease activity based on HBI, CRP or both. “Fig1”
Active disease by HBI or CRP Active disease by HBI alone Active disease by CRP alone L1 P=0.95 (Fig1) P=0.78 P=0.67 L2 P=0.05 (Fig2) P=0.78 P<0.01 L3 P<0.01 (Fig2) P<0.01 P<0.01
Table: Demonstrating significance of the relationship between the mean FC of patients at specific disease locations according to disease activity based on HBI, CRP or both.
FC was associated with disease activity in colonic and ileocolonic disease. FC could not discriminate between active disease and remission for isolated small bowel disease. Assessment of patients with isolated disease should include other modalities(cross-sectional imaging and endoscopy).