P221. Faecal calprotectin concentrations in Crohn's patients with ileal disease location: correlations with disease activity as seen by MRI enterography
F. Fascì-Spurio1, A. Chiappini1, V. Buonocore2, S. Cannizzaro1, Z. Maddalena1, F. Maccioni2, P. Vernia1, 1Sapienza University, Gastroenterology Unit, Policlinico Umberto I, Rome, Italy, 2Sapienza University, Radiology Department, Policlinico Umberto I, Rome, Italy
Faecal Calprotectin (FC) is considered a reliable marker of disease activity in IBD. While its correlation with colonic inflammation has clearly been established, its correlation with ileal inflammation has never been thoroughly investigated and its clinical reliability in patients with ileal CD remains controversial.
As MRI enterography is considered of prime importance for assessing disease activity in patients with ileal CD, aim of the present study has been to investigate the correlation between MRI findings and FC.
A series of consecutive patients with known CD referred for MRI enterography at a single institution between December 2010 and June 2013 were prospectively recruited.
Out of the 114 patients initially considered for enrolment, we included in the analysis 47 patients with ileal or ileocaecal disease location (L1 phenotype according to the Montreal classification). Demographics: Female 47%; median age at MRI: 37 years (95% CI 28–43), median disease duration at MRI: 7 years (95% CI 3–15); Montreal disease behaviour: B1 42%; B2 39%; B3 19%; perianal disease in 17%; resectional surgery related to CD before MRI in 43%.
Participants completed an HBI symptom questionnaire and provided a stool sample on the same day of the MRI. Clinical and demographic data were recorded by their attending physicians.
Two radiologists with experience in MRI enterography, blinded to patients' data, separately analysed several MRI parameters including: wall thickening, T2 wall signal intensity, wall Gadolinium enhancement, perivisceral oedema, active lymph nodes and local abscesses/phlegmons. The MRI parameters were graded on a scale from 0 to 3, according to a previously published scoring system. A final activity score ranging from 0 to 18 was then calculated.
MRI enterography showed active disease in 40 patients and quiescent disease in 7. Median FC concentrations in the two groups were, respectively, 205 mg/kg (95% CI 121–247) and 69 mg/kg (95% CI 15–182); p < 0.0035. Median HBI scores were 4 (95% CI 0–16) and 5 (95% CI 4–6); p < 0.12. ROC analysis for FC against ileal inflammation showed AUC 0.825 (95% CI 0.671–0.979); a FC cut-off of 110 mg/kg offered 76% sensitivity and 70% specificity for any degree of active ileal inflammation.
The MRI score in our cohort ranged between 0 and 15. Spearman analysis showed a moderate positive correlation between FC values and MRI degrees of activity: R=0.515; p < 0.0002.
This study suggests that in patients with CD involving the ileum FC shows good correlation with MRI findings of active disease. It is thus suggested that FC represents a reliable parameter for evaluating inflammatory activity not only of the colon, but also the ileum.