P482. Faecal calprotectin can be used to monitor response to therapy in anti-TNF treated patients with Crohn's disease
R. Saleem, P. Dubois, G. Chung-Faye, I. Bjarnason, B. Hayee, King's College Hospital NHS Foundation Trust, Gastroenterology, London, United Kingdom
Faecal calprotectin (FCALP) is a reliable and sensitive marker of intestinal inflammation in IBD, often used to differentiate between IBD and IBS. Emerging evidence also indicates that it can be used to monitor disease activity in a longitudinal fashion. FCALP would be also an attractive method to monitor response to therapy.
A retrospective analysis of the hospital electronic patient record was conducted to evaluate our institution's protocol of measuring FCALP at regular intervals before and during therapy for IBD. Intervals were before therapy, at 4 months (after 4th infusion) and 12 months. HBI recorded at the same intervals (with remission indicated by score ≤5) and objective assessment of mucosal healing (MH) was also analysed. Patients were stratified according to whether FCALP “normalised” at 4 months of anti-TNF therapy (<60 mcg/g), “responded” (decreased by ≥50%), or “did not respond” (all other Δ).
33 patients (20F) with complete data sets and long-term follow-up were identified, mean age 38.8±13.6 years. Mean duration of disease and anti-TNF was 11.1±8.8 years and 42.2 months (range 12–144), respectively. 9 patients had ileal, 8 colonic and 16 ileocolonic disease location. 10 patients had stricturing disease, 9 penetrating and 6 perianal. Median FCALP at baseline was 985 (570–4800) µg/g, with HBI 9 (8–17). At 4 months using the above criteria for FCALP, 12 patients normalised, 12 responded and 9 did not. Remission at 12 months was recorded in 10/12 (83%) normalisers, 8/12 (67%) responders (grouped for analysis 18/24) and 2/9 (22%) non-responders (OR 10.5, 95% CI 1.7–65.0, p = 0.01). MH data is incomplete, but colonoscopy was performed in 7 normalisers and demonstrated MH in all cases. FCALP was consistently and highly significantly correlated with HBI in a linear fashion at 4 months and across all time-points (for both, R2 0.53, p < 0.0001).
FCALP can be used to monitor response to anti-TNF therapy in Crohn's disease and provides an objective marker of inflammation. When measured at the 4-month timepoint, FCALP appears to be an excellent predictor of which patients will respond and remain in remission. Normalisation of FCALP correlates closely with mucosal healing.