P116 Usefulness of consecutive faecal calprotectin measurements to predict relapse in inflammatory bowel disease patients under maintenance treatment with anti-TNF therapy: a prospective longitudinal cohort study
R. Ferreiro*, M. Barreiro-de Acosta, A. Lorenzo, J. E. Dominguez-Munoz
University Hospital Santiago de Compostela, Gastroenterology, Santiago, Spain
Faecal calprotectin (FC) is a promising tool to monitor the clinical course and to predict relapse in patients with inflammatory bowel disease (IBD). The aim of the study was to evaluate the predictive value of a rapid FC test to predict flares in IBD patients under maintenance anti-TNF therapy.
A prospective, longitudinal cohort study was designed. IBD patients in clinical remission for at least 6 months under a continuous standard dose of 40 mg/eow adalimumab therapy or 5mg/kg infliximab therapy were included. Fresh FC (Quantum blue®rapid test), serum CRP, erythrocyte sedimentation rate, and platelet count were evaluated at 4-month intervals over 1 year. Patients were followed-up and screened for relapse over 16 months (from entry to 4 months after the final FC determination). Relapse was defined as a Harvey–Bradshaw score > 4 in Crohn’s disease (CD) and a partial Mayo score > 3 in ulcerative colitis (UC).The Wilcoxon’s signed-rank test and the ROC analysis were performed.
In total, 106 patients were included (median age 42 years, 54% female, 75% CD and 25% UC). Amongst them, 75 patients (71%) remained in clinical remission over the 16-month study period, whereas the disease relapsed in the remaining 31 patients (29%). FC concentration was significantly higher in those patients who relapsed during the follow-up (528 µg/g, range 234–1 083) than in those who maintained in remission (86µg/g, range 30–237) (p < 0.001). The optimal cut-off of FC to predict remission was 130 µg/g according to the ROC analysis. The area under the ROC curve (AUC) was 0.94 (p < 0.001). Sensitivity, specificity, and positive and negative predictive value of FC to predict relapse were 100%, 80%, 63%, and 100%, respectively. Two consecutive calprotectin measurements >300µg/g were identified as the best predictor of flare (65% sensitivity and 100% specificity). According to ROC analysis, FC was significantly better to predict relapse than C-reactive protein, erythrocyte sedimentation rate, or platelet counts.
In IBD patients under anti-TNF therapy, FC levels allow predicting relapse over the following months with a high accuracy. Low faecal calprotectin levels exclude relapse within at least the following 4 months, whereas 2 consecutive measurements > 300 µg/g are associated with relapse and are much more specific than a single measurement.