Background: Identify predictors of therapeutic response is the cornerstone of personalized medicine. The aim of this study was to identify predictors of endoscopic remission in patients with CD at one year of treatment with TNF inhibitors.
Methods: This is a single center prospective study initiated in November 2012. Patients with clinically active luminal CD, with a baseline segmental Crohn's Disease Endoscopic Index of Severity (CDEIS) equal or higher than 10 in at least one segment or presence of ulcerations were included in the study. Patients were treated with anti-TNF therapy for induction of remission, and maintenance. Clinical, biological and endoscopic data were obtained at baseline, week 14 and week 46. Endoscopic response was defined as a decrease of 50% from baseline CDEIS and remission as partial CDEIS lower or equal to 5 (disappearance of mucosal ulcerations) in all segments.
Results: To date, 61 patients have been included, of whom 43 have completed week 46 follow-up. Thirty (49%) are female with a mean disease duration of 9 years. Thirty two out of 61 (52%) received Infliximab and 29 (48%) Adalimumab. At baseline, median CDAI and CDEIS were 181 and 9,07 with a significant reduction after one year of treatment up to 71,2 (p<0.001) and 4,2 (p<0.001), respectively. At week 14, 64.5% of patients achieved endoscopic response and 37% endoscopic remission. At week 46, percentages of endoscopic response and remission were 56% and 46%, respectively. Demographic or disease characteristics at baseline did not predict endoscopic response to induction or maintenance therapy. Predictors of endoscopic remission at week 46 were the absolute CDEIS value at week 14, percentage of CDEIS reduction from baseline to week 14, and endoscopic remission. Based on the clinical usefulness of the evaluated cutoff values a decrease from baseline CDEIS of at least 80% appeared to be the best discriminative cutoff value to predict endoscopic remission at week 46 with 68% sensitivity and 85% specificity (p=0.002).
Conclusions: In patients with CD treated with an anti-TNF a reduction of 80% in CDEIS from baseline to week 14 is a robust predictor of endoscopic remission after one year of treatment. Achievement of this endpoint should be considered for optimization of anti-TNF therapy in clinical practice.