P167. Prediction of clinical outcome in Crohn's disease by using confocal laser endomicroscopy: a prospective, observational, follow-up study
G.E. Tontini1,2, J. Mudter3, M. Vieth4, R. Atreya1, C. Günther1, M. Vecchi2,5, M.F. Neurath1, H. Neumann1, 1University of Erlangen-Nuremberg, Medicine I, Erlangen, Germany, 2IRCCS Policlinico San Donato, Gastroenterology and Digestive Endoscopy Unit, San Donato Milanese, Italy, 3Sana Kliniken Ostholstein, Gastroenterology, Eutin, Germany, 4Klinikum Bayreuth, Institute of Pathology, Bayreuth, Germany, 5University of Milan, Department of Biomedical Sciences for Health, Milan, Italy
Assessment of prognostic factors in Crohn's disease (CD) patients is most important for early intervention and “treat to target” strategies. Confocal Laser Endomicroscopy (CLE) enables on demand in vivo characterization of architectural changes during endoscopy. Here, we prospectively evaluated the value of CLE, endoscopic index of severity (CDEIS) and serum C-reactive protein (CRP) for prediction of clinical outcomes in CD.
Consecutive CD patients undergoing colonoscopy with fluoresceine-aided confocal imaging were enrolled in a blind, observational, follow-up study. Consistent with previous reports, CLE analysis focused on two highly reproducible architectural microscopic tissue changes referred as histological hallmarks of acute inflammation in CD: focal cryptitis (FC) and discontinuous crypt architectural abnormality (DCAA).
Thirty-two CD patients were included (14 men; median age/range 37/18–60 years; mean distance from diagnosis 11 years). Baseline CRP was ≥5 mg/L in 46% and CDEIS ≥3 in 73% of patients. Mean follow-up period was 2.5 years (range=6–48 months). FC and DCAA were observed in 63% of patients. This finding showed a weak correlation with CDEIS (P = 0.068, RR = 1.6) and no correlation with CRP (P = 0.4, RR = 1.6). FC and DCAA were significantly associated with an increased risk of medical treatment escalation with biologics, immunosuppressant or systemic steroids within 6 months (P = 0.045, RR = 2.0), showing 75% sensitivity and 70% specificity. This finding was also confirmed at 12 month follow up (P = 0.012, RR = 2.1; sensitivity=76%, specificity=78%). Patients with positive CLE findings developed significantly more transmural complications such as stenosis or perianal disease during the first 12 months (P = 0.023, RR = 6.0; sensitivity=91%, specificity=52%). Conversely, basal CDEIS ≥3 was only associated with treatment escalation at month 12th (P = 0.022, RR = 2.27; sensibility=85%, specificity=37%). CRP was not correlated with prognostic clinical outcomes.
In vivo characterization of CD-related signs of acute inflammation by means of CLE showed moderate correlation with CDEIS but not with CRP. CLE appeared as a good predictor of relevant clinical outcomes such as treatment escalation and transmural complications, performing better than CRP and CDEIS. This finding was substantial in the short term but disappeared after one year follow up. Therefore, endomicroscopic assessment of acute mucosal inflammation appears to be a promising prognostic tool, which may allow early risk stratification of strong clinical outcomes with high sensitivity and moderate to good specificity, thereby potentially improving the timing of treatment strategies targeting mucosal inflammation in CD.