Z Gastroenterol 2012; 50 - K189
DOI: 10.1055/s-0032-1324124

Assessment of the process of mucosal healing in ulcerative colitis upon anti-TNF therapy by using confocal laser endomicroscopy

G Hundorfean 1, MT Chiriac 1, 2, A Hartmann 3, MF Neurath 1, J Mudter 1
  • 1Medizinische Klinik 1, Universitätsklinikum Erlangen, Erlangen, Germany
  • 2Babes-Bolyai University Institute for Interdisciplinary Research on Bio-Nano-Sciences, Molecular Biology Center, Cluj-Napoca, Romania
  • 3Institut für Pathologie, Universitätsklinikum Erlangen, Erlangen, Germany

Mucosal healing (MH) is the main goal in the treatment of IBD, incl. ulcerative colitis (UC). Monitoring MH might be important to evaluate therapy response and the course of disease. The endoscopic assessement of MH using white light endoscopy (WLE) comprises many macroscopic scores. The analysis of the mucosal microstructure using confocal laser endomicroscopy (CLE) might give new insights into MH during therapy and define more precisely MH.

The aim was to investigate the utility of CLE for assessing microscopical mucosal changings before and after start of infliximab (IFX) therapy in UC and to provide and validate the first endomicroscopical MH-score (eMHS). CLE-morphological criteria (crypt number, distortion, crypt erosions/ulcerations, goblet cell ratio, vascular leakage and cellular infiltrates) were evaluated and eMHS was established.

Consecutive UC patients (Mayo>6) were prospectively included and underwent colonoscopy with CLE before and after 3 IFX infusions. Based on the Mayo-score, 2 groups i.e. therapy responders (Mayo<3) and nonresponders (Mayo>3) were defined. Further, a total of 300 random endomicrographs were analyzed in a blinded fashion by 2 endoscopists, as follows: 100 micrographs from responder group before and 100 micrographs after 3 IFX infusions; 50 random micrographs were analyzed from the non-responder group before and 50 after IFX therapy- based on the eMHS ranging from 0 to 9.

Post-IFX, responder group patients showed an increase in crypt number and a decrease of eMHS. The differences between these two parameters were statistically significant in the responder group (P<0,0001, in the unpaired t test). In the non-responder group, the differences between the pre- and post-treatment scores were not statistical significance (P=0,3362, in the Mann Whitney test). MH was defined as eMH score 0. CLE residual activity, not visible using WLE, ranged from eMHS 0–3 and consisted in enlarged crypt lumen, leakage or hypervascularity.

Our new CLE classification system showed excellent accuracy with the therapy response assessed by clinical and endoscopic Mayoscore. Furthermore, microscopic aspects allow a more precise assessment of MH. CLE can accurately assess MH in vivo based on the newly developed and statistically validated eMHscore for UC.