Endoskopie heute 2012; 25 - P48
DOI: 10.1055/s-0032-1308814

Characterization of lymphoid follicles with red ring signs as first manifestation of early Crohn's disease by confocal laser endomicroscopy

E Krauss 1, A Agaimy 2, H Neumann 1, MF Neurath 1, J Mudter 1
  • 1Medizinische Klinik 1, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen
  • 2Institut für Pathologie, Universtität Erlangen-Nürnberg, Erlangen

Background and aims: Clinical observations suggest that the lymphoid follicles (LFs) may play a crucial role in the pathogenesis of inflammatory bowel disease (IBD), especially in Crohn's disease (CD), being sites of initial mucosal inflammation. The aim of this study was to compare the morphology of LFs in CD, ulcerative colitis (UC) and control patients using confocal laser endomicroscopy (CLE) in correlation to histological and immunohistochemical findings of targeted LFs biopsies.

Methods: 146 patients (46 patients in CD group, 32 in ulcerative colitis (UC) group, 1 patient with indeterminate colitis; 72 male, 74 female; median age 32.5 years, range 19–65 years) were enrolled in this prospective study when undergoing ileo-colonoscopy. To analyze the LFs, the standardized images from the terminal ileum throughout the colon were taken using white-light magnification video endoscopes. Targeted biopsies of LFs were analyzed using different immunohistochemistry stainings, additionally to haematoxylin and eosin. CLE was performed to compare the findings with histopathology.

Results: LFs were seen in all parts of the lower GI tract, but mostly in the terminal ileum and the cecum. 15 out of 17 patients with the first manifestation of CD or confirmation of disease in the further course showed LFs with endoscopically different pattern, as surrounded by red ring (red ring sign, RRS). LFs with RRS showed hypervascularization at the base of LF as well as in surrounding tissue as assessed by immunohistochemistry; these features were not seen in the control group. In some LFs with RRS beginning aphthous ulcers were seen, and also increased inflammatory activity above the LF. CD15 immunostaining demonstrated numerous granulocytes, which were not seen in the LFs without RRS. CLE of RRS showed abolished normal crypt architecture, crypt distortion, increased cellular infiltrate within the lamina propria, and dilated vessels.

Conclusion: LFs surrounded by red rings might represent an early sign of aphthous ulcers in early CD and, thus, be considered as early markers of first manifestation and flares in Crohn's disease.