Characterization of the Th2-signature of colorectal polyps in atopic children.

NANFITO G; DÍAZ JIMENEZ D; CUETO RÚA E; MEIER, D; MUGLIA C.I.; CANZIANI, K.; GUZMAN, L; GARCIA, M; PUCCI MOLINERIS, M.; DE LA FUENTE M; BALCARCE, N; HERMOSO RAMELLO M; DOCENA, G.; ALTAMIRANO E; LANDSKRON RAMOS G; FOSSATI, C

Congreso; SAIC.SAI.SAFE 2016; 2016

Although colorectal polyps are mainly found in patients with carcinoma, juvenile polyps are frequently found in pediatric patients with no history of tumor disease. The aim of this work was to characterize the cellular infiltrate of single sessile colorectal polyps in children with rectal bleeding suspected to have a food allergy.Children (44) with rectal bleeding were studied during the 2014-2015 period. Colonoscopy was indicated in all patients, and the following studies were carried out in excised polyps and surrounding tissue (control): H&E staining, immunohistochemistry, confocal microscopy, quantitative RT-PCR, cell proliferation and ELISA. Besides, IgE analysis was carried out by skin prick test (SPT) and serology (ELISA). Polyps were found in 18 out of 44 patients (40.9%), who presented a personal and/or family clinical history of atopy (70.8%), with high level of serum milk-specific IgE. SPT was negative in 94.4% (17/18) patients. Unlike surrounding colonic tissue, the polyp stroma showed a cell infiltrate with eosinophils and mononuclear cells, active germinal centers with proliferating and switching cells, IgE-producing plasma cells, significant high levels of Th2 cytokines (IL-5 and IL-13) and eotaxin-3, and low levels of IFN-γ and IL-17 . Polyps had milk-specific T cells, TSLP+ cells, ST2+ cells and IL-33-producing cells.In conclusion, we found an allergic inflammatory infiltrate in colorectal polyps of atopic patients with IgE-producing cells, Th2 cells and active germinal centers. These findings suggest a causal relationship between colorectal polyps and the atopic condition of patients.