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

PUCCI MOLINERIS, MELISA ; DÍAZ JIMENEZ, DAVID; CUETO RUA, EDUARDO; MEIER, DOMINIK; MUGLIA, CECILIA; CANZIANI, KARINA EVA; BALCARCE, NORMA; ALTAMIRANO, EUGENIA; LANDSKRON RAMOS, GAUBEN; FOSSATI, CARLOS; GUZMAN, LUCIANA; GARCÍA, MARCELA; DE LA FUENTE, MARJORIE; HERMOSO RAMELLO, MARCELA; DOCENA, GUILLERMO

Mar del Plata

Congreso; Reunión Conjunta SAIC-SAI-SAFE; 2016

SAIC-SAI-SAFE

Although colorectal polyps are mainly found in patients with carcinoma, juvenilepolyps are frequently found in pediatric patients with no history of tumordisease. The aim of this work was to characterize the cellular infiltrate ofsingle sessile colorectal polyps in children with rectal bleeding suspected tohave a food allergy.Children (44) with rectal bleeding were studied during the 2014-2015period. Colonoscopy was indicated in all patients, and the following studies werecarried out in excised polyps and surrounding tissue (control): H&Estaining, immunohistochemistry, confocal microscopy,quantitative  RT-PCR, cell proliferationand 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 ofatopy (70.8%), with high level of serum milk-specific IgE. SPT was negative in94.4% (17/18) patients. Unlike surrounding colonictissue, the polyp stroma showed a cell infiltrate with eosinophils andmononuclear cells, active germinal centers with proliferating and switchingcells, 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 allergicinflammatory infiltrate in colorectal polyps of atopic patients withIgE-producing cells, Th2 cells and active germinal centers. These findingssuggest a causal relationship between colorectal polyps and the atopiccondition of patients.