P053. Regulatory CD25+FoxP3+ T cells in the intestinal mucosa of patients with inflammatory bowel disease. Corticoids treatment effect
A. Carrasco1, F. Fernandez Bañares1, M. Rosinach1, C. Loras1, M. Aceituno1, E. Pedrosa2, J. Mañe2, V. Loren2, J.M. Viver1, M. Esteve1
1Hospital Universitari MútuaTerrassa, Terrassa, Spain; 2Institut de Recerca Germans Trias i Pujol, Badalona, Spain
Background: A decrease of regulatory CD3+CD4+CD25+FoxP3+ T cells (Treg) in peripheral blood has been detected in patients with Inflammatory Bowel Disease (IBD), and an increase of these same cells is associated to a good response to rescue treatments (infliximab or leukocytapheresis) in steroid refractory patients. In intestinal mucosa, this subpopulation has been assessed only by PCR and immunohistochemical methods, and there is not any information by using flow cytometry. Aim: To analyze Treg number in peripherial blood and intestinal mucosa in IBD patients and to analyse the effect of corticosteroid treatment upon this lymphocyte subpopulation.
Methods: 7 healthy controls, 4 Ulcerative Colitis (UC) and 20 Crohn's disease (CD) patients were included. The majority of CD patients were included at diagnosis (early CD). Samples were taken from patients with active CD and after 35 weeks of corticosteroid therapy. Lymphocytes were isolated and analyzed by flow cytometry. Statistical analysis for paired and unpaired data was performed.
Results: Expressed as median [IQ]. Differences in Treg number were not detected between IBD and healthy controls in blood. A significant increase of Treg was detected in the intestinal mucosa of UC patients (10.89 [8.3311.52]) compared to controls (5.62 [3.277.40]), p = 0.006. No differences were detected between CD and controls. Treatment with corticosteroids in CD patients caused a decrease of Treg in peripheral blood (Pre: 4.74 [2.2210.11]; Post: 3.62 [1.9410.25]; p = 0.04) as well as in intestinal mucosa (Pre: 12.83 [4.7121.06]; Post: 6.19 [2.3612.69]; p = 0.03). This decrease was independent of their response to the corticosteroid treatment.
Conclusions: Contrary to previously reported data, a decrease of Treg cells has not been detected either in blood or in intestinal mucosa of CD. These differences with other studies might be due to the type of population included (early versus late CD). Treatment with corticosteroids causes a decrease of Treg cells in blood as well as in intestinal mucosa being different from that caused by rescue treatments.
Financial support was received from the Ministerio de Ciencia e Innovación (project BFU-201019888)