P052. Interleukin 10 (IL10) expression and distribution pattern in healthy and inflamed bowel. Relationship with steroid response in Crohn's disease (CD)
A. Carrasco, F. Fernández-Bañares, C. Loras, E. Pedrosa, M. Aceituno, M. Rosinach, R. Temiño, M. Forné, E. Sainz, X. Andújar, M. Esteve, Hospital Universitari Mútua Terrassa. UB, Gastroenterology, Terrassa, Spain
Interleukin-10 (IL-10) is expressed by many cell types of the innate and adaptive immune system. Its effect depends on the cell type, where it is produced and the time and location of release. IL-10 distribution in the intestine is not well known due to the methodological difficulty of cytokine staining in human biopsies.
Aims: To evaluate the distribution and intensity of production of IL-10: (1) in healthy and inflamed intestine and (2) in Crohn's disease (CD) in relation to the corticosteroid response.
26 patients with intestinal inflammation [16 Crohn's disease (CD), 6 ulcerative colitis (UC) and 4 infectious colitis (IC)] and 10 healthy controls were included. Based on the steroid response, CD patients were classified as responders (steroid sensitive) and non-responders (steroid dependent and refractory). Samples in healthy controls were taken from ileum, left and right colon, whereas in patients samples were taken from inflamed areas. The protein expression of IL-10 was evaluated by immunofluorescence and the images obtained were processed with the ImageJ software [area (A) and mean fluorescence intensity (FI)]. We evaluated the distribution patterns and the cell type morphology. Nonparametric tests were used to compare IL-10 values between groups.
No significant differences in the IL-10 production were found between ileum, right and left colon in the healthy intestine (A: p = 0.589; IF: p = 0.513).
No significant differences were neither found between controls and the different conditions with intestinal inflammation (A: p = 0.869; IF: p = 0.366). In CD there were no significant differences between steroid responders and non-responders (A: p = 0.913; IF: p = 0.913) In both healthy and inflamed intestine the IL-10 was distributed making a subepithelial band or making cell clusters - predominantly of dendritic cells - in the lamina propria. No differences in the IL-10 distribution pattern were found depending on the location in the healthy intestine (ileum or colon), nor depending on the steroid response in CD.
The good IL-10 staining achieved by immunofluorescence reveals that this anti-inflammatory citokine is always present in along the intestine and regardless of health or disease status. The IL-10 disposition as a subepithelial band suggests an important role in defense against luminal antigens.