P051 Chemokines CXCL17, CCL20, and the receptor CXCR5 are overexpressed in the colonic mucosa from patients with active ulcerative colitis: CXCL17 is a potential marker of histological remission
J. Yamamoto-Furusho*1, E. Iturriaga-Goyon2, G. Fonseca-Camarillo1
1IBD Clinic, Instituto Nacional de Ciencias Medicas y Nutricion, Gastroenterology, Mexico, Mexico, 2Instituto Nacional de Ciencias Medicas y Nutricion, Gastroenterology, Mexico, Mexico
Patients with ulcerative colitis (UC) have shown an important production of chemokines. Chemokines CXCL17, CCL20, and the receptor CXCR5 have emerged as the most important regulators of mucosal immunity and leukocyte trafficking during inflammation and, therefore, have been implicated in the pathogenesis of UC. The aim of the present study was to determine the gene expression of CXCL17, CCL20, and CXCR5 in colonic tissue from patients with UC and controls, as well as its association with clinical outcomes.
We included 120 patients with confirmed diagnosis of UC and 60 controls without endoscopic evidence of any type of colitis or neoplasia. An independent GI pathologist reviewed slides and classified UC histologically as being either active or inactive. Active disease was defined histologically by the presence of lymphoplasmocytic and neutrophilic infiltration in the lamina propia, as well as cryptitis, crypt abscesses, and crypt distorsion. Histological remission was defined by lack of chronic inflammation, crypt distortion, cryptitis, and crypt abscess. The relative quantification of the gene expression was performed by real-time polymerase chain reaction (PCR) with specific primers for CXCL17, CCL20, and CXCR5, and a housekeeping gene GAPDH was used for normalisation purposes and quality controls. Descriptive statistics were used as means and standard deviations. Kruskal–Wallis tests was used to test differences amongst groups, and Chi-square to assess the association between chemokine gene expression and clinical features. The odds ratio (OR) was used for evaluating the association. Statistical analysis was performed using the programme SPSS V17. Statistical significance was considered when p-value was < 0.05.
The gene expression of CXCL17, CCL20, and CXCR5 were increased in patients with active UC, as compared with normal controls without inflammation (p = 0.003, p = 0.001 y p = 0.008), as well as UC in remission (p = 0.01, p = 0.007 y p = 0.0001). No significant differences were found between patients UC in remission and normal controls. The low expression of CXCL17 gene was associated significantly with histological remission (p = 0.04, RM = 7.8, CI 95%: 1.13–75.6).
The gene expression of CXCL17, CCL20, and CXCR5 were up regulated in active UC. The gene CXCL17 could have a potential marker of histological remission in patients with UC. These chemokines genes might have a potential role in the inflammation in patients with UC.