Abstract
Background: Inflammatory bowel disease (IBD) results particularly from aberrance of CD4+ helper and regulatory T cells and is histopathologically chronic active enterocolitis with features reflecting both activity and chronicity of mucosal inflammation. The exact immunologic-histologic correlation is not understood.
Methods: We studied the correlation between colonic mucosal CD4+ T cell subsets (Th1, Th2, Th17, Th22, and Treg) and mucosal histologic changes in ulcerative colitis (UC) and Crohn's disease (CD). CD4+ T cell subtyping and enumeration were achieved by flow cytometry. Histologic features were categorized and semi-quantitated using three validated histological scoring schemes (ECAP, RHI, and D'Haens). Correlations between prevalence (%) of CD4+ T cell subsets and histologic scores were analyzed.
Results: Treg cells were correlated with ECAP category A (activity) as well as RHI scores. Treg was particularly increased in mucosa with severe neutrophilic infiltration in cryptal/surface epithelium and in lamina propria, and with basal plasmacytosis. Th17 cells were also increased in cases with extensive neutrophil infiltrate in lamina propria, whereas RORc+ cells were increased in cases with severe lymphoplasmacytic infiltration in lamina propria. In both UC and CD, the mucosa with marked crypt architectural alteration had increased IL-22+ and Th22 cells. UC with Paneth cell metaplasia had higher Th17 cells. CD with granuloma had increased IL-22+ and IL-22+IFN-γ+ cells.
Conclusions: Treg appears to be associated with the overall severity of IBD histopathology, particularly with active inflammation. Th17 is also associated with activity. Whereas IL-22+ cells are associated with chronicity and granuloma formation in CD.
Original language | English |
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Journal | Journal of Crohn's & Colitis |
Early online date | 20 Aug 2018 |
DOIs | |
Publication status | Published - 2018 |