The role of immune modulatory CD163+ macrophages and FOXP3+ T regulatory lymphocytes in ulcerative colitis

Abstract

Abstract Background Recently, research work was intensified to explore the role of the immune microenvironment in different diseases. The inflammatory Bowel Disease- Distribution, Chronicity, Activity score (IBD-DCA) is now accepted as a practical reproducible tool for assessment of the histologic inflammatory burden and histologic mucosal healing in ulcerative colitis (UC) endoscopic biopsies. The particular contribution of immune modulatory CD 163+ macrophages and FOXP3+T regulatory lymphocytes (T-regs), and their implication in UC pathogenesis and course are still not clearly elaborated. Correlation between these attributes and the histologic indices would offer valuable insights that could help tailor the management plan on a personalized medicine protocols level, in addition to paving roads to new therapeutic target modalities. Aim of the study Evaluate the role of immune modulatory CD163+ macrophages and FOXP3+ T regulatory lymphocytes in ulcerative colitis and correlate their immunohistochemical expression with the pathological parameters of Inflammatory Bowel Disease- Distribution, Chronicity, Activity score (IBD-DCA score). Materials and methods Paraffin-embedded tissue sections from 60 cases of endoscopic colonic biopsies diagnosed as ulcerative colitis were immunohistochemically studied for CD163 and FOXP3 expression and graded semi-quantitively. Furthermore, histopathological features were evaluated according to IBD-DCA score and correlated with CD163 and FOXP3 expression for statistical analysis. Results CD163+ macrophages and FOXP3+ T-regs were demonstrated in 100% (60/60) and 78% (47/60) respectively of the lamina propria of ulcerative colitis cases. Significant correlation with activity (A) parameter of DCA-score and architectural distortion of detailed chronicity parameter for both markers was detected. Additionally, CD163 immuno-expression showed significant correlation with detailed activity parameters while FOXP3 presented a significant correlation with the chronicity parameter of DCA score. Conclusion The immune modulatory CD 163+ macrophages and FOXP3+T-regs represent key players in mucosal tissue inflammation, disease activity and chronicity in UC. This could offer new therapeutic modalities targeting the players of the immune microenvironment that should be deeply investigated in future studies.