Figure 2.

Vimentin immunohistochemical analysis. Nine paired FFPE samples of strictured and non‐strictured intestinal tissue from patients with Crohn's disease (CD) were stained for vimentin. Image J was used to analyse the area (in pixels) positive for vimentin as a proportion of the total area (in pixels) assessed within 2 randomly selected regions of 100 consecutive surface epithelial cells and 3 randomly selected whole crypts in each section of 9 sample pairs. Panel A shows the paired percentage values of area positive for vimentin staining in non‐strictured and strictured samples. Panel B shows the mean percentage of area positive for vimentin staining in strictured and non‐strictured tissue. There is a significant increase in the percentage of area positively stained for vimentin in the strictured specimens compared to the non‐strictured specimens (P = 0.003). Bars represent standard error of the mean (SEM). **P < 0.01. Panels C‐H, immunohistochemical staining demonstrating specific positivity for vimentin within the lamina propria and submucosa of non‐strictured (C, ×0.6; D, ×20; E, ×20) and strictured (F, ×0.6; G, ×20; H, ×20) intestinal sections from patients with CD. Panels D and E show the areas of surface epithelium and crypts highlighted in panel C by the black rectangle, respectively, at a higher magnification. Panels G and H show the areas of surface epithelium and crypts highlighted in panel F by the black rectangle, respectively, at a higher magnification. Both the surface epithelium and crypt epithelium show higher positive staining in the strictured specimens than in the non‐strictured specimens