Distribution of E-cadherin in the gastrointestinal mucosa. Pinch biopsies from the colon of 11 HIV-1 negative and 7 chronically infected HIV-1 subjects with progressive disease not on ART were obtained and stained for E-cadherin by immunohistochemistry (brown) and counterstained with hematoxylin. (A) Four representative immunohistochemical stainings from the intestine of HIV-negative and chronic untreated HIV-1⁺ subjects along with staining with an isotype control. E-cadherin in normal human colon is primarily localized to the mucosal epithelium and epithelial basement membrane, whereas redistribution of E-cadherin is visible in the lamina propria of HIV-1–infected subjects. Quantitation of E-cadherin staining was performed on 5 representative regions of the lamina propria from each section. The horizontal lines at each variable indicate the mean (B). The area of positive E-cadherin staining in the lamina propria was quantitated and found to be significantly higher in subjects with HIV-1 infection than in HIV-1–uninfected subjects (P = .002).