Figure 2

Low power magnification of a section of UIP/IPF lung treated for the immunohistochemical localization of Wnt7B. Fibroblastic foci are easy to identify (large arrows), as are even small reactive sites (small arrows). Methylene blue counterstain. Bar = 600 μm. Figure2b, Section of UIP/IPF lung treated for the immunohistochemical localization of Wnt7B demonstrating the three categories designated for sizing and quantitation. Preliminary histopathologic evaluation of the slides determined that all reactive sites were confined to one of three characteristic types: epithelial + fibroblast + extracellular matrix (EF), subepithelial (SE, fibroblast + extracellular matrix), or interstitial (I, not adjacent to epithelial surfaces). Methylene blue counterstain. Bar = 100 μm. Figure2c-f, Serial sections of UIP/IPF lung treated for the immunohistochemical localization of Wnt7B (c, e) or Movat’s pentachrome (d, f) in airway (c, d) and alveolar (e. f) regions. The same fibroblastic foci (FF) stain clearly with both treatments. Methylene blue counterstain. Bar = 100 μm. Figure2g, Section of UIP/IPF lung treated for the immunohistochemical localization of Wnt7B demonstrating reactivity of the mesothelial surface (arrows) and the subjacent cells and thickened interstitium. Methylene blue counterstain. Bar = 100 μm.