Routine and immunohistochemical stainings of liver biopsies. (A) Hematoxylin-eosin stain shows massive infiltration of portal tract (asterisk) and sinusoids by mononuclear cells. (B) Hematoxylin-eosin stain of specimen from patient D reveals a blank appearance of the portal tract. The numerous macrophages cannot be recognized. (C) CD68 stain shows numerous macrophages as large, irregularly shaped CD68⁺ cells, localized both in the portal tract (asterisk) and sinusoids. (D) Detail of CD68 stain shown in panel C shows active phagocytosis by CD68⁺ macrophages of lymphocytes (arrowhead), erythrocytes (short arrow), and polynuclear cells (long arrow). (E) TNF-α stain shows TNF-α production by macrophages, identified as large irregularly shaped cells in portal tracts and sinusoids. (F) IL-6 stain shows IL-6 production by macrophages, identified as large irregularly shaped cells in portal tracts and sinusoids. (G) CD8 stain shows numerous CD8⁺ lymphocytes as small, round CD8⁺ cells, with a small rim of cytoplasm. (H) IFN-γ stain shows IFN-γ production by lymphocytes, identified as small, round cells with a small rim of cytoplasm. The microscope was a Leitz Laborlux 5 (Wetzlar, Germany); objective lenses × 2.5, × 10, × 40, and × 100. The digital camera was a Nikon Coolpix 950, and image processing was done with Adobe Photoshop CS.