CXCL13 immune deposits in the liver of HCV-infected patients. (A) Hematoxylin and eosin staining of liver biopsy from an MC patient. Note enlarged portal tract containing infiltrating inflammatory cells with follicle-like structure (Ai; magnification, 10×/0.25). Phenotypic characterization of inflammatory cells is depicted in panels Aii to Aiv. Magnification, 20×/0.40. B cells, T cells, and monocytes/macrophages were studied by indirect immunohistochemistry using mouse anti-CD3, anti-CD20, and anti-CD68 antibodies and revealed with antimouse immunoglobulins conjugated with alkaline phosphatase in sections adjacent to panel Ai. All 3 cell populations are abundantly present within inflamed portal tract. (B) Follicle-like appearance of CXCL13 protein restricted to a portal tract structure on a section adjacent to panel A. Magnification, 20×/0.40. (C) CXCL13 deposits are homogeneously distributed in portal tract and in hepatic sinusoids. Magnification, 20×/0.40. (D) Higher magnification (63×/0.75) demonstrates that CXCL13 is present on intrasinusoidal inflammatory cells and along sinusoidal walls.