Kaposi sarcoma shows diffuse staining for CCR8 and I-309.

Biopsies of Kaposi sarcoma were stained for multiple antigens as detailed in “Materials and methods.” Shown is a Kaposi sarcoma patch stained with goat polyclonal anti-CCR8 (A), anti-I-309 (B), anti-vWF (C), murine monoclonal anti-CCR8 (Mab > CCR8; D), anti-CD-68 (E), anti-α-actin (F), secondary antibody alone (Control, G), and isotype control IgG1 (H). The Kaposi sarcoma spindle cells stain intensely for CCR8 with both the polyclonal and monoclonal antibodies (A,D). The spindle cells also stain diffusely for vWF and CD-68 (C,E). Pericytes in small vessels stain for α-actin (F). There is no staining when the primary antibody is omitted (G), and only a trace staining with the mouse IgG1 isotype control (H). (DAB-peroxidase, hematoxylin counterstain, original magnification × 200).