Sudden Cardiac Death due to Coronary Artery Vasculitis in a Patient with Relapsing Polychondritis

Figure 2

Histology of auricular cartilage, and immunohistochemical staining for IgG4 plasma cells from second patient with RP at our institute. (a) High-power magnification of auricular cartilage showing damage to cartilage including cartilage eosinophilia, infiltration by small blood vessels, as well as lymphoplasmacytic infiltration. The asterisk indicates cartilage eosinophilia, and arrows indicate representative small blood vessels and area of lymphoplasmacytic infiltration (H&E, 200x). (b) High-power magnification showing presence of IgG4-positive plasma cells (brown staining) in auricular cartilage, with arrows indicating representative IgG4-positive plasma cells (immunohistochemical staining of IgG4-positive plasma cells, 400x). There were 216 IgG4 + plasma cells and 601 IgG + plasma cells, and the IgG4/IgG ratio was 36%.