Figure 2

Immunofluorescent double-staining of B and plasma cells expressing receptors for B cell–activating factor of the tumour necrosis factor family in the muscle mononuclear cell infiltrate from a representative anti-Ro52/anti-60-positive patient with polymyositis. Immunofluorescence staining for plasma cell marker CD138 (red) and B cell maturation antigen (BCMA) (green) (A) in a tissue biopsy section from the same patient as in Figure 1 (original magnification, ×200) with details (B) of staining for CD138, BCMA, 4′,6-diamidino-2-phenylindole (DAPI) and an overlay created with the confocal microscope (original magnification, ×600). Scattered CD19-positive cells were also present remote from the CD138-positive cells and were positive for BAFF-R (C) as expressed in details of CD19 (red), BAFF-R (green), DAPI (blue) and an overlay created with the confocal microscope (original magnification, ×600).