Fig. 2
From: What should we expect when two myositis-specific antibodies coexist in a patient
Muscle biopsy from patient 1 and patient 3. Patient 1: A hematoxylin and eosin (HE) staining showing no necrotic or regenerating myofibers. B Major histocompatibility complex 1 (MHC-I) immunostaining (brown) is upregulated in both the sarcolemma and sarcoplasm of myofibers. C Membrane attack complex (MAC) immunostaining showed deposition of MAC on scattered myofibers. Patient 3: D HE staining showing many necrotic and regenerative muscle fibers without endomysia inflammatory infiltrates. E MHC-I is upregulated in both the sarcolemma and sarcoplasm. F Deposition of MAC on non-necrotic myofibers (bars 50 μm, A–F)