Journal: Annals of Neurology

Article Title: COVID ‐19‐Associated Critical Illness Myopathy with Direct Viral Effects

doi: 10.1002/ana.26318

Figure Lengend Snippet: Case 1. A vastus lateralis muscle biopsy showing severe myopathic changes with atrophic fibers, degenerative/necrotic fibers with loss of normal staining (A, hematoxylin and eosin; arrows ), increased adipose tissue (A,*), fibers with mitochondrial proliferation (B, Gomori trichrome staining; arrows ), vacuoles containing debris (C, Gomori trichrome staining; arrow ), and fibers with increased reactivity for NADH (D,*). Immunohistochemistry revealing focally scattered CD68+ macrophages (E), CD8+ T‐cells (F), MHC‐1 sarcolemmal and sarcoplasmic staining in necrotic and non‐necrotic fibers (G), occasional p62+ puncta/vacuoles (H, arrows ), and SARS‐CoV+ fibers containing strongly positive granules (I, arrows ). Electron microscopy demonstrating extensive loss of A bands with retained Z lines and I bands (J,*), virus‐like particles in necrotic fibers (K, arrows , with characteristic surface projections/spikes; an inset of the left arrowed area ), and degenerative fibers (L‐O, a series of magnifications focusing on a virus‐like particle, arrows ; L, with identifiable myofibrils,*; M, the rectangle in L; N, higher magnification of the arrowed area in M; O, higher magnification of the arrowed area in N), numerous abnormal mitochondria with electron‐dense granules (P–R), focal to extensive loss of cristae, crystalline inclusions (Q, arrow ), and virus‐like particles (R, arrow , with an inset of the arrowed area). Scale bars: 20 μm (A), 10 μm (B–I), 800 nm (J), 100 nm (K, N), 600 nm (L, P), 200 nm (M, Q), 50 nm (O), and 500 nm (R). NADH = nicotinamide adenine dinucleotide; SARS‐CoV = severe acute respiratory syndrome‐coronavirus.

Article Snippet: The following antibodies were used: p62/SQSTM1 (Progen Biotechnik; 1:100 dilution following antigen retrieval), LC3 (clone 5F10, Enzo; 1:200 dilution following antigen retrieval), and SARS‐CoV nucleoprotein (SARS‐CoV, Sino Biological; NB100‐56576, raised by a synthetic peptide corresponding to amino acids 399 to 411 [ADMDDFSRQLQNS‐C] of the human SARS coronavirus nucleocapsid protein; 1:5000 dilution following antigen retrieval).

Techniques: Staining, Immunohistochemistry, Electron Microscopy

Journal: Annals of Neurology

Article Title: COVID ‐19‐Associated Critical Illness Myopathy with Direct Viral Effects

doi: 10.1002/ana.26318

Figure Lengend Snippet: Case 2. A vastus lateralis muscle biopsy showing marked myopathic changes with vacuoles (A, loss of hematoxylin and eosin staining; B, lost or increased Gomori trichrome staining; arrows ), rubbed‐out centers on NADH staining with granular/vacuolar positivity preferentially at the periphery (C, arrows ), punctate immunostaining for p62 (D, arrows ) and LC3 (E, arrows ) in the fiber centers, focal MHC‐1 immunostaining (F), SARS‐CoV+ fibers containing strongly positive granules (G, arrows ), and electron microscopy findings of fibers with loss of A bands and retained Z lines (H–J, *), vacuoles containing granules/particles (H), virus‐like particles in the subsarcolemmal areas (I–K, a series of magnifications focusing on a virus‐like particle; J, the rectangle in I, with an inset of the arrowed virus‐like particle; K, the rectangle in J, containing the arrowed virus‐like particle), and disrupted myofibrils (L; M, the rectangle in L, containing the arrowed virus‐like particle), and abnormal mitochondria in an atrophic/degenerative fiber (N, with focally identifiable myofibrils and Z lines, *; O, the rectangle in L, containing abnormal mitochondria, *). Scale bars: 10 μm (A–G), 1 μm (H, I), 400 nm (J), 100 nm (K, M), 600 nm (L), 2 μm (N), and 200 nm (O). NADH = nicotinamide adenine dinucleotide; SARS‐CoV = severe acute respiratory syndrome‐coronavirus.

Article Snippet: The following antibodies were used: p62/SQSTM1 (Progen Biotechnik; 1:100 dilution following antigen retrieval), LC3 (clone 5F10, Enzo; 1:200 dilution following antigen retrieval), and SARS‐CoV nucleoprotein (SARS‐CoV, Sino Biological; NB100‐56576, raised by a synthetic peptide corresponding to amino acids 399 to 411 [ADMDDFSRQLQNS‐C] of the human SARS coronavirus nucleocapsid protein; 1:5000 dilution following antigen retrieval).

Techniques: Staining, Immunostaining, Electron Microscopy

Journal: Annals of Neurology

Article Title: COVID ‐19‐Associated Critical Illness Myopathy with Direct Viral Effects

doi: 10.1002/ana.26318

Figure Lengend Snippet: Case 3. A biopsy of the vastus lateralis muscle showing fibro‐adipose tissue with rare residual atrophic fibers (A, hematoxylin and eosin; arrows ; inset in A, ATPase 4.3 histochemical staining: negative atrophic fibers compared to the arrowheaded positive granules), occasional vacuoles containing muscle debris positive for myoglobin immunostaining (B, arrows ), focally scattered CD68+ macrophages (C) and CD8+ T‐cells (D), but negative SARS‐CoV immunostaining (E). Electron microscopy demonstrating abnormal mitochondria with focal degenerative changes (F; arrows , compared to a relatively preserved mitochondrion, arrowhead ). Scale bars: 20 μm (A), 10 μm (B–E), and 200 nm (F). SARS‐CoV = severe acute respiratory syndrome‐coronavirus.

Article Snippet: The following antibodies were used: p62/SQSTM1 (Progen Biotechnik; 1:100 dilution following antigen retrieval), LC3 (clone 5F10, Enzo; 1:200 dilution following antigen retrieval), and SARS‐CoV nucleoprotein (SARS‐CoV, Sino Biological; NB100‐56576, raised by a synthetic peptide corresponding to amino acids 399 to 411 [ADMDDFSRQLQNS‐C] of the human SARS coronavirus nucleocapsid protein; 1:5000 dilution following antigen retrieval).

Techniques: Staining, Immunostaining, Electron Microscopy