Table 2. Clinical, Laboratory, Imaging, and Pathological Features of Patients With Myopathy.

Patient No.	Clinical Findings	Onset to Maximum Severity	CK	Electromyography	Magnetic Resonance Imaging	Histopathological Findings	Antibodies	Connective Tissue Markers	ESR/CRP
1	Extraocular, bulbar, and proximal limb girdle weakness	3 wk	3.8 Times ULN	Proximal myopathy with fibrillation potentials, repetitive nerve stimulation normal	Increased T2-weighted signal and deep paraspinal musculature enhancement	Necrotizing myopathy (Figure, A)	HMGCR, SRP, PNP, and AChR antibody negative, striated muscle antibody 1:61440, anti–PM/Scl antibody positive (36 U)	ANA 0.2, SSA, SSB, Sm, RNP, Scl-70, Jo-1 negative	ESR 20 mm/h, CRP 3.9 mg/L
2	Mild proximal shoulder weakness	9 d	21 Times ULN	Proximal myopathy without fibrillation potentials, length-dependent peripheral neuropathy	NA	Myopathy: 3 necrotic fibers, many ring and lobulated fibers on oxidative enzyme staining (Figure, B)	HMGCR negative, PNP and AChR antibody negative	ANA 0.5	NA

Abbreviations: AChR, acetylcholine receptor; ANA, antinuclear antigen; CK, creatine kinase; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; HMGCR, 3-hydroxy-3-methylglutaryl–coenzyme A reductase; Jo-1, histidyl tRNA synthetase; NA, not applicable; PM/Scl, anti-exosome; PNP, paraneoplastic; RNP, ribonucleoprotein; Scl 70, anti–topoisomerase I; Sm, Smith; SRP, signal recognition particle; SSA, Sjögren syndrome–related antigen A; SSB, Sjögren syndrome–related antigen B; ULN, upper limit of normal.

SI conversion factor: To convert C-reactive protein level to nanomoles per liter, multiply by 9.524.