Idiopathic inflammatory myopathies: pathogenic mechanisms of muscle weakness

Skeletal Muscle

Table 2 Some of the important autoantibodies reported in inflammatory myopathies

Autoantibodies	Disease	Association	References
Anti-tRNA synthetases¹ (Anti-Jo; against histidyl tRNA synthetase)	More common in PM than DM	Interstitial lung disease	[63–65]
Anti-chromodomain helicase DNA binding proteins (anti-Mi2)	DM	Cutaneous lesions	[3, 66, 67]
Anti-MDA5/Anti-CADM-140	DM	Mucocutaneous lesions; severe lung disease minimal muscle involvement	[68–70]
Anti-TIF1γ²	DM	Malignancy	[71–73]
Anti-nuclear matrix protein (NXP)-2/anti-MJ	Mostly juvenile DM	Joint contractures; calcinosis	[74]
Anti-SAE³	DM	Skin and muscle manifestations	[75]
Anti-signal recognition particle	NM, PM	Degenerating and regenerating muscle fibers and possible cardiac involvement	[76–79]
Anti-HMG-CoA reductase⁴	Statin associated myopathy	Treatment with cholesterol lowering drugs	[80, 81]

PM Polymyositis, DM Dermatomyositis, NM Necrotizing myopathy.
¹Additional antisynthetase antibodies found in myositis are targeted against threonyl-tRNA synthetase (PL-7); alanyl-tRNA synthetase (PL-12); isoleucyl-tRNA synthetase (OJ); glycyl-tRNA synthetase (EJ); asparaginyl-tRNA synthetase (KS).
²TIF1γ: Transcription intermediary factor 1γ.
³SAE: Small ubiquitin like modifier activating enzyme.
⁴HMG-CoA reductase: 3-hydroxy-3-methylglutaryl-coenzymeA reductase.

ISSN: 2044-5040