Myositis autoantibodies.

PURPOSE OF REVIEW: To review recent advances in our understanding of autoantibodies associated with dermatomyositis and the autoimmune necrotizing myopathies.

RECENT FINDINGS: Autoantibodies preferentially associated with dermatomyositis include those recognizing Mi-2, MDA5, TIF1γ, and NXP-2. Each of these is associated with a distinct clinical phenotype. Autoantibodies found in patients with autoimmune necrotizing myopathies recognize signal recognition particle and 3-hydroxy-3-methylglutaryl-coenzime A reductase (HMG-CoA) reductase. The latter are found in patients with statin-associated autoimmune muscle disease.

SUMMARY: As these are helpful both diagnostically and prognostically, a rheumatologist should be familiar with autoantibodies found in patients with dermatomyositis and the autoimmune necrotizing myopathies.