MSAs are rarely found outside idiopathic inflammatory myopathies and help define clinical subtypes, complications, and expected treatment response

Autoantibody
Subtype/FeaturesTreatmentPrognosis
Anti-Jo-1
Antisynthetase syndrome, ILD, arthritis, mechanic’s handsEarly immunosuppression; treat ILD aggressivelyChronic ILD common; better outcomes with early therapy
Anti-PL-7 / PL-12 / EJ / OJ / KS / Zo / Ha
Antisynthetase variants; ILD often dominantAggressive ILD management; combination therapyILD severity varies; some forms more severe
Anti-Mi-2
Classic dermatomyositis with strong skin diseaseResponds well to steroids and standard immunosuppressantsLow cancer risk
Anti-MDA5
Amyopathic DM; rapidly progressive ILD; skin ulcersImmediate, aggressive multi-agent therapyHigh mortality risk due to ILD
Anti-TIF1-gamma
Dermatomyositis; strongest link to cancerThorough cancer screeningHigh malignancy risk in adults
Anti-NXP2
Dermatomyositis; calcinosis; increased cancer riskCancer screening; long-term calcinosis managementCalcinosis may be severe; malignancy risk elevated
Anti-SAE
Dermatomyositis with prominent skin diseaseScreen for malignancy; treat skin and muscle diseaseVariable; possible cancer association
Anti-SRP
Immune-mediated necrotizing myopathy (IMNM)Often requires IVIG plus aggressive immunosuppressionCan be difficult to treat; chronic weakness common
Anti-HMGCR
Statin-associated or statin-independent IMNMAvoid statins permanently; steroids + IVIGChronic but treatable; improves with early therapy
Anti-cN1A (NT5c1A)
Inclusion body myositisIBM is treatment-resistant; focus on rehabSlowly progressive; limited response to therapy

Disclaimer: Information provided on this website is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with any questions you may have regarding a medical condition.