ABOUT AUTOIMMUNE MYOSITIS

A chronic, progressive disease
with autoantibodies as a key driver1

Autoimmune myositis (AIM) is a rare, heterogenous disease spectrum encompassing
a range of distinct subtypes, each with varied clinical features and complex underlying disease mechanisms.1,2
 

With autoantibodies as a key driver, AIM leads to muscle damage and weakness, and can affect multiple organ systems, which may result in a substantial impact on patients' quality of life.1,3

What is AIM?

AIM is a rare autoimmune rheumatic disease spectrum, encompassing heterogeneous subtypes with diverse clinical presentations.3,4

 

A typical feature is progressive, symmetrical weakness of the proximal muscles. As a chronic, progressive condition with both muscular and extramuscular involvement, AIM can lead to loss of independence and a substantial impact on quality of life.2,5

Take a deeper look at AIM
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AIM is comprised of subtypes with diverse manifestations and clinical concerns2,3

Muscle weakness is usually the common clinical manifestation, but other organs are often affected to varying degrees across subtypes.2,3

Simple cross-section diagram of the skin with 3 hair follicles and inflamed skin tissue.
Dermatomyositis (DM)
Collection of icons representing a muscle, lungs, joints, and skin.
Antisynthetase syndrome (ASyS)
Simplified diagram of a muscle structure.
Immune-mediated necrotizing myopathy (IMNM)
Simplified diagram of a muscle structure with diagnonal line across it, placed next to warning sign over 3 antibody icons.
Polymyositis (PM)
Collection of icons representing lungs, stomach, heart, joints, and skin.
Overlap myositis (OM)
Icon of a person walking with wavy lines around the legs.
Inclusion body myositis (IBM)
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CLINICAL MAINFESTATIONS

How AIM presents and progresses

AIM comprises a spectrum of distinct subtypes with diverse clinical manifestations. While skeletal muscle weakness is the hallmark, the disease can also affect the skin, lungs, gastrointestinal tract, joints, and heart. Key complications of concern include associated malignancy, interstitial lung disease, skin involvement, myocarditis, and dysphagia.1,3

Learn about the clinical manifestations of AIM

Continue exploring AIM

Learn more about the role of autoantibodies, the burden of disease, and current and emerging treatments. 

Role of autoantibodies

Autoantibodies are a hallmark feature of AIM.6

Autoantibodies and AIM
Burden of disease

AIM can reshape the lives of patients and those around them.5

The burden of AIM
Current treatments

There remains an unmet need for effective and well-tolerated treatments for AIM.7

Current treatments for AIM

Abbreviations:
ADM, amyopathic dermatomyositis; AIM, autoimmune myositis; ASyS, antisynthetase syndrome; DM, dermatomyositis; HMGCR, 3-hydroxy-3-methylglutaryl-coenzyme A reductase; IBM, inclusion body myositis; IIM, idiopathic inflammatory myopathy; ILD, interstitial lung disease; IMNM, immune-mediated necrotizing myopathy; OM, overlap myositis; PM, polymyositis.

 

References:
1. Diomedi M, et al. Clin Exp Rheumatol. 2026;44(2):167–177; 2. Oldroyd A, et al. Clin Med (Lond). 2017;17(4):322–328; 3. Paik J, et al. Rheumatol. 2025;64:3288–3302; 4. Giannini M ,et al. Clin Exp Rheumatol. 2025;43:178–183; 5. Oldroyd A, et al. BMC Rheumatol. 2020;4:47; 6. Groener M, et al. Front Immunol. 2025;16:1581323; 7. Natour A and Kivity S. Rambam Maimonides Med J. 2023;14(2):e0008.