What are the clinical features of Anti-DM5 (Dermyositis-specific autoantibody 5)-associated idiopathic inflammatory myopathy, including skin and systemic manifestations?

From the Guidelines

Anti-DM5 (Dermyositis-specific autoantibody 5)-associated idiopathic inflammatory myopathy is characterized by aggressive interstitial lung disease (ILD), particularly in Asian populations, and is associated with a distinct set of clinical features, including skin and systemic manifestations. The clinical features of Anti-DM5-associated idiopathic inflammatory myopathy include:

• Aggressive ILD, which can be rapidly progressive and life-threatening 1
• Skin manifestations, such as photosensitive rash, although the specific skin features associated with Anti-DM5 are not well-defined in the provided evidence
• Systemic manifestations, including arthralgia or arthritis, Raynaud's phenomenon, fever, weight loss, and dysphagia due to esophageal involvement, although these are not exclusively associated with Anti-DM5 1
• Increased risk of malignancy, especially within the first few years after diagnosis, although this is more commonly associated with other autoantibodies, such as anti-p155/140 1 The presence of Anti-DM5 antibodies is particularly associated with an increased risk of aggressive ILD, which can be life-threatening, making early diagnosis and treatment essential to improve morbidity, mortality, and quality of life outcomes. Treatment approaches for Anti-DM5-associated idiopathic inflammatory myopathy may involve high-dose corticosteroids, immunosuppressive therapy, and other disease-modifying antirheumatic drugs (DMARDs), although the specific treatment recommendations are not well-defined in the provided evidence 1. Some key points to consider in the management of patients with Anti-DM5-associated idiopathic inflammatory myopathy include:
• Early diagnosis and treatment of ILD to prevent progression and improve outcomes
• Aggressive immunosuppressive therapy to control disease activity and prevent malignancy
• Regular cancer screening to detect malignancy early, especially within the first few years after diagnosis
• Multidisciplinary care, including physiotherapy and specialist nursing, to manage systemic manifestations and improve quality of life.

From the Research

Clinical Features of Anti-DM5-associated Idiopathic Inflammatory Myopathy

The clinical features of Anti-DM5 (Dermyositis-specific autoantibody 5)-associated idiopathic inflammatory myopathy include:

• Skin manifestations such as photosensitive dermatitis, heliotrope rash, Gottron's papules, and nailfold changes 2
• Cutaneous manifestations like skin ulcerations, palmar papules (inverse Gottron), diffuse hair loss, panniculitis, and oral pain and/or ulcers are sometimes associated with anti-melanoma differentiation-associated gene 5 product (MDA5) antibody 3
• Systemic manifestations including progressive proximal muscle weakness, dysphagia, and hyperpigmented rash 4

Specific Autoantibody Associations

Specific autoantibodies are associated with distinct clinical features, such as:

• Anti-Mi-2 antibody is associated with classic features of DM, including heliotrope rash, Gottron's papules, the V-neck sign, the shawl sign, cuticular overgrowth, and photosensitivity 3
• Anti-transcriptional intermediary factor 1 gamma (TIF1γ)-positive patients are associated with diffuse photoerythema, including "dusky red face" 3
• Anti-MDA5 antibody is associated with skin ulcerations, palmar papules (inverse Gottron), diffuse hair loss, panniculitis, and oral pain and/or ulcers 3, 5

Double-positive Anti-MDA5 and Anti-aminoacyl-tRNA Synthetase Antibody Presentation

In cases of double-positive anti-MDA5 and anti-aminoacyl-tRNA synthetase antibody presentation:

• Hallmark cutaneous manifestations, including Gottron's sign, heliotrope rash, mechanic's hand, and skin ulcers are common 6
• Radiological characteristics such as NSIP with OP overlap, consolidation, ground-glass attenuation, traction bronchiectasis, and intralobular reticulation are also common 6