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The following is a summary of “Patients with anti-PM/Scl-positive and idiopathic inflammatory myopathy resemble anti-synthetase syndrome,” published in the February 2025 issue of Advances in Rheumatology by Barbosa and Shinjo. 

Researchers conducted a retrospective study to analyze the relevance of anti-PM/Scl autoantibody associated with an overlap between polymyositis (PM) and systemic sclerosis (SSc) in patients with idiopathic inflammatory myopathies (IIMs) without SSc. 

They conducted a single-center retrospective cohort study (2004–2024) on 93 adults with IIMs (66 dermatomyositis, 27 PM – EULAR/ACR 2017) without SSc: 16 anti-PM-Scl(+) and 77 anti-PM-Scl(-). They excluded patients with other IIMs, cancer-associated myositis, overlap myositis (including SSc), and those with other myositis-specific or myositis-associated autoantibodies. 

The results showed comparable median age, sex distribution, and follow-up duration between anti-PM-Scl(+) and anti-PM-Scl(-) groups. Lung involvement, joint involvement, mechanics’ hand, hiker’s feet, and Raynaud’s were higher in anti-PM-Scl(+) (all P < 0.05), while facial rash and V-neck sign were lower (P < 0.05). Disease relapse (68.8% vs. 33.8%), disease activity (50.0% vs 24.7%), and immunosuppressant use (methotrexate or azathioprine) were higher in anti-PM-Scl(+) (P < 0.05). Severe infection and death rates were comparable. 

Investigators observed anti-PM-Scl positivity in 17.2% of patients who had clinical features resembling anti-synthetase syndrome with higher disease relapse and activity rates. 

Source: advancesinrheumatology.biomedcentral.com/articles/10.1186/s42358-025-00441-y