Short summary

Idiopathic inflammatory myopathies (IIMs) - also known as myositis - are chronic inflammatory muscle diseases characterized clinically by progressively muscle weakness and muscle fatigue, and histopathologically by inflammatory cell infiltrates in skeletal muscle. Besides involving the muscles, IIMs are characterized by multisystem involvement including heart affection, a significant cause of death in these patients. Autoantibodies are important biomarkers in IIMs and are increasingly recognized to be associated to different clinical manifestations. However, the potential role of MSAs in cardiac involvement in myositis has yet to be elucidated.

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Rationale

Purposes

• To measure MSAs and MAAs in a large cohort of patients with myositis and MAAs in a cohort of patients with systemic sclerosis
• To estimate the presence of various electrographic (ECG) abnormalities in a cohort of patients with myositis compared with a control group of patients with systemic sclerosis and a group of healthy controls
• To evaluate possible associations between ECG changes and clinical and laboratory variables, including MSAs/MAAs in patients with myositis compared with a group of patients with systemic sclerosis

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Description of the cohort

Myositis

Inclusion criteria:

Patients, age above or equal to 18 years old, diagnosed with PM/DM (ICD codes M33.1, M33.2, M33.9) according to the classification criteria by Peter and Bohan or IBM (ICD code G73.4c) according to Griggs criteria. Patients (n = 290) will be recruited from Sweden and Denmark

Systemic sclerosis

Inclusion criteria:

Patients, age above or equal to 18 years old, diagnosed with systemic sclerosis (ICD codes M34.0, M34.1, M34.8, M34.9) according to The 2013 Classification Criteria for Systemic Sclerosis.

Patients (n = 115) will be recruited from Odense University Hospital, Denmark

Data and biological material

• Blood samples
• Basic cardiovascular questionnaire concerning: medical conditions, current medication, heart symptoms and smoking habits (appendix 10)
• Body mass index (BMI)
• Systolic (S-BP) and diastolic blood pressure (D-BP)
• ECG
• Clinical data from MYODAN (Danish IIM Register) 

Collaborating researchers and departments

Faculty of Health Sciences, University of Southern Denmark

• Medical student Sine Søndergaard Korsholm

Department of Rheumatology, Odense University Hospital

• Associate Professor Louise Pyndt Diederichsen, MD, PhD
• John Bonde Knudsen, MD

Department of Dermatology, Odense University Hospital

• Lone Hvid, MD, PhD

Department of Cardiology, Odense University Hospital

• Associate Professor Axel Cosmus Pyndt Diederichsen, MD, PhD

Lupus and Vasculitis Clinic, Rigshospitalet, Copenhagen University Hospital

• Professor Søren Jacobsen, MD, DMSc

Department of Medicine, Rheumatology Unit, Karolinska University Hospital, Stockholm

• Professor Ingrid Lundberg, MD, PhD
• Maryam Dastmalchi, MD