idiopathic inflammatory myopathy Myositis
Conditions
Interventions
None listed
Sponsors
Amsterdam UMC
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: - Adult patients (18-80 years) with IIM, according to the diagnostic criteria and the presence of the following antibodies. o IMNM with anti-SRP antibodies o IMNM with anti-HMGCR antibodies o IMNM without MSA (seronegative) o (Dermato)myositis with or without MSA - Minimal disability defined as at least 10% loss on manual muscle testing (MMT) and abnormal scores on two other Core Set Measures (CSMs) of the international Myositis Assessment and Clinical Studies (IMACS) group. - Newly diagnosed (aim 1+2), established diagnosis (aim 3). - Without immunosuppressive medication (exceptions are allowed; duration of treatment and dosage in case of pre-treatment in combination with the medication-free time interval is at the discretion of treating physician). - Signed informed consent.
Exclusion criteria
Exclusion criteria: - Administration of IVIg in the 12 months before screening. - Conditions that are likely to interfere with o Compliance (legal incompetent and/or incapacitated patients are excluded) o Evaluation of efficacy (e.g., due to severe pre-existing disability because of any other disease than myositis or due to language barrier)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Changes in contractile function (specific force) between 1st and 2nd biopsy after 10 to 15 weeks of treatment with standard of care immunosuppressive medication. | — |
Secondary
| Measure | Time frame |
|---|---|
| Imaging of the muscles: MRI: quantitative assessment of edema, fat infilatration and contractile cross-sectional area, muscle fiber integrity and muscle fiber membrane stability. Ultrasound: qualitative and quantitative analysis; including muscle fiber elasticity and muscle fiber direction. Muscle biopsy: Changes in histological markers between the first and second biopsy. - Complement activation in muscle tissue. - the degree of inflammatory infiltrates. In a few IMNM patients, we will also perform RNA sequencing on immune cells. - the presence of regeneration, degeneration and necrosis. Clinical: Change of muscle strength over time - assessment according to Kendall and isometric knee extension assessment. Clinical improvement and response to treatment by using the Total Improvement Score. Mean daily prednisone dosage | — |
Countries
Netherlands
Outcome results
None listed