From the Research
Introduction to Myositis Treatment
Myositis, a group of inflammatory muscle diseases, requires a comprehensive treatment approach. The primary goal of treatment is to reduce inflammation, improve muscle strength, and prevent long-term damage.
First-Line Treatment
The standard initial treatment for myositis is high-dosed glucocorticoids, such as prednisone 1. However, this treatment may result in relatively slow improvement of muscle strength.
Alternative and Adjunctive Therapies
Intravenous Immunoglobulin (IVIg)
IVIg has shown promise as an add-on therapy to standard glucocorticoid treatment, particularly in patients with refractory myositis or those who are treatment-naive 1, 2. The dosing of IVIg is typically 2 g/kg body weight, administered monthly 3.
Immunomodulatory Therapies
Immunosuppressants, such as azathioprine, mycophenolate, methotrexate, or cyclosporine, may be used as steroid-sparing agents or in patients who are insufficiently responsive to corticosteroids 2.
Biologic Agents
Rituximab and tacrolimus may offer additional benefit in patients with myositis, although their use is not yet widely established 2.
Special Considerations
Myositis-Associated Interstitial Lung Disease (ILD)
Patients with myositis-ILD require a multidisciplinary approach to management, involving both rheumatology and pulmonary specialists 4.
Secondary Causes of Myositis
Infections, drugs, rheumatologic diseases, and malignancies can cause myositis, and identifying these underlying causes is crucial for effective treatment 5.
Treatment Caveats
- The treatment approach may vary depending on the specific type of myositis, such as polymyositis, dermatomyositis, or inclusion body myositis.
- Patients with sporadic inclusion body myositis (s-IBM) may have a limited response to treatment, and high-dose IVIg may be mildly effective in preventing disease progression or inducing mild improvement 3.
- Long-term studies are needed to evaluate the benefit of IVIg therapy in s-IBM.
Conclusion
The treatment of myositis requires a comprehensive and individualized approach, taking into account the specific type of myositis, underlying causes, and disease severity. A combination of glucocorticoids, IVIg, and immunomodulatory therapies may be necessary to achieve optimal outcomes.