Intravenous immunoglobulin therapy for severe idiopathic inflammatory myopathies (excluding inclusion body myositis)

Aggarwal, 2022Anh-Tu Hoa, 2017Ashton, 2021Pipitone, 2020Schmidt, 2018

Note: Refer patients with severe idiopathic inflammatory myopathy urgently to a specialist centre.

People with severe dermatomyositis or necrotising autoimmune myopathy (NAM) may have severe proximal weakness, dysphagia and risk of aspiration. Refer patients with severe disease urgently to a specialist centre. For these people, intravenous immunoglobulin (IVIg)1 has been reported to be effectiveAnh-Tu Hoa, 2017Ashton, 2021. Three scenarios in which IVIg should be considered, under the care of a specialist, are:

  • induction therapy—for people with severe disease, especially those with dysphagia and risk of aspiration (whether they are pregnant or not), IVIg is used in combination with pulse intravenous corticosteroids and other csDMARDs (eg azathioprine)
  • maintenance therapy—for a patient with severe disease, where first-line treatments (eg systemic corticosteroids, csDMARDs) have been ineffective, the patient has contraindications to first-line treatment, or the patient is pregnant
  • flare management.

When an idiopathic inflammatory myopathy does not respond to first-line immunomodulatory therapy or is not adequately controlled, review the diagnosis. Exclude other differential diagnoses before changing the treatment (eg switching drugs, combining drugs, adding IVIg or rituximab).

1 Intravenous immunoglobulin is only indicated in people with severe polymyositis, dermatomyositis or necrotising autoimmune myopathy, for treatment of significant muscle weakness or dysphagia unresponsive to corticosteroids or other immunomodulatory drugsIg Governance, 2020.Return