Intravenous Immunoglobulins in Idiopathic Inflammatory Myopathies: Where Are We?

Idiopathic inflammatory myopathies (IIM) are a group of heterogeneous autoimmune diseases characterized by muscular but also extra-muscular systemic manifestations. IIM may induce severe muscle impairment and be associated with life-threatening complications. Current therapeutic approach includes the combination of corticosteroids (CS) with immunosuppressants (IS). IIM often require prolonged treatment duration, and it is not uncommon that patients present refractory and/or relapsing disease course. CS and IS therapy exposes patients to significant adverse events. Intravenous immunoglobulins (IVIG) have demonstrated their efficacy in many autoimmune diseases and have a better safety profile. This article reviews current evidence on the use of IVIG in IIM and provides guidance for their use in clinical practice.

IVIG have been used worldwide for many years to treat autoimmune diseases. Historically, IVIG have been studied in IIM patients that were categorized in polymyositis and dermatomyositis (DM). Recent studies demonstrated the efficacy of IVIG in DM, and recent classification criteria reconsider the entity of polymyositis.

IVIG are at least partially effective in all IIM subgroups, except IBM. In addition to DM, growing set of data suggests IVIG efficacy in Immune-mediated necrotizing myopathies, but controlled studies are still needed. Improvement in our understanding of pathophysiology in each IIM subgroup should allow performing specific clinical trials.