Critical review of the role of intravenous immunoglobulins in idiopathic inflammatory myopathies

Abstract

Objective: The aim of this review was to summarize key findings from the literature concerning the therapeutic role of intravenous immunoglobulins (IVIg) in idiopathic inflammatory myopathies (IIM), dissecting the evidence according to disease subtype and treatment indication, and to review the evidence relating to the mechanism of action of IVIg in IIM to ascertain rationale for continued research.

Methods: Medline (Ovid) and Pubmed databases were searched from inception to July 2016 using relevant keywords. Original and review articles were retrieved for full-text review. Bibliographies of selected articles were also hand-searched for additional references. Data were summarized qualitatively and in tabular form.

Results: The efficacy of IVIg in IIM is supported by 3 randomized controlled trials, involving dermatomyositis and polymyositis subjects, in refractory, relapsed, or steroid-dependent disease, as well as part of first-line therapy in elderly dermatomyositis subjects. Other indications for IVIg are supported by uncontrolled evidence only. Limitations of studies include open, uncontrolled or retrospective study designs, small and selected samples, short-term follow-up and ad hoc outcome measures. Despite the limited evidence, there is strong biological plausibility for the role of IVIg in IIM.

Conclusion: Robust, controlled evidence to support the use of IVIg using validated outcome measures is urgently required to guide therapeutic decision-making and maximize outcomes in IIM.

Keywords: Anti-HMGCR antibody-associated necrotizing autoimmune myopathies; Cancer-associated myositis; Connective tissue disease-related myositis; Dermatomyositis; Intravenous immunoglobulin; Polymyositis.