Subcutaneous immunoglobulin for patients with idiopathic inflammatory myopathies: a real-world single centre experience

Zechen Ma; Dylan Johnson; Robert Gniadecki; Bruce Ritchie; Stephanie Keeling; Jan Willem Cohen Tervaert; Mohammed Osman

doi:10.1093/rheumatology/kead521

Subcutaneous immunoglobulin for patients with idiopathic inflammatory myopathies: a real-world single centre experience

Rheumatology (Oxford). 2023 Oct 5:kead521. doi: 10.1093/rheumatology/kead521. Online ahead of print.

Authors

Zechen Ma¹, Dylan Johnson¹, Robert Gniadecki², Bruce Ritchie³, Stephanie Keeling¹, Jan Willem Cohen Tervaert¹, Mohammed Osman¹

Affiliations

¹ Divsion of Rheumatology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
² Division of Dermatology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
³ Division of Hematology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.

PMID: 37796840
DOI: 10.1093/rheumatology/kead521

Abstract

Objectives: Idiopathic inflammatory myopathies (IIMs) are heterogeneous diseases characterized by skeletal muscle inflammation associated with cutaneous, pulmonary, and/or other visceral organ involvement. Intravenous immunoglobulin (IVIG) has been recommended as an adjunct therapy for IIM patients refractory to conventional therapy. However, IVIG has high resource needs and increased risk of adverse reactions. Subcutaneous immunoglobulin (SCIG) therapy has been used as an alternative to IVIG in primary immunodeficiencies and neuroinflammatory disorders. We assessed the satisfaction, patient preference and effectiveness in IIM patients transitioned from IVIG to SCIG.

Methods: We retrospectively reviewed consecutive 20 patients with IIM who were transitioned from IVIG to SCIG therapy for >12 months. Patient preference between IVIG vs SCIG was surveyed using a questionnaire previously used in studies with neuroinflammatory conditions. In addition, disease flares, changes in immunosuppression, cumulative prednisone doses and global disease activity were evaluated using the Myositis Intention to Treat Index (MITAX) 12-months prior to- and post-SCIG initiation.

Results: Most patients (78.9%) preferred SCIG over IVIG and preferred home-based therapies to hospital-based therapies. There was no significant difference in global disease activity (MITAX 3.31 vs 3.02) nor in cumulative steroid doses 12-months prior to- or post-SCIG initiation. Three patients experienced disease flares, 5 escalated in immunosuppression, while 4 patients deescalated in immunosuppressive medications.

Conclusions: SCIG is preferred by most patients over IVIG without a substantial increased disease activity or need for additional corticosteroids. Future cost effectiveness studies may provide an additional rationale for utilizing SCIG over IVIG for maintenance therapy for IIM.

Keywords: idiopathic inflammatory myositis; immunomodulation; patient satisfaction; subcutaneous immunoglobulin.