2026-06-17 | Successful corticosteroid-free management of anti-HMG-CoA reductase immune-mediated necrotizing myopathy with subcutaneous immunoglobulins monotherapy: a case report.
Given the high rate of cardiovascular comorbidities in anti-HMG-CoA reductase (HMGCR)-immune-mediated necrotizing myopathy (IMNM), a glucocorticosteroids (GC)-free treatment approach remains an appealing strategy. While intravenous immunoglobulins (IVIg) represents an effective therapy in most subgroups of idiopathic inflammatory myositis (IIM), there remains limited evidence supporting the use subcutaneous immunoglobulins (SCIg), a potentially safer, more convenient and cost-effective alternative. We present a case of a 68-year-old male of European descent with a 2-year history of progressive proximal bilateral lower extremity weakness. He had been treated for his dyslipidemia with atorvastatin for 2 years, then with rosuvastatin for 2 additional years until discontinued a year before our assessment. His other comorbidities included hypertension and diabetes mellitus type II. Physical examination demonstrated proximal weakness of his bilateral hip flexors and deltoids, and no rash. His creatine kinase (CK) was elevated at 1644 IU/L. Electromyography revealed a generalized myopathic disorder with proximal predominance and muscle biopsy of the right quadriceps showed typical findings of an IMNM. Serum HMG-CoA reductase antibody was positive. Due to accumulating evidence supporting the effectiveness of IVIg in anti-HMGCR-IMNM, even without concomitant GC or other immunosuppressive agent, we opted for a GC-free approach through shared-decision making in light of patient's preference regarding potential GC side effects with his comorbidities. As he lived a considerable distance from any center, where IVIg infusions could be offered, and given the patient was unable to drive himself due to his symptoms we opted for SCIg (0.5 g/kg/week). Within 1 month, his CK decreased and weakness resolved. SCIg monotherapy was tapered over 3 years and this patient remains in remission 7 years after SCIg initiation. The patient did not have any adverse effects related to SCIg use. To our knowledge, this is the first case report describing a successful corticosteroid-free management of anti-HMGCR immune-mediated necrotizing myopathy using SCIg as monotherapy. This case highlights the potential for steroids-free induction and maintenance strategies in IMNM. Larger studies are required to confirm the effectiveness and safety of SCIg in IMNM and other subtypes of IIM, and to provide guidelines for dosing recommendations.
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2026-06-04 | Role of myositis autoantibodies in diagnosing interstitial lung disease in patients with idiopathic inflammatory myopathies: a retrospective analysis
Background Idiopathic inflammatory myopathies (IIMs) are frequently complicated by interstitial lung disease (ILD). The independent clinical significance of myositis autoantibody positivity remains incompletely defined.Methods We performed a retrospective cohort study of patients undergoing myositis autoantibody testing at a single tertiary center (1997–2022). Multivariable logistic regression assessed the association between antibody positivity and ILD. Subgroup analyses evaluated clinical phenotypes and radiologic patterns.Results Among 1,034 patients included in the analysis, 359 (34.7%) were positive for at least one myositis autoantibody and 365 (35.5%) had ILD. Antibody-positive patients were younger, more frequently female, and had a higher prevalence of ILD compared to antibody-negative patients (41.2% vs 32.2%, p < 0.01).Myositis antibody positivity was independently associated with ILD (adjusted OR 1.78, 95% CI 1.33–2.37, p < 0.001). Increasing age, higher BMI, former smoking status, and Asian ethnicity were also associated with ILD. Among patients with ILD, antibody-positive individuals had a higher prevalence of systemic autoimmune features, including Raynaud’s phenomenon, arthritis, and mechanic’s hands, as well as higher inflammatory markers and more impaired pulmonary function.Conclusion Myositis autoantibody positivity is independently associated with ILD and identifies a distinct clinical phenotype. These findings should be interpreted in the context of the study’s retrospective, single-center design.
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2026-05-30 | The role of B cells in idiopathic inflammatory myopathies
Idiopathic inflammatory myopathies are a heterogeneous group of autoimmune disorders characterized by skeletal muscle inflammation and systemic immune activation. Although traditionally viewed as T cell-driven diseases, recent evidence suggests that B lymphocytes may also contribute to disease mechanisms through both antibody-dependent and noncanonical pathways. Beyond their role in autoantibody production, B cells might influence immune regulation by modulating cytokine networks, presenting antigens, and interacting with T cells and stromal elements within inflamed tissues. These findings have prompted renewed interest in understanding B cell heterogeneity and its possible impact on the initiation and maintenance of chronic inflammation in idiopathic inflammatory myopathies. However, the exact contribution of these cells to tissue damage and clinical variability remains uncertain. Advances in high-dimensional cytometry, transcriptomics, and tissue profiling are beginning to delineate distinct B cell signatures associated with disease activity, yet the causal links to pathogenesis remain unclear. The observed clinical benefit of B cell-depleting therapies, though variable among patients, reinforces their potential relevance while underscoring the complexity of immune interactions in idiopathic inflammatory myopathies. This review aims to synthesize current knowledge on B cells in idiopathic inflammatory myopathies and to discuss how emerging mechanistic insights could refine our understanding of disease heterogeneity and guide future therapeutic approaches.
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