Rescue combination treatment of anti-MDA5-associated ARDS with daratumumab

Anti- Melanoma Differentiation-Associated Gene 5 Antibody Positive Dermatomyositis: Recent Progress in Pathophysiology and Treatment

PURPOSE OF REVIEW

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is a rare systemic autoimmune disease characterized by a clinically amyopathic presentation and a high-risk association with rapidly progressive interstitial lung disease. Although frequently fatal, the underlying mechanisms remain incompletely understood. This review provides a comprehensive summary of recent advances in research on MDA5-DM, aiming to deepen our understanding of its pathogenic mechanisms and to accelerate future basic research that will contribute to the development of novel therapeutic strategies.

RECENT FINDINGS

Recent advancements have shed light on various aspects of this disease, including genetic and environmental factors contributing to disease susceptibility and the immunopathological processes and cytokine networks. Furthermore, significant progress has been made in understanding the pathogenicity, epitope recognition, and production mechanisms of anti-MDA5 antibodies, which have long been subjects of debate. On the therapeutic front, in addition to the conventional triple-combination regimen, emerging efficacy of JAK inhibitors and rituximab has been recognized. The development of biologics targeting lymphocytes offers additional hope for advancing therapeutic options. Advancing our understanding of the latest pathophysiological mechanisms of MDA5-DM is expected to pave the way for the development of safer and more effective therapeutic strategies.

Targeting B Cells for the Treatment of Idiopathic Inflammatory Myopathy

Idiopathic inflammatory myopathy (IIM) is a group of heterogeneous diseases that can affect multiple systems. Currently, it is classified into different subtypes based on myositis-specific antibodies and muscle tissue pathology. These subtypes vary in treatment response and clinical prognosis, with poor treatment outcomes observed in cases of rapidly progressive interstitial lung disease and severe muscle involvement. Despite conventional treatments, there remains a high rate of mortality and disability. The production of B cells and autoantibodies plays a crucial role in the pathogenesis of IIM. Targeting B cells has emerged as an effective therapeutic strategy for IIM. This review aims to summarize the current state of B cell-targeted therapies for IIM, providing clinicians with potential treatment options.

Emerging mechanisms and therapeutics in inflammatory muscle diseases

Idiopathic inflammatory myopathies (IIMs), or myositis, are rare diseases marked by immune-driven muscle damage and complications like skin lesions and interstitial lung disease (ILD). Despite advances, challenges in diagnosis and treatment persist, particularly in inclusion body myositis (IBM), where no effective therapy exists. Recent breakthroughs, including transcriptomics and insights into antibody-mediated immunity and interferon (IFN) signaling, have clarified IIM pathophysiology and spurred the development of new therapies, such as chimeric antigen receptor (CAR) T cells and Janus kinase (JAK) inhibitors. We explore the latest findings on the mechanisms underlying adult-onset IIMs, emphasizing IBM pathobiology and its unique immune and degenerative pathways, such as a selective type 2 myofiber damage and severe cell stress. Finally, we highlight the recent advances in transcriptomics, single-cell analysis, and machine learning in transforming IIM research by improving diagnostic accuracy, uncovering therapeutic targets, and supporting the development of personalized treatment strategies.

Dysregulated CD38 expression on T cells was associated with rapidly progressive interstitial lung disease in anti-melanoma differentiation-associated gene 5 positive dermatomyositis

Background

Anti-melanoma differentiation-associated gene 5 positive dermatomyositis (MDA5+ DM) is a life-threatening disease due to rapidly progressive interstitial lung disease (RP-ILD). We aimed to investigate the expression profile of T cell subsets in MDA5+ DM patients, seeking for possible disease-causing T cell subsets and potential biomarkers to distinguish ILD, especially RP-ILD patients.

Methods

Peripheral blood T cell subpopulations were immunophenotyped in 24 MDA5+ DM patients and 21 healthy controls (HCs) by flow cytometry. The proportion of T cell subsets and clinical characteristics were analyzed. The quantitative determination of cytokines in the plasma was measured by using a microsphere-based immunofluorescence assaying kit.

Results

The proportion of naïve and CD38+ T cells were much higher, whereas the proportion of central memory T cells were lower in MDA5+ DM patients than in HCs. Notably, the proportion of CD38+CD4+ T cells and CD38+CD8+ T cells on T cells in in RP-ILD group were significantly elevated compared to C-ILD, non-ILD group and HCs. Moreover, serum IFN-α levels were significantly increased in MDA5+ DM patients with RP-ILD. Further, the frequencies of CD38+CD4+ T cells and CD38+CD8+ T cells were positively correlated with IFN-α levels. Finally, ROC analysis indicated that CD38+CD4+ T cells and CD38+CD8+ T cells could be potential biomarkers for predicting ILD/RP-ILD in MDA5+ DM patients.

Conclusion

Dysregulated CD38 expression on T cell subsets was associated with lung involvement, especially RP-ILD in MDA5+ DM patients. CD38+ T cell subsets could be used as potential biomarkers for predicting ILD/RP-ILD in MDA5+ DM patients.

Antimelanoma differentiation antigen 5-positive dermatomyositis: an update

PURPOSE OF REVIEW

Antimelanoma differentiation antigen 5-dermatomyositis (MDA5-DM) is a complex and serious systemic autoimmune disease that primarily affects the skin and lungs. In this review, we aimed to provide new insights into the clinical features, pathogenesis, and practical management approach for this disease.

RECENT FINDINGS

Although lung lesions are prominent in most patients with MDA5-DM, they are now recognized as heterogeneous diseases. Peripheral blood lymphocyte count can serve as a simple and reliable laboratory parameter for categorizing MDA5-DM into three subgroups: mild, medium, and severe. Recent studies have implicated viral infection, genetic factors, autoimmunity against MDA5, multiple immune cells, and interferons as significant contributors to MDA5-DM pathogenesis. In addition to traditional treatments with glucocorticoids and immunosuppressants, many new approaches, including new biologics and targeted agents, have been explored. Additionally, infection is a common complication of MDA5-DM, and prophylaxis or treatment of the infection is as important as treating the primary disease.

SUMMARY

Knowledge of clinical characteristics and pathogenesis of MDA5-DM has grown in recent years. Although many new therapeutic approaches have been explored, further studies are required to confirm their efficacy.

Daratumumab for autoimmune diseases: a systematic review

OBJECTIVE

Refractory autoimmune diseases remain a significant challenge in clinical practice and new therapeutic options are needed. This systematic review evaluates the existing reported data on the CD38-targeting antibody daratumumab as a new therapeutic approach in autoantibody-mediated autoimmune diseases.

METHODS

A protocolised systematic literature review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. Two databases (Medline and Embase) were searched for suitable studies. Usage of daratumumab in non-oncological or non-transplantation associated diseases with autoimmune pathophysiology was analysed including patient characteristics, therapeutic regimen, adverse events and patient outcome.

RESULTS

38 publications reporting the clinical course of 83 patients met the inclusion criteria. Daratumumab usage was reported in therapy-refractory cases (median of 5 different previous therapies) in 24 different autoimmune diseases. The median number of applications of daratumumab was 4, mainly via intravenous applications (87%). Concomitant treatment included glucocorticoids in 64% of patients, intravenous immunoglobulins (33%) and rituximab (17%). Remission or improvement of disease was reported in 81% of patients. Autoantibody depletion or reduction was stated in 52% of patients. Death occurred in three patients (3%). Adverse events were reported in 45% of patients including application-associated reaction (20%), infection (19%) and hypogammaglobulinaemia (33%).

CONCLUSION

Targeting CD38 via daratumumab is a new promising therapeutic option in therapy refractory autoimmune diseases. Efficacy as well as optimal therapeutic regimen and management or prevention of adverse events require further investigation. Therefore, systematic clinical trials of this therapeutic approach are needed.

IFN-γ: An overlooked cytokine in dermatomyositis with anti-MDA5 antibodies

Dermatomyositis with anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 DM) is a rare autoimmune disease, often complicated by life-threatening, rapidly progressive interstitial lung disease. Additional manifestations of the disease include skin lesions, vascular abnormalities, joints and muscles pain. Despite its clinical significance, the pathogenesis of anti-MDA5 DM remains largely unknown. Currently, the disease is perceived as driven by type I interferon (IFN) whose expression is increased in most of the patients. Importantly, the regulation of IFN-γ is also altered in anti-MDA5 DM as evidenced by the presence of IFN-γ positive histiocytes in the lungs of patients, and the identification of autoantibodies that directly stimulate the production of IFN-γ by mononuclear cells. This review critically examines the pathogenesis of the disease, shedding light on recent findings that emphasize a potential role of IFN-γ. A novel conceptual framework is proposed, which integrates the molecular mechanisms altering IFN-γ regulation in anti-MDA5 DM with the known functional effects of IFN-γ on key tissues affected during the disease, such as the lungs, skin, and vessels. Understanding the precise role and relevance of IFN-γ in the pathogenesis of the disease will not only enhance the selection of available therapies for anti-MDA5 DM patients but also pave the way for the development of new therapeutic approaches targeting the altered molecular pathways.