Successful Rescue Therapy With Daratumumab in Rapidly Progressive Interstitial Lung Disease Caused by MDA5-Positive Dermatomyositis

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.

Disease-associated immune cell endotypes in anti-MDA5-positive dermatomyositis using unbiased hierarchical clustering

Objective

Clinical and prognostic features of Anti-MDA5-Positive Dermatomyositis (MDA5+ DM) are diverse. This study aimed to examine the peripheral immune cell profiles of patients with MDA5+ DM, identify disease endotypes related to the heterogeneous manifestations and prognosis, and guide individualized therapy regimen.

Methods

This inpatient cohort included 123 patients with MDA5+ DM. Unsupervised hierarchical clustering analysis was used to derive disease endotypes from the circulating immune cell profiles on admission. Clinical symptoms, laboratory test results, inpatient treatments, and disease outcomes were then analyzed among the identified endotypes.

Results

Three disease endotypes in MDA5+ DM were identified from peripheral immune cell profiles. Endotype1 had the highest percentages of CD4+ T cells and monocytes, and the lowest percentage of neutrophils; Endotype2 had the highest percentage of B cells; Endotype3 had the highest percentage of CD8+ T cells and NK cells. Clinical and prognostic heterogeneity of the endotypes were revealed. Endotype1 had the lowest 3-month mortality with the high incidence of periungual capillary changes. Endotype2 and Endotype3 had higher prevalence of rapidly progressive interstitial lung disease (RPILD) and mortality at 3 months than Endotype1. Meanwhile, Endotype3 had higher pneumocystis jiroveci and CMV viremia cases with significantly elevated of activated CD8+ T cells and multiple cytokines than Endotype1.

Conclusion

Clustering analysis of peripheral immune cell profiles identified three different endotypes in MDA5+ dermatomyositis. Endotpye2 and 3 showed higher RPILD, 3-month mortality, pneumocystis jiroveci and CMV viremia.

Dermatomyositis: Practical Guidance and Unmet Needs

Dermatomyositis is a heterogeneous idiopathic inflammatory myopathy associated with various cutaneous manifestations and variable presence of myositis, interstitial lung disease, and other visceral organ involvement. An accurate diagnosis of dermatomyositis requires correlating clinical examination findings with serological and histological findings. Familiarity with pathognomonic and common cutaneous manifestations of dermatomyositis, which are highlighted here, can be especially helpful in making an accurate diagnosis. Additionally, evaluating patients for presence of myositis-specific autoantibodies can further support or refute a dermatomyositis diagnosis. When present, myositis-specific autoantibodies can also help guide workups for various dermatomyositis-associated manifestations, as each is associated with relatively distinct clinical characteristics. Evaluating patients for various systemic manifestations often relies on expert opinion recommendations; however, societal guideline statements concerning the evaluation of some manifestations have recently been described. Although malignancy-associated dermatomyositis is a well-accepted subtype, there is limited evidence to support extensive malignancy screening has a favorable benefit-risk ratio in most dermatomyositis patients. However, recent research has uncovered novel associations between dermatomyositis and malignancy, suggesting the possibility of identifying high-risk subsets of dermatomyositis patients in whom malignancy screening may have a high value. Treatment for dermatomyositis has remained largely unchanged over the past several decades. Although many dermatomyositis patients can be effectively treated with current options, either as monotherapy or with combination regimens, there is a need for more targeted and effective DM therapies, in general, and for MDA5(+) dermatomyositis-associated rapidly progressive interstitial lung disease. Fortunately, significant current and emerging research activities evaluating various novel medications for dermatomyositis provide hope for exciting future advances in patients with this intriguing immune-mediated disease.

Anti-MDA5 antibody-positive dermatomyositis: pathogenesis and clinical progress

Anti-melanoma differentiation-associated protein 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is a subtype of dermatomyositis. Although the aetiology and pathology remain unclear, increasing evidence suggests that viral infection is a potential trigger of MDA5-DM. Multiple factors, including T cells, B cells, neutrophils and macrophages, are implicated in the pathophysiology of MDA5-DM. Distinctive skin rashes, rapidly progressive interstitial lung disease, peripheral lymphopenia and elevated serum ferritin levels are the most prominent clinical and laboratory features of MDA5-DM. Concomitant infection is a common complication of MDA5-DM. The proper evaluation of patients with MDA5-DM requires knowledge of the disease heterogeneity and clinical course variability. Several biomarkers, including serum levels of anti-MDA5 antibodies and biomarkers related to macrophage activation, have been identified as useful tools for monitoring disease activity and prognosis. MDA5-DM shows a poor response to conventional glucocorticoid and immunosuppressant therapy and has a poor overall prognosis. Therefore, there is an urgent need to explore the key pathogenic mechanisms of MDA5-DM and develop novel therapeutic options for patients. This Review discusses recent clinical progress and pathogenic findings of MDA5-DM.

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.