Subsets of Idiopathic Inflammatory Myositis Enriched for Contemporaneous Cancer Relative to the General Population

Review of Pulmonary Manifestations in Antisynthetase Syndrome

Antisynthetase syndrome (ASyS) is now a widely recognized entity within the spectrum of idiopathic inflammatory myopathies. Initially described in patients with a triad of myositis, arthritis, and interstitial lung disease (ILD), its presentation can be diverse. Additional common symptoms experienced by patients with ASyS include Raynaud's phenomenon, mechanic's hand, and fever. Although there is a significant overlap with polymyositis and dermatomyositis, the key distinction lies in the presence of antisynthetase antibodies (ASAs). Up to 10 ASAs have been identified to correlate with a presentation of ASyS, each having manifestations that may slightly differ from others. Despite the proposal of three classification criteria to aid diagnosis, the heterogeneous nature of patient presentations poses challenges. ILD confers a significant burden in patients with ASyS, sometimes manifesting in isolation. Notably, ILD is also often the initial presentation of ASyS, requiring pulmonologists to remain vigilant for an accurate diagnosis. This article will comprehensively review the various aspects of ASyS, including disease presentation, diagnosis, management, and clinical course, with a primary focus on its pulmonary manifestations.

Causality Assessment Between Idiopathic Inflammatory Myopathies and Lung Cancer: A Bidirectional 2-Sample Mendelian Randomization

BACKGROUND

Although observational studies have revealed associations between idiopathic inflammatory myopathies (IIMs) and lung cancer (LC), they have not established a causal relationship between these 2 conditions.

METHODS

We used a 2-sample Mendelian randomization approach to examine the bidirectional causal associations between IIMs and LC, using single-nucleotide polymorphisms selected from high-quality genome-wide association studies in the FinnGen database. Sensitivity analyses were conducted to assess potential heterogeneity and pleiotropy impacts on the Mendelian randomization results.

RESULTS

Our analysis demonstrated a positive causal effect of genetically increased IIM risk on LC (odds ratio, 1.114; 95% confidence interval, 1.057-1.173; p = 5.63 × 10 -5 ), particularly on the lung squamous cell carcinoma subtype (odds ratio, 1.168, 95% confidence interval, 1.049-1.300, p = 0.00451), but not on lung adenocarcinoma or small cell lung cancer. No causal effect of LC on IIMs was identified. Sensitivity analyses indicated that horizontal pleiotropy was unlikely to influence causality, and leave-one-out analysis confirmed that the observed associations were not driven by a single-nucleotide polymorphism.

CONCLUSION

Our findings offer compelling evidence of a positive causal relationship between IIMs and LC, particularly with regard to lung squamous cell carcinoma, in the European population. Conversely, there is no evidence of LC causing IIMs. We recommend that LC diagnosis consider the specific characteristics of IIMs.

Circulating extracellular vesicles and small non-coding RNAs cargo in idiopathic inflammatory myopathies reveal differences across myositis subsets

OBJECTIVE

To investigate the epigenetic footprint of idiopathic inflammatory myopathies (IIM) through characterization of circulating extracellular vesicles (EVs) and the expression of EV-derived small non-coding RNAs (sncRNAs).

METHODS

In this cross-sectional study, EVs were isolated by size-exclusion chromatography from plasma of patients with IIM and age- and sex-matched healthy donors (HD). EV-derived sncRNAs were sequenced and quantified using Next-Generation Sequencing (NGS). Following quality control and normalization, filtered count reads were used for differential microRNA (miRNA) and piwi-interacting RNA (piRNA) expression analyses. Putative gene targets enriched for pathways implicated in IIM were analyzed. Patients' clinical and laboratory characteristics at the time of sampling were recorded.

RESULTS

Forty-seven IIM patients and 45 HD were enrolled. MiR-486-5p (p < 0.01), miR-122-5p, miR-192-5p, and miR-32-5p were significantly upregulated (p < 0.05 for all), while miR-142-3p (p < 0.001), miR-141-3p (p < 0.01), let-7a-5p (p < 0.05) and miR-3613-5p (p < 0.05) downregulated in EVs from IIM patients versus HD. MiR-486-5p was associated with raised muscle enzymes levels. Several target genes of up/downregulated miRNAs in IIM participate in inflammation, necroptosis, interferon and immune signaling. Six piRNAs were significantly dysregulated in IIM EVs versus HD (p < 0.05). Within IIM, miR-335-5p was selectively upregulated and miR-27a-5p downregulated in dermatomyositis (n = 21, p < 0.01). Finally, plasma EV levels were significantly increased in cancer-associated myositis (CAM, n = 12) versus non-CAM IIM (n = 35, p = 0.02) and HD (p < 0.01). EVs cargo in CAM was significantly enriched of let-7f-5p and depleted of miR-143-3p.

CONCLUSION

Through an unbiased screening of EV-derived sncRNAs, we characterize miRNAs and piRNAs in the EVs cargo as potential biomarkers and modifiers of diverse IIM phenotypes.

Immune-Mediated Necrotizing Myopathies: Current Landscape

PURPOSE OF REVIEW

Immune-mediated necrotizing myopathy (IMNM), characterized by acute or subacute onset, severe weakness, and elevated creatine kinase levels, poses diagnostic and therapeutic challenges. This article provides a succinct overview of IMNM, including clinical features, diagnostic strategies, and treatment approaches.

RECENT FINDINGS

Recent insights highlight the different clinical presentations and therapeutic options of IMNM stratified by autoantibody positivity and type. Additionally, recent findings call into question the reported link between statin use and IMNM. This review synthesizes current knowledge on IMNM, emphasizing its distinct clinical features and challenging management. The evolving understanding of IMNM underscores the need for a comprehensive diagnostic approach that utilizes a growing range of modalities. Early and aggressive immunomodulatory therapy remains pivotal. Ongoing research aims to refine diagnostic tools and therapeutic interventions for this challenging muscle disorder, underscoring the importance of advancing our understanding to enhance patient outcomes.

Anti-MDA5 Antibody-Positive Clinically Amyopathic Dermatomyositis Associated With Multiple Heterologous Carcinomas: A Case Report

Dermatomyositis (DM), an autoimmune disorder, is linked to increased malignancy risk. A 53-year-old man with anti-melanoma differentiation-associated gene 5 (MDA5)-positive clinically amyopathic dermatomyositis (CADM) and rapidly progressing interstitial lung disease (RP-ILD) developed heterochronous gastric and colorectal cancers. Early endoscopic screenings led to successful curative resections, preventing recurrence. Despite low cancer incidence assumptions in patients with anti-MDA5-positive RP-ILD, this case advocates for reevaluation and periodic cancer screenings to enhance management, considering the improved survival with intensive therapy. Vigilance for multiple carcinomas at various time points is vital in CADM management.

Disease patterns and specific trajectories of anti-MDA5-related disease: a multicentre retrospective study of 70 adult patients

Introduction

This study aimed to provide an updated analysis of the different prognostic trajectories of patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibodies.

Methods

Among a cohort of 70 patients, baseline characteristics and phenotypes, treatments and outcomes were analyzed. A Cox proportional hazards model was used to identify factors associated with poor outcomes, i.e., death or progressive disease at the last follow-up.

Results

Among the 70 patients, 45 were women, and 54 were Caucasian. A dermatologic involvement was observed in 58 (83%) patients, including 40 with MDA5 vasculopathy-related skin lesions. Muscular involvement was observed in 39 (56%) patients. Interstitial lung disease (ILD) was observed at baseline in 52 (74%) patients, including 23 (44%) who developed rapidly progressive (RP) ILD. Seven (10%) patients showed thromboembolic complications within the first weeks of diagnosis, and eight (11%) other patients developed a malignancy (4 before the diagnosis of anti-MDA5 disease). Poor outcomes were observed in 28 (40%) patients, including 13 (19%) deaths. Among the 23 patients with RP-ILD, 19 (79%) showed poor outcomes, including 12 (63%) who died. In multivariate analyses, RP-ILD (hazard ratio (HR), 95% CI: 8.24 [3.21-22], p<0.0001), the occurrence of thromboembolic events (HR: 5.22 [1.61-14.77], p=0.008) and the presence of any malignancy (HR: 19.73 [6.67-60], p<0.0001) were the three factors independently associated with poor outcomes.

Discussion

This new independent cohort confirms the presence of different clinical phenotypes of anti-MDA5 diseases at baseline and the poor prognosis associated with RP-ILD. Thromboembolic events and malignancies were also identified as prognostic factors.

Paraneoplastic myopathies

This chapter reviews the association between cancer and the idiopathic inflammatory myopathies (IIM), which includes dermatomyositis (DM), antisynthetase syndrome (ASyS), immune-mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM). Accumulating evidence shows that the risk of a coexisting malignancy is high in patients with DM, especially among those with anti-Tif1γ autoantibodies. Patients with IMNM and no defined autoantibodies also have an increased risk of malignancy. Recent evidence demonstrates that many IBM patients have increased numbers of circulating CD57+ CD8+ T cells, consistent with a diagnosis of large granular lymphocytic leukemia. In contrast, IMNM patients with anti-SRP or anti-HMGCR autoantibodies as well as patients with ASyS syndrome do not have a definitively increased risk of cancer. Patients who have a cancer treated with one of the immune checkpoint inhibitors can develop myositis (ICI-myositis), sometimes along with myasthenia gravis and/or myocarditis.

Clinical features of dermatomyositis patients with anti-TIF1 antibodies: A case based comprehensive review

BACKGROUND AND OBJECTIVES

Dermatomyositis is chronic autoimmune disease primarily affecting skin and muscles. Antibodies are key players of pathogenesis and are in strong correlation with distinct clinical phenotypes. We present a case and a comprehensive review of the literature on dermatomyositis patients with Anti TIF1 antibodies.

METHODS

PubMed and Web of Science databases were reviewed. 166 articles were identified; 95 of them were evaluated; 79 of them included to the study. 45 of the included articles were case reports 9 were case series and 25 were research articles. In total 1065 patients were identified but number of patients with available information for different clinical features varied.

RESULTS

69.6% of the patients with Anti TIF1-γ were female. Prevalence of malignancy was 42.6% among patients with Anti TIF1-γ. Muscle weakness (83%), Gottron sign (82.2%), heliotrope rash (73.7%), nailfold capillary changes (67.7%), dysphagia (38.4%), and joint involvement (31.1%) were the most common clinical features seen in patients with Anti TIF1-γ. Interstitial lung disease (ILD) was reported among 8.7% of patients with Anti TIF1-γ. Advanced age, male gender, dysphagia, and V-neck rash were significant risk factors for malignancy, whereas juvenile age, ILD, TIF1-β antibodies and joint involvement were associated with a decreased risk for malignancy. Advanced age, malignancy, dysphagia, and muscle involvement were associated with an increased risk for mortality.

CONCLUSIONS

Patients with advanced age, male gender, dysphagia, and V-neck rash require strict cancer screening. Patients with advanced age, malignancy, dysphagia, and muscle involvement have poor prognosis and should receive aggressive treatment.