Malignancy and myositis, from molecular mimicry to tumor infiltrating lymphocytes

Investigating the disparities among drug categories in drug-induced dermatomyositis: A systematic review

Drug-induced dermatomyositis (DIDM) is a rare and underestimated variant of dermatomyositis (DM) characterized by muscle damage and skin rash and related to certain drug exposure. The spectrum of drugs causing DIDM has evolved over time, originally implicating hydroxyurea, penicillamine, and statins as causative agents. Tumor necrosis factor α inhibitors and immune checkpoint inhibitors have also been associated with such conditions. To bridge the gap between current literature and clinical practice, and therefore guide clinicians, we conducted a comprehensive review of English literature from Pubmed, EMBASE, and MEDLINE. Our analysis included demographic data, clinical features, laboratory findings, therapeutic outcomes, and extant research pertaining to the probable pathogenesis of DIDM induced by various drugs. Furthermore, we categorized the drugs involved in DIDM cases into biologics and traditional agents for subsequent statistical analysis. Over time, there has been a gradual accumulation of reported DIDM cases. A total of 69 published DIDM cases were documented in our study, among which 33 should be attributed to biologics and the remaining 36 to traditional drugs. Interestingly, 41 of all DIDM cases had a previous history of malignancies. Additionally, DIDM cases exhibited similar cutaneous and muscular manifestations to classic DM, with the exception of cases induced by hydroxyurea, which did not entail muscle damage. Positive antinuclear antibodies and anti-TIF1-γ autoantibodies have been predominantly observed in biologics-induced cases, while positive anti-TIF1-γ antibodies were merely reported in the cases that were primarily diagnosed with malignant diseases and exposed to ICIs afterwards. Anti-TIF1-γ antibodies may potentially serve as a red flag in the identification of co-existing malignant diseases in DM patients. We also provided a comprehensive summary and exploration of potential mechanisms lying behind drug-induced dermatomyositis. In conclusion, our review consolidates the current literature on DIDM, highlighting the evolving spectrum of medications and elucidating the differences in clinical manifestations, laboratory findings, and underlying mechanisms.

Genetic Influences in Cancer-Associated Myositis

Idiopathic inflammatory myopathies (IIMs) comprise a heterogeneous group of rare immune-mediated disorders that primarily affect muscles but also lead to dysfunction in other organs. Five different clinical subphenotypes of IIM have been distinguished: dermatomyositis, polymyositis, inclusion body myositis, antisynthetase syndrome, and immune-mediated necrotizing myopathy. Excess mortality and morbidity associated with IIM are largely attributed to comorbidities, particularly cancer. The risk of malignancy is not equally distributed among IIM groups and is particularly high among patients with dermatomyositis. The cancer risk peaks around 3 years on either side of the IIM diagnosis and remains elevated even 10 years after the onset of the disease. Lung, colorectal, and ovarian neoplasms typically arise before the onset of IIM, whereas melanoma, cervical, oropharyngeal, and nonmelanoma skin cancers usually develop after IIM diagnosis. Given the close temporal proximity between IIM diagnosis and the emergence of malignancy, it has been proposed that IIM could be a consequence rather than a cause of cancer, a process known as a paramalignant phenomenon. Thus, a separate group of IIMs related to paramalignant phenomenon has been distinguished, known as cancer-associated myositis (CAM). Although the relationship between IIM and cancer is widely recognized, the pathophysiology of CAM remains elusive. Given that genetic factors play a role in the development of IIM, dissection of the molecular mechanisms shared between IIM and cancer presents an opportunity to examine the role of autoimmunity in cancer development and progression. In this review, the evidence supporting the contribution of genetics to CAM will be discussed.

Autoantibodies: Pathogenic or epiphenomenon

Idiopathic inflammatory myopathies (IIM) are heterogeneous autoimmune diseases. There are distinct subgroups, including antisynthetase syndrome, dermatomyositis, polymyositis, immune-mediated necrotizing myopathy, and sporadic inclusion body myositis. In patients with IIM, autoantibodies are present in up to 80% of the patients. These autoantibodies are often characterized as myositis-specific autoantibodies (MSA) or myositis-associated autoantibodies (MAA). The recognition of the importance of autoantibodies, especially MSA, is increasing in recent years. In this chapter, we provide an overview of the MSAs, including some new autoantibodies of interest as they target mainly muscle-specific autoantigen, in clinical classification, the measurement of the disease activity, and a possible role in the pathogenesis in the patients with IIM.

Inclusion Body Myositis and Neoplasia: A Narrative Review

Inclusion body myositis (IBM) is an acquired, late-onset inflammatory myopathy, with both inflammatory and degenerative pathogenesis. Although idiopathic inflammatory myopathies may be associated with malignancies, IBM is generally not considered paraneoplastic. Many studies of malignancy in inflammatory myopathies did not include IBM patients. Indeed, IBM is often diagnosed only after around 5 years from onset, while paraneoplastic myositis is generally defined as the co-occurrence of malignancy and myopathy within 1 to 3 years of each other. Nevertheless, a significant association with large granular lymphocyte leukemia has been recently described in IBM, and there are reports of cancer-associated IBM. We review the pathogenic mechanisms supposed to be involved in IBM and outline the common mechanisms in IBM and malignancy, as well as the therapeutic perspectives. The terminally differentiated, CD8+ highly cytotoxic T cells expressing NK features are central in the pathogenesis of IBM and, paradoxically, play a role in some cancers as well. Interferon gamma plays a central role, mostly during the early stages of the disease. The secondary mitochondrial dysfunction, the autophagy and cell cycle dysregulation, and the crosstalk between metabolic and mitogenic pathways could be shared by IBM and cancer. There are intermingled subcellular mechanisms in IBM and neoplasia, and probably their co-existence is underestimated. The link between IBM and cancers deserves further interest, in order to search for efficient therapies in IBM and to improve muscle function, life quality, and survival in both diseases.

Pathophysiological Mechanisms and Treatment of Dermatomyositis and Immune Mediated Necrotizing Myopathies: A Focused Review

Idiopathic inflammatory myopathies (IIM), collectively known as myositis, are a composite group of rare autoimmune diseases affecting mostly skeletal muscle, although other organs or tissues may also be involved. The main clinical feature of myositis is subacute, progressive, symmetrical muscle weakness in the proximal arms and legs, whereas subtypes of myositis may also present with extramuscular features, such as skin involvement, arthritis or interstitial lung disease (ILD). Established subgroups of IIM include dermatomyositis (DM), immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), overlap myositis (OM) and inclusion body myositis (IBM). Although these subgroups have overlapping clinical features, the widespread variation in the clinical manifestations of IIM suggests different pathophysiological mechanisms. Various components of the immune system are known to be important immunopathogenic pathways in IIM, although the exact pathophysiological mechanisms causing the muscle damage remain unknown. Current treatment, which consists of glucocorticoids and other immunosuppressive or immunomodulating agents, often fails to achieve a sustained beneficial response and is associated with various adverse effects. New therapeutic targets have been identified that may improve outcomes in patients with IIM. A better understanding of the overlapping and diverging pathophysiological mechanisms of the major subgroups of myositis is needed to optimize treatment. The aim of this review is to report on recent advancements regarding DM and IMNM.

Update on Malignancy in Myositis—Well-Established Association with Unmet Needs

Idiopathic inflammatory myopathies are a group of rare connective tissue diseases with a well-documented association with malignancy. The mechanisms underlying the increased risk of neoplasms in the course of myositis are not fully understood. The Pubmed database has been thoroughly screened for articles concerning cancer-associated myositis (CAM). The article summarizes the current state of knowledge on the epidemiology and pathogenesis of CAM. Furthermore, it analyses potential risk and protective factors for developing CAM, with particular emphasis on the association with distinct serological profiles. The review summarizes recommendations proposed so far for the management of CAM and presents a novel scheme for cancer screening proposed by the authors. Moreover, promising areas requiring further research were indicated.

Inflammatory myopathies in childhood

Myositis in childhood can occur under different conditions and with various aetiologies, juvenile dermatomyositis (jDM) being by far the most frequent entity. The exact diagnostic workup and precise assessment of muscular as well as extramuscular involvement of organs in these systemic autoimmune diseases are relevant for specific and adjunct treatment of complications. Many new insights have become available with respect to the pathophysiological concepts as well as modern diagnostic measures and therapeutic approaches. Autoantibody detection in the serum of children with myositis is one of the major novelties that has become widely used and that is indeed helpful for diagnostic and prognostic measures. The pathophysiological relevance of type I interferons in jDM has been studied intensively in the past years. jDM is now seen as an acquired interferonopathy and first therapeutic consequences have been drawn from this pathogenic finding with the use of Janus-kinase inhibitors for severe and not otherwise treatable children.

Identification of distinct cytokine/chemokine profiles in dermatomyositis with anti-transcriptional intermediary factor 1-γ antibody

OBJECTIVES

Dermatomyositis (DM) and clinically amyopathic dermatomyositis (CADM) patients with positive expression of anti-transcription intermediary factor 1-γ (anti-TIF1-γ) antibody (Ab) are characterized by distinct clinicopathological features. We aimed to determine the role of cytokine/chemokine profiles in the classification of anti-TIF1-γ positive DM/CADM patients.

METHODS

Serum levels of 24 cytokines/chemokines were measured in 27 anti-TIF1-γ positive DM/CADM patients by a Luminex 200 system. Principal components analysis (PCA) and unsupervised hierarchical clustering were used to reduce variables and establish patient subgroups. Spearman's correlation coefficient was calculated between cytokine/chemokine levels and disease activity markers.

RESULTS

Among anti-TIF1-γ positive DM/CADM patients, two distinct patient clusters were identified. The diagnosis of CADM was more common in Cluster 1 than in Cluster 2 (58.3% vs 6.7%, p = 0.008). Skin disease activity was higher in Cluster 2 than in Cluster 1 as measured by CDASI-A (38.6 ± 10.4 vs 25.3 ± 10.0, p = 0.003). Patients within Cluster 2 exhibited significant muscle weakness (MRC ≤ 3, 33.3% vs 0.0%, p = 0.047), higher levels of anti-TIF1-γ Ab (92.4 ± 20.6 vs 66.9 ± 13.9, p = 0.001), and an increased malignancy rate (73.3% vs 25.0%, p = 0.021). Cluster 2 exhibited higher serum levels of CXCL10 (564.2 ± 258.8 vs 122.0 ± 97.8, p < 0.001), CCL2 (1136.6 ± 545.4 vs 441.6 ± 163.3, p < 0.001), Galectin-9 (38879.6 ± 20009.3 vs 12612.4 ± 6640.0, p < 0.001), IL-18 (436.1 ± 188.9 vs 243.0 ± 114.5, p = 0.003), TNF-α (9.3 ± 3.8 vs 5.6 ± 2.4, p = 0.007), and TNFRI (1385.1 ± 338.2 vs 2605.6 ± 928.5, p < 0.001) than Cluster 1.

CONCLUSION

In anti-TIF1-γ positive DM/CADM, we identified a "skin-predominant" cluster and a "hyperinflammation" cluster based on the cytokine/chemokine profiles. Cytokine/chemokine profiles in anti-TIF1-γ positive DM/CADM can identify discrete clusters of patients with different disease patterns, organ involvements, and clinical outcomes.

Reappraisal of the incidence, various types and risk factors of malignancies in patients with dermatomyositis and polymyositis in Taiwan

Our study aimed to investigate the incidence, risk factors and time to occurrence of malignancy in patients with dermatomyositis (DM) and polymyositis (PM). The electronic medical records of 1100 patients with DM and 1164 patients with PM were studied between January 2001 and May 2019. Malignancies after myositis were diagnosed in 61 (5.55%) patients with DM and 38 (3.26%) patients with PM. The cumulative incidence of malignancies in patients with DM were significantly higher than patients with PM (hazard ratio = 1.78, log-rank p = 0.004). Patients with DM had a greater risk of developing malignancy than those with PM at 40–59 years old (p = 0.01). Most malignancies occurred within 1 year after the initial diagnosis of DM (n = 35; 57.38%). Nasopharyngeal cancer (NPC) was the most common type of malignancy in patients with DM (22.95%), followed by lung, and breast cancers. In patients with PM, colorectal, lung and hepatic malignancies were the top three types of malignancy. The risk factors for malignancy included old age (≥ 45 years old) and low serum levels of creatine phosphokinase (CPK) for patients with DM and male sex and low serum levels of CPK for patients with PM. Low serum levels of CPK in patients with myositis with malignancy represented a low degree of muscle destruction/inflammation, which might be attributed to activation of the PD-L1 pathway by tumor cells, thus inducing T-cell dysfunction mediating immune responses in myofibers. A treatment and follow-up algorithm should explore the occurrence of malignancy in different tissues and organs and suggested annual follow-ups for at least 5.5 years to cover the 80% cumulative incidence of malignancy in patients with DM and PM.

The Paired Siglecs in Brain Tumours Therapy: The Immunomodulatory Effect of Dexamethasone and Temozolomide in Human Glioma In Vitro Model

The paired sialic acid-binding immunoglobulin like lectins (Siglecs) are characterized by similar cellular distribution and ligand recognition but opposing signalling functions attributed to different intracellular sequences. Since sialic acid—Siglec axis are known to control immune homeostasis, the imbalance between activatory and inhibitory mechanisms of glycan-dependent immune control is considered to promote pathology. The role of sialylation in cancer is described, however, its importance in immune regulation in gliomas is not fully understood. The experimental and clinical observation suggest that dexamethasone (Dex) and temozolomide (TMZ), used in the glioma management, alter the immunity within the tumour microenvironment. Using glioma-microglia/monocytes transwell co-cultures, we investigated modulatory action of Dex/TMZ on paired Siglecs. Based on real-time PCR and flow cytometry, we found changes in SIGLEC genes and their products. These effects were accompanied by altered cytokine profile and immune cells phenotype switching measured by arginases expression. Additionally, the exposure to Dex or TMZ increased the binding of inhibitory Siglec-5 and Siglec-11 fusion proteins to glioma cells. Our study suggests that the therapy-induced modulation of the interplay between sialoglycans and paired Siglecs, dependently on patient’s phenotype, is of particular signification in the immune surveillance in the glioma management and may be useful in glioma patient’s therapy plan verification.