Defining cancer risk in dermatomyositis. Part II. Assessing diagnostic usefulness of myositis serology

Systemic autoimmune rheumatic diseases as paraneoplastic phenomena: 3 illustrative case reports and narrative review of the literature

OBJECTIVES

Systemic autoimmune rheumatic diseases can occur as paraneoplastic phenomena in the context of underlying malignancies. We present three illustrative clinical cases and a narrative literature review focusing on systemic sclerosis, dermatomyositis and palmar fasciitis and polyarthritis syndrome.

METHODS

Medical data of three patients from the University Hospitals Leuven were retrospectively and anonymously obtained and reviewed. A narrative review was performed, searching the databases of PubMed, Embase and Cochrane Library.

RESULTS

Systemic sclerosis, dermatomyositis and palmar fasciitis and polyarthritis syndrome are systemic autoimmune rheumatic diseases that can present as paraneoplastic phenomena. Systemic autoimmune rheumatic diseases are often associated with the presence of specific autoantibodies, some associated with a high likelihood of underlying malignancy. The presence of anti-ribonucleic acid polymerase III antibodies and anti-transcription intermediary factor 1 gamma antibodies indicates an increased risk of underlying cancer in systemic sclerosis and dermatomyositis, respectively. Individual patient prognosis can be improved through early detection of underlying malignancy, hence the importance of adequate cancer screening.

CONCLUSION

Some systemic autoimmune rheumatic diseases can appear as paraneoplastic phenomena, whereby the presence of specific autoantibodies is known to be related to the likelihood of underlying malignancy. We highlight the importance of clinician's knowledge of these distinct features, as it facilitates early detection and treatment of underlying malignancy, thereby improving individual patient prognosis.

The Role of Myositis-Specific Autoantibodies in the Dermatomyositis Spectrum

Dermatomyositis (DM) is a systemic autoimmune disease that affects skeletal muscles, the skin, and the lungs. It is characterized by autoantibodies, tissue inflammation, parenchymal cell damage, death, and vasculopathy. In terms of epidemiology, DM affects both children and adults. The current pathophysiology of DM is described as an autoimmune attack on the afflicted organs driven by environmental variables such as UV exposure, medications, infections, and lifestyle choices in genetically predisposed people. DM is also a paraneoplastic condition, which means that cancer may arise before, along with, or following the development of the symptoms of DM. Myositis-specific autoantibodies are associated with phenotypical features and are used for sub-classification of dermatomyositis patients. Because the risk of interstitial lung disease (ILD), internal malignancy, destructive disease trajectory, and maybe a response to medication differs by DM myositis-specific antibody (MSA) group, a better knowledge of MSAs and the validation and standardization of tests employed for detection is crucial for improving diagnosis and treatment. The diagnostic sensitivity and specificity of tests for various MSAs are not ideal, just like with any other test. However, more antibody tests are anticipated to make their way into formal schemata for diagnosis and actionable risk assessment in DM due to worldwide standardization and more extensive research. In this review, we outline crucial aspects for interpreting clinical and pathologic relationships with MSA in DM and critical knowledge and practice gaps that will optimize the clinical benefit and utility of MSAs as diagnostic and prognostic markers.

Idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM), also known as myositis, are a heterogeneous group of autoimmune disorders with varying clinical manifestations, treatment responses and prognoses. Muscle weakness is usually the classical clinical manifestation but other organs can be affected, including the skin, joints, lungs, heart and gastrointestinal tract, and they can even result in the predominant manifestations, supporting that these are systemic inflammatory disorders. Different myositis-specific autoantibodies have been identified and, on the basis of clinical, histopathological and serological features, IIMs can be classified into several subgroups — dermatomyositis (including amyopathic dermatomyositis), antisynthetase syndrome, immune-mediated necrotizing myopathy, inclusion body myositis, polymyositis and overlap myositis. The prognoses, treatment responses and organ manifestations vary among these groups, implicating different pathophysiological mechanisms in each subtype. A deeper understanding of the molecular pathways underlying the pathogenesis and identifying the autoantigens of the immune reactions in these subgroups is crucial to improve outcomes. New, more homogeneous subgroups defined by autoantibodies may help define disease mechanisms, and will also be important in future clinical trials to develop targeted therapies and in identifying biomarkers to guide treatment decisions for the individual patient.

Idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM), also known as myositis, are a heterogeneous group of autoimmune disorders with varying clinical manifestations, treatment responses and prognoses. Muscle weakness is usually the classical clinical manifestation but other organs can be affected, including the skin, joints, lungs, heart and gastrointestinal tract, and they can even result in the predominant manifestations, supporting that IIM are systemic inflammatory disorders. Different myositis-specific auto-antibodies have been identified and, on the basis of clinical, histopathological and serological features, IIM can be classified into several subgroups - dermatomyositis (including amyopathic dermatomyositis), antisynthetase syndrome, immune-mediated necrotizing myopathy, inclusion body myositis, polymyositis and overlap myositis. The prognoses, treatment responses and organ manifestations vary among these groups, implicating different pathophysiological mechanisms in each subtype. A deeper understanding of the molecular pathways underlying the pathogenesis and identifying the auto-antigens of the immune reactions in these subgroups is crucial to improving outcomes. New, more homogeneous subgroups defined by auto-antibodies may help define disease mechanisms and will also be important in future clinical trials for the development of targeted therapies and in identifying biomarkers to guide treatment decisions for the individual patient.

Malignancy in a retrospective cohort of 17 patients with Dermatomyositis or Polymyositis in southern Tunisia

INTRODUCTION

The prognosis of dermatomyositis (DM)/ polymyositis (PM) in adults is partly related to their association with neoplasia. The aim of our study was to report the epidemiologic, clinical, paraclinical, therapeutic and evolutionary aspects of DM associated with malignancy in patients from Sfax, south eastern of Tunisia.

METHODS

A retrospective cohort study of patients with DM or PM admitted in Dermatology and Internal Medicine Departments of Hedi Chaker University Hospital of Sfax between 1996 and 2015. Cases of DM or PM associated with malignancy were retained.

RESULTS

Seventeen cases (13.5%) of DM or PM associated with malignancy were noted. Fourteen patients had DM and 3 patients had PM. The Sex ratio M / F was 0.3 and the mean age at diagnosis was 56.5 years. In DM patients, malignancy preceded the myositis in 64.2% of cases. In PM patients, only one patient was known to have breast cancer and the myositis revealed the cancer for 2 others. Treatment consisted of corticosteroids associated with methotrexate in 4 cases. Outcome was fatal in 5 cases (29.4%), due to the underlying cancer in 3 cases. Swallowing disorders related to DM/PM were responsible for death in 2 cases.

CONCLUSION

There are no specific clinical or biological features in paraneoplastic DM. In our series, breast neoplasm represented the first cancer associated with DM. Cancers of nasopharynx, colon and urinary tract had the second position.

Disease Specific Autoantibodies in Idiopathic Inflammatory Myopathies

Idiopathic inflammatory myopathies represent still a diagnostic and therapeutic challenge in different disciplines including neurology, rheumatology, and dermatology. In recent years, the spectrum of idiopathic inflammatory myopathies has been significantly extended and the different manifestations were described in more detail leading to new classification criteria. A major breakthrough has also occurred with respect to new biomarkers especially with the characterization of new autoantibody-antigen systems, which can be separated in myositis specific antibodies and myositis associated antibodies. These markers are detectable in approximately 80% of patients and facilitate not only the diagnostic procedures, but provide also important information on stratification of patients with respect to organ involvement, risk of cancer and overall prognosis of disease. Therefore, it is not only of importance to know the significance of these markers and to be familiar with the optimal diagnostic tests, but also with potential limitations in detection. This article focuses mainly on antibodies which are specific for myositis providing an overview on the targeted antigens, the available detection procedures and clinical association. As major tasks for the near future, the need of an international standardization is discussed for detection methods of autoantibodies in idiopathic inflammatory myopathies. Furthermore, additional investigations are required to improve stratification of patients with idiopathic inflammatory myopathies according to their antibody profile with respect to response to different treatment options.

An overview of polymyositis and dermatomyositis

Polymyositis and dermatomyositis are inflammatory myopathies that differ in their clinical features, histopathology, response to treatment, and prognosis. Although their clinical pictures differ, they both present with symmetrical, proximal muscle weakness. Treatment relies mainly upon empirical use of corticosteroids and immunosuppressive agents. A deeper understanding of the molecular pathways that drive pathogenesis, careful phenotyping, and accurate disease classification will aid clinical research and development of more efficacious treatments. In this review we address the current knowledge of the epidemiology, clinical characteristics, diagnostic evaluation, classification, pathogenesis, treatment, and prognosis of polymyositis and dermatomyositis.

Paraneoplastic dermatomyositis related to a chondrosarcoma involving the cavernous sinus

Approximately one third of all cases of dermatomyositis may be associated with malignancy. We describe a patient with unexplained rash, joint pain, and muscle weakness, who subsequently developed a cavernous sinus syndrome due to a central nervous system chondrosarcoma. Discovery of this tumor and further dermatologic evaluation, including skin biopsy, resulted in diagnosis of paraneoplastic dermatomyositis due to cavernous sinus chondrosarcoma.

Paraneoplastic dermatomyositis: a study of 12 cases

INTRODUCTION AND OBJECTIVES

Adult dermatomyositis presents as a paraneoplastic syndrome in up to 25% of cases, but no clinical, histologic, or laboratory markers completely specific for paraneoplastic disease in dermatomyositis have been identified to date. Furthermore, studies on adult dermatomyositis do not usually report the frequency of cutaneous features of dermatomyositis in patients with associated cancer. Our aim was to review the characteristics of paraneoplastic dermatomyositis in patients seen at our hospital.

MATERIAL AND METHODS

We studied 12 cases of paraneoplastic dermatomyositis and recorded patient age and sex, associated cancer, time between onset of dermatomyositis and cancer, emergent cutaneous manifestations, muscle involvement, dysphagia, lung disease, and levels of creatine phosphokinase and circulating autoantibodies.

RESULTS

The mean age of the patients was 61 years and the 2 most common malignancies were ovarian cancer and bladder cancer. The mean time between the diagnosis of cancer and dermatomyositis was 7 months and in most cases, the cancer was diagnosed first. Seven patients had amyopathic dermatomyositis. The most common cutaneous signs were a violaceous photodistributed rash sparing the interscapular area and a heliotrope rash, followed by Gottron papules and cuticle involvement. Superficial cutaneous necrosis was observed in 3 cases. Myositis-specific autoantibodies were not detected in any of the 6 patients who underwent this test.

CONCLUSIONS

Paraneoplastic dermatomyositis is often amyopathic. There are no specific cutaneous markers for malignancy in dermatomyositis. Myositis-specific antibodies are not associated with paraneoplastic dermatomyositis.

[Usefulness of autoantibodies for the diagnosis of autoimmune myopathies]

INTRODUCTION

Idiopathic myopathies are a group of acquired muscular diseases considered as autoimmune disorders. Characteristic histopathologic features allow the classification into myositis (polymyositis, dermatomyositis, and inclusion body myositis) and immune-mediated necrotizing myopathies. But overlapping histological features may be observed between different idiopathic myopathies and even between acquired and genetic muscular diseases. In the group of idiopathic myopathies important discrepancies can be observed concerning extra-muscular involvement and prognosis.

STATE OF ART

The discovery of myositis-specific antibodies and myositis-associated antibodies has led to a serologic approach complementary to histological classification, because striking associations of myositis-specific antibodies with clinical features and survival were observed. Here we reviewed the myositis-specific antibodies including autoantibodies directed against the aminoacyl tRNA-synthetase enzymes, the Mi-2 protein and the signal recognition particle, and the main myositis-associated autoantibodies, that can be tested in clinical practice.

PERSPECTIVES

We will also focus on newly described dermatomyositis-associated antibodies (directed against: transcription intermediary factor 1 family proteins, small ubiquitin-like modifier activating enzyme, and melanoma differentiation-associated gene 5), and immune-mediated necrotizing myopathy-associated antibodies (directed against HMGcoA-reductase).

CONCLUSION

Myositis-specific antibodies and myositis-associated antibodies are useful for the diagnosis of forms of autoimmune myopathies with distinct clinical features. They may help to define patients into clinical syndromes with specific outcomes and thus influence treatment strategies.

Idiopathic inflammatory myopathies

Inflammatory myopathies are chronic, immune-mediated diseases characterised by progressive proximal muscle weakness. They encompass a variety of syndromes with protean manifestations. The diagnosis is based on Bohan and Peter's classification criteria, which nowadays seem to be obsolete. Our increasing knowledge about the risk factors, genetic susceptibility and immunological pathways in the disease mechanism leads to the establishment of a new, immunogenetically and serologically validated diagnostic criteria system. The treatment of idiopathic inflammatory myopathy is also a complex task requiring much experience. The aims of therapy are to increase muscle strength, prevent the development of contractures and manage the systemic manifestations of the disease. The most important one is the early detection of diseases and patients' immunological control in special centres. Using the basis therapeutic drugs temporary or permanent remission can be achieved, which improves patientsG' quality of life and functional ability. Rehabilitation and physiotherapy in the remission period may significantly improve the outcome of patients with functional disorders. The introduction of new biological therapies further allows us to control the myositis patients' state more effectively. The aim of this review is to summarise our knowledge about clinical symptoms, pathomechanism, as well as genetic, serologic and environmental risk factors. We would also like to present the way to diagnosis and the latest research about diagnostic criteria system, proposed outcome measures and therapeutic possibilities.

Dermatomyositis and chest radiography leading to the diagnosis of lung cancer and subsequent confusions in staging due to the presence of tuberculosis

This clinical scenario describes dermatomyositis as a presenting feature of carcinoma of the lung. However, the coincident existence of tuberculosis in the opposite lung gave rise to a false impression of contralateral lung metastasis and hence confusions with regard to staging ensued, which were clarified after further investigation confirmed a unilateral lung adenocarcinoma and contralateral tuberculosis. The patient was initiated on oral antiepidermal growth factor receptor therapy with erlotinib, as well as on multi-drug therapy for tuberculosis. This report intends to illustrate that paraneoplastic syndromes such as dermatomyositis can be the presenting feature of lung cancer, and also that the co-incident presence of carcinoma and tuberculosis can cause confusions with regard to staging and management.

Autoimmune myopathies: autoantibodies, phenotypes and pathogenesis

The different autoimmune myopathies-for example, dermatomyositis, polymyositis, and immune-mediated necrotizing myopathies (IMNM)-have unique muscle biopsy findings, but they also share specific clinical features, such as proximal muscle weakness and elevated serum levels of muscle enzymes. Furthermore, around 60% of patients with autoimmune myopathy have been shown to have a myositis-specific autoantibody, each of which is associated with a distinct clinical phenotype. The typical clinical presentations of the autoimmune myopathies are reviewed here, and the different myositis-specific autoantibodies, including the anti-synthetase antibodies, dermatomyositis-associated antibodies, and IMNM-associated antibodies, are discussed in detail. This Review also focuses on a newly recognized form of IMNM that is associated with statin use and the production of autoantibodies that recognize 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the pharmacological target of statins. The contribution of interferon signaling to the development of dermatomyositis and the potential link between malignancies and the initiation of autoimmune myopathies are also assessed.

Early-stage testicular cancer: a rare association with dermatomyositis

Dermatomyositis has a known association with malignancy. We report a case of dermatomyositis occurring in early-stage testicular cancer where the patient was in remission. It stresses the importance of considering testicular cancer as an association with dermatomyositis, as it is a potentially curable malignancy.

An 11-year Review of Dermatomyositis in Asian Patients

Introduction: Dermatomyositis (DM) is a multisystem inflammatory disease with a strong association with malignancy. We aimed to describe a series of Asian patients with DM and identify any significant clinical factors associated with malignancy. Materials and Methods: This was a retrospective review of a multi-racial cohort of 69 Asian patients diagnosed with DM over an 11-year period from 1996 to 2006. Results: Malignancy was detected in 15 out of 68 patients (22%), the most common of which was nasopharyngeal carcinoma (7 cases). Compared to the non-malignancy group, the malignancy-associated group was older and had more male patients. There were no statistically significant clinical, serological or laboratory factors associated with a higher risk of malignancy. Conclusion: This study highlights the importance of ongoing malignancy screening especially for nasopharyngeal carcinoma in Asian patients with DM. Key words: Malignancy, Myositis, Nasopharyngeal carcinoma, Photosensitivity

Paraneoplastic myopathy

PURPOSE OF REVIEW

It has been recognized for some time now, that compared with the normal population, patients with idiopathic inflammatory myopathies (IIM) live with an increased risk of developing malignancy. In the majority of these patients, cancer-associated myositis appears to have some paraneoplastic features. The aim of the present review is to describe new data that explain the connection between myositis and malignant diseases, as well as to highlight its value in the current management of these patients.

RECENT FINDINGS

Antigen expressions and patterns shared by regenerating muscle and cancers raise questions about whether myositis cases without clinically observable cancer may represent a fully successful antitumor immune response with bystander damage to regenerating muscle. The discovery of anti-155/140 autoantibody may aid in the better diagnosis of adult IIM patients with a higher risk of malignancy. It also may help the better understanding of paraneoplastic myositis.

SUMMARY

Cancer-associated myositis differs from primary myositis in many aspects. Prognosis and life-expectancy are determined by the underlying malignancy. Therefore, patient-specific examinations for detection of an underlying cancer are important in the management of patients. Recent clinical findings and new possibilities in immunoserological testing may result in the elaboration of an evidence-based recommendation for cancer screening programs in patients with IIM in the future.

Cancer-associated myositis and anti-p155 autoantibody in a series of 85 patients with idiopathic inflammatory myopathy

A new autoantibody against a 155-kDa protein has been described in patients with myositis. We conducted a study to determine the occurrence and types of cancer occurring in a cohort of patients with polymyositis (PM) or dermatomyositis (DM) and analyzed the value of this autoantibody as a serologic marker of cancer-associated myositis (CAM). Serum samples from all patients were examined by protein immunoprecipitation assays with HeLa cells to determine the presence of a 155-kDa protein band. HLA-DRB1 and DQA1 typing was performed by polymerase chain reaction-reverse sequence specific oligonucleotide. Statistical analyses were carried out with the Mann Whitney U and Fisher exact tests. Associations were determined using odds ratios (ORs) with 95% confidence intervals (CI). Eighty-five patients with myositis (20 PM and 65 DM) were included. CAM was detected in 16 patients (19%), 14 with DM. The shawl sign rash was significantly more frequent in patients with CAM than in those without (p < 0.01). Adenocarcinoma was the most frequent type of cancer (87.5%). Anti-p155 autoantibody was found in 1 of the 20 (5%) patients with PM and in 15 of the 65 (23%) patients with DM. A relationship between anti-p155 and CAM was found in DM patients (OR, 23; 95% CI, 5.23-101.2). The HLA-DQA1*0102 allele was not found in any of the anti-p155-positive patients. The prevalence of CAM in our cohort was 19%. Autoantibody against p155 was highly related to CAM and could be a reliable marker of cancer in patients with DM.