Identification of a novel autoantibody reactive with 155 and 140 kDa nuclear proteins in patients with dermatomyositis: an association with malignancy

Autoantibody evaluation in idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM), generally referred to as myositis is a heterogeneous group of diseases characterized by muscle inflammation and/or skin involvement, diverse extramuscular manifestations with variable risk for malignancy and response to treatment. Contemporary clinico-serologic categorization identifies 5 main clinical groups which can be further stratified based on age, specific clinical manifestations and/or risk for cancer. The serological biomarkers for this classification are generally known as myositis-specific (MSAs) and myositis-associated antibodies. Based on the use of these antibodies, IIM patients are classified into anti-synthetase syndrome, dermatomyositis, immune-mediated necrotizing myopathy, inclusion body myositis, and overlap myositis. The current classification criteria for IIM requires clinical findings, laboratory measurements, and histological findings of the muscles. However, the use MSAs and myositis-associated autoantibodies as an adjunct for disease evaluation is thought to provide a cost-effective personalized approach that may not only guide diagnosis but aid in stratification and/or prognosis of patients. This review provides a comprehensive overview of contemporary autoantibodies that are specific or associated myositis. In addition, it highlights possible pathways for the detection and interpretation of these antibodies with limitations for routine clinical use.

Advances of autoimmune rheumatic diseases related to malignant tumors

BACKGROUND

Malignant neoplasms are a well-recognized global public health concern, with significant impacts on human health and quality of life. The interplay between tumors and autoimmune rheumatic diseases is complex, and the resulting tumor-associated rheumatic diseases represent a rare and intricate group of conditions that occur in the context of malignant tumors. In addition, various rheumatic diseases can arise as a consequence of oncology treatment. These diseases present with intricate clinical manifestations and pathological features, often rendering them challenging to diagnose and impacting patients' quality of life. Despite this, they have yet to be fully recognized.

METHODS

This article presents a literature review of published original articles and review articles concerning paraneoplastic rheumatic syndromes and rheumatic diseases associated with cancer treatment. We conducted a comprehensive literature search in PubMed, Web of Science and Google Scholar databases, excluding duplicated and irrelevant studies. In cases of duplicated research, we selected articles with higher impact factors for the review.

RESULTS

This review focuses on the clinical features, diagnosis, and treatment of paraneoplastic rheumatic diseases, as well as the pathogenesis of these diseases. Additionally, we summarize the autoimmune rheumatic diseases associated with cancer treatment. Ultimately, the goal of this review is to enhance recognition and improve the management of autoimmune rheumatic diseases related to tumors.

A Case in Which Breast Cancer Developed at the Same Time As Dermatomyositis, and the Onset of New Cancer Was Able to Be Predicted by the Exacerbating Skin Symptoms and Parallel Increase in the Anti-TIF1-γ Antibody Levels

Dermatomyositis (DM) is an idiopathic inflammatory myopathy. The incidence of malignancy in DM patients is quite high. Anti-transcription intermediary factor 1-γ (anti-TIF1-γ) antibody is more prevalent in DM patients with malignancy than in those without malignancy. A 70-year-old woman developed hoarseness and difficulty swallowing. A physical examination revealed skin abnormalities. Breast cancer was found in her right breast. She was positive for anti-TIF1-γ antibody. Chemotherapy reduced the tumor size, decreased the anti-TIF1-γ antibody level, and improved her symptoms. About 2.5 years later, however, her skin symptoms worsened, and anti-TIF1-γ antibody levels increased again, and colorectal cancer was found. Treatment with endoscopic mucosal resection (EMR) improved her symptoms again. Our case suggests that the exacerbating skin symptoms and parallel increase in the anti-TIF1-γ antibody level led to the detection of a second cancer after treatment of the first cancer in this case of DM.

Systemic Inflammatory Disorders, Immunosuppressive Treatment and Increase Risk of Head and Neck Cancers-A Narrative Review of Potential Physiopathological and Biological Mechanisms

Head and neck cancers (HNCs) are known to present multiple factors likely to influence their development. This review aims to provide a comprehensive overview of the current scientific literature on the interplay between systemic inflammatory disorders, immunosuppressive treatments and their synergistic effect on HNC risk. Both cell-mediated and humoral-mediated systemic inflammatory disorders involve dysregulated immune responses and chronic inflammation and these inflammatory conditions have been associated with an increased risk of HNC development, primarily in the head and neck region. Likewise, the interaction between systemic inflammatory disorders and immunosuppressive treatments appears to amplify the risk of HNC development, as chronic inflammation fosters a tumor-promoting microenvironment, while immunosuppressive therapies further compromise immune surveillance and anti-tumor immune responses. Understanding the molecular and cellular mechanisms underlying this interaction is crucial for developing targeted prevention strategies and therapeutic interventions. Additionally, the emerging field of immunotherapy provides potential avenues for managing HNCs associated with systemic inflammatory disorders, but further research is needed to determine its efficacy and safety in this specific context. Future studies are warranted to elucidate the underlying mechanisms and optimize preventive strategies and therapeutic interventions.

Diagnosis and Management of Myositis-Associated Lung Disease

Although interstitial lung disease (ILD) is a leading cause of morbidity and mortality in patients with inflammatory myopathies, the current definition and diagnostic criteria of autoimmune myositis remain inadequate to capture the large proportion of patients with lung-dominant disease. As a result, these patients present unique diagnostic and treatment challenges for even the most experienced clinicians. This article highlights the emerging role of autoantibodies in the diagnosis, classification, and management of patients with ILD. We propose alternative nomenclature to facilitate research on this unique patient population. Additionally, evidence supporting the various therapies used in the treatment of myositis-associated ILD is reviewed. The classification and treatment of patients with myositis-associated ILD remains challenging. A standardized therapeutic approach to these patients is lacking, and prospective studies in the field are needed to determine optimal treatment regimens.

Paraneoplastic musculoskeletal disorders: review and update for radiologists

Rheumatic paraneoplastic syndromes are rare syndromes that occur at distant sites from the underlying tumor and may involve the bones, joints, fasciae, muscles, or vessels. In the absence of a known tumor, early recognition of a rheumatic syndrome as paraneoplastic permits dedicated work-up for, and potentially early treatment of an occult malignancy. Although there is a continuously growing list of paraneoplastic rheumatic disorders, not all of these disorders have a well-established association with a neoplastic process. The goals of this article are to review the clinical characteristics, diagnostic work-up, and imaging findings of well-documented rheumatic paraneoplastic disorders.

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.

Long-term risks of malignancy in myositis-specific antibody-positive idiopathic inflammatory myopathy

To identify the long-term risks of malignancy in patients with myositis-specific antibody (MSA)-positive idiopathic inflammatory myopathy (IIM). This retrospective cohort study included 216 IIM patients (aged > 18 years). Of these, 109 patients were positive for antibodies against anti-aminoacyl-tRNA synthetase (ARS), melanoma differentiation-associated gene 5 (MDA5), Mi-2, and transcriptional intermediary factor 1-γ (TIF1-γ). Age- and sex-matched standardized incidence ratios (SIRs) were calculated to compare the incidence of malignancy in IIM patients to that of the general population. The malignancy-free survival rate was estimated by Kaplan-Meier methods. Our study included 109 patients, 64 with anti-ARS, 28 with anti-MDA5, 9 with anti-Mi-2, and 8 with anti-TIF1-γ antibodies; 16 and 5 patients were diagnosed with a malignancy within 3 years before or after and within 4 to 10 years after their IIM onset, respectively. The SIRs of malignancy within 3 years of IIM onset for each MSA were calculated as follows: 2.12 (95% confidence interval [CI] 0.98-4.35) for anti-ARS, 1.87 (95% CI 0.48-4.97) for anti-MDA5, 2.11 (95% CI 0.11-13.69) for anti-Mi-2, and 9.30 (95% CI 2.98-25.58) for anti-TIF1-γ antibodies. The SIR at 4 to 10 years after IIM onset in patients with an anti-MDA5 antibody was 4.62 (95% CI 1.19-14.72); other MSAs did not have statistically significant SIRs. The long-term SIR of malignancy in patients with an anti-MDA5 antibody was 4.62 (95% CI 1.19-14.72), and the SIR among patients with an anti-TIF1-γ antibody within 3 years of IIM onset was 9.30 (95% CI 2.98-25.58). Screening for malignancies in patients with late phase of IIM and an anti-MDA5 antibody may be beneficial.

The association between clinical, subclinical features and autoantibody profile in Vietnamese dermatomyositis patients

There is still a lack of research in Vietnam on the autoantibody profile of dermatomyositis (DM) and its association with clinical and subclinical characteristics. Therefore, we conducted this study to investigate clinical and subclinical correlations with autoantibodies in DM patients. 72 DM patients at Vietnam National Hospital of Dermatology and Venereology (NHDV) from March 2019 to September 2021 were included in this cross-sectional study. Clinical manifestations and laboratory test results of the patients were obtained at the time of visit. Of these, 63 patients were tested for the presence of autoantibodies using an Immunoblot assay. Our findings show that the average age of patients was 41.7 years. The female-male ratio was 1.7:1. The most common skin and muscle manifestations were myalgia (79.2%), heliotrope rash (62.5%), shawl sign (61.1%), Gottron's sign (59.7%), muscle weakness (59.7%), Gottron's papule (52.8%), periungual telangiectasia (41.7%), V-sign (38.9%), poikiloderma (26.4%), periungual fissures (20.8%), Raynaud's phenomenon (15.3%). Among the 63 patients tested for autoantibodies, myositis-specific antibodies (MSAs) were found in 71.4% of the serum samples, and myositis-associated antibodies (MAAs) in 36.5%. Anti-TIF1γ antibody accounted for the highest percentage (28.6%), followed by anti-Ro52 (22.2%), anti-synthetase (17.5%), anti-Mi-2 and anti-MDA5 (both 14.3%). Anti-synthetase antibodies (ARS-Abs) showed a significant association with arthralgia, fever, and Raynaud's phenomenon, while anti-TIF1γ antibodies showed a strong association with V-sign and poikiloderma (p<0.05). Clinical features in dermatomyositis are heterogeneous. Our study results show some associations between clinical features and autoantibodies in patients with DM. The analysis of DM-related autoantibodies is clinically useful, will be essential for the approaches to diagnosis, and management of DM patients.

Characteristics of anti-transcriptional intermediary factor 1 gamma autoantibody-positive dermatomyositis patients in Singapore

Introduction: This study aimed to determine the clinical profile and outcome of anti-transcriptional intermediary factor 1 gamma autoantibody (anti-TIF1-γ Ab)-positive dermatomyositis patients and propose cancer screening programmes based on regional cancer trends. Method: Data on history, physical findings and investigations were collected using chart review on dermatomyositis patients seen at a tertiary hospital in Singapore from 1 January 2015 to 30 June 2021. Comparisons were made between anti-TIF1-γ Ab-positive and anti-TIF1-γ Ab-negative dermatomyositis. Results: Ninety-six dermatomyositis patients were analysed and 36 patients were positive for anti-TIF1-γ Ab. Anti-TIF1-γ Ab-positive patients had more frequent heliotrope rashes, shawl sign, periungual erythema, holster sign, Gottron’s papules, dysphagia and truncal weakness (P<0.05). They had less frequent interstitial lung disease, polyarthritis, cutaneous ulcers, palmar papules and mechanic’s hands (P<0.05). After 48 months of follow-up, a higher proportion of anti-TIF1-γ Ab-positive patients developed cancer compared with Ab-negative patients (63.9% versus 8.5%; odds ratio 19.1, 95% confidence interval 6.1–59.8; P<0.001). Nasopharyngeal carcinoma (NPC) and breast cancer were the most common malignancies, followed by bowel, lung and non-Hodgkin lymphoma. Most malignancies (78.3%) occurred within 13 months prior to, or 4 months after the onset of dermatomyositis. The mortality rate for anti-TIF1-γ Ab-positive patients was significantly higher than Ab-negative patients (36.1% vs 16.7%, P=0.031), and Kaplan-Meier survival estimates at 24 months were 66% and 89%, respectively (P=0.0153). Conclusion: These observational data support periodic screening of NPC and other malignancies in patients with anti-TIF1-γ Ab-positive dermatomyositis in Singapore. Keywords: Autoantibody, cancer, dermatomyositis, nasopharyngeal carcinoma, transcriptional intermediary factor 1 gamma

Autoantibodies and Cancer Association: the Case of Systemic Sclerosis and Dermatomyositis

Several rheumatic diseases have a perplexing association with cancer. Unraveling this mysterious connection is likely to provide deeper understanding regarding mechanisms governing the onset of both autoimmunity and cancer immunity, in addition to providing clinicians much needed guidance around whom and when to screen for occult malignancy. Systemic sclerosis (scleroderma) and dermatomyositis are two diseases in which the association with internal malignancy is well-described and can be considered as models from which to gain important insights that likely have broader applicability. The past 15 years have witnessed a striking acceleration in understanding how these two diseases are related to cancer emergence-an important crack in this inscrutable armor has been the discovery and characterization of disease-specific autoantigens that are closely tied with risk of cancer emergence. The best-described examples of this are antibodies against anti-RNA polymerase III (anti-POL3) and transcription intermediary factor 1-gamma (anti-TIF1γ). Patients with systemic sclerosis and cancer that are diagnosed within a short time interval of each other frequently have anti-POL3 antibodies. Antibodies against the minor spliceosome protein RNA-Binding Region Containing 3 (RNPC3) are also associated with increased cancer incidence in systemic sclerosis. Similarly, in the dermatomyositis spectrum, the majority of anti-TIF1γ-associated cancers are detected around the time of DM onset (most often within 1 year). Antibodies against Nuclear Matrix Protein 2 are also potentially associated with increased cancer emergence in dermatomyositis. The systemic sclerosis/anti-POL3 connection with close cancer onset led to the first experiments directly supporting the concept that rheumatic disease may in fact be a manifestation of cancer. It is now clear that studying these diseases through the lens of autoantibodies can reveal relationships and insights that would otherwise remain obscured. Extending these studies, new findings show that antibodies against RNA polymerase I large subunit are associated with protection against short interval cancers in anti-POL3-positive systemic sclerosis patients. These insights highlight the fact that autoantigen discovery related to cancer emergence remains an important priority; such new tools will enable the testing of specific hypotheses regarding mechanisms governing disease emergence and development of effective anti-tumor responses. Autoantibody phenotype will likely play an important role in the development of cancer screening guidelines that are critically needed by clinicians taking care of these patients. In this review, we will summarize the current state of knowledge regarding the different ways in which autoantibodies are connected with systemic sclerosis/dermatomyositis and malignancy and highlight potential paths forward.

Positive Autoantibody Is Associated with Malignancies in Patients with Idiopathic Interstitial Pneumonias

Various autoantibodies are associated with clinical outcomes in patients with idiopathic interstitial pneumonias (IIPs). We retrospectively analyzed the association between autoantibodies and malignancies in IIP patients. Comprehensive analyses of autoantibodies were performed using immunoprecipitation and enzyme-linked immunosorbent assays in 193 consecutive IIP patients. Cancer-related factors were analyzed using logistic regression analysis. In total, 22 of 193 patients (11.4%) with IIP had malignant disease. In univariate analysis, positivity for any autoantibody (odds ratio (OR), 3.1; 95% confidence interval (CI), 1.2-7.7; p = 0.017) and antinuclear antibody titer ≥1:320 (OR, 3.4; CI, 1.2-9.8; p = 0.024) were significantly associated with malignancies. Positive anti-aminoacyl tRNA synthetase (ARS) (OR, 3.7; CI, 0.88-15.5; p = 0.074) and anti-Ro52 antibody (OR, 3.2; CI, 0.93-11.2; p = 0.065) tended to be associated with malignancies. In multivariate analysis, independent risk factors were male sex (OR, 3.7; CI, 1.0-13.5; p = 0.029) and positivity for any autoantibody (OR, 3.9; CI, 1.5-10.1; p = 0.004) in model 1, and male sex (OR, 3.9; CI, 1.0-15.3; p = 0.049), antinuclear antibody titer ≥1:320 (OR, 4.2; CI, 1.4-13.3; p = 0.013), and positivity for anti-ARS antibody (OR, 6.5; CI, 1.2-34.1; p = 0.026) in model 2. Positivity for any autoantibody, antinuclear and anti-ARS antibodies, and male sex were independent risk factors for malignancies in IIP patients. Testing autoantibodies in IIP patients might help the early diagnosis of malignancies.

Prevalence of Myositis-Specific Autoantibodies and Myositis-Associated Autoantibodies in COVID-19 Patients: A Pilot Study and Literature Review

Coronavirus disease 2019 (COVID-19) infection has been linked to numerous autoimmune manifestations. Neither the mechanism nor the etiology of this association has been fully explored or elucidated. Prior studies have detected myositis in patients with proven COVID-19 infection, suggesting a relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the development of myositis. Studies have reported elevated levels of autoimmune antibodies, including myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs), in patients with COVID-19 infection, however the prevalence is not well documented. Our objective was to assess the prevalence of MSAs and MAAs in COVID-19 patients compared with unaffected subjects. Serum samples from 74 unvaccinated, polymerase chain reaction (PCR)-positive COVID-19 infected patients were compared with serum samples from 41 healthy, unaffected individuals. All serum samples were tested for MSA and MAA reactivity. Within the COVID-19-positive group, six (8.1%) patients exhibited MSA/MAA positivity, compared with only one (2.4%) individual from the control group. Although a higher prevalence of MSA/MAA positivity was observed within the COVID-19 infected group, the difference did not reach statistical significance (p=0.223). The autoantibodies detected in this study have a unique association with dermatomyositis and other inflammatory myopathies, and may play a role in COVID-19-associated myopathy. This article was previously presented as an abstract at Jacobs School of Medicine and Biomedical Sciences Research Day on June 3rd, 2022. 

Long-Term Outcomes and Prognosis Factors in Patients With Idiopathic Inflammatory Myopathies Based on Myositis-Specific Autoantibodies: A Single Cohort Study

OBJECTIVE

This study was undertaken to investigate the long-term survival rates and prognostic factors in patients with idiopathic inflammatory myopathies (IIMs) based on myositis-specific antibody (MSA) stratification.

METHODS

Exactly 628 patients with an IIM were included. Kaplan-Meier survival curves, univariate, and multivariate Cox regression were used to analyze the outcomes and risk factors.

RESULTS

The cumulative 1-, 5-, and 10-year survival rates for IIM patients overall were 91.4%, 82.8%, and 75.6%, respectively. The survival rate in the MSA subset was significantly different (P < 0.001). The 1- and 10-year survival rates in the anti-melanoma differentiation-associated protein 5 (anti-MDA-5)-positive subgroup were 79.5% and 58.5%, respectively, which were the lowest among all subgroups. The 10-year survival rate of anti-signal recognition particle (anti-SRP)-positive patients was the highest (96.4%). Independent risk factors that impacted the long-term prognosis for IIM patients included rapidly progressive interstitial lung disease (RP-ILD), malignancy, and elevated serum ferritin levels (hazard ratio [HR] 17.47, 20.36, and 9.15, respectively, P < 0.01), whereas disease duration was a protective factor (HR 0.27, P = 0.003). Among these subsets, the strongest independent risk factor for death in the anti-MDA-5-positive subgroup was RP-ILD (HR 3.4, P = 0.017). Malignancy was an independent risk factor in the anti-aminoacyl-tRNA synthetase antibody-positive, anti-transcription intermediary factor 1γ-positive, and MSA-negative subgroups (HR 46.69, 6.65, and 4.48, respectively; P < 0.001). RP-ILD was also a risk factor in the prognosis of individuals in the MSA-negative subgroup (HR 72.28, P < 0.001).

CONCLUSION

Despite favorable overall survival in patients with IIM, the anti-MDA-5-positive subgroup had the highest mortality rate among all MSA subgroups, highlighting the distinctive prognosis for patients with different MSAs. RP-ILD and malignancy are the most common causes of death in IIM patients.

An 8-Year-Old Boy With Prolonged Fever and Subcutaneous Nodules

An 8-year-old boy with asthma presented with prolonged fever, malaise, extremity weakness, polyarthralgias, malar rash, and subcutaneous nodules. Physical examination was remarkable for a faint malar rash, flesh-colored papules on the dorsal aspect of the fingers, arthritis of multiple joints in the hands, and subcutaneous nodules. The nodules were firm, nontender, and distributed over multiple extremities and the trunk. The patient was admitted to expedite workup. Initial laboratory test results revealed leukopenia, mild elevation of the aminotransferases, an elevated erythrocyte sedimentation rate, and normal level of creatine kinase. His echocardiogram was normal. Infectious disease studies were negative. Additional examination revealed dilated capillaries in his nail beds and bilateral hip weakness. MRI of his extremities was negative for myositis or calcification of the nodules. We obtained a biopsy of the subcutaneous nodules, and because the patient remained afebrile during the hospitalization, we discharged him from the hospital with outpatient follow-up. Our expert panel reviews the course of the patient's evaluation and investigation, as well as the implications of his diagnosis based on the tissue pathology from the nodule biopsy.

Serum levels of anti-transcriptional intermediary factor 1-γ autoantibody associated with the clinical, pathological characteristics and outcomes of patients with dermatomyositis

OBJECTIVE

To investigate the association of the serum levels of anti-transcriptional intermediary factor 1 (TIF1)-γ autoantibodies with the clinical and pathological characteristics, as well as the prognosis of adult patients with dermatomyositis (DM).

METHODS

Eighty-seven adult DM patients with anti-TIF1-γ autoantibodies positive screened by immunoblotting assay were enrolled in the study. The presence and levels of anti-TIF1-γ autoantibodies were examined through enzyme-linked immunosorbent assay (ELISA). Muscle biopsy specimens were obtained from 52 patients, and immunohistochemistry was performed to visualize major histocompatibility complex (MHC)-I, CD3, CD20 and C5b-9. Muscle biopsy scores and disease activity were evaluated.

RESULTS

A total of 80 patients were positive for anti-TIF1-γ autoantibodies confirmed by ELISA assay, including 30 cancer-associated myositis (CAM) and 50 non-CAM. Serum levels of anti-TIF1-γ autoantibodies did not significantly differ between the CAM and non-CAM groups. The levels of anti-TIF1-γ were associated with disease activity scores. A total of 63.9% of non-CAM patients displayed a classical DM pathological phenotype. Conversely, CAM patients presented with classical DM (25%), immune-mediated necrotizing myopathy (25%), non-specific myositis (32.3%), and normal (18%) phenotypes of muscle biopsy. Anti-TIF1-γ autoantibody levels were positively associated with muscle biopsy total scores, muscle fiber scores and inflammatory infiltration scores in the non-CAM patients but not in the CAM patients. The survival rate of CAM patients presenting with high anti-TIF1-γ autoantibody levels was lower than that of patients with low levels. However, no difference in survival rate was observed in the non-CAM group between high and low autoantibody levels.

CONCLUSION

The distinct associations of anti-TIF1-γ autoantibody levels with disease activity, muscle histopathology damage and outcome indicated that different pathogenesis might be involved in DM with or without cancer.

Clinical Characteristics of Anti-TIF-1γ Antibody-Positive Dermatomyositis Associated with Malignancy

We retrospectively analyzed the clinical and laboratory data of patients diagnosed with anti-transcriptional intermediary factor 1 (TIF-1γ) antibody-positive polymyositis (PM)/dermatomyositis (DM) to clarify the characteristics of this disease. We identified 14 patients with TIF-1γ antibody-positive DM (TIF-1γ DM), 47 with anti-aminoacyl-tRNA synthetase antibody (ARS)-positive PM/DM, and 24 with anti-melanoma differentiation-associated gene 5 antibody (MDA-5)-positive PM/DM treated at the Kurume University Hospital between 2002 and 2020. Patients with TIF-1γ DM were significantly older than the other two groups. Nine patients with TIF-1γ DM were female, thirteen patients had DM, and one had clinically amyopathic DM. Primary malignant lesions were lung (3), uterus (2), colon (2), breast (2), ovary (1), lymphoma (1), and unknown (2). Cutaneous manifestation and dysphagia were the most common symptoms in TIF-1γ DM. Erythema (9/14), the V-neck sign (8/14), heliotrope (9/14), and nailfold telangiectasia (14/14) were significantly more common in TIF-1γ DM. Furthermore, no patients with TIF-1γ DM had interstitial lung abnormality on high-resolution CT. In patients with TIF-1γ DM, the frequency of dysphagia and unusual erythema, particularly that which spreads from the trunk, and nailfold telangiectasia, were characteristic findings. In most patients with TIF-1γ DM, it is necessary to administer other immunosuppressive drugs along with glucocorticoids.

Myositis-specific Antibodies: Overview and Clinical Utilization

Purpose of review-To review autoantibodies associated with different subtypes of idiopathic inflammatory myopathy (IIM) and their clinical applications. IIM are a heterogenous group of autoimmune disorders characterized by muscle weakness, cutaneous features, and internal organ involvement. The diagnosis and classification, which is often challenging, is made using a combination of clinical features, muscle enzyme levels, imaging, and biopsy. The landmark discoveries of novel autoantibodies specific to IIM subtypes have been one of the greatest advancements in the field of myositis. The specificity of these autoantibodies has simplified the diagnostic algorithm of IIM with their heterogenous presentation and outdated the earlier diagnostic criteria. Myositis-specific antibodies (MSAs) have improved diagnostics, clinical phenotyping, and prognostic stratification of the subtypes of IIMs. Furthermore, the levels of certain MSAs correlate with disease activity and muscle enzyme levels such that titers may be able to be used to predict disease course and treatment response.

Immune responses to CCAR1 and other dermatomyositis autoantigens are associated with attenuated cancer emergence

BACKGROUND

The temporal clustering of a cancer diagnosis with dermatomyositis (DM) onset is strikingly associated with autoantibodies against transcriptional intermediary factor 1-γ (TIF1-γ). Nevertheless, many patients with anti–TIF1-γ antibodies never develop cancer. We investigated whether additional autoantibodies are found in anti–TIF1-γ–positive patients without cancer.

METHODS

Using a proteomic approach, we defined 10 previously undescribed autoantibody specificities in 5 index anti–TIF1-γ–positive DM patients without cancer. These were subsequently examined in discovery (n = 110) and validation (n = 142) cohorts of DM patients with anti–TIF1-γ autoantibodies.

RESULTS

We identified 10 potentially novel autoantibodies in anti–TIF1-γ–positive DM patients, 6 with frequencies ranging from 3% to 32% in 2 independent DM cohorts. Autoantibodies recognizing cell division cycle and apoptosis regulator protein 1 (CCAR1) were the most frequent, and were significantly negatively associated with contemporaneous cancer (discovery cohort OR 0.27 [95% CI 0.7–1.00], P = 0.050; validation cohort OR 0.13 [95% CI 0.03–0.59], P = 0.008). When cancer did emerge, it occurred significantly later in anti-CCAR1–positive compared with anti-CCAR1–negative patients (median time from DM onset 4.3 vs. 0.85 years, respectively; P = 0.006). Cancers that emerged were more likely to be localized (89% of anti-CCAR1–positive cancers presenting at stage 0 or 1 compared with 42% of patients without anti-CCAR1 antibodies, P = 0.02). As the number of additional autoantibody specificities increased in anti–TIF1-γ–positive DM patients, the frequency of cancer decreased (P < 0.001).

CONCLUSION

As the diversity of immune responses in anti–TIF1-γ DM patients increases, the likelihood of cancer emerging decreases. Our findings have important relevance for cancer risk stratification in DM patients and for understanding natural immune regulation of cancer in humans.

TRIAL REGISTRATION

Not applicable.

FUNDING SOURCES

The NIH, the Donald B. and Dorothy L. Stabler Foundation, and the Huayi and Siuling Zhang Discovery Fund.

Autoantibody Markers of Increased Risk of Malignancy in Patients with Dermatomyositis

Dermatomyositis is a chronic inflammatory disease involving the skin and muscles. It most commonly occurs in adults with preponderance in females, but pediatric occurrence is also possible. The risk of malignancy in adult patients with dermatomyositis was reported to be 4.66-fold higher compared to that in the general population. A significantly increased risk of malignancy was reported within the first 12 months following the diagnosis of dermatomyositis (standardized incidence ratio equaled 17). One of the characteristic laboratory findings associated with dermatomyositis is the presence of circulating autoantibodies which are classified into two subgroups: myositis-specific and myositis-associated autoantibodies. It was shown that specific types of antibodies might be associated with an increased risk of malignancy. Current literature data indicate that the strongest correlation with malignant diseases was reported in anti-TIF1-γ-positive patients who were at a 9.37-fold higher risk of cancer. A 3.68-fold increase in the risk of cancer was also reported among patients with anti-NXP2 antibodies. Malignant diseases were reported in 14-57% of patients with anti-SAE antibodies. The presence of other autoantibodies may also be associated with an increased risk of malignancy. These data indicate that patients with circulating anti-TIF1-γ, anti-NXP2, and anti-SAE should be very closely monitored for dermatomyositis-associated malignant comorbidities. The aim of this review is to summarize the current data regarding the link between malignancy and the presence of specific antibodies in patients with dermatomyositis.

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.

Clinical and laboratory parameters predicting cancer in dermatomyositis patients with anti-TIF1γ antibodies

BACKGROUND

Dermatomyositis (DM) is a chronic acquired autoimmune disorder strongly associated with cancer development. Until now, identifying predictive markers indicating a high risk of cancer has challenged clinicians. Although anti-TIF1γ antibody is a major serological indicator for cancer-associated DM, many anti-TIF1γ antibody-positive DM patients lack malignancy.

OBJECTIVES

To determine clinical and laboratory parameters that support cancer prediction in anti-TIF1γ antibody-positive DM patients.

METHODS

Clinical and laboratory data were collected from cancer-associated and unassociated DM patients with anti-TIF1γ antibodies. Serum cytokine concentrations were measured with a cytokine array assay. The values of inflammatory cytokines in cancer prognosis were determined with a receiver operating characteristic curve analysis.

RESULTS

The cancer group had a significantly higher frequency of males, older mean age and higher anti-TIF1γ antibody levels. Some inflammatory cytokines, particularly tumour necrosis factor (TNF) and TNF receptor superfamilies, had increased levels in sera that were correlated with myositis markers, cutaneous severity and DM disease activity. Moreover, these cytokines had an area under the curve (AUC) ≥0.8 and high sensitivity and specificity at their specific cut-off, even higher than anti-TIF1γ levels in cancer prediction in our DM patients.

CONCLUSIONS

Our results suggest a close pathophysiological relationship among myositis, cancer and skin involvements in DM patients with anti-TIF1γ antibodies and the potential clinical significance of anti-TIF1γ antibody levels in evaluating disease severity and prognosis in DM patients. Some inflammatory cytokines, particularly TNF and TNF receptor superfamilies including BAFF, sTNF-R1 and sTNF-R2, may support cancer prediction in DM patients with anti-TIF1γ antibodies.

Atezolizumab-associated Dermatomyositis in Advanced Small-cell Lung Carcinoma

Dermatomyositis is a rare immune-related adverse event caused by immune checkpoint inhibitors. We herein report a 75-year-old Japanese man with small-cell lung carcinoma who developed dermatomyositis after the administration of atezolizumab. He developed rashes on day 13 and myalgia and motor weakness on day 30 of the first administration of atezolizumab. Anti-transcriptional intermediary factor 1-gamma antibody was positive, and serum interleukin-6 levels were prominently elevated in the acute phase. Symptoms were improved by corticosteroid therapy. This is the first report of dermatomyositis associated with atezolizumab. Clinicians should be aware of the possibility of dermatomyositis after the administration of immune checkpoint inhibitors.

A systematic review and meta-analysis to inform cancer screening guidelines in idiopathic inflammatory myopathies

Objectives

To identify clinical factors associated with cancer risk in the idiopathic inflammatory myopathies (IIMs) and to systematically review the existing evidence related to cancer screening.

Methods

A systematic literature search was carried out on Medline, Embase and Scopus. Cancer risk within the IIM population (i.e. not compared with the general population) was expressed as risk ratios (RR) for binary variables and weighted mean differences (WMD) for continuous variables. Evidence relating to cancer screening practices in the IIMs were synthesized via narrative review.

Results

Sixty-nine studies were included in the meta-analysis. DM subtype (RR 2.21), older age (WMD 11.19), male sex (RR 1.53), dysphagia (RR 2.09), cutaneous ulceration (RR 2.73) and anti-transcriptional intermediary factor-1 gamma positivity (RR 4.66) were identified as being associated with significantly increased risk of cancer. PM (RR 0.49) and clinically amyopathic DM (RR 0.44) subtypes, Raynaud’s phenomenon (RR 0.61), interstitial lung disease (RR 0.49), very high serum creatine kinase (WMD −1189.96) or lactate dehydrogenase (WMD −336.52) levels, and anti-Jo1 (RR 0.45) or anti-EJ (RR 0.17) positivity were identified as being associated with significantly reduced risk of cancer. Nine studies relating to IIM-specific cancer screening were included. CT scanning of the thorax, abdomen and pelvis appeared to be effective in identifying underlying asymptomatic cancers.

Conclusion

Cancer risk factors should be evaluated in patients with IIM for risk stratification. Screening evidence is limited but CT scanning could be useful. Prospective studies and consensus guidelines are needed to establish cancer screening strategies in IIM patients.

Clinical Features and Cutaneous Manifestations of Juvenile and Adult Patients of Dermatomyositis Associated with Myositis-Specific Autoantibodies

Dermatomyositis is one of the idiopathic inflammatory myopathies, which is characterized with specific skin manifestations, and considered as an autoimmune disease. Dermatomyositis is a heterogeneous disorder with various presences, severities and characteristics of myositis, dermatitis, and interstitial lung disease. Our and others' data showed that myositis-specific autoantibodies have been associated with distinct clinical features. This article reviewed the epidemiology and characteristic clinical features of the different types of antibody-associated dermatomyositis in adult and juvenile patients, which include the severity of myopathy, the potential complication of interstitial lung disease, potential association with malignancies, and characteristic cutaneous manifestations.

A. R. ENS, Wada Y, Abdul Rahman Z, Ahmad S, Mohamud R, Mat Lazim N, Yean CY. Prevalence of Nasopharyngeal Carcinoma in Patients with Dermatomyositis: A Systematic Review and Meta-Analysis

Simple Summary

This first systematic review and meta-analysis on the prevalence of nasopharyngeal carcinoma in patients suffering dermatomyositis was necessitated by the absence of a true and reliable prevalence estimate necessary to adequately inform medical preparedness and decisions. Following a careful review of literature and data analyses, a prevalence of 3.3% was found. It is hoped that a clear knowledge of the actual prevalence of nasopharyngeal carcinoma in dermatomyositis patients would not only help sensitize clinicians and patients about the frequency of these disease conditions but would also enhance the adoption of precautions essential to mitigate their co-occurrence in patients.

Abstract

For more than 50 years, nasopharyngeal carcinoma (NPC) has been associated with dermatomyositis (DM), a rare idiopathic inflammatory disorder that mainly affects the skin and muscles. Although the association between these rare diseases is well-documented, the actual prevalence of NPC in DM patients remains unknown. Here, a systematic review and meta-analysis of published data was conducted in accordance with the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Electronic databases including PubMed, Scopus, ScienceDirect, and Google Scholar were searched without year or language restrictions for studies reporting the occurrence of NPC in DM patients. The study protocol was lodged with PROSPERO (CRD42021225335). A total of 95 studies covering 303 cases of NPC among 16,010 DM patients was included. Summary estimates were calculated using the random-effects model. The pooled prevalence of NPC in DM was 3.3% (95% CI, 2.5–4.3). When stratified according to study location, higher prevalence estimates were obtained for Hong Kong (36.5%), Malaysia (27.7%), and Singapore (11.9%). There was a predominance of cases among male DM patients compared with females, and most patients were aged 40 and above. Many of the NPC cases were found to be diagnosed after the diagnosis of DM. It is therefore pertinent to screen for NPC in DM patients, especially among older DM patients in the Asian region.

Immune response to dermatomyositis-specific autoantigen, transcriptional intermediary factor 1γ can result in experimental myositis

OBJECTIVES

To investigate whether autoimmunity to transcriptional intermediary factor 1 (TIF1)γ, a ubiquitous nuclear autoantigen for myositis-specific autoantibodies detected in patients with dermatomyositis (DM) is pathogenetic for inflammatory myopathy.

METHODS

Wild-type, β₂-microglobulin-null, perforin-null, Igμ-null and interferon α/β receptor (IFNAR)-null mice were immunised with recombinant human TIF1γ whole protein. A thymidine incorporation assay was performed using lymph node T cells from TIF1γ-immunised mice. Plasma was analysed using immunoprecipitation followed by western blot analysis and enzyme-linked immunosorbent assays. Femoral muscles were histologically and immunohistochemically evaluated. CD8⁺ or CD4⁺ T cells isolated from lymph node T cells or IgG purified from plasma were adoptively transferred to naïve mice. TIF1γ-immunised mice were treated with anti-CD8 depleting antibody and a Janus kinase inhibitor, tofacitinib.

RESULTS

Immunisation with TIF1γ-induced experimental myositis presenting with necrosis/atrophy of muscle fibres accompanied by CD8⁺ T cell infiltration successfully in wild-type mice, in which TIF1γ-specific T cells and antihuman and murine TIF1γ IgG antibodies were detected. The incidence and severity of myositis were significantly lower in β₂-microglobulin-null, perforin-null, CD8-depleted or IFNAR-null mice, while Igμ-null mice developed myositis normally. Adoptive transfer of CD8⁺ T cells induced myositis in recipients, while transfer of CD4⁺ T cells or IgG did not. Treatment with tofacitinib inhibited TIF1γ-induced myositis.

CONCLUSIONS

Here we show that TIF1γ is immunogenic enough to cause experimental myositis, in which CD8⁺ T cells and type I interferons, but not CD4⁺ T cells, B cells or antibodies, are required. This murine model would be a tool for understanding the pathologies of DM.

Anti-TIF1γ antibody-positive dermatomyositis associated with durvalumab administration in a patient with lung and oesophageal cancers

We report a case of anti-transcriptional intermediary factor 1γ (TIF1γ) antibody-positive dermatomyositis following durvalumab treatment. The patient was successfully treated with pulse steroid therapy, high-dose intravenous immunoglobulin (IVIg), and tacrolimus. Durvalumab may induce dermatomyositis, and early diagnosis and aggressive therapy are crucial to prevent severe dermatomyositis, which is potentially treatable.

Dermatomyositis autoantibodies: how can we maximize utility?

The past 15 years has seen significant advances in the characterization of myositis-specific autoantibodies (MSAs) and their associated phenotypes in patients with dermatomyositis (DM). As more careful studies are performed, it is clear that unique combinations of clinical and pathological phenotypes are associated with each MSA, despite the fact that there is considerable heterogeneity within antibody classes as well as overlap across the groups. Because risk for interstitial lung disease (ILD), internal malignancy, adverse disease trajectory, and, potentially response to therapy differ by DM MSA group, a deeper understanding of MSAs and validation and standardization of assays used for detection are critical for optimizing diagnosis and treatment. Like any test, the diagnostic sensitivity and specificity of assays for various MSAs is not perfect. Currently tests for MSAs are helpful at minimum for a clinician to assess relative risk or contribute to diagnosis and perhaps counsel the appropriate patient about what to expect. With international standardization and larger studies it is likely that more antibody tests will make their way into formal schemata for diagnosis and actionable risk assessment in DM. In this review, we summarize key considerations for interpreting the clinical and pathologic associations with MSA in DM and identify critical gaps in knowledge and practice that will maximize their clinical utility and utility for understanding disease pathogenesis.

Anti-TIF-1γ Antibody Detection Using a Commercial Kit vs In-House Immunoblot: Usefulness in Clinical Practice

Objectives

Anti-TIF-1γ autoantibody detection is important for cancer screening in patients with dermatomyositis. The gold standard for anti-TIF-1γ detection, immunoprecipitation, is only available from a few specialized laboratories worldwide, so commercial ELISA/immunoblot tests have emerged in recent years. To analyze their usefulness in diagnosing cancer-associated dermatomyositis, we compared Euroimmun Euroline profile with our previously validated in-house immunoblot assay with human recombinant TIF-1γ.

Methods

We included 308 adult patients from Hospital de la Santa Creu I Sant Pau and Vall Hebrón Hospital (Barcelona, Spain) tested for anti-TIF-1γ autoantibodies using the Euroline profile and an in-house immunoblot assay.

Results

A total of 27 anti-TIF-1γ were detected by the Euroline and 12 by the in-house assay. Fair agreement was observed between Euroline and the in-house immunoblot Cohen’s kappa 0.3163. Expected prevalence of anti-TIF-1γ autoantibodies was observed for the two methods for dermatomyositis and undifferentiated connective tissue diseases, but unexpectedly high prevalence of anti-TIF-1γ autoantibodies was detected by Euroline compared to the in-house immunoblot for other diseases (16.5% Euroline vs 0.8% in-house immunoblot, p<0.01). The in-house IB compared to Euroline more reliably detected cancer in patients with DM with anti-TIF-1γ antibodies (p=0.0014 vs p=0.0502 for in-house immunoblot vs Euroline).

Conclusion

We recommend using a second validated method to confirm Euroline-detected anti-TIF-1γ antibodies when the dermatomyositis diagnosis is not definitive. Furthermore, in the context of definite DM diagnosis with negative anti-TIF-1γ antibodies by Euroline and no other myositis specific antibody, is also recommendable to confirm by a second validated method.

Paraneoplastic syndromes in cholangiocarcinoma

Paraneoplastic syndromes are the symptoms or signs which result from damage to tissues that are distant from the site of malignancy, due to complex interactions between the body’s immune system and malignant neoplasm. Cholangiocarcinoma (CCA) is an aggressive epithelial malignancy of hepatobiliary tree and it is found to be associated with various paraneoplastic syndromes. These syndromes can present as dermatological, neurological, renal, hematological, or multi-systemic manifestations. Clinical suspicion and timely recognition of these syndromes can lead to early diagnosis of covert malignancies like CCA. The management plan remains the removal of the underlying cause which in this case is CCA.

Paraneoplastic Necrotizing Myopathy Post Lumpectomy and Chemotherapy for Early Breast Cancer

Our case report describes a 60-year-old female patient with a past medical history of Stage IB breast cancer, status post lumpectomy and adjuvant chemotherapy, admitted to our hospital with the chief complaints of fever, myalgia, and muscle weakness. A physical exam revealed proximal muscle weakness and a facial rash. A full workup was done, and the muscle biopsy showed evidence of a necrotizing myopathic process, which confirmed our diagnosis. This led to a diagnosis of necrotizing myopathy, deemed to be paraneoplastic after other possible differentials were ruled out. The patient showed improvement after a five-day course of intravenous immunoglobulin (IVIG) and high-dose steroids. Necrotizing myopathy, as a paraneoplastic process, has been scarcely described. In the context of our case, we review the characteristics and relevant existing literature about paraneoplastic necrotizing myopathy as well as emphasize the need to include it as a differential in the setting of malignancy.

Clinical features of anti-transcription intermediary factor 1γ (TIF1γ)-positive dermatomyositis with internal malignancy and investigation of the involvement of TIF1γ expression in tumors in the pathogenesis of cancer-associated dermatomyositis

Anti-transcription intermediary factor 1γ (anti-TIF1γ) antibody (Ab) is significantly associated with internal malignancies in adult patients with dermatomyositis (DM). Although pathogenesis of cancer-associated DM is unknown, TIF1γ overexpression in tumors has been considered to be critical for the development of DM. The objective of this study was to investigate clinical characteristics of patients with anti-TIF1γ Ab-positive DM and elucidate risk factors that are potentially associated with internal malignancy. In addition, we compared the expression of TIF1γ in tumor tissues of patients with anti-TIF1γ Ab-positive DM, anti-TIF1γ Ab-negative DM and without DM in order to investigate the pathogenesis of cancer-associated DM. We analyzed 77 Japanese patients with DM, and found 19 patients to be positive for anti-TIF1γ Ab. Patients with anti-TIF1γ Ab-positive DM were older and presented heliotrope rash and flagellate erythema more frequently than patients without anti-TIF1γ Ab (P < 0.05). Interstitial lung disease (ILD) and rapidly progressive ILD, as well as palmar violaceous erythema, were less frequent in patients with anti-TIF1γ Ab than in patients without. Furthermore, internal malignancy and dysphagia were significantly more frequent in the anti-TIF1γ Ab-positive group (P < 0.01). Male sex and dysphagia were significantly associated with internal malignancy in patients with anti-TIF1γ Ab-positive DM (P < 0.01 and <0.05, respectively). Using immunohistochemistry, we examined the TIF1γ expression in tumors of 11 patients with cancer-associated DM (anti-TIF1γ Ab-positive, nine; anti-TIF1γ Ab-negative, two) and 25 patients without DM. TIF1γ was highly expressed in all tumors, and there was no significant difference in TIF1γ expression between patients with and without DM. Furthermore, TIF1γ expressions in tumors were similar irrespective of the presence of anti-TIF1γ Ab. These results suggest that anti-TIF1γ antibody may not be simply induced by overexpression of TIF1γ in tumors in patients with DM, but that other mechanisms may exist.

Transcriptional intermediary factor 1 (TIF1) and anti-TIF1γ antibody-positive dermatomyositis

Recently, great advancements have been made towards understanding the mechanisms underlying dermatomyositis (DM). Many novel autoantibodies, such as anti-MDA5, anti-TIF1γ, anti-NXP2, and anti-SAE, have been reported to be involved in DM. DM is now classified based on these myositis-specific autoantibodies. Anti-TIF1γ antibodies are closely associated with juvenile DM and adult cancer-associated DM. Anti-TIF1γ antibody-positive DM tends to present severe cutaneous manifestations, mild myositis, and dysphagia. TIF1γ (also known as TRIM33) plays a role in transcriptional elongation, DNA repair, differentiation of cells, embryonic development, and mitosis. Moreover, TIF1γ has been shown to suppress various tumors via the TGF-β/Smad and the Wnt/β-Catenin signaling pathways. In this review, we explore the relationship between TIF1γ, cancer, and DM. We also discuss the pathogenesis of anti-TIF1γ antibody-positive DM.

Presence of anti-transcriptional intermediary factor-1 gamma antibodies in a dermatomyositis patient with retroperitoneal cancer of unknown primary site

A 71-year-old woman with dermatomyositis (DM) received glucocorticoid steroid (GCS) and tacrolimus treatment. Relapse of skin symptoms was observed after tapering the GCS dose, and the patient tested positive for anti-transcriptional intermediary factor-1 gamma (TIF1-γ) antibody. Examinations for malignancy were repeatedly performed. However, no obvious findings indicative of a tumour were observed. Two years after, a retroperitoneal tumour was detected and pathologically diagnosed as poorly differentiated adenocarcinoma. The patient developed intestinal and biliary obstruction and eventually died of sepsis. Herein, we report the presence of anti-TIF1-γ antibodies in a DM patient with cancer of unknown primary site.

Dermatomyositis: An Update on Diagnosis and Treatment

Dermatomyositis is a rare inflammatory disease with characteristic cutaneous findings and varying amounts of systemic involvement. Patients may present with skin disease alone, have concomitant muscle disease, or have extracutaneous manifestations such as pulmonary disease or an associated malignancy. Given such diverse presentations, dermatomyositis is both a diagnostic and therapeutic challenge. However, a prompt diagnosis is of utmost importance to institute adequate therapy and screen patients for an associated malignancy. Dermatologists should play a crucial role in the diagnosis and management of patients with dermatomyositis as cutaneous disease tends to be chronic, negatively impact quality of life, and be more recalcitrant to therapy. In this review, we discuss diagnosis, with a focus on myositis-specific antibodies and their associated phenotypes. We also review therapies available for this often refractory skin disease.

Analysis of myositis autoantibodies in Chinese patients with cancer-associated myositis

Background

Cancer‐associated myositis (CAM) has poor prognosis and causes higher mortality. In general, myositis‐specific autoantibodies (MSAs) and myositis‐associated autoantibodies (MAAs) have been shown to be useful biomarkers for its diagnosis.

Methods

In the present study, focus was given in assessing the presence, prevalence, and diagnostic values of myositis autoantibodies in Chinese patients diagnosed with CAM. The sera collected from 49 CAM patients, 108 dermatomyositis/polymyositis (DM/PM) patients without cancer, 105 disease controls, and 60 healthy controls were detected for the presence of 16 autoantigens (Jo‐1, OJ, EJ, PL‐7, PL‐12, MDA5, TIF1γ, Mi‐2α, Mi‐2β, SAE1, NXP2, SRP, Ku, PM‐Scl75, PM‐Scl100, and Ro‐52) using a commercial Euroline assay.

Results

The frequency of anti‐TIF1γ was significantly higher in CAM patients than in DM/PM patients without cancer (46.9% vs 14.8%, P < .001). Importantly, the sensitivity and specificity for this MSA were 46.9% and 85.2%, respectively. These helped to differentiate CAM patients from DM/PM patients without cancer. However, there was no difference in other MSAs and MAAs between CAM and DM/PM patients without cancer.

Conclusion

The present study indicates that anti‐TIF1γ levels can serve as important biomarkers for CAM diagnosis and help in distinguishing between CAM and DM/PM patients without cancer.

Combined immunosuppressive therapy provides favorable prognosis and increased risk of cytomegalovirus reactivation in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab) is myositis-specific autoantibody associated with rapidly progressive interstitial lung disease (ILD) and poor prognosis. In this retrospective observational study, we aimed to verify the efficacy and safety of introducing combined immunosuppressive therapy for anti-MDA5 Ab-positive dermatomyositis (DM) from their early stage. We recruited all Japanese patients diagnosed with DM in our clinic between January 2011 and October 2018, who had anti-MDA5 Ab, anti-aminoacyl transfer RNA synthetase Ab or anti-transcriptional intermediary factor 1-γ Ab. Combined immunosuppressive therapy was defined as combination of systemic corticosteroids, i.v. cyclophosphamide and tacrolimus. The difference of clinical features among the three groups was analyzed by multiple comparison analysis. The longitudinal change of the measurements from baseline was examined by Wilcoxon signed-rank test. Association between therapeutic regimens and adverse events was examined by logistic regression analysis. As a result, combined immunosuppressive therapy was most frequently used in the anti-MDA5 Ab-positive group, which significantly improved their forced vital capacity of the lung. Interval time since initial visit until starting treatment was the shortest in the anti-MDA5 Ab-positive group. There was no significant difference in the incidence of death and recurrence among the three groups. Cytomegalovirus reactivation was most common in the anti-MDA5 Ab-positive group, associated with combined immunosuppressive therapy. Collectively, early introduction of combined immunosuppressive therapy was effective for DM patients with anti-MDA5 Ab. At the same time, clinicians should be aware of the risk of cytomegalovirus reactivation during the treatment.

Autoantibody Biomarkers in Rheumatic Diseases

Autoantibodies encountered in patients with systemic rheumatic diseases bear clinical significance as a biomarker to help or predict diagnosis, clinical phenotypes, prognosis, and treatment decision-making. Furthermore, evidence has accumulated regarding the active involvement of disease-specific or disease-associated autoantibodies in the pathogenic process beyond simple association with the disease, and such knowledge has become essential for us to better understand the clinical value of autoantibodies as a biomarker. This review will focus on the current update on the autoantibodies of four rheumatic diseases (rheumatoid arthritis, myositis, systemic sclerosis, and anti-neutrophil cytoplasmic antibody associated vasculitis) where there has been a tremendous progress in our understanding on their biological effects and clinical use.

The temporal relationship between cancer and adult onset anti-transcriptional intermediary factor 1 antibody-positive dermatomyositis

Objectives

To characterize the 10 year relationship between anti-transcriptional intermediary factor 1 antibody (anti-TIF1-Ab) positivity and cancer onset in a large UK-based adult DM cohort.

Methods

Data from anti-TIF1-Ab-positive/-negative adults with verified diagnoses of DM from the UK Myositis Network register were analysed. Each patient was followed up until they developed cancer. Kaplan–Meier methods and Cox proportional hazard modelling were employed to estimate the cumulative cancer incidence.

Results

Data from 263 DM cases were analysed, with a total of 3252 person-years and a median 11 years of follow-up; 55 (21%) DM cases were anti-TIF1-Ab positive. After 10 years of follow-up, a higher proportion of anti-TIF1-Ab-positive cases developed cancer compared with anti-TIF1-Ab-negative cases: 38% vs 15% [hazard ratio 3.4 (95% CI 2.2, 5.4)]. All the detected malignancy cases in the anti-TIF1-Ab-positive cohort occurred between 3 years prior to and 2.5 years after DM onset. No cancer cases were detected within the following 7.5 years in this group, whereas cancers were detected during this period in the anti-TIF1-Ab-negative cases. Ovarian cancer was more common in the anti-TIF1-Ab-positive vs -negative cohort: 19% vs 2%, respectively (P < 0.05). No anti-TIF1-Ab-positive case <39 years of age developed cancer, compared with 21 (53%) of those ≥39 years of age.

Conclusion

Anti-TIF1-Ab-positive-associated malignancy occurs exclusively within the 3 year period on either side of DM onset, the risk being highest in those ≥39 years of age. Cancer types differ according to anti-TIF1-Ab status, and this may warrant specific cancer screening approaches.

Cutaneous manifestations of dermatomyositis characterized by myositis-specific autoantibodies

Dermatomyositis (DM) is an inflammatory myopathy with characteristic skin manifestations, the pathologies of which are considered autoimmune diseases. DM is a heterogeneous disorder with various phenotypes, including myositis, dermatitis, and interstitial lung disease (ILD). Recently identified myositis-specific autoantibodies have been associated with distinct clinical features. For example, anti-melanoma differentiation-associated protein 5 antibodies have a high specificity for clinically amyopathic DM presenting rapidly progressive ILD. Furthermore, anti-transcriptional intermediary factor 1γ antibodies found in patients with juvenile and adult DM are closely correlated with malignancies, especially in elderly patients. Finally, patients with anti-aminoacyl-transfer RNA synthetase antibodies share characteristic clinical symptoms, including myositis, ILD, arthritis/arthralgia, Raynaud’s phenomenon, and fever; thus, the term “anti-synthetase syndrome” is also used. With a focus on the characteristic cutaneous manifestations in each subgroup classified according to myositis-specific autoantibodies, we introduce the findings of previous reports, including our recent analysis indicating that skin eruptions can be histopathologically classified into myositis-specific autoantibody-associated subgroups and used to determine the systemic pathologies of the different types of antibody-associated DM.