Amyopathic Dermatomyositis: Definitions, Diagnosis, and Management

Clinical characteristics and symptom progression of dermatomyositis subtypes: A retrospective analysis of a prospective database

BACKGROUND

Disease characteristics of classic dermatomyositis (DM) and clinically amyopathic DM (CADM) are well established, but there exists limited knowledge on the disease progression of these subtypes.

OBJECTIVE

The objective of this study was to longitudinally track and characterize classic DM and CADM patients who experience changes in disease presentation.

METHODS

We conducted a retrospective review of prospectively collected data on 269 DM patients from a longitudinal database.

RESULTS

A total of 51% of the patients had classic DM and 49% had CADM. Forty percent of the classic DM patients became postmyopathic (PmDM). Median Cutaneous Dermatomyositis Disease Area and Severity Index activity (CDASI-A) score was lower in PmDM patients than in classic DM patients (13.0 vs 16.0), but 45% of the PmDM patients had CDASI-A scores > 14. Five percent of the CADM patients developed muscle involvement. Compared with CADM patients, those who developed muscle symptoms had milder skin disease before subtype conversion (median CDASI-A 12.0 vs 16.0) and at subtype conversion (median CDASI-A 9.0 vs 16.0).

LIMITATIONS

This was a retrospective study conducted at a single tertiary-care dermatology clinic.

CONCLUSIONS

Forty percent of the classic DM patients became PmDM. The majority continue with muscle disease, and many continue to have moderate/severe skin disease. CADM has a low risk of progressing to muscle disease, with the extent of skin disease as a potential predictive factor.

Prognostic analysis of MDA5-associated clinically amyopathic dermatomyositis with interstitial lung disease

OBJECTIVE

To investigate the prognostic factors of patients with anti-melanoma differentiation-associated gene 5 (MDA5) positive clinically amyopathic dermatomyositis (CADM) and interstitial lung disease (ILD).

METHODS

A retrospective analysis was conducted on clinical data of 125 patients with anti-MDA5 + CADM-ILD collected from 10 branches in eastern China between December 2014 and December 2022. Prognostic factors were analyzed using χ2 test, Log-rank test, COX and logistic regression analysis.

RESULTS

In this cohort, 125 anti-MDA5 + CADM-ILD patients exhibited a rapidly progressive interstitial lung disease (RPILD) incidence of 37.6%, and an overall mortality rate of 24.8%. One patient was lost to follow-up. After diagnosis of RPILD, a mortality rate of 53.2% occurred in patients died within 3 months, and that of 5.6% appeared in those who survived for more than 3 months. Multiple factor analysis revealed that C-reactive protein (CRP) ≥ 10 mg/L (p = 0.01) and recombinant human tripartite motif containing 21 (Ro52) (+) (p = 0.003) were associated with a higher risk of RPILD in anti-MDA5 + CADM-ILD patients; CRP ≥ 10 mg/L (p = 0.018) and the presence of RPILD (p = 0.003) were identified as the factors influencing survival time in these patients, while arthritis was the protective factor (p = 0.016).

CONCLUSION

Patients with anti-MDA5 + CADM-ILD will have a higher mortality rate, and the initial 3 months after diagnosis of RPILD is considered the risk window for the dismal prognosis. Patients with CRP ≥ 10 mg/L, Ro52 (+) and RPILD may be related to a shorter survival time, while patients complicated with arthritis may present with relatively mild conditions.

A 30-year-old female with dermatomyositis without high elevation of muscle enzymes: a rare case report from Syria

Introduction and importance

Dermatomyositis (DM), sometimes referred to as inflammatory and degenerative changes in the skin and muscles, is a rare autoimmune disorder. DM is distinguished by myopathic disease, symmetrical proximal muscle weakness, and increased creatine kinase (CK).

Case presentation

A 30-year-old-female presented to the department of dermatology with a history of chronic right hand pain spreading to the shoulder, severe tachycardia, and dyspenia that increased during routine tasks like using the bathroom. What makes this case unique is that the CPK developed without doubling, and the final concentration was 207 ng/ml. Other common clinical symptoms include amyopathic/hypomyopathic muscle involvement and DM-specific rash (Gottron's papules, heliotrope rash), and these manifestations were in our patients. Sun protection, topical treatment with corticosteroids and/or calcineurin inhibitors, and systemic medication should be utilized for all individuals with nonvasculopathic disease. In our case, the patient stopped using azathioprine and began taking methotrexate.

Clinical discussion

Sun protection, topical therapy with corticosteroids and/or calcineurin inhibitors, and systemic medication should be utilized in layers for all individuals with nonvasculopathic illnesses. Mycophenolat Mofetil is beneficial in treating refractory illnesses as well as individuals with interstitial lung disease or substantial skin disease.

Conclusion

Even if test findings are not conclusive, dermatomyositis should always be considered when muscular weakness manifests. It's important to distinguish the disorder from connective tissue diseases like lupus erythematosus. In fact, to correctly diagnose DM, if there are any doubts, a muscle biopsy is required.

Dermatomyositis: Practical Guidance and Unmet Needs

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

Clinically amyopathic dermatomyositis associated with cutaneous ulcerations: a case-based review

Introduction and importance

Dermatomyositis (DM) is an autoimmune myopathy primarily affecting both muscles and skin. When muscle weakness is not clinically apparent, but characteristic skin lesions are present, the condition is referred to as clinically amyopathic dermatomyositis (CADM).

Case presentation

The authors present the case of a 52-year-old female with a typical DM rash, interstitial pneumonia, and multiple skin ulcers. The skin biopsy was consistent with DM, and there were no signs of muscle involvement. Myositis-related and myositis-specific autoantibodies were also negative. Significant improvement was not observed until the patient received successive monthly pulses of methylprednisolone and the introduction of methotrexate. This treatment regimen allowed for the complete tapering of prednisone and resulted in sustained disease control.

Clinical discussion

In addition to the case presentation, a narrative literature review was conducted using the MEDLINE database, and an evidence-based treatment flowchart is proposed. CADM is a subtype of DM, related to higher incidences of interstitial lung disease, skin vasculopathy and malignancy. When ulcers or interstitial pneumonia are present, treatment should be early and aggressive. Active screening for neoplasms is recommended, particularly within the first 5 years.

Conclusion

The authors presented a case of seronegative CADM featuring skin vasculopathy, successfully treated with consecutive methylprednisolone pulses. Our literature review emphasized the importance of focused CADM management trials, highlighting the need for further research.

Association Between HLA Alleles and Autoantibodies in Dermatomyositis Defined by Sarcoplasmic Expression of Myxovirus Resistance Protein A

OBJECTIVE

The diagnosis in the studies analyzing HLA of dermatomyositis (DM) was based on a combined clinical category of polymyositis/DM. This retrospective study investigated the associations of HLA with 5 DM-specific autoantibodies in Japanese patients diagnosed by muscle pathology.

METHODS

We diagnosed Japanese patients with DM based on sarcoplasmic expression of myxovirus resistance protein A. These patients underwent investigation for 5 DM-specific autoantibodies and HLA genotyping.

RESULTS

Of 175 patients (83 males and 92 females; range 1-86 yrs; mean 46 yrs), 173 (98.9%) had 1 of the 5 autoantibodies. Seven alleles-A*02:07, B*46:01, DRB1*04:07, DRB1*07:01, DRB1*08:03, DQB1*06:01, and DPB1*02:02-were more frequently detected in the patients with DM than healthy controls, but these associations were not significant after multiple testing correction. Stratifying by DM-specific autoantibodies, we found the associations of 6 already known and 7 new alleles-B*48:01, B*52:01, C*12:02, DRB1*04:05, DRB1*15:02, DPB1*05:01, and DPB1*09:01-with subsets of DM. Moreover, significant associations of 5 alleles with antinucleosome remodeling deacetylase complex (Mi-2) remained after multiple testing correction. In particular, the DRB1*04:07 (odds ratio [OR 28.9]; corrected P = 2.7 × 10-6) and DQB1*06:01 (OR 4.0; corrected P = 1.6 × 10-4) alleles were significantly more prevalent in patients with anti-Mi-2 antibody than in controls.

CONCLUSION

This study demonstrates DM-specific autoantibodies defined immunogenetic subsets of DM.

Collagen Vascular Diseases: A Review of Cutaneous and Systemic Lupus Erythematosus, Dermatomyositis, and Distinguishing Features in Skin of Color

Collagen vascular diseases such as lupus erythematosus and dermatomyositis (DM) occur 2 to 3 times more often among patients with skin of color. In this article, the authors review DM and cutaneous lupus erythematosus, including acute cutaneous lupus erythematosus, subacute cutaneous lupus erythematosus, and discoid lupus erythematosus. They discuss the distinguishing features between these entities and highlight distinct presentations and management considerations in patients with skin of color to aid in prompt and correct diagnoses in this patient population.

Long-term follow-up of Janus-kinase inhibitor and novel active disease biomarker in juvenile dermatomyositis

OBJECTIVE

To evaluate the use of Janus kinase inhibitor (JAKi) in treating JDM and develop cytokine biomarkers of active disease.

METHODS

This study involved a retrospective cohort study that evaluated JAKi in 101 JDM patients as well as a cross-sectional study of cytokines in 128 JDM patients and 30 controls between November 2017 and December 2021 in the Affiliated Children's Hospital of Capital Institute of Pediatrics (China).

RESULTS

During the median follow-up period of 19 months, 65.5% of the patients had improved rashes, and CAT-BM scores decreased. Overall, 39.6% of JDM patients eliminated glucocorticoids. Muscle strength was improved in all patients who had abnormal muscle strength before JAKi use. Patients and parents provided positive subjective reviews of JAKi, and no serious adverse events were reported. Potential side effects of JAKi included abnormal leukopoenia (14/95) and cough (16/83), which affected over 10% of the JDM patients. In the cytokine analysis, 12/34 cytokines were significantly elevated in active JDM patients. Compared with active JDM patients with multiple phenotypes, active JDM patients with only rashes demonstrated lower cytokine levels. Anti-NXP2-positive active patients had lower cytokine levels compared with those without positive anti-NXP2 antibodies. Among all increased cytokines, IL-1RA changed most dramatically, reaching over 793 times the mean of normal values. We developed a panel composed of six cytokines to differentiate active or stable status in our cohort (area under the curve = 0.8486, P < 0.05).

CONCLUSION

The preliminary evidence suggested that JAKi is a relatively safe and effective alternative for JDM patients. Cytokine profiles could well reflect the inflammatory status of JDM patients.

Clinical Characteristics of Dermatomyositis with Interstitial Lung Disease: A Retrospective Case-Control Study

INTRODUCTION

Interstitial lung disease (ILD) is a common complication of dermatomyositis (DM) and one of the main risk factors for poor prognosis in DM patients. The aim of this study was to reveal the clinical characteristics of DM patients with ILD.

METHODS

Clinical data from the Second Affiliated Hospital of Soochow University were used to conduct a retrospective case-control study. Univariate and multivariate logistic regression analysis were performed to identify risk factors for ILD in DM.

RESULTS

A total of 78 DM patients were included in this study, including 38 DM patients with ILD and 40 DM patients without ILD. Compared with patients without ILD, patients with ILD were older (59.6 vs. 51.2 years, P = 0.004), and had higher rates of clinically amyopathic DM (CADM) (45 vs. 20%, P = 0.019), Gottron's papules (76 vs. 53%, P = 0.028), mechanic's hands (13 vs. 0%, P = 0.018), myocardial involvement (29 vs. 8%, P = 0.014), and higher positive rates of anti-SSA/Ro52 (74 vs. 20%, P < 0.001) and anti-melanoma differentiation-associated gene-5 (MDA5) (24 vs. 8%, P = 0.048) antibodies, while albumin (ALB) (34.5 vs. 38.0 g/l, P = 0.006), prognostic nutritional index (PNI) (40.3 vs. 44.7, P = 0.013), the rates of muscle weakness (45 vs. 73%, P = 0.013) and heliotrope rash (50 vs. 80%, P = 0.005) were lower. In addition, the five patients who died were all DM patients with ILD (13 vs. 0%, P = 0.018). Multivariate logistic regression showed that old age (odds ratio [OR] = 1.119, 95% confidence interval [CI] = 1.028-1.217, P = 0.009), Gottron's papules (OR = 8.302, 95% CI = 1.275-54.064, P = 0.027) and anti-SSA/Ro52 (OR = 24.320, 95% CI = 4.102-144.204, P < 0.001) were independent risk factors for ILD in DM.

CONCLUSIONS

DM patients with ILD usually present with older age, higher rates of CADM, Gottron's papules, mechanic's hands, myocardial involvement, higher positive rates of anti-MDA5 and anti-SSA/Ro52 antibodies, lower ALB, PNI, and lower rates of muscle weakness and heliotrope rash. Old age, Gottron's papules, and anti-SSA/Ro52 were independent risk factors for ILD in DM.

Evolution of Seronegative Inflammatory Myositis to Dermatomyositis With Characteristic Cutaneous Features: A Case Report

Dermatomyositis (DM) is a rare inflammatory myopathy with an incidence of 9.63 per 1 000 000 people and typically presents with skin rash and muscle weakness. We report a case of DM that presented with proximal muscle weakness, normal creatine phosphokinase (CPK), negative myositis antibody panel, and non-specific histopathological findings on muscle biopsy, without initial skin involvement. A 67-year-old male presented with subacute bilateral proximal lower-extremity weakness and weight loss of 20 pounds over 3 months. Laboratory investigation was significant for elevated erythrocyte sedimentation rate, C-reactive protein, CPK, and aldolase, with negative myositis-specific antibodies. Femur magnetic resonance imaging revealed subcutaneous, fascial, and muscle edema throughout quadriceps and gluteal muscles. Muscle biopsy showed myofiber atrophy with perivascular and endomysial T-lymphocytes and histiocytes, as well as scattered necrotic myofibers. He was diagnosed with inflammatory myositis and started on prednisone and monthly IVIG infusions. At 2-month follow-up, he reported new rashes on the extensor surfaces of the hands consistent with Gottron's papules, mechanic's hands, and livedo reticularis of feet and arms. Cases of DM that present with myopathy and later develop skin changes are rare. Our patient had several months of progressive proximal muscle weakness, and skin changes occurred after he was started on treatment. Laboratory findings include elevated CPK, aldolase, and myositis-specific auto-antibodies. Muscle biopsy helps in diagnosis; however, findings may be nonspecific-as was the case in our patient. Corticosteroids are first-line treatment. Long-term follow-up studies are necessary to better understand the incidence of late-onset development of typical skin findings.

Cutaneous Involvement in Systemic Lupus Erythematosus: A Review for the Rheumatologist

The majority of patients with systemic lupus erythematosus (SLE) have cutaneous manifestations at some point in their disease course. The skin findings in SLE are classified as SLE-specific or SLE-nonspecific based on histopathologic findings. SLE-specific skin diseases include chronic cutaneous lupus erythematosus (CLE), subacute CLE, and acute CLE. There are subsets of skin lesions within each group and the likelihood of associated SLE varies among them. SLE-nonspecific lesions are more common in patients with SLE and tend to coincide with active systemic disease. SLE-nonspecific lesions may be seen as a feature of another disease process, including other connective tissue diseases. It is important for the rheumatologist to be familiar with the spectrum of cutaneous diseases in SLE to help prognosticate the likelihood of systemic disease and to ensure patients receive timely dermatologic care with the goal of controlling disease activity to prevent damage.

Management of dermatomyositis patients amidst the COVID-19 pandemic: Two case reports

RATIONALE

In December 2019, a new epidemic of coronavirus disease 2019 (COVID-19) appeared in Wuhan, Hubei Province, and spread rapidly to other parts of China and worldwide. Although established methods exist for the diagnosis and treatment of COVID-19 infection, the management of dermatomyositis (DM) patients with COVID-19 is unknown.

PATIENT CONCERNS

In this article, we describe case reports of 2 patients with DM. The first case was a 67-year-old patient with DM and infected with COVID-19 who was admitted to Leishenshan Hospital for a 1-month history of fever, cough, and expectoration. The second case was a 51-year-old male patient who was admitted to Leishenshan Hospital due to fever with cough, expectoration and shortness of breath for 1 month.

DIAGNOSES

The first patient was diagnosed with COVID-19 secondary to DM based on repeated SARS-CoV-2 real-time reverse-transcriptase polymerase-chain-reaction (RT-PCR) test, detailed medical history and chest computed tomography; The second patient was diagnosed with interstitial lung disease associated with anti-MDA5 DM based on the results of antirheumatic and anti-inflammatory therapy and the above 3 methods.

INTERVENTIONS AND OUTCOMES

The first patient received supportive and empirical treatment, including antiviral treatment, anti-inflammatory treatment, oxygen therapy and prophylactic anticoagulation therapy. The symptoms and laboratory results got improved after the treatments. He was discharged with thrice negative PCR tests for the SARS-CoV-2 virus. The second patient received a comprehensive treatment, including glucocorticoid and plasma exchange; his symptoms were relieved and improved.

LESSONS

These cases suggest that repeated new pathogenic test results for the coronavirus and a detailed diagnosis of the medical history are important means to distinguish these diseases. Increased attention to the individual characteristics of different cases may allow for more effective diagnosis and treatment.

Clinical characteristics of idiopathic interstitial pneumonias with anti-Ro52/tripartite motif-containing 21 antibodies

Antibodies to Ro52/tripartite motif-containing 21 (TRIM21), referred to as anti-Ro52, are found in patients diagnosed with diverse systemic autoimmune rheumatic disease and associated with interstitial lung diseases. However, little is known about the clinical characteristics of anti-Ro52 in patients with idiopathic interstitial pneumonias (IIPs). We aimed to analyze the prevalence, co-existent autoantibodies, and clinical characteristics of anti-Ro52 in patients with IIP. The study enrolled 288 patients diagnosed with IIP. Clinical, laboratory and radiographic findings of IIP patients were compared between anti-Ro52 positives and negatives. Anti-Ro52 (20/288; 6.9%), anti-ARS (18/288; 6.3%), and anti-Ro60/SS-A (16/288; 5.6%) were the most common autoantibodies detected in IIP patients. Among 20 IIP patients who had anti-Ro52, anti-ARS was present in 8 (40%) patients. The criteria for interstitial pneumonia with autoimmune features (IPAF) were significantly better fulfilled by patients with anti-Ro52 than those without (P = 0.001). Meeting serological domain (P < 0.001) and Raynaud’s phenomenon (P = 0.009) were significantly more common in the anti-Ro52-positive patients. Anti-Ro52-positive IIP patients have clinical features consistent with IPAF. Anti-Ro52 may have an important role in detecting the autoimmune phenotype in IIP patients.

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.

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.

Identification of Vital Hub Genes and Potential Molecular Pathways of Dermatomyositis by Bioinformatics Analysis

Dermatomyositis is an autoimmune disease characterized by severe symmetrical muscle dysfunction and pain. This study was aimed at discovering vital hub genes and potential molecular pathways of DM through bioinformatics analysis, which contributes to identifying potential diagnostic or therapeutic biomarkers and targets. In this study, a total of 915 DEGs in DM samples including 167 upregulated genes and 748 downregulated genes were screened out by the limma package based on the GSE142807 dataset from the Gene Expression Omnibus (GEO) database. Furthermore, the results of Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that these downregulated genes were highly associated with the immune-related biological processes and pathways. Therefore, 41 genes closely related to DM were extracted for further study based on the subcluster analysis through the Molecular Complex Detection (MCODE) software plugin in Cytoscape. Ultimately, 10 hub genes (including ISG15, DDX58, IFIT3, CXCL10, and STAT1) were identified as the potential candidate biomarkers and targets. Besides, we found that the identified hub genes directly or indirectly communicated with each other via molecular signaling pathways on the protein and transcription level. In general, under the guidance of bioinformatics analysis, 10 vital hub genes and molecular mechanisms in DM were identified and the expression of proinflammatory factors and interferon family proteins and genes showed high association with DM, which might help provide a theoretical foundation for the development of point-to-point targeted therapy in the future treatment of DM.

Elevated carcinoembryonic antigen predicts rapidly progressive interstitial lung disease in clinically amyopathic dermatomyositis

OBJECTIVES

The present study aimed to determine the correlation between serum carcinoembryonic antigen (CEA) level and the severity of interstitial lung disease (ILD) in clinically amyopathic DM (CADM) patients.

METHODS

We performed a retrospective study including 41 Chinese CADM patients without malignancy. Serum CEA levels, clinical and laboratory findings were collected. Association tests between CEA levels and disease activity parameters were performed.

RESULTS

Among the 41 patients, 16 (39.0%) developed rapidly progressive (RP)-ILD; of them, 14 (87.5%) had elevated serum CEA levels. Multivariate logistic regression analysis indicated that an elevated serum CEA level was an independent risk factor for RP-ILD. The incidence of elevated CEA level was significantly higher in patients with RP-ILD than in those without RP-ILD (87.5 vs 16.0%, P < 0.001). Furthermore, CEA levels were higher in patients with CADM with RP-ILD [26.87 (6.71) μg/l] than in those without RP-ILD [3.23 (0.64) μg/l] (P < 0.001). CEA levels in CADM patients were associated with the ferritin, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase levels, and CT scores of the lungs. Also, elevated CEA levels are related to the organizing pneumonia pattern and lower lung zone consolidation in high-resolution CT. Moreover, the cumulative survival rate was significantly lower (68.4 vs 31.6%, P < 0.001) in the group with a CEA level >8.75 μg/l than that in the group with a CEA level <8.75 μg/l.

CONCLUSIONS

An elevated serum CEA level is common in patients with CADM, and a higher serum CEA level is a powerful indicator of RP-ILD and poor prognosis in those patients.

Clinically amyopathic dermatomyositis presenting with isolated facial edema complicated by acute respiratory failure: a case report

BACKGROUND

In clinically amyopathic dermatomyositis, the hallmark cutaneous manifestations are the key to diagnosis. We report a case of clinically amyopathic dermatomyositis which presented with facial edema as the sole cutaneous manifestation and was later complicated by acute respiratory failure leading to death.

CASE PRESENTATION

A 58-year-old woman presented with edema of the face that had developed approximately one year ago. There was no weakness in the extremities, and the serum creatine kinase level was within normal range. On MRI, there was diffuse edematous change in the bilateral masticator and extra-ocular muscles, accompanied by subcutaneous fat infiltration in the face. A shared decision was made to defer muscle biopsy in the facial muscles. The facial swelling almost resolved with medium-dose glucocorticoid therapy but relapsed in days at glucocorticoid doses lower than 15 mg/day. Combination therapy with either azathioprine, mycophenolate, or methotrexate was not successful in maintaining clinical remission, and the swelling became more severe after relapses. A US-guided core-needle biopsy was subsequently performed in the right masseter muscle. On pathologic examination, there was a patchy CD4 + T cell-dominant lymphoplasmacytic infiltration in the stroma, necrosis of the myofibrils and prominent perifascicular atrophy. Based on those findings, a diagnosis of clinically amyopathic dermatomyositis was made. Therapy with gamma-globulin was not effective in maintaining remission. In the sixth week after starting rituximab, she presented to emergency room with altered mental state from acute respiratory failure. Despite treatment with antibiotics, glucocorticoid pulse, cyclosporin, and polymyxin B-immobilized fiber column direct hemoperfusion, she died three weeks later from persistent hypoxemic respiratory failure.

CONCLUSIONS

This case showed the full spectrum and severity of internal organ involvement of dermatomyositis, although the patient presented exclusively with subcutaneous edema limited to the head. The prognosis may be more closely associated with a specific auto-antibody profile than the benign-looking initial clinical manifestation. Close follow-up of lung involvement with prophylactic treatment for Pneumocystis pneumonia and prompt implementation of emerging therapeutic regimens may improve the outcome.

Risk factors of interstitial lung diseases in clinically amyopathic dermatomyositis

Background

Clinically amyopathic dermatomyositis (CADM) is a unique sub-type of idiopathic inflammatory myopathies with a high prevalence of interstitial lung disease (ILD). Poor prognosis of the patients was strongly associated with rapid progressive ILD. The aim of this study was to identify risk factors for prediction of different types of ILD in CADM.

Methods

In this study, data of 108 inpatients with CADM were collected, including 87 with ILD. The baseline clinical data and laboratory parameters, including myositis-specific and associated antibodies and tumor-associated antigens were analyzed to identify risk factors for acute or subacute interstitial pneumonitis (A/SIP) and chronic interstitial pneumonitis (CIP).

Results

In 87 patients with CADM-ILD, 39 (36.1%) were A/SIP, and 48 (44.4%) were CIP. There were 22 (20.4%) patients with asymptomatic ILD who were detected by routine high resolution computed tomography. Cytokeratin-19 fragment (CYFRA21-1) was significantly higher in CADM-ILD than that in CADM patients without ILD; carcinoembryonic antigen and neuron-specific enolase were significantly elevated in A/SIP than that in CIP. Patients with A/SIP had a higher positive rate of anti-melanoma differentiation-associated gene 5 (MDA5), while patients with CIP had a higher positive rate of anti PL-12 and anti-Ro-52. Logistic regression analysis indicated that elevation of CYFRA21-1 was a risk factor for ILD, higher titer of anti-MDA5 indicated increased likelihood for A/SIP, and higher titer of anti-Ro-52 was also clearly associated with CIP.

Conclusions

This study indicated that the prevalence of ILD was high in CADM. Asymptomatic ILD has been previously underestimated. Anti-MDA5 was a risk factor for the presence of A/SIP, and CYFRA21-1 was a risk factor for ILD.

The relationship between JAK2(V617F) mutation and dermatomyositis-a case report and literature review

The JAK family (JAK1, JAK2, JAK3, and TYK2) have recently emerged as a potential therapeutic management in controlling severe and refractory dermatomyositis. Meanwhile, the progress in the discovery of JAK blockers is significant, with an increasing number of selective JAK inhibitors reported and some are in or prepare for clinical trials. However, the importance of each JAK in dermatomyositis is unclear, which is critical for a comprehensive understanding of dermatomyositis and significant for forming mechanism-based strategy. Here, we presented a case with clinically amyopathic dermatomyositis and essential thrombocytosis with a somatic constitutive active mutation of JAK2(V617F). The coexistence of these two uncommon diseases attracted us to investigate their underlying relationship. To this end, we characterized the clinical course and laboratory findings of this patient. Particularly, we correlated JAK2(V617F) mutation burden in affected peripheral blood subset with clinical activity score of dermatomyositis. Based on our observation, we concluded that these two diseases are independent disorders, and JAK2(V617F) mutation burden is irrelevant to the severity of dermatomyositis. Finally, we reviewed the literature and summarized them with a thorough discussion.

Nailfold Videocapillaroscopy is a Useful Tool to Recognize Definite Forms of Systemic Sclerosis and Idiopathic Inflammatory Myositis in Interstitial Lung Disease Patients

Nailfold videocapillaroscopy (NVC) is an easy tool used for the assessment of patients with Raynaud's phenomenon (RP) as possibly associated with systemic sclerosis (SSc). Recent insights have also highlighted its role in the diagnostic assessment of idiopathic inflammatory myopathies (IIMs). The aim of this study is to describe the diagnostic role of NVC in a series of 361 consecutive patients with interstitial lung disease (ILD). All the patients were assessed by clinical pulmonary and rheumatic examinations, blood exams, high-resolution computed tomography and NVC. NVC was considered positive only in the presence of avascular areas or giant capillaries, but also, the presence of bushy capillaries (BCs) was recorded. NVC was positive in 17.7% of ILD patients and in 78.1% of ILD patients associated with a diagnosis of connective tissue disease (CTD). In 25% of SSc-ILD patients, NVC proved necessary for a correct diagnosis. The presence of BCs and/or NVC positivity in ILD patients with normal levels of creatine phosphokinase is associated with amyopathic IIM, regardless the presence of RP. In conclusion, NVC is useful for the diagnostic assessment of incomplete forms of CTD and in amyopathic IIMs. NVC should be considered in the diagnostic assessment of ILD patients regardless of the presence of RP.

Dermatomyositis presenting as heart failure revealed a concealed cervical malignancy: an infrequent clinical nexus

Dermatomyositis (DM) belongs to the spectrum of inflammatory myopathies which are a heterogeneous group of acquired disorders in which dysregulated immune system is thought to play a major pathologic role. Patients with DM generally present with characteristic skin manifestations with or without muscle weakness and pain. Although subclinical myocardial involvement in DM is well reported in literature, heart failure (HF) as its principal manifestation is extremely rare. Recognition of DM, a known paraneoplastic syndrome, should prompt clinicians to search for underlying malignancy. While gynaecological malignancies are common in association with DM, cervical cancer has rarely been heard of as an aetiology of paraneoplastic DM. We are reporting a case of DM in a postmenopausal woman presenting with advanced decompensated congestive HF with hidden squamous cell carcinoma of cervix.

Noninvasive positive pressure ventilator deteriorates the outcome of pneumomediastinum in anti-MDA5 antibody-positive clinically amyopathic dermatomyositis

BACKGROUND

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab)-positive clinically amyopathic dermatomyositis (CADM) with pneumomediastinum (PNM) is a life-threatening condition. We aim to determine the prognostic factors affecting survival of patients with anti-MDA5 Ab-positive CADM complicated with PNM.

METHODS

We retrospectively established a cohort of patients with anti-MDA5 Ab-positive CADM complicated with PNM from April 2013 to July 2019. Demographic data and clinical characteristics from medical records were analyzed and variables were compared between survivors and nonsurvivors. We performed univariate and multivariate survival analyses by Cox regression. Survival curves were depicted by the Kaplan-Meier method.

RESULTS

Among 133 patients with anti-MDA5 Ab-positive CADM, 20 were diagnosed with PNM. The cumulative estimated Kaplan-Meier survival rate was 85% at 1 week, 55% at 1 month, and 40% at 1 year. Univariate analysis indicated several factors associated with survival. Worse liver function (AST, p = 0.043; LDH, p = 0.002; TBIL, p = 0.038), higher CRP level (p = 0.044), higher HRCT score (p = 0.022), and using noninvasive positive pressure ventilation (NPPV) (p < 0.01) were associated with poor prognosis. In a multivariate Cox regression model, AST level and using NPPV were indicated to be independent predictors of poor prognosis.

CONCLUSION

In this research, we found that the incidence rate of PNM in anti-MDA5 Ab-positive CADM was 15.5%, obviously higher than in classical DM. The application of noninvasive positive pressure ventilator (NPPV) and higher AST level were independent risk factors for survival.Key Points• Anti-MDA5 Ab-positive CADM complicated with PNM is a life-threatening condition with an incidence rate of 15.5%.• The application of NPPV and worse liver function were independent risk factors for survival of anti-MDA5 Ab-positive CADM patients complicated with PNM.

Myositis Specific Autoantibodies: A Clinical Perspective

Dermatomyositis (DM) is an idiopathic inflammatory condition characterized by myositis and variable skin manifestation. The existence of myositis specific autoantibodies usually manifests with varying degrees of skin or muscle inflammations. The condition has a well-established association with most clinical phenotypes, and these autoantibodies are useful in informing the diagnosis, management and prognosis of the disease. DM-specific autoantibodies include anti-MDA5, anti-NXP2, anti-SAE, anti-Mi-2, anti-ARS, anti-TIF1-gamma. Anti-Mi-2 antibodies are widely associated with DM cases that exhibit mainly cutaneous symptoms, such as cuticular overgrowths, Gottron's papules while being less susceptible to complications like interstitial lung disease or malignancy. The most distinct clinical features of patients with anti-SAE antibodies are their high prevalence of dysphagia and cutaneous manifestations that antecede the development of myopathies. In addition, DM patients with positive anti-PL-7 antibodies tend to have milder myositis characterized by low levels of creatine kinase as compared to patients with positive anti-Jo-1 antibodies. The anti-NXP2 antibodies are associated with transcriptional regulation and production of various proteins targeted by other DM antibodies, while anti- TIF1-γ. facilitates the transcription of deoxyribonucleic acids and regulates the growth and subsequent differentiation of body cells by controlling the signaling of TGF-β. The present review targets DM specific autoantibodies, considering their association, significance, and clinical presentation.

The validity and utility of the Cutaneous Disease Area and Severity Index (CDASI) as a clinical outcome instrument in dermatomyositis: A comprehensive review

INTRODUCTION

Validated outcome measures are paramount in the assessment of disease progression and evaluation of new therapeutics in clinical trials. Dermatomyositis (DM) is an autoimmune disease that is frequently refractory to current therapies and warrants the development of new treatments. The Cutaneous Disease Area and Severity Index (CDASI) was developed in 2008 in response to a need for a reliable, validated measure of skin disease activity and damage for use in clinical trials and longitudinal monitoring of disease progression.

METHODS

The literature was searched for all studies validating and utilizing the CDASI between 2008 and October 2018 using searches in PubMed. Studies pertaining to validation of the CDASI, correlation with quality of life, use in the evaluation of current therapies and ongoing trials, as well as relationships to biomarkers were included in this review.

RESULTS

The CDASI was found to have intra- and inter-rater reliability, validity, reproducibility, sensitivity to clinical changes, and ease of use. It has been shown to correlate with quality of life as measured by the Skindex-29 outcome measure. The CDASI activity score has additionally been shown to correlate significantly with IFN-β, a key cytokine in DM pathogenesis.

CONCLUSION

The CDASI is a validated measure of dermatomyositis disease and has been shown to be an effective outcome instrument in clinical trials.

Efficiency of Therapeutic Plasma-Exchange in Acute Interstitial Lung Disease, Associated With Polymyositis/Dermatomyositis Resistant to Glucocorticoids and Immunosuppressive Drugs: A Retrospective Study

Interstitial lung disease (ILD) is a life-threating complication, commonly associated with polymyositis (PM), and dermatomyositis (DM). A subset of acute ILD associated with PM/DM patients are refractory to conventional treatment, and leads to a high rate of mortality. The efficacy of therapeutic plasma-exchange (TPE) as a PM/DM treatment to improve muscle involvement is controversial due to a lack of evidence. However, in recent reports, TPE has been effective in improving lung involvement. To evaluate the efficacy of this therapy, we retrospectively studied TPE treatment outcomes for in 18 acute PM/DM-ILD patients who were resistant to conventional therapies. Five patients were diagnosed with DM (27.8%), 11 with CADM (61.1%), and two with PM (11.1%). Among 18 patients, 11 (61.1%) achieved satisfactory improvement after four or more rounds of TPE, whereas seven died due to respiratory failure. We also analyzed risk factors to predict unresponsiveness to TPE in these patients. Notably, the prevalence of subcutaneous/mediastinal emphysema was significantly higher in the non-responsive group (6/7, 85.7%) than in the responsive group (2/11, 18.2%; P = 0.013); moreover, patients with this complication were mainly in the CADM subgroup (6/8, 75%). Subcutaneous/mediastinal emphysema and increased serum ferritin levels were shown to be poor prognostic factors, predictive of unresponsiveness to TPE, in PM/DM patients. No autoantibodies were found to be associated with TPE outcome, although we only investigated anti-Jo-1 and anti-Ro antibodies; the clinical significance of other myositis-specific autoantibodies, especially anti-melanoma differentiation-associated gene 5 (MDA5) antibody, is not known. Our results indicate that TPE might be an alternative treatment for acute PM/DM-ILD patients resistant to conventional therapies, except for those with subcutaneous/mediastinal emphysema and high serum ferritin levels.

Polymyositis and dermatomyositis - challenges in diagnosis and management

Polymyositis (PM) and dermatomyositis (DM) are different disease subtypes of idiopathic inflammatory myopathies (IIMs). The main clinical features of PM and DM include progressive symmetric, predominantly proximal muscle weakness. Laboratory findings include elevated creatine kinase (CK), autoantibodies in serum, and inflammatory infiltrates in muscle biopsy. Dermatomyositis can also involve a characteristic skin rash. Both polymyositis and dermatomyositis can present with extramuscular involvement. The causative factor is agnogenic activation of immune system, leading to immunologic attacks on muscle fibers and endomysial capillaries. The treatment of choice is immunosuppression. PM and DM can be distinguished from other IIMs and myopathies by thorough history, physical examinations and laboratory evaluation and adherence to specific and up-to-date diagnosis criteria and classification standards. Treatment is based on correct diagnosis of these conditions.

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Challenges of diagnosis and management influences the clinical research and practice of Polymyositis and dermatomyositis.

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Diagnostic criteria have been updated and novel therapies have been developed in PM/DM.

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Pathogenesis investigation and diagnosis precision improvement may help to guide future treatment strategies.

Autoantibodies in myositis

The discovery of novel autoantigen systems related to idiopathic inflammatory myopathies (collectively referred to as myositis) in adults and children has had major implications for the diagnosis and management of this group of diseases across a wide range of medical specialties. Traditionally, autoantibodies found in patients with myositis are described as being myositis-specific autoantibodies (MSAs) or myositis-associated autoantibodies (MAAs), depending on their prevalence in other, related conditions. However, certain MSAs are more closely associated with extramuscular manifestations, such as skin and lung disease, than with myositis itself. It is very rare for more than one MSA to coexist in the same individual, underpinning the potential to use MSAs to precisely define genetic and disease endotypes. Each MSA is associated with a distinctive pattern of disease or phenotype, which has implications for diagnosis and a more personalized approach to therapy. Knowledge of the function and localization of the autoantigenic targets for MSAs has provided key insights into the potential immunopathogenic mechanisms of myositis. In particular, evidence suggests that the alteration of expression of a myositis-related autoantigen by certain environmental influences or oncogenesis could be a pivotal event linking autoantibody generation to the development of disease.

Serum KL-6 level is a prognostic marker in patients with anti-MDA5 antibody-positive dermatomyositis associated with interstitial lung disease

Objective

This study aimed to investigate the clinical significance of Krebs von den Lungen‐6 (KL‐6) serum levels in patients with anti‐MDA5 antibody‐positive dermatomyositis (anti‐MDA5⁺ DM) having interstitial lung disease (ILD), especially in the amyopathic DM phenotype.

Methods

The serum KL‐6 level was measured using a chemiluminescence enzyme immunoassay (CLEIA) in patients with anti‐MDA5⁺ DM, including clinically amyopathic dermatomyositis (CADM)‐ILD and classic DM‐ILD, and healthy donors. The baseline and post‐treatment serum KL‐6 levels were determined in 39 patients with CADM‐ILD who experienced remission or acute exacerbation. The association between laboratory findings, high‐resolution computed tomography (HRCT) scores, pulmonary function tests (PFTs), and the predictive value of baseline KL‐6 level for death was analyzed.

Results

The serum KL‐6 levels were significantly higher in patients with CADM‐ILD (1339 ± 1329 U/mL) compared with DM‐ILD (642.3 ± 498.4 U/mL) and healthy donors (162.4 ± 54.01 U/mL). The KL‐6 levels correlated positively with chest HRCT scores, serum lactate dehydrogenase, serum ferritin levels, and PFTs, but not with erythrocyte sedimentation rate. During follow‐up, the post‐treatment serum KL‐6 levels significantly reduced in the remission/stable group, but increased in the acute exacerbation group. Higher levels of ferritin and KL‐6 and HRCT scores were independently associated with poor prognosis. The 1‐year survival rate was significantly lower in patients with high KL‐6 level than in those with low KL‐6 level.

Conclusion

The serum KL‐6 levels may be a useful marker for predicting and monitoring ILD in Chinese patients with anti‐MDA5⁺ DM, especially amyopathic DM phenotype.

Blood purification in two patients with clinically amyopathic dermatomyositis associated with interstitial lung disease with anti-melanoma differentiation-associated gene-5 antibody (MDA-5)

Patients of clinically amyopathic dermatomyositis associated with rapidly progressive interstitial pneumonia (CADM-RFIP) with positive anti-MDA5 antibody usually presents rapid deterioration and traditional therapy such as cyclophosphamide combined with high-dose prednisone pulse therapy shows no clear benefit at whiles. However, blood purification combined with traditional therapy works according to the literature. We herein report two CADM-RFIP patients administered with DNA immunoadsorption combined with traditional therapy and then reviewed the literature of blood purification in CADM-RFIP patients at home and abroad to date. We emphasize blood purification such as DNA immunoadsorption could apply in the early stage of CADM-RFIP, which can decrease inflammation and allow us more time to control the condition better.

Features distinguishing clinically amyopathic juvenile dermatomyositis from juvenile dermatomyositis

Objective

We examined features of clinically amyopathic JDM (CAJDM), in which patients have characteristic rashes with little to no evidence of muscle involvement, to determine whether this is a distinct phenotype from JDM.

Methods

Demographic, clinical, laboratory and treatment data from 12 (9 hypomyopathic, 3 amyopathic) patients meeting modified Sontheimer criteria for CAJDM and from 60 matched JDM patients meeting Bohan and Peter criteria were examined. Differences were evaluated by Fisher's exact and Mann-Whitney tests, random forests and logistic regression analysis.

Results

Nine (75%) CAJDM patients had anti-p155/140 (transcriptional intermediary factor 1), one (8.3%) anti-melanoma differentiation-associated gene 5 autoantibodies and two (16.7%) were myositis autoantibody negative. CAJDM patients were younger at diagnosis and frequently had mild disease at onset. CAJDM patients had less frequent myalgias, arthritis, contractures, calcinosis, dysphagia, abdominal pain and fatigue. The muscle, skeletal and overall clinical scores were lower in CAJDM. Serum muscle enzymes were less frequently increased in CAJDM, and peak values were lower. CAJDM patients received fewer medications compared with JDM patients. Only 50% of CAJDM patients received oral prednisone, but the maximum dose and treatment duration did not differ from JDM. At a median follow-up of 2.9 years, CAJDM patients had no documented functional disability, and none developed weakness, calcinosis, interstitial lung disease or lipodystrophy. Multivariable modelling revealed a lower skeletal score and less frequent myalgias as the most important factors in distinguishing CAJDM from JDM.

Conclusion

CAJDM may be distinguished from JDM, in that they often have p155/140 (transcriptional intermediary factor 1) autoantibodies, have fewer systemic manifestations and receive less therapy.

Combined usage of extracorporeal membrane oxygenation and double filtration plasmapheresis in amyopathic dermatomyositis patient with severe interstitial lung disease: A case report

RATIONALE

We report a man with amyopathic dermatomyositis (ADM) complicated by severe interstitial lung disease (ILD) received extracorporeal membrane oxygenation (ECMO) in combination with double filtration plasmapheresis (DFPP). This is the first report of the utility of ECMO in combination with DFPP in ADM related ILD in adults.

PATIENT CONCERNS

A 48-year-old man who was previously healthy had a 2-month history of cough and shortness of breath, which aggravated in 5 days.

DIAGNOSES

Amyopathic dermatomyositis and complicated by severe interstitial lung disease.

INTERVENTIONS

ECMO was giving when the patient suffered acute respiratory failure. Though corticosteroids was giving, primary disease was still developing with relapses of spontaneous pneumomediastinum and pneumothorax. Then, DFPP treatment was initiated.

OUTCOME

After the treatments above, the patient's clinical condition improved with the reduction of bilateral interstitial infiltrates and improvement of lung compliance. Unfortunately, he discontinued the treatment because of the financial problem.

LESSONS

When get a rapid progressive interstitial lung disease for no apparent reason, amyopathic dermatomyositis should be considered, especially with suspected skin lesions. ECMO, in combination with DFPP, should be considered as a supportive therapy and initiated early in patients in acute respiratory failure secondary to ADM-ILD. Prompt initiation of DFPP in dermatomyositis patients with ILD might help reduce the occurrence of spontaneous pneumomediastinum or pneumothorax.

The prevalence and clinical significance of anti-PUF60 antibodies in patients with idiopathic inflammatory myopathy

Autoantibodies against poly-U-binding factor 60 kDa protein (PUF60) have been reported in Caucasian dermatomyositis (DM) patients. However, their clinical significance in idiopathic inflammatory myopathy (IIM) remains to be fully clarified. Our objective was to analyze the prevalence and clinical significance of anti-PUF60 antibodies in a large cohort of Chinese IIM patients. In our study, 388 IIM patients, 301 disease controls, and 167 healthy controls (HCs) were involved. An enzyme-linked immunosorbent assay (ELISA) was developed to detect serum anti-PUF60 levels and was validated using immunoblotting methods. Unpaired Mann-Whitney U test and Spearman correlation analysis were used when appropriate. Anti-PUF60 antibodies were observed in IIM patients at a frequency of 10.6% (41/388). Subgrouping analysis revealed that the prevalence of anti-PUF60 antibodies was 10% in DM, 5.5% in polymyositis (PM), 10% in immune-mediated necrotizing myositis (IMNM), and 26.5% in myositis-overlap syndrome. Anti-PUF60 antibodies were also observed in systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and Sjögren's syndrome (SS) patients at a positive rate of 17.3, 14.5, and 10.1% respectively. Intriguingly, anti-PUF60 antibodies were frequently observed in clinically amyopathic dermatomyositis (CADM) patients and DM patients without currently known myositis autoantibodies. Furthermore, DM patients with anti-PUF60 antibodies had higher prevalence of skin ulcerations. Moreover, longitudinal investigation in eight DM patients with anti-PUF60 antibodies revealed that the antibodies levels decreased with disease remission. Anti-PUF60 antibodies were nonspecific for myositis, since they could be detected in other rheumatic diseases. Further investigation of anti-PUF60 antibodies may reveal shared pathogenic pathways in systemic autoimmune disorders.

Diagnosis and Management of Immune-Mediated Myopathies

Immune-mediated myopathies (IMMs) are a heterogeneous group of acquired muscle disorders characterized by muscle weakness, elevated creatine kinase levels, and myopathic electromyographic findings. Most IMMs feature the presence of inflammatory infiltrates in muscle. However, the inflammatory exudate may be absent. Indeed, necrotizing autoimmune myopathy (NAM), also called immune-mediated necrotizing myopathy, is characterized by a necrotizing pathologic process with no or minimal inflammation in muscle. The recent discovery of antibodies associated with specific subtypes of autoimmune myopathies has played a major role in characterizing these diseases. Although diagnostic criteria and classification of IMMs currently are under revision, on the basis of the clinical and muscle histopathologic findings, IMMs can be differentiated as NAM, inclusion body myositis (IBM), dermatomyositis, polymyositis, and nonspecific myositis. Because of recent developments in the field of NAM and IBM and the controversies around polymyositis, this review will focus on NAM, IBM, and dermatomyositis.

Childhood Arthritis and Rheumatology Research Alliance consensus clinical treatment plans for juvenile dermatomyositis with skin predominant disease

BACKGROUND

Juvenile dermatomyositis (JDM) is the most common form of the idiopathic inflammatory myopathies in children. A subset of children have the rash of JDM without significant weakness, and the optimal treatments for these children are unknown. The goal of this study was to describe the development of consensus clinical treatment plans (CTPs) for children with JDM who have active skin rashes, without significant muscle involvement, referred to as skin predominant JDM in this manuscript.

METHODS

The Children's Arthritis and Rheumatology Research Alliance (CARRA) is a North American consortium of pediatric rheumatology health care providers. CARRA members collaborated to determine consensus on typical treatments for JDM patients with skin findings without significant weakness, to develop CTPs for this subgroup of patients. We used a combination of Delphi surveys and nominal group consensus meetings to develop these CTPs.

RESULTS

Consensus was reached on patient characteristics and outcome assessment, and CTPs were developed and finalized for patients with skin predominant JDM. Treatment option A included hydroxychloroquine alone, Treatment option B included hydroxychloroquine and methotrexate, and Treatment option C included hydroxychloroquine, methotrexate and corticosteroids.

CONCLUSIONS

Three CTPs were developed for use in children with skin predominant JDM, which reflect typical treatment approaches. These are not considered to be specific recommendations or standard of care. Using the CARRA network and prospective data collection, we will be able to apply statistical methods in the future to allow comparisons of JDM patients following these consensus treatment plans.

Amyopathic Dermatomyositis: A Concise Review of Clinical Manifestations and Associated Malignancies

Amyopathic dermatomyositis is a rare, idiopathic, connective tissue disease that presents with dermatologic lesions of classic dermatomyositis but lacks the myopathy of this disease. Cutaneous manifestations may include Gottron's sign, heliotrope rash, and characteristic patterns of poikiloderma. There is a substantial risk for developing interstitial lung disease or malignancy in patients with amyopathic dermatomyositis. A literature review of amyopathic dermatomyositis was performed using the PubMed medical database. The key features of amyopathic dermatomyositis, including autoantibodies, clinical presentation and dermatologic manifestations, epidemiology, history, associated malignancies, management, and pathogenesis, are summarized in this review. Cancer (solid tumor) (73/79, 89 %) and hematologic malignancies (9/79, 11 %) were reported in 79 patients, with three patients having more than one malignancy. In addition, there were six patients with amyopathic dermatomyositis who had tumor of unknown primary, and eight patients with cancer-associated amyopathic dermatomyositis for whom no additional details were provided. From the group of 73 tumors for whom primary origin and sex were available, malignancy of the genitourinary organs (24/73, 33 %), aerorespiratory organs (15/73, 21 %), and breast (14/73, 19 %) were the most commonly observed solid organ tumors. Tumors of the genitourinary organs (15/48, 31 %) and breast (14/48, 29 %) were the most frequent neoplasms in women, accounting for 29 of 48 (60 %) cancers, with the most common sites being breast (14/48, 29 %), ovary (8/48, 17 %), and cervix or uterus (5/48, 10 %). In men, tumors of the aerorespiratory (9/25, 36 %) and genitourinary (9/25, 36 %) tracts were the most common neoplasms, accounting for 72 % (18/25) of cancers; the most common sites of primary malignancy were nasopharyngeal (6/25, 24 %), bladder (4/25, 16 %), and either colorectal, lung or prostate cancer (three cancers each, 12 %). In summary, the search for an undiagnosed associated malignancy in patients with amyopathic dermatomyositis should focus towards the organs most frequently affected. Similar to classic dermatomyositis, ovarian and nasopharyngeal cancers are also common in amyopathic dermatomyositis. However, in contrast to lung cancer, which is the most frequent malignancy associated with classic dermatomyositis, breast cancer was the most common type of malignancy reported in patients with amyopathic dermatomyosotis.

Diagnosis and classification of idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of diseases, collectively termed myositis, sharing symptoms of muscle weakness, fatigue and inflammation. Other organs are frequently involved, supporting the notion that these are systemic inflammatory diseases. The IIMs can be subgrouped into dermatomyositis, polymyositis and inclusion body myositis. The myositis-specific autoantibodies (MSAs) identify other and often more distinct clinical phenotypes, such as the antisynthetase syndrome with antisynthetase autoantibodies and frequent interstitial lung disease and anti-SRP and anti-HMGCR autoantibodies that identify necrotizing myopathy. The MSAs are important both to support myositis diagnosis and to identify subgroups with different patterns of extramuscular organ involvement such as interstitial lung disease. Another cornerstone in the diagnostic procedure is muscle biopsy to identify inflammation and to exclude noninflammatory myopathies. Treatment effect and prognosis vary by subgroup. To develop new and better therapies, validated classification criteria that identify distinct subgroups of myositis are critical. The lack of such criteria was the main rationale for the development of new classification criteria for IIMs, which are summarized in this review; the historical background regarding previous diagnostic and classification criteria is also reviewed. As the IIMs are rare diseases with a prevalence of 10 in 100 000 individuals, an international collaboration was essential, as was the interdisciplinary effort including experts in adult and paediatric rheumatology, neurology, dermatology and epidemiology. The new criteria have been developed based on data from more than 1500 patients from 47 centres worldwide and are based on clinically easily available variables.