The mucocutaneous and systemic phenotype of dermatomyositis patients with antibodies to MDA5 (CADM-140): a retrospective study

Clinical significance and new detection system of autoantibodies in myositis with interstitial lung disease

Anti-aminoacyl-tRNA synthetase (ARS) and anti-melanoma differentiation-associated gene 5 ( MDA5) antibodies are closely associated with interstitial lung disease in polymyositis and dermatomyositis. Anti-ARS-positive patients develop common clinical characteristics termed anti-synthetase syndrome and share a common clinical course, in which they respond well to initial treatment with glucocorticoids but in which disease tends to recur when glucocorticoids are tapered. Anti- MDA5 antibody is associated with rapidly progressive interstitial lung disease and poor prognosis, particularly in Asia. Therefore, intensive immunosuppressive therapy is required for anti- MDA5-positive patients from the early phase of the disease. New enzyme-linked immunosorbent assays to detect anti-ARS and anti- MDA5 antibodies have recently been established and are suggested to be efficient and useful. These assays are expected to be widely applied in daily practice.

Association of Antibodies to Interferon-Inducible Protein-16 With Markers of More Severe Disease in Primary Sjögren's Syndrome

OBJECTIVE

Interferon-inducible protein-16 (IFI16) is an intracellular DNA receptor involved in innate immunity. We evaluated the frequency, phenotypic characteristics, and clinical associations of anti-IFI16 antibodies in patients with primary Sjögren's syndrome (SS), and quantitated expression levels of IFI16 in SS and control salivary gland lysates.

METHODS

Anti-IFI16 antibodies were assayed by enzyme-linked immunosorbent assay using sera from patients with primary SS (n = 133) and from healthy controls (n = 47). Sera from systemic lupus erythematosus (SLE) patients (n = 132) were included as disease controls. Immunoprecipitation of in vitro transcription-translated IFI16 was used to determine which portion of IFI16 the antibodies recognized. Expression of IFI16 in salivary gland lysates was quantitated by immunoblotting.

RESULTS

Anti-IFI16 antibodies were present in the sera of 38 of 133 SS patients (29%) compared to 1 of 47 healthy controls (2.1%) (SS versus controls; P < 0.0002) and in 31 of 132 SLE controls (24%). In SS, anti-IFI16 antibodies were associated with an abnormal Schirmer's test (P = 0.003), hyperglobulinemia (P = 0.02), antinuclear antibody ≥1:320 (P = 0.01), germinal center-like structures in labial salivary gland lymphoid infiltrates (P = 0.01), and higher focus scores (3.4 versus 2.4; P = 0.005). High-titer IFI16 antibodies were directed against an epitope outside the N-terminus in 9 of 13 SS patients (69%). IFI16 was expressed in 4 of 5 (80%) of SS and 1 of 6 (17%) of control labial salivary glands.

CONCLUSION

Anti-IFI16 antibodies are a prominent specificity in primary SS and are associated with markers of severe disease. IFI16 is expressed at higher levels in SS salivary glands compared to controls. These high levels in disease target tissue may contribute to the ongoing anti-IFI16 immune response.

Clinical Utility of an Enzyme-Linked Immunosorbent Assay for Detecting Anti-Melanoma Differentiation-Associated Gene 5 Autoantibodies

Objective

Autoantibodies to melanoma differentiation-associated gene 5 (MDA5) are specifically expressed in patients with dermatomyositis (DM) and are associated with a subset of DM patients with rapidly progressive interstitial lung disease (RP-ILD). Here, we examined the clinical utility of a newly developed enzyme-linked immunosorbent assay (ELISA) system for detecting these antibodies.

Methods

Here we developed an improved ELISA for detecting anti-MDA5 antibodies. We then performed a multicenter clinical study involving 8 medical centers and enrolled 242 adult patients with polymyositis (PM)/DM, 190 with non-PM/DM connective tissue disease (CTD), 154 with idiopathic interstitial pneumonia (IIP), and 123 healthy controls. Anti-MDA5 antibodies in the patients’ serum samples were quantified using our newly developed ELISA, and the results were compared to those obtained using the gold-standard immunoprecipitation (IP) assay. In addition, correlations between the ELISA-quantified anti-MDA5 antibodies and clinical characteristics were evaluated.

Results

In patients with PM/DM, the anti-MDA5 antibody measurements obtained from the ELISA and IP assay were highly concordant; the ELISA exhibited an analytical sensitivity of 98.2%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 99.5% (compared to the IP assay). Anti-MDA5 antibodies were detected in 22.7% of the DM patients, but not in any of the patients with PM, non-PM/DM CTD, or IIP. Clinically amyopathic DM, RP-ILD, arthritis, and fever were more prevalent in DM patients who were anti-MDA5 antibody-positive than in those who were antibody-negative (P ≤ 0.0002 for all comparisons). In addition, anti-MDA5 antibody-positive patients with RP-ILD exhibited higher antibody levels than those without RP-ILD (P = 0.006).

Conclusion

Our newly developed ELISA can detect anti-MDA5 antibodies as efficiently as the gold standard IP assay and has the potential to facilitate the routine clinical measurement of anti-MDA5 antibodies in patients who suspected to have DM.

A New Immunodot Assay for Multiplex Detection of Autoantibodies in a Cohort of Italian Patients With Idiopathic Inflammatory Myopathies

BACKGROUND

Autoantibody detection has been assessed as tool for the diagnosis and the definition of idiopathic inflammatory myopathies (IIM). The aim of the study was to characterize the autoantibody profiling of a cohort of Italian patients with IIM.

METHODS

Sera of 53 adult patients with definite IIM, according to Bohan-Peter criteria, were tested for anti-nuclear autoantibodies (ANA), using indirect immunofluorescence (IIF) method, and for myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs), using two new commercial immunodot assays.

RESULTS

MSAs and/or MAAs were detected in 29 of 53 (54.7%) patients with IIM. Twenty-three patients (43.4%) were positive for at least one MSAs: 13 (24.5%) had anti-histidyl-tRNA synthetase autoantibodies (Jo1), 4 (7.5%) had other anti-aminoacyl-tRNA synthetases autoantibodies (anti-ARS), 1 (1.8%) had anti-transcription intermediary factor 1 gamma autoantibodies (anti-TIF1γ), 2 (3.7%) had anti-nuclear helicase protein Mi-2 autoantibodies (anti-Mi-2), 4 (7.5%) had anti-small ubiquitin like modifier activating enzyme heterodimer autoantibodies (anti-SAE). Moreover, 17 patients (32%) were positive for at least one MAAs. Coexisting MSAs and MAAs were observed in 9 of 53 (16.9%) patients, anti-Jo1/SS-A autoantibodies in most cases. Overall sensitivity of immunodot assays was 54.7%, the specificity was almost absolute. At cut-off value of 1:160, the sensitivity of ANA-IIF was 52.8%, increasing to 66% if cytoplasmatic fluorescence reaction was reported. Notably, two (5.7%) ANA-IIF negative patients had MSAs, detected only by immunodot assays.

CONCLUSION

It was possible to identify MSAs otherwise undetectable because of the use of new assays. Immunodot can reveal MSAs even when IIF results are inconclusive or, in some cases, ANA negative.

Autoantigens as Partners in Initiation and Propagation of Autoimmune Rheumatic Diseases

Systemic autoimmune diseases are characterized by specific targeting of a limited group of ubiquitously expressed autoantigens by the immune system. This review examines the mechanisms underlying their selection as immune targets. Initiation of autoimmune responses likely reflects the presentation of antigens with a distinct structure not previously encountered by the immune system, in a proimmune context (injury, malignancy, or infection). Causes of modified structure include somatic mutation and posttranslational modifications (including citrullination and proteolysis). Many autoantigens are components of multimolecular complexes, and some of the other components may provide adjuvant activity. Propagation of autoimmune responses appears to reflect a bidirectional interaction between the immune response and the target tissues in a mutually reinforcing cycle: Immune effector pathways generate additional autoantigen, which feeds further immune response. We propose that this resonance may be a critical principle underlying disease propagation, with specific autoantigens functioning as the hubs around which amplification occurs.

An Autopsy Case of Anti-melanoma Differentiation-associated Gene-5 Antibody-positive Clinical Amyopathic Dermatomyositis Complicated by Rapidly Progressive Interstitial Lung Disease

A 62-year-old man presented with heliotrope rash, Gottron's sign, and mild muscle weakness. Both of his lung fields showed interstitial changes that worsened rapidly. He was diagnosed with clinical amyopathic dermatomyositis with rapidly progressive interstitial lung disease. The patient died of respiratory failure, despite the administration of immunosuppressive therapy. Autopsy revealed diffuse alveolar damage. An antibody analysis, which was performed postmortem, detected the presence of anti-melanoma differentiation-associated gene (MDA)-5 antibodies. Clinicians should note the clinical, radiologic, and serologic findings to predict anti-MDA-5 antibody-associated rapidly progressive interstitial lung disease.

Spectrum of Muscle Histopathologic Findings in Forty-Two Scleroderma Patients With Weakness

OBJECTIVE

To determine if distinct muscle pathologic features exist in scleroderma subjects with weakness.

METHODS

This retrospective study included weak scleroderma subjects with muscle biopsies available for review. Biopsies were systematically assessed for individual pathologic features, including inflammation, necrosis, fibrosis, and acute neurogenic atrophy. Based on the aggregate individual features, biopsies were assigned a histopathologic category of polymyositis, dermatomyositis, necrotizing myopathy, nonspecific myositis, "acute denervation," "fibrosis only," or "other." Clinical data analyzed included autoantibody profiles, scleroderma subtype and disease duration, Medsger muscle severity scores, creatine kinase, electromyography, and muscle magnetic resonance imaging.

RESULTS

A total of 42 subjects (79% female and 64% diffuse scleroderma) were included in this study. Necrosis (67%), inflammation (48%), acute neurogenic atrophy (48%), and fibrosis (33%) were the most prevalent pathologic features. The presence of fibrosis was strongly associated with anti-PM-Scl antibodies. Histopathologic categories included nonspecific myositis (36%), necrotizing myopathy (21%), dermatomyositis (7%), "acute denervation" (7%), "fibrosis only" (7%), and polymyositis (5%). Disease duration of scleroderma at the time of muscle biopsy was shorter in polymyositis than other histopathologic categories. Patients with anti-PM-Scl and Scl-70 antibodies also had a shorter disease duration than those with other autoantibody profiles.

CONCLUSION

Nonspecific myositis and necrotizing myopathy were the most common histopathologic categories in weak scleroderma subjects. Surprisingly, nearly half of the subjects studied had histologic evidence of acute motor denervation (acute neurogenic atrophy); this has not been previously reported. Taken together, these observations suggest that a variety of pathologic mechanisms may underlie the development of myopathy in scleroderma.

Serological subsets of juvenile idiopathic inflammatory myopathies--an update

In this review we explore the different characteristics of the serological phenotypes identified in juvenile-onset myositis and consider how the serological sub-classification of patients with juvenile myositis can be advantageous both in terms of reaching what can be a difficult diagnosis and informing on prognosis. Recent studies have described the autoantibody associated disease phenotypes and outcome for those with juvenile-onset disease and include analyses of large juvenile-onset myositis cohorts. Here we describe the autoantibody associated disease features for patients within juvenile-onset myositis in detail and discuss the expanding opportunities and strategies for myositis specific autoantibody testing in clinical practice.

Biomarkers in rheumatic diseases: how can they facilitate diagnosis and assessment of disease activity?

Serological and proteomic biomarkers can help clinicians diagnose rheumatic diseases earlier and assess disease activity more accurately. These markers have been incorporated into the recently revised classification criteria of several diseases to enable early diagnosis and timely initiation of treatment. Furthermore, they also facilitate more accurate subclassification and more focused monitoring for the detection of certain disease manifestations, such as lung and renal involvement. These biomarkers can also make the assessment of disease activity and treatment response more reliable. Simultaneously, several new serological and proteomic biomarkers have become available in the routine clinical setting--for example, a protein biomarker panel for rheumatoid arthritis and a myositis antibody panel for dermatomyositis and polymyositis. This review will focus on commercially available antibody and proteomic biomarkers in rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis (scleroderma), dermatomyositis and polymyositis, and axial spondyloarthritis (including ankylosing spondylitis). It will discuss how these markers can facilitate early diagnosis as well as more accurate subclassification and assessment of disease activity in the clinical setting. The ultimate goal of current and future biomarkers in rheumatic diseases is to enable early detection of these diseases and their clinical manifestations, and to provide effective monitoring and treatment regimens that are tailored to each patient's needs and prognosis.

[Juvenile dermatomyositis and new autoantibodies: Cases and review]

Juvenile dermatomyositis (JDM) is the most common inflammatory myopathy in children. Its diagnosis is usually made on a clinical basis following the criteria of Bohan and Peter (1975). Recently, the presence of myositis-specific autoantibodies (MSAs) have started to be associated with specific outcome in adult patients; the diagnosis and prognosis value of these autoantibodies remains to be identified in children. We report four cases of JDM with MSAs focusing on clinical, biological, and radiological manifestations, and then we describe associated treatment. The cohort comprises four girls with an average age of 8.5 years. The time to diagnosis was 1 week to 4 months. For these patients, the immunologic study found one patient positive for the MDA5 antibody (or CADM 140), one positive for the TIF1γ antibody (or p155/140), and two patients positive for the NXP2 antibody (or p140/MJ). Each patient showed specific and characteristic cutaneous manifestations. For example, the girl positive for the TIF1γ antibody presented the most severe skin disease with urticaria, face edema, and vascularity of the neck and shoulders. However, regarding muscular features, proximal weakness was present in most of the cohort, except for the child positive for the MDA5 antibody, who presented no sign of muscular disease at the beginning with low CK levels. Importantly, acute pancreatitis also affected this patient. Concerning radiological indications, muscular MRI evidenced hyperinflammation, a sign of diffuse myositis, in all these patients. Treatments consisted in corticosteroids together with methotrexate or mycofenolate mofetil associated or not with intravenous immunoglobulin therapy. This report highlights the importance of systematic detection and analysis of MSA in diagnosis and characterization of JDM, and describes a new approach that would allow more focused treatments and be a useful predictor of clinical complications and prognosis in JDM-affected subjects.

MDA5-positive dermatomyositis: an uncommon entity in Europe with variable clinical presentations

Clinically amyopathic dermatomyositis (CADM), described almost 50 years ago, is defined on the basis of still not validated criteria and characterized by skin findings almost without muscle weakness. Autoantibodies directed against the cytosolic pathogen sensor MDA5 (CADM 140) can mark this subtype of dermatomyositis which has been reported to associate, in particular ethnic groups, with severe progressive interstitial lung disease, poor prognosis and an hyperferritinemic status resembling hemophagocytic-like syndromes. MDA5 may be relevant in that Interferon-signature claimed to characterize inflammatory myopathies and dermatomyosits itself, but its role is not clear. However, the titre of anti-MDA5 autoantibodies seems to correlate with the outcome. In Caucasian populations the association between anti-MDA5 positive CADM and rapidly progressive interstitial lung disease seems to be weaker, but the limited numbers of patients described so far could explain the lack of statistical significance. As a fact, European patients with circulating anti-MDA5 autoantibodies may be clinically inhomogeneous and exhibit different rates of severity. The two patients affected by anti-MDA5 positive dermatomyositis described hereafter provide a clear example of the extreme variability of the disease in terms of laboratory findings and clinical features.

Abnormalities of Skin and Cutaneous Appendages in Neuromuscular Disorders

OBJECTIVES

A thorough evaluation of the skin and its appendages is frequently outside the area of expertise of the neurologist who deals with neuromuscular disorders. However, the skin is more frequently affected in neuromuscular disorders and deserves more attention than so far acknowledged.

METHODS

Review of publications by searching Medline dealing with skin disorders in neuromuscular disorders.

RESULTS

Skin abnormalities are most frequently found in patients with dermatomyositis, myotonic dystrophies, mitochondrial disorders, muscular dystrophies, and neuropathies. The hairs and the sweat glands are the appendages most frequently affected in neuromuscular disorders. In myotonic dystrophies and mitochondrial disorders there are indications that the rate of skin neoplasms is increased compared with the general population.

CONCLUSIONS

Skin lesions in neuromuscular disorders are not unusual. Neurologists should be aware of the cutaneous implications of neuromuscular disorders and should take a thorough history relative to cutaneous manifestations and complete a comprehensive investigation of the skin and its appendages. If there is evidence of a dermatological problem in a neuromuscular disorder, a dermatologist should be consulted. Dermatological involvement in neuromuscular disorders may contribute to the diagnosis of neuromuscular disorders and may help to differentiate between various entities. The skin should become a focus of the neurologist as well.

The Prevalence of Individual Histopathologic Features Varies according to Autoantibody Status in Muscle Biopsies from Patients with Dermatomyositis

OBJECTIVE

Individual dermatomyositis (DM)-associated autoantibodies are associated with distinct clinical phenotypes. This study was undertaken to explore the association of these autoantibodies with specific muscle biopsy features.

METHODS

DM subjects with a muscle biopsy reviewed at Johns Hopkins had sera screened for autoantibodies recognizing Mi-2, transcriptional intermediary factor 1-γ (TIF1-γ), NXP2, MDA5, Ro52, PM-Scl, and Jo1. We also included anti-Jo1–positive patients with polymyositis (PM) who had a biopsy read at Johns Hopkins. Analyzed histological features included perifascicular atrophy, perivascular inflammation, mitochondrial dysfunction, primary inflammation, and myofiber necrosis. Duration of disease, biopsy location, and treatment at biopsy were also analyzed.

RESULTS

We studied 91 DM and 7 anti-Jo1–positive patients with PM. In univariate analyses, TIF1-γ+ patients had more mitochondrial dysfunction (47% vs 18%; p = 0.05), NXP2+ patients had less primary inflammation (0% vs 28%; p = 0.01), Mi-2+ patients had more primary inflammation (50% vs 19%; p = 0.03), and PM-Scl+ patients had more primary inflammation (67% vs 18%; p = 0.004) than those who were negative for each autoantibody. Although reliability was limited because of small sample numbers, multivariate analysis confirmed that TIF1-γ+ patients had more mitochondrial dysfunction [prevalence ratio (PR) 2.6, 95% CI 1.0–6.5, p = 0.05] and PM-Scl+ patients had more primary inflammation (PR 5.2, 95% CI 2.0–13.4; p = 0.001) independent of disease duration at biopsy, biopsy site, and treatment at biopsy. No differences in muscle biopsy features were noted between anti-Jo1–positive patients diagnosed with DM and PM.

CONCLUSION

The prevalence of different histological features varies according to autoantibody status in DM. Muscle biopsy features are similar in anti-Jo1 patients with and without a rash.

The evolving spectrum of polymyositis and dermatomyositis--moving towards clinicoserological syndromes: a critical review

The idiopathic inflammatory myopathies: polymyositis (PM) and dermatomyositis (DM) have been historically defined by broad clinical and pathological criteria. These conditions affect both adults and children with clinical features including muscle weakness, skin disease and internal organ involvement. Over the last few years, it has become increasingly apparent that using a clinico-serological approach, both DM and PM can be defined into more homogeneous subsets. A large number of antibodies are directed against cytoplasmic or nuclear components involved in key regulatory intra-cellular processes including protein synthesis, translocation and gene transcription within this disease spectrum. In addition, these autoantibodies are found in patients with clinical features other than myositis, in particular 'idiopathic' interstitial pneumonia emphasizing that these patients may in fact be a formes-frustes of autoimmune connective tissue disease. Other important findings are the identification of specific autoantibodies in both cancer-associated dermatomyositis, clinically amyopathic dermatomyositis and juvenile dermatomyositis, which previously were classically described as antibody-negative clinical subsets. Finally, work has highlighted how target autoantigens identified in the myositis-connective tissue disease overlap share common cellular mechanisms, which provides us with further insights into disease pathogenesis.

Recent Treatment of Interstitial Lung Disease with Idiopathic Inflammatory Myopathies

Interstitial lung disease (ILD) is a prognostic factor for poor outcome in polymyositis (PM)/dermatomyositis (DM). The appropriate management of ILD is very important to improve the prognosis of patients with PM/DM. ILD activity and severity depend on the disease subtype. Therefore, clinicians should determine therapeutic strategies according to the disease subtype in each patient with PM/DM. Anti-melanoma differentiation-associated gene 5 antibody and hyperferritinemia predict the development and severity of rapidly progressive (RP) ILD, particularly in East Asian patients. Combination therapy with corticosteroids, intravenous cyclophosphamide pulse, and calcineurin inhibitors should be administered in RP-ILD. In contrast, patients with anti-aminoacyl-tRNA synthetase (ARS) show better responses to corticosteroids alone. However, ILDs with anti-ARS often display disease recurrence or become refractory to corticosteroid monotherapy. Recent studies have demonstrated that the administration of tacrolimus or rituximab in addition to corticosteroids may be considered in ILD patients with anti-ARS. Large-scale, multicenter randomized clinical trials should be conducted in the future to confirm that the aforementioned agents exhibit efficacy in ILD patients with PM/DM. The pathophysiology of ILD with PM/DM should also be elucidated in greater detail to develop effective therapeutic strategies for patients with ILD in PM/DM.

The Prevalence of Individual Histopathologic Features Varies according to Autoantibody Status in Muscle Biopsies from Patients with Dermatomyositis

Objective.

Individual dermatomyositis (DM)-associated autoantibodies are associated with distinct clinical phenotypes. This study was undertaken to explore the association of these autoantibodies with specific muscle biopsy features.

Methods.

DM subjects with a muscle biopsy reviewed at Johns Hopkins had sera screened for autoantibodies recognizing Mi-2, transcriptional intermediary factor 1-γ (TIF1-γ), NXP2, MDA5, Ro52, PM-Scl, and Jo1. We also included anti-Jo1–positive patients with polymyositis (PM) who had a biopsy read at Johns Hopkins. Analyzed histological features included perifascicular atrophy, perivascular inflammation, mitochondrial dysfunction, primary inflammation, and myofiber necrosis. Duration of disease, biopsy location, and treatment at biopsy were also analyzed.

Results.

We studied 91 DM and 7 anti-Jo1–positive patients with PM. In univariate analyses, TIF1-γ+ patients had more mitochondrial dysfunction (47% vs 18%; p = 0.05), NXP2+ patients had less primary inflammation (0% vs 28%; p = 0.01), Mi-2+ patients had more primary inflammation (50% vs 19%; p = 0.03), and PM-Scl+ patients had more primary inflammation (67% vs 18%; p = 0.004) than those who were negative for each autoantibody. Although reliability was limited because of small sample numbers, multivariate analysis confirmed that TIF1-γ+ patients had more mitochondrial dysfunction [prevalence ratio (PR) 2.6, 95% CI 1.0–6.5, p = 0.05] and PM-Scl+ patients had more primary inflammation (PR 5.2, 95% CI 2.0–13.4; p = 0.001) independent of disease duration at biopsy, biopsy site, and treatment at biopsy. No differences in muscle biopsy features were noted between anti-Jo1–positive patients diagnosed with DM and PM.

Conclusion.

The prevalence of different histological features varies according to autoantibody status in DM. Muscle biopsy features are similar in anti-Jo1 patients with and without a rash.

Pilot study to determine whether transient receptor potential melastatin type 8 (TRPM8) antibodies are detected in scleroderma

OBJECTIVES

A key mediator in cold-sensation is the protein transient receptor potential melastatin 8 (TRPM8), which is expressed on sensory nerves and cutaneous blood vessels. These receptors are activated by cold temperatures and play a key role in body thermoregulation. Cold sensitivity and Raynaud's phenomenon are frequent clinical features in scleroderma, and are thought to be secondary to a local defect in cutaneous thermoregulation. We investigated whether autoantibodies targeting TRPM8 were present in the sera of patients with scleroderma as evidence for a possible mechanism for an acquired immune mediated defect in thermoregulation.

METHODS

Sera from 50 well-characterised scleroderma patients with Raynaud's phenomenon were studied. TRPM8 autoantibodies were assayed as follows: 1. immunoprecipitation with 35S-methionine-labelled TRPM8 generated by in vitro transcription and translation, 2. immunoblotting lysates made from cells transiently transfected with TRPM8 cDNA, 3. Immunoprecipitation of TRPM8 transfected lysates with detection by blotting and 4. flow cytometry.

RESULTS

Fifty scleroderma patients with Raynaud's phenomenon (41 female, 39 Caucasian, 23 with limited scleroderma, and 20 with history of cancer) were studied. Four different methods to assay for TRPM8 antibodies were set up, optimised and validated using commercial antibodies. All 50 scleroderma patients' sera were assayed using each of the above methods, and all were negative for TRPM8 autoantibodies.

CONCLUSIONS

Antibodies against TRPM8 are not found in scleroderma patient sera, suggesting that the abnormal cold sensitivity and associated abnormal vascular reactivity in scleroderma patients is not the result of an immune process targeting TRPM8.

Cutaneous ulceration in dermatomyositis: association with anti-melanoma differentiation-associated gene 5 antibodies and interstitial lung disease

OBJECTIVE

To identify clinical and serologic correlates of cutaneous ulcers in dermatomyositis (DM).

METHODS

We retrospectively examined a cohort of 152 DM patients. We compared the features of patients with ulcers to those without ulcers using chi-square or Fisher's exact tests and used univariate and multivariate logistic regression models to assess the association between ulcers and clinical features such as malignancy, interstitial lung disease (ILD), and amyopathic disease.

RESULTS

Forty-three patients (28%) had cutaneous ulcers. Nearly half the patients had ulcers present in more than 1 location: 24 (56%) had ulcers over the extensor surfaces of joints, 18 (42%) at the digital pulp or periungual areas, and 25 (58%) had ulcers located elsewhere. In univariate analysis ulcers were associated with Asian race, but not with other clinical and demographic features, including malignancy or ILD. In multivariate analysis ulcers were significantly associated with anti-melanoma differentiation gene 5 (anti-MDA5) antibodies (odds ratio 10.14, 95% confidence interval 1.95-52.78; P = 0.0059) and this was greatest for ulcers located at the digital pulp. In patients with cutaneous ulcers, ILD risk was specifically increased only in patients with anti-MDA5-positive antibodies.

CONCLUSION

We confirmed the strong association between anti-MDA5 antibodies and cutaneous ulcers, with the novel finding that the association of cutaneous ulcers with ILD depends upon the presence of anti-MDA5 antibodies. DM patients who display this cutaneous phenotype should undergo appropriate evaluation for ILD.

Interstitial lung disease associated with the idiopathic inflammatory myopathies and the antisynthetase syndrome: recent advances

PURPOSE OF REVIEW

To highlight recent advances in understanding the clinical spectrum, pathogenesis, and treatment of interstitial lung disease associated with inflammatory myositis and the antisynthetase syndrome.

RECENT FINDINGS

In recent years, serologic tests to identify the less common antisynthetase antibodies and the anti-MDA-5 antibody have become commercially available. As a result, several large, retrospective analyses have illustrated both the pulmonary and non-pulmonary features associated with the antisynthetase syndrome and myositis-related interstitial lung disease. Notably, there is now a better appreciation for the heterogeneity of these syndromes and the prognostic value in accurately identifying the associated autoantibodies. Human cytokine profiling and murine models of muscle inflammation suggest that tRNA synthetases themselves may act to trigger an initial innate immune response, thus offering new insights into the pathophysiology of these diseases. Finally, although randomized clinical trials in patients with myositis-associated interstitial lung disease have not occurred, new observational studies suggest that cyclosporine, tacrolimus, and rituximab may be effective treatment options.

SUMMARY

Recent research has provided a better understanding of the phenotype and prognosis that define interstitial lung disease in the setting of myositis and the antisynthetase syndrome. Although several therapeutic agents demonstrate promise, randomized trials are needed in order to establish the best clinical approach in these patients. Furthermore, additional research into the pathophysiology of this disease will be necessary to develop newer, more targeted therapeutics.

Amyophatic dermatomyositis presenting as a flagellated skin eruption with positive MDA5 antibodies and thyroid cancer: a real association?

Amyopathic dermatomyositis (ADM) is characterized clinically by typical skin lesions with hypomyopathy or no muscular involvement. ADM has been recently reported to be complicated by rapidly progressive interstitial lung disease (ILD), especially in patients with positive antibodies against melanoma differentiation-associated gene 5 (MDA5). These patients may have a low risk of cancer, but no clinical, histological or laboratory markers completely specific for paraneoplastic DM have been identified to date. We report a case of flagellate erythema as the initial presentation of ADM associated with ILD, positive MDA5 antibodies and a concomitant diagnosis of thyroid cancer. We discuss the unusual clinical features and associations that make this case particularly interesting.

Anti-MDA5 positive clinically amyopathic dermatomyositis presenting with severe cardiomyopathy

BACKGROUND

Anti-MDA5 (Melanoma differentiation-associated gene 5) positive dermatomyositis is a new variant of clinically amyopathic dermatomyositis that presents with characteristic mucocutaneous findings and is associated with a higher risk of developing rapidly progressive interstitial lung disease. Because its presentation differs from that of classical dermatomyositis, this entity can be a diagnostic challenge for the clinician.

METHODS & RESULTS

We present the case of a 55-year-old male with a 7-month history of chill sensation, constitutional symptoms and polyarthralgia. Within 3 months, the patient developed progressive heart failure with dyspnoea and orthopnoea, together with characteristic cutaneous lesions. Skin biopsies demonstrated thrombosis of small and medium-sized arteries in the reticular dermis, together with an evolved lobular panniculitis and prominent mucin deposits.

CONCLUSIONS

Clinicians should be aware of the characteristic clinical and histopathologic presentation of this variant of dermatomyositis to establish an early diagnosis. Further evidence is needed to clarify the risk of cardiac involvement in this subset of patients.

A case of anti-MDA5-positive rapidly progressive interstitial lung disease in a patient with clinically amyopathic dermatomyositis ameliorated by rituximab, in addition to standard immunosuppressive treatment

Rapidly progressive interstitial lung disease (RP-ILD) in patients with clinically amyopathic dermatomyositis (CADM) associated with antibodies to melanoma differentiation-associated gene5 (MDA5) results in a high mortality rate. We experienced a case of anti-MDA5-positive RP-ILD of CADM which showed a response to rituximab, although there was no significant effect due to standard immunosuppressive treatment. This case suggests that rituximab has the potential to offer an effective agent for the treatment of anti-MDA5-positive RP-ILD of CADM.

Distinctive cutaneous and systemic features associated with antitranscriptional intermediary factor-1γ antibodies in adults with dermatomyositis

BACKGROUND

Antibodies against transcriptional intermediary factor (TIF)-1γ are associated with malignancy in dermatomyositis (DM). Identification of clinical findings associated with anti-TIF-1γ antibodies in DM is a high priority for both patient diagnosis and risk assessment.

OBJECTIVE

We sought to define the clinical phenotype of patients with anti-TIF-1γ DM.

METHODS

Using a novel, sensitive, and specific assay for anti-TIF-1γ antibodies, we retrospectively tested plasma from 134 adult patients with DM and examined associations between anti-TIF-1γ antibodies and particular clinical and laboratory features.

RESULTS

In all, 55 (41%) patients had autoantibodies to TIF-1γ. Anti-TIF-1γ positive patients were less likely to have systemic features including interstitial lung disease, Raynaud phenomenon, and arthritis/arthralgia. Patients with TIF-1γ autoantibodies had more extensive skin involvement, and some patients manifested characteristic findings including palmar hyperkeratotic papules, psoriasis-like lesions and a novel finding of hypopigmented and telangiectatic ("red on white") patches.

LIMITATIONS

This was a retrospective study from a single tertiary referral center.

CONCLUSION

TIF-1γ is the most commonly targeted DM-specific autoantigen in adults in a large US cohort. Although these patients tend to have less systemic involvement, their skin disease is often extensive and characteristic. Recognition of cutaneous findings in anti-TIF-1γ positive patients may allow more accurate and timely diagnosis and effective treatment of patients with DM.

Pulmonary complications of inflammatory myopathy

Pulmonary complications cause significant morbidity and mortality in the idiopathic inflammatory myopathies. Advances in biomarker discovery have facilitated clinical phenotyping, allowing investigators to better define at-risk patient subsets and to potentially gauge disease activity. This serologic characterization has complemented more traditional assessment tools. Pharmacologic management continues to rely on the use of corticosteroids, often in combination with additional immunosuppressive agents. The rarity of myositis-associated interstitial lung disease and lack of controlled trials have limited analyses of treatment efficacy, mandating the development of standardized outcome measures and improvement of data sharing between disciplines.

[Dermatomyositis-specific antibodies]

BACKGROUND

Idiopathic inflammatory myopathies are chronic systemic autoimmune diseases characterized by symmetrical proximal muscle weakness. The clinicopathological subdivision nowadays appears to be obsolete which is why the immunoserological classification has been developed.

OBJECTIVES

Dermatomyositis represents one the most important subsets of idiopathic inflammatory myopathy and dermatomyositis-specific autoantibodies play a significant role in this subset. The aim of this article was to present these autoantibodies with the help of the literature.

METHODS

This article presents the most important information about dermatomyositis including not only the classical anti-Mi-2 autoantibody but also the recently detected anti-TIF1γ, anti-NXP2, anti-SAE and anti-MDA5 autoantibodies. The focus is on the frequency of these autoantibodies, the associated symptoms in adult and juvenile dermatomyositis cases and some special aspects from the literature.

RESULTS

All of the studies confirmed that these autoantibodies are particularly detectable in dermatomyositis. The results from the literature have recently shown that the frequency of the autoantibodies detected in juvenile cases is higher than the frequency of traditional autoantibodies (e.g. anti-Jo-1, anti-Mi-2 and anti-SRP).

CONCLUSION

It is useful to detect these autoantibodies in order to be able to make a better assessment of the clinical symptoms and prognosis during the course of the disease.

The role of type I interferons and other cytokines in dermatomyositis

Much work has been done to unveil the mechanisms behind the pathogenesis of dermatomyositis (DM) - mainly those involving certain pathogenic cytokines, termed "pathokines" as the principal cytokines involved. Recently, it has become clear that a group of cytokines known as type I interferons (IFN-Is) play a significant role in the development of DM. We review the literature published between 1946 and 2014 using an Ovid Medline database search to provide an update on the role of IFN-Is and other cytokines in the pathogenesis of DM. We provide information about the genes and proteins induced by IFN-Is and potential mechanisms by which these downstream products relate to clinical disease activity. We also explore findings of other autoimmune phenomena that may contribute to disease onset and activity including T-helper 17 (Th17) cells and associated interleukins, as well as autoantibodies. Finally, we provide a brief update on current treatment options for DM as well as some new immunomodulatory treatment modalities in development.

A case of sarcoidosis with interstitial lung disease mimicking clinically amyopathic dermatomyositis and rapidly progressive interstitial lung disease

Here, we report a patient with sarcoidosis who developed edematous erythema and interstitial lung disease. At the initial visit, clinically amyopathic dermatomyositis (CADM) with rapidly progressive interstitial lung disease (RP-ILD) was suspected because he had progressive dyspnea but no muscle weakness. The presence of anti-CADM-140/MDA5 autoantibodies was immediately assessed to facilitate a precise diagnosis, with negative results. Thereafter, skin and transbronchial lung biopsies revealed noncaseating granuloma with Langhans giant cells in both specimens, leading to a diagnosis of sarcoidosis. In this case, clinical features of skin and lung were unable to distinguish DM (including CADM) from sarcoidosis, but the lack of anti-CADM-140/MDA5 antibody was useful for differentiating CADM with RP-ILD mimicking sarcoidosis from bona fide sarcoidosis.

Myositis registries and biorepositories: powerful tools to advance clinical, epidemiologic and pathogenic research

PURPOSE OF REVIEW

Clinical registries and biorepositories have proven extremely useful in many studies of diseases, especially rare diseases. Given their rarity and diversity, the idiopathic inflammatory myopathies, or myositis syndromes, have benefited from individual researchers' collections of cohorts of patients. Major efforts are being made to establish large registries and biorepositories that will allow many additional studies to be performed that were not possible before. Here, we describe the registries developed by investigators and patient support groups that are currently available for collaborative research purposes.

RECENT FINDINGS

We have identified 46 myositis research registries, including many with biorepositories, which have been developed for a wide variety of purposes and have resulted in great advances in understanding the range of phenotypes, clinical presentations, risk factors, pathogenic mechanisms, outcome assessment, therapeutic responses, and prognoses. These are now available for collaborative use to undertake additional studies. Two myositis patient registries have been developed for research, and myositis patient support groups maintain demographic registries with large numbers of patients available to be contacted for potential research participation.

SUMMARY

Investigator-initiated myositis research registries and biorepositories have proven extremely useful in understanding many aspects of these rare and diverse autoimmune diseases. These registries and biorepositories, in addition to those developed by myositis patient support groups, deserve continued support to maintain the momentum in this field as they offer major opportunities to improve understanding of the pathogenesis and treatment of these diseases in cost-effective ways.

Identification of clinical features and autoantibodies associated with calcinosis in dermatomyositis

IMPORTANCE

Prior studies have estimated that up to 20% of adults with dermatomyositis (DM) have calcinosis, which can lead to significant morbidity. Identification of risk factors may provide a better understanding of the pathogenesis and ultimately therapy for this difficult clinical problem. Risk factors for calcinosis in adults with DM have not been extensively studied.

OBJECTIVES

To determine the prevalence of calcinosis and to identify associated clinical features in a cohort of extensively phenotyped adults with DM.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional study of 126 patients diagnosed as having DM from January 1, 2006, through January 1, 2013, was performed. Patients were adults (≥18 years of age) attending the Stanford University Medical Center clinic.

MAIN OUTCOMES AND MEASURES

Calcinosis, defined as the presence of calcium deposition in the skin and subcutaneous tissues on physical examination.

RESULTS

Fourteen patients (11.1%) had calcinosis, with the extremities most commonly involved. Patients with vs those without calcinosis had a longer disease duration (median, 6.9 years; range, 2.4-18.1; vs median, 3.9 years; range, 0.2-19.2 years; P = .003) and more fingertip ulcers (50.0% vs 9.3%, P < .001). An association between calcinosis and both interstitial lung disease and anti-MDA-5 autoantibodies was identified, but this association did not persist in multivariate models that adjusted for fingertip ulcers. Fingertip ulcers and disease duration were strongly associated with calcinosis in all multivariate models, independent of the underlying autoantibody present. Autoantibodies to NXP-2 were associated with calcinosis (odds ratio, 15.52; 95% CI, 2.01-119.90), whereas anti-transcriptional intermediary factor 1-γ antibodies were protective (odds ratio, 0.2; 95% CI, 0.01-0.99) in multivariate analyses that adjusted for fingertip ulcers and other covariates.

CONCLUSIONS AND RELEVANCE

Calcinosis was a relatively uncommon clinical feature in our cohort of adults with DM. Our data suggest that calcinosis is positively associated with longer disease duration, fingertip ulcers, and NXP-2 autoantibodies and negatively associated with transcriptional intermediary factor 1-γ antibodies. A common vascular mechanism may underlie the development of both calcinosis and fingertip ulcers in patients with DM.

Autoantibodies against TIF-1-γ and CADM-140 in Spanish patients with clinically amyopathic dermatomyositis (CADM): clinical significance and diagnostic utility

BACKGROUND

Patients with clinically amyopathic dermatomyositis (CADM) appear to be at risk for developing cancer and interstitial lung diseases, but population data to confirm this hypothesis are limited. Moreover, CADM presents cutaneous and histological findings that may overlap with subacute cutaneous lupus erythematosus (SCLE).

OBJECTIVES

To determine the association between myositis-specific autoantibodies, myositis-associated autoantibodies and CADM in Spanish patients. In addition, to study the usefulness of these autoantibodies in the differential diagnosis between CADM and SCLE.

METHODS

Serum samples were tested for myositis-specific autoantibodies and myositis-associated autoantibodies through immunoprecipitation and other standardized methods.

RESULTS

Anti-CADM-p140 and anti-p155 antibodies were the only myositis-specific autoantibodies found and were associated with interstitial lung diseases and cancer respectively. No myositis-associated autoantibodies were found in CADM. Moreover, clinical subsets and proportions seemed to differ from Asian cohorts, where anti-CADM-p140 is considered a CADM hallmark antibody and a risk factor for the development of interstitial lung disease. Interestingly, anti-SSA was highly associated with SCLE, whereas no myositis-specific autoantibodies were found in this entity.

LIMITATIONS OF THE STUDY

Association between CADM and myositis-specific autoantibodies and differences between CADM and SCLE were tested on a relatively small cohort of patients.

CONCLUSION

There is an association between cancer-associated myositis and interstitial lung diseases and their hallmark autoantibodies in our cohort. In addition, the combined determination of myositis-specific autoantibodies and SSA autoantibodies may help to accurately discriminate SCLE from CADM.

Anti-MDA5 autoantibodies in juvenile dermatomyositis identify a distinct clinical phenotype: a prospective cohort study

INTRODUCTION

The aim of this study was to define the frequency and associated clinical phenotype of anti-MDA5 autoantibodies in a large UK based, predominantly Caucasian, cohort of patients with juvenile dermatomyositis (JDM).

METHODS

Serum samples and clinical data were obtained from 285 patients with JDM recruited to the UK Juvenile Dermatomyositis Cohort and Biomarker Study. The presence of anti-MDA5 antibodies was determined by immunoprecipitation and confirmed by ELISA using recombinant MDA5 protein. Results were compared with matched clinical data, muscle biopsies (scored by an experienced paediatric neuropathologist) and chest imaging (reviewed by an experienced paediatric radiologist).

RESULTS

Anti-MDA5 antibodies were identified in 7.4% of JDM patients and were associated with a distinct clinical phenotype including skin ulceration (P = 0.03) oral ulceration (P = 0.01), arthritis (P <0.01) and milder muscle disease both clinically (as determined by Childhood Myositis Assessment Score (P = 0.03)) and histologically (as determined by a lower JDM muscle biopsy score (P <0.01)) than patients who did not have anti-MDA5 antibodies. A greater proportion of children with anti-MDA5 autoantibodies achieved disease inactivity at two years post-diagnosis according to PRINTO criteria (P = 0.02). A total of 4 out of 21 children with anti-MDA5 had interstitial lung disease; none had rapidly progressive interstitial lung disease.

CONCLUSIONS

Anti-MDA5 antibodies can be identified in a small but significant proportion of patients with JDM and identify a distinctive clinical sub-group. Screening for anti-MDA5 autoantibodies at diagnosis would be useful to guide further investigation for lung disease, inform on prognosis and potentially confirm the diagnosis, as subtle biopsy changes could otherwise be missed.

Meta-analysis of the association of dermatomyositis and polymyositis with cancer

BACKGROUND

Although some features of dermatomyositis (DM) and polymyositis (PM) have been reported as possible prognostic indicators for cancer development, previous studies were small in size and were unable to establish a definitive relationship between neoplasms and DM and PM.

OBJECTIVES

To evaluate risk factors for developing malignancies in patients with DM and PM.

METHODS

Meta-analysis of the studies reported in the literature was performed to unveil risk factors for developing cancer among patients with DM and PM. The included studies were either cohort or retrospective case-control studies with information on cancer status. Risk for malignancy was determined as the odds ratio (OR) or weighted mean difference (WMD) with a 95% confidence interval (CI), determined by fixed and random effects models. Stata 10.0 software was used to identify possible publication bias.

RESULTS

Twenty studies with 380 patients and 1575 controls were included in the analysis. The factors that may increase the risk of cancer in patients with DM and PM were older age (WMD 11·41, 95% CI 9·84-12·98), male sex (OR 1·92, 95% CI 1·49-2·48), cutaneous necrosis (OR 5·52, 95% CI 3·49-8·74) and dysphagia (OR 2·41, 95% CI 1·50-3·86), whereas those that may provide protection against cancer included arthritis (OR 0·38, 95% CI 0·24-0·61) and interstitial lung disease (OR 0·32, 95% CI 0·20-0·51).

CONCLUSIONS

Our data suggest that age, sex, cutaneous necrosis, dysphagia, arthritis and lung complications may influence susceptibility to cancer in patients with DM and PM.