Antimelanoma differentiation-associated protein 5 antibody level is a novel tool for monitoring disease activity in rapidly progressive interstitial lung disease with dermatomyositis

Dermatomyositis With Anti-MDA5 Antibodies: Bioclinical Features, Pathogenesis and Emerging Therapies

Anti-MDA5 dermatomyositis is a rare systemic autoimmune disease, historically described in Japanese patients with clinically amyopathic dermatomyositis and life-threatening rapidly progressive interstitial lung disease. Subsequently, the complete clinical spectrum of the disease was enriched by skin, articular and vascular manifestations. Depending on the predominance of these symptoms, three distinct clinical phenotypes with different prognosis are now defined. To date, the only known molecular component shared by the three entities are specific antibodies targeting MDA5, a cytosolic protein essential for antiviral host immune responses. Several biological tools have emerged to detect these antibodies, with drawbacks and limitations for each of them. However, the identification of this highly specific serological marker of the disease raises the question of its role in the pathogenesis. Although current knowledge on the pathogenic mechanisms that take place in the disease are still in their enfancy, several lines of evidence support a central role of interferon-mediated vasculopathy in the development of skin and lung lesions, as well as a possible pathogenic involvement of anti-MDA5 antibodies. Here, we review the clinical and biological evidences in favor of these hypothesis, and we discuss the contribution of emerging therapies that shed some light on the pathogenesis of the disease.

Environmental triggers for connective tissue disease: the case of COVID-19 associated with dermatomyositis-specific autoantibodies

PURPOSE OF REVIEW

The aim of the present review is to analyze the link between autoimmune diseases and environmental factors, in particular severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (COVID-19) as it shares numerous features with the interstitial lung disease associated with connective tissue diseases positive for rare autoantibodies directed at highly specific autoantigens (i.e., MDA5 and RIG1) among the intracellular sensors of SARS-CoV-2 in the innate response against viruses.

RECENT FINDINGS

As shown in recent publications and in our original data, specific autoantibodies may be functionally relevant to COVID-19 infection. We evaluated sera from 35 hospitalized patients with COVID-19 to identify antinuclear antibodies and autoantibodies directed against specific antigenic targets, and we identified anti-nuclear antibodies (ANA) in 20/35 of patients with COVID-19 (57%), in patients with need for supplemental oxygen (90% vs. 20% in ANA-negative cases; P < 0.0001). In 7/35 COVID-19 sera, we detected anti-MJ/NXP2 (n = 3), anti-RIG1 (n = 2), anti-Scl-70/TOPO1 (n = 1), and anti-MDA5 (n = 1), overall associated with a significantly worse pulmonary involvement at lung computerized tomography scans. Eleven (31%) patients were positive for antibodies against the E2/E3 subunits of mitochondrial pyruvate dehydrogenase complex.

SUMMARY

Viral infections such as COVID-19 are associated with ANA and autoantibodies directed toward antiviral signaling antigens in particular in patients with worse pulmonary involvement.

Pharmacologic Treatment of Anti-MDA5 Rapidly Progressive Interstitial Lung Disease

Purpose of the Review

Idiopathic inflammatory myopathies are a heterogeneous group of autoimmune disorders. The presence of different autoantibodies allows clinicians to define distinct phenotypes. Antibodies against the melanoma differentiation-associated protein 5 gene, also called anti-MDA5 antibodies, are associated with a characteristic phenotype, the clinically amyopathic dermatomyositis with rapidly progressive interstitial lung disease. This review aims to analyze the different pharmacological options for the treatment of rapidly progressive interstitial lung disease in patients with anti-MDA5 antibodies.

Recent Findings

Evidence-based therapeutic recommendations suggest that the best initial approach to treat these patients is an early combination of immunosuppressive drugs including either glucocorticoids and calcineurin inhibitors or a triple therapy adding intravenous cyclophosphamide. Tofacitinib, a Janus kinase inhibitor, could be useful according to recent reports. High ferritin plasma levels, generalized worsening of pulmonary infiltrates, and ground-glass opacities should be considered predictive factors of a bad outcome. In this scenario, clinicians should consider rescue therapies such as therapeutic plasma exchange, polymyxin-B hemoperfusion, veno-venous extracorporeal membrane oxygenation, or even lung transplantation.

Summary

Combined immunosuppressive treatment should be considered the first-line therapy for patients with anti-MDA5 rapidly progressive interstitial lung disease. Aggressive rescue therapies may be useful in refractory patients.

Prognostic values of anti-Ro52 antibodies in anti-MDA5-positive clinically amyopathic dermatomyositis associated with interstitial lung disease

OBJECTIVE

Anti-Ro52 antibody often co-occurs with anti-Jo1 antibody in antisynthetase syndrome and their co-occurrence correlates with a more aggressive clinical phenotype and poorer prognosis. The strong association of anti-Ro52 antibody with anti-melanoma differentiation-associated protein-5 (anti-MDA5) antibody has been indicated in juvenile myositis. The aim of this study was to assess the clinical significance of anti-Ro52 antibody in a cohort of adult patients with anti-MDA5-positive clinically amyopathic dermatomyositis with interstitial lung disease (CADM-ILD).

METHODS

We assessed a cohort of 83 consecutive patients with anti-MDA5-positive CADM-ILD. Anti-MDA5 antibodies and anti-Ro52 antibodies were detected in immunoblotting and semi-quantitatively analysed by densitometry. Clinical features and the 24 month survival were compared between anti-MDA5-positive patients with and without anti-Ro52 antibodies.

RESULTS

Anti-Ro52 antibodies were found in 74.7% of anti-MDA5-positive CADM-ILD patients and were associated with an increased frequency of rapidly progressive interstitial lung disease (RP-ILD; 54.8% vs 23.8%; P = 0.014) and cutaneous ulcerations (27.4% vs 4.8%; P = 0.033). The cumulative 24 month survival rate tended to be lower in patients with anti-Ro52 antibodies than patients without (59.9% vs 85.7%; P = 0.051). The combination of anti-Ro52 antibody status and anti-MDA5 antibody levels further stratified patients' survival rates, showing that the survival rate of patients who were dual positive for anti-MDA5 antibody and anti-Ro52 antibody was significantly lower than patients with mild positive anti-MDA5 antibody alone (59.9% vs 100%; P = 0.019).

CONCLUSION

Anti-Ro52 antibody is highly prevalent in anti-MDA5-positive CADM-ILD patients and their coexistence correlates with a subgroup of patients with more aggressive phenotypes. The combination of anti-MDA5 antibody levels and anti-Ro52 antibody status could help to predict patients' prognosis and guide risk-based therapy.

Early intervention of plasma exchange combined with intensive immunosuppressive treatment for anti-MDA-5 antibody-positive rapidly progressive interstitial pneumonia: Two case reports

Background

Anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) has to be reported to often cause rapidly progressive interstitial lung disease (RP-ILD) especially in East Asian countries. Even with the recommended rapid administration of immunosuppressive agents with high-dose corticosteroids, intravenous pulse cyclophosphamide, and calcineurin inhibitors, the prognosis of anti-MDA5 Ab-related RP-ILD is poor. Plasma exchange (PE) has been reported to be effective for steroid-refractory RP-ILD with anti-MDA5 Ab. However, the timing, frequency, and interval of PE for the treatment of RP-ILD with anti-MDA5 Ab have not yet been established.

Case presentation

We report two cases of RP-ILD with anti-MDA5 Ab treated by early intervention of PE combined with immunosuppressive treatment. Blood biomarkers including titers of anti-MDA5 Ab, serum KL-6 and ferritin were promptly decreased after each session of PE. Clinical symptoms, oxygenation and chest computed tomography abnormalities were completely improved after immunosuppressive treatment with PE.

Conclusion

Early intervention of PE combined with immunosuppressive treatment may prevent the development to lethal severe respiratory failure in RP-ILD with anti-MDA5 Ab.

Role of autoantibodies in the diagnosis and prognosis of interstitial lung disease in autoimmune rheumatic disorders

Interstitial lung disease (ILD) has been recognized as a frequent manifestation associated with a substantial morbidity and mortality burden in patients with autoimmune rheumatic disorders. Serum autoantibodies are considered good biomarkers for identifying several subsets or specific phenotypes of ILD involvement in these patients. This review features the role of several autoantibodies as a diagnostic and prognostic biomarker linked to the presence ILD and specific ILD phenotypes in autoimmune rheumatic disorders. The case of the diverse antisynthetase antibodies in the antisynthease syndrome or the anti-melanoma differentiation-associated 5 protein (MDA5) antibodies as a marker of a severe condition such as rapidly progressive ILD in patients with clinically amyopathic dermatomyositis are some of the associations herein reported in the group of myositis spectrum disorders. Specific autoantibodies such as the well-known anti-topoisomerase I (anti-Scl70) or the anti-Th/To, anti-U11/U12 ribonucleoprotein, and anti-eukaryotic initiation factor 2B (eIF2B) antibodies seems to be specifically linked to ILD in patients with systemic sclerosis. Overlap syndromes between systemic sclerosis and myositis, also have good ILD biomarkers, which are the anti-PM/Scl and anti-Ku autoantibodies. Lastly, other not so often reported disorders as being associated with ILD but recently most recognized as is the case of rheumatoid arthritis associated ILD or entities herein included in the miscellaneous disorders section, which include anti-neutrophil cytoplasmic antibody-associated interstitial lung disease, Sjögren's syndrome or the mixed connective tissue disease, are also discussed.

Myositis-Related Interstitial Lung Disease: A Respiratory Physician's Point of View

Idiopathic inflammatory myositis (IIM) is an umbrella term for diseases of unknown origin that cause muscle inflammation. Dermatomyositis and polymyositis are IIMs that commonly cause interstitial lung disease (ILD). When a patient presents with ILD, the evaluation of whether the case displays the characteristics of myositis should be determined by interview, physical examination, imaging findings, the measurement of myositis-related antibodies, and the determination of disease severity after diagnosis. Rapidly progressing anti-melanoma differentiation-associated gene 5 antibody-positive ILD may require rapid multi-drug therapy, while anti-aminoacyl tRNA synthetase (ARS) antibody-positive ILD can be treated with anti-inflammatory drugs. Importantly, however, anti-ARS antibody-positive ILD often recurs and sometimes develops into fibrosis. Early diagnosis is crucial for treatment, and we therefore need to clarify the features of myositis associated with ILD and suspect these pathologies early. This section reviews what clinicians need to look for and what findings are evaluated in patients when diagnosing myositis associated with ILD.

Disease characteristics and clinical outcomes of adults and children with anti-MDA-5 antibody-associated myositis: a prospective observational bicentric study

To study the demographic, clinical and serologic characteristics of anti-MDA5-positive DM from two geographically and ethnically disparate inception cohorts in India. To identify the clinical and serological parameters at inception that could predict mortality among these individuals. Individuals with anti-MDA5 antibody-positive DM diagnosed between 2017 and 2020 from two centres in India were prospectively followed up. The clinical and serological characteristics at baseline and the treatment outcome at follow-up were assessed for this study. Anti-MDA5 antibody was positive in 25 (7.5%) out of the 330 individuals with myositis. These 25 (21 adults, 4 juvenile) patients were followed up for a median duration of 14 months. Among adults, a majority had cutaneous manifestations 21 (84%) followed by, arthritis 17 (80%), and interstitial lung disease 12 (ILD, 57.1%). Four (19%) had rapidly progressive ILD (RP-ILD). Eight (38%) presented as clinically amyopathic DM. Among cutaneous manifestations, majority (62%) had classic features (gottron's papules/sign, heliotrope rash) while 8 (38%) had cutaneous ulceration and 2 each had periorbital edema and tendon rupture. Eight (38%) were positive for anti-Ro-52 antibody. Out of 21 adults, 8 (38%) succumbed to the diseases. RP-ILD (n = 4; 19%), ulcerative gottron's (n = 5) and anti-Ro-52 (n = 8) were significantly associated with mortality (p < 0.05). Upon binary logistic regression, positive anti-Ro-52 antibody predicted mortality [HR 17.3 (95%CI 1.4-210, p = 0.025)]. All juvenile anti-MDA5-positive DMs had classic cutaneous features with 2 of them having ulcerative gottron's. None of the juvenile patients had ILD and everyone survived till the last follow-up. Indian adults with anti-MDA5 DM have high mortality. Rarer atypical features like tendon rupture or periorbital edema could assist in diagnosis. Ulcerative gottron's, positive anti-Ro 52 antibodies, and RP-ILD are valuable clinical-serological markers that portend poor prognosis.

Understanding and managing anti-MDA 5 dermatomyositis, including potential COVID-19 mimicry

Anti-Melanoma Differentiation-Associated gene 5 (MDA-5) Dermatomyositis (MDA5, DM) is a recently identified subtype of myositis characteristically associated with Rapidly Progressive Interstitial Lung Disease (RP-ILD) and unique cutaneous features. We reviewed PubMed, SCOPUS and Web of Science databases and selected 87 relevant articles after screening 1485 search results, aiming to gain a better understanding of the pathophysiology, clinical features, diagnosis, and treatment approaches of anti-MDA-5 DM described in the literature. The etiopathogenesis is speculatively linked to an unidentified viral trigger on the background of genetic predisposition culminating in an acquired type I interferonopathy. The clinical phenotype is highly varied in different ethnicities, with new clinical features having been recently described, expanding the spectrum of cases that should raise the suspicion of anti-MDA-5 DM. Unfortunately, the diagnosis is frequently missed despite excessive mortality, calling for wider awareness of suspect symptoms. RP ILD is the major determinant of survival, treatment being largely based on observational studies with recent insights into aggressive combined immunosuppression at the outset.

Dermatomyositis autoantibodies: how can we maximize utility?

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

Recurrence in long-term survivor of anti-MDA5 antibody-positive clinically amyopathic dermatomyositis: case series and literature review

Anti-MDA5 antibody-positive clinically amyopathic dermatomyositis (CADM) is often complicated by rapidly progressive interstitial lung disease and is associated with poor prognosis. However, even though recurrence is reported to be infrequent if successful medical treatment is administered, the long-term prognosis remains unclear. In this case report, we examined the clinical features and treatment details of three patients with anti-MDA5 antibody-positive CADM with multiple recurrences during long-term survival at Juntendo University Urayasu Hospital. Of the three patients, two failed to convert to an anti-MDA5 antibody-negative status, and one patient died. One of the remaining patients experienced two relapses but eventually tested negative for anti-MDA5 antibodies and showed a relatively stable clinical course. Although cases of recurring anti-MDA5 antibody-positive CADM rarely occur, they may occasionally be fatal. The prognosis for anti-MDA5 antibody-positive CADM has improved over time owing to its establishment as a disease. However, further information and research is necessary to ascertain its long-term prognosis.

Anti-MDA5 juvenile idiopathic inflammatory myopathy: a specific subgroup defined by differentially enhanced interferon-α signalling

OBJECTIVES

JDM and juvenile overlap myositis represent heterogeneous subtypes of juvenile idiopathic inflammatory myopathy (JIIM). Chronic evolution can occur in up to 60% of cases, and morbidity/mortality is substantial. We aimed to describe the clinical, biological, histological and type I IFN status in JIIM associated with anti-melanoma differentiation-associated protein 5 (anti-MDA5) autoantibodies at presentation (group 1) in comparison with other JIIM (group 2).

METHODS

This was a retrospective and prospective study of patients with JIIM ascertained from three French paediatric rheumatology reference centres between 2013 and 2019. Muscle biopsies were reviewed. Type I interferon pathway activity was assessed by dosage of IFNα serum protein and the expression of IFN-stimulated genes.

RESULTS

Sixty-four patients were included, 13 in group 1 (54% JDM and 46% juvenile overlap myositis) and 51 in group 2 (76% JDM and 24% juvenile overlap myositis). Group 1 patients demonstrated more arthritis, skin ulcerations, lupus features and interstitial lung disease, and a milder muscular involvement. Serum IFNα levels were higher in group 1 than 2, and decreased after treatment or improvement in both groups. Outcome was similar in both groups. Unconventional treatment (more than two lines) was required in order to achieve remission, especially when skin ulceration was reported.

CONCLUSION

This study indicates a higher frequency of arthritis, skin ulcerations and interstitial lung disease, but milder muscular involvement, in JIIM with positive anti-MDA5 autoantibodies compared with other JIIM. Our data support an important role of systemic IFNα in disease pathology, particularly in the anti-MDA5 auto-antibody-positive subgroup. In severe and refractory forms of JIIM, IFNα may represent a therapeutic target.

Interstitial Lung Disease in Anti-MDA5 Positive Dermatomyositis

Anti-melanoma differentiation-associated gene 5-positive dermatomyositis (MDA5⁺ DM) is a rare autoimmune disease predominantly reported in East Asia. MDA5⁺ DM is an intractable disease with impressively high mortality due to rapid-progressive interstitial lung disease (RPILD). Other typical clinical manifestations comprise DM-specific rash (Gottron's papules, heliotrope rash) and amyopathic/hypomyopathic muscle involvement. Multiple prognostic factors have been identified. Baseline forced vital capacity (FVC) %-based staging could serve as a simplified risk stratification system. Serum biomarkers including MDA5 Ab titers, ferritin, KL-6 levels, and CD4⁺CXCR4⁺ T cell percentage could provide additional surrogate value of ILD severity and treatment response, as well as potential predictive value for survival. Spontaneous pneumomediastinum (PNM), ground-glass opacity (GGO), and consolidation were demonstrated to be the most significant features in pulmonary high-resolution computed tomography (HRCT) findings of MDA5⁺ DM-ILD. The semi-quantitative assessment of lesions in HRCT has also been demonstrated relevant to the outcome. The current treatment of this disease is still largely empirical. Immunosuppressive treatments, i.e., "triple therapy" (combination of high-dose glucocorticoids, tacrolimus, and intravenous cyclophosphamide) and JAK inhibitor-based therapy, are the mainstream regimens for MDA5⁺ DM-ILD, supported by the recently published trials. However, more efficacious regimen with favorable safety profile and high-level evidence is still urgently demanded for patients with MDA5⁺ DM-ILD, especially those at advanced-stage. We will summarize the terminology, etiology and pathogenesis, clinical features and outcome, prognostic factors, and treatment of MDA5⁺ DM-ILD in this review.

Fatal outcome of anti-MDA5 juvenile dermatomyositis in a paediatric COVID-19 patient: a case report

Anti-melanoma differentiation-associated gene 5 juvenile dermatomyositis (anti-MDA5 JDM) is associated with high risk of developing rapidly progressive interstitial lung disease (RP-ILD). Here we report an 11-year-old girl with anti-MDA5 JDM and RP-ILD which led to a fatal outcome, further aggravated by SARS-CoV-2 infection. She was referred to our hospital after being diagnosed with anti-MDA5 JDM and respiratory failure due to RP-ILD. On admission, fibrobronchoscopy with bronchoalveolar lavage (BAL) revealed Pneumocystis jirovecii infection so treatment with intravenous trimethoprim-sulfamethoxazole was initiated. Due to RP-ILD worsening, immunosuppressive therapy was intensified using methylprednisolone pulses, cyclophosphamide, tofacitinib and intravenous immunoglobulin without response. She developed severe hypoxemic respiratory failure, pneumomediastinum and pneumothorax, further complicated with severe RP-ILD and cervical subcutaneous emphysema. Three real-time RT-PCR for SARS-CoV-2 were made with a negative result. In addition, she was complicated with a secondary hemophagocytic lymphohistiocytosis and a fourth real-time PCR for SARS-CoV-2 performed in BAS sample was positive. Despite aggressive treatment of RP-ILD due to anti-MDA5 JDM, there was no improvement of respiratory failure in the following days and patient developed refractory septic shock and died. Anti-MDA5 JDM patients with RP-ILD have a poor prognosis with a high mortality rate. For this reason, intensive immunosuppressive therapy is essential including the use of promising drugs such as tofacitinib. COVID-19 in children with underlying health conditions like anti-MDA5 JDM may still be at risk for disease and severe complications.

Rituximab in Antimelanoma Differentiation-Associated Protein-5 Dermatomyositis with Interstitial Lung Disease

In this paper, we report a challenging case of a middle-age woman who developed antimelanoma differentiation-associated protein-5 dermatomyositis (anti-MDA5 DM) with interstitial lung disease (ILD) and was successfully treated with rituximab (RTX), after failure of a first-line therapy.

Interstitial pneumonia with autoimmune features in a patient with melanoma differentiation-associated gene 5 (MDA5) antibody

Melanoma differentiation-associated gene 5 (MDA5) antibody, also known as anti-CADM140 antibody is recognised to be associated with rapidly progressive interstitial lung disease, which can be fatal within 3 months. It is also known to be associated with amyopathic dermatomyositis. We report a case of MDA5 antibody-associated interstitial pneumonia with autoimmune features, without cutaneous features of dermatomyositis, in a Sudanese patient with dual positive antibodies to Ro52. The patient notably had several features associated with poor prognosis, including age, high serum ferritin level, anti-Ro52 antibodies and progressive lung infiltrates during treatment.

Early initiation of plasma exchange therapy for a patient with anti-MDA5 autoantibody-positive dermatomyositis developing rapidly progressive interstitial lung disease

Dermatomyositis (DM) is a categorised as one of idiopathic inflammatory myopathy (IIM) indicated by symmetrical proximal muscle weakness as well as characteristic cutaneous manifestations typical of DM. Clinically amyopathic dermatomyositis (CADM), a subtype of DM, shows only the skin involvement without any clinical signs of myositis. This condition is often associated with fatal anti-MDA5 antibody-positive rapidly progressive interstitial lung disease (RP-ILD), especially in Eastern Asian populations. Here, we report a CADM patient with anti-MDA5 antibody-positive RP-ILD whom we successfully treated by early initiation of plasma exchange (PE) together with multiple immunosuppressive therapies. In this patient, initial treatment with high-dose prednisolone (PSL), tacrolimus and intermittent intravenous cyclophosphamide had resulted in no obvious improvement in the respiratory condition. Therefore, soon after the first evaluation, we initiated PE therapy in addition to these multiple immunosuppressive therapies. Although the patient had pneumomediastinum, cytomegalovirus and fungal infections over the clinical course, RP-ILD did gradually improved and the anti-MDA5 titre decreased down to within the normal range paralleled by improvement in the patient's respiratory condition.

Plasma homocysteine levels are positively associated with interstitial lung disease in dermatomyositis patients with anti-aminoacyl-tRNA synthetase antibody

Homocysteine is a sulfhydryl-containing amino acid that is derived from dietary methionine, and there has been increasing evidence that elevated plasma homocysteine levels are associated with increased risk of central and peripheral vascular disorders, including carotid, coronary and peripheral arterial diseases, and Raynaud's phenomenon. Recently, associations of plasma homocysteine levels with autoimmune diseases such as systemic lupus erythematodes and systemic sclerosis have been reported. However, no study analyzed the association between plasma homocysteine levels and dermatomyositis (DM). The objective of this study was to examine plasma homocysteine levels and their clinical associations in patients with DM. Plasma homocysteine levels in 28 Japanese patients with DM and 22 healthy controls were examined. We found that the plasma homocysteine levels in DM patients were significantly higher than those in healthy individuals (15.8 ± 1.1 vs 8.5 ± 0.5 µmol/L, P < 0.01). Presence of mechanic's hand, complication of interstitial lung disease (ILD), high serum Krebs von den Lungen-6 (KL-6), surfactant protein-D and creatine kinase levels, and anti-aminoacyl-tRNA synthetase (ARS) antibody (Ab) positivity were significantly more prevalent among DM patients with elevated plasma homocysteine levels. The plasma homocysteine levels in DM patients with mechanic's hand, ILD and anti-ARS Ab were significantly higher than those in DM without those features. Furthermore, the plasma homocysteine levels were positively correlated with serum KL-6 levels. These results suggest that the pathogenesis of elevated plasma homocysteine levels may be associated with ILD in DM patients, especially with anti-ARS Ab, and further examination is required.

Successful treatment of anti-MDA5 antibody-positive refractory interstitial lung disease with plasma exchange therapy

OBJECTIVES

We examined the effectiveness of plasma exchange (PE) therapy to reduce the mortality of rapidly progressive interstitial lung disease (RP-ILD) in patients positive for anti-melanoma differentiation-associated gene 5 (MDA5) antibodies.

METHODS

Among 142 patients newly diagnosed with PM/DM or clinically amyopathic DM from 2008 to 2019 at our hospital, 10 were diagnosed with refractory RP-ILD and were positive for anti-MDA5 antibodies. PE was used as an adjunct to standard therapy and consisted of fresh frozen plasma as replacement solution. The primary outcome was non-disease-specific mortality.

RESULTS

Anti-MDA5 antibodies were detected in 28 patients, of whom 21 were diagnosed with RP-ILD and 10 were refractory to intensive immunosuppressive therapy. Six patients received PE (PE group) and four did not (non-PE group). The 1-year survival rate of the PE group was higher than that of the non-PE group (100% and 25%, respectively, P = 0.033). Regarding adverse events associated with PE, two patients had anaphylactic shock, one had high fever due to fresh frozen plasma allergy and one had a catheter infection. All adverse events resolved with appropriate treatment.

CONCLUSION

We evaluated the association between 1-year survival rate and PE for refractory RP-ILD in patients positive for anti-MDA5 antibodies. Intensive immunosuppressive therapy improved the survival rate in RP-ILD patients with anti-MDA5 antibodies, but 20-30% of cases were still fatal. PE could be administered to patients with active infectious disease who were immunocompromised by intensive immunosuppressive therapy. PE may be considered in refractory RP-ILD patients positive for anti-MDA5 antibodies.

Study on the differentially expressed genes and signaling pathways in dermatomyositis using integrated bioinformatics method

Dermatomyositis is a common connective tissue disease. The occurrence and development of dermatomyositis is a result of multiple factors, but its exact pathogenesis has not been fully elucidated. Here, we used biological information method to explore and predict the major disease related genes of dermatomyositis and to find the underlying pathogenic molecular mechanism.The gene expression data of GDS1956, GDS2153, GDS2855, and GDS3417 including 94 specimens, 66 cases of dermatomyositis specimens and 28 cases of normal specimens, were obtained from the Gene Expression Omnibus database. The 4 microarray gene data groups were combined to get differentially expressed genes (DEGs). The gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments of DEGs were operated by the database for annotation, visualization and integrated discovery and KEGG orthology based annotation system databases, separately. The protein-protein interaction networks of the DEGs were built from the STRING website. A total of 4097 DEGs were extracted from the 4 Gene Expression Omnibus datasets, of which 2213 genes were upregulated, and 1884 genes were downregulated. Gene ontology analysis indicated that the biological functions of DEGs focused primarily on response to virus, type I interferon signaling pathway and negative regulation of viral genome replication. The main cellular components include extracellular space, cytoplasm, and blood microparticle. The molecular functions include protein binding, double-stranded RNA binding and MHC class I protein binding. KEGG pathway analysis showed that these DEGs were mainly involved in the toll-like receptor signaling pathway, cytosolic DNA-sensing pathway, RIG-I-like receptor signaling pathway, complement and coagulation cascades, arginine and proline metabolism, phagosome signaling pathway. The following 13 closely related genes, XAF1, NT5E, UGCG, GBP2, TLR3, DDX58, STAT1, GBP1, PLSCR1, OAS3, SP100, IGK, and RSAD2, were key nodes from the protein-protein interaction network.This research suggests that exploring for DEGs and pathways in dermatomyositis using integrated bioinformatics methods could help us realize the molecular mechanism underlying the development of dermatomyositis, be of actual implication for the early detection and prophylaxis of dermatomyositis and afford reliable goals for the curing of dermatomyositis.

Therapeutic plasma exchange for clinically amyopathic dermatomyositis (CADM) associated with rapidly progressive interstitial pneumonia

BACKGROUND

Patients with clinically amyopathic dermatomyositis (CADM) with anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) frequently develop rapidly progressive interstitial pneumonia (RPIP), often with fatal outcomes. Therapeutic plasma exchange (TPE) has been reported as effective against CADM-RPIP refractory to conventional immunosuppressive therapy. However, the detailed mechanisms by which TPE improves disease activity of CADM-RPIP remain unclear.

AIM

To elucidate the clinical and demographic characteristics of patients with anti-MDA5 Ab-positive CADM-RPIP treated with TPE and to analyze changes in laboratory findings before, during, and after TPE.

MATERIALS & METHODS

Patients hospitalized for CADM-RPIP and treated with TPE in 2017 and 2018 were analyzed retrospectively.

RESULTS

Three patients were successfully treated with TPE, with good tolerance. Anti-MDA5 Ab titers decreased significantly over the course of TPE.

CONCLUSION

We emphasize that TPE could represent an effective treatment option for CADM-RPIP refractory to traditional therapy. Removal of anti-MDA5 Ab and other pathogenic factors may facilitate favorable outcomes.

Demographic and clinical characteristics of cytomegalovirus reactivation in dermatomyositis

Dermatomyositis (DM) patients are known to have various infectious complications, such as cytomegalovirus (CMV) reactivation, due to immune dysfunction caused by DM itself and immunosuppressants used for treatment. Although CMV reactivation has been known to be a major cause of mortality in immunocompromised hosts, there has not been sufficient study of CMV reactivation in DM patients. The objective of this study was to examine the frequency of CMV reactivation in DM patients and to investigate risk factors potentially associated with development of CMV reactivation. We analyzed 52 Japanese DM patients, and CMV reactivation was observed in 21 (40.4%). The mean duration from the initiation of prednisolone (PSL) to the diagnosis of CMV reactivation was 6.1 ± 0.5 weeks. The total amount of oral PSL before the diagnosis of CMV reactivation was 2000.3 ± 169.3 mg. Using a univariate analysis, we found that the prevalence of interstitial lung disease and the frequency of diabetes mellitus complications in DM patients with CMV reactivation was significantly higher than that in DM patients without CMV. We identified that low lymphocytes (<900/μL) in DM patients was significantly associated with developing CMV reactivation. The use of immunosuppressants, including tacrolimus, cyclosporin and/or i.v. cyclophosphamide, was significantly associated with CMV reactivation in DM patients. Using a multivariate analysis, low lymphocytes at the time of DM diagnosis was found to be a risk factor for CMV reactivation. In addition, there was a tendency for diabetes mellitus to be a risk factor for CMV reactivation in DM patients. There was no difference in the prognosis for those with or without CMV reactivation in this study. These results suggest that in the DM patients with risk factors such as low lymphocytes and diabetes mellitus complications, regularly monitoring CMV reactivation and adequate treatment with antiviral agents may be necessary to prevent a poor prognosis.

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

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

Insights into pathogenesis and clinical implications in myositis-associated interstitial lung diseases

PURPOSE OF REVIEW

Interstitial lung diseases (ILDs) have been reported to be associated with myositis (including polymyositis and dermatomyositis). These myositis-associated ILDs carry significant morbidity and mortality. This review summarizes recent findings on myositis-associated ILD with a focus on pathogenesis and emerging treatment.

RECENT FINDINGS

Recent advances in genetics have revealed 22 myositis-associated genome-wide loci, which were significantly enriched in regulatory regions in immune cells. An analysis of such disease-associated loci elucidated potential drug targets (e.g., TYK2 targeted by tofacitinib). In another study, an intronic variant in WDFY4 in association with clinically amyopathic dermatomyositis (CADM) had an effect for higher expression of a truncated WDFY4 isoform. Truncated WDFY4 markedly enhanced the MDA5-mediated NF-κB activation and cell apoptosis, indicating the dysregulated WDFY4-MDA5 pathway as a novel pathogenesis of CADM. As a novel strategy, tofacitinib treatment showed a promising improvement in survival and clinical features of CADM-associated ILD.

SUMMARY

The genetic differences in the myositis-susceptible loci may explain the heterogeneous phenotypes and treatment responses in myositis-associated ILD. The understanding of pathogenesis with the genetic background as well as autoantibodies will enable the practice of personalized treatment in the management of the disease.

Recommendations for the treatment of anti-melanoma differentiation-associated gene 5-positive dermatomyositis-associated rapidly progressive interstitial lung disease

OBJECTIVES

The study aimed to develop evidence-based recommendations for the treatment of rapidly progressive interstitial lung disease (RPILD) associated with the anti-Melanoma Differentiation-Associated Gene 5-positive dermatomyositis (DM) syndrome.

METHODS

The task force comprised an expert panel of specialists in rheumatology, intensive care medicine, pulmonology, immunology, and internal medicine. The study was carried out in two phases: identifying key areas in the management of DM-RPILD syndrome and developing a set of recommendations based on a review of the available scientific evidence. Four specific questions focused on different treatment options were identified. Relevant publications in English, Spanish or French up to April 2018 were searched systematically for each topic using PubMed (MEDLINE), EMBASE, and Cochrane Library (Wiley Online). The experts used evidence obtained from these studies to develop recommendations.

RESULTS

A total of 134 studies met eligibility criteria and formed the evidentiary basis for the recommendations regarding immunosuppressive therapy and complementary treatments. Overall, there was general agreement on the initial use of combined immunosuppressive therapy. Combination of high-dose glucocorticoids and calcineurin antagonists with or without cyclophosphamide is the first choice. In the case of calcineurin antagonist contraindication or treatment failure, switching or adding other immunosuppressants may be individualized. Plasmapheresis, polymyxin B hemoperfusion and/or intravenous immunoglobulins may be used as rescue options. ECMO should be considered in life-threatening situations while waiting for a clinical response or as a bridge to lung transplant.

CONCLUSIONS

Thirteen recommendations regarding the treatment of the anti-MDA5 positive DM-RPILD were developed using research-based evidence and expert opinion.

Mortality Risk Prediction in Amyopathic Dermatomyositis Associated With Interstitial Lung Disease: The FLAIR Model

BACKGROUND

The prognosis of amyopathic dermatomyositis (ADM)-associated interstitial lung disease (ILD) is poor. A mortality risk score model is needed to predict survival in patients with ADM-ILD and to guide clinical treatment.

RESEARCH QUESTION

How to identify patients with ADM-ILD who are at high risk and to predict patient outcome based on a risk stratification model?

STUDY DESIGN AND METHODS

We evaluated 207 patients with ADM-ILD in this prospective inception study. We used a multivariable Cox proportional hazards model to identify the independent prognostic risk factors and created a risk score model according to patient data from January 2012 to December 2016. We used the index of prediction accuracy that uses the Brier score to reflect both discrimination and calibration of the model. The model was validated in an independent group of patients from January 2017 to June 2018.

RESULTS

We developed a combined risk score, the FLAIR score, that included the following values and scores: ferritin (<636 ng/mL, 0; ≥636 ng/mL, 2), lactate dehydrogenase (<355 U/L, 0; ≥355 U/L, 2), antimelanoma differentiation-associated gene 5 antibody (negative, 0; +, 2; ++, 3; +++, 4), high-resolution CT imaging score (<133, 0; ≥133, 3), and rapidly progressive ILD (RPILD) (non-RPILD, 0; RPILD, 2). We divided patients into three risk groups according to the FLAIR score: low, 0 to 4; medium, 5 to 9; and high, 10 to 13. In both discovery and validation cohorts, high-risk patients had significantly higher mortality rates than low- and medium-risk patients (P < .001).

INTERPRETATION

The FLAIR risk score model could help to predict survival in patients with ADM-ILD and to guide further clinical research on risk-based treatment.

Interstitial Lung Disease in Polymyositis and Dermatomyositis

The idiopathic inflammatory myopathies (IIMs), including polymyositis (PM) and dermatomyositis (DM), are autoimmune connective tissue diseases with variable degrees of muscle inflammation and systemic involvement. Interstitial lung disease (ILD) is a common complication of the IIMs and is associated with increased mortality. Many patients with PM/DM have myositis-specific and myositis-associated antibodies (MSA/MAAs) that result in distinct clinical phenotypes. Among these MSAs, anti-aminoacyl-tRNA antibodies and anti-melanoma differentiation factor 5 antibodies have high rates of ILD. Corticosteroids are the mainstay of treatment, although the addition of other immunosuppressive therapy is typically necessary to achieve disease control.

Interstitial Lung Disease-Complicated Anti-MDA5 Antibody in Clinically Amyopathic Dermatomyositis Patients: Report of Two Cases With Distinct Clinical Features

Two patients presented simultaneously to our hospital with distinct clinical features associated with the presence of anti-MDA5 antibodies: the first one was admitted for a skin rash resembling to a toxic epidermal necrosis (Lyell syndrome) and the second one presented with pulmonary manifestations attributed to a diffuse fibrosing interstitial pneumonitis on chest CT-scan. In addition to the skin lesions involving 40% of the body surface area, the first patient developed a rapid diffuse interstitial pneumonitis with respiratory distress justifying the initiation of a systemic immunosuppressive treatment. However, she died 3 weeks after her admission from mesenteric thrombosis associated with septic shock. The second patient respiratory condition worsened despite an intensive immunosuppressive treatment with high doses of intravenous methylprednisolone and cyclophosphamide and plasmapheresis, and required lung transplantation. Anti-MDA5 antibody titer declined and disappeared on anti-rejection treatment. These two cases underline the diagnostic conundrum and the therapeutic difficulties in patients with anti-MDA5 antibodies and clinically amyopathic dermatomyositis (CADM) or interstitial lung disease (ILD), who may undergo rapidly-progressive and fatal outcome. Presence of anti-MDA5 antibodies should always be suspected when confronted to CADM patients with cutaneous ulcerations or ILD to allow a rapid and adapted treatment initiation.

Acute lung injury after plasma exchange in a patient with anti-MDA5 antibody-positive, rapidly progressive, interstitial lung disease：A case report

The presence of anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) is closely associated with rapidly progressive interstitial lung disease (RP-ILD) in patients with clinically amyopathic dermatomyositis. Despite intensive immunosuppressive therapies, some of these patients still have a poor prognosis with few treatment options. Although removal of pathogenic autoantibodies and cytokines by plasma exchange (PE) could be a treatment option, its safety and efficacy have never been determined. We report a patient with anti-MDA5 Ab-positive RP-ILD who was refractory to intensive therapies including steroids, cyclosporine, and intravenous cyclophosphamide, and then treated by PE to prevent the progression of RP-ILD. Shortly after the initiation of PE therapy, however, his respiratory condition suddenly deteriorated due to acute pulmonary edema and the patient died on the following day. Transfusion-related acute lung injury (TRALI) would be the most likely cause of the acute pulmonary edema because there was no sign of circulatory overload. To the best of our knowledge, this is the first report showing a critical adverse event associated with PE therapy for these patients. This case supports the idea that the presence of ILD could increase a risk for TRALI and therefore we should carefully evaluate the eligibility for PE therapy of anti-MDA5 Ab-positive RP-ILD patients given the risk of acute lung injury. Further studies collecting more clinical data are necessary to assess the efficacy, safety, and risk factors of PE therapy for these patients.

Multicenter Prospective Study of the Efficacy and Safety of Combined Immunosuppressive Therapy With High-Dose Glucocorticoid, Tacrolimus, and Cyclophosphamide in Interstitial Lung Diseases Accompanied by Anti-Melanoma Differentiation-Associated Gene 5-Positive Dermatomyositis

OBJECTIVE

Interstitial lung disease (ILD) accompanied by anti-melanoma differentiation-associated gene 5 (anti-MDA-5)-positive dermatomyositis (DM) is often rapidly progressive and associated with poor prognosis. Because there is no established treatment, we undertook this study to prospectively evaluate the efficacy and safety of a combined immunosuppressive regimen for anti-MDA-5-positive DM patients with ILD.

METHODS

Adult Japanese patients with new-onset anti-MDA-5-positive DM with ILD (n = 29) were enrolled at multiple study centers from 2014 to 2017. They were treated with a regimen of high-dose glucocorticoids (GCs), tacrolimus, and intravenous cyclophosphamide (IV CYC). Plasmapheresis was used if a patient's condition worsened after the regimen started. The primary end point was 6-month survival, which was compared between this group of patients and a historical control group (n = 15) consisting of anti-MDA-5-positive DM patients with ILD who received step-up treatment (high-dose GC and stepwise addition of immunosuppressant). Secondary end points were 12-month survival rate, adverse events, and changes in laboratory data.

RESULTS

The combined immunosuppressive regimen group showed significantly higher 6-month survival rates than the step-up treatment group (89% versus 33%; P < 0.0001). Over a period of 52 weeks, improvements in anti-MDA-5 titers, serum ferritin levels, vital capacity, and chest high-resolution computed tomography scores were observed. The combined immunosuppressive regimen group received IV CYC nearly 20 days earlier with shorter intervals and tended to receive plasmapheresis more often than patients undergoing step-up treatment. Cytomegalovirus reactivation was frequently observed over 52 weeks.

CONCLUSION

A combined immunosuppressive regimen is effective for anti-MDA-5-positive DM patients with ILD. Plasmapheresis can be used for additional effect in intractable disease. Patients should be carefully monitored for opportunistic infections during treatment.

Elevated serum B-cell activating factor levels in patients with dermatomyositis: Association with interstitial lung disease

Patients with dermatomyositis (DM) frequently have myositis-specific autoantibodies (MSA), which are closely associated with different clinical features. Patients with anti-aminoacyl-tRNA synthetase antibody (ARS-Ab) and anti-melanoma differentiation-associated gene 5 (MDA5)-Ab often have interstitial lung disease (ILD). Recently, anti-MDA5-Ab levels have been shown to correlate with disease activity in DM patients. Thus, B cells that are stimulated by excess B-cell activating factor (BAFF) play an important role in the pathogenesis of DM through auto-Ab production. In this study, we investigated the role of BAFF in DM patients. We measured the serum BAFF levels in 56 adult DM patients (14 with anti-ARS-Ab, 18 with anti-MDA5-Ab, seven with anti-Mi-2-Ab and 17 with anti-transcriptional intermediary factor-1γ-Ab) . For a longitudinal study, 130 serum specimens from 10 DM patients with anti-MDA5-Ab were analyzed. Serum BAFF levels were significantly higher in DM patients than in healthy controls. DM patients with elevated serum BAFF levels more frequently had ILD. In subgroup analysis, DM patients with anti-ARS-Ab and DM patients with anti-MDA5-Ab exhibited increased BAFF levels compared with controls, while DM patients with other MSA showed BAFF levels comparable with controls. In the longitudinal study, serum BAFF levels in DM patients with anti-MDA5-Ab were decreased after immunosuppressive therapy along with serum levels of anti-MDA5-Ab and ferritin, which are biomarkers of disease activity. These results suggest that BAFF plays an important role in the pathogenesis of ILD in DM patients with anti-ARS and anti-MDA5-Ab. Furthermore, serum BAFF level is associated with disease activity in DM patients with anti-MDA5-Ab.

Clinical features of patients with anti-melanoma differentiation-associated gene-5 antibody-positive dermatomyositis complicated by spontaneous pneumomediastinum

BACKGROUND

Dermatomyositis (DM) with autoantibody against melanoma differentiation-associated gene-5 (MDA5) is characterized by elevated risk of rapidly progressive interstitial lung disease (RP-ILD) with a potentially fatal course. Pneumomediastinum (PNM) is a common pulmonary manifestation which accompanies ILD. However, the clinical features of the patients with anti-MDA5 antibody-positive DM who develop PNM remain unclear.

METHODS

We retrospectively examined 31 patients with DM having anti-MDA5 antibody and compared the clinical features between patients with PNM (PMN(+)) (n = 11) and those without (PNM(-) (n = 20). In addition, we evaluated the treatment-related prognoses in PNM(+) group.

RESULTS

CT score (total ground-glass opacity (GGO) score, P = 0.02; total fibrosis score, P = 0.02) before treatment, and mortality (P = 0.04) were significantly higher in PNM(+) group. The cumulative survival rate as assessed by Kaplan-Meier method was significantly lower for the PNM(+) group (P = 0.02). Among 11 PMN(+) patients, 9 patients (9/11, 81.8%) underwent intensive immunosuppression therapy for RP-ILD, and 5 patients (5/11, 45.5%) did not respond to it and died from the respiratory failure. At the time of diagnosis of PNM, nonsurvivors had worse liver function (ALT, P = 0.03; LDH, P = 0.01), worse respiratory status (A-aDO2, P = 0.01), and worse CT score (total GGO score, P < 0.01).

CONCLUSIONS

A subgroup of patients with DM having anti-MDA5 antibody complicated by PNM as well as RP-ILD did respond to intensive immunosuppression therapy. Initial aggressive immunosuppressive therapy should be considered for these patients.Key Points• This study clearly demonstrate the presence of PNM was associated with elevated risk of death due to respiratory failure from RP-ILD among patients with DM having circulating anti-MDA5-antibody.•This study demonstrate evaluation of CT image may be helpful to find patients with better response to the intense immunosuppression therapy for the patients with DM having circulating anti-MDA5-antibody and PNM.

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.

Lymphocyte-driven regional immunopathology in pneumonitis caused by impaired central immune tolerance

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a monogenic disorder caused by AIRE mutations, presents with several autoimmune diseases. Among these, endocrine organ failure is widely recognized, but the prevalence, immunopathogenesis, and treatment of non-endocrine manifestations such as pneumonitis remain poorly characterized. We enrolled 50 patients with APECED in a prospective observational study and comprehensively examined their clinical and radiographic findings, performed pulmonary function tests, and analyzed immunological characteristics in blood, bronchoalveolar lavage fluid, and endobronchial and lung biopsies. Pneumonitis was found in >40% of our patients, presented early in life, was misdiagnosed despite chronic respiratory symptoms and accompanying radiographic and pulmonary function abnormalities, and caused hypoxemic respiratory failure and death. Autoantibodies against BPIFB1 and KCNRG and the homozygous c.967_979del13 AIRE mutation are associated with pneumonitis development. APECED pneumonitis features compartmentalized immunopathology, with accumulation of activated neutrophils in the airways and lymphocytic infiltration in intraepithelial, submucosal, peribronchiolar, and interstitial areas. Beyond APECED, we extend these observations to lung disease seen in other conditions with secondary AIRE deficiency (thymoma and RAG deficiency). Aire-deficient mice had similar compartmentalized cellular immune responses in the airways and lung tissue, which was ameliorated by deficiency of T and B lymphocytes. Accordingly, T and B lymphocyte-directed immunomodulation controlled symptoms and radiographic abnormalities and improved pulmonary function in patients with APECED pneumonitis. Collectively, our findings unveil lung autoimmunity as a common, early, and unrecognized manifestation of APECED and provide insights into the immunopathogenesis and treatment of pulmonary autoimmunity associated with impaired central immune tolerance.

Utilize lung ultrasound B-lines and KL-6 to monitor anti-MDA-5 antibody-positive clinically amyopathic dermatomyositis-associated interstitial lung disease: a case report and literature review

In the past decade, lung ultrasound (LUS) B-lines and serum Krebs von den Lungen-6 (KL-6) antigen have been recognized as biomarkers of the connective tissue disease-associated interstitial lung diseases (CTD-ILDs). Robust data have demonstrated that B-lines total numbers and KL-6 levels are correlated with high-resolution computed tomography findings, pulmonary function test, and some clinical parameters in CTD-ILDs. However, limited data are available regarding the use of these two biomarkers to follow CTD-ILDs. Herein, we report a case with anti-melanoma differentiation-associated gene 5 antibody-positive clinically amyopathic dermatomyositis-associated ILD, successfully treated with high-dose methylprednisolone, cyclophosphamide, intravenous immunoglobulin, pirfenidone, and followed using lung ultrasound and KL-6.

Clinical Features of Anti-MDA5 Antibody-positive Rapidly Progressive Interstitial Lung Disease without Signs of Dermatomyositis

Anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody is associated with rapidly progressive interstitial lung disease (RP-ILD) in patients with clinically amyopathic dermatomyositis (CADM) or dermatomyositis (DM). We herein report three Japanese cases of anti-MDA5 antibody-positive RP-ILD without signs of CADM or DM. High-resolution computed tomography revealed patchy or subpleural distribution of consolidations and/or ground-glass opacities accompanied by traction bronchiectasis. All patients succumbed to respiratory failure within two months. Anti-MDA5 antibody-positive RP-ILD without signs of CADM or DM should be included in the differential diagnosis of acute/subacute ILD. Measurement of anti-MDA5 antibody and an intensive immunosuppressive regimen might rescue these patients from RP-ILD.

Serum neopterin as well as ferritin, soluble interleukin-2 receptor, KL-6 and anti-MDA5 antibody titer provide markers of the response to therapy in patients with interstitial lung disease complicating anti-MDA5 antibody-positive dermatomyositis

Objective: This study identified biomarkers that can be used to assess disease activity and response to therapy in patients with interstitial lung disease complicating anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab)-positive clinically amyopathic dermatomyositis (CADM). Methods: In 15 patients with interstitial lung disease complicating anti-MDA5 Ab-positive CADM, anti-MDA5 Ab, neopterin, interleukin (IL)-18, ferritin, and soluble interleukin 2 receptor (sIL-2R) levels were measured in cryopreserved serum specimens before and at multiple times after remission induction therapy, and their correlations were assessed. Results: Anti-MDA5 Ab, neopterin, IL-18, ferritin, and sIL-2R levels did not differ significantly between patients who survived and those who succumbed to the disease. In many cases, serum anti-MDA5 Ab titers were over the upper limit (over 150 index value) before treatment in the usual measuring method, and gradually decreased to the normal range at stable phase. Meanwhile, serum neopterin levels (21.6 [15.3-48.3] nmol/L) were significantly elevated in newly diagnosed patients and fell to 6.8 (5-11.4) nmol/L at 6 months after treatment introduction. Conclusions: Elevated serum neopterin as well as ferritin, sIL-2R, KL-6, and anti-MDA5 Ab titer might help identify patients with interstitial lung disease complicated with DM and might be useful in monitoring response to therapy.

Biomarkers in Adult Dermatomyositis: Tools to Help the Diagnosis and Predict the Clinical Outcome

Dermatomyositis pathophysiology is complex. In recent years, medical research has identified molecules associated with disease activity. Besides providing insights into the driving mechanisms of dermatomyositis, these findings could provide potential biomarkers. Activity markers can be used to monitor disease activity in clinical trials and may also be useful in daily practice. This article reviews molecules that could be used as biomarkers for diagnosis and monitoring dermatomyositis disease activity.

Anti-MDA5 antibody-positive hypomyopathic dermatomyositis complicated with pneumomediastinum

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive clinically amyopathic dermatomyositis (CADM) is frequently associated with rapidly progressive interstitial lung disease (RP-ILD) resulting in high mortality. Here we report a 51-year-old Japanese woman with anti-MDA5 antibody-positive hypomyopathic dermatomyositis (DM) who developed RP-ILD. She developed respiratory failure and pneumomediastinum, however her RP-ILD responded favorably to the combined immunosuppressive treatments consisting of steroids, intravenous cyclophosphamide and tacrolimus. She was complicated with severe infections, which were successfully managed by combined modality therapy including artificial ventilation and antibiotics in addition to immunosuppressive treatments in parallel to the decline of anti-MDA5 antibody titer (>150 Index to 75 Index). She was discharged after 6 months of treatment without any respiratory sequelae. Hypomyopathic DM patients with high titers of anti-MDA5 antibody should be treated with aggressive immunosuppressive therapies and closely monitored to prevent various infections.

Anti-MDA5 positive dermatomyositis complicated with rapidly progressive interstitial lung disease - a case report

CASE PRESENTATION

 We present a case of a 55-year-old Caucasian male with manifestations of dermatomyositis complicated with rapidly progressive interstitial lung disease (RP-ILD). Diagnosis of anti-MDA5 positive dermatomyositis was made.

DISCUSSION

 Myositis specific antibodies (MSA) can be used for diagnosis and predicting prognosis in patients with polymyositis and dermatomyositis. Anti-MDA5 positive dermatomyositis should be considered in patients presenting with dermatomyositis and a disease course resembling antisynthetase syndrome in the absence of antisynthetase autoantibodies, especially if a remarkably high ferritin is noted. Anti-MDA5 autoantibodies have been associated with RP-ILD and adverse outcome. In patients with anti-MDA5 autoantibodies, early diagnosis and aggressive immunosuppressive treatment may improve prognosis.

CONCLUSION

 This case highlights the importance of determining MSA in patients with dermatomyositis and associated interstitial lung disease, as this has implications for diagnosis, prognosis and therapy.