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.

The long-term outcome of interstitial lung disease with anti-aminoacyl-tRNA synthetase antibodies.

RATIONALE: Anti-aminoacyl transfer RNA synthetase antibodies (anti-ARS) are a group of myositis-specific autoantibodies that are detected in the sera of patients with polymyositis and dermatomyositis (PM/DM) and also in those of patients with idiopathic interstitial pneumonias without any connective tissue disease (CTD), including PM/DM. Although we reported the clinical characteristics of interstitial lung disease with anti-ARS antibodies (ARS-ILD) with and without PM/DM, the long-term prognosis of ARS-ILD remains undetermined. As our previous studies revealed that ARS-ILD without PM/DM was similar to CTD-associated ILD, and that ARS-ILD with PM/DM was radiologically suggestive of a nonspecific interstitial pneumonia (NSIP) pathological pattern, we hypothesized that the prognosis of ARS-ILD might be distinct from that of idiopathic pulmonary fibrosis (IPF) without anti-ARS. OBJECTIVES: To elucidate the long-term outcome of ARS-ILD with and without PM/DM and compare it to that of IPF. METHODS: A two-center retrospective study was conducted. The study population comprised 36 patients with ARS-ILD (8 with PM, 12 with DM, and 16 without myositis throughout the course), 100 patients with IPF without anti-ARS, and 7 patients with NSIP without anti-ARS. The presence of anti-ARS was determined by RNA immunoprecipitation using the sera obtained at the time of diagnosis before specific treatment. MEASUREMENTS AND MAIN RESULTS: During the observational period (median 49 months; range, 1-114 months), 7 patients with ARS-ILD (19%; 3 with PM, 1 with DM, and 3 without PM/DM) and 51 patients with IPF (51%) died. Patients with ARS-ILD had better overall survival than those with IPF (log-rank test, P < 0.001) and similar survival compared to those with NSIP (log-rank test, P = 0.59). The prognosis for patients with ARS-ILD was similar between those with and without myositis (log-rank test, P = 0.91). At the median follow-up time of 76.5 months, 14 of the 36 patients with ARS-ILD had deteriorated. Both a decline in forced vital capacity or an initiation of long-term oxygen therapy during the course (odds ratio [OR], 5.34) and acute exacerbation (OR, 28.4) significantly increased the mortality risk. CONCLUSIONS: The long-term outcome of ARS-ILD was significantly better than that of IPF regardless of the presence or absence of myositis.

Zoonotic necrotizing myositis caused by Streptococcus equi subsp. zooepidemicus in a farmer.

BACKGROUND: Streptococcus equi subsp. zooepidemicus is a beta-hemolytic group C streptococcus mainly causing infections in domesticated animals. Here we describe the first case of zoonotic necrotizing myositis caused by this bacterium. CASE PRESENTATION: The patient was a 73-year-old, previously healthy farmer with two asymptomatic Shetland ponies in his stable. After close contact with the ponies while feeding them, he rapidly developed erythema of his left thigh and sepsis with multiple organ failure. The clinical course was severe and complicated, requiring repetitive surgical excision of necrotic muscle, treatment with vasopressors, mechanical ventilation and continuous venovenous hemofiltration, along with adjunctive hyperbaric oxygen therapy. The patient was discharged from hospital at day 30, without obvious sequelae. The streptococcal isolate was identified as Streptococcus equi by MALDI-ToF MS, and was later assigned subspecies identification as S. equi subsp. zooepidemicus. Multilocus sequence typing identified the strain as a novel sequence type (ST 364), closely related to types previously identified in horses and cattle. A focused proteomic analysis revealed that the ST 364 expressed putative virulence factors similar to that of Streptococcus pyogenes, including homologues of the M protein, streptodornases, interleukin 8-protease and proteins involved in the biosynthesis of streptolysin S. CONCLUSION: This case illustrates the zoonotic potential of S. equi subsp. zooepidemicus and the importance of early clinical recognition, rapid and radical surgical therapy, appropriate antibiotics and adequate supportive measures when necrotizing soft tissue infection is suspected. The expression of Streptococcus pyogenes-like putative virulence determinants in ST 364 might partially explain the fulminant clinical picture.

[Dermatomyositis-update]. / Dermatomyositis - update.

Dermatomyositis is a rare idiopathic inflammatory myopathy that affects adults and children, mostly female. Hallmarks of the disease are myositis with necrosis, regeneration and perifascicular atrophy accompanied by a typical skin rash with heliotrope erythema, Gottron's sign, Gottron's papules and nail fold changes with splinter hemorrhage. Typical skin symptoms may appear 6 months up to 2 years before muscle involvement (amyopathic dermatomyositis). New myositis-specific antibodies may allow clinicoserologic correlations within a heterogeneous clinical spectrum. Autoantibody profiles, subtype of myositis, overlap with other collagen vascular disorders and/or malignancy (paraneoplastic dermatomyositis) as well as age of the patients all have a considerable impact on course and prognosis. Infections, drugs and tumors may trigger activation of T and B cells, plasmacytoid dendritic cells, overproduction of type I interferons and complement-mediated endothelial cell damage resulting in vasculopathy. UV radiation may also trigger dermatomyositis. Oral corticosteroids (1.5-2.0 mg/kg body weight/day) are the mainstay of treatment until improvement of muscle symptoms and/or normalization of muscle enzymes with subsequent slow tapering. Corticosteroids may be given as monotherapy or combined with steroid-sparing immunosuppressive agents' i.e. azathioprine, methotrexate, mycophenolate mofetil or high-dose intravenous immunoglobulins. Prognosis has improved considerably since use of high-dose corticosteroids, from 50 to 90% response rate. New therapies with biologicals (anti-CD20-, anti-TNFalpha-, anti-interferon antibodies) and Janus kinase inhibitors are currently being evaluated.

Innate immune-response mechanisms in dermatomyositis: an update on pathogenesis, diagnosis and treatment.

Dermatomyositis (DM) is an autoimmune disease mainly affecting muscle and skin. Typical clinical and laboratory findings include muscle weakness with elevated muscle enzymes, characteristic skin lesions (e.g., Gottron papules, heliotrope erythema, Shawl sign), and specific serum autoantibodies. Recent studies have highlighted the activation of the innate immune system, including high expression of interferons (IFNs) and IFN-regulated proteins, as an important pathological hallmark of DM. These findings have changed our understanding of the disease fundamentally, since inappropriate activation of the innate immune system with secondary dysregulation of the adaptive immune response is now considered to be a central pathogenetic feature of DM. In this article, we review current guidelines and standards in diagnosis and treatment. We detail evidence-based and pathophysiology-based treatment strategies, with a focus on skin as well as on muscle lesions. Particularly, we discuss how the recent advances in the understanding of the pathomechanisms of DM have altered our conception of the mode of action of established drugs such as chloroquine and methotrexate. Finally, we outline possible future treatment strategies, with a focus on the innate immune system, e.g., targeting the IFN system with the anti-IFN-α antibody sifalimumab.

Dermatomyositis and polymyositis: from immunopathology to immunotherapy (immunobiologics).

Idiopathic inflammatory myopathies (IIM), which include dermatomyositis (DM) and polymyositis (PM), are chronic systemic diseases associated with high morbidity and functional disability. Current treatment is based on the use of glucocorticoids and immunosuppressive drugs, but a considerable number of patients is refractory to traditional therapy. That has led to the attempted use of biologics based on the physiopathogenesis of IIM. From the immunopathological viewpoint, PM and DM differ: the former is more related to cellular immunity, while the latter, to humoral immunity. In both, however, elevated concentrations of proinflammatory interleukins (TNF, IL-1, IL-6) and increased expression of molecules related to costimulation of T lymphocytes have been described; thus, the use of biologics in those conditions seems reasonable. Considering the biologics available, open-label studies are scarce, comprising mainly case reports and series. TNF blockers have yielded conflicting results, with no evidence of good response to treatment. The anti-CD20 therapy has the most promising results. Data on T lymphocyte costimulation blockade and anti-IL-6 therapy are extremely scarce, preventing any consideration. Thus, the use of biologics in IIM still remains an unconquered frontier. Biologics may have an important role in the management of IIM refractory to conventional therapy, but further prospective studies based on objective parameters of response to treatment are needed. So far, anti-CD20 therapy seems to be the most promising treatment for refractory IIM.

Dermatomiosite e polimiosite: da imunopatologia à imunoterapia (imunobiológicos) / Dermatomyositis and polymyositis: from immunopathology to immunotherapy (immunobiologics)

As miopatias inflamatórias idiopáticas (MII), das quais fazem parte a dermatomiosite (DM) e a polimiosite (PM), são doenças sistêmicas crônicas associadas a alta morbidade e incapacidade funcional. O tratamento atual baseia-se na corticoterapia e no uso de imunossupressores, porém uma parcela considerável dos pacientes é refratária à terapia tradicional. Isso tem levado à tentativa de uso de imunobiológicos nesses pacientes, tendo por fundamento a fisiopatogênese das MII. Do ponto de vista imunopatológico, há diferenças entre PM e DM: a primeira está mais relacionada à imunidade celular, enquanto na segunda o papel humoral parece mais importante. Em ambas, porém, são descritas concentrações elevadas de interleucinas pró-inflamatórias (TNF, IL-1, IL-6) e aumento da expressão de moléculas relacionadas à coestimulação dos linfócitos T - nessas condições, parece racional o uso da terapia biológica. Considerando os imunobiológicos disponíveis, são escassos os dados de trabalhos abertos na literatura, compostos principalmente por séries e relatos de casos. Os bloqueadores do TNF apresentam resultados conflitantes sem evidência de boa resposta ao tratamento. A terapia anti-CD20 possui os resultados mais promissores. É extremamente escassa a informação sobre o bloqueio da coestimulação do linfócito T e a terapia anti- IL-6, que impede qualquer consideração. Dessa maneira, o uso de imunobiológicos em MII ainda permanece como fronteira a ser explorada. A terapia biológica pode ter papel relevante no tratamento das MII refratárias à terapia convencional; no entanto, novos estudos prospectivos com base em parâmetros objetivos de resposta ao tratamento são necessários. Até o momento, a terapia anti-CD20 parece ser a mais promissora no tratamento das MII refratárias.

Idiopathic inflammatory myopathies (IIM), which include dermatomyositis (DM) and polymyositis (PM), are chronic systemic diseases associated with high morbidity and functional disability. Current treatment is based on the use of glucocorticoids and immunosuppressive drugs, but a considerable number of patients is refractory to traditional therapy. That has led to the attempted use of biologics based on the physiopathogenesis of IIM. From the immunopathological viewpoint, PM and DM differ: the former is more related to cellular immunity, while the latter, to humoral immunity. In both, however, elevated concentrations of proinflammatory interleukins (TNF, IL-1, IL-6) and increased expression of molecules related to costimulation of T lymphocytes have been described; thus, the use of biologics in those conditions seems reasonable. Considering the biologics available, open-label studies are scarce, comprising mainly case reports and series. TNF blockers have yielded conflicting results, with no evidence of good response to treatment. The anti-CD20 therapy has the most promising results. Data on T lymphocyte costimulation blockade and anti-IL-6 therapy are extremely scarce, preventing any consideration. Thus, the use of biologics in IIM still remains an unconquered frontier. Biologics may have an important role in the management of IIM refractory to conventional therapy, but further prospective studies based on objective parameters of response to treatment are needed. So far, anti-CD20 therapy seems to be the most promising treatment for refractory IIM.

Molecular analysis of a major antigenic region of the 240-kD protein of Mi-2 autoantigen.

Anti-Mi-2 autoantibody is strongly associated with dermatomyositis and found in sera of 20% of patients. Mi-2 antigen contains at least eight components and previous evidence suggested that the 240-kD protein was the antigenic component for at least some sera. In this study, anti-M-2 patient sera were used to screen human thymocyte and HeLa cell lambda gt11 expression libraries, and two clones from each had plaques specifically reactive with anti-Mi-2 sera. Studies with affinity-purified antibody supported the identification of the clones. All of 44 anti-Mi-2 sera reacted with the plaques, but none of 44 control sera reacted significantly. The cDNAs were identical, and full sequencing of one revealed an open reading frame spanning a 1,054-bp insert. Rescreening the library with the cDNA yielded a 1,589-bp cDNA that continued the open reading frame. The Mi-2 cDNA hybridized to a single 7.5-8.0 kb mRNA of HeLa cells, by Northern blot. Rabbit antiserum directed at a portion of the cDNA product reacted with HeLa 240-kD Mi-2 protein. The sequence was notable for four potential zinc-fingers and several charged regions. The protein encoded by the cDNA produced in vitro reacted with only one of five of the Mi-2 sera. These findings indicate that the Mi-2 240 kD is a novel protein that is antigenic for all Mi-2 sera, and strongly suggests that a major common epitope is conformational in nature.

Dermatomyositis occurring during psoralen A (PUVA) therapy.

Dermatomyositis (DM) developed in a 35-year-old woman after 2 months of psoralen ultraviolet-A (PUVA) therapy for presumed psoriasis. Her disease was characterized by symmetrical proximal muscle weakness and cutaneous lesions compatible with DM. In addition, laboratory abnormalities included a positive antinuclear antibody, and elevated levels of creatine kinase and aldolase. This is the first report of DM developing during PUVA therapy.