Autoantibodies in adult patients with idiopathic inflammatory myopathies in Buenos Aires

The idiopathic inflammatory myopathies(IIM) are a heterogeneous group of diseases of the skeletal muscle. On the basis of clinical, serologic and histological differences, they are classified in dermatomyositis (DM), polymyositis (PM), inclusion body myositis and immunomediated necrotizing myopathy. Autoantibodies directed against nuclear and cytoplasmic antigens are present with variable frequencies among studies. Myositis-specific antibodies (MSAs) are useful in IIM because they contribute to the diagnosis, help to identify different clinical subsets, and have prognostic value. This study aimed to explore the frequency of autoantibodies, especially MSAs, and their relationship with clinical features in adult patients with DM, PM and overlap syndrome. Medical records were reviewed. Myositis-associated antibodies (non-specific) and MSAs (anti Jo-1, PL-7, PL-12, Mi-2 and SRP) were measured using commercial kits. Twelve patients had MSAs, an overall frequency similar to those of international series, but PL-12 and Mi-2 were more frequent than Jo-1, which is the most frequently observed elsewhere. All five patients with Mi-2 had classical DM with a favorable response to treatment. Interstitial pneumonia (n: 4) and/or treatment-refractory disease (n: 3) were found in the presence of anti-PL-12, alone or associated with anti-SRP and/or Jo-1. In conclusion, the coexistence of AEM, a rare finding, was found in three patients. The presence of MSAs aided to the diagnosis of IIM, in particular in those patients without available or conclusive biopsy results.

Las miopatías inflamatorias idiopáticas (MII) comprenden un grupo heterogéneo de enfermedades adquiridas del músculo esquelético. Según sus características clínicas, serológicas e histológicas se las clasifica en dermatomiositis (DM), polimiositis (PM), miopatía necrotizante autoinmune y miositis por cuerpos de inclusión. Los anticuerpos específicos de miositis (AEMs) contribuyen al diagnóstico, permiten distinguir formas clínicas y tienen valor pronóstico. Con el objetivo de explorar la frecuencia de autoanticuerpos, en particular AEMs, y su relación con las características clínicas de las MII del adulto, se revisaron las historias clínicas de 25 pacientes con DM, PM y síndromes de superposición, asistidos en nuestro centro entre 1999 y 2013. La presencia de autoanticuerpos asociados a miositis (no específicos) y AEMs (anti Jo-1, PL-7, PL-12, Mi-2, SRP) se investigó utilizando kits comerciales. Doce pacientes presentaron AEMs, frecuencia global similar a la encontrada en series internacionales, pero a diferencia de lo observado en otros países, anti-PL-12 y anti-Mi-2 fueron más frecuentes que anti-Jo-1. Los cinco pacientes con anti-Mi-2 tuvieron DM clásica y buena evolución clínica. Anti-PL-12, ya sea solo o asociado a anti-SRP y/o anti-Jo-1, estuvo presente en pacientes con neumonía intersticial (n:4) y/o enfermedad refractaria al tratamiento (n: 3). En conclusión, la coexistencia de AEM, hallazgo raro, se encontró en tres pacientes. La presencia de AEMSs contribuyó al diagnóstico de MII, en particular en aquellos casos sin resultados concluyentes de biopsia de músculo.

Expressão de antígenos MHC classe I e de células CD4 e CD8 na polimiosite e dermatomiosite / MHC class I antigens, CD4 and CD8 expressions in polymyositis and dermatomyositis

Objetivo: Analisar as frequências de expressão dos antígenos de complexo principal de histocompatibilidade classe I (MHC-I) e células CD4 e CD8 no músculo esquelético na polimiosite (PM) e dermatomiosite (DM). Métodos: Estudo retrospectivo de 34 casos de PM, oito casos de DM e 29 controles com miopatias não inflamatórias. Resultados: Os antígenos MHC-I expressaram-se no sarcolema e/ou sarcoplasma em 79,4% dos casos de PM, 62,5% dos casos de DM e 27,6% dos controles (a expressão de CD4 foi observada em 76,5%, 75% e 13,8%, respectivamente). Quando os antígenos de MHC-I foram coexpressados com CD4, houve elevada suspeita de PM/DM (principalmente PM). Em 14,3% dos casos de PM/DM, observou-se a expressão isolada dos antígenos MHC-I, sem células inflamatórias. Conclusão: A expressão dos antígenos MHC-I e a positividade do CD4 podem aumentar a suspeita diagnóstica de PM/DM. Não foi observado infiltrado celular em 14,3% dos casos. .

Objective: To analyze the frequencies of the expression of major histocompatibility complex class I (MHC-I) antigens, and CD4 and CD8 cells in skeletal muscle in polymyositis (PM) and dermatomyositis (DM). Methods: This was a retrospective study of 34 PM cases, 8 DM cases, and 29 control patients with non-inflammatory myopathies. Results: MHC-I antigens were expressed in the sarcolemma and/or sarcoplasm in 79.4% of PM cases, 62.5% of DM cases, and 27.6% of controls (CD4 expression was observed in 76.5%, 75%, and 13.8%, respectively). There was a high suspicion of PM/DM (mainly PM) in participants in whom MHC-I antigens and CD4 were co-expressed. In 14.3% of PM/DM cases, we observed MHC-I antigens expression alone, without inflammatory cells. Conclusion: MHC-I antigens expression and CD4 positivity might add to strong diagnostic suspicion of PM/DM. No cellular infiltration was observed in approximately 14.3% of such cases. .

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.

Differential Immunohistological Features of Inflammatory Myopathies and Dysferlinopathy

This study was performed in order to characterize the types of the infiltrating cells, and the expression profiles of major histocompatibility complex (MHC) class I and membrane attack complex (MAC) in patients with inflammatory myopathies and dysferlinopathy. Immunohistochemical stains were performed using monoclonal antibodies against several inflammatory cell types, MHC class I, and MAC in muscles from inflammatory myopathies and dysferlinopathy. There was significant difference in the types of infiltrating cells between polymyositis (PM), dermatomyositis (DM), and dysferlinopathy, including significantly high CD4+/CD8+ T cell ratio and B/T cell ratio in DM. In dysferlinopathy, CD4+ T cells were the most abundant and the proportions of infiltrating cell types were similar to those of DM. MHC class I was expressed in muscle fibers of PM and DM regardless of the presence of inflammatory infiltrates. MAC was expressed in necrotic fibers and vessels of PM and DM. One patient with early stage DM had a MAC deposits on endomysial capillaries. In dysferlinopathy, MAC deposit was also observed on the sarcolemma of nonnecrotic fibers. The analysis of inflammatory cells, MHC class I expressions and MAC deposits may help to differentiate dysferlinopathy from idiopathic inflammatory myopathy.

Successful Combination Therapy of Cyclosporine and Methotrexate for Refractory Polymyositis with Anti-Jo-1 Antibody: A Case Report

Although corticosteroids have been the initial agent for the treatment of inflammatory myopathies (IM), immunosuppressive agents such as azathioprine, methotrexate, cyclophosphamide, or cyclosporine are commonly required to control the disease except mild cases. On the other hand, the efficacy of combination therapy of cyclosporine and methotrexate in severe rheumatoid arthritis has been proven without serious side effects. However, in treatment-resistant myositis, the experience of such a therapy is very limited, and has not been described in refractory polymyositis with anti-Jo-1 antibody. Here, we report a young female patient with recalcitrant polymyositis and anti-Jo-1 antibody who was successfully treated with the combination therapy of cyclosporine and methotrexate. At first, the myositis did not respond to several agents, such as corticosteroid, monthly pulse cyclophosphamide, azathioprine, or cyclosporine. Methotrexate was initially avoided as treatment regimen because of its potential pulmonary toxicity in the case with preexisting lung disease.

Inflammatory myopathies--a clinicopathologic study.

In this study, clinical, histopathological and immunological profiles were analysed in ten patients with inflammatory myopathies. Polymyositis and dermatomyositis were more common than other forms of inflammatory myopathies. The pathogenetic mechanisms and distinguishing histopathological and immunological profiles between polymyositis and dermatomyositis have been highlighted.

Polidermatomiosites: atualizaçäo de aspectos diagnósticos, imunopatogênicos e terapêuticos / Polydermatomyositis: updating of diagnostic, immunopathogenic and therapeutic aspects

As miopatias inflamatórias se constituem em desafio para o clínico, que encontra dificuldades em seu diagnóstico e em seu tratamento. Os clássicos critérios de Bohan & Peter, quando preenchidos, näo bastam para o diagnóstico de polimiosite e dermatomiosite, uma vez que diversas outras doenças infecciosas e tóxicas poderäo se apresentar da mesma maneira. Sua fisiopatogenia ainda é incompletamente conhecida, mas fenômenos vasculares e de imunidade humoral estäo na primeira linha do raciocínio, ressaltando-se aqui os anticorpos contra tRNA-sintetases (Jo-1, PL-7, Pl-12, EJ, KJ, OJ), que marcam o subgrupo de polimiosite e fibrose pulmonar, e os anticorpos contra o antígeno MI-2, que marcam os pacientes com dermatomiosite. O tratamento deve ser iniciado com prednisona em doses imunossupressoras, associada ou näo a citotóxicos, e mantido por meses. A terapêutica com ciclosporina A, plamaferese, imunoglobulinas endovenosas e irradiaçäo linfóide permanece experimental