Caracterización clínico-radiológica de pacientes con enfermedad pulmonar intersticial y panel de miositis positivo en hospital Santiago Oriente / Clinical-radiological characterization of patients with interstitial lung disease and positive myositis panel at hospital Santiago Oriente

Introducción: Las Enfermedades Pulmonares Intersticiales (EPI) afectan principalmente al intersticio pulmonar, con importante morbimortalidad asociada. Tienen un espectro de posibles etiologías que es cada vez más amplio. Hay una importante causalidad a partir de Enfermedades del Tejido Conectivo (ETC), describiéndose cada vez más casos asociados a Síndrome Antisintetasa, y con diversos patrones radiológicos según serología obtenida, agrupada en "Panel de Miositis" (PaM). El presente estudio de cohorte retrospectiva reúne PaMs realizados en el Hospital Santiago Oriente, correlacionando resultados con manifestaciones clínicas e imagenológicas. Material y Métodos: Se recuperaron 33 PaMs realizados entre 2017 y 2022, y a través de revisión de fichas de los pacientes de quienes provenían las PaMs se consignaron las principales manifestaciones clínicas, imagenológicas y de la serología reumatológica complementaria, estableciendo correlaciones entre múltiples variables. Resultados: Hubo 15 pacientes PaM positivos (45,4%), 8 de ellos (53%) ya contaban con alguna miopatía inflamatoria diagnosticada. Los principales hallazgos clínicos consignados fueron pápulas de Gottron, artritis, eritema heliotropo, Fenómeno de Raynaud y fiebre. El anticuerpo positivo más frecuente fue Ro-52. Se pudo objetivar ANA positivo en 10 casos (66,7%). Se identificó EPI en 66,7% de aquellos con PaM positivo, siendo la Neumonía Intersticial no específica fibrótica con Neumonía en Organización la manifestación más frecuente. No hubo asociación significativa entre manifestaciones imagenológicas y anticuerpos específicos. Se encontró ANA 1/80 en 66,7% de los casos, lo cual no se asoció a mayor riesgo de EPI. Conclusiones: Existe asociación entre varias ETC y las EPI. Destaca la importancia de los hallazgos clínicos para establecer un adecuado índice de sospecha, para dirigir oportunamente el estudio complementario (ej: PaM), y la eventual terapia específica.

Introduction: Interstitial Lung Diseases (ILD) mainly affect the pulmonary interstitium, with significant associated morbidity and mortality. They have a spectrum of possible etiologies that is increasingly broad. There is an important causality from Connective Tissue Diseases (CTD), describing more and more cases associated with Antisynthetase Syndrome, and with different radiological patterns according to the serology obtained, enclosed into "Panel of Myositis" (PaM). This retrospective cohort study gathers PaMs performed at Hospital Santiago Oriente, PaM results are correlated with clinical and imaging manifestations. Material and Methods: 33 PaMs performed between 2017 and 2022 were saved up and by reviewing the clinical records of the patients from whom the PaMs came, their clinical and radiological manifestations and the results of their complementary rheumatological serology were recorded to establish correlations between multiple variables. Results: There were 15 positive PaMs (45.4%), 8 (53%) of them already had some diagnosed inflammatory myopathy. The main clinical findings reported were Gottron's papules, arthritis, heliotrope erythema, Raynaud's phenomenon, and fever. The most frequent positive antibody detected was Ro-52. Positive ANA could be found in 10 cases (66.7%). PID was identified in 66.7% of those with a positive PaM, being non-specific fibrotic Interstitial Pneumonia with Organizing Pneumonia being the most frequent manifestation. There was no significant association between imaging manifestations and specific antibodies. ANA 1/80 was found in 6.7% of the cases, which was not associated with an increased risk of PID. Conclusions: There is association between several CTEs and EPIs. It is necessary to highlight the importance of the clinical findings to establish an adequate index of suspicion, in order to timely direct the complementary study (eg: PaM), and the eventual specific therapy.

Contribución del panel de miositis en el estudio de pacientes con enfermedades pulmonares intersticiales y sospecha de enfermedad del tejido conectivo / Contribution of myositis panel in the study of patients with interstitial lung disease and suspicion of connective tissue disease

INTRODUCCIÓN: La manifestación extramuscular de las miopatías inflamatorias idiopáticas (MII) es la enfermedad pulmonar intersticial (EPI) y el diagnóstico se basa en autoanticuerpos séricos. Los nuevos anticuerpos específicos y asociados a MII han ayudado a identificar nuevas entidades clínicas en el espectro de MII. El objetivo de este estudio es evaluar la contribución diagnóstica de un panel de anticuerpos de miositis (PM) en una cohorte de pacientes chilenos con EPI sin una enfermedad del tejido conectivo (ETC) definitiva. MATERIALES Y MÉTODOS: A partir de enero de 2017 se realizó un panel de miositis a 111 pacientes consecutivos con EPI y sospecha de ETC, pero sin un diagnóstico definitivo a través de otra herramienta diagnóstica, en el programa de Pulmón-Reumatológico del Instituto Nacional del Tórax, Santiago, Chile. Se compararon las características basales clínicas y serológicas de los pacientes que se asociaban más frecuentemente a la probabilidad de tener un panel positivo. RESULTADOS: El PM fue positivo en 56 de 111 pacientes. El síndrome antisintetasa (SAS) fue el diagnóstico más frecuente. Los anticuerpos más frecuentes fueron Ro-52, PM / Scl-75 y Ku. Las variables más frecuentes en el grupo PM(+) fueron la presencia del Raynaud, miositis, manos de mecánico, los anticuerpos Ro y La positivos, la presencia de un patrón combinado de neumonía intersticial inespecífica y neumonía organizada en la tomografía computarizada de tórax. CONCLUSIONES: la incorporación del PM nos ha ayudado a mejorar nuestra precisión diagnóstica en pacientes con EPI / ETC. Presentamos elementos clínicos y serológicos que perfeccionan el rendimiento de la prueba.

INTRODUCTION: The most common extramuscular manifestation of the idiopathic inflammatory myopathies (IIM) is interstitial lung disease (ILD) and the diagnosis is based on serum autoantibodies. The new specific and associated antibodies to IIM have helped to identify new clinical entities in the spectrum of IIM. The objective of this study is to evaluate the diagnostic contribution of a myositis antibodies panel (MP) in a cohort of Chilean patients with ILD without a definitive connective tissue disease (CTD). MATERIALS AND METHODS: Starting on January 2017 we performed a MP to 111 consecutive patients with ILD and suspected CTD but without a definitive diagnosis through another diagnostic tools in the Lung-Rheumatological Program at the "Instituto Nacional del Tórax", Santiago, Chile. The clinical and serological baseline characteristics of the patients that were most frequently associated with the probability of having a positive panel were compared. RESULTS: The MP was positive in 56 of 111 patients. Anti synthetase syndrome (ASS) was the most prevalent diagnosis. The most frequent antibodies were Ro-52, PM/Scl-75 and Ku. The most frequent variables in the positive MP group were the presence of Raynaud's phenomenon, myositis, mechanic's hands, positive Ro and La antibodies and the presence of combined pattern of nonspecific interstitial pneumonia and organizing pneumonia in chest computed tomography scan. CONCLUSIONS: The incorporation of the MP has helped us to improve our diagnostic precision of patients with CTD/ILD. We present clinical and serological elements that refine the performance of the test.

Anticuerpos en miopatías inflamatorias idiopáticas / Antibodies in idiopathic inflammatory myopathies

Las miopatías inflamatorias idiopáticas (MII) comprenden un grupo de enfermedades multisistémicas de baja prevalencia que afectan tanto adultos como a niños, con ma-nifestaciones clínicas variables como lo son: debilidad muscular de predominio proxi-mal, alteraciones cutáneas (pápulas de Gottron, signo del chal, ulceras cutáneas), artritis, enfermedad pulmonar intersticial difusa (EPD), calcinosis y malignidad; en-marcadas en diferentes subtipos clínicos. Se cree que la autoinmunidad tiene un pa-pel clave en la patogénesis de estas enfermedades y como tal se han identificado autoanticuerpos en más del 50% de los pacientes con MII (algunos específicos y otros relacionados a miositis), lo cual ha permito clasificar diferentes características fenotí-picas e histológicas de estas enfermedades al igual de reconocer diferentes patrones de respuesta a tratamiento y factores pronósticos.En esta revisión mencionaremos los autoanticuerpos mas conocidos en relación a las miopatías inflamatorias idiopáticas, incluida la identificación de anticuerpos asocia-dos con las miopatía necrotizantes autoinmunes (MNA), la miositis por cuerpos de inclusión (MCI) y la asociación miositis - cáncer.

The Idiopathic inflammatory myopathies (IIM) comprise a group of low prevalence multisitemic diseases that affect both adults and children, with variable clinical man-ifestations such as muscular weakness of predominantly proximal, skin alterations (Gottron papules, sign of the shawl, skin ulcers), arthritis, diffuse interstitial lung dis-ease (ILD), calcinosis and malignancy; framed in different clinical subtypes. It is be-lieved that autoimmunity plays a key role in the pathogenesis of these diseases and as such autoantibodies have been identified in more than 50% of patients with IIM (some specific and others related to myositis), which has allowed to classify different phenotypic characteristics and histological of these diseases as well as recognizing different patterns of response to treatment and prognostic factors.In this review we will mention the most known autoantibodies in relation to idio-pathic inflammatory myopathies, including the identification of antibodies associated with autoimmune necrotizing myopathies (ANM), inclusion body myositis (IBM) and the myositis - cancer association.

Significance of Myositis Autoantibody in Patients with Idiopathic Interstitial Lung Disease

PURPOSE: Some patients with interstitial lung disease (ILD) related to connective tissue disease (CTD) have a delayed diagnosis of the underlying CTD when the ILD is categorized as idiopathic. In this study, we evaluated the frequency of myositis autoantibodies in patients diagnosed with idiopathic ILD and investigated the clinical significance stemming from the presence of the antibodies. MATERIALS AND METHODS: A total 32 patients diagnosed with idiopathic ILD were enrolled in this study. We analyzed a panel of 11 myositis autoantibody specificities in the patients using a line blot immunoassay. Then, we divided them into myositis autoantibody-positive and -negative groups and compared the clinical features and laboratory data between the two groups. RESULTS: Of the 32 idiopathic ILD patients, 12 patients had myositis autoantibodies encompassing 9 specificities, except for anti-Mi-2 and anti-PM-Scl 100 (12/32, 38%). Anti-synthetase autoantibodies including Jo-1, EJ, OJ, PL-7, and PL-12 were present in 7 patients (7/32, 22%). The group with myositis autoantibodies presented more frequently with the symptom of mechanic's hand and showed abnormal pulmonary function test results with low forced vital capacity, diffusing capacity for carbon monoxide, total lung capacity, and high lactate dehydrogenase values in blood when compared with the group without myositis antibodies. CONCLUSION: We strongly suggest that patients undergo an evaluation of myositis autoantibodies, if they are diagnosed with idiopathic ILD in the presence of clinical characteristics including mechanic's hand, arthralgia, and autoantibodies which are insufficient to make a diagnosis of a specific CTD category.

Miopatía inflamatoria con compromiso inicial de músculos respiratorios y artritis reumatoidea

Las miopatías inflamatorias constituyen un grupo heterogéneo de enfermedades musculares adquiridas de presentación subaguda, crónica y a veces aguda. Las entidades clínicas más frecuentes son la dermatomiositis, la polimiositis, la miositis necrotizante autoinmune y la miositis por cuerpos de inclusión. Suelen presentarse con debilidad muscular con predominio proximal y simétrica, pero rara vez comprometen los músculos respiratorios. Presentamos el caso de una mujer de 39 años con miopatía inflamatoria inespecífica que presentó insuficiencia respiratoria secundaria a hipoventilación alveolar por debilidad muscular y requirió asistencia respiratoria mecánica. Respondió favorablemente y de forma rápida tras el tratamiento instaurado con inmunosupresores (corticoides y metotrexato) e inmunoglobulina humana endovenosa. Se utilizó ventilación no invasiva como alternativa a la intubación orotraqueal con adecuada tolerancia.

Inflammatory myopathies comprise a heterogeneous group of subacute, chronic and sometimes acute acquired muscle diseases. The most common inflammatory myopathies seen in practice can be separated into four distinct subsets: polymyositis, dermatomyositis, necrotizing autoimmune myositis and inclusion body myositis. These disorders present as proximal and symmetric muscle weakness but rarely respiratory muscles may also be affected. We report the case of a 39 year-old female with inflammatory myopathy with acute respiratory failure due to alveolar hypoventilation secondary to respiratory muscle dysfunction that required mechanical ventilation. The treatment with steroids, methotrexate and intravenous immune globulin was successful as well as the implementation of non-invasive ventilation as an alternative to endotracheal intubation.

Síndrome antissintetase: anti-PL-7, anti-PL-12 e anti-EJ / Anti-synthetase syndrome: anti-PL-7, anti-PL-12 and anti-EJ

OBJETIVOS: Devido à escassez de trabalhos na literatura, realizamos análise de uma série de pacientes com síndrome antissintetase (SAS) do tipo anti-PL-7, PL-12 e EJ. MÉTODOS: Estudo de coorte, retrospectivo, envolvendo 20 pacientes com SAS (8 com anti-PL-7, 6 com PL-12, 6 com EJ), em acompanhamento em nosso serviço, entre 1982 e 2012. RESULTADOS: A média de idade dos pacientes ao início da doença foi de 38,5 ± 12,9 anos, e a duração da doença de 4,5 ± 6,4 anos. Setenta por cento dos pacientes eram brancos e 85% eram mulheres. Sintomas constitucionais ocorreram em 90% dos casos. Todos apresentavam fraqueza muscular objetiva dos membros; ao diagnóstico, 30% encontravam-se acamados e 65% com disfagia alta. Envolvimento articular, pulmonar e fenômeno de Raynaud ocorreram, respectivamente, em 50%, 40% e 65% dos casos; mais da metade dos pacientes apresentava pneumopatia incipiente, opacidade em vidro-fosco e/ou fibrose pulmonar. Não houve casos de envolvimento neurológico e/ou cardíaco. Todos receberam prednisona e, como poupadores dessa medicação, diferentes imunossupressores, dependendo da tolerância, efeitos colaterais e/ou refratariedade da doença. De relevância, os pacientes com anti-EJ apresentaram maiores taxas de recidiva. Dois pacientes evoluíram para óbito ao longo do seguimento, e um paciente teve neoplasia mamária na ocasião do diagnóstico da doença. CONCLUSÕES: A SAS (anti-PL-7, PL-12 e EJ) afetou predominantemente mulheres brancas. Embora os autoanticorpos descritos no presente estudo estejam mais relacionados com o acometimento pulmonar comparativamente ao articular, nossos pacientes apresentaram uma porcentagem significativa de ambos e com percentagem alta de miopatia. Além disso, houve menor taxa de mortalidade.

OBJECTIVES: Due to the scarcity of studies in the literature, we conducted an analysis of a series of patients with the anti-PL-7, PL-12 and EJ types of antisynthetase syndrome (ASS). METHODS: We conducted a retrospective cohort study of 20 patients with ASS (8 with anti-PL-7, 6 with PL-12, 6 with EJ) monitored in our department between 1982 and 2012. RESULTS: The mean patient age at disease onset was 38.5 ± 12.9 years, and the disease duration was 4.5 ± 6.4 years. Of all the patients, 70% were white and 85% were female. Constitutional symptoms occurred in 90% of cases. All patients presented objective muscle weakness in the limbs; in addition, 30% were bedridden and 65% demonstrated high dysphagia at diagnosis. Joint and pulmonary involvement and Raynaud's phenomenon occurred in 50%, 40% and 65% of cases, respectively, with more than half of the patients presenting incipient pneumopathy, ground-glass opacity and/or pulmonary fibrosis. There were no cases of neurological and/or cardiac involvement. All patients received prednisone or other immunosuppressants depending on tolerance, side effects and/or disease refractoriness. Importantly, patients with the anti-EJ type of ASS demonstrated higher rates of recurrence. Two patients died during follow-up, and 1 patient had breast cancer at the time of diagnosis. CONCLUSIONS: ASS (anti-PL-7, PL-12 and EJ) was found to predominantly affect white women. Although the autoantibodies described in the present study are more related to pulmonary than joint involvement, our patients showed a significant percentage of both types of involvement and a high percentage of myopathy. We also observed a low mortality rate.

Myositis-specific and myositis-associated autoantibody profiles and their clinical associations in a large series of patients with polymyositis and dermatomyositis

OBJECTIVE: To analyze the prevalence of myositis-specific and myositis-associated autoantibodies and their clinical correlations in a large series of patients with dermatomyositis/polymyositis. METHOD: This cross-sectional study enrolled 127 dermatomyositis cases and 95 polymyositis cases. The disease-related autoantibody profiles were determined using a commercially available blood testing kit. RESULTS: The prevalence of myositis-specific autoantibodies in all 222 patients was 34.4%, whereas myositis-associated autoantibodies were found in 41.4% of the patients. The most frequently found autoantibody was anti-Ro-52 (36.9%), followed by anti-Jo-1 (18.9%), anti-Mi-2 (8.1%), anti-Ku (4.1%), anti-SRP (3.2%), anti-PL-7 (3.2%), anti-PL-12 (2.7%), anti-PM/Scl75 (2.7%), and anti-PM/Scl100 (2.7%). The distributions of these autoantibodies were comparable between polymyositis and dermatomyositis, except for a higher prevalence of anti-Jo-1 in polymyositis. Anti-Mi-2 was more prevalent in dermatomyositis. Notably, in the multivariate analysis, anti-Mi-2 and anti-Ro-52 were associated with photosensitivity and pulmonary disorders, respectively, in dermatomyositis. Anti-Jo-1 was significantly correlated with pulmonary disorders in polymyositis. Moreover, anti-Ro-52 was associated with anti-Jo-1 in both diseases. No significant correlation was observed between the remaining autoantibodies and the clinical and/or laboratory findings. CONCLUSIONS: Our data are consistent with those from other published studies involving other populations, although certain findings warrant consideration. Anti-Ro-52 and anti-Jo-1 were strongly associated with one another. Anti-Ro-52 was correlated with pulmonary disorders in dermatomyositis, whereas anti-Jo-1 was correlated with pulmonary alterations in polymyositis. .

Doença pulmonar intersticial relacionada a miosite e a síndrome antissintetase / Myositis-related interstitial lung disease and antisynthetase syndrome

Em pacientes com miosite, é comum o comprometimento pulmonar, e a presença de anticorpos anti-aminoacil-RNAt sintetase (anti-ARS) é preditora da presença ou do desenvolvimento de doença pulmonar intersticial (DPI). Uma entidade clínica distinta - a síndrome antissintetase - é caracterizada pela presença de anticorpos anti-ARS, miosite, DPI, artrite, fenômeno de Raynaud e "mãos de mecânico". O mais comum anticorpo anti-ARS é o anti-Jo-1. Anticorpos anti-ARS mais recentemente descritos podem conferir um fenótipo que é distinto daquele de pacientes com positividade para anti-Jo-1, sendo caracterizado por uma menor incidência de miosite e uma maior incidência de DPI. Nos pacientes com DPI relacionada à síndrome antissintetase, a resposta a medicações imunossupressoras é em geral favorável.

In patients with myositis, the lung is commonly involved, and the presence of anti-aminoacyl-tRNA synthetase (anti-ARS) antibodies marks the presence or predicts the development of interstitial lung disease (ILD). A distinct clinical entity-antisynthetase syndrome-is characterized by the presence of anti-ARS antibodies, myositis, ILD, fever, arthritis, Raynaud's phenomenon, and mechanic's hands. The most common anti-ARS antibody is anti-Jo-1. More recently described anti-ARS antibodies might confer a phenotype that is distinct from that of anti-Jo-1-positive patients and is characterized by a lower incidence of myositis and a higher incidence of ILD. Among patients with antisynthetase syndrome-related ILD, the response to immunosuppressive medications is generally, but not universally, favorable.

Síndrome antissintetase anti-Jo-1 / Anti-Jo-1 antisynthetase syndrome

OBJETIVO: Devido à escassez de estudos populacionais, apresentamos um estudo epidemiológico em síndrome antissintetase anti-Jo-1 (SAS). PACIENTES E MÉTODOS: Estudo coorte retrospectivo realizado em um centro de 1980 a 2010. Dados clínico-laboratoriais e demográficos foram obtidos dos prontuários médicos. Todos os pacientes preenchiam critério de Bohan e Peter (1975) e apresentavam anti-Jo-1, além de envolvimento articular, muscular e pulmonar. Dezoito pacientes com SAS anti-Jo-1 foram analisados. RESULTADOS: A média de idade ao início da doença foi de 39,9 ± 15,7 anos, e a média da duração da doença, 9,7 ± 7,0 anos. Todos os pacientes eram brancos, e 94,4 por cento eram mulheres. Sintomas constitucionais ocorreram em metade dos casos. Envolvimento cutâneo e do trato gastrointestinal ocorreram, respectivamente, em 66,6 por cento e 55,6 por cento dos casos. Não houve casos de envolvimento neurológico ou cardíaco. Metade dos pacientes apresentava pneumopatia incipiente, opacidade em vidro-fosco e fibrose pulmonar basal. Houve um caso de tuberculose, três de herpes zoster e um linfoma não Hodgkin. Um óbito ocorreu devido ao choque séptico (broncopneumonia hospitalar). Todos os pacientes receberam prednisona (1mg/kg/dia) e 12 (66,7 por cento) receberam pulsoterapia com metil prednisolona (1 g/dia, 3 dias). Diferentes imunossupressores foram utilizados como poupadores de corticosteroide, dependendo da tolerância, efeitos colaterais e/ou refratariedade da doença. Embora a recidiva da doença (clínica e/ou laboratorial) tenha ocorrido em 87,5 por cento dos casos, 12 dos 16 pacientes (75 por cento) estavam com a remissão da doença no desfecho do presente estudo. CONCLUSÃO: A maioria dos pacientes eram mulheres brancas e com alta taxa de recidiva da doença.

OBJECTIVE: Given a lack of population-based studies, we report an epidemiological-clinic study of anti-Jo-1 antisynthetase syndrome (ASS). PATIENTS AND METHODS: To study a retrospective cohort of a single-center from 1980 to 2010. Clinical-laboratory and demographic data were obtained from medical files. All patients fulfilled the Bohan and Peter criteria (1975) and presented anti-Jo-1, articular, muscle and lung involvement. Eighteen patients with anti-Jo-1 ASS were analyzed. RESULTS: The mean age at disease onset was 39.9 ± 15.7 years and average disease duration was 9.7 ± 7.0 years. All subjects were white, and 94.4 percent were female. Constitutional symptoms occurred in 50 percent of cases. There was cutaneous and gastrointestinal tract involvement in 66.6 percent and 55.6 percent of cases, respectively. No cases manifested neurologic or cardiac involvement. Half of the patients showed incipient pneumopathy, ground-glass opacities and basal pulmonary fibrosis. There was one case of tuberculosis, three of herpes zoster and one of non-Hodgkin lymphoma. One death occurred due to sepsis shock (hospital bronchopneumonia). All patients received prednisone (1mg/kg/day) and 12 (66.7 percent) participants received methyl prednisolone pulse therapy (1g/day, 3 days). Various immunosuppressants were used as corticosteroid tapers, depending on tolerance, side effects and/or refractoriness. Although disease relapse (clinical and/or laboratory) occurred in 87.5 percent of cases, 12 out of 16 patients (75 percent) were in disease remission at study endpoint. CONCLUSION: In the present study, almost all patients were white females and the disease relapse rate was high.

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.

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.

Effect of myosin B on guinea pig muscles--light microscopic and immunological aspects.

Experimental myositis was induced in guinea pigs by multiple inoculations with Myosin B fraction of the rabbit skeletal muscle. Quantitative histopathological features were studied and they include necrosis, central nucleation, inflammatory cellular reaction. Besides myositis, features of myocarditis were evident in 40% animals. Circulating immune complexes (CICs) in the sera of experimental animals were isolated by a polyethylene glycol (PEG) precipitation method. Presence of antimyosin B antibody in the immune complexes was characterised by an enzyme-linked immunosorbent assay. The role of circulating immune complexes in pathogenesis of experimental myositis and human polymyositis have been emphasised.

Tropical myositis. A clinical immunological and histopathological study.

Thirty cases of tropical myositis, (22 suppurative, 8 non-suppurative) aged 11 to 65 years were seen in a period of one year. There were 22 males and 8 females. There was a total of 78 muscular lesions in 22 suppurative cases and 19 muscular lesions in 8 non-suppurative cases. The most common presentation was localised myalgia (100%), fever (96.7%) generalized myalgia (56.7%), arthralgia (40%), pain in abdomen (33.3%) and breathlessness (30%). Extramuscular complications were present in 50% cases. Twenty four muscle biopsies were taken. Sixteen showed changes of suppurative myositis i.e. non-specific acute inflammatory reaction, muscle necrosis with myocytolysis, vacuolation of cytoplasm and loss of striations. Cell mediated immunity was found to be suppressed in patients of non-suppurative myositis in comparison with the suppurative group. IgG, IgA and IgM were significantly raised in patients in comparison to controls (p less than 0.05). The intact humoral immunity indicates good response to acute phase reaction and increased levels of IgG, IgA and IgM (specially IgG) can be taken as good prognostic parameter.

Miosite imunológica experimental / Immunological experimental myositis

Dezenove ratos de raça Lewis foram submetidos a injeçöes de extrato muscular heterológo de coelho e o tecido muscular avaliado por métodos de coloraçöes histoquímicas. Ocorreram disfunçöes inespecíficas nas fibras musculares e infiltrado inflamatório semelhante aos observados na dermatopolimiosite humana em oito animais evidenciando o envolvimento imunológico no desencadeamento da doença

Miosite imunológica experimental e terapêutica imunossupressor agents

Os aspectos imunológicos e terapêuticos da dermatopolimiosite (DPM) säo contraditórios. Os autores procuraram desenvolver miosite imunológica experimental com antígenos musculares de coelho e verificar o papel da terapêutica imunossupressora esteroídica (Prednisosna) e näo (Azatioprina). Trinta e quatro ratos subdiovididos em grupos A) Cinco animais (controle - soluçäo salina - SS); B) Dez injetados com 0,5 ml de extrato de músculo heterólogo (EMH) mais 0,5 ml de SS; C) cinco, estimulados com 0,5 ml de EMH + 0,5 ml de adjuvante completo de Freund (ACF); D) cinco animais, experimento semelhante ao grupo C + 1 mg/Kg/dia de Prednisona; E) cinco ratos, experimento homólogo ao C + 1 mg/Kg/dia de Azarioprina; F) cinco, estimulados com 0,5 ml d ACF + 0,5 ml de SS. O experimento durou sete semanas e o tecido musuclar foi analisado por hematoxilina-eosina e histoquímica. Ocorreram lesöes musculares semelhantes às encontradas na DPM humana em sete animais do grupo B. O grupo C revelou alteraçöes metabólicas musculares à histoquímica. Nos grupos tratados com imunossupressores esteroídicos e näo, as lesöes do tecido musuclar foram menos freqüentes e de pequena monta embora pertencessem ao grupo estimulados também com ACF