Características clínicas, inmunológicas y daño de órganos en pacientes con miopatías inflamatorias idiopáticas / Clinical and immunological characteristics and organ damage in patients with idiopathic inflammatory myopathies

RESUMEN Introducción: Las miopatías inflamatorias idiopáticas constituyen un grupo de enfermedades musculares caracterizadas por debilidad muscular crónica e inflamación muscular de etiología desconocida. Objetivo: Identificar las características clínicas e inmunológicas y daño de órganos en pacientes con miopatías inflamatorias idiopáticas. Método: Se realizó estudio observacional, descriptivo, transversal en 52 pacientes con diagnóstico de miopatía inflamatoria idiopática, seguidos en la consulta protocolizada de Reumatología del Hospital Clínico Quirúrgico "Hermanos Ameijeiras" entre enero 2016 y enero 2017. Para las variables cualitativas se calcularon los porcentajes de cada grupo. Se utilizó Chi-cuadrado de Pearson (Estadístico exacto de Fisher), nivel de significación del 95 % (α=0,05) para relacionar la presencia de anticuerpos y el tipo de miopatía, así como la presencia de manifestaciones clínicas de miopatías inflamatorias idiopáticas. Resultados: Del total de pacientes estudiadas, 80,8 % fueron mujeres, 61,5 % de color de piel negra, 86,5 % de procedencia urbana. La edad media al comienzo fue 42,8 ± 13,2 años, tiempo de demora al diagnóstico de 8,8 ± 7,0 meses, tiempo medio de evolución de la enfermedad de 7,5 ± 7,1 años, 80,8 % estaban en remisión, 50 % tenía anticuerpos específicos. La hipertensión arterial se encontró en 28,8 % de los pacientes y 23,1 % presentó neumonía intersticial. La artritis estuvo presente en 96,2 %, 26,9 % presentaron anticuerpos específicos Jo1 y 21,2 % Ro 52. Conclusiones: Predominaron los pacientes del sexo femenino, en la cuarta década de la vida, de procedencia urbana. Los anticuerpos específicos encontrado con más frecuencia fue el anti Jo-1, que se asoció a la presencia de neumopatía intersticial.

ABSTRACT Introduction: Idiopathic inflammatory myopathies constitute a group of muscle diseases characterized by chronic muscle weakness and muscle inflammation of unknown etiology. Objective: To identify the clinical and immunological characteristics and organ damage in patients with idiopathic inflammatory myopathies. Method: An observational, descriptive, cross-sectional study was carried out in 52 patients with diagnosis of idiopathic inflammatory myopathy, followed up in the protocolized service of Rheumatology at Hermanos Ameijeiras Clinical Surgical Hospital from January 2016 to January 2017. The qualitative variables were calculated with the percentages in each group. Pearson's Chi-square (Fisher's exact statistic) (95% significance level (α = 0.05) was used to relate the presence of antibodies and the type of myopathy as well as the presence of clinical manifestations of idiopathic inflammatory myopathies. Results: 80.8% were women of the total patients studied, 61.5% non-white skin color, 86.5% of urban origin. The mean age at the beginning was 42.8 ± 13.2 years, time delay to diagnosis was 8.8 ± 7.0 months, mean time of evolution of the disease of 7.5 ± 7.1 years. 80.8% were in remission, 50% had specific antibodies. Hypertension was found in 28.8% of the patients and 23.1% had interstitial pneumonia. Arthritis was present in 96.2%. We found 26.9% had specific Jo1 antibodies and 21.2% Ro 52. Conclusions: Urban origin female patients predominated, in their fourth decade of life, the more frequent specific antibodies found was anti Jo-1, which was associated with the presence of interstitial lung disease.

Clinical and immunological characteristics of 88 cases of overlap myositis / 北京大学学报(医学版)

OBJECTIVE@#To investigate the clinical and immunological characteristics of overlap myositis (OM) patients.@*METHODS@#The data of 368 patients with idiopathic inflammatory myopathies (IIMs) admitted to Peking University People's Hospital from January 2004 to August 2020 were analyzed retrospectively, including demographic characteristics, clinical characteristics (including fever, Gottron' s sign/papules, Heliotrope rash, V-sign, Shawl sign, Mechanic' s hands, skin ulceration, periungual erythema, subcutaneous calcinosis, dysphagia, myalgia, myasthenia, arthritis, Raynaud' s phenomenon, interstitial lung disease, pulmonary hypertension and myocardial involvement), laboratory characteristics, immunological characteristics [including antinuclear antibodies, rheumatoid factors, myositis-associated autoantibodies (MAAs) and myositis-specific autoantibodies (MSAs)] and survival. The clinical and immunological characteristics and prognostic differences of OM and non-OM were compared. The Kaplan-Meier and Log Rank methods were used to analyze the survival.@*RESULTS@#A total of 368 patients were included. 23.9% (88/368) of IIMs patients were OM patients. Among the 88 OM patients, 85.2% (75/88) of them were female, and the median interval between disease onset and diagnosis was 13.5 months. The incidence of overlapped connective tissue diseases in the OM patients was dermatomyositis (DM) in 60.2%, polymyositis (PM) in 3.4%, immune-mediated necrotizing myopathy (IMNM) in 2.3% and anti-synthetase syndrome (ASS) in 34.1%. Compared with the non-OM patients, the proportion of the females in the OM patients was higher (85.2% vs. 72.1%, P=0.016), the OM patients had longer disease duration [13.5(4.5, 48.0) months vs. 4.0(2.0, 12.0) months, P < 0.001]. As for clinical characteristics, compared with the non-OM patients, the incidence of V-sign (25.0% vs. 44.6%, P=0.001) and periungual erythema (8.0% vs. 19.6%, P=0.013) were lower; the incidence of Raynaud's phenomenon (14.8% vs. 1.8%, P < 0.001), interstitial pneumonia (88.6% vs. 72.1%, P=0.001), pulmonary hypertension (22.7% vs. 7.5%, P < 0.001) and myocardial involvement (18.2% vs. 9.3%, P=0.033) were higher. As for immunological characteristics, compared with the non-OM patients, the incidence of elevated aspartate aminotransferase (AST) (31.8% vs. 45.0%, P=0.035) was lower and elevated C-reactive protein (CRP) (58.0% vs. 44.6%, P=0.037) was higher; the positive rates of antinuclear antibodies (ANA) (85.1% vs. 63.4%, P=0.001) and rheumatoid factors (RF) (40.2% vs. 17.8%, P < 0.001) and anti-Ro-52 (71.6% vs. 56.1%, P=0.038) in serum were higher. There was no significant difference in the survival between the OM patients and non-OM patients.@*CONCLUSION@#Pulmonary hypertension and myocardial involvement were frequently observed in OM.

Correlation study on anti-Ro52 antibodies frequently co-occur with other myositis-specific and myositis-associated autoantibodies / 北京大学学报(医学版)

OBJECTIVE@#Anti-Ro52 antibodies are frequently co-occur with other myositis-specific and myositis-associated autoantibodies, we here to study this phenomenon in Chinese patients suspected with inflammatory myopathies.@*METHODS@#In the study, 1 509 patients clinically suspected with inflammatory myopathies were tested for 11 kinds of myositis-specific and myositis-associated autoantibodies (including: anti-Jo-1, PL-7, PL-12, EJ, OJ, Mi-2, SRP, Ku, PM-Scl 75, PM-Scl 100, and Ro52 antibo-dies) by line-blot immunoassay from 2010 to 2016 in Peking University First Hospital. This retrospective study was to analyze these results to reveal the characteristics of anti-Ro52 antibodies co-occuring with other myositis autoantibodies. The data were analyzed using SPSS 17.0 and Graph Pad PRISM for Chi-square test, independent t-test, Pearson's correlation analysis, and drawing statistical graphs. Significance level was set at P < 0.05.@*RESULTS@#The positive rate of anti-Ro52 antibodies was 18.3% (276/1 509 cases), which was the most frequently detected myositis antibodies in our center. 51.8% (143/276) of the patients with anti-Ro52 antibodies were combined with the other myositis antibodies, and the most common co-occurred antibodies were anti-SRP antibodies (18.8%, 52/276), and the second common co-occurred antibodies were anti-Jo-1 antibodies (13.0%, 36/276). Anti-Ro52 antibodies were the most common antibodies that co-occurred in other myositis antibodies positive patients except in anti-OJ antibodies positive group. The co-positive rate with anti-Ro52 antibodies was the lowest in anti-PM-Scl 75 positive group (30.4%, 31/102), and the highest in anti-EJ positive group (80.0%, 12/15). The positive rate of anti-Ro52 antibodies in anti-synthase antibodies (including anti-Jo-1, EJ, OJ, PL-7, and PL-12 antibodies) positive group was 57.3% (75/131), which was significantly higher than that in the other antibodies (including: anti-Mi-2, SRP, Ku, PM-Scl 75, and PM-Scl 100 antibodies) positive group with 35.2% (119/338) (χ2=18.916, P < 0.001). The intensity of anti-Jo-1, EJ, and SRP antibodies in the group of the patients that co-occurred with anti-Ro52 antibodies was significantly higher than that in the other group without anti-Ro52 antibodies respectively (P < 0.05). The intensity of anti-SRP antibodies was significantly correlated with that of anti-Ro52 antibodies (r=0.44, P=0.001).@*CONCLUSION@#Anti-Ro52 antibodies were commonly associated with other myositis-specific and myositis-associated autoantibodies, especially with anti-synthase antibodies, and the co-presence of anti-Ro52 antibodies may be correlated with the myositis antibody intensity.

Dermatomiositis idiopática asociada a fibrosis pulmonar / Idiopathic dermatomyositis associated with pulmonary fibrosis

La incidencia de la miopatía inflamatoria idiopática es de 4 a 15 casos por cada millón de habitantes y su prevalencia de 60 por cada millón de habitantes. La dermatomiositis idiopática es más frecuente en las mujeres, aunque su asociación a fibrosis pulmonar es muy rara y solo se reporta en un 2 por ciento de los casos. Se describe el caso de un paciente de 50 años de edad, femenina, que presentó debilidad a nivel de la cintura escapular acompañada de fatiga. Tenía lesiones de rascado en diferentes regiones del cuerpo por prurito y lesiones eritematosas en la piel en ambos muslos. Además, se quejaba de dolores articulares generalizados con impotencia funcional y mialgias generalizadas progresivas e hipotrofia muscular de varios grupos musculares. El estudio analítico reveló enzimas musculares elevadas. La biopsia de piel y músculo mostró elementos sugestivos de dermatomiositis. Con la espirometría se detectó trastornos ventilatorios restrictivos de grave intensidad. Mediante la radiografía de tórax se halló infiltrado difuso peribroncovascular asociado a un trayecto fibroso y la tomografía axial computarizada precisó el pulmón con consolidación alveolar y discreto engrosamiento pleural. La paciente fue tratada con prednisona a 1 mg/kg/día asociado con azatioprina 1,5 mg/kg/día. Este tratamiento fue muy eficaz, y se logró una notable recuperación clínica y por estudios de laboratorio. Reportamos el caso de una paciente con dermatomiositis idiopática y fibrosis pulmonar. Esta asociación constituye un hallazgo infrecuente en nuestro medio y más aun con el paciente asintomático(AU)

The incidence of Idiopathic Inflammatory Myopathy is from 4 to 15 cases per million inhabitants and its prevalence of 60 per million inhabitants. Idiopathic dermatomyositis is more frequent in women; Although its association with pulmonary fibrosis is described, it is very infrequent, it is only reported in 2 percent of cases. To describe a diagnosed case of idiopathic dermatomyositis and pulmonary fibrosis. A 50-year-old patient presented weakness at the level of the shoulder girdle accompanied by fatigue. Physical examination: Skin: scratching lesions in different regions of the body due to pruritus, erythematous lesions at the level of the skin on both thighs. Osteomyoarticular system: generalized joint pains with functional impotence and progressive generalized myalgias and muscular hypotrophy of several muscle groups. The analytical study revealed elevated muscle enzymes. The skin and muscle biopsy showed elements suggestive of dermatomyositis. Chest X-ray: diffuse peribronchovascular infiltrate associated with fibrous path. Spirometry: restrictive ventilatory disorders of severe intensity. Computed tomography of the lung with alveolar consolidation and discrete pleural thickening. We report the case of a patient with idiopathic dermatomyositis and pulmonary fibrosis. This association is an uncommon finding in our environment and even more so when the patient is asymptomatic(AU)

Miopatías necrotizantes autoinmunes: reconocimiento como nuevo subgrupo de miopatía inflamatoria idiopática / Autoimmune necrotizing myopathies: recognition as a new subgroup of idiopathic inflammatory myopathy

Miopatía Necrotizante Autoinmune (MNA) fue reconocida como nuevo sub-grupo de miositis luego de observar en biopsias musculares la presencia de necro-sis con escaso o ausente infiltrado inflamatorio, sumado a la expresión de dos an-ticuerpos específicos de miositis (Anticuerpo anti Partícula de Reconocimiento de Señal, anti-SRP; y Anticuerpo anti Hidroxi-3-metilglutaril-CoA reductasa, anti-HM-GCR), ambos fuertemente asociados al hallazgo histológico descrito y a fenotipos clínicos característicos a cada anticuerpo, los cuales comparten importantes simi-litudes representadas por severa debilidad muscular proximal, gran elevación de creatinkinasa (CK), escasa manifestación de síntomas y signos extramusculares, y resistencia al uso de inmunosupresión habitual. Si bien en primera instancia los criterios de clasificación propuestos estaban basados en la histología, la obser-vación de necrosis en otros subgrupos de miositis, sumado a la homogeneidad del comportamiento clínico de pacientes que expresaban anticuerpos anti-SRP o anti-HMGCR independiente de la histología presentada, llevó en el año 2016 al Grupo de Trabajo del Centro Europeo Neuromuscular (ENMC) a establecer crite-rios diagnósticos de MNA basados en el comportamiento clínico (debilidad mus-cular proximal con CK total elevada) más la presencia del anticuerpo respectivo (anti-SRP o anti-HMGCR), reservando la necesidad de realizar biopsia muscular en el caso que la serología resulte negativa, siendo así reconocidas tres entidades distintas de MNA: Miopatía anti-SRP, Miopatía anti-HMGCR y Miopatía Necroti-zante seronegativa. La presente revisión expresa el actual conocimiento de MNA y sus subtipos, refiriéndose a aspectos históricos, clínicos, histológicos, inmuno-patológicos, y de pronóstico y tratamiento.

Necrotizing autoinmune myopathy (NAM) was recognized as a new sub-group of myositis after the observation of necrosis with mild or absent inflam-matory infiltrates in muscle biopsies, in addition of expression of two specific myositis antibodies (antiSRP and antiHMGCR), which are strongly associated to the mentioned hystologic findings, with different clinical phenotypes depending on the presence of each antibody, but sharing some features like severe proximal muscle weakness, significant elevation of creatin phosphokinase (CK), mild ex-tramuscular involvement and resistance to commonly used immunosupressants. The first proposed approach to classification criteria was hystology-based, none-theless the observation of necrosis in some other types of myositis and the homo-geneity of clinical features in patients expressing antiSRP or antiHMGCR despite the hystologic findings led to a new classification scheme leaded by the European Neuromuscular Center in 2016, which recognizes thre different clinical entities of NAM, based on the antibody expression plus the presence of proximal muscle weakness, relying hystology to a secondary place thus eliminating the need for immediate biopsy to stablish a diagnosis: those are antiSRP myopathy, antiHMG-CR myopathy and seronegative necrotizing myopathy, being the last one the only needing muscle biopsy. The present review shows the actual knowledge about NAM and its subtypes, referring to hystoric, clinical, hystologic, immunopatholog-ic, prognostic and therapeutic issues.

Profil épidémiologique, clinique et valeur diagnostique des anticorps anti-Jo1 (anticorps anti-aminoacyl-t-RNA-synthétases). Etude rétrospective à propos d'une série de 22 patients

Propos : Notre objectif était de rapporter les caractéristiques épidémiologiques et cliniques de 22 patients avec anticorps anti-Jo1 positifs.Patients et méthodes : Etude rétrospective menée dans les services de Médecine interne et d'immunologie (Sfax-Tunisie) entre 2010 et 2016. Le dépistage des Anticorps Anti-Nucléaires (AAN) était réalisé par Immuno-Fluorescence Indirecte (IFI) sur cellules Hep2. Chaque sérum positif était testé par immunodot. Résultats : Vingt-deux patients ont été étudiés : 18 femmes et 4 hommes (âge moyen : 46 ans). Les principales manifestations cliniques étaient les signes rhumatologiques : 14 cas (63%), les signes généraux : 11 cas (50%), les manifestations musculaires : 8 cas (36%), les signes pleuro-pulmonaires : 8 cas (36%), les signes cutanés : 9 cas (45%), un phénomène de Raynaud : 2 cas (9%) et des mains de mécaniciens : 2 cas (9%). Le diagnostic d'une myosite de chevauchement était retenu chez 6 patients dont 4 avaient un Syndrome des Anti-Synthétases (SAS). Le diagnostic de maladies auto-immunes ou systémiques était retenu chez 9 malades. Le diagnostic de maladie non auto-immune était établi chez 7 patients. Tous les patients avaient des anti-Jo1 positifs associés avec l'anti- Ro52 (11 cas), l'anti-SSA (7 cas), l'anti-SSB (17 cas), l'anti-Sm (2 cas), l'anti-AND (1 cas), l'anti-centromère (3 cas) et l'anti Scl-70 (3 cas). Conclusion : Notre étude montre la rare prévalence des anticorps anti-Jo1, suggère l'intérêt de les rechercher devant un contexte évocateur et de façon systématique en cas de myosite ou d'atteinte pulmonaire interstitielle ou de fluorescence cytoplasmique des AAN

Papel das células dendríticas na modulação de mioblastos humanos / The role of dentritic cells in the modulation of human myoblasts

Existem diversas doenças crônico degenerativas que afetam diretamente a capacidade contrátil e força muscular da musculatura esquelética e/ou cardíaca, sejam elas doenças de cunho inflamatório ou genético. Dentre elas, podemos destacar as distrofias musculares e a miopatias inflamatórias (MI), que além da fraqueza progressiva e perda da resistência dos músculos esqueléticos, exibem importante infiltração inflamatória. A infiltração inflamatória gera danos secundários ao tecido muscular, agravando a doença com a perda da força muscular. A histopatologia do músculo lesionado é caracterizada pela presença de células inflamatórias, tais como linfócitos T, macrófagos e células dendríticas (DC). Em diversas MI, as DC são encontradas circundando fibras musculares lesionadas ou não ou mesmo invadindo fibras necróticas e não necróticas. Esta propriedade ilustra a importância da interação entre as DC e as células musculares e que exercem potencial papel na progressão das doenças musculares degenerativas. Além disso, as DC são células chave na indução da resposta imune adaptativa assim como na integração das respostas inata e específica. Entretanto a interação existente entre as DC e os mioblastos, células responsáveis pela regeneração do tecido muscular, ainda não foi claramente determinada. O objetivo desse estudo é, portanto, determinar se há interação entre as DC e mioblastos, e também que alterações morfológicas e funcionais ocorre nos mioblastos após a interaçãoPara responder o objetivo do trabalho realizamos co-cultivos in vitro de mioblastos e DC. Para tal utilizamos DC imaturas (iDC), cultivadas apenas com meio de cultura, e DC ativadas (actDC), cultivadas ativadas por LPS. Por microscopia de luz e eletrônica observamos que as iDC e actDC aderem aos mioblastos, principalmente às actDC. Nós observamos por microscopia óptica e eletrônica que as DC aderem firmemente aos mioblastos nos estágios de proliferação e diferenciação...

No estágio de diferenciação, o co-cultivo com iDC e actDC observamos que as miofibras formadas foram mais finas e desorganizadas, principalmente com actDC. [...] Entretanto no estágio de diferenciação, observamos por imunofluorescência, que a marcação para aactinina, b-catenina e laminina não foi alterada. Fato interessante foi a indoleamina 2,3 dioxigenase (IDO), uma enzima que degrada o aminoácido triptofano e promove imunotolerância foi observada marcação nos mioblastos. Quando realizamos o co-cultivo, principalmente com actDC, houve aumento na expressão de IDO nas células musculares tanto no estágio de proliferação como no de diferenciação. Analisamos que houve diminuição na capacidade de migração dos mioblastos no cocultivo com iDC e actDC, e que a diferença é pronunciada com actDC. Por fim, houve aumento na liberação de citocinas e aumento na expressão de HLA-ABC e HLA-DR no co-cultivo com actDC. Nos dados sugerem que o co-cultivo de DC e mioblastos alteram os mioblastos e que essa mudança indica uma contribuição das DC na evolução das MI...

There are several chronic degenerative diseases that are either inflammatory diseases orgenetic diseases which directly affect the contractile capacity and muscle strength in skeletal muscleand / or the heart. It is possible to highlight the muscular dystrophies and inflammatory myopathies(IM), which have clinical symptoms such as progressive weakness and loss of skeletal musclestrength and the exhibition of significant inflammatory infiltration. Inflammatory infiltrationgenerates secondary muscle tissue damage and exacerbates the progression of the disease andmuscle weakness. The sick muscle histopathology is characterized by the presence of inflammatorycells such as T lymphocytes, macrophages and dendritic cells (DC). In several IM, DC are foundsurrounding or even invading necrotic and non-necrotic muscle fibers and this facet illustrates theimportance of the interaction between the aforementioned cells and the potential in the progressionof degenerative muscle diseases. Furthermore, DC cells are key for the induction of the adaptiveimmune response as well as the integration of innate and specific responses. However theinteraction between DCs and myoblasts, the cells which are responsible for muscle tissueregeneration, has not been clearly determined. Therefore, the aim of this study is to determinewhether there is interaction between DCs and myoblasts and also any morphological and functionalchanges that occur in the myoblasts as a result of the interaction. In order to answer our question,we designed an in vitro co-culture of myoblasts plus DCs. We used immature DCs (iDC) culturedwith medium only and activated DCs (actDC) cultured with medium and LPS. We observed byoptical and electron microscopy that DCs have a tight adhesion with myoblasts in the proliferationor differentiation phases...

Upon the co-culturing of iDC and actDC in the differentiation phase, weobserved that the myofibers formed were thinner and more disorganized, especially in the actDCco-culture. [...] However, during myoblast differentiation,we observed via immunoflourescence that the staining of α-actinin, beta-catenin, and laminin wasunaltered in the different co-cultures. Interestingly, indoleamine 2,3 dioxigenase (IDO), an enzymethat degrades the essential amino acid tryptophan and promotes immune tolerance, was found to beexpressed in myoblasts. Moreover, this expression was increased during co-culture, in both theproliferation and differentiation phases. We also analyzed the myoblasts migration ability andobserved that myoblast migration is decreased during co-culture. The decrease in migration wasgreater in the actDC co-culture than the iDC. Finally, there was a greater release of cytokines andincreased expression of HLA-ABC and HLA-DR in the co-culture with actDC. In conclusion, ourdata suggests that the use of co-culture changes the myoblast profile and indicates that DCs cancontribute to IM evolution...

Miosite eosinofílica em bovinos abatidos para consumo humano / Eosinophilic myositis in cattle slaughtered for human consumption

Miosite eosinofílica é uma condição inflamatória relativamente rara que afeta os músculos estriados de bovinos e ovinos. A lesão é usualmente associada a cistos degenerados de Sarcocystis spp., principalmente S. cruzi embora esse protozoário ocorra associado às miofibras de praticamente qualquer bovino, sem provocar, na grande maioria das vezes, reação inflamatória. Esse artigo relata os achados macro e microscópicos da miosite eosinofílica em três bovinos abatidos para produção de carne para consumo humano. Macroscopicamente, as lesões consistiam de manchas ou linhas amarelo-pálidas, ocasionalmente esverdeadas, de 2-6mm no miocárdio de três bovinos e no músculo masseter de um deles. Microscopicamente, as lesões consistiam de acúmulos inflamatórios granulomatosos circundando um centro constituído por eosinófilos mortos e degenerados e ocasionais fragmentos de Sarcocystis sp. A imuno-histoquímica realizada no miocárdio de um dos bovinos com um anticorpo policlonal anti-Neospora caninum marcou cistos intactos em miofibras normais e fragmentos de cistos em meio a áreas de intensa reação inflamatória. Esse último achado corrobora a opinião dos que apontam Sarcocystis sp. como tendo participação na causa da miosite eosinofílica.

Eosinophilic myositis is a relatively rare inflammatory condition affecting striated muscle of cattle and sheep. It has been usually associated with degenerating cysts of Sarcocystis spp., mainly S. cruzi, although this protozoan occurs in the myofibers of almost every cattle without provoking an inflammatory reaction. This paper reports the gross and histopathological findings of eosinophilic myositis in three cattle slaughtered for meat production for human consumption. Grossly lesions were pale yellow, occasionally with a greenish hue, 2-6mm spots or strikes in the myocardium of the three cattle and in the masseter muscle of one of them. Microscopically there were granulomatous lesions surrounding a core of dead and degenerating eosinophils and occasional fragment components of Sarcocystis. Immunohistochemistry performed with a policlonal anti-Neospora caninum antibody in the myocardium of one of the cattle marked intact cysts in normal myofibers and intralesional fragments of disrupted cyst amidst areas with strong inflammatory reaction. This latter finding corroborates the opinion of those in favor of Sarcocystis spp. playing a role in the causation of eosinophilic myositis.

Primary tuberculous myositis: a rare clinical entity.

Summary: Primary tuberculous myositis without underlying pathology has been sparingly reported in medical literature. We report a case of primary tuberculous myositis of left upper arm in a seven-year-old boy. He presented with gradually increasing swelling on the medial aspect of the left arm. Ziehl Neelsen staining of pus collected revealed acid fast bacilli morphologically resembling Mycobacterium tuberculosis and the same was grown on the culture. Histopathological findings were consistent with tuberculosis. The results were confirmed by Genotype MTBDRpluse line probe assay. He was treated with standard four-drug regimen to which he responded well with complete resolution of the lesion.

Piomiositis tropical: Informe de 118 casos / Tropical Pyomytosis: A report of 188 Cases

Objetivo: piomiositis tropicales una infección muscular bacteriana con mayor incidencia en regiones tropicales y subtropicales, sin embargo, existen escasos reportes en México. El presente trabajo intenta caracterizar la presentación de piomiositis tropical en nuestro medio. Material y métodos: estudio descriptivo, prospectivo, de casos depiomiositis tropical manejados entre sunidades hospitalarias de segundo y tercer niveles de atención en Veracruz, México, entre agosto de 1985 y diciembre de 2000. Resultados: piomiositis tropical fue más común en menores de 40 años, con predominio en hombres, en una relación de 2.2:1. Las características principales fueron mialgias (97.5%), masa muscular fluctuante (85.6%) y fiebre (88.1 %). En más de 67% de casos hubo asociación con piodermitis y/o traumatismo muscular recientes. A su ingreso, más de 60% de casos cursaron con la fase invasiva de la enfermedad y menos de 20% presentó afectación muscular múltiple. El agente causal aislado con mayor frecuencia fue Staphylococcus aureus. Las principales complicaciones fueron las pleuropulmonares. Sólo un paciente falleció al desarrollar septicemia y falla orgánica múltiple. Conclusiones: piomiositis tropical es rara en individuos sanos; requiere de alta sospecha clínica, y en general presenta un curso favorable posterior al drenaje quirúrgico y adecuada cobertura antimicrobiana.

Objective: tropical pyomyositis, a bacterial muscular infection, has been reported frequently from tropical and subtropical zones. However, there are only a few reports from Mexico. Materials and methods: we present a prospective study of tropical pyomyositis cases in three secondary- and tertiary-care hospitals in Veracruz, Mexico between August 1985 and December 2000. Results: tropical pyomyositis was more common in young adults, male-to-female ratio being 2.2:1. Principal features were muscle pains, fluctuanct muscular mass, and fever. Tropical pyomyositis was associated with recent muscular trauma and/or pyodermitis in 67% of cases. 60% of admissions presented invasive clinical stage of the disease, and fewer of 20% of cases presented multiple muscular involvement. Staphylococcus aureus was the most common etiologic agent. Most frequent complications were pleuropulmonaries. Only one patient, who had septicemia and multiple organ failure, died. Conclusions: tropical pyomyositis is rare in healthy individuals and requires high clinical suspicion. Prognosis is generally favorable after surgical drainage and adequate antimicrobial therapy.

Clinical spectrum of inflammatory myositis in South India--a ten year study.

OBJECTIVE: To describe the clinical spectrum of inflammatory myopathies at a referral hospital in South India. METHODS: Patients were assessed for the pattern of muscle involvement, for the presence of arthritis, Raynaud's phenomenon, interstitial lung disease (ILD) and cardiac involvement. Muscle enzymes, electromyogram (EMG) and muscle biopsies were done. RESULTS: Eighty seven patients with inflammatory myopathies were encountered over 10 years. These included 24 with adult polymyositis, 26 with adult dermatomyositis, one with amyopathic dermatomyositis, five with juvenile myositis, one with dermatomysitis following carcinoma breast and 30 with overlap with other connective tissue diseases. There was a female preponderance (M:F = 1:2.35) except in juvenile myosits group (M:F = 1.5:1). The mean age of onset in years was 33.26 in adult polymyositis, 35.03 in adult dermatomyositis, 7.4 in juvenile dermatomyositis, 42 in malignancy-associated dermatomyositis and 25.51 in the overlap group. Proximal muscle weakness was seen in 98.8% patients, dysphagia in 33.3%, distal muscle weakness in 12.5%, respiratory muscle weakness in 9.2% and dysphonia in 4.6%. Other features included arthritis 35.63%, interstitial lung disease (ILD) 9.2%, Raynaud's 5.7%, myocarditis 4.6% and conduction disturbances 1.15%. Eleveated muscle enzymes were seen in 85.1% patients. Eletromyogram was positive in 66.6%. Muscle biopsy was positive in 85.29%. Anti-nuclear antibody was positive in 67.24%. All received steroids, non-responders needed methotrexate (13 patients) or azathioprine (11 patients). Death occurred in 10 (seven with dermatomyositis predominantly due to respiratory involvement and three with overlap). CONCLUSION: There was female preponderance except in juvenile myositis group. Proximal muscle weakness was the commonest feature. ILD was the commonest respiratory problem, while myocarditis was the commonest cardiac problem seen. Response to therapy and prognosis in polymyositis were good with no mortality during the study period. Death in the dermatomyositis group was mainly due to respiratory involvement.

Caracteríticas de las miopatías inflamatorias idiopáticas en la población mexicana / Idiopathic inflammatory myophaty: characteristics in the Mexican population

La mayoría de las descripciones epidemiológicas y clínicas respecto a las miopatías inflamatorias idiopáticas (MII) corresponden a población anglosajona y existen muy pocos estudios sobre las características de este grupo de padecimientos en la población mestiza mexicana. En este estudio se analizaron las características de los pacientes con diagnóstico de MII atendidos en el Servicio de Reumatología del Centro Médico Nacional 20 de Noviembre del Instituto de Seguridad y Servicio Social para Trabajadores del Estado de enero 1996 a julio de 1997. Fueron incluidos 42 pacientes con diagnóstico de MII, 34 del sexo femenino y ocho del masculino, todos de raza mestiza. La MII se clasificó como polimiositis en 12 casos, dermatomiositis en 22, juvenil en seis y asociada a otra enfermedad de tejido conectivo en dos. La edad promedio de los grupos adultos fue 33.3 años y en el grupo juvenil fue de siete años. Un gran porcentaje de pacientes (84 por ciento) refirió síntomas inespecíficos previos a la aparición de debilidad muscular o alteraciones cutáneas típicas. La evolución del padecimiento fue limitada en 15 enfermos, con exacerbaciones y remisiones en 23 y progresiva en cuatro. Se encontró mayor frecuencia de MII tipo II que lo reportado en población anglosajona, que se caracterizó además por inicio a edad temprana, evolución más agresiva y peor pronóstico en relación con los otros tipos. Del total de pacientes, sólo el 19 por ciento remitió con esteroides, el resto requirió de la adición de uno o más inmunosupresores. Se observó relación estadísticamente significativa entre el menor tiempo de evolución al iniciar el tratamiento y la obtención de remisión

Piomiositis tropical informe de 25 casos / Tropical pyomyocytis: report of 25 cases

Piomisitis tropical es una infección piógena del músculo esquelético generalmente acompañada de formación de abcesos y con mayor incidencia en regiones tropicales. Reportamos 25 casos; 15 asociados a piodermitis y/o trauma muscular recientes. En 17 casos con afectación de un solo grupo muscular, principalmente de extremidades inferiores. 10 casos correspondieron a fases, avanzadas de la enfermedad, asociándose a mayor número de complicaciones. En 11 de 18 casos, el cultivo del material obtenido por punción de abscesos, fue positivo para S aureus coagulasa positivo. 18 casos requirieron de desbridación ademas de la terapia antimicrobiana. La evolución ha sido satisfactoria en todos los casos, sin presentarse recaídas