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.

Anti-HMGCR immune-mediated necrotizing myopathy: A case report / 北京大学学报(医学版)

The patient was a 55-year-old man who was admitted to hospital with "progressive myalgia and weakness for 4 months, and exacerbated for 1 month". Four months ago, he presented with persistent shoulder girdle myalgia and elevated creatine kinase (CK) at routine physical examination, which fluctuated from 1 271 to 2 963 U/L after discontinuation of statin treatment. Progressive myalgia and weakness worsened seriously to breath-holding and profuse sweating 1 month ago. The patient was post-operative for renal cancer, had previous diabetes mellitus and coronary artery disease medical history, had a stent implanted by percutaneous coronary intervention and was on long-term medication with aspirin, atorvastatin and metoprolol. Neurological examination showed pressure pain in the scapularis and pelvic girdle muscles, and V- grade muscle strength in the proximal extremities. Strongly positive of anti-HMGCR antibody was detected. Muscle magnetic resonance imaging (MRI) T2-weighted image and short time inversion recovery sequences (STIR) showed high signals in the right vastus lateralis and semimembranosus muscles. There was a small amount of myofibrillar degeneration and necrosis, CD4 positive inflammatory cells around the vessels and among myofibrils, MHC-Ⅰ infiltration, and multifocal lamellar deposition of C5b9 in non-necrotic myofibrils of the right quadriceps muscle pathological manifestation. According to the clinical manifestation, imageological change, increased CK, blood specific anti-HMGCR antibody and biopsy pathological immune-mediated evidence, the diagnosis of anti-HMGCR immune-mediated necrotizing myopathy was unequivocal. Methylprednisolone was administrated as 48 mg daily orally, and was reduced to medication discontinuation gradually. The patient's complaint of myalgia and breathlessness completely disappeared after 2 weeks, the weakness relief with no residual clinical symptoms 2 months later. Follow-up to date, there was no myalgia or weakness with slightly increasing CK rechecked. The case was a classical anti-HMGCR-IMNM without swallowing difficulties, joint symptoms, rash, lung symptoms, gastrointestinal symptoms, heart failure and Raynaud's phenomenon. The other clinical characters of the disease included CK as mean levels >10 times of upper limit of normal, active myogenic damage in electromyography, predominant edema and steatosis of gluteus and external rotator groups in T2WI and/or STIR at advanced disease phase except axial muscles. The symptoms may occasionally improve with discontinuation of statins, but glucocorticoids are usually required, and other treatments include a variety of immunosuppressive therapies such as methotrexate, rituximab and intravenous gammaglobulin.

Miositis viral aguda en un paciente pediátrico con Covid-19: a propósito de un caso / Acute viral myositis in a pediatric patient with Covid-19: about a case

Se presenta el reporte de un caso de miositis aguda en un niño de 4 años de edad con COVID-19. El paciente manifestó fiebre y dolor en ambas pantorrillas. Con sospecha de miositis se realizó análisis de CPK, encontrando valores de 4460 UI/L. Asimismo se realizó hisopado nasofaríngeo para SARS-CoV 2, confirmando la infección. El paciente recibió hiperhidratación, presentando resolución de su cuadro clínico en menos de 5 días

This case report describes a 4 year old child with COVID-19. He presented with fever and pain in both calves. Under the suspicion of myositis a CPK analysis was performed, which showed CPK: 4460 UI/L. Nasopharyngeal RT - PCR was also performed, which was positive. As a treatment, the patient received hyperhydration, achieving full recovery after five days

Miositis por Bartonella henselae: caso clínico en una adolescente / Bartonella henselae myositis: case report in an adolescent

La miositis de origen vírico o bacteriano es frecuente en la edad pediátrica. Causa dolor muscular y debilidad, con fiebre y malestar general. Una causa es la infección por Bartonella henselae, bacteria implicada en la enfermedad por arañazo de gato que, a veces, causa afectación multisistémica. Se presenta el caso de una adolescente que acudió al servicio de urgencias por mialgia intensa, malestar, adelgazamiento y esplenomegalia. En el labortorio se observaron parámetros inflamatorios elevados. Refería contacto con un gato. Entre los estudios realizados, la resonancia magnética (RM) de miembros inferiores mostró una imagen compatible con miositis inflamatoria bilateral. En la RM abdominal, se observaron tres lesiones esplénicas no detectadas previamente y el fondo de ojo mostraba una lesión compatible con oclusión arterial retiniana o vasculitis. Se indicó tratamiento antibiótico por vía intravenosa durante 21 días con cefotaxima y cloxacilina, tras los cuales desaparecieron los signos y síntomas, aunque los reactantes inflamatorios persistieron elevados. Con base en el cuadro clínico (miositis + coriorretinitis + absceso esplénico) se pensó en una posible infección por B. henselae y se inició tratamiento oral con azitromicina y rifampicina durante 14 días. Luego del tratamiento, los valores de laboratorio fueron normales, así como la RM de control, y se constató una IgG positiva para la bacteria

Infectious myositis, whether viral or bacterial, is frequent in pediatric age. It causes muscle pain and weakness, associated with fever and general malaise. One cause is Bartonella henselae, responsible for cat scratch disease, which sometimes causes systemic symptoms. We report the case of an adolescent who came to the emergency room with intense myalgia, malaise, weight loss and splenomegaly. Blood tests showed high inflammatory markers. She had been in touch with a cat. Studies were carried out including: lower limbs MRI suggestive of bilateral inflammatory myositis, abdominal MRI with three previously undetected splenic lesions and dilated fundus examination that showed possible retinal arterial occlusion or vasculitis. After 21 days of intravenous antibiotic therapy (cefotaxime + cloxaciline), she became asymptomatic, but inflammatory markers remained high. Suspecting Bartonella henselaeinfection (myositis + chorioretinitis + splenic abscess), oral azithromycin and rifampicin were prescribed for 14 days. Blood tests and control MRI became normal, and IgG was positive.

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

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 su relación con el daño de órganos en los pacientes con miopatías inflamatorias idiopáticas. Métodos: 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 por ciento (α = 0,05) para relacionar la presencia de anticuerpos y el tipo de miopatía así como la presencia de manifestaciones clínicas de MII. Resultados: El 80,8 por ciento fueron mujeres y 86,5 por ciento 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. El 80,8 por ciento estaba en remisión, 50 por ciento tenía anticuerpos específicos. La hipertensión arterial se encontró en 28,8 por ciento de los pacientes y 23,1 por ciento presentó neumonía intersticial. La artritis estuvo presente en 96,2 por ciento. El 26,9 por ciento presentaron anticuerpos específicos Jo-1 y 21,2 por ciento Ro 52. Conclusiones: Predominaron los pacientes del sexo femenino en la cuarta década de la vida de procedencia urbana, los anticuerpos específicos encontrados más frecuentes fue el anti Jo-1, asociado a la presencia de neumopatía intersticial(AU)

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 their relationship with organ damage in patients with idiopathic inflammatory myopathies. Methods: An observational, descriptive, cross-sectional study was carried out in 52 patients with diagnosis of idiopathic inflammatory myopathy, followed in the protocolized consultation of Rheumatology at Hermanos Ameijeiras Clinical and Surgical Hospital from January 2016 to January 2017. For the qualitative variables, the percentages of each group were calculated. Pearson's Chi-square (Fisher's exact statistic) was used. 95percent 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 MII. Results: 80.8percent were women and 86.5percent 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. 80.8percent were in remission, 50percent had specific antibodies. Hypertension was found in 28.8percent of the patients and 23.1percent had interstitial pneumonia. Arthritis was present in 96.2percent. 26.9percent had specific Jo1 antibodies and 21.2percent had Ro 52. Conclusions: Urban female patients in the fourth decade of life predominated, the most frequent specific antibodies found was anti-Jo-1, associated with the presence of interstitial lung disease(AU)

Miopatía necrotizante autoinmune: Presentación de un caso clínico / Autoimmune necrotizing myositis: Presentation of a clinical case

Las miopatías inflamatorias (MI) son un grupo heterogéneo de enfermedades musculares de rara ocurrencia, caracterizadas por inflamación de los distintos componentes del tejido muscular, ya sea de forma aislada o, más comúnmente, en el contexto de una afección sistémica. Las miopatías necrotizantes inmunomediadas (MNIM) constituyen un subtipo de miopatía inflamatoria caracterizada por debilidad muscular proximal, necrosis de miofibrillas con mínimo infiltrado celular inflamatorio en la biopsia muscular e infrecuente compromiso extramuscular asociado1. Si bien existen similitudes clínicas e histopatológicas, el espectro de las miopatías inflamatorias es considerablemente variable. Por este motivo, es fundamental realizar estudios complementarios para la identificación correcta del subtipo de MI a fin de determinar su pronóstico e implementar un adecuado tratamiento. Se presenta el caso de una paciente de 29 años, sin antecedentes personales y heredofamiliares de enfermedad autoinmune ni antecedentes patológicos relevantes, que consulta a la Guardia Médica de nuestra Institución por un cuadro de dolor e impotencia funcional en los cuatro miembros, con debilidad muscular a predominio de cintura escapular y en menor medida pelviana, acompañado de astenia, tendencia al sueño e hiporreactividad.

Inflammatory myopathies (IM) or myositis are a heterogeneous group of muscle diseases of rare occurrence. Such diseases are characterized by inflammation of the different components of muscle tissue, which can occur either in isolation or, more commonly, as part of a systemic disorder. Immune-mediated necrotizing myopathies (IMNM) are a type of autoimmune myopathy characterized by proximal muscle weakness, myofiber necrosis with minimal inflammatory cell infiltrate on muscle biopsy and infrequent extramuscular involvement1. Even though there are clinical and histopathological similarities. The spectrum of inflammatory myopathies is considerably variable. Therefore, the performance of complementary studies is essential for the proper identification of the IM subtype to contribute accurately on treatment so determine the better prognosis. The present article shows the case of a young 29 years old, with no personal and family history background of autoimmune disease and no relevant pathological background. The patient consulted the medical ward of the Institution with pain, functional impairment of upper and lower extremities, muscle weakness mainly located in the pectoral girdle area and, although to a lesser degree, in the pelvic girdle area. It was also associated with asthenia, tendency to drowsiness and hyporeactivity.

Sarcoid-like granulomatous myositis-associated hypercalcemia. An infrequent case to consider / Hipercalcemia asociada a miositis granulomatosa sarcoidea simil- sarcoidea. Un caso infrecuente a considerar

Abstract PTH-independent hypercalcemia due to granulomatous disease is well-documented and sarcoidosis is the most characteristic disease, although there are others. We describe a case of sarcoid-like granulomatous myositis. An 87-year-old man was referred with tetraparesis and hypercalcemia (albumin-corrected calcium of 13.4 mg/dl) following a trip to the Caribbean. The evaluation showed a suppressed PTH, 25-hydroxy vitamin D of 7.5 ng/ml, 18F-FDG PET/CT showed markedly increased uptake in intercostal, back, shoulder, but tock and thigh muscles and a deltoid biopsy confirmed extensive granulomatous myositis. He was prescribed glucocorticoids which resulted in normalized plasma calcium levels and complete recovery from tetraparesis. Sarcoid-like granulomatous myositis should be incorporated into the differential diagnosis of PTH-independent hypercalcemia, especially in the absence of clinical features of sarcoidosis and with special emphasis on the use of 18F-FDG PET/CT to ensure a correct approach.

Resumen La hipercalcemia PTH-independiente asociada a enfermedades granulomatosas está bien documentada y la sarcoidosis es la enfermedad más característica, a pesar de que existen otras. Des cribimos un caso de miositis granulomatosa simil-sarcoidea. Un hombre de 87 años consultó por tetraparesia e hipercalcemia (calcio corregido por albúmina 13.4 mg/dl) luego de un viaje al Caribe. La evaluación mostró una PTH suprimida, 25-hidroxivitamina D 7.5 ng/ml, 18F-FDG PET/CT mostró marcado aumento de captación a nivel de musculatura intercostal, dorsal, deltoidea, glúteos y muslos. Una biopsia deltoidea confirmó una miositis granulomatosa extensa. Se prescribieron glucocorticoides, resultando en normalización del calcio plasmático y completa recuperación de la tetraparesia. La miositis granulomatosa simil-sarcoidea debe ser incorporada den tro del diagnóstico diferencial de la hipercalcemia PTH-independiente, especialmente en ausencia de hallazgos clínicos de sarcoidosis y con especial énfasis en el uso de 18F-FDG PET/CT para su correcta aproximación.

Clinical and immunological characteristics of patients with anti-synthetase syndrome complicated with cardiac involvement / 北京大学学报(医学版)

OBJECTIVE@#To investigate the clinical and immunological features of cardiac involvement in patients with anti-synthetase syndrome (ASS).@*METHODS@#In the study, 96 patients diagnosed with ASS hospitalized in the Department of Rheumatology and Immunology, Peking University People's Hospital from April 2003 to November 2020 were included. The patients were divided into two groups according to whether they were accompanied with cardiac involvement. Demographic features, clinical characteristics (Gottron's sign/papules, muscle damage, etc.), comorbidities, laboratory indices (creatine kinase, inflammatory indicators, immunoglobulin, complement, lymphocyte subset, autoantibodies, etc.) were collected and the differences between the two groups were analyzed statistically.@*RESULTS@#The prevalence of cardiac involvement in the patients with ASS was 25.0% (24/96). The ASS patients complicated with cardiac involvement presented with elevated cardiac troponin I (cTnI, 75.0%, 18/24), pericardial effusion (33.3%, 8/24), reduction of left ventricular function (33.3%, 8/24) and valves regurgitation (33.3%, 8/24). The age of onset of the patients with cardiac involvement was older than that of the patients without cardiac involvement [(54.58±10.58) years vs. (48.47±13.22) years, P=0.043). Arthritis was observed less frequently in the patients with cardiac involvement than those without cardiac involvement (37.5% vs. 61.1%, P=0.044). In addition, rapidly progressive interstitial lung disease (54.2% vs. 30.6%, P=0.037) was observed more frequently in the patients with cardiac involvement than those without cardiac involvement. As compared with the ASS patients without cardiac involvement, C-reactive protein (CRP) [(13.55 (8.96, 38.35) mg/L vs. 4.60 (1.37, 17.40) mg/L, P=0.001], and lactate dehydrogenase (LDH) [408.0 (255.0, 587.0) U/L vs. 259.5 (189.8, 393.8) U/L, P=0.007] were significantly higher in the patients with cardiac involvement. Anti-Ro-52 antibody was detected more commonly in the ASS patients with cardiac involvement compared with the patients without cardiac involvement (91.7% vs. 69.4%, P=0.029). No significant differences were found in the comorbidities, alanine transaminase (ALT), aspartate transaminase (AST), creatine kinase (CK), erythrocyte sedimentation rate (ESR), ferritin (Fer), immunoglobulin G (IgG), complement 3 (C3), complement 4 (C4), lymphocyte subset between the two groups.@*CONCLUSION@#Cardiac involvement is common in ASS, mainly manifested as myocardial damage. It is necessary to be aware of cardiac complications in patients with elevated CRP, elevated LDH and positive anti-Ro-52 antibody.

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.

Neumonía y miositis aguda benigna de la infancia por Mycoplasma pneumoniae asociado a encefalitis: reporte de caso / Pneumonia and benign acute myositis of childhood due to Mycoplasma pneu-moniae associated with encephalitis: a case report

Una de las principales causas de neumonía en niños entre 5 y 15 años es el Mycoplasma pneumoniae, una bacteria que causa manifestaciones clínicas atípicas como la miositis y encefalitis. Reportamos un caso de una niña de cinco años que presentó limitación funcional en extremidades inferiores precedida por una infección respiratoria superior. Posteriormente, se complicó con neumonía y encefalitis. Se administraron antibióticos y antivirales debido al deterioro clínico del paciente. La serología de inmunoglobulinas para Mycoplasma pneumoniae fue positiva; mientras que los demás estudios virales fueron negativos. El curso clínico fue favorable con disminución progresiva de la dificultad respiratoria, trastorno del sensorio y mejoría en la limitación funcional en las extremidades inferiores a los 15 días de tratamiento.

One of the leading causes of pneumonia in children between 5 to 15 years is Mycoplasma pneumoniae, a bacterium that causes atypical clinical manifestations such as myositis and encephalitis. We report a 5-year-old girl who presented functional limitations of the lower extremities preceded by an upper respiratory infection. Later on, she developed pneumonia and encephalitis. Antibiotics and antivirals were administered due to the clinical deterioration of the patient. IgM serology for Mycoplasma pneumoniae was positive, while the other viral studies were negative. The clinical course was favorable with a progressive decrease in respiratory distress, sensorial disorder, and improvement in the functional limitations of the lower limbs after 15 days of treatment.

Miositis viral, reporte de un caso pediátrico / Viral myositis, a pediatric case report

La miositis viral aguda es una complicación posterior a una infección viral causada, principalmente, por virus influenza A y B. Se caracteriza por ser un proceso inflamatorio transitorio, súbito, autolimitado y benigno. Generalmente, afecta a niños preescolares y escolares, que presentan dolor bilateral y sensibilidad en los grupos musculares de los miembros inferiores sin alteración en el examen neurológico. Puede generar alteración de la marcha o de la bipedestación. Su principal complicación es la rabdomiólisis, por lo que se debe hacer un seguimiento clínico y de los valores de la creatinfosfoquinasa. Se presenta el caso de un niño en edad escolar con diagnóstico de miositis viral aguda. Debido a que es poco frecuente y su incidencia en Latinoamérica es desconocida, se considera importante el reporte del caso y la revisión del tema, ya que su curso es benigno, de fácil manejo, y su conocimiento evita estudios y hospitalizaciones innecesarias.

Acute viral myositis is a complication after a viral infection mainly caused by Influenza A and B viruses. It is characterized as a transitory, sudden, self-limiting and benign inflammatory process. It usually affects preschool and school children presenting bilateral pain and sensitivity in the muscle groups of the lower limbs without alteration in the neurological examination. It can affect the gait or standing. The main complication is rhabdomyolysis, which is why clinical followup and values of creatine phosphokinase must be done. We present the case of a school-age child diagnosed with acute viral myositis. Because it is not a frequent entity and its incidence in Latin America is unknown, we consider important to report the case and review the topic, as its clinical course is benign, easily treated, and its knowledge can avoid unnecessary studies and hospitalizations.

Autoanticuerpos en miopatías inflamatorias idiopáticas: enfoque en la práctica clínica / Autoantibodies in idiopathic inflammatory myopathies: focus on clinical practice

Las miopatías inflamatorias idiopáticas (MII) conforman un grupo diverso de en-fermedades caracterizadas por lesiones musculares inmunomediadas, que pue-den estar acompañadas de manifestaciones extramusculares.La identificación de autoanticuerpos específicos de miositis (AEM) y asociados a miositis (AAM) se ha convertido en una herramienta relevante en el diagnóstico, clasificación y pronóstico en este grupo de enfermedades.Adquieren relevancia en el diagnóstico y determinación de pronóstico de la Enfer-medad Pulmonar Intersticial (EPI), en el diagnóstico diferencial entre subgrupos de MII, especialmente en entidades de comportamiento atípico como la Miopatía Necrotizante Inmuno Mediada (MNIM) y la Miositis por Cuerpos de Inclusión, y permiten el enfoque y seguimiento estricto en pacientes con autoanticuerpos asociados a cáncer. En el último tiempo se ha planteado su utilidad tanto en la determinación de actividad de la enfermedad como en predecir la respuesta al tratamiento inmu-nosupresor.

Idiopathic inflammatory myopathies (IIM) comprise a heterogenous group of ill-nesses characterized by immune mediated muscular injuries that may be accom-panied by extra-muscular manifestations.The identification of myositis-specific autoantibodies MSAs and myositis-associ-ated autoantibodies (MAA) has become a relevant tool in the diagnose, classifica-tion, and prognosis in this group of illnesses.They become relevant in the diagnose and determination of a prognosis for Inter-stitial Lung Disease (ILD), in the differentiated diagnose among sub-groups of MII, especially in entities of an atypical behavior, such as Immune Mediated Necrotiz-ing Myopathy (IMNM) and Inclusion Body Myositis, and they enable a strict focus and follow-up on patients with cancer-associated autoantibodies. Lately, its usefulness has been stated both to determine disease activity and to forecast the response to the immunosuppressive treatment.

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

Three cases of anti-TNF induced myositis and literature review / Três casos de miosite induzida pelo anti-TNF e revisão da literatura

Abstract Anti-tumor necrosis factor drugs are frequently preferred in the treatment of rheumatologic diseases and other inflammatory diseases. The development of myositis after using anti-tumor necrosis factor drugs is a rare clinical condition. Here we aimed to report cases who developed myositis after using anti-tumor necrosis factor drugs and review the current literature. We report two cases of rheumatoid arthritis and a case of ankylosing spondylitis developed idiopathic inflammatory myopathy following anti-tumor necrosis factor therapy. In conclusion, myositis could develop during anti-tumor necrosis factor therapy, so these patients should be evaluated carefully initially for myositis and should be closely monitored due to the potential for developing myositis in treatment process.

Resumo Os fármacos antifator de necrose tumoral (anti-TNF) são frequentemente preferidos no tratamento de doenças reumatológicas e outras doenças inflamatórias. O desenvolvimento de miosite após o uso de anti-FNT é uma condição clínica rara. Este estudo objetivou descrever casos de pacientes que desenvolveram miosite após o uso de anti-TNF e fazer uma revisão da literatura atual. Descrevem-se dois casos de artrite reumatoide (AR) e um caso de espondilite anquilosante (EA) que desenvolveram miopatia inflamatória idiopática após o tratamento com anti-TNF. Em conclusão, pode haver desenvolvimento de miosite durante o tratamento com anti-TNF, de modo que esses pacientes devem ser cuidadosamente avaliados inicialmente à procura de miosite e devem ser cuidadosamente monitorados em razão do potencial de desenvolvimento de miosite no processo de tratamento

Miositis aguda benigna de la infancia: Serie clínica y revisión de la literatura / Benign acute childhood myositis: Clinical series and literature review

La miositis aguda benigna de la infancia (MABI) es una entidad clínica autolimitada, infrecuente, que afecta a niños en edad preescolar y escolar. Dada su asociación a cuadros virales, se sugiere una relación con este tipo de agentes, entre los que predomina el virus influenza. OBJETIVO: Describir un brote de casos de MABI presentados en un servicio pediátrico. PACIENTES Y MÉTODO: Serie clínica retrospectiva de pacientes que consultaron por un cuadro clínico compatible con MABI en el período agosto-noviembre de 2012, en el Servicio de Urgencia pediátrico de un centro asistencial. RESULTADOS: Se presentan una serie de 9 niños, edades entre 4 y 12 años, con un pródromo de fiebre asociado a síntomas respiratorios, seguido de dolor agudo intenso de ambas pantorrillas y claudicación. En los exámenes de laboratorio destacaba un alza de creatincinasa, con un valor promedio de 4.066 UI/L. El estudio etiológico evidenció influenza B en 3 pacientes y Mycoplasma pneumoniae en uno. El manejo consistió en hidratación y antiinflamatorios no esteroidales, con favorable evolución clínica y de laboratorio. CONCLUSIONES: La MABI es una entidad benigna, autolimitada, de excelente pronóstico, con una presentación clínica que en la mayoría de los casos requiere manejo ambulatorio. Deben evitarse estudios invasivos y hospitalizaciones innecesarias.

Benign acute childhood myositis (BACM) is a rare clinical condition that mainly affects pre-school and school age-children. It is usually preceded by a viral illness, particularly influenza virus infection. OBJECTIVE: To describe a cluster of BACM cases that were seen in a paediatric unit. PATIENTS AND METHODS: A retrospective series of cases that presented with a clinical picture suggestive of BACM between August and November 2012 in the paediatric emergency department of a private clinic. RESULTS: Nine children, between 4 and 12 years, presented with a history of a recent febrile upper viral respiratory infection, followed by intense calf pain and claudication. They all recovered without complications. Laboratory results showed a marked increase in CK, with a mean of 4,066 IU/l. Three of the cases had influenza B infection and one Mycoplasma pneumonia infection. They were managed conservatively with hydration and non-steroidal anti-inflammatory drugs. CONCLUSIONS: BACM is a benign entity with a characteristic clinical presentation that can be managed most of the time in the ambulatory setting, avoiding invasive studies and unnecessary hospital admission.

Syndrome in question: antisynthetase syndrome (anti-PL-7)

Abstract: Antisynthetase syndrome is a rare autoimmune disease characterized by interstitial lung disease and/or inflammatory myositis, with positive antisynthetase antibodies (anti-Jo-1, anti-PL-7, anti-PL-12, ZO, OJ, anti-KE or KS). Other symptoms described include: non-erosive arthritis, fever, Raynaud's phenomenon, and "mechanic's hands." The first therapeutic option is corticotherapy, followed by other immunosuppressants. The prognosis of the disease is quite limited when compared to other inflammatory myopathies with negative antisynthetase antibodies.

Clinical and laboratory description of a series of cases of acute viral myositis / Descrição clínico-laboratorial de uma série de casos de Miosite Aguda Viral

ABSTRACT OBJECTIVE: Describe the clinical and laboratory profile, follow-up, and outcome of a series of cases of acute viral myositis. METHOD: A retrospective analysis of suspected cases under observation in the emergency department was performed, including outpatient follow-up with the recording of respiratory infection and musculoskeletal symptoms, measurement of muscle enzymes, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), transaminases (AST and ALT), blood count, C-reactive protein, and erythrocyte sedimentation rate in the acute phase and during follow-up until normalization. RESULTS: Between 2000 and 2009, 42 suspected cases were identified and 35 (27 boys) were included. The median age was 7 years and the diagnosis was reported in 89% in the first emergency visit. The observed respiratory symptoms were cough (31%), rhinorrhea (23%), and fever (63%), with a mean duration of 4.3 days. Musculoskeletal symptoms were localized pain in the calves (80%), limited ambulation (57%), gait abnormality (40%), and muscle weakness in the lower limbs (71%), with a mean duration of 3.6 days. There was significant increase in CPK enzymes (5507 ± 9180 U/L), LDH (827 ± 598 U/L), and AST (199 ± 245 U/L), with a tendency to leukopenia (4590 ± 1420) leukocytes/mm3. The complete recovery of laboratory parameters was observed in 30 days (median), and laboratory and clinical recurrence was documented in one case after 10 months. CONCLUSION: Typical symptoms with increased muscle enzymes after diagnosis of influenza and self-limited course of the disease were the clues to the diagnosis. The increase in muscle enzymes indicate transient myotropic activity related to seasonal influenza, which should be considered, regardless of the viral identification, possibly associated with influenza virus or other respiratory viruses.

RESUMO OBJETIVO: Descrever o perfil clínico-laboratorial, o acompanhamento e o desfecho de uma série de casos de miosite aguda viral. MÉTODO: Foi conduzida uma análise retrospectiva de casos suspeitos, em observação em unidade de emergência, e seguimento ambulatorial com o registro de sintomas de infecção respiratória, sintomas músculo-esqueléticos, determinação de enzimas musculares, creatina-fosfoquinase (CPK), desidrogenase lática (DHL), transaminases (AST e ALT), hemograma, proteína C reativa e velocidade de hemossedimentação, na fase aguda e no acompanhamento, até a normalização. RESULTADOS: Entre 2000 e 2009, 42 casos suspeitos foram identificados e 35 (27 meninos) foram incluídos. A mediana de idade foi de sete anos e o diagnóstico relatado em 89%, na primeira visita de emergência. Os sintomas respiratórios observados foram: tosse (31%), coriza (23%) e febre (63%), com duração média de 4,3 dias. Os sintomas músculo-esqueléticos foram: dor localizada nas panturrilhas (80%), deambulação limitada (57%), marcha anormal (40%) e fraqueza muscular nos membros inferiores (71%), com duração média de 3,6 dias. Observou-se elevação importante das enzimas CPK (5.507 ± 9.180) U/l, DHL (827 ± 598) U/l e AST (199 ± 245) U/l e tendência a leucopenia (4.590 ± 1.420) leucócitos/mm3. A recuperação completa dos parâmetros laboratoriais foi observada em 30 dias (mediana) e a recaída clínica e laboratorial em um caso após 10 meses. CONCLUSÃO: Os sintomas típicos com enzimas musculares elevadas após diagnóstico de influenza e o curso autolimitado foram os indícios para o diagnóstico. A elevação de enzimas musculares indica a atividade miotrópica transitória relacionada à influenza sazonal que deve ser considerada, a despeito da identificação viral, possivelmente associada com o vírus influenza ou outros vírus respiratórios.

Síndrome Antissintetase: relato de dois casos e revisão da literatura / Antisynthetase Syndrome: two case reports and literature review

A Síndrome Antissintetase (SAS) é caracterizada por miosite, fenômeno de Raynaud, febre, doença pulmonar intersticial, artropatia e mãos de mecânico associados à presença de anticorpos contra a sintetase do RNAt especialmente anti-Jo-1. Este artigo tem como objetivo revisar a literatura sobre SAS e relatar dois casos, sendo o caso 1 de uma paciente com Polimiosite que desenvolveu, após alguns anos de doença, subluxação da articulação interfalangeana proximal do primeiro quirododáctilo direito, associada a manifestações pulmonares e anti-Jo-1 positivo. O caso 2 é de uma paciente com Dermatomiosite que evoluiu com subluxação dos dois primeiros quirodáctilos, anti-Jo-1 positivo e alterações pulmonares intersticiais na TC de tórax, porém assintomática. Esses casos demonstram a importância do diagnóstico precoce. Os autores descrevem dois casos dessa síndrome rara, enfatizando a sua gravidade do ponto de vista pulmonar e articular.

Antisynthetase Syndrome (ASS) is characterized by myositis, Raynaud's phenomenon, fever, interstitial lung disease, mechanic's hands and arthropathy associated with the presence of antibodies against tRNA synthetase, especially anti-Jo-1. This article aims to review the literature on ASS and report two cases where the first is a patient with polymyositis who developed subluxation on the proximal interphalangeal joint of bilateral first right finger after a few years of the disease, associated with pulmonary manifestations and positive anti-JO-1. In the second case, we present a patient with dermatomyositis, who developed a subluxation of the two first fingers, anti-Jo1 positive and chest CT changes, but without clinical evidence of pulmonary involvement. These cases reveal the importance of performing early diagnosis. The authors describe two cases of this rare syndrome, emphasizing the severity of interstitial lung disease and arthritis.

Benign acute childhood myositis in the eastern region of Kingdom of Saudi Arabia; a 5-year experience

To assess the epidemiological, clinical and laboratory characteristics, and outcomes of BACM in children diagnosed at a teaching hospital in the eastern province of the KSA. A retrospective study of 28 patients admitted to the hospital with the diagnosis of BACM was carried out at King Fahd Hospital of the University, AlKhobar, Kingdom of Saudi Arabia [KSA], from January 2008 to December 2012. Demographics, clinical characteristics, laboratory findings and patients' responses were analyzed. Thirty episodes were reported over 5 years with incidence of 3.17 per 100,000. The male to female ratio was 6:1. The mean age was 6 years. A seasonal peak during the winter months was observed. The major symptoms were fever, inability to walk in all the patients [100%] and symptoms of upper respiratory tract infections found in 70%. Major clinical findings were the normal deep tendon reflex and calf muscle tenderness in 76.6% and 100% respectively. The prominent laboratory findings were the high creatine phosphokinase [CPK] and leukopenia in 100% and 60%, respectively. Our findings showed that the clinical and epidemiological features associated with BACM, in the KSA, have the similar pattern of other studies from different regions in the world. A nationwide survey, however, is necessary to investigate the overall incidence, risk factors and the outcome of BACM in the KSA