Endothelial lesion and complement activation in patients with Scleroderma Renal Crisis / Lesão endotelial e ativação do complemento em pacientes com crise renal esclerodérmica

Abstract In kidney biopsies reviews, scleroderma renal crisis (SRC) is characterized by vascular endothelial injuries, C4d deposits on peritubular vessels, and acute and chronic injuries coexisting on the same biopsy. The clinical signs of thrombotic microangiopathy (TMA) are described in systemic sclerosis (SSc), nevertheless, it has not been related to acute injuries described on kidney biopsies. We report a case of SRC in a patient with scleroderma-dermatomyositis overlap syndrome, which also showed clinical and histopathological data of TMA. On fundus examination, a severe acute hypertensive retinopathy was found. The kidney biopsy showed severe endothelial damage with widening of mucoid cells at the level of the intima, focal concentric proliferation on most small arterioles, and C3, C4d, and IgM deposits along the capillary walls. The genetic study of complement only showed the presence of membrane cofactor protein (MCP) risk haplotypes, without other genetic complement disorders. We understand that in a patient with TMA and SSc, the kidney damage would be fundamentally endothelial and of an acute type; moreover, we would observe clear evidence of complement activation. Once further studies correlate clinical-analytical data with anatomopathological studies, it is likely that we will be forced to redefine the SRC concept, focusing on the relationship between acute endothelial damage and complement activation.

Resumo Nas revisões de biópsias renais, a crise renal esclerodérmica (CRE) é caracterizada por lesões endoteliais vasculares, depósitos de C4d em vasos peritubulares e lesões agudas e crônicas que coexistem na mesma biópsia. Os sinais clínicos de microangiopatia trombótica (MAT) são descritos na esclerose sistêmica (ES); no entanto, não foram relacionados às lesões agudas descritas nas biópsias renais. Relatamos um caso de CRE em um paciente com síndrome de superposição de esclerodermia-dermatomiosite, que também apresentou dados clínicos e histopatológicos de MAT. No exame de fundo do olho, foi encontrada uma retinopatia hipertensiva aguda grave. A biópsia renal mostrou lesão endotelial grave com alargamento das células mucoides ao nível da íntima, proliferação concêntrica focal na maioria das pequenas arteríolas e depósitos de C3, C4d e IgM ao longo das paredes dos capilares. O estudo genético do complemento mostrou apenas a presença de haplótipos de risco da proteína cofator de membrana (PCM), sem outros distúrbios genéticos do complemento. Entendemos que em um paciente com MAT e ES, o dano renal seria fundamentalmente endotelial e do tipo agudo; além disso, observaríamos evidências claras de ativação do complemento. Uma vez que novos estudos correlacionam dados clínico-analíticos com estudos anatomopatológicos, é provável que sejamos forçados a redefinir o conceito de CRE, enfocando a relação entre dano endotelial agudo e ativação do complemento.

Dermatomiositis asociada al autoanticuerpo anti-MDA5 / Dermatomyositis associated with anti-MDA5 autoantibody

La dematomiositis es una miopatía inflamatoria idiopática con espectro clínico variable. En los últimos años se ha identificado un número de autoanticuerpos específicos de miositis útiles para el diagnóstico, la clasificación y el pronóstico de las diversas formas de la enfermedad, entre los que se encuentra el anti-MDA5. Este anticuerpo se asocia al desarrollo de úlceras cutáneas, enfermedad intersticial pulmonar rápidamente progresiva, mortalidad temprana y mal pronóstico por lo que la detección del mismo, en un contexto clínico adecuado, plantea la necesidad de un tratamiento inmunosupresor agresivo. Describimos un caso de dermatomiositis hipomiopática, (es decir, con afección muscular leve) que presentaba compromiso cutáneo específico, enfermedad pulmonar intersticial y anticuerpo anti-MDA5 que respondió favorablemente al tratamiento combinado con ciclofosfamida, gamaglobulina y corticoides.

Dematomyositis is an idiopathic inflammatory myopathy with a variable clinical spectrum. In recent years, a number of myositis-specific antibodies have been identified including anti-MDA5, which is us eful for diagnosis, prognosis and classification of the diverse clinical forms of the disease. This antibody is associated with cutaneous ulcers, rapidly progressive interstitial lung disease, early mortality and poor prognosis, so the detection of this antibody in a suitable clinical context, raises the need for an aggressive immunosuppressive treatment. We describe a case of dermatomyositis classified as hypomyopathic (i.e. involving mild muscle weakness), presenting specific skin lesions, interstitial lung disease, and presence of anti-MDA5 antibody that had a favorable response to combined treatment with cyclophosphamide, gamma globulin and corticosteroids.

Prevalence and reactivity of anti-melanoma differentiation-associated gene 5 (anti-MDA-5) autoantibody in Brazilian patients with dermatomyositis

Abstract: Background: There have been no studies to date on the frequency and reactivity of aanti-melanoma differentiation-associated gene 5 (anti-MDA-5) in samples from the Brazilian population with dermatomyositis. Objectives: To analyze this autoantibody in the Brazilian population. Methods: This was a single-center cross-sectional study in which 131 consecutive adult patients (109 dermatomyositis and 22 clinically amyopathic dermatomyositis) with active disease were evaluated from 2000 to 2016. Analysis of the anti-MDA-5 autoantibody was performed by ELISA. Results: The presence of this autoantibody was observed in 14.7% and 22.7% of patients with dermatomyositis and clinically amyopathic dermatomyositis, respectively. In the case of dermatomyositis, the autoantibody was associated less frequently with Raynaud's phenomenon and periungual hyperemia (P<0.05). In clinically amyopathic dermatomyositis, the presence of this autoantibody was not associated statistically with any demographic, clinical, laboratory, or imaging characteristics. Study limitations: The cross-sectional study design did not allow establishing a temporal correlation between anti-MDA-5 autoantibody and various study variables. In addition, pulmonary function tests were not performed in the patients. Conclusions: The frequency of anti-MDA-5 autoantibody was comparable to that of other populations with dermatomyositis, but with a different reactivity than described in the literature. In addition, there was a phenotypic variability between our patients with clinically amyopathic dermatomyositis and those described in the literature. Further studies are needed to confirm the current study's findings and elucidate this autoantibody's reactivity in Brazilians with idiopathic inflammatory myopathies.

Autoantibodies in adult patients with idiopathic inflammatory myopathies in Buenos Aires

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

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

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

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

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

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. .

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

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

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

Differential Immunohistological Features of Inflammatory Myopathies and Dysferlinopathy

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

Myositis in mixed connective tissue disease: a unique syndrome characterized by immunohistopathologic elements of both polymyositis and dermatomyositis

OBJETIVO: Caracterizar as células do infiltrado inflamatório, o padrão de expressão das moléculas de adesão (ICAM-1 e VCAM-1), complexo de ataque à membrana (C5b-9) e antígenos de histocompatibilidade maior (MHC) em biópsias musculares de patientes com doença mista do tecido conectivo (DMTC). MÉTODO: Foram estudados14 pacientes com DMTC e comparadas com 8 pacientes com polimiosite (PM), 5 com dermatomiosite (DM) e 4 com distrofias. As células inflamatórias foram caracterizadas como CD4+, CD8+, células T de memória (CD45RO+) e virgens, células "natural killer" e macrófagos. As expressões de MHC-I e ûII, ICAM-1, VCAM-1 e C5b-9 foram caracterizadas em fibras musculares e vasos. RESULTADOS:A análise morfológica demonstrou um padrão tipo PM. O estudo imuno-histoquímico revelou diminuição do número de capilares, predomínio de células CD4+ e B nas regiões perivasculares e predomínio de CD8+ e CD45RO+ nas regiões endomisiais. A expressão de MHC-I nos vasos e nas fibras degeneradas, MHC-II nos vasos e fibras perifasciculares e expressão de ICAM-1 / VCAM-1 no endotélio indicaram uma associação de processos vascular e imune-celular mediando a lesão muscular. CONCLUSAO: Os achados revelaram duplo mecanismo na DMTC, imune-celular como na PM e vascular como na DM.

Diseases associated with the different patterns of antinuclear antibodies detected by immunofluorescence

immunofluorescent antinuclear antibody [ANA] patterns are variable and may indicate specificity towards certain diagnosis. to explore the spectrum of diseases associated with the common different ANA patterns seen at King Abdulaziz University Hospital [KAUH]. ANA tests were performed by indirect immunofluorescent assay [IIFA] in the clinical immunology laboratory. Cases with positive ANA cases were selected sequentially. Their IIFA patterns and patient files were reviewed. 211 positive ANA cases were studied. The ages ranged between 3-70 years [mean age 31.4 +/- 15] females predominated [83%]. Rheumatological disorders were the predominant illnesses; they were diagnosed in 148 cases [70.1%]. These included systemic lupus erythematosus [SLE] 71 [33.6%], rheumatoid arthritis 18 [8.5%], others 26 [12.3%], and undiagnosed 33 [15.6%]. Other autoimmune disorders followed with 34 [16.1%]. There were also 23 [10.9%] cases with recurrent abortion and 6 [2.8%] with miscellaneous illnesses. The different ANA patterns on IIFA were: homogeneous 107 [50.7%], speckled 68 [32.2%], nuclear 18 [8.5%], peripheral 7 [3.3%], centromere 1 [0.5%], and mixed 10 [4.7%]. A highly significant association was detected between the peripheral ANA pattern and SLE cases [P<0.01]. autoimmune disorders, particularly rheumatological, were the commonest diseases associated with positive ANA test. The predominant ANA pattern was the homogeneous, followed by the speckled which is compatible with reports in the literature. ANA staining pattern have limited value in the clinical assessment of autoimmune diseases; however, ANA has very high sensitivity for SLE especially in cases with peripheral ANA pattern

Immunohistochemical study of skin biopsies in dermatomyositis

In the present study,6 monoclonal anitbodies were used to determine the cellular composition of skin infiltrates eta affected and clinically uninvolved skin of patients with dermatomyositis The majority of cells detected in the lesional infiltrate were T-lymphocytes, especially T-helper and,macrophages. B-cells were almost absent lesional epidermal Langerhans cells' density was not different from normal skin, but cells were less dendritic and showed irregular distribution in lesional skin. These findings are different from dermatomyositis muscle infiltrate but are similar to those detected in skin affected by cutaneous lupus erythematosus In autoimmune diseases,cellular infiltrates may be more organ-specific than disease-specific

Inflammatory myopathies--a clinicopathologic study.

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

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

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

Dermatomiositis del niño: estudio inmunológico / Childhool dermatomyositis: immunologic study

Estudiamos 8 niños con dermatomiositis con el objeto de detectar las anormalidades inmunológicas relacionadas al padecimiento. Las inmunoglobulinas séridas IgG, IgM e IgA, fueron determinadas por nefelometría, resultando normales en todos los casos, excepto en 2 enfermos, en quienes se notó un ligero incremento sin relación con la fase de actividad de la enfermedad. Sólo un paciente tuvo descenso de C4 asocaido a miopatía activa, pero no con vasculitis. No detectamos hipogamaglobulinemia y la prueba de VDRL fue negativa en todos los niños. El factor reumatoide fue positivo en 4 casos con títulos menores de 1:80 por la técnica de Waaler Rose. Los anticuerpos antinucleares por inmunofluorescencia indirecta estuvieron presentes en 5 niños, predominando el patrón moteado, resultados que no tuvieron relación con la exacerbación del padecimiento. No hubo anticuerpos anti-DNAn, o contra antígenos nucleares extraibles. Los anticuerpos anti-Jo-1, Mi-1 y Mi-2 fueron negativos. Los anticuerpos anti-toxoplasma de la clase IgG por la prueba de inmunofluorescencia indirecta estuvieron presentes en 7 pacientes. En ningún caso de encontró historia de toxoplasmosis ni datos de este padecimiento al momento del estudio o durante el seguimiento. Los anticuerpos anti-músculo liso fueron positivos en un caso. Ninguna de estas anormalidades mostró correlación con la actividad del padecimiento.

Dermatomiositis en la infancia: revisión clínico- terapéutica / Infantile dermatomyositis: clinical-therapeutic review

Es una enfermedad del colágeno que afecta la piel y los músculos, considerándose como forma infantil a la que se presenta antes de los 15 años. Su relación con el sexo es de tres mujeres por un varón. No es exclusiva de la raza blanca. La evolución pude ser aguda o crónica. Sus características distintivas con respecto de la forma del adulto son: 1) se asocia con calcificaciones del tejido celular subcutáneo, la piel y los músculos; 2) no tiene relación con neoplasias; 3) presencia de vasculitis necrotizante de los pequeños vasos. Existen signos cutáneos y musculares. En la piel están representados por el eritema facial característico: periorbitario, heliotropo, con edema. El eritema está localizado en otros sitios como manos, codos, rodillas y músculos. Afecta los músculos estriados en forma proximal, bilateral, progresiva y simétrica: toma la cintura escapular y pélvica y se acompaña de dolor e impotencia funcional. Otras afecciones acompañantes son: auriculares, del aparato digestivo, pleuropulmonar y cardiovascular. La etiología es desconocida, la teoría más aceptada indica que existiría una serie de alteraciones vasculares que serían el punto de partida del proceso histopatogénico, en especial de la dermatomiositis infantil, que representa un cuadro de "angiopatía sistémica". Los estudios diagnósticos son: 1) las enzimas séricas, en especial la CPK (específica de necrosis muscular) y otras como la aldolasa (más sensible), TGO y TGP; 2) la biopsia muscular muestra cambios incaracterísticos de inflamación aguda. El uso de prednisona aporta excelentes resultados terapéuticos. La dosis debe ser ajustada para obtener los mejores resultados con menores efectos adversos. En casos más grave se utilizarán inmunosupresores, como metotrexoto, azatioprina o ciclofosfamida. Ultimamente y en casos extremos se recurrirá a plasmaféresis, asociada a inmonosupresores. Es importante la fisioterapia precoz y el apoyo psicológico del paciente y la familia.