Skeletal muscle major histocompatibility complex class I and II expression differences in adult and juvenile dermatomyositis

• Autor(a) principal: Shinjo, Samuel Katsuyuki
• Data de Publicação: 2012
• Outros Autores: Sallum, Adriana Maluf Elias, Silva, Clovis Artur, Marie, Suely Kazue Nagahashi
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Clinics
• Texto Completo: https://www.revistas.usp.br/clinics/article/view/45841
• topic: Adult Dermatomyositis; Idiopathic Inflammatory Myopathies; Juvenile Dermatomyositis; Major Histocompatibility Complex; Muscle Biopsy

OBJECTIVE: To analyze major histocompatibility complex expression in the muscle fibers of juvenile and adult dermatomyositis. METHOD: In total, 28 untreated adult dermatomyositis patients, 28 juvenile dermatomyositis patients (Bohan and Peter's criteria) and a control group consisting of four dystrophic and five Pompe's disease patients were analyzed. Routine histological and immunohistochemical (major histocompatibility complex I and II, StreptoABComplex/HRP, Dakopatts) analyses were performed on serial frozen muscle sections. Inflammatory cells, fiber damage, perifascicular atrophy and increased connective tissue were analyzed relative to the expression of major histocompatibility complexes I and II, which were assessed as negatively or positively stained fibers in 10 fields (200X). RESULTS: The mean ages at disease onset were 42.0±15.9 and 7.3±3.4 years in adult and juvenile dermatomyositis, respectively, and the symptom durations before muscle biopsy were similar in both groups. No significant differences were observed regarding gender, ethnicity and frequency of organ involvement, except for higher creatine kinase and lactate dehydrogenase levels in adult dermatomyositis (p