RESUMO
Dermatomyositis (DM) is a chronic inflammatory disorder of the skin and muscles. Although thought to be autoimmune in origin, many questions remain as to the etiopathogenesis of this disease. DM has classically been considered a humorally mediated disease. Current evidence, however, seems to increasingly support alternative (though not mutually exclusive) mechanisms of pathogenesis, including cell-mediated and innate immune system dysfunction. Pathologic findings of DM in muscle include infarcts, perifascicular atrophy, endothelial cell swelling and necrosis, vessel wall membrane attack complex deposition, and myocyte-specific MHC I upregulation. As for the skin, histopathologic findings include hyperkeratosis, epidermal basal cell vacuolar degeneration and apoptosis, increased dermal mucin deposition, and a cell-poor interface dermatitis. Autoantibodies, particularly those that bind nuclear or cytoplasmic ribonucleoprotein antigens, are also commonly found in DM, although their importance in pathogenesis remains unclear. Defective cellular clearance, genetic predilection and environmental exposures, such as viral infection, may also play an important role in the pathogenesis of DM. The seminal work regarding the pathogenesis of DM is reviewed and an update on the recent basic and molecular advances in the field is provided.
Assuntos
Doenças Autoimunes , Dermatomiosite , Animais , Anticorpos Antinucleares/imunologia , Formação de Anticorpos/genética , Autoantígenos/imunologia , Doenças Autoimunes/etiologia , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Membrana Basal/imunologia , Membrana Basal/patologia , Doença Crônica , Dermatomiosite/etiologia , Dermatomiosite/genética , Dermatomiosite/imunologia , Dermatomiosite/patologia , Endotélio Vascular/imunologia , Endotélio Vascular/patologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Imunidade Celular/genética , Imunidade Inata , Células Musculares/imunologia , Células Musculares/patologia , Músculos/imunologia , Músculos/patologia , Pele/imunologia , Pele/patologia , Regulação para Cima/genética , Regulação para Cima/imunologia , Vacúolos/genética , Vacúolos/imunologia , Vacúolos/patologiaRESUMO
OBJECTIVE: To evaluate the validity of the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) for use by rheumatologists via reliability testing, and to extend the validation for dermatologists. METHODS: Fourteen subjects with cutaneous lupus erythematosus (CLE; n = 10), a mimicker skin disease only (a cutaneous lesion that may appear clinically similar to CLE; n = 1), or both (n = 3) were rated with the CLASI by academic-based dermatologists (n = 5) and rheumatologists (n = 5). RESULTS: The dermatology intraclass correlation coefficient (ICC) was 0.92 for activity and 0.82 for damage; for rheumatology the ICC was 0.83 for activity and 0.86 for damage. For intrarater reliability, the dermatology Spearman's rho was 0.94 for activity and 0.97 for damage; for rheumatology the Spearman's rho was 0.91 for activity and 0.99 for damage. CONCLUSION: Our data confirm the reliability of the CLASI when used by dermatologists and support the CLASI as a reliable instrument for use by rheumatologists.
