Update on juvenile dermatomyositis: new advances in understanding its etiopathogenesis.

PURPOSE OF REVIEW: Juvenile dermatomyositis is the most common of the idiopathic inflammatory myopathies in children. It is considered an autoimmune disease of relatively unknown etiology, although environmental exposures and infectious agents are thought to play a role in disease pathogenesis. More recently, data has become available regarding the molecular genetics of children affected with juvenile dermatomyositis and the impact these genes have on disease expression and clinical course. Additionally, features of the immune response, including specific pathways of the humoral and cellular immune systems, have been further described. This article summarizes the most recent advances in understanding the etiopathogenesis of juvenile dermatomyositis.

RECENT FINDINGS: This article focuses on advances made in understanding the role that complement, soluble adhesion molecules, thrombospondin-1 levels, and genetics play in the evolution of juvenile dermatomyositis. It also describes microarray technology and gene expression profiling as means of identifying those genes overexpressed in affected children and thus likely involved in disease pathogenesis; microarray technology may also be used to distinguish dermatomyositis from the other inflammatory myopathies, as well as from other myopathies.

SUMMARY: In better understanding the pathogenetic mechanisms whereby disease evolves and the means by which genetic profiles influence susceptibility to and expression of disease, immunotherapies to better treat juvenile dermatomyositis may become available in the future.