強皮症と自己免疫

抄録

Scleroderma is an autoimmune disorder characterized by fibrosis in the skin and is divided into two types: systemic sclerosis and localized scleroderma. The etiology and pathogenesis of scleroderma are still unclear. Autoantibodies have been useful diagnostic tools and their clinical significance is reviewed in this article. Furthermore, recent studies have revived the idea that autoantibodies and B lymphocytes play principal roles in systemic autoimmune diseases. In the tight skin (Tsk/+) mouse, a genetic model of systemic sclerosis, B cells exhibit a hyper-responsive phenotype due to the disruption of the CD22/SHP-1 negative regulatory pathway. This inhibitory pathway is regulated by CD19, and the loss of CD19 expression significantly reduces skin fibrosis and autoantibody production in Tsk/+ mice. Two features of scleroderma, fibrosis and autoimmunity, thus affect each other, which may provide a clue to comprehending the pathogenesis of the disease.