Pathogenic autoantibodies in systemic sclerosis.

Systemic sclerosis, scleroderma, is a disease characterized by widespread vascular injury and fibrosis of the skin and visceral organs. Circulating autoantibodies against several intracellular antigens are common in scleroderma patients. The specificities of such autoantibodies correlate with distinct clinical manifestations. However, till date there is no evidence that these autoantibodies, though helpful in diagnosis and prognosis, are linked to the pathogenesis of scleroderma nor that they may cause any feature of the disease. Recently, the discovery of novel agonistic autoantibodies targeting the PDGF receptor has provided important insight into the molecular pathogenesis of scleroderma and the intracellular mechanisms leading to fibrosis. Although their pathogenic role awaits validation in in vivo models, these antibodies represent the molecular link between the immune system and fibrosis.