Functional autoantibodies in systemic sclerosis.

Functional autoantibodies are an emerging field of research that focuses on the effects of these immunoglobulins when they bind to their target molecules. Accumulating information now exists about the molecular targets and precise binding mechanisms of functional autoantibodies as well as about their downstream effects. These data raise the need to distinguish functional autoantibodies from non-functional autoantibodies with regard to their ability to stimulate or to inhibit their target protein via binding. The presence of autoantibodies has been documented in autoimmune disorders decades ago, but meanwhile, more and more autoantibodies have been identified as functional, acting as pathogenic drivers involved in the induction of organ-specific damage in systemic sclerosis as well as in other autoimmune disorders. These findings offer new opportunities for the development of novel therapeutic strategies.