Autoantibodies in connective tissue disease.

Autoimmune connective tissue diseases are heterogeneous rheumatic diseases with the potential to affect multiple body systems. Autoantibodies are a characteristic feature of these diseases and are typically highly disease specific. In addition to aiding diagnosis, many autoantibodies have established associations with clinically important disease complications including internal organ involvement. In this chapter, we review the autoantibodies relevant to autoimmune connective tissue diseases, excluding systemic lupus erythematosus, with particular reference to the associated clinical features and how identification of such an autoantibody may inform prognosis and clinical management. We also discuss the practicalities of testing for autoantibodies along with potential difficulties and pitfalls.