The clinical aspects of autoantibodies

Disease classification in systemic sclerosis (SSc) is based primarily on the extent of skin involvement due to the recognition of its capacity to predict organ-specific manifestations. However, as shall be discussed in this chapter, antibody specificity, despite certain limitations, may prove of greater importance in predicting disease course and prognosis [1]. Circulating autoantibodies are attractive as biomarkers in SSc owing to their high specificity, the mutual exclusivity of the major SScautoantibody subtypes, their persistence for the duration of illness and most importantly, the characteristic constellation of clinical features associated with individual autoantibody groups [2, 3]. It is important to note, however, that the major clinical associations with SSc specific autoantibody reactivities, whilst of major prognostic value, are not absolute and organspecific manifestations can occur in the presence of any autoantibody reactivity [4].