Classification of the vasculitides: are they clinically useful?

Several classification systems for the vasculitides have been developed over the second half of the past century. These classifications systems have been modified according to the advances made in the differentiation of these syndromes, particularly their histopathologic features (the vessel size involved) and their clinical features. Although these classifications have been widely used in the clinical setting for the diagnosis of these disorders, they were developed for research purposes. Given the common clinical and, sometimes, histopathologic features of the different vasculitides, a classification system that facilitates a diagnosis and the formulation of a therapeutic plan is still needed. The development and utilization of novel serum markers and new imaging modalities coupled with advances in the understanding of these disorders, may allow the development of a classification system for the vasculitides that will be of greater value in the clinical setting.