Antineutrophil cytoplasm autoantibodies: usefulness in rheumatology

The primary vasculitidies are complex diseases with varied clinical manifestations, which may be common to those present in multiple diseases. The antineutrophil cytoplasm autoantibodies (ANCA) led to a revolution in the diagnosis and research of these diseases, being the first and so far, the only biomarkers for three of these diseases, which affect small caliber vessels. From their description, much progress has been made, but there are still gray or misunderstood areas regarding their best use in the clinic. This can lead to errors as making a positive test synonym for vasculitis, or to overestimation of its importance. This review will address aspects such as nomenclature, employment in the diagnosis and monitoring of vasculitis, their presence in other diseases, their methods of detection, and finally, some comments on other potential biomarkers in vasculitis.