[Microscopic polyarteritis].

Microscopic polyarteritis is a type of vasculitis that shows similar characteristics to other illnesses from the same group. This group presents a common clinical fact: a rapidly progressive glomerulonephritis. We specially point out among this group of illnesses the Wegener granulomatosis. The anti-neutrophil cytoplasmic antibodies is important for two different reasons. The fact that sometimes they have allowed to make differential diagnosis and that they represents so far the only serologic marking of such vasculitis. The ANCA antimieloperoxidasa (p-ANCA) can be found in a greater level in microscopic poliarteritis as well as the antiproteinasa-3 (c-ANCA) in the Wegener granulomatosis. The current revision tries to clarify the differential diagnosis of the microscopic poliarteritis, which nowadays is still quite vague. This lack can be compensated thanks to the fact that the therapeutic treatment of this group of illnesses is very similar.