Microscopic PolyangiitisWegener GranulomatosisVasculitisAntibodies, Antineutrophil CytoplasmicPolyarteritis NodosaChurg-Strauss SyndromeVasculitis, Leukocytoclastic, CutaneousSystemic VasculitisMyeloblastinAnti-Neutrophil Cytoplasmic Antibody-Associated VasculitisPeroxidaseGlomerulonephritisPlasma ExchangeSkin Diseases, VascularImmunosuppressive AgentsPrednisoloneIleal DiseasesCyclophosphamideMethylprednisoloneAdrenal Cortex HormonesUlcerHemorrhageGlucocorticoidsLung DiseasesSerine EndopeptidasesKidney DiseasesBiopsyFluorescent Antibody Technique, IndirectRecurrence