Are there specific serologic markers for any of these vasculitic disorders?

Yes. Antimyeloperoxidase antibodies directed against cytoplasmic components of neutrophils have been used to help identify patients with segmental necrotizing glomerulonephritis and some types of systemic vasculitis. Antibodies directed against serine proteinase 3 that is found in the cytoplasm of neutrophils (c-ANCA) have been detected in 66% to 90% of patients with active Wegener’s granulomatosis. Patients with pulmonary-renal syndrome who have antibodies directed against cytoplasmic myeloperoxidase, in neutrophils that produce a peripheral antineutrophil cytoplasmic pattern (p-ANCA), are most likely to have microscopic polyangiitis.

Harper L, Savage CO: Pathogenesis of ANCA-associated systemic vasculitis, J Pathol 190:349–359, 2000.