The Proteinase-3 IgG ELISA test system is intended for the qualitative and semi-quantitative detection of anti- Proteinase-3 IgG antibody in human serum. The test system is intended to be used as an aid in the diagnosis of various autoimmune vasculitic disorders characterized by elevated levels of anti-neutrophil cytoplasmic antibodies (ANCA). PR-3-ANCA may be associated with autoimmune disorders such as Wegener's granulamotosis, ICGN, MPA, and PRS.