The Myeloperoxidase IgG ELISA test system is intended for the qualitative and semi-quantitative detection of IgG-class antibody to myeloperoxidase 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 antineutrophil cytoplasmic antibodies (ANCA). MPO-ANCA may be associated with autoimmune disorders such as Wegener's granulamotosis, ICGN, MPA and PRS.