Used in clinical and research laboratories to detect and quantify anti-neutrophil cytoplasmic antibodies (ANCA) specific to proteinase 3 (PR3) in human serum or plasma. This kit supports the diagnosis and monitoring of autoimmune vasculitides, particularly granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis. The assay aids in differentiating PR3-ANCA positive vasculitis from other autoimmune diseases and helps assess disease activity and response to treatment. It is intended for research use only and not for diagnostic procedures in all regions—users should verify regulatory status locally. The ELISA format allows for high-throughput screening with reliable sensitivity and specificity when used with proper controls and protocols.