This test detects antibodies directed against proteinase 3, an enzyme found in certain white blood cells (neutrophils). These antibodies are closely linked to Granulomatosis with Polyangiitis (GPA), an autoimmune form of vasculitis that causes inflammation and damage in small blood vessels, particularly in the sinuses, lungs, and kidneys.
Diagnostic Value: Anti-PR3 is a key marker for GPA (formerly Wegener’s granulomatosis) and helps differentiate it from other types of vasculitis. A positive result supports diagnosis, especially when combined with characteristic clinical findings.
Disease Monitoring: Levels of Anti-PR3 antibodies may correlate with disease activity, making this test useful for tracking response to treatment and detecting relapses early.
Symptom Correlation: Patients with Anti-PR3 antibodies may present with chronic sinusitis, cough, shortness of breath, hematuria (blood in urine), or general inflammation symptoms such as fatigue and fever.
Because of its diagnostic precision and clinical relevance, the Anti-PR3 test is an essential tool for identifying and managing autoimmune vasculitis affecting vital organs.