PR3

The PR3, also known as the Proteinase 3 (PR3) antibody test, measures the presence of antibodies directed against proteinase 3, which is an enzyme found in neutrophils (a type of white blood cell). The presence of these antibodies are often associated with autoimmune conditions, particularly granulomatosis with polyangiitis (GPA), a form of vasculitis.  Elevated PR3 antibody levels can indicate active disease and may help in monitoring both the progression of the condition and the response to treatment.