Constitutional symptoms such as weight loss, fever, fatigue, and malaise are commonly present.[7] Elevation of serum PR3-ANCA titers occurs in most patients with clinical diagnoses of active GPA, but a significant minority are myeloperoxidase-ANCA positive or have a negative ANCA.[8] Granulomatous inflammation and multinucleated giant cells are key definitive pathological hallmarks in the diagnostic evaluation of GPA.[6,9] The diagnosis of GPA is based on a combination of clinical evaluations, imaging findings, laboratory tests, and histopathologic results. This evidence concerns the gene MPO and granulomatosis with polyangiitis.