A type of vasculitis that involves medium sized arteries. The name has been changed to granulomatosis with polyangiitis. Causes inflammation and narrowing of the blood vessels. It most often affects and damages the kidneys, lungs, and upper respiratory tract. The cause of the disease is not known. Left untreated the disorder is life threatening due to severe lung injury and /or kidney failure. This disease is more often seen in adults greater than 35 years old.