Pathophysiology: Wegener granulomatosis (WG), the most common of the pulmonary granulomatous vasculitides, typically involves the upper respiratory tract, lower respiratory tract (bronchi and lung), and kidney, with varying degrees of disseminated vasculitis. The term Granulomatosis with Polyangiitis (Wegener) was recently proposed to replace the older term, WG. The term granulomatosis with polyangiitis can be abbreviated to GPA, with the idea that the eponym Wegener would be omitted over time.
Diagnosis: Whenever possible, it is important to confirm the diagnosis of Wegener’s by biopsying an involved organ and finding the pathologic features of this disease under the microscope. Because many diseases may mimic Wegener’s (and vice versa), before starting a treatment regimen it is essential to be as certain of the diagnosis as possible.
Prior to the introduction of effective therapy, mean survival among patients with untreated active WG was less than 6 months more than 80% of patients died within 3 years of onset of symptoms, usually of progressive renal failure. Corticosteroids ameliorated many of the inflammatory manifestations of WG but were associated with only modest gains in survival (mean survival of only 12.5 months).
Statistics: The annual incidence of WG has been rising over the decades from <1 per million in the 1970s to current estimates of 4 to 12 cases per million Published annual incidence rates (per million) were 4.1 in Spain.