All of the following are true regarding Wegener's granulomatosis except: September 2008

Ans. A: Affects large size blood vesselsWegener's granulomatosis is a form of vasculitis that affects the lungs, kidneys and other organs.Due to its end-organ damage, it is life-threatening and requires long-term immunosuppression.Wegener's granulomatosis is pa of a larger group of vasculitic syndromes, all of which feature an autoimmune attack by an abnormal type of circulating antibody termed ANCAs (antineutrophil cytoplasmic antibodies) against small and medium-size blood vessels.Apa from Wegener's, this category includes Churg-Strauss syndrome and microscopic polyangiitis.Cytoplasmic staining ANCAs that react with the enzyme proteinase 3 (cANCA) in neutrophils are associated with Wegener's (upto 95% of cases).If the patient has renal failure or cutaneous vasculitis, these are the most logical organs to obtain a biopsy from.On histopathological examination, a biopsy will show leukocytoclastic vasculitis with necrotic changes and granulomatous inflammation on microscopy. These granulomas are the main reason for the appellation of "Wegener's granulomatosis", although it is not an essential feature.