This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
p-ANCA is characteristic for: 
Select and explain. 
A. PAN, B. Microscopic polyangitis, C. Wegener's granulomatosis, D. Henoch-Schonlein purpura
B: Microscopic polyangitis
Answer: B: Microscopic polyangitis 
Explanation: Answer is B (Microscopic polyangitis) : PAN can broadly be classified into Classic PAN (now referred to an PAN) Classified as Medium Vessel Vasculitis Necrotizing inflammation of small & medium sized aeries. No involvement of capillaries & venules Pulmonary vasculature is not involved. ANCA mostly negative (Rarely p-ANCA may be seen) Microscopic PAN (now called microscopic polyangitis) Classified as small vessel vasculitis Necrotizing inflammation of small & medium sized aeries. Capillaries & venules are involved Pulmonary vasculature is involved. ANCA positive (p-ANCA)