Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Granulomatosis with Polyangiitis ?
    ### Response:
    Granulomatosis with polyangiitis (GPA), previously known as Wegener's granulomatosis, is a rare disease. It is a type of vasculitis, or inflammation of the blood vessels. The inflammation limits the flow of blood to important organs, causing damage. It can affect any organ, but it mainly affects the sinuses, nose, trachea (windpipe), lungs, and kidneys.
    