GPA stands for Granulomatosis with PolyAngiitis. It is an ANCA Associated form of vasculitis (AAV) which is a subgroup of small vessel vasculitis . Until 2012 the disease was referred to as Wegener’s disease, Wegener’s Granulomatosis or Morbus Wegener. Dr. Wegener was the pathologist who first recognized the characteristics of this syndrome as a separate disease and published an important paper about it. GPA is most common form of AAV.