Granulomatosis with polyangiitis - multisystem involvement


According to the 1990 American College of Rheumatology criteria, two of the following are required for a diagnosis of granulomatosis with polyangiitis to be made:

  • positive biopsy for granulomatous vasculitis
  • urinary sediment with red blood cells 
  • abnormal chest radiograph 
  • oral or nasal inflammation 

The classic triad of organ involvement consists of:

  • lungs: involved in ~95% of cases
  • upper respiratory tract / sinuses: ~75-90%
  • kidneys: ~80%