At the 2015 Vasculitis Symposium, it was stated by some of the most knowledgeable rheumatologists studying vasculitis that they still don't know what causes vasculitis, but they are working on it. There's also no cure for many forms. Some doctors believe that it's 50% environment and 50% genetic. In my mind, that means they don't know. They have said that vasculitis is not hereditary, but many family members do have other autoimmune problems, just not vasculitis.