BTG3 and aortitis: Autoimmune vasculitis giant cell arteritis (GCA) and Takayasu arteritis were unlikely as there was no obvious clinical history of those diseases (e.g. cranial symptoms or limbs calculation) and ANA, ANCA, and RF tests were negative.8 It was determined that IgG4-related aortitis would be excluded by having a normal serum IgG4.