This case highlights a rare instance of GPA-related aortitis progressing to Stanford type A aortic dissection within 48 hours, confirmed by PR3-ANCA (4.3 AI), c-ANCA (1:20), ESR (77 mm/hr), CRP (5.53 mg/dL), and CTA findings. Here, CRP is linked to granulomatosis with polyangiitis.