A 36-year-old woman presents with muscle pain, fever, chronic sinusitis. Physical examination shows mucosal ulcerations of the nasopharynx. A biopsy from her nasopharynx reveals necrotizing vasculitis with chronic inflammatory cells and giant cells surrounding necrotic areas. The presence of which of the following autoantibodies would be most consistent with a diagnosis of Wegener&;s granulomatosis

Wegener granulomatosis (WG) is a disease characterized by focal necrotizing vasculitis and acute necrotizing granulomas of the upper and lower respiratory tract. Renal involvement is common. The clinical signs associated with WG include perforation of the nasal septum, chronic sinusitis, hemoptysis, and hematuria. Patients with WG who have renal involvement may have a positive test for the presence of antineutrophil cytoplasmic antibodies, which are antibodies directed against the primary granules within neutrophils. There are two basic types of ANCA: p-ANCA and c-ANCA. p-ANCA refers to perinuclear staining, and c-ANCA indicates cytoplasmic staining after ethanol fixation and immunofluorescence. Patients with WG most commonly have c-ANCA. Ref:- Harsha Mohan textbook of Pathology