American Board of Internal Medicine (ABIM) Certification Practice Exam

Which of the following diseases is associated with p-ANCA?

1. Granulomatosis with polyangiitis

2. Eosinophilic granulomatosis with polyangiitis

3. Hypertension

4. Systemic lupus erythematosus

The correct answer is: Eosinophilic granulomatosis with polyangiitis

P-ANCA (perinuclear anti-neutrophil cytoplasmic antibodies) is primarily associated with certain types of vasculitis and autoimmune disorders. Eosinophilic granulomatosis with polyangiitis, formerly known as Churg-Strauss syndrome, is particularly noted for its association with p-ANCA. This condition is characterized by asthma, eosinophilia, and systemic vasculitis that often affects small to medium-sized blood vessels. The presence of p-ANCA helps in the diagnosis of eosinophilic granulomatosis with polyangiitis, as these antibodies target myeloperoxidase, an enzyme found in neutrophils, which becomes prominent during the inflammatory processes associated with this disease. Other options, such as granulomatosis with polyangiitis, may be associated with c-ANCA (cytoplasmic anti-neutrophil cytoplasmic antibodies) rather than p-ANCA. Hypertension and systemic lupus erythematosus do not characteristically involve p-ANCA as part of their diagnostic criteria. Understanding the specific antibody associations can significantly aid in determining the underlying condition causing vasculitis and related symptoms.