American Board of Internal Medicine (ABIM) Certification Practice Exam

Which of the following conditions is associated with the presence of PR3-ANCA?

1. Granulomatosis with polyangiitis (Wegener)

2. Microscopic polyangiitis

3. Polyarteritis Nodosa

4. Churg-Strauss syndrome

The correct answer is: Granulomatosis with polyangiitis (Wegener)

The condition associated with the presence of PR3-ANCA is Granulomatosis with polyangiitis, formerly known as Wegener's granulomatosis. This autoimmune disorder is characterized by the involvement of small to medium-sized vessels, leading to vasculitis, and it typically presents with symptoms affecting the upper and lower respiratory tracts, as well as renal involvement. The presence of PR3-ANCA (anti-proteinase 3 antibodies) is particularly significant in this condition because it helps in the diagnosis and is associated with the disease's severity and relapses. PR3-ANCA testing is routinely used in clinical practice, and a positive result can support the diagnosis of Granulomatosis with polyangiitis in a patient exhibiting compatible clinical features. Other conditions listed, such as Microscopic polyangiitis, are more commonly associated with another type of ANCA, specifically MPO-ANCA (myeloperoxidase anti-neutrophil cytoplasmic antibodies). Polyarteritis Nodosa does not typically demonstrate ANCA positivity, and Churg-Strauss syndrome, also known as eosinophilic granulomatosis with polyangiitis, is more closely linked to the presence of MPO-ANCA