The antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) comprise granulomatosis with polyangiitis (GPA), commonly seen with antibodies to proteinase 3 (PR3-ANCA), and microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA), both principally associated with antibodies to myeloperoxidase (MPO-ANCA).  Our understanding of the complex pathogenesis of these vasculitides has evolved over the last decade. Kallenberg et al recently reviewed this topic in AJKD.  The following questions based on the article will test your knowledge on this topic:

1. All of the following are true except:

A. The ANCA-associated vasculitides (AAVs) comprise GPA, MPA, and EGPA

B. These diseases are characterized by pauci-immune necrotizing small vessel vasculitides and GN, combined with granulomatous inflammation in the airways.

C. MPA is associated primarily with PR3-ANCA, whereas GPA and EGPA are associated mainly with MPO-ANCA.

D. A significant proportion of patients with EGPA have no detectable ANCA levels.

E. C&D.

2. Which of the following is false?

A. Relapses in AAVs occur far more frequently in patients with PR3-ANCA than those with MPO-ANCA.

B. Both reconstitution of B cells after rituximab therapy and rising ANCA titers predict relapse in most cases of AAVs.

C. It has been recently proven that ANCAs play a pathogenic role.

D. PR3-ANCA is associated with granulomatous inflammation, incidences of more extrarenal disease, and faster decline in kidney function

3. Animal studies indicate that tissue injury in MPO-ANCA associated vasculitides involve which of the following:

A. Local release of MPO by activated neutrophils.

B. MPO-specific CD4+ T cells causing delayed-type hypersensitivity vascular injury.

C. A&B.

4. Which of the following is true regarding ANCA-negative pauci-immune GN?

A. ANCA-negative pauci-immune necrotizing GN occurs in 30% of cases.

B. Patients with ANCA-negative pauci-immune necrotizing GN tend to be younger.

C. Patients with ANCA-negative pauci-immune necrotizing GN have less systemic involvement.

D. Patients with ANCA-negative pauci-immune necrotizing GN have more chronic kidney disease.

E. All of the above.

5. All of the following are true regarding relapse of AAVs except:

A. The presence of PR3-ANCA and cardiovascular disease has been associated with a higher relapse rate.

B. Decreased kidney function has been associated with a lower relapse rate.

C. Staphylococcus aureus contains various superantigens that stimulate T-cell expression that strongly increases the risk of relapse.

D. Silica exposure has not been found to have an impact on AAVs.

Post prepared by Dr. Azzour Hazzan and eAJKD Editor Dr. Kenar D. Jhaveri, both from Hofstra NSLIJ School of Medicine

To see answers, please click here.

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