ANCA associated vasculitis (AAV): a review for internists

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ABSTRACT

Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) compromise a rare group of necrotizing small to medium vessel vasculitides that constitute three distinct disorders: granulomatosis with polyangiitis (GPA) (formerly known as Wegener’s granulomatosis), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA) (formerly known as Churg-Strauss syndrome). AAV is characterized by the usual presence of circulating autoantibodies to the neutrophil proteins leukocyte proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA). These antibodies can activate neutrophils and the complement system resulting in vessel wall inflammation and damage. The clinical presentation of AAV varies from non-severe (non-life threatening) to severe often with potentially life-threatening multi-organ involvement. Early recognition and diagnosis are crucial. In the past two decades, advances in understanding the pathophysiology of AAV have led to development of new treatments and resulted in significant improvement in general outcomes and survival rates. This narrative review will focus on GPA and MPA. We will highlight clinical manifestations, diagnosis, disease monitoring, and treatment strategies in patients with AAV.

KEYWORDS:

• ANCA associated vasculitis
• granulomatosis with polyangiitis (GPA)
• microscopic polyangiitis (MPA)
• advances in treatment

Key notes

• The clinical spectrum of AAV is broad and the initial presentation can mimic that of infections, post viral syndromes, or malignancy.

• Lung and renal involvement in AAV can be asymptomatic. Therefore, prompt screening with urinalysis and chest imaging is necessary in all suspected patients. We believe chest CT imaging is far more sensitive than standard radiographs.

• Results of ANCA tests at the time of initial evaluation and throughout disease course in confirmed cases must be interpreted carefully. They are not totally specific and may not parallel disease activity.

• Recent studies have focused on reducing cumulative GC dose used in AAV treatment by utilizing other therapies

• AAV is a relapsing disease, and generally requires long-term maintenance therapy and vigilant monitoring.

• Vaccinations and prophylactic therapy to prevent pneumocystis and osteoporosis and appropriate screening for malignancy is a necessary part of routine patient care.

Disclosure statement

Dr. Mandell served as a consultant to ChemoCentryx Inc prior to FDA approval of avacopan. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Declaration of Funding

No funding was received for the production of this manuscript.