Diagnosis and management of ADA2 deficient polyarteritis nodosa.

Deficiency of ADA2 (DADA2) is a recently described systemic inflammatory vasculopathy caused by mutations in the CERC1 gene that often, but not always, clinically resembles polyarteritis nodosa (PAN). The condition was originally characterized by livedoid rash, systemic inflammation, variable hypogammaglobulinemia, and early-onset stroke. The phenotypic spectrum has expanded to include patients with immunodeficiency syndromes and bone marrow dysfunction, which are not typical features of PAN. Exploration into the pathogenesis and treatment options of DADA2 has added to our understanding of this condition, but more studies are needed. The purpose of this article is to review the various clinical phenotypes of DADA2, and raise awareness among rheumatologists to consider DADA2 when evaluating patients presenting with PAN-like disease.