Studies of the Natural History, Pathogenesis, and Outcome of Idiopathic Systemic Vasculitis

The purpose of this protocol is to study the natural history of idiopathic systemic vasculitis in children and adults. The idiopathic vasculitides are a group of rare, systemic diseases involving inflammation of arteries and other tissue with resulting organ- and life-threatening disease courses. The different forms of idiopathic vasculitis are typically classified based upon the predominant size of the arteries affected in each condition, including small vessel vasculitis [granulomatosis with polyangiitis (GPA, Wegener s), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA, Churg-Strauss)]; medium vessel vasculitis [polyarteritis nodosa (PAN)]; and large vessel vasculitis [giant cell arteritis (GCA), Takayasu s arteritis (TAK), idiopathic aortitis (IA)]. Although patients with each type of vasculitis manifest disease-specific aspects of illness, there are substantial disease and treatment burdens common to patients with vasculitis. For each type of idiopathic vasculitis, the disease course is often chronic, relapse is common and unpredictable, organ and tissue damage can accrue over time, new symptoms can occur late into the disease course, and treatment is often associated with toxicity and serious side effects.

The goals of this natural history protocol are to establish a cohort of pediatric and adult patients with vasculitis to prospectively evaluate the signs and symptoms, imaging findings, and blood and tissue biomarkers associated with pathogenesis and disease outcomes. In the small vessel vasculitides, where considerable progress has been made towards identifying pathologic mechanisms of disease, we will focus on elucidating the pathogenic role of neutrophils, selected biomarkers such as SERPINA1, and novel candidate biomarkers in circulating blood and at local tissue sites including the nasal mucosa. In the medium and large vessel vasculitides, we will identify novel candidate biomarkers for disease pathogenesis and outcomes and develop disease activity indices that incorporate existing and novel clinical, laboratory, genomic, and imaging biomarkers. For all types of vasculitis, a goal of the protocol is to identify patients for possible entry into future treatment studies.

Patients enrolled in this protocol will undergo a history, physical examination, and laboratory evaluation. Since vasculitis is multi-system disease with variable patterns of organ involvement, patients may undergo further comprehensive evaluation of a particular affected organ system when clinically indicated. Peripheral blood samples will be collected from affected patients, unrelated healthy volunteers matched for age, sex, and ethnicity whenever possible, and in some cases unaffected family members to help identify and study the genes involved in vasculitis and their functions. We may ask some patients to undergo nasal biopsy and additional imaging studies for research purposes. For a small number of patients and family members, we may ask permission to perform whole genome or exome sequencing. Successful completion of these studies will improve our understanding of disease pathogenesis.