Innate Immunity in Vasculitis

Systemic vasculitis is a heterogeneous group of rare diseases characterized by inflammation in vessel walls. Vasculitides are mainly classified based on the size of the vessels predominantly affected as large-, medium- and small-vessel vasculitis. When no specific etiology is associated, vasculitis is named as primary systemic vasculitis, whereas, systemic autoimmune or inflammatory conditions, acute or chronic infections, medications, and even malignancies act as etiologic agents for the vasculitic process. Pathogenic mechanisms of systemic vasculitis are diverse and include granulomatous inflammation, neutrophilic infiltration with leukocytoclasia and neutrophils extracellular traps (NET) production, immune complexes deposition, autoantibody production such as antineutrophil cytoplasmic antibodies (ANCA) to name but a few. Innate immune cells such as neutrophils, eosinophils, monocytes, macrophages and NK cells play an important role in the pathogenesis of this group of diseases. Recently described genetic defects such as deficiency of adenosine deaminase 2 (DADA2) and Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome are also known to present with vasculitis, the pathogenesis of which is mainly mediated by aberrant activation of the innate immune system.

The complex nature and the rarity of systemic vasculitis is a challenge for conducting research in this area. Several gaps need to be unraveled in the knowledge of the pathophysiology of this intriguing group of systemic inflammatory and autoimmune diseases. Therefore, the aim of this research topic is to present novel evidence of innate immunity mechanisms in driving systemic inflammation, as well as vessel wall inflammation and damage to different organs and systems in patients with systemic vasculitis. We would like to approach issues regarding pathophysiologic mechanisms of innate immunity in systemic vasculitides including the description of molecular and cellular pathways, the participation of specific innate immune cell subsets, biomarkers, alarmins, aging of the innate immune system, monogenic vasculitis, animal models and potential targeted therapy for different forms of systemic vasculitis.

In this Research topic, we seek manuscripts evaluating different aspects of the role of the innate immune system in the pathogenesis of different forms of systemic vasculitis such as large-vessel vasculitis (i.e., Takayasu arteritis and giant cell arteritis), medium-vessel vasculitis (i.e., polyarteritis nodosa and Kawasaki’s disease), small-vessel vasculitis (ANCA-associated vasculitis, IgA vasculitis, cryoglobulinemic vasculitis, anti-glomerular basement membrane disease, and hypocomplementemic urticarial vasculitis), Behçet’s disease and monogenic vasculitides (such as DADA2 and VEXAS). Manuscripts in the form of original research articles, review articles, systematic reviews with or without metanalysis, and manuscripts describing new in vitro methods are all welcome.