Mast cells and primary systemic vasculitides.

Vasculitides are characterized by inflammation and necrosis of blood vessels leading to vessel occlusion and ischemic damages of tissues. Among the inflammatory cells involved in vasculitides, neutrophils, T cells, and macrophages have been identified as the predominant cell type. This review article is focused on the role of mast cells in these chronic inflammatory processes. Mast cells are characterized by their complex plasticity. Increasing evidences document that mast cells exert both pro- and anti-inflammatory functions depending on the cell types and the microenvironment they reside in. In this context, mast cell mediators able to modulate progression of vasculitides at different levels and the anatomic localization of mast cells in different vasculitides will be described. Finally, therapeutic approach including inhibition of recruitment of mast cells to the inflammatory infiltrate and blockade of their proinflammatory effects and proangiogenic functions as potential new targets for the treatment of these diseases will be discussed.