Chapter 13 - Targeting macrophages in systemic diseases

Abstract

Macrophages and monocytes are innate immune cells that play a crucial role in the pathogenesis of systemic autoimmune diseases. The current literature shows that specific monocyte subsets and macrophage subpopulations predominate in the peripheral blood and in tissues, respectively, according to the specific pathophysiology features of each disease. Classical monocytes are the predominant subtype in patients with giant cell arteritis, while intermediate monocytes are important players in rheumatoid arthritis, antineutrophil cytoplasmic antibody-associated vasculitis and Behcet disease. The non-classical monocytes prevail in systemic lupus erythematosus and in Sjögren syndrome. Regarding macrophages subpopulations, the M1 subtype is predominant in affected tissues of patients with rheumatoid arthritis, systemic lupus erythematosus and Kawasaki disease, whereas M2-macrophages are predominant in systemic sclerosis, Takayasu arteritis, antineutrophil cytoplasmic antibody-associated vasculitis and IgA vasculitis. This chapter highlights the role of monocytes and macrophages in the pathogenesis of different systemic autoimmune diseases, indicating the corresponding potential therapeutic opportunities.