Monocytes/Macrophages in Giant Cell Arteritis-Polymyalgia Rheumatica Spectrum Disease.

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are closely related inflammatory diseases that predominantly affect individuals over 50 years of age. The pathogenesis of two diseases is unclear. Accumulating evidence indicates that aberrant innate and adaptive immune responses underlie the pathogenesis of GCA and PMR. Monocytes/macrophages play an important role in the inflammatory processes through producing proinflammatory cytokines and chemokines, modulating molecular expression, colony-stimulating factors, proteolytic enzymes, and growth factors, and activating the JAK/STAT pathway. Clarifying the functions of monocytes/macrophages may help find targets for these diseases. Current research is investigating potential treatments such as proinflammatory cytokine blockers, anti-CXCR3 agents, competitive antagonists of GM-CSF activity, and JAK inhibitors in patients with GCA or PMR. In this study, we examine the role of monocytes and macrophages in the pathogenesis of GCA and PMR, identify potential drug targets, novel therapeutic strategies and future research directions.