Figure 1.

Overview of major inflammatory pathways involved in the pathogenesis of pulmonary arterial hypertension. Initial vascular injuries lead to increase in cytokines in vascular cells. After secretion into the bloodstream, cytokines promote accumulation of circulating neutrophils and monocytes, and T and B lymphocytes, resulting in increased vascular proliferation and damage. TNF-α=tumour necrosis factor α; IL=interleukin, MCP=monocyte chemoattractant protein, SMC=smooth muscle cell, CCL=C-C motif chemokine ligand