Monocyte chemotactic protein (MCP)-1 (CCL2) and its receptor (CCR2) are elevated in chronic heart failure facilitating lung monocyte infiltration and differentiation which may contribute to lung fibrosis

•M1/M2 macrophages may regulate lung remodelling in chronic heart failure (CHF).•Raised MCP-1/CCL2 in CHF favours Mon 1 recruitment and activation of M2 in the lung.•Increases in plasma and lung MCP-1 in CHF is suggestive of a chemotactic gradient.•High blood and low lung CCR2 expression suggest monocyte maturation in the CHF lung.•The MCP-1/CCR2 axis provides a new mechanistic insight into CHF lung pathogenesis.