Pulmonary microcirculation in interstitial lung disease.

Vascular abnormalities are a common feature of interstitial lung diseases (ILD). The development of pulmonary hypertension has been recognized as a condition that determines the overall prognosis, particularly for patients with idiopathic pulmonary fibrosis and scleroderma-associated lung disease. The treatment of chronic ILD is challenging due to the lack of causal therapies, specifically of the fibroproliferative component of the disorders, but also due to the vascular abnormalities. Recent studies suggest that the pathobiology underlying the remodeling and fibrosis of the parenchyma in ILD and the mechanisms leading to structural and functional alteration of the pulmonary vasculature are closely intertwined. This review summarizes the current understanding of the pathobiology of the microcirculation in ILD, with a specific focus on idiopathic pulmonary fibrosis and scleroderma-associated lung disease. An improved understanding of the complex biological mechanisms that link alveolar interstitial and vascular remodeling in chronic ILD will be required to identify novel drug targets.