Possible role of imatinib in clinical pulmonary veno-occlusive disease

The platelet-derived growth factor receptor inhibitor imatinib has demonstrated clinical and haemodynamical improvement in both animal models of pulmonary hypertension (PH) and patients with PH. It has been suggested that anti-proliferative effects on pulmonary vascular smooth muscle cells are responsible for these beneficial effects. The current study describes a patient with pulmonary arterial hypertension associated with a suspected pulmonary veno-occlusive disease. Treatment with imatinib resulted in rapid clinical improvement and decrease of ground-glass opacities and lobular septal thickening on high-resolution computed tomography. Based on these findings and on in vitro effects of imatinib on permeability of the endothelium, the authors hypothesise that the rapid clinical outcome is partly due to effects of imatinib on vascular integrity.