Acute vasoreactivity testing is indicated in patients with idiopathic pulmonary arterial hypertension (IPAH) to identify subjects who will respond favorably to long-term treatment with calcium channel blockers (CCB) [1]. The result of the test determines the choice of treatment and predicts survival of the patient [2, 3]. It has been suggested that molecular etiology of IPAH is different in pat...

A rise in cytosolic Ca(2+) concentration ([Ca(2+)](cyt)) in pulmonary artery smooth muscle cells (PASMC) is a trigger for pulmonary vasoconstriction and a stimulus for PASMC proliferation and migration. Multiple mechanisms are involved in regulating [Ca(2+)](cyt) in human PASMC. The resting [Ca(2+)](cyt) and Ca(2+) entry are both increased in PASMC from patients with idiopathic pulmonary arteri...

To the Editor: We read with great interest the article in CHEST (June 2015) by Hautefort et al, 1 who demonstrated activity of the T helper 17 pathway in patients with idiopathic pulmonary arterial hypertension (IPAH). Th e authors further substantiated a potential role of an autoimmune pathogenesis in IPAH, a disease defi ned by the absence of known causes or associated conditions. “A fl avor ...

BACKGROUND Combination therapy has been proposed in treatment algorithms for idiopathic pulmonary arterial hypertension (IPAH), so the additional effects of bosentan in IPAH patients already treated with high-dose epoprostenol (EPO) was evaluated in the present study. METHODS AND RESULTS Bosentan (62.5 mg twice daily) was administered to 8 IPAH patients already being treated with high-dose EP...

RATIONALE Inflammatory cytokines may affect pulmonary vascular remodeling in idiopathic pulmonary arterial hypertension (IPAH). CC chemokine ligand 2 (CCL2) is synthesized by vascular cells and can stimulate monocyte/macrophage migration and smooth muscle cell (SMC) proliferation. OBJECTIVES To investigate the role of CCL2 in IPAH. METHODS CCL2 levels in plasma, monocytes, lungs, and medium...

OBJECTIVES The purpose of our study was to assess pulmonary endothelial function by vasodilator response to acetylcholine (Ach) administered in segmental pulmonary arteries in children with idiopathic pulmonary arterial hypertension (IPAH). We hypothesized that there was a relationship among pulmonary endothelial response to Ach, severity of the disease, and clinical outcome. BACKGROUND IPAH ...

The pore-forming alpha-subunit, Kv1.5, forms functional voltage-gated K(+) (Kv) channels in human pulmonary artery smooth muscle cells (PASMC) and plays an important role in regulating membrane potential, vascular tone, and PASMC proliferation and apoptosis. Inhibited Kv channel expression and function have been implicated in PASMC from patients with idiopathic pulmonary arterial hypertension (...

BACKGROUND Limited data are available describing paediatric pulmonary arterial hypertension. AIMS To characterize the epidemiology, management and impact on quality of life and outcome of paediatric pulmonary arterial hypertension, excluding persistent pulmonary hypertension of the newborn and pulmonary arterial hypertension caused by congenital heart disease. METHODS In this multicentre st...

RATIONALE Angiopoietins are involved in blood vessel maturation and remodeling. OBJECTIVES One consequence of endothelium-specific tyrosine kinase-2 (Tie2) receptor activation by angiopoietin-1 (Ang1) is the release of endothelium-derived growth factors that recruit vascular wall cells. We investigated this process in idiopathic pulmonary arterial hypertension (iPAH). METHODS Ang1, Ang2, an...