Correspondence: Joan A. Barberà Servei de Pneumologia, Hospital Clínic Villarroel, 170 08036 Barcelona, Spain E-mail: jbarbera@clinic.ub.es Date of reception: 17-07-2015 Date of acceptance: 04-08-2015 DOI: 10.23866/BRNRev:2015-M0007 Insights Into the Pathobiology of Pulmonary Hypertension Victor I. Peinado, Isabel Blanco, Olga Tura-Ceide and Joan Albert Barberà Department of Pulmonary Medicine, Hospital Clínic, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain; Biomedical Research Networking Center on Respiratory Diseases (CIBERES), Madrid, Spain REVIEW ARTICLE BRN Reviews PERMANYER www.permanyer.com www.brn.cat BRN Rev. 2015;1:63-77 INTRODUCTION Pulmonary hypertension (PH) is defined by an abnormal increase of pulmonary arterial pressure that may progress in right ventricu- lar impairment, right ventricular failure, and death. Pulmonary hypertension is a progres- sive disease of multifactorial aetiology, cur- rently classified into five groups based on histopathological appearance and treatment modalities: (i) pulmonary arterial hyperten- sion (PAH), (ii) PH due to left heart disease, ABSTRACT Pulmonary hypertension is a complex disorder defined by an abnormal increase of pulmonary arterial pressure that may result in right ventricular failure and death. Pulmonary hypertension has a multifactorial aetiology and is currently classified into five groups based on histo- pathological appearance and treatment modalities. Our understanding of the pathobiology of pulmonary hypertension has evolved enormously in recent years. A condition that in the past was considered mainly determined by increased vascular tone is now seen as a vasculopathy in which structural changes are driven by excessive cell growth. In the present review we analyse mechanisms that may contribute to the pathobiology of pulmonary hypertension, including imbalance between vasoactive mediators, altered cell proliferation and apoptosis, dysfunctional endothelial repair and angiogenesis, and contributing factors such as inflammation. (BRN Rev. 2015;1:63-77) Corresponding author: Joan A. Barberà, jbarbera@clinic.ub.es Key words: Apoptosis. Cell proliferation. Growth factors. Pulmonary artery wall. Vasoactive mediators. No part of this publication may be reproduced or photocopying without the prior written permission of the publisher. © Permanyer Publications 2017