PT - JOURNAL ARTICLE AU - Perros, Frédéric AU - Humbert, Marc AU - Dorfmüller, Peter TI - Smouldering fire or conflagration? An illustrated update on the concept of inflammation in pulmonary arterial hypertension AID - 10.1183/16000617.0161-2021 DP - 2021 Dec 31 TA - European Respiratory Review PG - 210161 VI - 30 IP - 162 4099 - http://err.ersjournals.com/content/30/162/210161.short 4100 - http://err.ersjournals.com/content/30/162/210161.full SO - EUROPEAN RESPIRATORY REVIEW2021 Dec 31; 30 AB - Pulmonary arterial hypertension (PAH) is a rare condition that is characterised by a progressive increase of pulmonary vascular resistances that leads to right ventricular failure and death, if untreated. The underlying narrowing of the pulmonary vasculature relies on several independent and interdependent biological pathways, such as genetic predisposition and epigenetic changes, imbalance of vasodilating and vasoconstrictive mediators, as well as dysimmunity and inflammation that will trigger endothelial dysfunction, smooth muscle cell proliferation, fibroblast activation and collagen deposition. Progressive constriction of the pulmonary vasculature, in turn, initiates and sustains hypertrophic and maladaptive myocardial remodelling of the right ventricle. In this review, we focus on the role of inflammation and dysimmunity in PAH which is generally accepted today, although existing PAH-specific medical therapies still lack targeted immune-modulating approaches.Several pro-inflammatory triggers and pathways ignite and fuel persistent pulmonary vascular inflammation and obstructive vascular remodelling in PAH. Individual inflammatory susceptibility might reveal responder populations for immunomodulatory therapies. https://bit.ly/3GC1XMC