LETTERS Prevalence

of anti-endothelial cell antibodies in idiopathic pulmonary arterial hypertension To the Editors: Pulmonary arterial hypertension (PAH) is a rare disease often resulting in right-sided heart failure and premature death [1]. PAH is idiopathic (IPAH), heritable, or related to conditions such as connective tissue diseases (CTD) [2]. IPAH prognosis remains poor despite improved patient survival with current treatment options. Therefore, elucidating the pathophysiology of IPAH is important for the discovery of novel therapeutic approaches. Inflammation and immune reactivity have been implicated in the pathophysiology of IPAH. In 2005, TAMBY et al. [3] described the presence of anti-endothelial cell antibodies (AECA) in IPAH, pointing at the involvement of humoral immunity. AECA are a heterogeneous family of auto-anti