TY - JOUR T1 - Pulmonary arterial hypertension: an autoimmune disease? JF - European Respiratory Journal JO - Eur Respir J SP - 986 LP - 988 DO - 10.1183/09031936.05.00112105 VL - 26 IS - 6 AU - L. Mouthon AU - L. Guillevin AU - M. Humbert Y1 - 2005/12/01 UR - http://erj.ersjournals.com/content/26/6/986.abstract N2 - Pulmonary arterial hypertension (PAH) is a rare condition that occurs as a consequence of chronic obstruction of small pulmonary arteries due to endothelial cell, vascular smooth muscle cell and fibroblast dysfunction and proliferation 1. In recent years, major advances have been achieved in the understanding of PAH pathophysiology 1–7. It has been firmly demonstrated that pulmonary artery endothelial dysfunction leads to chronically impaired production of vasodilators, such as nitric oxide and prostacyclin, along with overexpression of vasoconstrictors such as endothelin-1 8–10. Moreover, genetic studies have shown that germline mutations in the gene coding for bone morphogenetic protein receptor type II (BMPR2) certainly play a critical role in a proportion of patients with familial and idiopathic PAH 2, 3. Immune disturbances are also believed to contribute to PAH 5. This is particularly clear in PAH related to connective tissue diseases 5, 11. In addition, there is a long standing association between autoimmunity and PAH of various origins including idiopathic PAH. However, it remains uncertain how autoimmune mechanisms contribute to the pathogenesis of PAH. In the current issue of the European Respiratory Journal, Nicolls et al. 7 review available data documenting the association of autoimmunity and PAH and speculate on the possible role of autoimmune injury in the pathogenesis of the disease. PAH is a common … ER -