Pulmonary arterial hypertension in connective tissue disorders: Pathophysiology and treatment:

Pulmonary arterial hypertension (PAH) is a serious complication of connective tissue disorders (CTDs), and CTD-PAH is the second cause of PAH after the idiopathic form. PAH is characterized by increased pulmonary arterial pressure and pulmonary vascular resistance, which can lead to right heart failure and death. About 90% of CTD-PAH cases are associated with systemic sclerosis (SSc, 74%), mixed connective tissue disease (MCTD, 8%) or systemic lupus erythematosus (SLE, 8%). CTD-PAH has also been reported, albeit rarely, in Sjogren syndrome, inflammatory idiopathic myopathies and rheumatoid arthritis. As for idiopathic PAH, the impaired production of vasoactive mediators such as nitric oxide and prostacyclin, and the increased production of vasoconstrictors and proliferative mediators such as endothelin-1, affect the vascular tone and promote vascular remodeling. Moreover, there is growing evidence suggesting that inflammation and autoimmunity may contribute to the genesis and progression of CTD-PAH, espec...