Abstract
Idiopathic pulmonary arterial hypertension (IPAH) is characterized by pulmonary vascular remodeling. We have reported that high-dose prostaglandin I(2) (PGI(2)) therapy markedly improved hemodynamics in IPAH patients and that PGI(2) induced apoptosis of pulmonary artery smooth muscle cells obtained from IPAH patients. PGI(2) is thought to have reverse remodeling effects, although it has not been histologically confirmed. In a case series, we examined the reverse pulmonary vascular remodeling effects of PGI(2) in lung tissues obtained from an IPAH patient treated with high-dose PGI(2) and an IPAH patient not treated with PGI(2). Apoptotic cells were detected in small pulmonary arteries of the IPAH patient treated with high-dose PGI(2) but not in those from the IPAH patient not treated with PGI(2). Media of peripheral pulmonary arteries were thick in the IPAH patient not treated with PGI(2). On the other hand, media of peripheral pulmonary arteries were thin in the IPAH patient treated with high-dose PGI(2). The single case report suggested that high-dose PGI(2) therapy has the potential for reverse pulmonary vascular remodeling by induction of apoptosis and reduction of medial hypertrophy. Accumulation of cases is needed for the application to generalized effect of high-dose PGI(2). .