Abstract 20267: Diminished Levels of Circulating Bone Morphogenetic Protein 9 Identify Pulmonary Arterial Hypertension Associated With Liver Disease

Background: Dysregulated bone morphogenetic protein (BMP) signaling is thought to contribute to the pathogenesis of pulmonary arterial hypertension (PAH). BMP9 can be detected in the circulation at physiologically active concentrations, and is thought to serve as a vascular endothelial quiescence factor. Aim: We hypothesized that circulating levels of BMP9 might be associated with altered endothelial homeostasis, and could help predict the presence of PAH or distinguish between PAH of distinct etiologies. Methods: Circulating levels of BMP9, and its biological inhibitor, soluble Endoglin (sEng), were measured in the plasma of 96 patients with various etiologies of pulmonary hypertension and 28 healthy individuals using enzyme-linked immunoassays. Results: Patients with Group I PAH (n=44) had significantly lower levels of BMP9 compared to healthy individuals (188 ± 22 pg/mL vs 254 ± 17 pg/mL, mean ± SEM, p=0.001). BMP9 was significantly decreased in PAH associated with connective tissue disease (p=0.02), but was most profoundly decreased in patients with portopulmonary hypertension (82 ± 27 pg/mL, p