Circulating NEDD9 is increased in pulmonary arterial hypertension: A multicenter, retrospective analysis

BACKGROUND

Pulmonary arterial hypertension (PAH) is a highly morbid disease characterized by elevated pulmonary vascular resistance (PVR) and pathogenic right ventricular remodeling. Endothelial expression of the prometastatic protein NEDD9 is increased in fibrotic PAH arterioles, and NEDD9 inhibition decreases PVR in experimental PAH. We hypothesized that circulating NEDD9 is increased in PAH and informs the clinical profile of patients.

METHODS

Clinical data and plasma samples were analyzed retrospectively for 242 patients from 5 referral centers (2010–2017): PAH (n = 139; female 82%, 58 [48–67] years), non-PAH pulmonary hypertension (PH) (n = 54; female 56%, 63.4 ± 12.2 years), and dyspnea non-PH controls (n = 36; female 75%, 54.2 ± 14.0 years).

RESULTS

Compared with controls, NEDD9 was increased in PAH by 1.82-fold (p < 0.0001). Elevated NEDD9 correlated with PVR in idiopathic PAH (ρ = 0.42, p < 0.0001, n = 54), connective tissue disease (CTD)-PAH (ρ = 0.53, p < 0.0001, n = 53), and congenital heart disease–PAH (ρ = 0.68, p < 0.0001, n = 10). In CTD-PAH, NEDD9 correlated with 6-minute walk distance (ρ = −0.35, p = 0.028, n = 39). In contrast to the PAH biomarker N-terminal pro-brain natriuretic peptide (n = 38), NEDD9 correlated inversely with exercise pulmonary artery wedge pressure and more strongly with right ventricular ejection fraction (ρ = −0.41, p = 0.006, n = 45) in a mixed population. The adjusted hazard ratio for lung transplant–free survival was 1.12 (95% confidence interval [CI], 1.02–1.22, p = 0.01) and 1.75 (95% CI, 1.12–2.73, p = 0.01) per 1 ng/ml and 5 ng/ml increase in plasma NEDD9, respectively, by Cox proportional hazard model.

CONCLUSIONS

In PAH, plasma NEDD9 is increased and associates with key prognostic variables. Prospective studies that include hard end points are warranted to validate NEDD9 as a novel PAH biomarker.