NPPB and pulmonary arterial hypertension: Michelfelder et al. [15] compared SSc-PAH-ILD (n = 24) patients with SSc-PAH patients (n = 27), and did not find a difference in hemodynamic parameters, NT-proBNP levels, FVC/DLCO ratio, 6 MW, WHO function class and scleroderma-specific autoantibody levels between two groups, but a decreased survival rate in SSc-PAH-ILD patients.