Pulmonary hypertension in the setting of interstitial lung disease: Approach to management and treatment. A consensus statement from the Pulmonary Vascular Research Institute's Innovative Drug Development Initiative—Group 3 Pulmonary Hypertension

To the editor,
Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare disease characterized by alveolar surfactant accumulation, progressive dyspnea, and hypoxemic respiratory insufficiency, and in some patients, secondary infections, pulmonary fibrosis, respiratory failure, and death.1 GM-CSF (granulocyte/macrophage colony-stimulating factor) autoantibodies cause aPAP by blocking GM-CSF signaling, which impairs alveolar macrophage functions including surfactant clearance.

The PERFECT study, a randomized, controlled, double-blind study of inhaled treprostinil in patients with COPD and associated pulmonary hypertension (PH-COPD) was a negative trial that was terminated early. The reason(s) for the negative outcome remains uncertain.

Tuberculosis (TB) may cause significant long-term cardiorespiratory complications, of which pulmonary vascular disease is most under-recognized. TB is rarely listed as a cause of pulmonary hypertension (PH) in most PH guidelines, yet PH may develop at various stages in the time course of TB, from active infection through to the post-TB period.

In pulmonary hypertension (PH) associated with chronic lung disease (CLD), identifying patients who would benefit from pulmonary vasodilators is a significant clinical challenge because the presence of PH is associated with poorer survival. This study evaluated the severity of pulmonary circulation impairment in patients with CLD-PH using pulmonary perfusion single-photon emission computed tomography/computed tomography (SPECT/CT).