Pulmonary Alveolar Proteinosis: Is the Focus in Treatment Shifted From ‘Physical’ to ‘Pharmacological’?

Pulmonary alveolar proteinosis (PAP) is a rare syndrome characterized by accumulation of surfactant material in pulmonary alveoli resulting in progressive dyspnoea, hypoxemia, with a risk of respiratory failure and early death [1][2][3].PAP is caused by various different diseases and, depending on the cause, is divided into several types of disorders.Primary PAP is driven by disruption of the signalling pathway of granulocyte-macrophage colony-stimulating factor (GM-CSF) resulting in dysfunction of alveolar macrophages, but secondary PAP occurs because of underlying diseases and conditions that reduce the number and/or functions of alveolar macrophages.Some diseases are known to cause secondary PAP, like blood and non-blood haematological malignancies, immune deficiencies, chronic inflammation, occupational or environmental exposures, chronic infections, and disorders of lung surfactant metabolism.