Recent advances in the diagnosis and management of pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare lung disorder characterized by the accumulation of surfactant-derived material in the alveolar spaces due to impaired macrophage function. Autoimmune PAP (aPAP) is caused by neutralizing autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF) and accounts for over 90% of cases. PAP causes respiratory symptoms and, in severe cases, respiratory failure necessitating lung transplantation. Early diagnosis and intervention are crucial. This narrative review is based on a PubMed literature search last performed 30 March 2025. This review examines the pathophysiology, diagnosis, and treatment of PAP. We focus on GM-CSF autoantibody testing and bronchoalveolar lavage (BAL) for diagnosis and treatment modalities including whole lung lavage (WLL) and inhaled GM-CSF therapy. The use of rituximab, plasmapheresis, and lung transplantation for refractory cases is also discussed. The advent of WLL and GM-CSF has advanced the care of patients with aPAP. However, challenges still remain in managing treatment-resistant cases, and for patients with non-autoimmune forms of PAP where treatment options are more limited. Further research is needed to optimize therapeutic strategies, especially for patients who do not respond to first-line treatments. Timely diagnosis and early intervention remain essential for improving patient outcomes.