Autoimmune Pulmonary Alveolar Proteinosis

Autoimmune Pulmonary Alveolar Proteinosis (aPAP) is a rare, severe lung disease (7–10 per million) where autoantibodies block GM-CSF signaling, causing surfactant buildup in the alveoli. Affecting mostly adults aged 30–60, it leads to dyspnea, cough, and hypoxemic respiratory failure. Whole-lung lavage is the standard treatment. 

Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare lung disease characterized by a gradual onset of shortness of breath (dyspnea) and persistent, often dry, cough. It occurs when autoantibodies block the clearance of surfactant, causing it to build up in the air sacs (alveoli). Common symptoms include: 

Autoimmune Pulmonary Alveolar Proteinosis (aPAP) is caused by the immune system producing autoantibodies (anti-GM-CSF antibodies) that block granulocyte-macrophage colony-stimulating factor (GM-CSF). This prevents alveolar macrophages from clearing lung surfactant, leading to protein buildup. It is the most common form, often affecting adults aged 30-50, with smoking as a key risk factor. 

It is generally not possible to prevent autoimmune Pulmonary Alveolar Proteinosis (aPAP), as it is a disease driven by the body’s own immune system producing autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF). 

Autoimmune Pulmonary Alveolar Proteinosis (aPAP) is diagnosed by identifying specific Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) antibodies in the blood and characteristic “crazy paving” patterns on high-resolution CT scans. Bronchoalveolar lavage (BAL) showing PAS-positive material is often used for confirmation. 

The prognosis for Autoimmune Pulmonary Alveolar Proteinosis (aPAP) is generally favorable, with a 5-year survival rate of approximately 95% due to effective treatments like Whole Lung Lavage (WLL). While it is a chronic, non-curable, and potentially life-threatening condition, most patients achieve stability or significant improvement. 

Autoimmune Pulmonary Alveolar Proteinosis (aPAP) is treated primarily with Whole Lung Lavage (WLL) to wash out accumulated proteinaceous surfactant. For milder to moderate cases, inhaled GM-CSF replacement therapy is now a preferred, less invasive first-line approach. For severe cases, WLL is standard, with third-line options including rituximab, plasmapheresis, or lung transplantation.