CSF2 and autoimmune pulmonary alveolar proteinosis: She was diagnosed with autoimmune pulmonary alveolar proteinosis (aPAP) based on positive serum anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies and periodic acid-Schiff (PAS)-positive fluid accumulation in the alveoli identified on transbronchial lung biopsy (TBLB).