Pulmonary Alveolar Proteinosis Medical Slides

Present the characteristic appearance: geographic areas of ground-glass opacity with superimposed interlobular septal thickening and intralobular lines, creating a "crazy paving" pattern. Emphasize that while highly suggestive of PAP, this pattern is not pathognomonic — it also occurs in lipoid pneumonia, pulmonary hemorrhage, PCP pneumonia, and acute ARDS. In PAP, the distribution is bilateral, symmetric, and geographic with sharp demarcation between affected and normal lung.

Present the procedure: performed under general anesthesia with double-lumen ETT, one lung ventilated while the other undergoes sequential filling (1 L warm saline) and drainage by gravity until effluent clears (typically 15-20 L total). Usually one side per session, repeated on the contralateral lung 1-2 weeks later. Efficacy: clinical improvement in 84-95% of patients, sustained remission in approximately 50% after single treatment. Complications: hypoxemia during procedure, pneumothorax, hydropneumothorax (rare).

Present the therapeutic evolution: WLL remains gold standard but is invasive and has limited availability. Inhaled recombinant GM-CSF: multiple phase 2 trials show clinical improvement in 60-70% of autoimmune PAP patients with minimal side effects. Rituximab (anti-CD20): targets B-cells producing anti-GM-CSF antibodies, case series show benefit in WLL-refractory patients. Plasmapheresis: reduces circulating anti-GM-CSF antibody titers, used as bridge or adjunct. No therapy has completed phase 3 RCT.