Pulmonary Alveolar Proteinosis

A 28 yo HIV-negative man presents with several month history of progressively worsening dyspnea and nonproductive cough.

His oxygen saturation was 75% on room air. On exam , he has digital clubbing. Lungs were CTAB.

Computed tomography of the chest (above) revealed diffuse ground-glass opacities with interlobular and intralobular septal thickening — a pattern described as crazy paving pattern. Bronchoscopy with lavage revealed milky-appearing fluid, with macrophages. BAL testing was positive on periodic acid–Schiff staining.

Pulmonary Alveolar Proteinosis

Pulmonary alveolar proteinosis (PAP) is a lung disease characterized by an abnormal intra-alveolar accumulation of surfactant-derived lipoproteinaceous material with a fairly vague and non-specific clinical presentation: dyspnea or a minimally-productive cough. It can be divided into 3 main categories: autoimmune, secondary, and congenital (least interesting…). The most common is the autoimmune which is due to an IgG to GM-CSF proteins. The next most common is secondary - or in response to an inflammatory insult: hematologic malignancies, inhalational disease, HIV, immunosuppression.