Interstitial and alveolar autoimmune (90%) lung disorder causing antibodies against GM-CSF
Low levels GM-CSF limits macrophage maturation, which then can't catabolize surfactant
Results in filling of alveoli w/lipid-rich surfactant and protein
Risk Factors
Rare
Median age 39
M > F
History of smoking
Inhalation exposure (silica, toxic fumes)
Symptoms
Sub-acute, progressive sob over months
Non-productive cough
No response to antibiotics (initial treatment often directed towards infection)
Physical Exam Findings
If advanced, abnormal vital signs, respiratory distress
Inspiratory crackles
Treatments
Whole lung lavage (while intubated, sedated) to clear out alveoli
GM-CSF via sub-cu injection or inhalation
Tests
Characteristic "crazy paving" pattern on CT (ground glass opacities, interlobular septal thickening) - though not specific, as also seen w/ARDS, infection, pulmonary edema
Broncho-alveolar lavage w/milky fluid, PAS stain + (protein)