Epidemiologic features:
(1) male
(2) familial
(3) Caucasian
Environmental exposures:
(1) cigarette smoking
(2) organic dusts (aluminum, silica, titanium, nitrogen dioxide)
Immunosuppression or autoimmunity:
(1) lung transplant
(2) immunoglobulin deficiency
(3) hematologic malignancies (AML)
(4) autoantibodies against granulocyte-macrophage colony stimulating factor (GM-CSF)
Uncertain (special care needs to be taken to exclude false positive diagnosis):
(1) pulmonary amyloidosis (amyloid protein may mimic PAP globules)
(2) opportunistic infections (may represent complicating conditions rather than preceding events):
(2a) Nocardia species
(2b) Pneumocystis carinii (PCP)
(2c) cytomegalovirus (CMV)
(2d) Histoplasma capsulatum
(2e) Mycobacterium species (tuberculosis and nontuberculous)
