TABLE 2

Clinical features of Hermansky–Pudlak syndrome (HPS) pulmonary fibrosis and idiopathic pulmonary fibrosis (IPF)

	HPS-1 or HPS-4 pulmonary fibrosis	HPS-2 pulmonary fibrosis	IPF
Onset of pulmonary symptoms	Middle age	Children or young adults	>50 years of age
Acute exacerbations	Yes	Unknown	Yes
Oculocutaneous albinism	Yes	Yes	No
Nystagmus	Yes	Yes	No
Excessive bleeding	Yes	Yes	No
HRCT scan finding of ground-glass opacification	Yes	Yes	No
Type II epithelial cell enlargement	Yes	Yes	No
Giant lamellar bodies	Yes	Yes	No
Foamy alveolar macrophages	Yes	Unknown	No
Ceroid lipofuscin tissue deposition	Yes	Yes	No
Pulmonary histopathology	UIP, NSIP, DAD	UIP, NSIP, DIP	UIP

HRCT: high-resolution computed tomography; UIP: usual interstitial pneumonia; NSIP: nonspecific interstitial pneumonia; DAD: diffuse alveolar damage; DIP: desquamative interstitial pneumonitis.