Niemann-Pick type C1 (NPC1) disease arises from a mutation inactivating NPC1 
protein that normally moves unesterified cholesterol from the late 
endosomal/lysosomal complex of cells to the cytosolic compartment for 
processing. As a result, cholesterol accumulates in every tissue of the body 
causing liver, lung, and CNS disease. Treatment of the murine model of this 
disease, the npc1 mouse, s.c. with β-cyclodextrin (4000 mg/kg) one time each 
week normalized cellular cholesterol metabolism in the liver and most other 
organs. At the same time, the hepatic dysfunction seen in the untreated npc1 
mouse was prevented. The severity of cerebellar neurodegeneration also was 
ameliorated, although not entirely prevented, and the median lifespan of the 
animals was doubled. However, in contrast to these other organs, lung showed 
progressive macrophage infiltration with development of lipoid pneumonitis. 
These studies demonstrated that weekly cyclodextrin administration overcomes the 
lysosomal transport defect associated with the NPC1 mutation, nearly normalizes 
hepatic and whole animal cholesterol pools, and prevents the development of 
liver disease. Furthermore, this treatment slows cerebellar neurodegeneration 
but has little or no effect on the development of progressive pulmonary disease.