Liver findings in Niemann-Pick disease type C.

A complex analysis of liver from a series of eight cases of Niemann-Pick disease type C showed practically generalized storage of glycolipids and phosphoglycerides by chemical and histochemical techniques. In six of the eight cases the storage process was of low degree, barely recognizable by routine histology, but well recognizable by histochemistry and electron-microscopy. In two cases it was marked and led to early functional impairment of the liver. Changes in various enzyme activities and in ultrastructural features of the storage process are described. Sphingomyelin was found to participate to a very low low degree and its accumulation was not proportional to the extent of overall storage. In two cases with prominent involvement of the liver normal levels of sphingomyelin were found. In other cases sphingomyelin was found, by lipid histochemistry, to be stored only in macrophages. To stress that the storage process in Niemann-Pick disease type C is qualitatively different a comparison was made with liver findings in sphingomyelinase-deficient patients. This feature is of practical as well as theoretical importance.