The urine from patients with peritonitis as a rich source for purifying human acid sphingomyelinase and other lysosomal enzymes.

Milligram amounts of human acid sphingomyelinase (EC 3.1.4.12) were purified to 95% homogeneity using urine from patients with acute peritonitis. The activity of this enzyme is elevated more than 200-times in the urine of these patients. To a lesser extent, levels of some other lysosomal hydrolases are also elevated.