Abnormal circulating enzyme concentration or activity Reduced lysosomal acid lipase activity 2017-06-29T11:32:13Z Reduced leukocyte acid lipase activity Reduction in the activity of lysosomal acid lipase (LAL) in the blood. Lysosomal lipase activity is measured. LAL hydrolyzes cholesteryl esters derived from cell internalization of plasma lipoproteins. Samples from patients with Wolman Disease display extremely low or unmeasurable levels of lysosomal acid lipase (LAL) activity. Samples from patients with cholesteryl ester storage disease can display residual activities in the 5 to ten percent range.