title: Extended use of a selective inhibitor of acid lipase for the diagnosis of Wolman disease and cholesteryl ester storage disease.
abstract: Lysosomal acid lipase (LAL) deficiency produces two well defined inborn disorders, Wolman disease (WD) and cholesteryl ester storage disease (CESD). WD is a severe, early-onset condition involving massive storage of triglycerides and cholesteryl esters in the liver, with death usually occurring before one year of life. CESD is a more attenuated, later-onset disease that leads to a progressive and variable liver dysfunction. Diagnosis of LAL deficiency is mainly based on the enzyme assay of LAL activity in fibroblasts. Recently, a selective acid lipase inhibitor was used for the determination of enzyme activity in dried-blood filter paper (DBFP) samples. To extend and to validate these studies, we tested LAL activity with selective inhibition on DBFP samples, leukocytes and fibroblasts. Our results showed a clear discrimination between patients with LAL deficiency and healthy controls when using DBFP, leukocytes or fibroblasts (p<0.001). Deficiency of LAL was also demonstrated in individuals referred to our laboratory with suspected clinical diagnosis of WD, CESD, and Niemann-Pick type B. We conclude that the assay of LAL using selective inhibitor is a reliable and useful method for the identification of LAL deficiency, not only in DBFP samples but also in leukocytes and fibroblasts. This is important as enzyme replacement therapy for LAL deficiency is currently being developed, making the correct diagnosis a critical issue.
authors: Medical Genetics Service, HCPA, Porto Alegre, Brazil; Department of Genetics, UFRGS, Porto Alegre, Brazil. Electronic address: gecivallero@yahoo.com.
authors: G
authors: G
authors: Civallero
authors: Medical Genetics Service, HCPA, Porto Alegre, Brazil.
authors: J
authors: J
authors: De Mari
authors: INAGEMP, Porto Alegre, Brazil.
authors: C
authors: C
authors: Bittar
authors: Medical Genetics Service, HCPA, Porto Alegre, Brazil.
authors: M
authors: M
authors: Burin
authors: Medical Genetics Service, HCPA, Porto Alegre, Brazil; Department of Genetics, UFRGS, Porto Alegre, Brazil; INAGEMP, Porto Alegre, Brazil.
authors: R
authors: R
authors: Giugliani
mesh_terms: D002219:Carbamates / Q000494:pharmacology*; D002478:Cells, Cultured; D015217:Cholesterol Ester Storage Disease / Q000175:diagnosis*; D059788:Dried Blood Spot Testing; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D007962:Leukocytes / Q000201:enzymology; D008049:Lipase / Q000037:antagonists & inhibitors*; D008099:Liver / Q000201:enzymology; D009542:Niemann-Pick Diseases / Q000175:diagnosis; D002787:Sterol Esterase / Q000037:antagonists & inhibitors; D013830:Thiadiazoles / Q000494:pharmacology*; D015223:Wolman Disease / Q000175:diagnosis*
chemical_list: D002219:Carbamates; D013830:Thiadiazoles; C576036:lalistat 2; D002787:Sterol Esterase; D008049:Lipase
keywords: Cholesteryl ester storage disease; Dried-blood filter paper; Enzyme assay; Fibroblasts; Leukocytes; Lysosomal acid lipase; Selective acid lipase inhibitor; Wolman disease