Test Code LALB Lysosomal Acid Lipase, Blood
Useful For
Evaluation of patients with a clinical presentation suggestive of lysosomal acid lipase deficiency using blood specimens
This test is not useful to determine carrier status for cholesteryl ester storage disease or Wolman disease.
Special Instructions
Reporting Name
Lysosomal Acid Lipase, BSpecimen Type
Whole bloodSpecimen Required
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD) or green top (sodium heparin)
Specimen Volume: 2 mL
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole blood | Refrigerated (preferred) | 7 days | |
Ambient | 7 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Clinical Information
Deficiency of lysosomal acid lipase (LAL) results in 2 clinically distinct phenotypes, Wolman disease (WD) and cholesteryl ester storage disease (CESD). Both phenotypes follow an autosomal recessive inheritance pattern and are caused by variant in the LIPA gene.
WD, the early-onset phenotype of LAL deficiency, is a lipid storage disorder characterized by vomiting, diarrhea, failure to thrive, abdominal distension, hepatosplenomegaly, and liver failure. Enlarged adrenal glands with calcification, a classic finding in WD, can lead to adrenal cortical insufficiency. Unless successfully treated, survival is rare beyond infancy.
CESD, the late-onset phenotype of LAL deficiency, is clinically variable with patients presenting at any age with progressive hepatomegaly and often splenomegaly, serum lipid abnormalities, and elevated liver enzymes. In childhood, patients can also present with failure to thrive and delayed milestones. Common features include premature atherosclerosis leading to coronary artery disease and strokes, liver disease of varying severity, and organomegaly. Lipid deposition in the intestinal tract can lead to diarrhea and weight loss.
CESD is likely underdiagnosed and frequently diagnosed incidentally after liver pathology reveals findings similar to nonalcoholic fatty liver disease or nonalcoholic steatohepatitis. Birefringent cholesteryl ester crystals in hepatocytes or Kupffer cells in fresh-frozen tissues are visualized under polarized light and pathognomonic.
Enzyme replacement therapy (sebelipase alfa) was recently approved for both WD and CESD and is now clinically available.
Reference Values
≥21.0 nmol/h/mL
Interpretation
Enzyme activity below 1.5 nmol/h/mL in properly submitted samples is consistent with lysosomal acid lipase deficiency: Wolman disease or cholesteryl ester storage disease.
Normal results (≥21.0 nmol/h/mL) are not consistent with lysosomal acid lipase deficiency.
Cautions
No significant cautionary statements
Day(s) Performed
Friday
Report Available
8 to 15 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82657
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
LALB | Lysosomal Acid Lipase, B | 73958-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
62954 | Lysosomal Acid Lipase, B | 73958-1 |
36339 | Reviewed By | 18771-6 |
36338 | Interpretation (LALB) | 59462-2 |
Method Name
Fluorometric Enzyme Assay
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Biochemical Genetics Patient Information (T602)
3. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen: