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Test Code PCHE1 Pseudocholinesterase, Total, Serum


Necessary Information


Patient's age and sex are required.



Specimen Required


Patient Preparation: For patients with prolonged apnea following surgery, wait at least 24 hours before obtaining specimen.

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.


Useful For

Monitoring exposure to organophosphorus insecticides and herbicides

 

Monitoring patients with liver disease, particularly those undergoing liver transplantation

 

Identifying patients who are homozygous or heterozygous for an atypical gene and have low levels of pseudocholinesterase

 

This test is not useful for the differential diagnosis of jaundice.

Method Name

Colorimetric Assay

Reporting Name

Pseudocholinesterase, Total, S

Specimen Type

Serum

Specimen Minimum Volume

0.25 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  365 days
  Ambient  24 hours

Reference Values

Males

5320-12,920 U/L

 

Females

0-15 years: 5320-12,920 U/L

16-39 years: 4260-11,250 U/L

40-41 years: 5320-12,920 U/L

≥42 years: 5320-12,920 U/L

Note: Females aged 18-41 years who are pregnant or taking hormonal contraceptives, the reference interval is 3650-9120 U/L.

Interpretation

Patients with normal pseudocholinesterase (PCHE) activity show 70% to 90% inhibition by dibucaine, while patients homozygous for the abnormal allele show little or no inhibition (0%-20%) and usually low levels of enzyme.

 

Heterozygous patients have intermediate PCHE levels and response to inhibitors.

 

The atypical gene is inherited in an autosomal recessive pattern. In a positive patient, family members should be tested.

 

Decreasing or low levels may indicate exposure to organophosphorus insecticides or herbicides if liver disease and an abnormal allele have been ruled out.

Clinical Reference

1. Soliday FK, Conley YP, Henker R. Pseudocholinesterase deficiency: A comprehensive review of genetic, acquired, and drug influences. AANA J. 2010;78:313-320

2. Robles A, Michael M, McCallum R. Pseudocholinesterase deficiency: What the proceduralist needs to know. Am J Med Sci. 2019;357(3):263-267. doi:10.1016/j.amjms.2018.11.002

3. Lurati AR. Organophosphate exposure with pseudocholinesterase deficiency. Workplace Health and Saf. 2013;61(6):243-245. doi:10.1177/216507991306100602

4. den Blaauwen DH, Poppe WA, Tritschler W. Cholinesterase (EC 3.1.1.8) with butyrylthiocholine-iodide as substrate: References depending on age and sex with special reference to hormonal effects and pregnancy. J Clin Chem Clin Biochem. 1983;21:381-386

Day(s) Performed

Monday through Friday

Report Available

Same day/1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

82480

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PCHE1 Pseudocholinesterase, Total, S 2098-2

 

Result ID Test Result Name Result LOINC Value
PCHE1 Pseudocholinesterase, Total, S 2098-2