Test ID: LPC
Lysophosphatidylcholine, Plasma
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Detecting lecithin cholesterol acyltransferase deficiency
Method Name A short description of the method used to perform the test
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Lyso-PC
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Fasting-overnight (12-14 hours)
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross reject |
| Lipemia | Mild OK; Gross OK |
| Icterus | Mild OK; Gross OK |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma EDTA | Frozen | |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Plasma lysophosphatidylcholine (LPC) concentration is diminished in patients with lecithin cholesterol acyltransferase (LCAT) deficiency. LCAT is the enzyme responsible for synthesizing the majority of cholesteryl esters in serum by transferring fatty acid from phosphatidylcholine to the 3-hydroxyl group of cholesterol. It is believed that LCAT regulates the transport of cholesterol between extravascular and intravascular pools. In the theoretical pathway known as reverse cholesterol transport, cholesterol is moved from peripheral tissues to the liver for catabolism. The esterification of cholesterol by LCAT in serum serves to maintain a chemical concentration gradient for unesterified cholesterol between peripheral tissue cells and the serum.
LPC additionally has been shown to play a functional role in various biological processes including cell migration, cell proliferation, angiogenesis, and inflammation. LPC stimulates monocyte chemoattractant protein-1 and induces expression of adhesion molecules on the surface of endothelial cells and, thus, may play a role in coronary atherogenesis.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
16:0 LYSOPHOSPHATIDYLCHOLINE
> or =16 years: > or =62 mcmol/L
18:0 LYSOPHOSPHATIDYLCHOLINE
> or =16 years: > or =20 mcmol/L
Reference values have not been established for patients that are <16 years of age.
Interpretation Provides information to assist in interpretation of the test results
Decreased values for 16:0 lysophosphatidylcholine (LPC) and 18:0 LPC are consistent with lecithin cholesterol acyltransferase deficiency.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
No significant cautionary statements
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Santamarina-Fojo S, Hoeg JM, Assman G, Brewer HB Jr: Lecithin cholesterol acyltransferase deficiency and fish eye disease. In The Metabolic and Molecular Basis of Inherited Disease. 8th edition. Edited by C Scriver, A Beaudet, W Sly, et al. New York, McGraw-Hill Book Company, 2001, pp 2817-2833
2. Tselepis AD, Chapman JM: Inflammation, bioactive lipids and atherosclerosis: potential roles of a lipoprotein-associated phospholipase A2, platelet-activating factor-acetylhydrolase. Atheroscler Suppl 2002 Dec;3(4):57-68
Method Description Describes how the test is performed and provides a method-specific reference
Plasma is extracted with butanol after the addition of 17:0 lysophosphatidylcholine (LPC) as internal standard. After vortexing and centrifugation, the upper phase is collected, evaporated in a warm water bath using nitrogen, and reconstituted in methanol. Analysis is by electrospray liquid chromatography-tandem mass spectrometry (LC-MS/MS) operating in the positive mode and using selected-reaction monitoring. 16:0 and 18:0 LPCs are quantitated using 17:0 LPC as internal standard from calibration over a concentration range of 0.1 mcM to 5.0 mcM. (Lacey JM, Magera MJ, Matern D, et al: Rapid quantitative determination of lysophosphatidylcholine by liquid chromatography tandem mass spectrometry [LC-MS/MS]. J Am Soc Mass Spec 2003;13[5]S1:26S)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Varies; 11 a.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
83789
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| 83399 | 16:0 Lysophosphatidylcholine | In Process |
| 23618 | 18:0 Lysophosphatidylcholine | In Process |
| 23859 | Interpretation | 59462-2 |
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