Test Catalog

Test Id : LIPA1

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Lipoprotein(a), Serum

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Cardiovascular disease (CVD) risk refinement in patients with moderate or high risk based on conventional risk factors or patients with clinical suspicion of residual CV risk not identified by other lipid parameters

Method Name
A short description of the method used to perform the test

Immunoturbidimetric Assay

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Lipoprotein(a), S

Aliases
Lists additional common names for a test, as an aid in searching

Lipoprotein (a), S

Lipoprotein a

LP "little-A"

Lp(a) apoprotein

Specimen Type
Describes the specimen type validated for testing

Serum

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial. Send refrigerated.

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Cardiovascular Test Request Form (T724)

-General Test Request (T239)

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.5 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject
 

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
Frozen 30 days
Ambient 24 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Cardiovascular disease (CVD) risk refinement in patients with moderate or high risk based on conventional risk factors or patients with clinical suspicion of residual CV risk not identified by other lipid parameters

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Lipoprotein (a) consists of a low-density lipoprotein (LDL) particle that is covalently bound to an additional protein, apolipoprotein (a) [Apo(a)]. Apo(a) has high sequence homology with the coagulation factor plasminogen, and like LDL, Lp(a) contains apolipoprotein B100 (ApoB). Thus, Lp(a) is both proatherogenic and prothrombotic.

 

Lp(a) is an independent risk factor for coronary heart disease (CHD), ischemic stroke, and aortic valve stenosis. Lp(a) has been referred to as "the most atherogenic lipoprotein". The mechanism of increased risk is unclear but most likely involves progression of atherosclerotic stenosis via intimal deposition of cholesterol and promotion of thrombosis via homology to plasminogen.

 

Accurate immunochemical measurement of Lp(a) is complicated by the heterogeneity of Lp(a) molecular size. Due to the large number of polymorphisms (varying number of kringle domain repeats in the Apo[a] protein) in the population, any given individual can have an Apo(a) protein between 240 to 800 kDa. This heterogeneity leads to inaccuracies in all immunoassay. In addition, the degree of atherogenicity of the Lp(a) particle may depend on the molecular size of the Lp(a)-specific protein. However, the measurement of Lp(a) using immunoassays calibrated to molar units is recommended to minimize assay inaccuracies caused by Apo(a) isoform size.

 

Serum concentrations of Lp(a) are related to genetic factors, specifically the expression of Apo(a), and are largely unaffected by diet, exercise, and lipid-lowering pharmaceuticals. However, in a patient with additional modifiable CHD risk factors, more aggressive therapy to normalize these factors may be indicated if the Lp(a) value is also increased. In cases of extremely elevated Lp(a), lipoprotein apheresis may be considered.

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.

> or =18 years: <75 nmol/L

Values > or =75 nmol/L may suggest increased risk of coronary heart disease.

Values > or =175 nmol/L is considered a risk-enhancing factor for cardiovascular disease by several professional societies. Clinician-patient discussion of therapeutic strategy is warranted.

 

Reference values have not been established for patients who are less than 18 years of age.

Interpretation
Provides information to assist in interpretation of the test results

Lipoprotein (a) (Lp[a]) concentrations of 75 nmol/L and above is linearly related to increased risk of cardiovascular events independent of conventional risk markers.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Epidemiologic studies have shown lipoprotein (a) (Lp[a]) concentrations are lowest in non-Hispanic white, Chinese, and Japanese populations. The Hispanic population has a slightly higher median Lp(a) concentration, and, in the African American population, the median Lp(a) serum concentration is approximately 2 times higher than in the white population.

 

In very rare cases, gammopathy, type IgM (Waldenstrom macroglobulinemia) in particular, may cause unreliable results.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Emerging Risk Factors Collaboration, Erqou S, Kaptoge S, et al: Lipoprotein(a) concentration and the risk of coronary heart disease, stroke, and nonvascular mortality. JAMA. 2009 Jul 22;302(4):412-423

2. Tsimikas S: A test in context: Lipoprotein(a): Diagnosis, prognosis, controversies, and emerging therapies. J Am Coll Cardiol. 2017 Feb 14;69(6):692-711. doi: 10.1016/j.jacc.2016.11.042

3. Marcovina SM, Koschinsky ML, Albers JJ, Skarlatos S: Report of the National Heart, Lung, and Blood Institute Workshop on Lipoprotein (a) and Cardiovascular Disease: recent advances and future directions. Clin Chem. 2003 Nov;49(11):1785-1796

4. Wilson DP, Jacobson TA, Jones PH, et al: Use of Lipoprotein(a) in clinical practice: A biomarker whose time has come. A scientific statement from the National Lipid Association. J Clin Lipidol. 2019 May-Jun;13(3):374-392. doi: 10.1016/j.jacl.2019.04.010

Method Description
Describes how the test is performed and provides a method-specific reference

This test is a particle enhanced immunoturbidimetric assay. Human lipoprotein (a) (Lp[a]) agglutinates with the latex particles coated with anti-Lp(a) antibodies.(Package insert: Tina-quant Lipoprotein(a) Gen.2 reagent. Roche Diagnostics; V2.0, 01/2015)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 3 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

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 instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

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 Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

83695

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
LIPA1 Lipoprotein(a), S 43583-4
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
LIPA1 Lipoprotein(a), S 43583-4

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | PHP Pdf | CMS Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports