Test Catalog

Test Id : LBCS

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Labile Bound Copper, Serum

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Overview

Test Catalog

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

May be useful in the evaluation of copper-related disorders, including Wilson disease

Additional Tests
Lists tests that are always performed, at an additional charge, with the initial tests.

Test Id Reporting Name Available Separately Always Performed
CUS1 Copper, S Yes Yes

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

After a labile bound copper serum result is obtained, a total copper serum test will be performed at an additional charge. The labile bound copper concentration will be divided by the total copper concentration to calculate the labile bound copper fraction result.

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

Inductively-Coupled Plasma Mass Spectrometry (ICP-MS)

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

Labile Bound Copper, S

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

Copper (Cu)

Cu (Copper)

Kaiser Fleischer Ring

Wilson's Disease

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

After a labile bound copper serum result is obtained, a total copper serum test will be performed at an additional charge. The labile bound copper concentration will be divided by the total copper concentration to calculate the labile bound copper fraction result.

Specimen Type
Describes the specimen type validated for testing

Serum

Ordering Guidance

If CUS1 / Copper, Serum is ordered with this test, it will be canceled, as copper testing will be automatically added as a part of this test order.

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

Patient Preparation: High concentrations of gadolinium and iodine are known to potentially interfere with most inductively coupled plasma mass spectrometry-based metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for at least 96 hours.

Supplies:

-Metal Free Specimen Vial (T173)

-Metal Free B-D Tube (No Additive), 6 mL (T184)

Collection Container/Tube: 6-mL Plain, royal blue-top Vacutainer plastic trace element blood collection tube

Submission Container/Tube: 7-mL Metal-free, screw-capped, polypropylene vial

Specimen Volume: 0.75 mL

Collection Instructions:

1. For complete instructions, see Metals Analysis Specimen Collection and Transport.

2. Allow the specimen to clot for 30 minutes; then centrifuge the specimen to separate serum from the cellular fraction.

3. Remove the stopper. Carefully pour specimen into metal-free, polypropylene vial, avoiding transfer of the cellular components of blood. Do not insert a pipet into the serum to accomplish transfer, and do not ream the specimen with a wooden stick to assist with serum transfer.

4. Freeze sample on dry ice immediately after pouring off the serum.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

0.5 mL

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

Gross hemolysis OK
Gross lipemia OK
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 Frozen 28 days METAL FREE

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

May be useful in the evaluation of copper-related disorders, including Wilson disease

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

After a labile bound copper serum result is obtained, a total copper serum test will be performed at an additional charge. The labile bound copper concentration will be divided by the total copper concentration to calculate the labile bound copper fraction result.

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

Copper (Cu) is an important trace element that is associated with a number of metalloproteins. Copper in biological material is complexed with proteins, peptides, and other organic ligands. The majority of copper in plasma is bound to the enzyme ceruloplasmin, a copper-dependent multifunction oxidase enzyme. Up to 90% of copper exported from the liver into peripheral blood is tightly protein bound. The remaining copper fraction is often referred to as "free" copper, however a more accurate description is labile bound copper (LBC), as it is not truly circulating freely but is loosely bound to various smaller proteins, including albumin, transcuprein, tetrapeptides, and other amino acids.

 

This test involves measurement of both the LBC concentration and total copper. The LBC will be divided by the measured total copper concentration to calculate a LBC fraction result. The LBC fraction (%) may be more useful than LBC in some disease states, such as Wilson disease, as it represents the fraction of LBC normalized against potential variation in total copper burden.

 

Low serum copper, most often due to excess iron or zinc ingestion and infrequently due to dietary copper deficit, may result in altered growth and in impaired erythropoiesis. Low total serum copper is also observed in hepatolenticular degeneration (Wilson disease) due to a decrease in the synthesis of ceruloplasmin and allelic variances in cellular metal ion transporters. In Wilson disease, the albumin-bound copper may actually be increased, but ceruloplasmin-bound copper is low, resulting in low serum copper. However, during the acute phase of Wilson disease (fulminant hepatic failure), ceruloplasmin and copper levels may be normal; in this circumstance, hepatic inflammation causes increased release of ceruloplasmin. It is useful to relate the degree of liver inflammation to ceruloplasmin and copper (see the following discussion on hypercupremia). Significant hepatic inflammation with normal ceruloplasmin and copper suggest acute Wilson disease.

 

As WD is characterized by a loss of ceruloplasmin-copper binding function, the concentration of non-ceruloplasmin bound labile copper (NCC) is an attractive target as a diagnostic aid. NCC has been historically estimated by the following formula: NCC = total serum copper (mcg/dL) - [3.15 x ceruloplasmin (mcg/dL)]. This calculated estimate has limitations, as it is difficult to directly measure ceruloplasmin, and assumes that all available ceruloplasmin is fully saturated with copper. As such, a clinical assay that can directly quantify the proportion of "free" or labile bound (LBC fraction) of total copper in serum may be preferable. While measurement of LBC fraction has been shown to be a promising diagnostic tool for Wilson disease, it may be applicable to other copper-related disorders as well.

 

Additional disorders associated with decreased serum copper concentrations include malnutrition, hypoproteinemia, malabsorption, nephrotic syndrome, Menkes disease, copper toxicity, and megadosing of zinc-containing vitamins (zinc interferes with normal copper absorption from the gastrointestinal [GI] tract). Hypercupremia is found in primary biliary cholangitis (formerly primary biliary cirrhosis), primary sclerosing cholangitis, hemochromatosis, malignant diseases (including leukemia), thyrotoxicosis, and various infections. Serum copper concentrations are also elevated in patients taking contraceptives or estrogens and during pregnancy. Since the GI tract effectively excludes excess copper, it is the GI tract that is most affected by copper ingestion. Increased copper serum concentration, LBC copper, and LBC fraction alone do not directly indicate copper toxicity.

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.

Labile Bound Copper: <105 ng/mL

 

Labile Bound Copper Fraction:

Males: <10.5 %

Females: <8.1 %

 

Copper, Total:

0-2 months: 40-140 mcg/dL

3-6 months: 40-160 mcg/dL

7-9 months: 40-170 mcg/dL

10-12 months: 80-170 mcg/dL

13 months-10 years: 80-180 mcg/dL

11-17 years: 75-145 mcg/dL

Males:

> or =18 years: 73-129 mcg/dL

Females:

> or =18 years: 77-206 mcg/dL

Interpretation
Provides information to assist in interpretation of the test results

This test measures the labile bound copper (LBC) in serum and calculates the fraction (%) of labile bound copper to total copper (LBC fraction).

 

Serum copper results below the normal range and LBC fraction above the normal range are associated with Wilson disease. Abnormal total copper and LBC fraction may also be associated with a variety of other copper-related disorders (see Clinical Information).

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
Recommendations for in-depth reading of a clinical nature

1. Woimant F, Djebrani-Oussedik N, Poujois A. New tools for Wilson's disease diagnosis: exchangeable copper fraction. Ann Transl Med. 2019;7(Suppl 2):S70. doi:10.21037/atm.2019.03.02

2. McMillin GA, Travis JJ, Hunt JW. Direct measurement of free copper in serum or plasma ultrafiltrate. Am J Clin Pathol. 2009;131(2):160-5. doi:10.1309/AJCP7Z9KBFINVGYF

3. Quarles CD Jr, Macke M, Michalke B, et al. LC-ICP-MS method for the determination of "extractable copper" in serum. Metallomics. 2020;12(9):1348-1355

4. Shribman S, Marjot T, Sharif A, et al. Investigation and management of Wilson's disease: a practical guide from the British Association for the Study of the Liver. Lancet Gastroenterol Hepatol. 2022;7(6):560-575

5. Strathmann FG, Blum LM. Toxic elements. In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 7th ed. Elsevier; 2023:chap 44

6. Alman B, Fay M, Antezana A, et al. Toxicological Profile for Copper. ATSDR; 2022. Accessed January 22, 2024. Available atwww.atsdr.cdc.gov/toxprofiles/tp132.pdf

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

Total copper is analyzed by inductively coupled plasma mass spectrometry.(Unpublished Mayo method)

 

The labile bound copper fraction of serum is isolated from total copper through a series of filtration and chelation steps. Labile bound copper is then analyzed by inductively coupled plasma mass spectrometry.(Bitzer AC, Fox J, Day PL, et al. Establishment of a labile bound copper reference interval in a healthy population via an inductively coupled plasma mass spectrometry dual filtration-based assay. Arch Pathol Lab Med. 2023 Oct 23. doi:10.5858/arpa.2023-0259-OA)

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.

Wednesday

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.

7 to 14 days

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

14 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 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
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.

82525

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
LBCS Labile Bound Copper, S 105459-2
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.
620895 Labile Bound Copper, S 96257-1
620896 Labile Bound Copper Fraction 96463-5

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 | 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

Test Update Resources

Change Type Effective Date
New Test 2024-04-04