Test Catalog

Test Id : MUXF3

MUXF3 (Cross-reactive Carbohydrate Determinant), IgE, Serum

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

Evaluation for the presence of antibodies to cross-reactive carbohydrate determinates (CCD)


Investigation of clinically unexpected positive IgE antibody testing in a wide variety of plant and invertebrate allergens


The presence of IgE antibodies to cross-reactive carbohydrate determinants (CCD), such as bromelain derived MUX3, are associated with broad cross-reactivity with many plant and invertebrate allergens (including peanut allergens).


The presence of antibodies to CCD are generally not associated with allergenic symptoms but can cause confounding positive specific IgE antibody tests to a broad variety of allergens.

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

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

Fluorescence Enzyme Immunoassay (FEIA)

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


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


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




Specimen Type
Describes the specimen type validated for testing


Ordering Guidance

For a listing of allergens available for testing, see Allergens - Immunoglobulin E (IgE) Antibodies in Special Instructions

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


Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 0.5 mL for every 5 allergens requested

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

For 1 allergen: 0.3 mL

For more than 1 allergen: (0.05 mL x number of allergens) + 0.25 mL deadspace

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

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

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) 14 days
Frozen 90 days
Ambient 7 days

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

Evaluation for the presence of antibodies to cross-reactive carbohydrate determinates (CCD)


Investigation of clinically unexpected positive IgE antibody testing in a wide variety of plant and invertebrate allergens

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

Antibodies to glycoprotein carbohydrate determinants are prone to interact with a broad variety of plant and invertebrate allergens. These glycoprotein carbohydrates have therefore been termed cross-reactive carbohydrate determinants (CCD). The MUXF3 carbohydrate epitope obtained from digested pineapple bromelain glycoprotein can be used as a representative epitope marker for assessing the presence of IgE antibodies that interact with CCD. As true allergic sensitization to the pineapple bromelain glycoprotein itself is rare, assessing for the presence IgE antibodies reactive with the bromelain MUXF3 CCD glycoprotein carbohydrate epitope serves as a well-established marker for the determination of the presence of anti-CCD IgE antibodies.


CCD epitopes are widely distributed in plants and invertebrate animals, and antibodies against CCD, such as MUXF2, may be associated with a number of positive IgE antibody tests (cross-reactivity) to many different and unrelated plant allergens, but also to a number of potential invertebrate allergens such as bee/wasp venom, cockroaches, mites, and shellfish. Plant protein allergens that contain CCD epitopes include peanuts, grass, pollen, and latex. The presence of anti-CCD IgE antibodies can hinder assessment of the presence of IgE antibodies to these other plant and invertebrate allergens, as it is not possible to distinguish whether observed reactivity is due to the presence of antibodies specific to other proteins, or is the result of the presence of interfering anti-CCD antibodies. When very broad allergen sensitivity profiles are observed in the course allergy testing, it may be due to the presence of cross-reactive anti-CCD IgE antibodies, although the presence of IgE antibodies to profilin proteins should also be considered.


The degree to which antibodies to CCD may be associated with clinical allergic reaction has not been completely resolved. In general, the presence of cross-reactive antibodies to CCD, such as MUXF3, is not thought to be clinically relevant and does not give rise to symptoms consistent with allergic reaction. However, antibodies to CCD may be linked to clinically relevant allergic reactions in extremely rare cases, including in individuals with celery and tomato allergy.

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.


IgE kU/L



















Strongly positive



Strongly positive


> or =100

Strongly positive

Concentrations > or =0.70 kU/L (Class 2 and above) will flag as abnormally high.

Provides information to assist in interpretation of the test results

Antibody to bromelain MUXF3 has widely been used for assessing for potential cross-reactive carbohydrate determinate (CCD) cross-reactivity since its CCD chain is also found in many other plant proteins, including peanuts. While sensitization to CCD is generally not associated with an allergic reaction, the presence of IgE antibodies to CCD may give rise to confounding positive IgE antibody sensitization profiles for a wide variety of plant and invertebrate allergens.

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

Results from IgE antibody testing must be interpreted in the context of patient’s clinical evaluation and history of allergen exposures.


The presence of IgE antibodies to cross-reactive carbohydrate determinant (CCD) does not rule out the presence of antibodies specific to other antigens and clinically significant allergic reaction to other antigens.


Testing for IgE antibodies may not be useful in patients previously treated with immunotherapy to determine if residual clinical sensitivity exists, or in patients in whom the medical management does not depend upon identification of allergen specificity.


False-positive results for IgE antibodies may occur in patients with markedly elevated serum IgE (>2,500 kU/L) due to nonspecific binding to allergen solid phases.

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

1. Altmann F: Coping with cross-reactive carbohydrate determinants in allergy diagnosis. Allergo J Int. 2016;25(4):98-105. doi:10.1007/s40629-016-0115-3

2. Hemmer W, Altmann F, Holzweber F, Gruber C, Wantke F, Wohrl S: ImmunoCAP cellulose displays cross-reactive carbohydrate determinant (CCD) epitopes and can cause false-positive test results in patients with high anti-CCD IgE antibody levels. J Allergy Clin Immunol. 2018 Jan;141(1):372-381.e3. doi: 10.1016/j.jaci.2017.04.028

3. Sinson E, Ocampo C, Liao C, et al: Cross-reactive carbohydrate determinant interference in cellulose-based IgE allergy tests utilizing recombinant allergen components. PLoS One. 2020 Apr 23;15(4):e0231344. doi: 10.1371/journal.pone.0231344

4. van Ree R. Clinical importance of cross-reactivity in food allergy. Curr Opin Allergy Clin Immunol. 2004;4:235-40

5. Fotish K, Altmann F, Haustein D, Vieths S: Involvement of carbohydrate epitopes in the IgE response of celery-allergic patients. Int Arch Allergy Immunol. 1999 Sep;120:30-42. doi: 10.1159/000024217

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

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

Specific IgE from the patient's serum reacts with the allergen of interest, which is covalently coupled to an ImmunoCAP. After washing away nonspecific IgE, enzyme-labeled anti-IgE antibody is added to form a complex. After incubation, unbound anti IgE is washed away and the bound complex is then incubated with a developing agent. After stopping the reaction, the fluorescence of the eluate is measured. Fluorescence is proportional to the amount of specific IgE present in the patient's sample (ie, the higher the fluorescence value, the more IgE antibody is present).(Package insert: ImmunoCAP System Specific IgE FEIA. Rev 06/2019)

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


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 Friday

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.

Same day/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

14 days

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


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 Regional Manager. 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 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
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.


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
MUXF3 MUXF3 (CCD), IgE, S 58984-6
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.
MUXF3 MUXF3 (CCD), IgE, S 58984-6

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