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Test Code PEANT Peanut, IgE with Reflex to Peanut Components, IgE, Serum

Reporting Name

Peanut Component Reflex, S

Useful For

Evaluation of patients with suspected peanut allergy


Evaluation of patients with possible peanut cross-reactivity

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type


Ordering Guidance

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

Specimen Required


Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 2 mL

Specimen Minimum Volume

0.75 mL

Testing Algorithm

Testing begins with analysis of peanut IgE. If peanut IgE is negative (<0.10 kU/L), testing is complete.


If peanut IgE is 0.10 kU/L or greater, then 7 peanut components (Ara h 2, Ara h 1, Ara h 3, Ara h 6, Ara h 8, Ara h 9, and profilin Bet v2) are performed at an additional charge.

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  90 days
  Ambient  7 days

Reference Values


IgE kU/L







Borderline / Equivocal












Strongly positive



Strongly positive



Strongly positive


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

Day(s) Performed

Monday through Friday

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


LOINC Code Information

Test ID Test Order Name Order LOINC Value
PEANT Peanut Component Reflex, S 6206-7


Result ID Test Result Name Result LOINC Value
PNUT Peanut, IgE, S 6206-7

Clinical Reference

1. Sicherer SH, Wood RA: Advances in diagnosing peanut allergy. J Allergy Clin Immunol Pract. 2013 Jan;1(1):1-13. doi: 10.1016/j.jaip.2012.10.004

2. Eller E, Bindslev-Jensen C: Clinical value of component-resolved diagnostics in peanut-allergic patients. Allergy. 2013 Feb;68(2):190-194. doi: 10.1111/all.12075

3. Hong X, Caruso D, Kumar R, et al: IgE, but not IgG4, antibodies to Ara h 2 distinguish peanut allergy from asymptomatic peanut sensitization. Allergy. 2012 Dec;67(12):1538-1546. doi: 10.1111/all.12047

4. Asarnoj A, Nilsson C, Lidholm J, et al: Peanut component Ara h 8 sensitization and tolerance to peanut. J Allergy Clin Immunol. 2012 Aug;130(2):468-472. doi: 10.1016/j.jaci.2012.05.019

5. Klemans RJ, van Os-Medendorp H, Blankestijn M, Bruijzeel-Koomen CA, Knol EF, Knulst AC: Diagnostic accuracy of specific IgE to components in diagnosing peanut allergy: a systematic review. Clin Exp Allergy. 2015 Apr;45(4):720-730. doi: 10.1111/cea.12412

6. Koid AE, Chapman MD, Hamilton RG, et al: Ara h 6 complements Ara h 2 as an important marker for IgE reactivity to peanut. J Agric Food Chem. 2014 Jan 8;62(1):206-213. doi:10.1021/jf4022509

7. Bublin M, Breiteneder H: Cross-reactivity of peanut allergens. Curr Allergy Asthma Rep. 2014 Apr;14(4):426. doi: 10.1007/s11882-014-0426-8

8. Chan ES, Greenhawt MJ, Fleischer DM, Caubet JC: Managing cross-reactivity in those with peanut allergy. J Allergy Clin Immunol Pract. 2019 Feb;7(2):381-386. doi: 10.1016/j.jaip.2018.11.012

9. Simberloff T, Parambi R, Bartnikas LM, el al: Implementation of a standardized clinical assessment and management plan (SCAMP) for food challenges. J Allergy Clin Immunol Pract. 2017 Mar-Apr;5(2):335-344. doi:10.1016/j.jaip.2016.05.021

Method Description

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. Phadia; Rev 06/2019)

Report Available

Same day/1 to 3 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Method Name

Fluorescent Enzyme Immunoassay (FEIA)

Secondary ID


Reflex Tests

Test ID Reporting Name Available Separately Always Performed
PNTCP Peanut Components, IgE, S No No