Test Includes
Horse IgE; Reflex criteria: If Horse IgE ≥0.35 kU/L, Equ c IgE will be performed.
Expected Turnaround Time
2 - 4 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Documents
Specimen Requirements
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL (Note: This volume does not allow for repeat testing.)
Container
Gel-barrier tube
Storage Instructions
Room temperature
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 3 months |
Freeze/thaw cycles | Stable x3 |
Test Details
Use
The diagnostic assessment of allergy starts with the patient’s clinical history and examination and is followed by an extract-based analysis to confirm the presence of specific IgE (sIgE) antibody.1 sIgE is necessary but not sufficient for eliciting an allergic response and thus generating a definitive diagnosis of allergic disease. Testing utilizing allergenic extracts does not lend itself to the differentiation of primary sensitization from a cross-reactivity-driven response because of the complexity of the extracts. Extracts contain most of the extractable allergenic components from the suspected sensitizer. However it is often not possible to predict the relative risk of having a systemic allergic reaction using an extract-based diagnostic test. Component Resolved Diagnostics (CRD) refers to the use of purified or recombinant allergens in the serologic assessment of individuals who suffer reproducible hypersensitivity reactions with exposures to an allergen at a dose tolerated by non-allergic individuals.1,2 This approach offers advantages over the use of a complete extract, especially in polysensitized individuals, given its usefulness for distinguishing between sensitizations specific to singular species and sensitizations due to cross-reactivity.3
Limitations
Allergen-specific IgE assays do not demonstrate absolute positive and negative predictive values for allergic disease. Clinical history must be incorporated into the diagnostic determination. Although the use of component resolved IgE testing may enhance the evaluation of potentially allergic individuals over the use of whole extracts alone, it cannot yet replace clinical history and oral food challenge in most cases. Sensitization against thus far unidentified determinants that are not found in the whole extract or in components might cause symptoms in rare cases.
Methodology
Thermo Fisher ImmunoCAP® Allergen-specific IgE
Additional Information
Equ c 1
The horse allergen, Equ c 1, was one of the first major allergens to be isolated, cloned and characterized4-6 and up to 76% of patients with horse allergy react to Equ c 1.7-9 Equ c 1 is generally accepted as the major horse allergen, although the sensitization profile among horse sensitized individuals has not been comprehensively characterized.10 There is a close structural relationship between Equ c 1 and a number of proteins from other species including cat (Fel d 4), dog (Can f 6), rabbit (Ory c 4), rat (Rat n 1) and mouse (Mus m 1).7,11-13 Equ c 1 and homologous allergens is thought to contribute to multi-sensitization and symptoms in individuals allergic to mammals. Allergic sensitization to multiple animals without exposure to specific species may put patients at risk for unexpected respiratory symptoms may develop after an occasional animal contact.14 Asthmatic children sensitized to Equ c 1 have been shown to be at a greater risk of having more severe symptoms.15-17
Footnotes
1. Matricardi PM, Kleine-Tebbe J, Hoffmann HJ, et al. EAACI Molecular Allergology User’s Guide. Pediatr Allergy Immunol. 2016 May;27 Suppl 23:1-250.27288833
2. Eiringhaus K, Renz H, Matricardi P, Skevaki C. Component-Resolved Diagnosis in Allergic Rhinitis and Asthma. J Applied Lab Med. 2019 Feb;3(5):883-898.10.1373/jalm.2018.026526
3. Liccardi G, Bilo MB, Manzi F, Piccolo A, Di Maro E, Salzillo A. What could be the role of molecular-based allergy diagnostics in detecting the risk of developing allergic sensitization to furry animals? Eur Ann Allergy Clin Immunol. 2015 Sep;47(5):163-167.26357003
4. Goubran Botros H, Poncet P, Rabillon J, Fontaine T, Laval JM, David B. Biochemical characterization and surfactant properties of horse allergens. Eur J Biochem. 2001 May;268(10):3126-3136.11358533
5. Gregoire C, Rosinski-Chupin I, Rabillon J, Alzari PM, David B, Dandeu JP. cDNA cloning and sequencing reveal the major horse allergen Equ c1 to be a glycoprotein member of the lipocalin superfamily. J Biol Chem. 1996 Dec 20;271(51):32951-32959.8955138
6. Liccardi G, Emenius G, Merritt AS, Salzillo A, D’Amato M, D’Amato G. Direct and indirect exposure to horse: risk for sensitization and asthma. Curr Allergy Asthma Rep. 2012 Oct;12(5):429-347.22717671
7. Saarelainen S, Rytkönen-Nissinen M, Rouvinen J, et al. Animal-derived lipocalin allergens exhibit immunoglobulin E cross-reactivity. Clin Exp Allergy. 2008 Feb;38(2):374-381.18070162
8. Bjerg A, Winberg A, Berthold M, Mattsson L, Borres MP, Rönmark E. A population-based study of animal component sensitization, asthma, and rhinitis in schoolchildren. Pediatr Allergy Immunol. 2015 Sep;26(6):557-563.26059105
9. Konradsen JR, Nordlund B, Onell A, Borres MP, Grönlund H, Hedlin G. Severe childhood asthma and allergy to furry animals: refined assessment using molecular-based allergy diagnostics. Pediatr Allergy Immunol. 2014 Mar;25(2):187-192.24460778
10. Nilsson OB, van Hage M, Gronlund H. Mammalian-derived respiratory allergens - implications for diagnosis and therapy of individuals allergic to furry animals. Methods. 2014 Mar 1;66(1):86-95.24041755
11. Jakob T, Hilger C, Hentges F. Clinical relevance of sensitization to cross-reactive lipocalin Can f 6. Allergy. 2013;68(5):690-691.23464491
12. Nilsson OB, Binnmyr J, Zoltowska A, Saarne T, van Hage M, Grönlund H. Characterization of the dog lipocalin allergen Can f 6: the role in cross-reactivity with cat and horse. Allergy. 2012 Jun;67(6):751-757.22515174
13. Hilger C, Swiontek K, Arumugam K, Lehners C, Hentges F. Identification of a new major dog allergen highly cross-reactive with Fel d 4 in a population of cat- and dog-sensitized patients. J Allergy Clin Immunol. 2012 Apr;129(4):1149-1151.22104604
14. Liccardi G, Passalacqua G, Salzillo A, et al. Is sensitization to furry animals an independent allergic phenotype in nonoccupationally exposed individuals? J Investig Allergol Clin Immunol. 2011;21(2):137-141.21462804
15. Nordlund B, Konradsen JR, Kull I, et al. IgE antibodies to animal-derived lipocalin, kallikrein and secretoglobin are markers of bronchial inflammation in severe childhood asthma. Allergy. 2012 May;67(5):661-669.22339365
16. Hentges F, Leonard C, Arumugam K, Hilger C. Immune responses to inhalant Mammalian allergens. Front Immunol. 2014 May 21;5:234.24904583
17. Nwaru BI, Suzuki S, Ekerljung L, et al. Furry Animal Allergen Component Sensitization and Clinical Outcomes in Adult Asthma and Rhinitis. J Allergy Clin Immunol Pract. 2019 Apr;7(4):1230-1238.e4.30594587
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 606656 | IgE Horse w/ Component Reflex | 7419-5 | 602444 | Class Description | N/A | |
| 606656 | IgE Horse w/ Component Reflex | 7419-5 | 606843 | E003-IgE Horse Dander | kU/L | 7419-5 |
| Reflex Table for E003-IgE Horse Dander | ||||||
|---|---|---|---|---|---|---|
| Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
| Reflex 1 | 606577 | Panel 606577 | 606658 | E227-IgE Equ c 1 | kU/L | Pending |
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