The Science Behind ImmunoCAP® Molecular Allergy


ImmunoCAP Molecular Allergy provides two new assays to help specialist clinicians and researchers target their diagnosis of allergic disease: ImmunoCAP® Allergen Components, a new menu of highly refined allergen component tests, and ImmunoCAP ISAC® (Immuno Solid-phase Allergen Chip), an initial allergy clinical assessment for the 21st century. Both of these are laboratory-developed tests available to specialists only through PiRL.


Taking the molecular view of allergens

ImmunoCAP Allergen Components enable the measurement of specific antibodies to antigenic components at the molecular level. The measurement of very specific antibodies to these molecular components allows a level of specificity in detection never before seen. While the clinical utility of these component results is just now being understood, it is an exciting time as we advance the understanding of immunology.


Currently available ImmunoCAP specific IgE (sIgE) testing provides precise, accurate, and valuable information about a patient’s sensitization to 1 or more allergens. The level of sIgE to any given allergen is an important consideration when evaluating a patient’s allergic status, because the probability of symptoms increases with increasing amounts of sIgE.1-3 However, the clinical manifestation of some allergies is dependent upon additional contributing factors. This is true in the case of wheat-dependent, exercise-induced anaphylaxis, for example.


ImmunoCAP Allergen Components

ImmunoCAP Allergen Components, highly refined specific allergy testing, employs carefully selected components and recombinant engineered allergens. Using ImmunoCAP Allergen Components can help refine your understanding of sensitization by assessing a person’s sensitization pattern at the molecular level.4,5 Test results from allergen components demonstrate, for instance, that similar protein structures from widely divergent allergenic sources can generate clinically relevant cross-reactions. When used in conjunction with traditional extract-based sIgE testing, ImmunoCAP Allergen Components provide information at the individual component level.

ImmunoCAP ISAC®: Immuno Solid-phase Allergen Chip

The most advanced diagnostic technology—and one of the most exciting—is ImmunoCAP ISAC, a multiarray technology package designed for the assessment of patients in the initial allergist office workup. Using just a small blood sample, ISAC produces semi-quantitative results—both recombinant and highly purified—representing a wide spectrum of allergens. This profile will produce unique patterns for every patient.


ImmunoCAP ISAC offers:

  • Specific IgE measurement of allergen components from nearly 50 different allergen sources
  • Semi-quantitative results for 112 allergen components
  • Component resolved diagnostics using only purified natural or recombinant allergen components

Recombinant Allergen Technology

The molecular-level component antigens have been characterized and prepared in a recombinant system or highly purified from a native source. Traditional sIgE testing utilizes allergens that are composed of complex mixtures of allergen components derived from a single allergen source. In contrast, ImmunoCAP Molecular Allergy testing utilizes—in place of complex extract-based mixtures—purified recombinant and native protein molecules.


A recombinant allergen is a biotechnologically produced allergen molecule with a peptide sequence identical to those originally isolated from an allergen extract. The native purified components are used where it is possible to isolate the protein by traditional chemical and immunochemical methods. Recombinant and native allergen components are thus comparable with their natural proteins in structural and immunological properties, and have IgE antibody-binding capacity similar to that of the natural allergen in vitro and in vivo.



1. Sampson HA, Ho DG. J Allergy Clin Immunol. 1997;100:444-451.

2. Sampson HA. J Allergy Clin Immunol. 2001;107:891-896.

3. Simpson A, et al. J Allergy Clin Immunol. 2005;116:744-749.

4. Valenta R, et al. Clin Exp Allergy. 1999;29:896-904.

5. Heiss S, et al. J Invest Dermatol. 1999;113:830-837.