Type-I allergies are being triggered by proteins, a class of bio-molecules constituting a critical building block of living cells, tissues and entire organs. Typically, at least several thousand proteins are contained in a particular biological source but only a few are capable of eliciting an allergic response in the immune system of a patient.

For example: In Europe the majority of birch pollen allergic patients (more than 95%) is sensitized against a single major allergen (Bet v 1) and a similar pattern has been observed in other environmental allergens such as grass pollens or cat hair.

Conventional allergy diagnosis, including skin and laboratory tests, employs crude allergen extracts for the determination of IgE antibodies. Frequently, these crude extracts are merely complex mixtures of bio-molecules produced by homogenization of the corresponding source material, possibly followed by a simple purification step. Consequently, these biological mixtures contain a large number of non-allergenic components. Typically, this leads to problems in the manufacturing of diagnostic assays, including the lack of standardization or the possible degradation of allergen molecules in the course of extract preparation.

Each manufacturer of allergy diagnostic tests (skin and laboratory) relies on different source materials and extraction procedures, therefore producing assays that differ in allergen composition and quality. For example, scientists have found that commercial extracts for skin testing may lack one or more of the major allergens contained in the particular biological source, possibly leading to false-positive test results. Also, allergen extracts can be contaminated with allergens from unrelated sources (e.g. animal dander contaminated with mites), possibly producing false-positive results in diagnostic assays.Eventually, an erroneous diagnosis may lead to the choice of a non-efficacious therapy or, even worse, generate side-effects resulting from the treatment!

Over the last 20 years, the disease-eliciting proteins in the most relevant allergy sources have been characterized on a molecular level. In sum, more than 1000 individual allergen molecules have described in detail. This development has been largely facilitated by the introduction of recombinant DNA technologies and improved high-throughput biocompatible purification methodologies and it has significantly boosted the creation of better diagnostic tests. For the first time, comprehensive panels of standardized allergen molecules can be used in novel diagnostic test formats, permitting the comprehensive profiling of disease-specific antibody patterns.

A major benefit of understanding the structural peculiarities of allergen molecules is their classification into families of structurally related and possibly cross-reactive proteins. Using purified allergen molecules instead of crude extracts for diagnostic testing paves the way for a paradigm shift in allergy diagnosis and treatment: Allergies can be classified on the basis of the reaction towards a particular class of allergen molecule.

Ultimately, many of these molecules will be used to develop novel therapies for allergic patients that improve the efficacy of the treatment while avoiding possible side-effects at the same time. Today, results of clinical studies indicate that these molecules lead to a better long-term reduction of symptoms, amongst others. The effective translation of allergen-molecule based immunotherapies into the clinical practice will benefit strongly from component-based tests as already today.
Unlike AllergySensor based on this innovative Biochip, conventional test systems don’t permit the analysis of several hundred individual disease-eliciting molecules in a single reaction. What’s more, the costs for determining a large number of disease-eliciting antibodies are significantly lower with  this test methode than when using state-of-the-art assays. Therefore, allergen-molecule based allergy tests  will change the way allergies are being diagnosed in the near future significantly. Please, get more information about AllergySensor on our website!