GA2LEN skin test study III: minimum battery of test inhalent allergens needed in epidemiological studies in patients

BACKGROUND

The number of allergens to be tested in order to identify sensitized patients is important in order to have the most cost-effective approach in epidemiological studies.

OBJECTIVE

To define the minimal number and the type of skin prick test (SPT) allergens required to identify a patient as sensitized using results of the new Pan-European GA(2)LEN skin prick test study.

METHOD

In a large Pan-European multicenter (17 centers in 14 countries) patient based study, a standardized panel of 18 allergens has been prick tested using a standardized procedure. Conditional approach allowed to determine the allergens selection.

RESULT

Among the 3034 patients involved, 1996 (68.2%) were sensitized to at least one allergen. Overall, eight allergens (grass pollen, Dermatophagoides pteronyssinus, birch pollen, cat dander, Artemisia, olive pollen, Blatella and Alternaria) allowed to identified more than 95% of sensitized subjects. However, differences were observed between countries, two allergens being sufficient for Switzerland (grass pollen and cat dander) as opposed to nine for France (grass pollen, Dermatophagoides pteronyssinus, olive pollen, cat dander, Blatella, cypress, dog dander, alder and [Artemisia or Alternaria]). According to country, up to 13 allergens were needed to identify all sensitized subjects.

CONCLUSION

Eight to ten allergens allowed the identification of the majority of sensitized subjects. For clinical care of individual patients, the whole battery of 18 allergens is needed to appropriately assess sensitization across Europe.

GA(2)LEN skin test study II: clinical relevance of inhalant allergen sensitizations in Europe

BACKGROUND

Skin prick testing is the standard for diagnosing IgE-mediated allergies. A positive skin prick reaction, however, does not always correlate with clinical symptoms. A large database from a Global Asthma and Allergy European Network (GA(2)LEN) study with data on clinical relevance was used to determine the clinical relevance of sensitizations against the 18 most frequent inhalant allergens in Europe. The study population consisted of patients referred to one of the 17 allergy centres in 14 European countries (n = 3034, median age = 33 years). The aim of the study was to assess the clinical relevance of positive skin prick test reactions against inhalant allergens considering the predominating type of symptoms in a pan-European population of patients presenting with suspected allergic disease.

METHODS

Clinical relevance of skin prick tests was recorded with regard to patient history and optional additional tests. A putative correlation between sensitization and allergic disease was assessed using logistic regression analysis.

RESULTS

While an overall rate of >or=60% clinically relevant sensitizations was observed in all countries, a differential distribution of clinically relevant sensitizations was demonstrated depending on type of allergen and country where the prick test was performed. Furthermore, a significant correlation between the presence of allergic disease and the number of sensitizations was demonstrated.

CONCLUSION

This study strongly emphasizes the importance of evaluating the clinical relevance of positive skin prick tests and calls for further studies, which may, ultimately, help increase the positive predictive value of allergy testing.

GA(2)LEN skin test study I: GA(2)LEN harmonization of skin prick testing: novel sensitization patterns for inhalant allergens in Europe

BACKGROUND

Skin prick testing is the standard for diagnosing IgE-mediated allergies. However, different allergen extracts and different testing procedures have been applied by European allergy centres. Thus, it has been difficult to compare results from different centres or studies across Europe. It was, therefore, crucial to standardize and harmonize procedures in allergy diagnosis and treatment within Europe.

AIMS

The Global Asthma and Allergy European Network (GA(2)LEN), with partners and collaborating centres across Europe, was in a unique position to take on this task. The current study is the first approach to implement a standardized procedure for skin prick testing in allergies against inhalant allergens with a standardized pan-European allergen panel.

METHODS

The study population consisted of patients who were referred to one of the 17 participating centres in 14 European countries (n = 3034, median age = 33 years). Skin prick testing and evaluation was performed with the same 18 allergens in a standardized procedure across all centres.

RESULTS

The study clearly shows that many allergens previously regarded as untypical for some regions in Europe have been underestimated. This could partly be related to changes in mobility of patients, vegetation or climate in Europe.

CONCLUSION

The results of this large pan-European study demonstrate for the first time sensitization patterns for different inhalant allergens in patients across Europe. The standardized skin prick test with the standardized allergen battery should be recommended for clinical use and research. Further EU-wide monitoring of sensitization patterns is urgently needed.