In vitro allergy testing needs better standardization--test results from different laboratories lack comparability mostly due to missing effective standards.

Correct determination of specific IgE is important for the diagnosis of allergic diseases. Different detection systems are supposed to yield similar results of this standardized parameter. In order to investigate this assumption, 40 sera from allergic patients were sent in eight mailings to 23 laboratories over a 2-year period. Three IgE determinations in each serum had to be performed according to laboratory-specific methods. Whereas 'wrong' results were rare with any of the methods and the overall results to a large degree comparable, sensitivity and specificity seemed to vary considerably between antigens, methods, companies and laboratories. According to our observations, better standardization of test reagents and test methods by the suppliers is essential in order to harmonize the test results and to avoid wrong conclusions. At present, the diversity of techniques that are used for IgE determination leads to quite divergent results, and the allergist has to know that. And finally, the legislator is urged to better control these diagnostic tools, because wrong results may lead to life-threatening situations.