Reference values of IgG and IgG₄ serum levels specific for inhalant allergens in non-atopic children

Background: An IgG response to allergens has been well characterized, however few studies have investigated IgG and IgG4 production in normal subjects. Objective: The aim of this study was to find reference values for six common inhalant allergens in a population of healthy children. Methods: One hundred and six females and 107 males, from one to 12 years old, were studied assessing the serum levels of specific total IgG and IgG4 for six allergens. Results: A homogeneous behaviour was not observed, among allergens or among patient subgroups. Some allergens increased, while others decreased from pre-school to elementary school age. In females, this decrease was less evident, while increases were more evident. Differences were found between seasonal and perennial allergens, the latter showing higher values. We also observed differences between temporal trends of IgG and IgG₄ in some patient groups. Percentiles of distributions have been provided as reference values, for all subgroups that were significantly different. Conclusion: Defining an individual profile would be useful for characterising the specific humoral response.