IgE to Cross-Reactive Carbohydrate Determinants: Analysis of the Distribution and Appraisal of the in vivo and in vitro ReactivityMari A.
Allergy Unit, National Health Service, Rome, Italy
Background: IgE to cross-reacting carbohydrate determinants has already been described by several authors, but their function and distribution are still a matter of debate. In previous studies we showed how the presence of IgE to bromelain could be a useful and simple marker of the presence of IgE to carbohydrate epitopes. Methods: A survey of 1,831 subjects with a suspected allergic respiratory disease has been carried out by detecting IgE to bromelain. Data were analysed on the basis of demographical and allergological parameters. To find out whether a glycoprotein is capable of triggering an allergic reaction, 1,076 subjects were also skin tested with several purified molecules bearing carbohydrate side chains differing in number, composition and complexity. Results: An overall prevalence of 23% of positive IgE to cross-reacting carbohydrate determinants was recorded. Prevalence varied when subsets of non-allergic (5%), non-pollen-allergic (10%), and pollen-allergic (31%) subjects were considered. Prevalence further increased in subsets with multiple pollen sensitization (71%), and with a previous pollen immunotherapy course (46%), whereas minor differences were found in gender and age distribution. Almost all the allergenic extracts recorded negative in the skin test gave a positive IgE test in vitro. A higher correlation was found mainly with plant-derived allergenic extracts, whereas a lower one was recorded with mites and fungi. Horseradish peroxidase was the only glycoprotein capable of exerting a positive skin test in 21% of the subjects with IgE to cross-reacting carbohydrate determinants, 80% of them having IgE to the HRP molecule. Conclusions: IgE to cross-reacting carbohydrate determinants are common among the allergic population and the binding to skin test negative allergenic extracts further confirms their poor biological activity. Further studies on horseradish peroxidase should be carried out to define the role of the glycan side chains in its allergenic activity.
Correspondence to: Dr. Adriano Mari
Via Malipiero 28
I–04100 Latina (Italy)
Tel. +39 330 860005, Fax +39 0773 620787
Received: Received: May 15, 2002
Accepted after revision: August 13, 2002
Number of Figures : 6, Number of Tables : 1, Number of References : 30
International Archives of Allergy and Immunology
Vol. 129, No. 4, Year 2002 (Cover Date: December 2002)
Journal Editor: D. Kraft, Vienna
ISSN: 1018–2438 (print), 1423–0097 (Online)
For additional information:http://www.karger.com/journals/iaa