Minor Interference of Cross-Reactive Carbohydrates with the Diagnosis of Respiratory Allergy in Standard Clinical Conditions

Abstract

Background: Immunoglobulin E (IgE) to N-glycans from plant and invertebrate glycoproteins induces extensive in vitro cross-reactivity. This study investigates the prevalence and diagnostic relevance of IgE to these N-glycans [cross-reactive carbohydrate determinants (CCDs)] in patients with suspicion of respiratory allergy. Methods: A total of 1,025 adult subjects with symptoms of rhinitis and/or asthma from a reference allergy clinic were studied. Determinations included a structured questionnaire, skin prick tests (SPT), total IgE, a multiallergen IgE test and specific IgE (sIgE) to bromelain, MUXF (the bromelain-type N-glycan) and honeybee phospholipase-A2. Inhibition studies with CCDs were performed in selected cases. Results: The prevalence of CCD sensitization (MUXF sIgE and/or bromelain-sIgE ≧0.1 kU_A/l) was 18.0%. Male sex and atopy (SPT positivity) were associated with CCD sensitization. Sensitization was more frequent in patients sensitized to pollens than in those sensitized to mites, the most common inhalant allergens in the area. A history of Hymenoptera stings was associated with CCD sensitization and multiallergen IgE test positivity. CCD sensitization was not significantly associated with age, rural residence, alcohol consumption or smoking. Only 58 patients (5.6%) showed CCD-sIgE levels ≧0.35 kU_A/l. CCD-induced inhibition of pollen-sIgE or mite-sIgE in patients with respective positive SPT was minimal or absent in most cases. Conclusions: In this population of predominantly mite-allergic patients, CCD sensitization is relatively rare and CCD-sIgE levels are low. Thus, CCDs do not represent a major obstacle for the diagnosis of respiratory allergy in a specialized setting. Hymenoptera stings are associated with CCD sensitization.

A Comprehensive Analysis of Middle-European Molecular Sensitization Profiles to Pollen Allergens

“…The sensitization rate to the CCD component MUXF3 in pollen-sensitized patients was 6.5%, and this rate was similar to the result of another recent study [8]. Patients showing positivity to natural purified components were more frequently sensitized to MUXF3 than was the group as a whole - e.g.…”

Prevalence of cross‐reactive carbohydrate determinants in UK bakers

“…A similar prevalence of CCD‐specific IgE (6%) was found in a large Spanish study of adults attending a respiratory allergy clinic with a higher prevalence in those sensitised to pollens rather than house dust mite . Our study's prevalence of CCD‐specific IgE was lower than that reported by Sander et al .…”

“…These carbohydrate determinants are immunologically similar and highly cross-reactive and can interfere with IgE-specific assays, such as wood dust [3], which may result in a misdiagnosis of occupational allergy. The prevalence of specific IgE to cross-reactive carbohydrate determinants (CCDs) in occupational respiratory allergy is not well described; however, it has been reported to be 6% in Spanish adults attending a respiratory allergy clinic [4], 10% in Polish workers with suspected occupational respiratory allergy [5] and 25% in German bakers [6].In the study of German bakers, the majority of bakers had cosensitisation to both wheat flour and grass pollen, which raises the possibility that CCDs may be responsible for the cross-reactivity between grass and wheat flour [6], although previous studies have suggested that there is little cross-reactivity between these allergens [7]. In the Spanish bakers, CCDs have been reported to be at least partly responsible for the crossreactivity observed between wheat flour and kiwi fruit [8].The aim of our study was to determine the prevalence of specific IgE to CCD in UK bakers and determine whether CCDs interfere with the accuracy of wheat flour-specific IgE assays, particularly in those bakers cosensitised to grass pollen.Serum samples were obtained from bakers (n = 209) who were attending the occupational lung disease clinic at the Royal Brompton and Harefield NHS Trust, London, for investigations into possible diagnosis of occupational asthma.…”

Identification of cross-reactive carbohydrate determinants in subjects reporting work-related respiratory symptoms

“…Also Kespohl et al did not find correlation between positive results of sIgE to the most common inhalative allergens and CCDs [22]. Other results demonstrated that in CCDpositive patients with suspected respiratory allergy, male sex and atopy were associated with CCD sensitization and this sensitization was more frequent in pollen-sensitized patients than in those sensitized to mites [24]. In Vidal et al study, CCD sensitization was not significantly associated with age, rural residence, alcohol consumption or smoking [24].…”

“…Other results demonstrated that in CCDpositive patients with suspected respiratory allergy, male sex and atopy were associated with CCD sensitization and this sensitization was more frequent in pollen-sensitized patients than in those sensitized to mites [24]. In Vidal et al study, CCD sensitization was not significantly associated with age, rural residence, alcohol consumption or smoking [24]. On the other hand, among beekeepers, the presence of anti-CCD IgE was positively associated with atopy and higher levels of serum total IgE [23].…”