Back to Search
Start Over
Reduction of cross-reactive carbohydrate determinants in plant foodstuff: elucidation of clinical relevance and implications for allergy diagnosis.
- Source :
-
PloS one [PLoS One] 2011 Mar 14; Vol. 6 (3), pp. e17800. Date of Electronic Publication: 2011 Mar 14. - Publication Year :
- 2011
-
Abstract
- Background: A longstanding debate in allergy is whether or not specific immunoglobulin-E antibodies (sIgE), recognizing cross-reactive carbohydrate determinants (CCD), are able to elicit clinical symptoms. In pollen and food allergy, ≥20% of patients display in-vitro CCD reactivity based on presence of α1,3-fucose and/or β1,2-xylose residues on N-glycans of plant (xylose/fucose) and insect (fucose) glycoproteins. Because the allergenicity of tomato glycoallergen Lyc e 2 was ascribed to N-glycan chains alone, this study aimed at evaluating clinical relevance of CCD-reduced foodstuff in patients with carbohydrate-specific IgE (CCD-sIgE).<br />Methodology/principal Findings: Tomato and/or potato plants with stable reduction of Lyc e 2 (tomato) or CCD formation in general were obtained via RNA interference, and gene-silencing was confirmed by immunoblot analyses. Two different CCD-positive patient groups were compared: one with tomato and/or potato food allergy and another with hymenoptera-venom allergy (the latter to distinguish between CCD- and peptide-specific reactions in the food-allergic group). Non-allergic and CCD-negative food-allergic patients served as controls for immunoblot, basophil activation, and ImmunoCAP analyses. Basophil activation tests (BAT) revealed that Lyc e 2 is no key player among other tomato (glyco)allergens. CCD-positive patients showed decreased (re)activity with CCD-reduced foodstuff, most obvious in the hymenoptera venom-allergic but less in the food-allergic group, suggesting that in-vivo reactivity is primarily based on peptide- and not CCD-sIgE. Peptide epitopes remained unaffected in CCD-reduced plants, because CCD-negative patient sera showed reactivity similar to wild-type. In-house-made ImmunoCAPs, applied to investigate feasibility in routine diagnosis, confirmed BAT results at the sIgE level.<br />Conclusions/significance: CCD-positive hymenoptera venom-allergic patients (control group) showed basophil activation despite no allergic symptoms towards tomato and potato. Therefore, this proof-of-principle study demonstrates feasibility of CCD-reduced foodstuff to minimize 'false-positive results' in routine serum tests. Despite confirming low clinical relevance of CCD antibodies, we identified one patient with ambiguous in-vitro results, indicating need for further component-resolved diagnosis.
- Subjects :
- Allergens immunology
Basophils immunology
Epitopes immunology
Food Hypersensitivity blood
Fruit chemistry
Gene Silencing
Humans
Immunoglobulin E blood
Immunoglobulin G blood
N-Acetylglucosaminyltransferases metabolism
Plant Extracts
Plant Proteins immunology
Reproducibility of Results
Carbohydrates immunology
Cross Reactions immunology
Food Hypersensitivity diagnosis
Food Hypersensitivity immunology
Solanum lycopersicum immunology
Solanum tuberosum immunology
Subjects
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 6
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 21423762
- Full Text :
- https://doi.org/10.1371/journal.pone.0017800