Cross-reactive carbohydrate determinants strongly affect the results of the basophil activation test in hymenoptera-venom allergy.
BACKGROUND
In hymenoptera-venom allergy, sera of up to 60% of patients show in vitro reactivity to honeybee venom (HBV) and yellow jacket venom (YJV). This phenomenon is mainly caused by specific IgE (sIgE) against cross-reactive carbohydrate determinants (CCD). Whether or not these antibodies can induce clinical symptoms is a longstanding debate.


OBJECTIVE
The aim of this study was to investigate the biological activity of CCD-sIgE and the suitability of the basophil activation test (BAT) in hymenoptera venom-allergic patients having CCD-sIgE.


METHODS
The biological activity of CCD-sIgE was analysed by application of native and CCD-depleted YJV and HBV in BAT with the blood of 62 hymenoptera venom-allergic patients and 16 non-allergic controls. According to results of intracutaneous skin tests (IC) with YJV and HBV and the existence of CCD-sIgE, patients were classified into six subgroups.


RESULTS
In patients with mono-positive IC and CCD-sIgE, and thus double-positive sIgE, BAT with native venoms was also double positive in up to 67% of the patients. In contrast, BAT with CCD-depleted venoms was positive only with the IC-positive venom. However, activation of basophils with the IC-negative venom was significantly lower compared with the IC-positive one. In IC mono-positive patients without CCD-sIgE, BAT was mono-positive with the IC-positive venom in the native and in the CCD-depleted form. CCD-positive patients with double-positive IC were a heterogeneous group, with the majority of CCD-positive patients also being double positive with the native forms of both venoms but mono-positive with the CCD-depleted ones.


CONCLUSIONS
In vitro BAT clearly demonstrates biological activity of CCD-sIgE. However, because most of the patients showed a mono-positive IC and activation of basophils with the IC-negative venom was significantly lower compared with the IC-positive one, the present data suggest that CCD-sIgE is clinically irrelevant in these patients.
Mertens
M
M
Department of Dermatology, University of Münster, Von-Esmarch-Strasse 58, Münster, Germany. melanie.mertens@ukmuenster.de
Amler
S
S
Moerschbacher
B M
BM
Brehler
R
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology*; D000918:Antibody Specificity; D001491:Basophils / Q000276:immunology*; D001514:Bee Venoms / Q000276:immunology*; D002241:Carbohydrates / Q000276:immunology*; D003429:Cross Reactions; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis*; D007073:Immunoglobulin E / Q000276:immunology; D007159:Immunologic Tests / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014862:Wasp Venoms / Q000276:immunology*
D000485:Allergens; D001514:Bee Venoms; D002241:Carbohydrates; D014862:Wasp Venoms; D007073:Immunoglobulin E