Basophil activation can predict clinical sensitivity in patients after venom immunotherapy.
OBJECTIVE
At present, no reliable in vitro test is available to monitor the success of specific venom immunotherapy (VIT) in preventing insect venom anaphylaxis. We investigated usefulness of the basophil activation test (BAT) in predicting the outcome of sting challenge in bee venom-allergic patients after VIT.


METHODS
Twenty-one patients with bee venom anaphylaxis at the end of VIT and 6 control participants were enrolled. BAT (flow-cytometric evaluation of allergen-induced expression of CD63), skin testing, and specific immunoglobulin (Ig) E determination were performed prior to sting challenge.


RESULTS
Five of the 21 patients (23.8%) reacted to sting challenge. At a bee venom concentration of 100 ng/mL, the mean proportion of basophils expressing CD63 was 56% in reactors and 13.2% in nonreactors (P = .0321). Four of the 5 reactors had positive results and 14 of the 16 nonreactors had negative results. Thus, using 18.4% and 21.6% (receiver operating characteristic curve analysis) as the cutoff for expression of the CD63 marker, the positive and the negative predictive values were 67% and 93%, respectively, and specificity and sensitivity for BAT were 80% and 83%, respectively. However, at a concentration of 1000 ng/mL, no significant differences in basophil activation were observed between reactors and nonreactors.


CONCLUSIONS
We found BAT to be a helpful tool in predicting the clinical sensitivity of bee venom-allergic patients after VIT (correlation between BAT at submaximal venom concentration and sting challenge).
Kucera
P
P
Department of Immunology, 3rd Faculty of Medicine, Charles University in Prague, Czech Republic. kucera@fnkv.cz
Cvackova
M
M
Hulikova
K
K
Juzova
O
O
Pachl
J
J
D000328:Adult; D000485:Allergens / Q000276:immunology / Q000627:therapeutic use; D000707:Anaphylaxis / Q000175:diagnosis / Q000276:immunology* / Q000628:therapy*; D015703:Antigens, CD / Q000276:immunology / Q000378:metabolism; D015549:Basophil Degranulation Test; D001491:Basophils / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D001514:Bee Venoms / Q000276:immunology / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D002469:Cell Separation; D003888:Desensitization, Immunologic; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D010980:Platelet Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity; D060149:Tetraspanin 30
D000485:Allergens; D015703:Antigens, CD; D001514:Bee Venoms; D015415:Biomarkers; C554586:CD63 protein, human; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30