BACKGROUND: The mechanisms responsible for the difference between clinically irrelevant IgE-sensitization and allergic rhinitis are not fully understood. OBJECTIVE: We evaluated the humoral and cellular mechanisms that may be associated with the presence of allergic rhinitis symptoms. METHODS: We selected 26 subjects with positive grass pollen skin tests and IgE antibodies to Timothy (g6) and the major grass allergens rPhl p 1, 5b. Fourteen of those patients reported a history of allergic rhinitis. During winter, we performed a grass pollen CD63 basophile activation test using four log allergen concentrations, followed by a grass nasal provocation test (NPT). We obtained symptom scores in the subsequent pollination season. RESULTS: We showed that subjects with a positive NPT have significantly higher CD63 basophile grass pollen responsiveness than NPT-negative subjects, preferably at submaximal allergen concentrations, which represent cellular sensitivity. Moreover, basophile sensitivity positively correlated with the size of the grass-specific IgE fraction in relation to total IgE, and it was highly predictive of allergic rhinitis symptoms in the following pollination season. CONCLUSION AND CLINICAL RELEVANCE: Allergic rhinitis symptoms are significantly associated with allergen-specific basophile sensitivity. In vitro evaluation of basophile sensitivity should prove useful for distinguishing clinical phenotype of allergic sensitization.
COBISS.SI-ID: 28743129
Our results suggest that the current CAP-FEIA rApi m 1 has limited clinical usefulness for the detection of honeybee venom allergy, due to its low diagnostic sensitivity. Thus, improved diagnostic tests are needed.
COBISS.SI-ID: 28926425
Background: New in vitro methods are essential for developing better follow-up criteria for venom immunotherapy (VIT). Methods: Thirty-one children with a history of honeybee venom–induced systemic anaphylaxis were included in this prospective, single-blinded study. The basophil CD63 activation test (BAT) was assessed before starting VIT, at the end of the build-up phase (day five), 6 months later, and after 2 to 4 years of VIT. Results: BAT allowed identification of the culprit insect in 74% of honeybee venom–allergic children. In comparison, IgE reactivity was single positive in only 52% of children. Five days after starting VIT, BAT was highly comparable to before VIT. However, after 6 months and further after 2 to 4 years of VIT, a significant and approximately fourfold decrease was demonstrated in CD63 response at sub-maximal 0.1 µg/ml allergen concentration, which mainly represents cellular sensitivity. No such differences were found at a higher 1 µg/ml of allergen concentration. Person-to-person analyses showed that after 2 to 4 years of VIT a marked CD63 decrease was evident in 85% of children. In addition, elevated basophil sensitivity measured before VIT was associated with the appearance of side effects observed during the build-up phase of VIT. Conclusion: Basophil CD63 allergen–specific sensitivity seems to be a promising tool for monitoring protective immune response in honeybee VIT.
COBISS.SI-ID: 29193177