Basophil response and the induction of a tolerance in venom immunotherapy: a long-term sting challenge study.
ABSTRACT There is no in vitro test to predict the induction of long-term tolerance in patients treated with venom immunotherapy (VIT). The aim of this study was to investigate whether immunotherapy-induced changes in basophil responsiveness reflect a state of protection and the induction of a tolerance.
Twenty-three patients with allergic reaction after Hymenoptera sting (11 wasp and 12 honeybee) were treated with VIT. In all patients, a CD63 basophil activation test was performed before the beginning of immunotherapy, after 1 year and after completing 4-6.5 years of immunotherapy (approximately 1 year after stopping). The tolerance was then evaluated by a sting challenge test. The basophil activation test was repeated 3-6 months after the challenge.
Twenty-two subjects showed a negative sting challenge, and one subject, a positive sting challenge. Allergen-specific basophil response remained unchanged after 1 year of immunotherapy. However, after immunotherapy, a significant and approximately fourfold decrease was demonstrated in all tolerant subjects mainly in response to submaximal 0.1 μg/ml allergen concentration. This depression was sustained and did not change with the sting challenge test. In a nontolerant patient with a positive sting challenge, basophil response did not change.
Our results suggest that the depression of allergen-specific basophil response seems to be associated with the induction of a tolerance after completing a course of VIT.
- Allergy 05/1996; 51(4):216-25. · 5.88 Impact Factor
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ABSTRACT: Whole-body extracts of Hymenoptera were used for diagnosis and treatment until controlled clinical trials proved them no better than placebo, whereas venom is 85% to 98% effective. Studies of natural history reveal why whole-body extracts were thought to work. The chance of future systemic reactions is low in large local reactors and in most children and varies between 20% and 70% in adults. Venom skin tests are most accurate, but RAST is an important complementary test. The degree of sensitivity on skin tests or RASTs does not reliably predict the severity of a sting reaction. Venom immunotherapy is recommended for patients at high risk for sting reactions. Rapid regimens are as safe as slower regimens. The recommended dose is 100 microg, but some patients require higher doses for full protection. Venom immunotherapy is continued every 4 to 8 weeks for at least 5 years in most cases. Skin test results become negative in only 25% after 5 years of therapy but in 60% to 70% after 7 to 10 years. When treatment is stopped after 5 years or more, there is a 10% chance of systemic reaction to each future sting, but most reactions are mild. Some patients have a higher risk of relapse and should continue treatment for an extended period.Journal of Allergy and Clinical Immunology 04/2005; 115(3):439-47; quiz 448. · 12.05 Impact Factor
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ABSTRACT: Venom allergen immunotherapy (VIT) is proven to be highly effective for insect allergy, but the mechanisms and the biomarkers associated with clinical efficacy remain elusive. The aim of this study was to identify candidate biomarkers associated with successful VIT. Gene chip array and clustering analyses of PBMCs from subjects with or without VIT were performed. From gene chip array and clustering analyses, an increased expression of osteopontin was found in patients who completed 5 to 6 years of VIT and discontinued therapy for 3 to 6 years (completed treatment group) compared with the untreated group. A significantly higher level of serum osteopontin was found in the completed treatment group compared with the untreated group (n = 16 in each group; P < .001). The upregulation of osteopontin after VIT suggests a role of osteopontin as a candidate biomarker for VIT.Journal of Allergy and Clinical Immunology 05/2005; 115(5):1063-7. · 12.05 Impact Factor