Home About us Contact
|
Home About us Contact | ||
|
|
||
Venom Anaphylaxis (venom + anaphylaxis)
Selected AbstractsComparison of basophil activation tests using CD63 or CD203c expression in patients with insect venom allergyALLERGY, Issue 9 2006B. Eberlein-König Background:, Flow cytometric basophil activation tests have been developed as cellular tests for in vitro diagnosis of IgE-mediated reactions. Different activation markers (CD63 or CD203c) with distinct ways of regulation have been used after stimulation with various allergens. Objective:, It was the aim of the present study to compare basophil activation tests by measuring both CD63 and CD203c upregulation in patients with insect venom allergy. Materials and methods:, 43 patients with a history of insect venom anaphylaxis were examined. A careful allergy history was taken, and skin tests and determination of specific IgE-antibodies were performed. Basophil activation tests (BAT) using CD63 or CD203c expression were done after stimulation with different concentrations of bee and wasp venom extracts. 25 healthy subjects with negative history of insect venom allergy were studied as controls. Results:, The CD203c protocol showed a slightly higher sensitivity than the CD63 protocol (97% vs. 89%) with regard to patients' history. The magnitude of basophil response was higher with CD203c in comparison to CD63 for both insect venoms. Specificity was 100% for the CD63 protocol and 89% for the CD203c protocol with regard to controls with negative history and negative RAST. Conclusion:, These results support the reliability of basophil activation tests using either CD63 or CD203c as cellular tests in the in vitro diagnosis of patients with bee or wasp venom allergy with a slightly higher sensitivity for the CD203c protocol. [source] Sensitization to cross-reactive carbohydrate determinants and the ubiquitous protein profilin: mimickers of allergyCLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2004D. G. Ebo Summary Background During the last decade, evidence has been provided for profilins and cross-reactive carbohydrate determinants (CCDs) to be capable of inducing cross-reactive IgE antibodies with little clinical relevance. Objective To investigate the prevalence of sensitization to CCD and profilin in isolated allergies (birch, timothy grass, house dust mite, pets (cat and/or dog), natural rubber latex (NRL) and hymenoptera venom). To study the contribution of anti-CCD and anti-profilin IgE antibodies as a cause of clinically irrelevant IgE for NRL and apple. Methods For the first part of the study, 100 patients with inhalant allergy, 17 patients with NRL allergy and 40 patients with venom anaphylaxis were enrolled. Diagnosis was based on a questionnaire and a positive IgE determination and skin test for relevant allergen. Patients were identified as sensitized to CCD if they had a negative prick test and positive IgE for the glycoprotein bromelain. Sensitization to profilin was assessed by IgE for rBet v 2 (recombinant birch profilin). For the second part of the study, sera containing IgE against apple (n=82) or NRL (n=38) were classified as true-negative or false-positive according to the presence or absence of an oral allergy syndrome (OAS) or NRL-induced anaphylaxis. In these patients, sensitization to CCD and profilin was evaluated as described above. Results No sensitization to bromelain-type CCD and profilin was found in isolated birch pollen or NRL allergy. In contrast, sensitization to bromelain-type CCD was found in 4/17 patients with isolated grass pollinosis, 5/24 patients with combined pollinosis (birch, timothy, mugwort) and 7/33 patients with venom anaphylaxis. Sensitization to profilin was almost restricted to patients with combined pollen allergy (5/24). In pollen-allergic individuals with a false-positive IgE against NRL the prevalence of sensitization to bromelain-type CCD and profilin IgE was higher than in NRL-allergic patients (P<0.00001 and P=0.0006, respectively). In pollen-allergic individuals with a false-positive IgE to apple, the frequency of sensitization to bromelain-type CCD was higher than in OAS patients (P=0.004). Clinically irrelevant NRL and apple were also found in four and five out of the seven patients sensitized to venom CCD, respectively. In pollinosis, clinically irrelevant NRL and apple IgE antibodies were inhibited by bromelain and recombinant birch profilin, whereas in isolated venom anaphylaxis these antibodies were inhibited by bromelain. Conclusions Patients monoallergic to NRL or birch pollen showed no sensitization to bromelain-type CCD or profilin. Sensitization to profilin and/or bromelain-type CCD, caused by pollen (timothy grass, mugwort) or hymenoptera venom allergens, can elicit false-positive IgE antibodies against NRL and apple. [source] Systemic reactions to immunotherapy: influence of composition and manufacturerCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2003G. Gastaminza Summary Background Although immunotherapy clearly demonstrated the benefit of reducing allergic symptoms, it has the drawback of adverse events, mainly systemic reactions that could be very inconvenient for patients and even life-threatening. Objective The aim of the present study was to assess the incidence of systemic reactions to immunotherapy in a large number of patients, and its potential relationship with the characteristics of therapy, such as allergen composition or manufacturing laboratory. Methods This study analysed the administration of specific immunotherapy during a period of 5 years, involving 1212 patients affected by respiratory hypersensitivity or hymenoptera venom anaphylaxis. Commercial extracts were supplied by five different laboratories. All the patients were attended at an out-clinic immunotherapy unit by the same experienced staff. Immunotherapy was given following a conventional schedule, modified according the usual recommendations. Results A total of 250 adverse reactions have been recorded, resulting in a frequency of 0.84% over the total number of injections. Seventy-nine of them (32%) were systemic reactions (0.27% SR/injection). The 79 systemic reactions were observed in 60 patients (5% of the patients). The frequency of systemic reactions was significantly lower (P < 0.01) on the group of mites than on the other groups. The frequency of systemic reactions varies according to the manufacturing laboratory. In the case of mite extracts, although one of the laboratories had a lower frequency of adverse systemic reactions, it did not reach the level of statistical significance. However, in relation to pollen extracts, preparations of one of the manufacturers had a significantly lower frequency of systemic reactions. Concerning the time of occurrence, 27% of systemic reactions were delayed, thus they appeared at least 30 min after the vaccine injection, most of them due to pollen extracts. Conclusion This is a preliminary study to evaluate the factors that could facilitate the appearance of systemic reactions demonstrating that not only the composition but also the manufacturer is connected to systemic reactions. Although further studies are needed to clearly establish the influence of manufacturer on frequency and time of appearance of systemic reactions, it seems necessary to reach a wide consensus on allergen extract standardization methods. [source] Wasp venom immunotherapy induces a shift from IL-4-producing towards interferon-gamma-producing CD4+ and CD8+ T lymphocytesCLINICAL & EXPERIMENTAL ALLERGY, Issue 5 2001A. J. Schuerwegh Background Venom immunotherapy (VIT) has proven to be very effective in hymenoptera venom anaphylaxis. However, the underlying immunoregulatory mechanisms of venom immunotherapy remain poorly understood. Recent studies measured the total amount of cytokine in culture supernatans, suggesting a shift in cytokine production from Th2 to a Th1 cytokine profile during VIT. We wanted to examine the contribution of specific T lymphocyte subpopulations, which is impossible using an extracellular method to determine cytokines in supernatants. Objective The present study was designed to evaluate the effect of VIT on the percentages of type 1 (IL-2, interferon-gamma (IFN-,)) and type 2 (IL-4) CD4+ and CD8+ T lymphocytes of patients with wasp venom anaphylaxis during immunotherapy. Methods Peripheral blood mononuclear cells of 20 individuals with a history of wasp sting anaphylaxis and a positive serum wasp venom specific IgE were isolated and in vitro stimulated with phorbol-12-myristate-13-acetate and ionomycin before VIT, at the end of a 5-day semirush VIT and at 6 months during VIT. Three-colour flow cytometric analysis was used for intracellular cytokine (IL-2, IFN-,, IL-4) detection in CD4+ (CD3+CD8,) T lymphocytes and CD8+ (CD3+CD8+) T lymphocytes. Results At the end of a 5-day semirush VIT, there was a significant decrease in percentage of IL-4-producing CD4+ and CD8+ T cells, compared with cytokine-producing cells before VIT (P = 0.0002 and 0.004). After 6 months of VIT, patients showed an increased number of IL-2-producing stimulated CD4+ and CD8+ lymphocytes compared with values before VIT (P = 0.002 and P = 0.0003). A higher amount of IFN-,-producing stimulated CD4+ and CD8+ cells was found after 6 months of VIT (P = 0.001 and P = 0.0006). There was no correlation between cytokine-producing cells and specific IgE for wasp. Conclusion Venom immunotherapy induced a shift from IL-4-producing towards IFN-,-producing CD4+ as well as CD8+ T lymphocytes. [source] | ||||||||||