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Luc S De Clerck - One of the best experts on this subject based on the ideXlab platform.

  • component resolved diagnosis of Wasp yellow jacket Venom allergy
    Clinical & Experimental Allergy, 2013
    Co-Authors: Margaretha A Faber, Chris H Bridts, Josee E Leysen, Valentina Sabato, Luc S De Clerck
    Abstract:

    SummaryBackground Wasp Venom allergy is a potentially life-threatening condition with serious consequences of diagnostic error. Objective To assess whether component-resolved diagnosis, using non-glycosylated recombinant allergen components from yellow jacket can add to the diagnosis of Wasp Venom allergy. Methods In total, 148 patients with a Wasp (yellow jacket) allergy were included, 91 with unequivocal tests, 26 with double positivity of serum-specific IgE (sIgE) to both Venoms, 21 with discrepant sIgE and skin test results and finally 10 having their diagnosis only confirmed by basophil activation test (negative sIgE and skin test results). Specific IgE to recombinant species-specific allergen components Ves v 1 and Ves v 5 from yellow jacket, Api m 1 from honeybee and Ves v 5 complemented Wasp Venom were tested by ImmunoCAP. Results Overall, combined use of sIgE to rVes v 1 and rVes v 5 allowed correct diagnosis in 139 of the 148 patients (94%) and rApi m 1 was demonstrable in only one patient. Supplementing the traditional yellow jacket allergosorbent with rVes v 5 allowed to correctly diagnose Wasp allergy in patients sensitized to Ves v 5 but demonstrating a negative sIgE to Wasp Venom. Conclusion Component-resolved diagnoses with the Wasp-specific recombinant allergen components Ves v 1 and Ves v 5 is a reliable method to diagnose yellow jacket allergy and can help to take out the sting of difficult cases. However, as the number of patients with doubt after conventional tests is small, larger collaborative studies are needed to draw more definitive conclusions. Whether the rVes v 5 supplemented yellow jacket allergosorbent constitutes an asset in the diagnostic management of Wasp Venom allergy remains to be further established.

  • Component-resolved diagnosis of Wasp (yellow jacket) Venom allergy
    Clinical and Experimental Allergy, 2013
    Co-Authors: Didier G. Ebo, Milosz Faber, Chris H Bridts, Josee E Leysen, Valentina Sabato, Luc S De Clerck
    Abstract:

    BACKGROUND: Wasp Venom allergy is a potentially life-threatening condition with serious consequences of diagnostic error.\n\nOBJECTIVE: To assess whether component-resolved diagnosis, using non-glycosylated recombinant allergen components from yellow jacket can add to the diagnosis of Wasp Venom allergy.\n\nMETHODS: In total, 148 patients with a Wasp (yellow jacket) allergy were included, 91 with unequivocal tests, 26 with double positivity of serum-specific IgE (sIgE) to both Venoms, 21 with discrepant sIgE and skin test results and finally 10 having their diagnosis only confirmed by basophil activation test (negative sIgE and skin test results). Specific IgE to recombinant species-specific allergen components Ves v 1 and Ves v 5 from yellow jacket, Api m 1 from honeybee and Ves v 5 complemented Wasp Venom were tested by ImmunoCAP.\n\nRESULTS: Overall, combined use of sIgE to rVes v 1 and rVes v 5 allowed correct diagnosis in 139 of the 148 patients (94%) and rApi m 1 was demonstrable in only one patient. Supplementing the traditional yellow jacket allergosorbent with rVes v 5 allowed to correctly diagnose Wasp allergy in patients sensitized to Ves v 5 but demonstrating a negative sIgE to Wasp Venom.\n\nCONCLUSION: Component-resolved diagnoses with the Wasp-specific recombinant allergen components Ves v 1 and Ves v 5 is a reliable method to diagnose yellow jacket allergy and can help to take out the sting of difficult cases. However, as the number of patients with doubt after conventional tests is small, larger collaborative studies are needed to draw more definitive conclusions. Whether the rVes v 5 supplemented yellow jacket allergosorbent constitutes an asset in the diagnostic management of Wasp Venom allergy remains to be further established.

  • p38 mitogen activated protein kinase signal transduction in the diagnosis and follow up of immunotherapy of Wasp Venom allergy
    Cytometry Part B-clinical Cytometry, 2010
    Co-Authors: M M Verweij, Chris H Bridts, Luc S De Clerck, Kathleen J De Knop, W J Stevens
    Abstract:

    BACKGROUND: P38 mitogen-activated protein kinase (MAPK) is known to govern IgE-mediated basophil activation. Intracellular phosphorylated p38 MAPK (Pp38 MAPK) in IgE-activated basophils can be quantified flow cytometrically. OBJECTIVES: To study whether Pp38 MAPK constitutes a potential novel read-out for flow-assisted diagnosis of hymenoptera Venom allergy and to investigate whether this marker allows follow-up of successful Venom immunotherapy (VIT). METHODS: Fifty-two patients with documented Wasp Venom allergy and seven Wasp-stung asymptomatic control individuals were enrolled. Wasp Venom-induced basophil activation was analyzed flow cytometrically with anti-IgE, anti-CD63, and anti-Pp38 MAPK to assess their activation status before starting immunotherapy. To assess whether p38 MAPK constitutes a candidate marker for monitoring VIT, we repeated the basophil activation test (BAT) in 25 patients on the fifth day of a build-up immunotherapy. In addition, we investigated whether the Pp38 MAPK-based BAT could contribute in the decision of discontinuing VIT in a cross-sectional analysis in 13 patients receiving treatment for 3 years and 14 patients receiving treatment for 5 years. RESULTS: Patients exhibited a dose-dependent basophil activation with phosphorylation of p38 MAPK and upregulation of downstream CD63. In contrast, stung controls demonstrated a dose-dependent but "abrogated" signal transduction in basophils with less and shorter duration of the phosphorylation of p38 MAPK and without subsequent upregulation of CD63. When repeated after 5 days of VIT and when investigated cross-sectionally after 3 years or 5 years of maintenance therapy, no effect of VIT on the phosphorylation of p38 MAPK was demonstrable. CONCLUSIONS: This study discloses that not only basophils from patients, but also from the stung control individuals, respond to Wasp Venom stimulation with phosphorylation of p38 MAPK, although to a lesser extend. No clear effect of VIT on the phosphorylation of p38 MAPK was shown. Thus, although p38 MAPK provides an additional tool in the diagnosis of Wasp Venom allergy, it does not contribute to the decision whether to stop successful VIT. © 2010 International Clinical Cytometry Society.

  • flow assisted quantification of in vitro activated basophils in the diagnosis of Wasp Venom allergy and follow up of Wasp Venom immunotherapy
    Cytometry Part B-clinical Cytometry, 2007
    Co-Authors: M M Hagendorens, Chris H Bridts, Luc S De Clerck, A J Schuerwegh, L M N Beirens, W J Stevens
    Abstract:

    Background: Correct identification of the culprit Venom is a prerequisite for specific Venom immunotherapy (VIT). Despite the efficacy of VIT, issues as how to monitor treatment and when to discontinue maintenance therapy remain to be established. Methods: To evaluate diagnostic performances of the basophil activation test (BAT) in Wasp Venom allergy, 80 patients with a definite history of Wasp Venom anaphylaxis (systemic reactors) and 14 Waspstung asymptomatic controls (stung controls) were enrolled. Venom-induced basophil activation was analyzed flow cytometrically by double-labeling with anti-IgE and anti-CD63. Results were compared to Wasp IgE levels and results of a Venom skin test (VST). To establish whether the BAT constitutes a candidate marker to monitor VIT, the BAT was repeated in 22 patients on the 5th day of a build-up course and after 6 months of maintenance VIT. Whether the BAT could contribute in the decision of discontinuing VIT was assessed in a cross-sectional analysis in 30 patients receiving treatment for 3 years. Results: Comparison between systemic reactors and stung controls revealed a sensitivity of 86.4% and specificity of 100% for Venom IgE, and sensitivity of 81.8% for VST, respectively. In contrast to stung controls, patients demonstrated dose-dependent Venom-induced basophil activation. The BAT attained a sensitivity of 83.8% and specificity of 100%. At the end of the build-up course, no effect of VIT on the BAT was demonstrable. When the BAT was repeated after 6 months of treatment, submaximal stimulation of the cells demonstrated a significant decreased CD63 expression (P < 0.04). Patients having VIT for 3 years also demonstrated significantly lower Venom-induced CD63 expression (P < 0.001). After 3 years, 60% of the patients had a negative BAT for submaximal stimulation of the cells whereas only 17.9% of the patients had negativation of Wasp IgE. Conclusions: The BAT is a reliable instrument for the diagnosis of Wasp Venom anaphylaxis and might constitute an instrument to monitor Wasp VIT. q 2006 International Society for Analytical Cytology

  • Wasp Venom immunotherapy induces a shift from IL-4-producing towards interferon-gamma-producing CD4+ and CD8+ T lymphocytes.
    Clinical & Experimental Allergy, 2001
    Co-Authors: A J Schuerwegh, Chris H Bridts, Luc S De Clerck, W. J. Stevens
    Abstract:

    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-gamma)) 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-gamma, 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-gamma-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-gamma-producing CD4+ as well as CD8+ T lymphocytes.

Chris H Bridts - One of the best experts on this subject based on the ideXlab platform.

  • component resolved diagnosis of Wasp yellow jacket Venom allergy
    Clinical & Experimental Allergy, 2013
    Co-Authors: Margaretha A Faber, Chris H Bridts, Josee E Leysen, Valentina Sabato, Luc S De Clerck
    Abstract:

    SummaryBackground Wasp Venom allergy is a potentially life-threatening condition with serious consequences of diagnostic error. Objective To assess whether component-resolved diagnosis, using non-glycosylated recombinant allergen components from yellow jacket can add to the diagnosis of Wasp Venom allergy. Methods In total, 148 patients with a Wasp (yellow jacket) allergy were included, 91 with unequivocal tests, 26 with double positivity of serum-specific IgE (sIgE) to both Venoms, 21 with discrepant sIgE and skin test results and finally 10 having their diagnosis only confirmed by basophil activation test (negative sIgE and skin test results). Specific IgE to recombinant species-specific allergen components Ves v 1 and Ves v 5 from yellow jacket, Api m 1 from honeybee and Ves v 5 complemented Wasp Venom were tested by ImmunoCAP. Results Overall, combined use of sIgE to rVes v 1 and rVes v 5 allowed correct diagnosis in 139 of the 148 patients (94%) and rApi m 1 was demonstrable in only one patient. Supplementing the traditional yellow jacket allergosorbent with rVes v 5 allowed to correctly diagnose Wasp allergy in patients sensitized to Ves v 5 but demonstrating a negative sIgE to Wasp Venom. Conclusion Component-resolved diagnoses with the Wasp-specific recombinant allergen components Ves v 1 and Ves v 5 is a reliable method to diagnose yellow jacket allergy and can help to take out the sting of difficult cases. However, as the number of patients with doubt after conventional tests is small, larger collaborative studies are needed to draw more definitive conclusions. Whether the rVes v 5 supplemented yellow jacket allergosorbent constitutes an asset in the diagnostic management of Wasp Venom allergy remains to be further established.

  • Component-resolved diagnosis of Wasp (yellow jacket) Venom allergy
    Clinical and Experimental Allergy, 2013
    Co-Authors: Didier G. Ebo, Milosz Faber, Chris H Bridts, Josee E Leysen, Valentina Sabato, Luc S De Clerck
    Abstract:

    BACKGROUND: Wasp Venom allergy is a potentially life-threatening condition with serious consequences of diagnostic error.\n\nOBJECTIVE: To assess whether component-resolved diagnosis, using non-glycosylated recombinant allergen components from yellow jacket can add to the diagnosis of Wasp Venom allergy.\n\nMETHODS: In total, 148 patients with a Wasp (yellow jacket) allergy were included, 91 with unequivocal tests, 26 with double positivity of serum-specific IgE (sIgE) to both Venoms, 21 with discrepant sIgE and skin test results and finally 10 having their diagnosis only confirmed by basophil activation test (negative sIgE and skin test results). Specific IgE to recombinant species-specific allergen components Ves v 1 and Ves v 5 from yellow jacket, Api m 1 from honeybee and Ves v 5 complemented Wasp Venom were tested by ImmunoCAP.\n\nRESULTS: Overall, combined use of sIgE to rVes v 1 and rVes v 5 allowed correct diagnosis in 139 of the 148 patients (94%) and rApi m 1 was demonstrable in only one patient. Supplementing the traditional yellow jacket allergosorbent with rVes v 5 allowed to correctly diagnose Wasp allergy in patients sensitized to Ves v 5 but demonstrating a negative sIgE to Wasp Venom.\n\nCONCLUSION: Component-resolved diagnoses with the Wasp-specific recombinant allergen components Ves v 1 and Ves v 5 is a reliable method to diagnose yellow jacket allergy and can help to take out the sting of difficult cases. However, as the number of patients with doubt after conventional tests is small, larger collaborative studies are needed to draw more definitive conclusions. Whether the rVes v 5 supplemented yellow jacket allergosorbent constitutes an asset in the diagnostic management of Wasp Venom allergy remains to be further established.

  • p38 mitogen activated protein kinase signal transduction in the diagnosis and follow up of immunotherapy of Wasp Venom allergy
    Cytometry Part B-clinical Cytometry, 2010
    Co-Authors: M M Verweij, Chris H Bridts, Luc S De Clerck, Kathleen J De Knop, W J Stevens
    Abstract:

    BACKGROUND: P38 mitogen-activated protein kinase (MAPK) is known to govern IgE-mediated basophil activation. Intracellular phosphorylated p38 MAPK (Pp38 MAPK) in IgE-activated basophils can be quantified flow cytometrically. OBJECTIVES: To study whether Pp38 MAPK constitutes a potential novel read-out for flow-assisted diagnosis of hymenoptera Venom allergy and to investigate whether this marker allows follow-up of successful Venom immunotherapy (VIT). METHODS: Fifty-two patients with documented Wasp Venom allergy and seven Wasp-stung asymptomatic control individuals were enrolled. Wasp Venom-induced basophil activation was analyzed flow cytometrically with anti-IgE, anti-CD63, and anti-Pp38 MAPK to assess their activation status before starting immunotherapy. To assess whether p38 MAPK constitutes a candidate marker for monitoring VIT, we repeated the basophil activation test (BAT) in 25 patients on the fifth day of a build-up immunotherapy. In addition, we investigated whether the Pp38 MAPK-based BAT could contribute in the decision of discontinuing VIT in a cross-sectional analysis in 13 patients receiving treatment for 3 years and 14 patients receiving treatment for 5 years. RESULTS: Patients exhibited a dose-dependent basophil activation with phosphorylation of p38 MAPK and upregulation of downstream CD63. In contrast, stung controls demonstrated a dose-dependent but "abrogated" signal transduction in basophils with less and shorter duration of the phosphorylation of p38 MAPK and without subsequent upregulation of CD63. When repeated after 5 days of VIT and when investigated cross-sectionally after 3 years or 5 years of maintenance therapy, no effect of VIT on the phosphorylation of p38 MAPK was demonstrable. CONCLUSIONS: This study discloses that not only basophils from patients, but also from the stung control individuals, respond to Wasp Venom stimulation with phosphorylation of p38 MAPK, although to a lesser extend. No clear effect of VIT on the phosphorylation of p38 MAPK was shown. Thus, although p38 MAPK provides an additional tool in the diagnosis of Wasp Venom allergy, it does not contribute to the decision whether to stop successful VIT. © 2010 International Clinical Cytometry Society.

  • flow assisted quantification of in vitro activated basophils in the diagnosis of Wasp Venom allergy and follow up of Wasp Venom immunotherapy
    Cytometry Part B-clinical Cytometry, 2007
    Co-Authors: M M Hagendorens, Chris H Bridts, Luc S De Clerck, A J Schuerwegh, L M N Beirens, W J Stevens
    Abstract:

    Background: Correct identification of the culprit Venom is a prerequisite for specific Venom immunotherapy (VIT). Despite the efficacy of VIT, issues as how to monitor treatment and when to discontinue maintenance therapy remain to be established. Methods: To evaluate diagnostic performances of the basophil activation test (BAT) in Wasp Venom allergy, 80 patients with a definite history of Wasp Venom anaphylaxis (systemic reactors) and 14 Waspstung asymptomatic controls (stung controls) were enrolled. Venom-induced basophil activation was analyzed flow cytometrically by double-labeling with anti-IgE and anti-CD63. Results were compared to Wasp IgE levels and results of a Venom skin test (VST). To establish whether the BAT constitutes a candidate marker to monitor VIT, the BAT was repeated in 22 patients on the 5th day of a build-up course and after 6 months of maintenance VIT. Whether the BAT could contribute in the decision of discontinuing VIT was assessed in a cross-sectional analysis in 30 patients receiving treatment for 3 years. Results: Comparison between systemic reactors and stung controls revealed a sensitivity of 86.4% and specificity of 100% for Venom IgE, and sensitivity of 81.8% for VST, respectively. In contrast to stung controls, patients demonstrated dose-dependent Venom-induced basophil activation. The BAT attained a sensitivity of 83.8% and specificity of 100%. At the end of the build-up course, no effect of VIT on the BAT was demonstrable. When the BAT was repeated after 6 months of treatment, submaximal stimulation of the cells demonstrated a significant decreased CD63 expression (P < 0.04). Patients having VIT for 3 years also demonstrated significantly lower Venom-induced CD63 expression (P < 0.001). After 3 years, 60% of the patients had a negative BAT for submaximal stimulation of the cells whereas only 17.9% of the patients had negativation of Wasp IgE. Conclusions: The BAT is a reliable instrument for the diagnosis of Wasp Venom anaphylaxis and might constitute an instrument to monitor Wasp VIT. q 2006 International Society for Analytical Cytology

  • Wasp Venom immunotherapy induces a shift from IL-4-producing towards interferon-gamma-producing CD4+ and CD8+ T lymphocytes.
    Clinical & Experimental Allergy, 2001
    Co-Authors: A J Schuerwegh, Chris H Bridts, Luc S De Clerck, W. J. Stevens
    Abstract:

    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-gamma)) 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-gamma, 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-gamma-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-gamma-producing CD4+ as well as CD8+ T lymphocytes.

W J Stevens - One of the best experts on this subject based on the ideXlab platform.

  • p38 mitogen activated protein kinase signal transduction in the diagnosis and follow up of immunotherapy of Wasp Venom allergy
    Cytometry Part B-clinical Cytometry, 2010
    Co-Authors: M M Verweij, Chris H Bridts, Luc S De Clerck, Kathleen J De Knop, W J Stevens
    Abstract:

    BACKGROUND: P38 mitogen-activated protein kinase (MAPK) is known to govern IgE-mediated basophil activation. Intracellular phosphorylated p38 MAPK (Pp38 MAPK) in IgE-activated basophils can be quantified flow cytometrically. OBJECTIVES: To study whether Pp38 MAPK constitutes a potential novel read-out for flow-assisted diagnosis of hymenoptera Venom allergy and to investigate whether this marker allows follow-up of successful Venom immunotherapy (VIT). METHODS: Fifty-two patients with documented Wasp Venom allergy and seven Wasp-stung asymptomatic control individuals were enrolled. Wasp Venom-induced basophil activation was analyzed flow cytometrically with anti-IgE, anti-CD63, and anti-Pp38 MAPK to assess their activation status before starting immunotherapy. To assess whether p38 MAPK constitutes a candidate marker for monitoring VIT, we repeated the basophil activation test (BAT) in 25 patients on the fifth day of a build-up immunotherapy. In addition, we investigated whether the Pp38 MAPK-based BAT could contribute in the decision of discontinuing VIT in a cross-sectional analysis in 13 patients receiving treatment for 3 years and 14 patients receiving treatment for 5 years. RESULTS: Patients exhibited a dose-dependent basophil activation with phosphorylation of p38 MAPK and upregulation of downstream CD63. In contrast, stung controls demonstrated a dose-dependent but "abrogated" signal transduction in basophils with less and shorter duration of the phosphorylation of p38 MAPK and without subsequent upregulation of CD63. When repeated after 5 days of VIT and when investigated cross-sectionally after 3 years or 5 years of maintenance therapy, no effect of VIT on the phosphorylation of p38 MAPK was demonstrable. CONCLUSIONS: This study discloses that not only basophils from patients, but also from the stung control individuals, respond to Wasp Venom stimulation with phosphorylation of p38 MAPK, although to a lesser extend. No clear effect of VIT on the phosphorylation of p38 MAPK was shown. Thus, although p38 MAPK provides an additional tool in the diagnosis of Wasp Venom allergy, it does not contribute to the decision whether to stop successful VIT. © 2010 International Clinical Cytometry Society.

  • flow assisted quantification of in vitro activated basophils in the diagnosis of Wasp Venom allergy and follow up of Wasp Venom immunotherapy
    Cytometry Part B-clinical Cytometry, 2007
    Co-Authors: M M Hagendorens, Chris H Bridts, Luc S De Clerck, A J Schuerwegh, L M N Beirens, W J Stevens
    Abstract:

    Background: Correct identification of the culprit Venom is a prerequisite for specific Venom immunotherapy (VIT). Despite the efficacy of VIT, issues as how to monitor treatment and when to discontinue maintenance therapy remain to be established. Methods: To evaluate diagnostic performances of the basophil activation test (BAT) in Wasp Venom allergy, 80 patients with a definite history of Wasp Venom anaphylaxis (systemic reactors) and 14 Waspstung asymptomatic controls (stung controls) were enrolled. Venom-induced basophil activation was analyzed flow cytometrically by double-labeling with anti-IgE and anti-CD63. Results were compared to Wasp IgE levels and results of a Venom skin test (VST). To establish whether the BAT constitutes a candidate marker to monitor VIT, the BAT was repeated in 22 patients on the 5th day of a build-up course and after 6 months of maintenance VIT. Whether the BAT could contribute in the decision of discontinuing VIT was assessed in a cross-sectional analysis in 30 patients receiving treatment for 3 years. Results: Comparison between systemic reactors and stung controls revealed a sensitivity of 86.4% and specificity of 100% for Venom IgE, and sensitivity of 81.8% for VST, respectively. In contrast to stung controls, patients demonstrated dose-dependent Venom-induced basophil activation. The BAT attained a sensitivity of 83.8% and specificity of 100%. At the end of the build-up course, no effect of VIT on the BAT was demonstrable. When the BAT was repeated after 6 months of treatment, submaximal stimulation of the cells demonstrated a significant decreased CD63 expression (P < 0.04). Patients having VIT for 3 years also demonstrated significantly lower Venom-induced CD63 expression (P < 0.001). After 3 years, 60% of the patients had a negative BAT for submaximal stimulation of the cells whereas only 17.9% of the patients had negativation of Wasp IgE. Conclusions: The BAT is a reliable instrument for the diagnosis of Wasp Venom anaphylaxis and might constitute an instrument to monitor Wasp VIT. q 2006 International Society for Analytical Cytology

  • Evolution of lymphocyte transformation to Wasp Venom antigen during immunotherapy for Wasp Venom anaphylaxis
    Clinical & Experimental Allergy, 1998
    Co-Authors: W J Stevens, Chris H Bridts, Luc S De Clerck, C. M. De Gendt, A. V. Mertens
    Abstract:

    Background Venom immunotherapy (VIT) has proven to be safe and effective in Wasp Venom anaphylaxis. However, there are no good parameters to indicate when to stop Venom immunotherapy. Objective To evaluate the relationship of the lymphocyte transformation test (LTT) to history and specific IgE determination, and to address the time course of lymphocyte transformation responses to Wasp (Vespula) Venom during VIT and the possible utility of LTT to determine the duration of therapy. Methods Peripheral blood mononuclear cells (PBMCs) of 18 individuals with a history of Wasp sting anaphylaxis and a positive serum-Venom-specific IgE, were stimulated with Wasp Venom before immunotherapy, at the end of a 5-day semi-rush immunotherapy and at 24 months during Venom immunotherapy. Results, expressed as stimulation index (SI), were compared with the SI in seven asymptomatic stung controls. Results In controls the median (minimum–maximum) of the SI were 2.39 (0.52–3.39) before therapy and 2.39 (1.12–6.02) when repeated after 24 months. For patients the median (minimum–maximum) of the SI were 10.13 (1.19–44.88) before immunotherapy (d0), 2.73 (0.67–12.03) at the end of the build-up immunotherapy (d5) and 4.21 (0.88-14.66) at the end of 24 months of maintenance therapy (m24). The proliferation responses in vespid-allergic patients were significantly higher than in stung controls (P = 0.006) but only13/18 patients showed a positive LTT result before the start of immunotherapy (sensitivity of the LTT 72%). When the LTT was repeated after a 5 day build-up hyposensitization course the SI significantly dropped as compared to the pre-treatment levels (P = 0.002). The SI of the LTT was negative in eight out of 18 patients at 24 months and the median values were significantly lower than before therapy (P = 0.03). Conclusions Although, in the absence of sting challenge data it is not possible to draw conclusions about the predictive value of the LTT, our data may suggest that abolition of the LTT during VIT might indicate clinical insensitivity. Further studies, comparing the results of sting challenges, with the results of lymphocyte transformation will be necessary in order to evaluate the role of LTT in stopping immunotherapy.

Edzard Spillner - One of the best experts on this subject based on the ideXlab platform.

  • decline of ves v 5 specific blocking capacity in Wasp Venom allergic patients after stopping allergen immunotherapy
    Allergy, 2015
    Co-Authors: Christian Mobs, Simon Blank, Edzard Spillner, J Muller, A Rudzio, Julia Pickert, Thilo Jakob, Wolfgang Pfützner
    Abstract:

    : While allergen-specific immunotherapy (AIT) is very efficient in hymenoptera Venom (HV)-allergic patients, long-term outcome after finishing AIT is not well investigated, especially regarding mechanisms that are suggested to contribute to allergen-specific tolerance. Here, we analyse the Ves v 5-inhibitory activity of sera from Wasp Venom-allergic patients using the novel cell-free enzyme-linked immunosorbent facilitated antigen binding (ELIFAB) assay. Compared to pre-AIT, sera from patients undergoing AIT displayed an increased ability to inhibit Ves v 5 binding by IgE antibodies. In contrast, this inhibitory activity was reduced in patients having finished AIT 5-12 years ago. Allergen-blocking capacity correlated with serum concentrations of Ves v 5-specific IgG4 which rose during AIT but almost reached pretreatment levels in patients who had stopped AIT more than 5 years ago. These data raise questions about how long allergen tolerance is maintained in AIT-treated HV-allergic patients and suggest that the ELIFAB assay might be an easy-to-use tool assessing long-term tolerance in patients treated with HV-AIT.

  • Decline of Ves v 5‐specific blocking capacity in Wasp Venom‐allergic patients after stopping allergen immunotherapy
    Allergy, 2015
    Co-Authors: Christian Mobs, Simon Blank, Edzard Spillner, J Muller, A Rudzio, Julia Pickert, Thilo Jakob, Wolfgang Pfützner
    Abstract:

    : While allergen-specific immunotherapy (AIT) is very efficient in hymenoptera Venom (HV)-allergic patients, long-term outcome after finishing AIT is not well investigated, especially regarding mechanisms that are suggested to contribute to allergen-specific tolerance. Here, we analyse the Ves v 5-inhibitory activity of sera from Wasp Venom-allergic patients using the novel cell-free enzyme-linked immunosorbent facilitated antigen binding (ELIFAB) assay. Compared to pre-AIT, sera from patients undergoing AIT displayed an increased ability to inhibit Ves v 5 binding by IgE antibodies. In contrast, this inhibitory activity was reduced in patients having finished AIT 5-12 years ago. Allergen-blocking capacity correlated with serum concentrations of Ves v 5-specific IgG4 which rose during AIT but almost reached pretreatment levels in patients who had stopped AIT more than 5 years ago. These data raise questions about how long allergen tolerance is maintained in AIT-treated HV-allergic patients and suggest that the ELIFAB assay might be an easy-to-use tool assessing long-term tolerance in patients treated with HV-AIT.

  • basophil activation test using recombinant allergens highly specific diagnostic method complementing routine tests in Wasp Venom allergy
    PLOS ONE, 2014
    Co-Authors: Lukas Balzer, Davide Pennino, Simon Blank, Henning Seismann, U Darsow, Mathias Schnedler, M Mcintyre, Markus Ollert, Stephen R Durham, Edzard Spillner
    Abstract:

    Background Skin testing can expose allergic subjects to potential systemic reactions, sensitization against unrelated proteins, and increased risk of future sting reactions. Therefore the continuous improvement of in vitro diagnostic methods is desirable. Recombinant allergens have been shown to improve the sensitivity of specific IgE (sIgE) detection in vitro whilst no data is available regarding their application and reliability in basophil activation test (BAT). Here we aimed to compare the specificity and sensitivity of recombinant allergens Ves v 1, Ves v 2, Ves v 3 and Ves v 5 in both specific IgE (sIgE) detection in vitro and basophil activation test. Methods sIgE detection by ELISA or ImmunoCAP and BAT towards the panel of recombinant allergens Ves v 1, Ves v 2, Ves v 3 and Ves v 5 were performed in 43 Wasp Venom allergic patients with a history of anaphylactic reaction and sIgE seropositivity, as well as 17 controls defined as subjects with a history of repetitive Wasp stings but absence of any allergic symptom. Results The BAT performed with the recombinant allergens Ves v 1, Ves v 2, Ves v 3 and Ves v 5 markedly improved the specificity of diagnosis in Wasp Venom allergic subjects when compared to the respective sIgE detection in serum. Conclusions BAT performed with the recombinant allergens Ves v 5, Ves v 3 and Ves v 1 provides an emerging highly specific in vitro method for the detection of Wasp Venom allergy, compared to the sIgE detection. Recombinant allergens applied to BAT represent a step forward in developing reliable in vitro tests for specific diagnosis of allergy.

Wolfgang Pfützner - One of the best experts on this subject based on the ideXlab platform.

  • decline of ves v 5 specific blocking capacity in Wasp Venom allergic patients after stopping allergen immunotherapy
    Allergy, 2015
    Co-Authors: Christian Mobs, Simon Blank, Edzard Spillner, J Muller, A Rudzio, Julia Pickert, Thilo Jakob, Wolfgang Pfützner
    Abstract:

    : While allergen-specific immunotherapy (AIT) is very efficient in hymenoptera Venom (HV)-allergic patients, long-term outcome after finishing AIT is not well investigated, especially regarding mechanisms that are suggested to contribute to allergen-specific tolerance. Here, we analyse the Ves v 5-inhibitory activity of sera from Wasp Venom-allergic patients using the novel cell-free enzyme-linked immunosorbent facilitated antigen binding (ELIFAB) assay. Compared to pre-AIT, sera from patients undergoing AIT displayed an increased ability to inhibit Ves v 5 binding by IgE antibodies. In contrast, this inhibitory activity was reduced in patients having finished AIT 5-12 years ago. Allergen-blocking capacity correlated with serum concentrations of Ves v 5-specific IgG4 which rose during AIT but almost reached pretreatment levels in patients who had stopped AIT more than 5 years ago. These data raise questions about how long allergen tolerance is maintained in AIT-treated HV-allergic patients and suggest that the ELIFAB assay might be an easy-to-use tool assessing long-term tolerance in patients treated with HV-AIT.

  • Decline of Ves v 5‐specific blocking capacity in Wasp Venom‐allergic patients after stopping allergen immunotherapy
    Allergy, 2015
    Co-Authors: Christian Mobs, Simon Blank, Edzard Spillner, J Muller, A Rudzio, Julia Pickert, Thilo Jakob, Wolfgang Pfützner
    Abstract:

    : While allergen-specific immunotherapy (AIT) is very efficient in hymenoptera Venom (HV)-allergic patients, long-term outcome after finishing AIT is not well investigated, especially regarding mechanisms that are suggested to contribute to allergen-specific tolerance. Here, we analyse the Ves v 5-inhibitory activity of sera from Wasp Venom-allergic patients using the novel cell-free enzyme-linked immunosorbent facilitated antigen binding (ELIFAB) assay. Compared to pre-AIT, sera from patients undergoing AIT displayed an increased ability to inhibit Ves v 5 binding by IgE antibodies. In contrast, this inhibitory activity was reduced in patients having finished AIT 5-12 years ago. Allergen-blocking capacity correlated with serum concentrations of Ves v 5-specific IgG4 which rose during AIT but almost reached pretreatment levels in patients who had stopped AIT more than 5 years ago. These data raise questions about how long allergen tolerance is maintained in AIT-treated HV-allergic patients and suggest that the ELIFAB assay might be an easy-to-use tool assessing long-term tolerance in patients treated with HV-AIT.

  • Unusual neurological reaction in a patient allergic to Wasp Venom
    The Journal of Allergy and Clinical Immunology, 2004
    Co-Authors: Wolfgang Pfützner, Andrea Niedermeier, Franziska Ruëff, Bernhard Przybilla
    Abstract:

    Abstract Rationale Neurological complications due to Hymenoptera Venom are rather uncommon. We studied a 37-year-old female who had experienced an anaphylactic reaction encompassing urticaria, asthma, vomiting and cardiovascular disturbances to a Wasp sting and who developed aphasia and motor control disturbances during Wasp Venom immunotherapy (VIT). Methods To determine the nature of the reaction pattern in our patient allergological, neurological and psychiatric examinations were performed. Results Skin tests and measurements of specific serum IgE confirmed the sensitization against Wasp Venom. After a sting challenge with a living Wasp the patient developed shivers, became adynamic and was unable to speak or react to simple requests. Symptoms took several hours to resolve after intravenous treatment with a corticosteroid and an antihistamine. A similar reaction occurred after a placebo injection with 0.9% saline given to the patient with the information that it was Wasp Venom as continuation of her VIT. Neurological examination including magnetic resonance imaging of the brain failed to show any abnormalities. A careful evaluation by a psychiatrist revealed that the patient's reaction was due to a neurotic conflict. Conclusions Psychiatric disturbances have to be considered among the differential diagnoses in patients allergic to Hymenoptera Venom showing unusual neurological complications to Venom exposure. In these patients, placebo testing might help determining the right diagnosis.