Importance of basophil activation testing in insect venom allergy
© Kosnik and Korosec; licensee BioMed Central Ltd. 2009
Received: 5 November 2009
Accepted: 1 December 2009
Published: 1 December 2009
Venom immunotherapy (VIT) is the only effective treatment for prevention of serious allergic reactions to bee and wasp stings in sensitized individuals. However, there are still many questions and controversies regarding immunotherapy, like selection of the appropriate allergen, safety and long term efficacy.
Literature review was performed to address the role of basophil activation test (BAT) in diagnosis of venom allergy.
In patients with positive skin tests or specific IgE to both honeybee and wasp venom, IgE inhibition test can identify sensitizing allergen only in around 15% and basophil activation test increases the identification rate to around one third of double positive patients. BAT is also diagnostic in majority of patients with systemic reactions after insect stings and no detectable IgE. High basophil sensitivity to allergen is associated with a risk of side effects during VIT. Persistence of high basophil sensitivity also predicts a treatment failure of VIT.
BAT is a useful tool for better selection of allergen for immunotherapy, for identification of patients prone to side effects and patients who might be treatment failures. However, long term studies are needed to evaluate the accuracy of the test.
Up to 0.1% of the population suffers from severe anaphylaxis after Hymenoptera insect sting. The prevalence is even higher in beekeepers, where can exceed 4% . Venom immunotherapy (VIT) is the only effective treatment for prevention of serious allergic reactions to bee and wasp stings in sensitized individuals. However, there are still many questions and controversies regarding immunotherapy, like selection of the appropriate venom in patients with double positive tests or of patients with allergic reactions following European hornet stings, patients with negative sIgE and skin tests, detecting the patients at risk for side effects during immunotherapy and detecting the patients at risk of relapse after stopping immunotherapy .
Patients with positive allergy tests to both honeybee and wasp venom
Up to 50% of patients with sting reactions have positive routine diagnostic tests (skin tests, specific IgE) to both honeybee and wasp venom. True double sensitization and cross-reactivity must be considered as a cause of the double positivity and diagnosed in this group of patients . Cross-reactivity is possible on the protein level most often through venom hyaluronidases or through carbohydrates epitopes (CCD) [4, 5]. Distinguishing between double sensitization and cross-reactivity is crucial for the choice of a proper allergen for specific immunotherapy in patients who didn't recognize the culprit insect . Namely, patients should be treated with the venom, which induced sensitization. Immunotherapy with the venom to which a patient is not primarily sensitised can lead to an incomplete protection and treatment failure. On the other hand, treatment with a cross-reactive venom only or a mixture of venoms can lead to the formation of sIgE against epitopes to which the patient was not sensitised prior to immunotherapy [7, 8].
If double sensitization is proven in a patient, who did not recognize the culprit insect, immunotherapy should be performed with both venoms; if cross - reactivity is the case, immunotherapy should be performed only with the venom that caused sensitization. Using specific IgE inhibition tests, Straumann was able to identify the insect that caused sensitisation in 4 out of 24 double positive patients . We performed basophil activation tests (BAT) in 25 bee and wasp double positive patients and were able to characterize primary sensitization in one third of them (nearly all were found to be wasp allergic) . BAT is a flow cytometry based test, which measures basophil activation markers like CD63 on surface of basophils after cells are stimulated in-vitro with allergen. We found some additional benefit of BAT over sIgE as basophils are not activated by clinically unimportant sIgE antibodies against CCD. BAT was shown to have higher specificity compared to sIgE, retaining higher sensitivity compared to skin tests. Moreover, the BAT test was feasible also in patients with very low level of sIgE, where inhibition tests were not possible.
Immunotherapy of patients with allergic reactions following European hornet stings
In Europe, wasp stings are responsible for most Vespidae venom allergic reactions and only occasional reactions are caused by European hornet (Vespa crabro) stings. However, those reactions are very likely to be severe: the relative risk for life-threatening reactions after a Vespa crabro sting is about three times higher than it is for a honeybee or yellow jacket sting . Those patients usually have positive skin tests and specific IgE to all Vespoidea venoms (Vespula germanica, Vespa crabro and also paper wasp [Polistes]).
In order to distinguish primary sensitisation from cross-reactivity, we performed cross inhibition tests in 24 consecutive patients who experienced anaphylactic reaction after European hornet stings: 17/24 patients were sensitised with only wasp (Vespula germanica) venom, 2/24 with completely cross-reactive epitopes, 1 with only European hornet venom and 4 with separate epitopes of both venoms . We concluded that in Europe at least 70% of patients that experienced a systemic allergic reaction after European hornet stings were actually allergic to wasp venom. The logical conclusion from this observation would be that Vespula germanica venom remains the most appropriate immunotherapeutic agent for the majority of those patients.
Anaphylaxis in patients with negative allergy tests
Although sIgE are believed to be the cause of allergic reactions after Hymenoptera insect stings, around 4% of patients with repeated systemic reactions and no detectable IgE [12, 13]. Current guidelines for VIT suggest that immunotherapy should be performed only in patients with an IgE-mediated systemic reaction , but opinions about the diagnosis and treatment of patients with systemic reaction without IgE vary widely . Some have proposed submitting every patient with a history of Hymenoptera sting allergy and negative allergy tests to a provocation test . Negative skin test and no specific IgE may indicate a non-allergic reaction or a limited diagnostic sensitivity of the test. An alternative mechanism that could activate mast cells in the absence of sIgE is complement activation and the generation of anaphylatoxin C5a [15, 16].
However, we found that 75% of 47 sIgE negative patients had a positive reaction in the flow cytometry based basophil activation test . Even better results were shown by Ebo, who was able to identify sensitisation with a BAT test in 7 out of 7 sIgE negative patients . The limitation of those studies is that due to ethical reasons the clinical history and not a sting challenge was used as a gold standard. However it has been shown that BAT test very rarely gives false positive results .
Safety of VIT
In different immunotherapy protocols a cumulative dose of 100 μg of venom (corresponding to 2 honeybee or 10 wasp stings) is reached in few hours or days with no allergic reactions in the majority of patients, however at least 15% of patients exhibit systemic allergic reactions [20, 21]. We investigated whether adult patients prone to systemic reaction during immunotherapy could be identified on the basis of basophil sensitivity to allergen . We expressed the sensitivity as a ratio between basophil response to two concentrations of allergen. The first concentration (0.1 μg/ml) was shown in previous experiments as submaximal, eliciting only a partial activation of basophils in majority of tested subjects, and the second concentration (1 μg/ml) was maximal and elicited a complete activation of basophils in all responding subjects (it has to be stressed, that basophils of about 5% of patients do not respond at all to stimulation, and those patients are not suitable for BAT test). For each patient we calculated the ratio between basophil CD63 expression after stimulation with allergen in a concentration 0.1 and 1 μg/ml (0.1/1 ratio). Twelve out of 34 patients had reaction to VIT. In those 12 patients median 0.1/1 ratio was 0,99 (range: 0.17-1.95) Side-effects occurred in all patients with 0.1/1 ratios over 0.92. In contrast, in 22 patients with no side effects, the median 0.1/1 ratio was 0.25 (range: 0.02-0.92). These concentration-dependent activation ratios were significantly different between the groups with and without side reactions (P < 0.0001). Our results suggest that high basophil sensitivity to allergen is significantly associated with a risk of side effects to VIT. Similar results were obtained also in the children . In the same study we showed that an elevated basal tryptase level was not a predicting factor for side effects of VIT .
Effectiveness of VIT
Long-term effectiveness after stopping the treatment is less reliable: in a Swiss study, 16% of bee allergic patients and 7.5% of wasp allergic patients treated for 3 to 7 years developed systemic reactions after stopping VIT; most reactions were mild, but there was a tendency for an increase in the severity of reactions after repeated re-stinging . Moreover, a fatal reaction 9 years after the discontinuation of immunotherapy was recently described . Some risk factors for relapse after immunotherapy are recognized :
Bee venom allergy
Severe pre-treatment reaction
Reaction to VIT injection
Reaction during VIT
Duration of VIT < 5 years
Repeated re-stings after stopping VIT
Patients with reactions during immunotherapy are encouraged to receive immunotherapy indefinitely.
In our survey 229 patients treated with VIT between 1984 and 2004 were sent a questionnaire inquiring whether they had been stung by an insect to which the VIT had been directed . 79% received VIT for more than 3 years and 55% were stung after discontinuing VIT. At the time of the first sting after stopping VIT, 8 (8%) had a systemic reaction. There were 40 patients who were stung more than once after ending VIT, among whom 7 (17.5%) experienced reactions of greater severity with the subsequent stings. All patients reported that their reactions after ending VIT were milder than before treatment. The likelihood of systemic reactions to stings was almost identical in patients treated for either more than or less than 3 years with VIT. Furthermore, patients who reacted after discontinuation of immunotherapy had higher basophil sensitivity (the sensitivity was comparable to a group of patients without immunotherapy) compared to a group of protected patients .
Venom immunotherapy is very, but not completely, effective. However, managing patients with venom hypersensitivity has become less straightforward than it seemed to be some time ago. Diagnostic tests may be misleading and could pose problems regarding the selection of the appropriate venom for immunotherapy. The mechanisms of tolerance during first days of VIT are still to be documented. The long-term effectiveness of VIT is questionable. The basophil activation test appears to be a useful tool for better selection of allergen for immunotherapy, for identification of patients prone to side effects and patients who might be treatment failures. However, more long term studies are needed to evaluate the accuracy of the test.
- Münstedt K, Hellner M, Winter D, von Georgi R: Allergy to bee venom in beekeepers in Germany. J Investig Allergol Clin Immunol. 2008, 18: 100-5.PubMedGoogle Scholar
- Diwakar L, Noorani S, Huissoon AP, Frew AJ, Krishna MT: Practice of venom immunotherapy in the United Kingdom: a national audit and review of literature. Clin Exp Allergy. 2008, 38: 1651-8. 10.1111/j.1365-2222.2008.03044.x.View ArticlePubMedGoogle Scholar
- Straumann F, Bucher C, Wütrich B: Double sensitization to honeybee and wasp venom: immunotherapy with one or with both venoms? Value of FEIA inhibition for the identification of the cross-reacting IgE antibodies in double-sensitized patients to honeybee and wasp venom. Int Arch Allergy Immunol. 2000, 123: 268-74. 10.1159/000024453.View ArticlePubMedGoogle Scholar
- Wypych JI, Abeyounis CJ, Reisman RE: Analysis of differing patterns of cross-reactivity of honeybee and yellow jacket venom-specific IgE: use of purified venom fractions. Int Arch Allergy Appl Immunol. 1989, 89: 60-6. 10.1159/000234924.View ArticlePubMedGoogle Scholar
- Hemmer W, Focke M, Kolarich D, Wilson IB, Altmann F, Wohrl S, Gotz M, Jarisch R: Antibody binding to venom carbohydrates is a frequent cause for double positivity to honeybee and yellow jacket venom in patients with stinging-insect allergy. J Allergy Clin Immunol. 2001, 108: 1045-52. 10.1067/mai.2001.120013.View ArticlePubMedGoogle Scholar
- Bonifazi F, Jutel M, Biló BM, Birnbaum J, Muller U, EAACI Interest Group on Insect Venom Hypersensitivity: Prevention and treatment of hymenoptera venom allergy: guidelines for clinical practice. Allergy. 2005, 60: 1459-70. 10.1111/j.1398-9995.2005.00960.x.View ArticlePubMedGoogle Scholar
- Modrzyński M, Zawisza E: Possible induction of oral allergy syndrome during specific immunotherapy in patients sensitive to tree pollen. Med Sci Monit. 2005, 11: CR351-355.PubMedGoogle Scholar
- Juarez C, Blanca M, Miranda A, Fernandez J, Sanchez F, Carmona MJ, Avila MJ, Fernandez S, Fernandez J, Terrados S: Specific IgE antibodies to vespids in the course of immunotherpay with Vespula germanica administered to patients sensitized to Polistes dominulus. Allergy. 47: 299-302. 10.1111/j.1398-9995.1992.tb02057.x.
- Peternelj A, Šilar M, Eržen R, Bajrovič N, Mušič E, Košnik M, Korošec P: Basophil activation test (BAT) in »in vitro« diagnosis of hymenoptera venom hypersensitivity. Zdravn Vest. 2008, 77: 183-7.Google Scholar
- Antonicelli L, Bilò MB, Napoli G, Farabollini B, Bonifazi F: European hornet (Vespa crabro) sting: a new risk factor for life-threatening reaction in hymenoptera allergic patients?. Eur Ann Allergy Clin Immunol. 2003, 35: 199-203.PubMedGoogle Scholar
- Kosnik M, Korosec P, Silar M, Music E, Erzen R: Wasp venom is appropriate for immunotherapy of patients with allergic reaction to the European hornet sting. Croat Med J. 2002, 43: 25-7.PubMedGoogle Scholar
- Kosnik M: Anaphylaxis to venom without IgE antibody. Allergy. 2000, 55: 676-7. 10.1034/j.1398-9995.2000.00691.x.View ArticlePubMedGoogle Scholar
- Zidarn M, Kosnik M, Drinovec I: Anaphylaxis after Hymenoptera sting without detectable specific IgE. Acta Dermatovenerol Alp Panonica Adriat. 2007, 16: 31-3.Google Scholar
- Ruëff F, Przybilla B, Müller U, Mosbech H: The sting challenge test in Hymenoptera venom allergy. Position paper of the Subcommittee on Insect Venom Allergy of the European Academy of Allergology and Clinical Immunology. Allergy. 1996, 51: 216-25.PubMedGoogle Scholar
- Linden van der PW, Hack CE, Kerckhaert JA, Struyvenberg A, Zwan van der JC: Preliminary report: complement activation in wasp-sting anaphylaxis. Lancet. 1990, 336: 904-6. 10.1016/0140-6736(90)92272-J.View ArticlePubMedGoogle Scholar
- Martin TR, Oettgen HC, Martin TR, Wynshaw-Boris A, Deng C, Drazen JM, Leder P: Active anaphylaxis in IgE-deficient mouse. Nature. 1994, 370: 367-10. 10.1038/370367a0.View ArticlePubMedGoogle Scholar
- Korosec P, Erzen R, Silar M, Bajrovic N, Kopac P, Kosnik M: Basophil responsiveness in patients with insect sting allergies and negative venom-specific immunoglobulin E and skin prick test results. Clin Exp Allergy. 2009, 39: 1730-7. 10.1111/j.1365-2222.2009.03347.x.View ArticlePubMedGoogle Scholar
- Ebo DG, Hagendorens MM, Bridts CH, De Clerck LS, Stevens WJ: Hymenoptera venom allergy: taking the sting out of difficult cases. J Investig Allergol Clin Immunol. 2007, 17: 357-360.PubMedGoogle Scholar
- Erdmann SM, Sachs B, Kwiecien R, Moll-Slodowy S, Sauer I, Merk HF: The basophil activation test in wasp venom allergy: sensitivity, specifi city and monitoring specifi c immunotherapy. Allergy. 2004, 59: 1102-9. 10.1111/j.1398-9995.2004.00624.x.View ArticlePubMedGoogle Scholar
- Mosbech H, Mueller U: Side-effects of insect venom immunotherapy: results from an EAACI multicenter study. European Academy of Allergology and Clinical Immunology. Allergy. 2000, 55: 1005-1010. 10.1034/j.1398-9995.2000.00587.x.View ArticlePubMedGoogle Scholar
- Gorska L, Chelminska M, Kuziemski K, Skrzypski M, Niedoszytko M, Damps-Konstanska I, Szymanowska A, Siemiñska A, Wajda B, Drozdowska A, Jutel M, Jassem E: Analysis of safety, risk factors and pretreatment methods during rush hymenoptera venom immunotherapy. Int Arch Allergy Immunol. 2008, 147: 241-5. 10.1159/000142048.View ArticlePubMedGoogle Scholar
- Kosnik M, Silar M, Bajrovic N, Music E, Korosec P: High sensitivity of basophils predicts side-effects in venom immunotherapy. Allergy. 2005, 60: 1401-6. 10.1111/j.1398-9995.2005.00894.x.View ArticlePubMedGoogle Scholar
- Zitnik S, Glavnik V, Avcin T, Accetto M, Toplak N, Silar M, Korosec P: High sensitivity of basophils predict side effect in bee venom immunotherapy in children. Allergy. 2008, 63 (Suppl 88): 642-Google Scholar
- Hunt KJ, Valentine MD, Sobotka AK, Benton AW, Amodio FJ, Lichtenstein LM: A controlled trial of immunotherapy in insect hypersensitivity. N Engl J Med. 1978, 299: 157-61. 10.1056/NEJM197807272990401.View ArticlePubMedGoogle Scholar
- Joanne NG, Elberink O, Monchy JGR, Heide van der S, Guyatt GH, Dubois AEJ: Venom immunotherapy improves health related quality of life in patients allergic to yellow jacket venom. J Allergy Clin Immunol. 2002, 110: 174-82. 10.1067/mai.2002.125827.View ArticleGoogle Scholar
- Roesch A, Boerzsoenyi J, Babilas P, Landthaler M, Szeimies RM: Outcome survey of insect venom allergic patients with venom immunotherapy in a rural population. J Dtsch Dermatol Ges. 2008, 6: 292-7. 10.1111/j.1610-0387.2007.06579.x.View ArticlePubMedGoogle Scholar
- Lerch E, Müller UR: Long-term protection after stopping venom immunotherapy: results of re-stings in 200 patients. J Allergy Clin Immunol. 1998, 101: 606-12. 10.1016/S0091-6749(98)70167-8.View ArticlePubMedGoogle Scholar
- Light WC: Insect sting fatality 9 years after venom treatment. J Allergy Clin Immunol. 2001, 107: 925-10.1067/mai.2001.114985.View ArticlePubMedGoogle Scholar
- Hafner T, DuBuske L, Kosnik M: Long-term efficacy of venom immunotherapy. Ann Allergy Asthma Immunol. 2008, 100: 162-5. 10.1016/S1081-1206(10)60425-5.View ArticlePubMedGoogle Scholar
- Peternelj A, Silar M, Erzen R, Kosnik M, Korosec P: Basophil sensitivity in patients not responding to venom immunotherapy. Int Arch Allergy Immunol. 2008, 146: 248-254. 10.1159/000116361.View ArticlePubMedGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.