Natural history of Hymenoptera venom sensitivity in adults

Risk Factors Associated with Severe Systemic Allergic Reaction after Wasp Sting in Subjects with a History of European Hornet Sting Allergy

Aim

To make the treatment approach in patients suffering a European hornet sting allergy reaction more personalized, preparing them also for possible future risks.

Methods

In Slovenia an extended retrospective observational cohort epidemiological study about the natural history of Hymenoptera venom sensitivity is in progress. The study is based on data from the healthcare records of the University Clinic Golnik (UCG) and data collected by a questionnaire sent to patients from May 2019 to April 2021. For a pilot study, we selected patients who were referred to UCG because of an allergic reaction to European hornet sting and had been re-stung later by a wasp (n=68). The association between severe systemic allergic reactions (SSAR) after wasp sting and potential risk factors in subjects with a history of hornet sting allergy was assessed univariately using the likelihood ratio test.

Results

Among 68 European hornet allergic patients 27 reacted with an SSAR and 41 reacted with a mild SAR. Among 27 patients with SSAR, 4 reacted with an SSAR also to a subsequent wasp sting. Among 41 patients with a mild European hornet sting SAR nobody reacted with an SSAR to a subsequent wasp sting. The association between the severity of the wasp SAR reaction in European hornet allergic patients was statistically significant (p=0.022).

Conclusion

Our results suggest that patients with severe European hornet SAR should be considered for wasp venom immunotherapy or prophylactic prescription of epinephrine auto-injector as they are at risk for an SSAR also after wasp string.

Clonal mast cell disorders and hereditary α-tryptasemia as risk factors for anaphylaxis

The association between Hymenoptera venom-triggered anaphylaxis (HVA) and clonal mast cell-related disorders (cMCD) has been known for decades. However, recent breakthroughs in peripheral blood screening for KIT p.D816V missense variant have revealed the true extent of this clinical association whilst adding to our understanding of the underlying aetiology. Thus, recent large studies highlighted the presence of KIT p.D816V among 18.2% and 23% of patients with severe Hymenoptera venom-triggered anaphylaxis. A significant proportion of those patients have normal serum basal tryptase (BST) levels, with no cutaneous findings such as urticaria pigmentosa or other systemic findings such as organomegaly that would have suggested the presence of cMCD. These findings of an increased prevalence suggest that the impact of cMCD on anaphylaxis could be clinically underestimated and that the leading question for clinicians could be changed from 'how many patients with cMCD have anaphylaxis?' to 'how many patients with anaphylaxis have cMCD?'. The discovery of hereditary α-tryptasemia (HαT)-a genetic trait caused by an increased copy number of the Tryptase Alpha/Beta 1 (TPSAB1) gene-, first described in 2016, is now known to underlie the majority of cases of elevated BST outside of cMCD and chronic kidney disease. HαT is the first common heritable genetic modifier of anaphylaxis described, and it is associated with increased risk for severe HVA (relative risk = 2.0), idiopathic anaphylaxis, and an increased prevalence of anaphylaxis in patients with cMCD, possibly due to the unique activity profile of α/β -tryptase heterotetramers that may potentiate immediate hypersensitivity reaction severity. Our narrative review aims to highlight recent research to have increased our understanding of cMCD and HαT, through recent lessons learned from studying their association with HVA. Additionally, we examined the studies of mast cell-related disorders in food and drug allergy in an effort to determine whether one should also consider cMCD and/or HαT in cases of severe anaphylaxis triggered by food or drugs.

Intracutaneous Skin Tests and Serum IgE Levels Cannot Predict the Grade of Anaphylaxis in Patients with Insect Venom Allergies

Background

Allergies against Hymenoptera venoms are a major cause of severe anaphylaxis. Risk assessment for subjects with suspected allergy is difficult because there are currently no biomarkers that predict the likelihood of high-grade anaphylaxis other than several associated comorbidities.

Objective

We investigated the relationship between the severity of anaphylaxis and the results of intracutaneous skin tests (ICTs) together with serum levels of tryptase, total IgE, and venom-specific IgE, IgG, and IgG4.

Methods

We performed a retrospective evaluation of 194 patients who presented to a single medical center with allergies to bee venoms (Apis mellifera, Bombus spp.; n=24, 12.4%), vespid venoms (Vespula spp., Vespa spp., Polistes spp.; n=169, 87.1%), or both (n=1, 0.5%).

Results

Index bee stings occurred earlier in the year than vespid stings, although the latter were reported more frequently overall. On average, subjects who previously experienced grade IV anaphylaxis required higher dosages of venom to yield positive ICTs than those who exhibited lower grade responses. Patients diagnosed with grade IV anaphylaxis exhibited significantly lower levels of venom-specific IgE and IgG and trended toward elevated levels of tryptase. No significant differences in average levels of venom-specific IgG4 and total IgE were observed.

Conclusion

Our findings reveal that intracutaneous skin testing and levels of venom-specific IgE do not predict the degree of anaphylaxis that develops in patients with venom allergy. Furthermore, the month of the index sting is not a reliable means to differentiate bee from vespid stings in patients presenting with an uncertain history.

Natural History of the Hymenoptera Venom Sensitivity Reactions in Adults: Study Design

Background: Allergic reactions to Hymenoptera stings can have varying levels of severity, according to the Müller grading system. Methods: By an epidemiological concept, this is a retrospective cohort study. The observed cohort was represented by patients referred to the University Clinic Golnik due to Hymenoptera allergic reaction in the period from 1997 to 2015. From the immunological database of the University Clinic Golnik, we obtained laboratory data (sIgE, skin tests and basophil activation test). The clinical characteristics of patients were obtained from BIRPIS. With the help of a questionnaire, which was sent to each patient in the period from May 2019 to April 2021, we obtained epidemiological data. For the assessment of the association between the severity of allergic reaction for the observed outcome, the severity of the first allergic reaction after Hymenoptera sting was used. Other variables were grouped according to risk factors. Discussion: We will identify the risk factors that could play an important role in a severe systemic reaction: the aetiology of the Hymenoptera sting, sex, age, history and severity of previous systemic reactions, being re-stung in an interval of two months, the frequency of re-stings, atopy, genetic predisposition, preventive medication use, other medication use, beekeeping or living next to beehives and why immunotherapy was not taken. Laboratory data will also be analysed to determine if there is any association with laboratory tests and the severity of the allergic reactions after Hymenoptera stings. Conclusions: Several new approaches are introduced in the study design. The most important is that the protocol covers epidemiological data gained from the questionnaire, as well as clinical data gained from the Immunological database and BIRPIS database. We expect to obtain significant results that will explain the risk factors for the natural history of Hymenoptera sting allergic reactions and will help allergologists, as well as general doctors, when facing those patients allergic to Hymenoptera venom without immunotherapy.

Serum Allergen-Specific IgE among Pediatric Patients with Primary Immunodeficiency

Background: Allergy is a clinical condition that reflects a deviated function of the immune system. The purpose of this study was to evaluate serum allergen-specific IgE (sIgE) along with clinical manifestations of allergy in patients with diagnosed primary immunodeficiency (PID). Methods: 72 patients, aged 1−17 years, diagnosed with PID and hospitalized between July 2020 and February 2021 were included in the study. Blood samples were obtained by venipuncture. sIgE (30 allergens), blood eosinophil count, as well as total IgE and IgG were measured and assessed in relation to a detailed medical examination. Results: Serum sIgE was detected in the blood of 50% of the patients in the study group, which significantly correlated (p < 0.0001) with clinical symptoms of allergy. During the period of the study, 61.1% of the patients showed symptoms of allergy, with 77.27% of them having tested positive for sIgE. The total IgE level was elevated in 18.06% of the patients and correlated with clinical symptoms of allergy (p = 0.004). An elevated total IgE level was not observed in children receiving immunoglobulin replacement therapy. Conclusion: The study showed that serum sIgE and total IgE together might be a plausible diagnostic tool for PID patients. However, for patients receiving immunoglobulin replacement therapy, the assessment of total IgE is not useful.

Venom Immunotherapy and Aeroallergen Immunotherapy: How Do Their Outcomes Differ?

Allergen immunotherapy (AIT) and venom immunotherapy (VIT) are meant to work on the causes of allergies, respectively, to respiratory allergens and Hymenoptera venom, inducing tolerance to the allergens and modifying the natural history of allergy. Both types of immunotherapies have evidence of efficacy, but actually they present wide differences in both effectiveness and safety. Indeed, as far as the effectiveness of VIT is concerned, if the protection against fatal reactions to stings is considered as the primary objective, more than 40 years of clinical practice demonstrate complete success. The clinical success of AIT is measurable on the basis of reduction or disappearance of allergic symptoms. The difference between the two treatments is even higher as regards safety: AIT has been concerned in the past by a series of fatal reactions caused, which underwent a progressive decrease when it was understood that they were related to the presence of uncontrolled asthma. However, fatal reactions related to failure to recognize the presence of risk factors or administration errors are still reported. Similarly to what has been observed for efficacy, VIT has never been affected by fatal reactions to the administration of venom, and the most important risk of anaphylaxis, which is the concomitance of mastocytosis, is now identified by measuring its marker serum tryptase. To date, mechanisms of hypersensitivity reactions that differentiate respiratory allergy from Hymenoptera venom allergy have not been successfully demonstrated. We have examined the past and present literature in order to propose reasonable hypotheses about the mechanisms actually involved.

Combining Discordant Serum IgE and Skin Testing Improves Diagnostic and Therapeutic Accuracy for Hymenoptera Venom Hypersensitivity Immunotherapy

BACKGROUND

Diagnosis of patients with hymenoptera venom hypersensitivity consists of elucidating clinical symptoms suggestive of systemic reaction (SR) and then confirmation of sensitization via intradermal skin testing (IDST) first and serum IgE assays such as ImmunoCAP (ICAP) as a complementary modality of diagnosis.

OBJECTIVE

Determine the concordance between ICAP and IDST in patients with a clinical history suggestive of hymenoptera venom SR. Determine whether venom immunotherapy would change on the basis of IDST versus ICAP results.

METHODS

A prospective diagnostic study was designed to test the concordance between IDST and ICAP venom testing in the diagnosis of hymenoptera venom hypersensitivity. This study entailed testing both IDST and ICAP for 5 hymenoptera venoms (honey bee, wasp, yellow jacket, yellow hornet, and white-faced hornet) in both a case group with SR to hymenoptera venom (N = 70) and a control group without SR (N = 51).

RESULTS

Significant discordance was observed between positive IDST and ICAP results for any of the 5 hymenoptera venoms (McNemar test, P = .001). In the case group, there was significant discordance for wasp (P < .0001), yellow jacket (P = .002), and white-faced hornet (P = .02). More than 47% of the case patients would have different venom immunotherapy prescriptions if ICAP and IDST had been performed during initial diagnosis versus IDST alone.

CONCLUSIONS

Our study shows significant discordance between IDST and ICAP; however, they are complementary. On the basis of our data, we propose ICAP testing first followed by IDST for ICAP-negative venoms as an alternative and efficient diagnostic strategy.

Immunogenicity of Milk Protein-Containing Hydrophilic Gel Patch for Epicutaneous Immunotherapy for Milk Allergy

PURPOSE

Epicutaneous immunotherapy (EPIT) involving the skin's immune system is easy to use, painless and has a low risk of systemic side effects; it can be applied to food allergies that have a high morbidity rate in children. In this study, we evaluated the safety and efficacy of hydrophilic gel patch (HG) for EPIT.

METHODS

Milk protein concentrate (MPC)-containing HG was applied to the skin that maintained a barrier function or formed puncture holes with microneedle, and MPC-specific antibodies were measured. The clinical study was conducted involving patients with severe milk allergy.

RESULTS

No specific immune response was induced when immunizing to intact skin, and antibody production was observed by forming puncture holes. It was suggested that MPC contained in HG has immunogenicity and a very small amount of MPC was delivered to intact skin. In the clinical study, the symptom induction threshold increased in four of eight subjects, allowing them to consume milk and switch to oral immunotherapy. Although local skin reactions and temporary elevation of specific IgE antibodies were observed, no systemic side effects appeared throughout the study.

CONCLUSIONS

EPIT using HG is a safe method to enable oral administration even in patients with severe milk allergies.

Approach to Patients with Stinging Insect Allergy

Stinging insect allergy is uncommon but can be life threatening. Diagnosis requires clinical history and confirmative skin or blood testing by an allergist. Baseline serum tryptase level can be used to stratify risk. Treatment is supportive for all reactions except for anaphylaxis, which is treated with intramuscular epinephrine, recumbent posture, and adjunct measures such as IV fluids, and oxygen. Venom immunotherapy is most effective for long-term management in patients with a history of anaphylaxis. Venom immunotherapy rapidly reduces the risk of sting anaphylaxis by up to 98% and maintenance treatment can be stopped after 5 years in most cases.

A longitudinal study of hymenoptera stings in preschool children

BACKGROUND

Insect venom is the second most common cause of anaphylaxis outside of medical encounters. Stings cause over 20% of all anaphylactic deaths and 7% of anaphylaxis in children. To date, there have been no longitudinal studies of insect sting events or allergy in preschool children.

METHODS

A prospective longitudinal nested observational study in the BASELINE Birth Cohort Study (n = 2137). Sting-related questions were asked at 6 and 12 months and 2 and 5 years. Skin prick testing (SPT) was performed at 2 and 5 years. SpIgE testing was performed on selected cases at 2 years.

RESULTS

Seventy-seven children (6.8%) were stung by the age of 2. Of these, 25 (32.5%) reported adverse reactions (four systemic). Eleven (0.9%) had positive SPT at 2 years (eight bee, two wasp, one both). Four stung children had positive SPT. Two (one stung, one never stung) had positive spIgE to a venom component at 2 years. A total of 268 children (21.9%) were stung by 5 years, 144 (52.1%) reporting local reactions and none systemic. Four children (0.4%) had positive SPT at 5 years: one bee and three wasp. Of the 11 SPT-positive children at 2 years, none were still positive at 5 years.

CONCLUSION

This is the first longitudinal study of the natural history of hymenoptera stings and allergy in preschool children. Hymenoptera venom allergy is less common in this cohort than in adults. Systemic reactions were not medically documented in this population, in keeping with previous literature. This study confirms the poor correlation of IgE sensitization to venom with sting allergy and does not support the common parental request to screen children for sting allergy.

A 13-year real-life study on efficacy, safety and biological effects of Vespula venom immunotherapy

Background

Hymenoptera venom immunotherapy (VIT) is a clinically effective treatment. However, little is known about its long-term clinical efficacy and biological effects. Several mechanisms have been proposed to account for VIT efficacy, including reduction of specific IgE and induction of allergen-specific IgG₄, but the overall picture remains elusive. We investigated Vespula VIT clinical efficacy up to 8 years after discontinuation and the kinetics of Vespula-specific IgE and IgG₄. Out of 686 consecutive patients we retrospectively selected and analysed a series of 23 patients with Vespula allergy that underwent a 5-year IT course, followed by a prolonged follow-up.

Methods

Clinical efficacy of VIT was assessed as number and severity of reactions to Vespula re-stinging events. The presence of Vespula-specific IgE and IgG₄ was also monitored over time.

Results

During the VIT treatment, patients were protected, reporting no reactions or mild reactions in occasion of re-stinging events. This protection was entirely maintained during the follow-up, up to 8 years. Skin reactivity (reflecting mast cell-bound Vespula-specific IgE) and circulating Vespula-specific IgE levels declined substantially during VIT. Notably, this reduction was maintained over time during the follow-up. Moreover, all the patients were analysed for IgG₄. A robust induction of Vespula-specific IgG₄ was observed during the VIT course, with a substantial decline during the follow-up.

Conclusions

We conclude that Vespula VIT is a clinically effective treatment, which induces long-term protection after discontinuation. The reduction of specific IgE, assessed by skin tests and RAST, closely matches the VIT- induced protection, while the IgG₄ induction seems not to be associated with VIT clinical efficacy in the long term.

Electronic supplementary material

The online version of this article (10.1186/s12948-017-0079-y) contains supplementary material, which is available to authorized users.

Diagnostics in Hymenoptera venom allergy: current concepts and developments with special focus on molecular allergy diagnostics

Background

The high rate of asymptomatic sensitization to Hymenoptera venom, difficulty in correctly identifying Hymenoptera and loss of sensitization over time make an accurate diagnosis of Hymenoptera venom allergy challenging. Although routine diagnostic tests encompassing skin tests and the detection of venom-specific IgE antibodies with whole venom preparations are reliable, they offer insufficient precision in the case of double sensitized patients or in those with a history of sting anaphylaxis, in whom sensitization cannot be proven or only to the presumably wrong venom.

Methods

Systematic literature research and review of current concepts of diagnostic testing in Hymenoptera venom allergy.

Results and discussion

Improvements in diagnostic accuracy over recent years have mainly been due to the increasing use of molecular allergy diagnostics. Detection of specific IgE antibodies to marker and cross-reactive venom allergens improves the discrimination between genuine sensitization and cross-reactivity, and this provides a better rationale for prescribing venom immunotherapy. The basophil activation test has also increased diagnostic accuracy by reducing the number of Hymenoptera venom sensitizations overlooked with routine tests. This paper reviews current concepts of diagnostic testing in Hymenoptera venom allergy and suggests fields for further development.

Insect Sting Reactions and Specific IgE to Venom and Major Allergens in a General Population

BACKGROUND

Insect sting reactions are frequently reported, but population studies documenting the frequency and the relation to IgE-sensitization and serum tryptase are scarce.

METHODS

Questionnaire data and results from measurements of specific IgE against venom, major allergens and cross-reacting carbohydrate determinants (CCDs) were collected from 2,090 adult participants in a cross-sectional survey.

RESULTS

13% of the population reported symptoms of sting reactions and about half were systemic in nature. In all, 15% were sensitized to venom but only 31% of these had reacted to stings and only 38% of those with reactions had IgE to venom. In addition, 12% with IgE to venom were double-sensitized (DS), i.e. to both bee and wasp venom. Among DS IgE to major venom allergens, rApi m 1, rVes v 1 and rVes v 5 were negative and of no help in 31%, but 59% could be identified as likely sensitized to bee or wasp. IgE to CCDs occurred in only 0.7%, but 80% of these were DS. Finally, 36% with IgE to CCDs had had symptoms, mostly local. Serum tryptase was not associated with a history of sting reactions.

CONCLUSIONS

In a temperate climate, self-reported insect sting reactions and sensitization to venom are frequent, but in most cases, these are not seen in the same individual. In DS individuals, measurements of IgE to major allergens can be helpful in some but not all cases and additional analyses are needed. IgE to CCDs may have some clinical relevance.

Determinants of venom-specific IgE antibody concentration during long-term wasp venom immunotherapy

Background

Venom immunotherapy (VIT) is an effective treatment for subjects with systemic allergic reactions (SR) to Hymenoptera stings, however there are few studies concerning the relevance of the venom specific IgE changes to decide about VIT cessation. We assessed IgE changes during a 5-year VIT, in patients stung and protected within the first 3 years (SP 0–3) or in the last 2 years (SP 3–5), and in patients not stung (NoS), to evaluate possible correlations between IgE changes and clinical protection.

Methods

Yellow jacket venom (YJV)-allergic patients who completed 5 years of VIT were retrospectively evaluated. Baseline IgE levels and after the 3rd and the 5th year of VIT were determined; all patients were asked about field stings and SRs.

Results

A total of 232 YJV-allergic patients were included and divided into the following groups: 84 NoS, 72 SP 0–3 and 76 SP 3–5. IgE levels decreased during VIT compared to baseline values (χ² = 346.029, p < 0.001). Recent vespid stings accounted for significantly higher IgE levels despite clinical protection. IgE levels after 5 years of VIT correlated significantly with Mueller grade (F = 2.778, p = 0.012) and age (F = 6.672, p = 0.002). During follow-up from 1 to 10 years after VIT discontinuation, 35.2 % of the contacted patients reported at least one field sting without SR.

Conclusions

The yellow jacket-VIT temporal stopping criterion of 5 years duration did not result in undetectable IgE levels, despite a long-lasting protection. A mean IgE decrease from 58 to 70 % was observed, and it was less marked in elderly patients or in subjects with higher Mueller grade SR.

New directions in diagnostic evaluation of insect allergy

PURPOSE OF REVIEW

Diagnosis of insect sting allergy and prediction of risk of sting anaphylaxis are often difficult because tests for venom-specific IgE antibodies have a limited positive predictive value and do not reliably predict the severity of sting reactions.

RECENT FINDINGS

Component-resolved diagnosis using recombinant venom allergens has shown promise in improving the specificity of diagnostic testing for insect sting allergy. Basophil activation tests have been explored as more sensitive assays for identification of patients with insect allergy and for prediction of clinical outcomes. Measurement of mast cell mediators reflects the underlying risk for more severe reactions and limited clinical response to treatment.

SUMMARY

Measurement of IgE to recombinant venom allergens can distinguish cross-sensitization from dual sensitization to honeybee and vespid venoms, thus helping to limit venom immunotherapy to a single venom instead of multiple venoms in many patients. Basophil activation tests can detect venom allergy in patients who show no detectable venom-specific IgE in standard diagnostic tests and can predict increased risk of systemic reactions to venom immunotherapy, and to stings during and after stopping venom immunotherapy. The risk of severe or fatal anaphylaxis to stings can also be predicted by measurement of baseline serum tryptase or other mast cell mediators.

Venom immunotherapy: an updated review

Venom immunotherapy (VIT) is the most effective form of specific immunotherapy to date. Hitherto, several relevant queries remain unanswered, namely optimal doses, duration, and means of assessment. Important progress has been lately made in terms of diagnosis by means of component-resolved diagnosis. Moreover, basophil activation test results in patients with negative serum immunoglobulin E (IgE) and skin prick test confer this technique a promising future, although these outcomes shall be considered with caution. This review aims to unravel the important advances made on diagnosis, management, and prognosis and also focuses on several undetermined aspects of VIT.

Single venom-based immunotherapy effectively protects patients with double positive tests to honey bee and Vespula venom

Background

Referring to individuals with reactivity to honey bee and Vespula venom in diagnostic tests, the umbrella terms “double sensitization” or “double positivity” cover patients with true clinical double allergy and those allergic to a single venom with asymptomatic sensitization to the other. There is no international consensus on whether immunotherapy regimens should generally include both venoms in double sensitized patients.

Objective

We investigated the long-term outcome of single venom-based immunotherapy with regard to potential risk factors for treatment failure and specifically compared the risk of relapse in mono sensitized and double sensitized patients.

Methods

Re-sting data were obtained from 635 patients who had completed at least 3 years of immunotherapy between 1988 and 2008. The adequate venom for immunotherapy was selected using an algorithm based on clinical details and the results of diagnostic tests.

Results

Of 635 patients, 351 (55.3%) were double sensitized to both venoms. The overall re-exposure rate to Hymenoptera stings during and after immunotherapy was 62.4%; the relapse rate was 7.1% (6.0% in mono sensitized, 7.8% in double sensitized patients). Recurring anaphylaxis was statistically less severe than the index sting reaction (P = 0.004). Double sensitization was not significantly related to relapsing anaphylaxis (P = 0.56), but there was a tendency towards an increased risk of relapse in a subgroup of patients with equal reactivity to both venoms in diagnostic tests (P = 0.15).

Conclusions

Single venom-based immunotherapy over 3 to 5 years effectively and long-lastingly protects the vast majority of both mono sensitized and double sensitized Hymenoptera venom allergic patients. Double venom immunotherapy is indicated in clinically double allergic patients reporting systemic reactions to stings of both Hymenoptera and in those with equal reactivity to both venoms in diagnostic tests who have not reliably identified the culprit stinging insect.

Hymenoptera Venom Immunotherapy: Tolerance and Efficacy of an Ultrarush Protocol versus a Rush and a Slow Conventional Protocol

Background and Objective. Various venom immunotherapy (VIT) protocols are available for Hymenoptera allergy. Although adverse reactions (ADRs) to VIT are widely reported, controlled trials are still needed. We conducted a randomized prospective study to evaluate ADRs and the efficacy of three VIT regimens. Methods. 76 patients with Hymenoptera allergy, aged 16-76 years, were randomized to receive an ultrarush protocol (group A: 27 patients), a rush protocol (group B: 25), or a slow protocol (group C: 24). Aqueous venom extract was used in incremental phase and an adsorbed depot in maintenance phase. ADRs and accidental Hymenoptera stings during VIT were used to evaluate efficacy. Results. During incremental treatment, ADRs occurred in 1.99%, 3.7%, and 3.9% of patients in groups A, B, and C, and in 0.99%, 1.46%, and 2.7%, respectively, during maintenance. ADRs were significantly fewer in group A (incremental + maintenance phase) than in group C (1.29% versus 3.2%; P = 0.013). Reactions to accidental Hymenoptera stings did not differ among groups (1.1%, 1.2%, and 1.1%). Conclusion. Ultrarush was as effective as the rush and slow protocols and was associated with a low incidence of reactions to stings. This study indicates that ultrarush VIT is a valid therapeutic option for Hymenoptera allergy.

Risk of squamous cell carcinoma of the skin in relation to IgE: a nested case-control study

BACKGROUND

Individuals diagnosed with nonmelanoma skin cancer have a high risk of developing a second skin cancer diagnosis. We assessed whether a marker of immune function related to atopic allergy, IgE, was associated with diagnosis of subsequent squamous cell carcinoma (SCC) of the skin in patients with a previous skin cancer enrolled in a skin cancer prevention trial.

METHODS

One hundred twelve individuals who developed an SCC (cases) were compared with 227 controls who did not develop SCC over the same followup period, matched on age, sex, and study center. Total, respiratory, and food-specific IgE were measured in the baseline or year one (prior to diagnosis) sera samples for each subject.

RESULTS

IgE levels were higher in cases with SCC than controls (comparing the highest quartile with the lowest, OR(total IgE) = 1.44; 95% CI: 0.73-2.85; OR(respiratory IgE) = 2.43; 95% CI: 1.16-5.06; OR(food IgE) = 2.53; 95% CI: 1.19-5.35). The association between respiratory IgE and subsequent skin cancer was strongest among individuals with a tendency to sunburn (OR(respiratory IgE) = 3.82; 95% CI: 1.05-13.88) compared with those with a tendency to tan (OR(respiratory IgE) = 0.95; 95% CI: 0.20-4.76). Among 25 subjects with repeat IgE measurements taken over several years, IgE levels were remarkably stable (interclass coefficient = 0.90 for total IgE).

CONCLUSION

These results indicate that allergy or allergy-associated IgE may be indicative of an immune phenotype that enhances risk of SCC, possibly via immune-associate inflammatory mediators.

IMPACT

Our results indicate that controlling allergy and IgE levels may be a new avenue of skin cancer prevention in susceptible populations, and implicate immune mechanisms in skin carcinogenesis.

Mechanisms of immunotherapy to wasp and bee venom

Hymenoptera venoms are important allergens that can elicit both local and systemic allergic reactions, including life-threatening anaphylaxis. Venom immunotherapy (VIT) remains the most effective treatment, reducing the risk of systemic reactions in individuals with Hymenoptera venom allergy. VIT can restore normal immunity against venom allergens and provide patients with a lifetime of tolerance to venoms. During VIT, peripheral tolerance is induced by the generation of allergen-specific regulatory T (Treg) cells, which suppress proliferative and cytokine responses against the venom allergens. Treg cells are characterized by IL-10 secretion that directly or indirectly influence effector cells of allergic inflammation, such as mast cells, basophils and eosinophils. Treg cells also have influence on B cells, suppressing IgE production and inducing the production of blocking type IgG4 antibodies against venom allergens. An accumulating body of evidence suggests that Treg cells may affect allergen sensitization and methods for enhancing this cell population may eventually improve the efficacy of VIT. In this article, immune mechanisms enrolled in bee and wasp VIT are reviewed.

Hymenoptera venom immunotherapy

Subcutaneous venom immunotherapy is the only effective treatment for patients who experience severe hymenoptera sting-induced allergic reactions, and the treatment also improves health-related quality of life. This article examines advances in various areas of this treatment, which include the immunological mechanisms of early and long-term efficacy, indications and contraindications, selection of venom, treatment protocols, duration, risk factors for systemic reactions in untreated and treated patients as well as for relapse following cessation of treatment. Current and future strategies for improving safety and efficacy are also examined. However, although progress in the past few years has been fruitful, much remains to be accomplished.

Stinging insect hypersensitivity: a practice parameter update 2011

These parameters were developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma and Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Stinging insect hypersensitivity: a practice parameter update II." Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or the ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma and Immunology. This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. These parameters are not designed for use by pharmaceutical companies in drug promotion. The Joint Task Force understands that the cost of diagnostic tests and therapeutic agents is an important concern that may appropriately influence the work-up and treatment chosen for a given patient. The Joint Task Force recognizes that the emphasis of our primary recommendations regarding a medication may vary, for example, depending on third party payer issues and product patent expiration dates. However, since a given test or agent's cost is so widely variable, and there is a paucity of pharmacoeconomic data, the Joint Task Force generally does not consider cost when formulating Practice Parameter recommendations. In extraordinary circumstances, when the cost benefit of an intervention is prohibitive as supported by pharmacoeconomic data, commentary may be provided.

Gene expression analysis predicts insect venom anaphylaxis in indolent systemic mastocytosis

BACKGROUND

Anaphylaxis to insect venom (Hymenoptera) is most severe in patients with mastocytosis and may even lead to death. However, not all patients with mastocytosis suffer from anaphylaxis. The aim of the study was to analyze differences in gene expression between patients with indolent systemic mastocytosis (ISM) and a history of insect venom anaphylaxis (IVA) compared to those patients without a history of anaphylaxis, and to determine the predictive use of gene expression profiling.

METHODS

Whole-genome gene expression analysis was performed in peripheral blood cells.

RESULTS

Twenty-two adults with ISM were included: 12 with a history of IVA and 10 without a history of anaphylaxis of any kind. Significant differences in single gene expression corrected for multiple testing were found for 104 transcripts (P < 0.05). Gene ontology analysis revealed that the differentially expressed genes were involved in pathways responsible for the development of cancer and focal and cell adhesion suggesting that the expression of genes related to the differentiation state of cells is higher in patients with a history of anaphylaxis. Based on the gene expression profiles, a naïve Bayes prediction model was built identifying patients with IVA.

CONCLUSIONS

In ISM, gene expression profiles are different between patients with a history of IVA and those without. These findings might reflect a more pronounced mast cells dysfunction in patients without a history of anaphylaxis. Gene expression profiling might be a useful tool to predict the risk of anaphylaxis on insect venom in patients with ISM. Prospective studies are needed to substantiate any conclusions.

Multiple epinephrine doses for stinging insect hypersensitivity reactions treated in the emergency department

BACKGROUND

Data are sparse on epinephrine treatment for stinging insect hypersensitivity (SIH) reactions.

OBJECTIVE

To establish the frequency of receiving more than 1 dose of epinephrine in patients presenting to the emergency department (ED) with SIH reactions.

METHODS

We performed a medical record review of all 153 patients with SIH reactions presenting to 3 EDs in Boston, Massachusetts, between January 1, 2001, and December 31, 2006. Patients were identified by International Classification of Diseases, Ninth Revision (ICD-9) codes (989.5, 995.0, and 995.3). We focused on clinical presentations and treatments, including epinephrine treatments given before and during the ED visit.

RESULTS

The cohort was 54% male, with a median age of 33 years. Bees were the most frequently reported triggering insect (74%). A total of 59% of patients experienced large local reactions, whereas 36% had systemic reactions (10% cutaneous systemic and 26% anaphylaxis). The remaining 5% presented with normal local reactions to insect stings. Among patients with systemic reactions, 82% were stung within 3 hours of arrival at the ED. Most (60%) received treatments before arrival at the ED, including 26% who received epinephrine. While in the ED, these patients received antihistamines (76%), systemic corticosteroids (55%), and epinephrine (9%). Overall, 35% of patients with systemic reactions received epinephrine, and among this subset, 16% received more than 1 dose. Most patients with systemic reactions (67%) were discharged to home. At ED discharge, 68% received a prescription for self-injectable epinephrine, but only 11% had documentation of referral to an allergist.

CONCLUSIONS

Among patients with systemic SIH reactions who received epinephrine, 16% received a second dose. Physicians should consider prescribing 2 doses of self-injectable epinephrine for patients at risk for systemic SIH reactions.

The diagnosis and management of anaphylaxis practice parameter: 2010 update

These parameters were developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma and Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "The Diagnosis and Management of Anaphylaxis Practice Parameter: 2010 Update." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, or the Joint Council of Allergy, Asthma and Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Anaphylaxis: Recent advances in assessment and treatment

The incidence rate of anaphylaxis is increasing, particularly during the first 2 decades of life. Common triggers include foods, medications, and insect stings. Clinical diagnosis is based on a meticulous history of an exposure or event preceding characteristic symptoms and signs, sometimes but not always supported by a laboratory test such as an elevated serum total tryptase level. Physician-initiated investigation of patients with anaphylaxis whose symptoms and signs are atypical sometimes leads to important insights into previously unrecognized triggers and mechanisms. In idiopathic anaphylaxis, in which no trigger can be confirmed by means of skin testing or measurement of specific IgE, the possibility of mastocytosis or a clonal mast cell disorder must be considered in addition to the possibility of a previously unrecognized trigger. Long-term risk reduction in patients with anaphylaxis focuses on optimal management of relevant comorbidities such as asthma and other respiratory diseases, cardiovascular disease, and mastocytosis or a clonal mast cell disorder; avoidance of the relevant confirmed allergen trigger; and relevant immunomodulation such as medication desensitization, venom immunotherapy, and possibly in the future, immunotherapy with food. Emergency preparedness for recurrence of anaphylaxis in community settings includes having epinephrine (adrenaline) autoinjectors available, knowing when and how to use them, and having a written, personalized anaphylaxis emergency action plan and up-to-date medical identification. Randomized controlled trials of the pharmacologic interventions used in an acute anaphylaxis episode are needed.

Mastocytosis and insect venom allergy: diagnosis, safety and efficacy of venom immunotherapy

The most important causative factor for anaphylaxis in mastocytosis are insect stings. The purpose of this review is to analyse the available data concerning prevalence, diagnosis, safety and effectiveness of venom immunotherapy (VIT) in mastocytosis patients. If data were unclear, authors were contacted personally for further information. Quality of evidence (A: high, B: moderate, C: low and D: very low) and strength of recommendation (strong 1 and weak 2) concerning VIT in mastocytosis patients are assessed according to the Grading of Recommendations Assessment, Development and Evaluation and are marked in square brackets. Results of VIT were described in 117 patients to date. The mean rate of side-effects during treatment in studies published so far is 23.9% (7.6% requiring adrenaline) with an overall protection rate of 72%. Based on the review we conclude that (1) mastocytosis patients have a high risk of severe sting reactions in particular to yellow jacket, (2) VIT could be suggested [2] in mastocytosis, (3) probably should be done life long [2], (4) VIT in mastocytosis is accompanied by a higher frequency of side-effects, so (5) special precautions should be taken into account notably during the built up phase of the therapy [2], (6) VIT is able to reduce systemic reactions, but to a lesser extent compared to the general insect venom allergic population [2], so (7) patients should be warned that the efficacy of VIT might be less than optimal and they should continue carrying two adrenaline auto injectors [2].