New directions in diagnostic evaluation of insect allergy

Clinical Practice Guideline: Immunotherapy for Inhalant Allergy

OBJECTIVE

Allergen immunotherapy (AIT) is the therapeutic exposure to an allergen or allergens selected by clinical assessment and allergy testing to decrease allergic symptoms and induce immunologic tolerance. Inhalant AIT is administered to millions of patients for allergic rhinitis (AR) and allergic asthma (AA) and is most commonly delivered as subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT). Despite its widespread use, there is variability in the initiation and delivery of safe and effective immunotherapy, and there are opportunities for evidence-based recommendations for improved patient care.

PURPOSE

The purpose of this clinical practice guideline (CPG) is to identify quality improvement opportunities and provide clinicians trustworthy, evidence-based recommendations regarding the management of inhaled allergies with immunotherapy. Specific goals of the guideline are to optimize patient care, promote safe and effective therapy, reduce unjustified variations in care, and reduce the risk of harm. The target patients for the guideline are any individuals aged 5 years and older with AR, with or without AA, who are either candidates for immunotherapy or treated with immunotherapy for their inhalant allergies. The target audience is all clinicians involved in the administration of immunotherapy. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the guideline development group (GDG). It is not intended to be a comprehensive, general guide regarding the management of inhaled allergies with immunotherapy. The statements in this guideline are not intended to limit or restrict care provided by clinicians based on their experience and assessment of individual patients.

ACTION STATEMENTS

The GDG made a strong recommendation that (Key Action Statement [KAS] 10) the clinician performing allergy skin testing or administering AIT must be able to diagnose and manage anaphylaxis. The GDG made recommendations for the following KASs: (KAS 1) Clinicians should offer or refer to a clinician who can offer immunotherapy for patients with AR with or without AA if their patients' symptoms are inadequately controlled with medical therapy, allergen avoidance, or both, or have a preference for immunomodulation. (KAS 2A) Clinicians should not initiate AIT for patients who are pregnant, have uncontrolled asthma, or are unable to tolerate injectable epinephrine. (KAS 3) Clinicians should evaluate the patient or refer the patient to a clinician who can evaluate for signs and symptoms of asthma before initiating AIT and for signs and symptoms of uncontrolled asthma before administering subsequent AIT. (KAS 4) Clinicians should educate patients who are immunotherapy candidates regarding the differences between SCIT and SLIT (aqueous and tablet) including risks, benefits, convenience, and costs. (KAS 5) Clinicians should educate patients about the potential benefits of AIT in (1) preventing new allergen sensitizations, (2) reducing the risk of developing AA, and (3) altering the natural history of the disease with continued benefit after discontinuation of therapy. (KAS 6) Clinicians who administer SLIT to patients with seasonal AR should offer pre- and co-seasonal immunotherapy. (KAS 7) Clinicians prescribing AIT should limit treatment to only those clinically relevant allergens that correlate with the patient's history and are confirmed by testing. (KAS 9) Clinicians administering AIT should continue escalation or maintenance dosing when patients have local reactions (LRs) to AIT. (KAS 11) Clinicians should avoid repeat allergy testing as an assessment of the efficacy of ongoing AIT unless there is a change in environmental exposures or a loss of control of symptoms. (KAS 12) For patients who are experiencing symptomatic control from AIT, clinicians should treat for a minimum duration of 3 years, with ongoing treatment duration based on patient response to treatment. The GDG offered the following KASs as options: (KAS 2B) Clinicians may choose not to initiate AIT for patients who use concomitant beta-blockers, have a history of anaphylaxis, have systemic immunosuppression, or have eosinophilic esophagitis (SLIT only). (KAS 8) Clinicians may treat polysensitized patients with a limited number of allergens.

Wasp-stung rat model translationally expresses the coagulopathy manifestations of human wasp patients

Two over 80 wasp stings male victims appeared severe abnormal coagulation were consecutively examined by thromboelastography (TEG) guided with heparinase during hospitalization. However, the cause of coagulopathy remains unsolved. Rats were applied to establish a wasp-stung animal model highly resembled the manifestations of wasp-stung patients. According body surface area conversion, Sprague-Dawley rats were stung based on wasp sting numbers (0, 4, 8, 12 stings; n = 6 each) with various exposure times (0, 1, 3, 6 h) to determine the simulation of coagulopathy. The blood R, K values, and angle degree of wasp-stung rats were measured by TEG. The TEG profiles of stung rats were found to be concomitant with that of wasp-stung patients. Data showed that the endogenous heparinization of rats was time-dependent. Compared to the TEG profile of eight stings given rat, the coagulation time of 2 mm clot formation at 3 h (R value) was longer than that at 0 h. The coagulation time was prolonged with increasing sting numbers when compared to the various stings at 1, 3, and 6 h exposed. Interestingly, there was observed the peak coagulation at 3 h of eight stings. The Ck-standard and Ck-heparinase at 3 h after 8 stings given were R: 9.6-4.4 min; K: 3.8-1.8 min; angle degree: 49.8-68.0, respectively. The original data of R, K values and angle degree in two wasp-stung victims were 11.7-13.6 min, 4.3-5.5 min, and 41.2-32.8° in CK-standard, respectively; whereas those of the CK-heparinase groups were 5.6-6.7 min, 2.4-2.5 min, and 59.5-58.8°, correspondingly. Conclusively, this massive wasp-stung animal model can be applied to the investigations of pathogenesis and provides a clinical strategy or guideline for clinical intervention.

Ant sting-induced whole-body pustules in an inebriated male: A case report

BACKGROUND

Many ant species can harm humans; however, only a few cause life-threatening allergic reactions. Normally, reactions caused by ants occur in patients who come into contact with ant venom. Venom contains various biologically active peptides and protein components, of which acids and alkaloids tend to cause anaphylaxis. Ant venom can cause both immediate and delayed reactions. The main histopathological changes observed in ant hypersensitivity are eosinophil recruitment and Th2 cytokine production.

CASE SUMMARY

A 70-year-old man was bitten by a large number of ants when he was in a drunken stupor and was hospitalized at a local hospital. Five days later, because of severe symptoms, the patient was transferred to our hospital for treatment. Numerous pustules were observed interspersed throughout the body, with itching and pain reported. He had experienced fever, vomiting, hematochezia, mania, soliloquy, sleep disturbances, and elevated levels of myocardial enzymes since the onset of illness. The patient had a history of hypertension for more than 1 year, and his blood pressure was within the normal range after hypotensive drug treatment. He had no other relevant medical history. Based on the clinical history of an ant bite and its clinical manifestations, the patient was diagnosed with an ant venom allergy. The patient was treated with 60 mg methylprednisolone for 2 d, 40 mg methylprednisolone for 3 d, and 20 mg methylprednisolone for 2 d. Oral antihistamines and diazepam were administered for 12 d and 8 d, respectively. Cold compresses were used to treat the swelling during the process. After 12 d of treatment, most pustules became crusts, whereas some had faded away. No symptoms of pain, itching, or psychological disturbances were reported during the follow-up visits within 6 mo.

CONCLUSION

This case report emphasizes the dangers of ant stings.

Global View on Ant Venom Allergy: from Allergenic Components to Clinical Management

Hymenoptera venom allergy is characterised by systemic anaphylactic reactions that occur in response to stings from members of the Hymenoptera order. Stinging by social Hymenoptera such as ants, honeybees, and vespids is one of the 3 major causes of anaphylaxis; along with food and drug exposure, it accounts for up to 43% of anaphylaxis cases and 20% of anaphylaxis-related fatalities. Despite their recognition as being of considerable public health significance, stinging ant venoms are relatively unexplored in comparison to other animal venoms and may be overlooked as a cause of venom allergy. Indeed, the venoms of stinging ants may be the most common cause of anaphylaxis in ant endemic areas. A better understanding of the natural history of venom allergy caused by stinging ants, their venom components, and the management of ant venom allergy is therefore required. This article provides a global view on allergic reactions to the venoms of stinging ants and the contemporary approach to diagnose and manage ant venom allergy.

Sex Differences in Adults with Insect Venom Allergy regarding Psychological Distress, Attitudes toward the Emergency Medication, and Factual Knowledge about the Disease

BACKGROUND

Hymenoptera venom allergy (HVA) has a prevalence of 3% in adults. Although patients have no ongoing symptoms, they often suffer from an impairment of their psychological well-being and quality of life.

OBJECTIVE

The aim of this study was to analyze sex-specific differences regarding the psychological burden caused by this allergy and handling of the emergency medication.

METHOD

Study participants filled out a questionnaire including sociodemographic and disease-specific characteristics, the Hospital Anxiety and Depression Score (HADS), and theoretical knowledge about the emergency medication set (EMS). Additionally, an objective structured clinical examination was used to assess practical knowledge and handling of the EMS.

RESULTS

Fifty-six patients were included (55.4% females). Female patients showed higher subjective anxiety levels due to HVA compared to men (mean 7.2 vs. 4.6, p = 0.0003). Furthermore, the HADS revealed that women had a significant higher anxiety level, especially after Mueller grade I-II anaphylactic reactions (mean 6.3 vs. 2.8, p = 0.0134). This was associated with a higher theoretical but not practical knowledge about their disease. On the other hand, males were less inclined to carry the emergency medication "always" or "almost always" (56 vs. 87.1%, p = 0.0015) but showed higher self-assurance in using it (mean 7.3 vs. 6.1, p = 0.0446).

CONCLUSIONS

This clinical study provides evidence for sex differences in coping with HVA. The results suggest that females should be monitored more closely for allergy-associated anxiety symptoms, while men need more encouragement to carry the emergency medication.

Current Advances in Immunological Studies on the Vespidae Venom Antigen 5: Therapeutic and Prophylaxis to Hypersensitivity Responses

Although systemic reactions caused by allergenic proteins present in venoms affect a small part of the world population, Hymenoptera stings are among the main causes of immediate hypersensitivity responses, with risk of anaphylactic shock. In the attempt to obtain therapeutic treatments and prophylaxis to hypersensitivity responses, interest in the molecular characterization of these allergens has grown in the scientific community due to the promising results obtained in immunological and clinical studies. The present review provides an update on the knowledge regarding the immune response and the therapeutic potential of Antigen 5 derived from Hymenoptera venom. The results confirm that the identification and topology of epitopes, associated with molecular regions that interact with antibodies, are crucial to the improvement of hypersensitivity diagnostic methods.

The culprit insect but not severity of allergic reactions to bee and wasp venom can be determined by molecular diagnosis

Background

Allergy to bee and wasp venom can lead to life-threatening systemic reactions. The identification of the culprit species is important for allergen-specific immunotherapy.

Objectives

To determine a panel of recombinant bee and wasp allergens which is suitable for the identification of bee or wasp as culprit allergen sources and to search for molecular surrogates of clinical severity of sting reactions.

Methods

Sera from eighty-seven patients with a detailed documentation of their severity of sting reaction (Mueller grade) and who had been subjected to titrated skin testing with bee and wasp venom were analyzed for bee and wasp-specific IgE levels by ImmunoCAP^TM. IgE-reactivity testing was performed using a comprehensive panel of recombinant bee and wasp venom allergens (rApi m 1, 2, 3, 4, 5 and 10; rVes v 1 and 5) by ISAC chip technology, ImmunoCAP and ELISA. IgG₄ antibodies to rApi m 1 and rVes v 5 were determined by ELISA and IgE/IgG₄ ratios were calculated. Results from skin testing, IgE serology and IgE/IgG₄ ratios were compared with severity of sting reactions.

Results

The panel of rApi m 1, rApi m 10, rVes v 1 and rVes v 5 allowed identification of the culprit venom in all but two of the 87 patients with good agreement to skin testing. Severities of sting reactions were not associated with results obtained by skin testing, venom-specific IgE levels or molecular diagnosis. Severe sting reactions were observed in patients showing < 1 ISU and < 2kU_A/L of IgE to Api m 1 and/or Ves v 5.

Conclusion

We identified a minimal panel of recombinant bee and wasp allergens for molecular diagnosis which may permit identification of bee and/or wasp as culprit insect in venom-sensitized subjects. The severity of sting reactions was not associated with parameters obtained by molecular diagnosis.

Allergenic extracts to diagnose and treat sensitivity to insect venoms and inhaled allergens

OBJECTIVE

To review allergenic extracts used to diagnose or treat insect allergies, including how the extracts are manufactured and their measurements of potency or concentration.

DATA SOURCES

Peer-reviewed articles derived from searching PubMed (National Center for Biotechnology Information) about insect allergies and extract preparation. Encyclopedia of Life (http://www.eol.org/) and http://allergome.org/ were also referenced for background information on insects and associated allergens.

STUDY SELECTIONS

Search terms used for the PubMed searches included insect allergens and allergies, Apidae, Vespidae, fire ants, cockroach allergies, insect allergen extract preparation, and standardization.

RESULTS

Humans may be sensitized to insect allergens by inhalation or through stings. Cockroaches and moths are predominantly responsible for inhalation insect allergy and are a major indoor allergen in urban settings. Bees, fire ants, and wasps are responsible for sting allergy. In the United States, there are multiple insect allergen products commercially available that are regulated by the US Food and Drug Administration. Of those extracts, honeybee venom and insect venom proteins are standardized with measurements of potency. The remaining insect allergen extracts are nonstandardized products that do not have potency measurements.

CONCLUSION

Sensitization to inhalational and stinging insect allergens is reported worldwide. Crude insect allergen extracts are used for diagnosis and specific immunotherapy. A variety of source materials are used by different manufacturers to prepare these extracts, which may result in qualitative differences that are not reflected in measurements of potency or protein concentration.

[Dengue with unusual clinical features in an infant: Case report]

The state of Yucatan, in Mexico, is an endemic area for dengue. During 2015, there was an unpredicted increase in the number of expected cases of dengue fever.

OBJECTIVE

To describe and analyse the clinical presentation, progress, and management of a case of dengue infection with non-specific clinical manifestations in an infant which resulted in a dengue shock syndrome.

CASE REPORT

One month old infant admitted to hospital with a generalised rash and a history of being bitten by an insect. He was diagnosed with anaphylaxis based on clinical manifestations and anamnesis. While in hospital, he developed hypotension, tachycardia, anaemia, and respiratory distress. He was transferred to the intensive care unit, but died on the fifth day. He tested positive to dengue virus in the PCR test and for IgG antibodies using Elisa. The basic cause of death was dengue shock syndrome.

CONCLUSIONS

Dengue fever in young infant infections may be afebrile, so it is important to suspect them appropriately in the presence of a generalised rash, tachycardia, and hypotension, in order to avoid the deadly consequences of dengue shock.

Improved recombinant Api m 1- and Ves v 5-based IgE testing to dissect bee and yellow jacket allergy and their correlation with the severity of the sting reaction

BACKGROUND

No study has assessed the diagnostic sensitivity of rApi m 1 and rVes v 5 on Immulite testing system.

OBJECTIVE

To compare the diagnostic sensitivity of commercially available venom recombinant allergens between the currently available immunoassays [ImmunoCAP (CAP) and Immulite (LITE)] and establish their correlation with the severity of the sting reaction.

METHODS

This study evaluated 95 bee venom and 110 yellow jacket venom-allergic subjects. We measured the levels of sIgE to rApi m 1, rVes v 5 (LITE and CAP), rApi m 2 (LITE), rVes v 1 (CAP) and total IgE (CAP). Forty-nine healthy subjects served as controls.

RESULTS

The diagnostic sensitivity of rApi m 1 and rVes v 5 was significantly higher with the LITE than with the CAP system (71% vs. 88% and 82% vs. 93%). The specificity of both assays for both allergens was between 94% and 98%. Twenty-nine patients that tested negative for rApi m 1 or rVes v 5 with CAP were positive with LITE, but none of the patients that tested negative with LITE were positive with CAP. The positive values of rApi m 1 and rVes v 5 were on average 2.7 and 2.3 times higher, with the LITE than with the CAP system. The combination of rApi m 1 and rApi m 2 (LITE) and the combination of rVes v 5 (LITE) and rVes v 1 (CAP) almost matched the sensitivity of native venoms (95% and 97%, respectively), whereas the diagnostic sensitivity of the combination of rVes v 5 and rVes v 1 (CAP) did not reach the sensitivity of rVes v 5 (LITE) alone (90% vs. 93%). IgE levels to venom recombinants and total IgE did not correlate with the severity of sting reaction.

CONCLUSIONS & CLINICAL RELEVANCE

The use of rApi m 1 and rVes v 5 with the LITE system significantly enhanced diagnostic utility of venom recombinants and should improve the dissection of bee and yellow jacket venom allergy.

EAACI Molecular Allergology User's Guide

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.

2015 update of the evidence base: World Allergy Organization anaphylaxis guidelines

The World Allergy Organization (WAO) Guidelines for the assessment and management of anaphylaxis provide a unique global perspective on this increasingly common, potentially life-threatening disease. Recommendations made in the original WAO Anaphylaxis Guidelines remain clinically valid and relevant, and are a widely accessed and frequently cited resource. In this 2015 update of the evidence supporting recommendations in the Guidelines, new information based on anaphylaxis publications from January 2014 through mid- 2015 is summarized. Advances in epidemiology, diagnosis, and management in healthcare and community settings are highlighted. Additionally, new information about patient factors that increase the risk of severe and/or fatal anaphylaxis and patient co-factors that amplify anaphylactic episodes is presented and new information about anaphylaxis triggers and confirmation of triggers to facilitate specific trigger avoidance and immunomodulation is reviewed. The update includes tables summarizing important advances in anaphylaxis research.

Anaphylaxis to insect venom allergens: role of molecular diagnostics

Anaphylaxis due to Hymenoptera stings is one of the most severe consequences of IgE-mediated hypersensitivity reactions. Although allergic reactions to Hymenoptera stings are often considered as a general model for the underlying principles of allergic disease, diagnostic tests are still hampered by a lack of specificity and venom immunotherapy by severe side effects and incomplete protection. In recent years, the knowledge about the molecular composition of Hymenoptera venoms has significantly increased and more and more recombinant venom allergens with advanced characteristics have become available for diagnostic measurement of specific IgE in venom-allergic patients. These recombinant venom allergens offer several promising possibilities for an improved diagnostic algorithm. Reviewed here are the current status, recent developments, and future perspectives of molecular diagnostics of venom allergy. Already to date, it is foreseeable that component-resolution already has now or will in the future have the potential to discriminate between clinically significant and irrelevant sensitization, to increase the specificity and sensitivity of diagnostics, to monitor immunotherapeutic intervention, and to contribute to the understanding of the immunological mechanisms elicited by insect venoms.

Stinging insect allergy: current perspectives on venom immunotherapy

Systemic allergic reactions to insect stings affect up to 5% of the population during their lifetime, and up to 32% of beekeepers. Such reactions can be fatal, albeit very rarely, and fear of a further systemic reaction (SR) can lead to significant anxiety and quality of life impairment. A recent Cochrane systematic review confirmed that venom immunotherapy (VIT) is an effective treatment for people who have had a systemic allergic reaction to an insect sting. VIT reduces risk of a further SR (relative risk 0.10, 95% confidence interval 0.03-0.28), but VIT also reduces risk of a future large local reaction, and significantly improves disease-specific quality of life. However, health economic analysis showed that VIT is generally not cost effective for preventing future SRs; most people are stung infrequently, most SRs resolve without long-term consequences, and a fatal outcome is extremely rare. VIT only becomes cost effective if one is stung frequently (eg, beekeepers) or if quality of life improvement is considered. Thus, for most people with insect sting allergy, anxiety and quality of life impairment should be the overriding consideration when making treatment decisions, highlighting the importance of a patient-centered approach. Areas which need to be explored in future research include efforts to improve the safety and convenience of VIT such as the use of sublingual immunotherapy; quality of life effects of venom allergy in children and adolescents as well as their parents; and the optimal duration of treatment.

Specific immunotherapy and biological treatments for occupational allergy

PURPOSE OF REVIEW

Occupational allergy represents a substantial health, social, and financial burden for the society. Its management is a complex task that, in selected cases, may also include allergen-specific immunotherapy. The purpose of this article is to review clinical data on allergen immunotherapy and biological treatments applied to occupational allergy in 2013.

RECENT FINDINGS

Immunotherapy in occupational allergic diseases has been scarcely used, and only for a few sensitizers, such as latex, flour, and Hymenoptera venom, partly due to the lack of standardized extracts. The recent use of the molecular diagnosis can improve the indication and selection of suitable allergens for preparing new standardized and powerful extracts for immunotherapy. Some recent reports suggest a beneficial role of treatment with omalizumab in workers with occupational asthma who continue to be exposed to the causal agent.

SUMMARY

Although scarce, available data suggest that immunotherapy and biological treatments may allow allergic workers to continue their work activity, but further studies are needed to standardize extracts and to evaluate the cost-effectiveness of these treatments, when exposure at the workplace cannot be avoided.

A Pitfall to Avoid When Using an Allergen Microarray: The Incidental Detection of IgE to Unexpected Allergens

The introduction of new laboratory techniques to detect specific IgE antibodies against single allergen molecules rather than whole extracts represents a significant advance in allergy diagnostics. The advantages of such component-resolved diagnosis can be summarized as follows: (1) the ability to identify the truly responsible allergens in polysensitized patients, whether they be genuine (causing specific sensitization to their corresponding allergen source) or primary (the original sensitizing molecule); (2) distinguishing these allergens from simply cross-reactive components; (3) improving the appropriateness of the prescribed specific immunotherapy; and (4) identifying a risk profile for food allergens. Component-resolved diagnosis is performed using either a singleplex (1 assay per sample) platform or a multiplex (multiple assays per sample) platform. Using an immuno solid-phase allergen chip microarray that falls into the latter category--it currently tests sensitivity to 112 allergens--may lead to a pitfall: detecting IgE to unexpected allergens, such as Hymenoptera venom. In fact, testing insect venom sensitivity in individuals with no history of reactions to stings is contrary to current guidelines and presents the physician with the dilemma of how to manage this information; moreover, this may become a legal issue. Based on what is currently known about venom allergy, it remains likely that a positive sensitization test result will have no clinical significance, but the possibility of reacting to a future sting cannot be completely ruled out. Because this problem has not been previously encountered using the more common allergy tests, no indications are currently available on how to effectively manage these cases.