Specific immunotherapy using Hymenoptera venom: systematic review

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.

Bee Venom Immunotherapy: Current Status and Future Directions

Bee venom immunotherapy is the main treatment option for bee sting allergy. Its major limitations are the high percentage of allergic side effects and long duration, which are driving the development of novel therapeutic modalities. Three general approaches have been evaluated including the use of hypoallergenic allergen derivatives, adjunctive therapy, and alternative delivery routes. This article reviews preclinical and clinical evidence on the therapeutic potential of these new therapies. Among hypoallergenic derivatives, hybrid allergens showed a markedly reduced IgE reactivity in mouse models. Whether they will offer therapeutic benefit over extract, it is still not known since clinical trials have not been carried out yet. T cell epitope peptides have proven effective in small clinical trials. Major histocompatibility complex class II restriction was circumvented by using long overlapping or promiscuous T cell epitope peptides. However, the T cell-mediated late-phase adverse events have been reported with both short and longer peptides. Application of mimotopes could potentially overcome both T cell- and IgE-mediated adverse events. During this evolution of vaccine, there has been a gain in safety. The efficacy was further improved with the use of Toll-like receptor-activating adjuvants and delivery systems. In murine models, the association of allergen Api m 1 with cytosine-guanosine rich oligonucleotides stimulated strong T-helper type-1 response, whereas its encapsulation into microbubbles protected mice against allergen challenge. An intralymphatic administration of low-dose vaccine has shown the potential to decrease treatment from 5 years to only 12 weeks. Bigger clinical trials are needed to follow up on these results.

Immunophenotypical Characterization of a Brazilian POIS (Post-Orgasmic Illness Syndrome) Patient: Adding More Pieces to Puzzle

Post-orgasmic illness syndrome (POIS) is a rare condition characterized by post-ejaculatory symptoms. Here is reported the first Brazilian POIS patient. Immunological investigation did not confirm the previous hypothesis of a hypersensitivity reaction. Cell immunophenotyping comparing healthy individuals produced evidence of abnormalities not associated to clinical manifestations. The patient was submitted to specific immunotherapy with transient clinical response and was referred to a psychologist but did not demonstrate clinical improvement of symptoms. Therefore, etiology of POIS remains unclear.

Effects of Different Treatment Options on the Prognosis of Wasp Stings

Introduction

Severe wasp sting injuries often threaten patient's life. We compared the effects of three different therapies on the prognosis of wasp stung patients.

Methods

We conducted a randomised single-blind controlled trial. Patients stung by wasp were randomly assigned to one of the three treatment groups: group A received symptomatic treatment; those complicated with acute renal failure and haemolysis also received haemoperfusion combined with haemodialysis; for patients with severe haemolytic anaemia, plasmapheresis were applied; for patients with haemodynamic instability, continuous renal replacement therapy was used. Group B received intravenous methylprednisolone injection, 80 mg/d for continuous 3 days in addition to the symptomatic therapy; for patients with haemolysis, methylprednisolone 0.5 g/d was injected intravenously for 3-5 days. For group C, in addition to all treatments administrated to group B patients, subcutaneous injection of 0.5 ml 0.1% epinephrine was given immediately after admission. Primary endpoint was mortality. Major complications (gastrointestinal haemorrhage, toxic encephalopathy, haemolysis, and acute left ventricular failure) and serum enzyme spectrum elevate (alanine aminotransferase [ALT], creatine kinase [CK] isoenzyme and serum creatinine) were secondary endpoints.

Results

Of 134 patients recruited, 45, 44 and 45 patients were assigned to group A, B or C respectively. Therapy in group C reduced mortality compared with group A and B (respectively 24.4%, 9.09%, 0.00% for group A, B, C respectively; p<0.001); there was no significant effects on major complications among three groups (p >0.1). The incidence of elevated ALT was significantly lower in group B and group C than in group A (p<0.001). The incidence of elevated CK isoenzyme was significantly lower in group C than in group A and group B (p<0.001).

Conclusions

For patients with concurrent organ impairment by wasp sting, early combination of epinephrine and methylprednisolone with supportive treatment with renal replacement therapy can effectively reduce the incidence of organ damage and mortality.

Allergen immunotherapy for insect venom allergy: a systematic review and meta-analysis

BACKGROUND

The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing the EAACI Guidelines on Allergen Immunotherapy (AIT) for the management of insect venom allergy. To inform this process, we sought to assess the effectiveness, cost-effectiveness and safety of AIT in the management of insect venom allergy.

METHODS

We undertook a systematic review, which involved searching 15 international biomedical databases for published and unpublished evidence. Studies were independently screened and critically appraised using established instruments. Data were descriptively summarized and, where possible, meta-analysed.

RESULTS

Our searches identified a total of 16 950 potentially eligible studies; of which, 17 satisfied our inclusion criteria. The available evidence was limited both in volume and in quality, but suggested that venom immunotherapy (VIT) could substantially reduce the risk of subsequent severe systemic sting reactions (OR = 0.08, 95% CI 0.03-0.26); meta-analysis showed that it also improved disease-specific quality of life (risk difference = 1.41, 95% CI 1.04-1.79). Adverse effects were experienced in both the build-up and maintenance phases, but most were mild with no fatalities being reported. The very limited evidence found on modelling cost-effectiveness suggested that VIT was likely to be cost-effective in those at high risk of repeated systemic sting reactions and/or impaired quality of life.

CONCLUSIONS

The limited available evidence suggested that VIT is effective in reducing severe subsequent systemic sting reactions and in improving disease-specific quality of life. VIT proved to be safe and no fatalities were recorded in the studies included in this review. The cost-effectiveness of VIT needs to be established.

Simplification of intradermal skin testing in Hymenoptera venom allergic children

BACKGROUND

The direct comparison between children and adults with Hymenoptera venom anaphylaxis (HVA) has never been extensively reported. Severe HVA with IgE-documented mechanism is the recommendation for venom immunotherapy, regardless of age.

OBJECTIVE

To determine the differences in the basic diagnostic profile between children and adults with severe HVA and its practical implications.

METHODS

We reviewed the medical records of 91 children and 121 adults.

RESULTS

Bee venom allergy was exposure dependent, regardless of age (P < .001). Atopy was more common in children (P = .01), whereas cardiovascular comorbidities were present almost exclusively in adults (P = .001). In the bee venom allergic group, specific IgE levels were significantly higher in children (29.5 kU_A/L; interquartile range, 11.30-66.30 kU_A/L) compared with adults (5.10 kU_A/L; interquartile range, 2.03-8.30 kU_A/L) (P < .001). Specific IgE levels for culprit insect venom were higher in bee venom allergic children compared with the wasp venom allergic children (P < .001). In adults, intradermal tests revealed higher sensitivity, accompanied by larger area of skin reactions, regardless of type of venom. At concentrations lower than 0.1 μg/mL, 16% of wasp venom allergic children and 39% of bee venom allergic children had positive intradermal test results. The median tryptase level was significantly higher in adults than in children for the entire study group (P = .002), as well as in bee (P = .002) and wasp venom allergic groups (P = .049).

CONCLUSION

The basic diagnostic profile in severe HVA reactors is age dependent. Lower skin test reactivity to culprit venom in children may have practical application in starting the intradermal test procedure with higher venom concentrations.

Anaphylaxis: guidelines from the European Academy of Allergy and Clinical Immunology

Anaphylaxis is a clinical emergency, and all healthcare professionals should be familiar with its recognition and acute and ongoing management. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Taskforce on Anaphylaxis. They aim to provide evidence-based recommendations for the recognition, risk factor assessment, and the management of patients who are at risk of, are experiencing, or have experienced anaphylaxis. While the primary audience is allergists, these guidelines are also relevant to all other healthcare professionals. The development of these guidelines has been underpinned by two systematic reviews of the literature, both on the epidemiology and on clinical management of anaphylaxis. Anaphylaxis is a potentially life-threatening condition whose clinical diagnosis is based on recognition of a constellation of presenting features. First-line treatment for anaphylaxis is intramuscular adrenaline. Useful second-line interventions may include removing the trigger where possible, calling for help, correct positioning of the patient, high-flow oxygen, intravenous fluids, inhaled short-acting bronchodilators, and nebulized adrenaline. Discharge arrangements should involve an assessment of the risk of further reactions, a management plan with an anaphylaxis emergency action plan, and, where appropriate, prescribing an adrenaline auto-injector. If an adrenaline auto-injector is prescribed, education on when and how to use the device should be provided. Specialist follow-up is essential to investigate possible triggers, to perform a comprehensive risk assessment, and to prevent future episodes by developing personalized risk reduction strategies including, where possible, commencing allergen immunotherapy. Training for the patient and all caregivers is essential. There are still many gaps in the evidence base for anaphylaxis.

Management of anaphylaxis: a systematic review

To establish the effectiveness of interventions for the acute and long-term management of anaphylaxis, seven databases were searched for systematic reviews, randomized controlled trials, quasi-randomized controlled trials, controlled clinical trials, controlled before-after studies and interrupted time series and - only in relation to adrenaline - case series investigating the effectiveness of interventions in managing anaphylaxis. Fifty-five studies satisfied the inclusion criteria. We found no robust studies investigating the effectiveness of adrenaline (epinephrine), H1-antihistamines, systemic glucocorticosteroids or methylxanthines to manage anaphylaxis. There was evidence regarding the optimum route, site and dose of administration of adrenaline from trials studying people with a history of anaphylaxis. This suggested that administration of intramuscular adrenaline into the middle of vastus lateralis muscle is the optimum treatment. Furthermore, fatality register studies have suggested that a failure or delay in administration of adrenaline may increase the risk of death. The main long-term management interventions studied were anaphylaxis management plans and allergen-specific immunotherapy. Management plans may reduce the risk of further reactions, but these studies were at high risk of bias. Venom immunotherapy may reduce the incidence of systemic reactions in those with a history of venom-triggered anaphylaxis.

Effects of Different Treatment Options on the Prognosis of Wasp Stings

Introduction

Severe wasp sting injuries often threaten patient's life. We compared the effects of three different therapies on the prognosis of wasp stung patients.

Methods

We conducted a randomised single-blind controlled trial. Patients stung by wasp were randomly assigned to one of the three treatment groups: group A received symptomatic treatment; those complicated with acute renal failure and haemolysis also received haemoperfusion combined with haemodialysis; for patients with severe haemolytic anaemia, plasmapheresis were applied; for patients with haemodynamic instability, continuous renal replacement therapy was used. Group B received intravenous methylprednisolone injection, 80 mg/d for continuous 3 days in addition to the symptomatic therapy; for patients with haemolysis, methylprednisolone 0.5 g/d was injected intravenously for 3-5 days. For group C, in addition to all treatments administrated to group B patients, subcutaneous injection of 0.5 ml 0.1% epinephrine was given immediately after admission. Primary endpoint was mortality. Major complications (gastrointestinal haemorrhage, toxic encephalopathy, haemolysis, and acute left ventricular failure) and serum enzyme spectrum elevate (alanine aminotransferase [ALT], creatine kinase [CK] isoenzyme and serum creatinine) were secondary endpoints.

Results

Of 134 patients recruited, 45, 44 and 45 patients were assigned to group A, B or C respectively. Therapy in group C reduced mortality compared with group A and B (respectively 24.4%, 9.09%, 0.00% for group A, B, C respectively; p<0.001); there was no significant effects on major complications among three groups (p >0.1). The incidence of elevated ALT was significantly lower in group B and group C than in group A (p<0.001). The incidence of elevated CK isoenzyme was significantly lower in group C than in group A and group B (p<0.001).

Conclusions

For patients with concurrent organ impairment by wasp sting, early combination of epinephrine and methylprednisolone with supportive treatment with renal replacement therapy can effectively reduce the incidence of organ damage and mortality. (Hong Kong j.emerg.med. 2013;20:270-275)

Recombinant allergen immunotherapy: clinical evidence of efficacy--a review

Recombinant allergens for immunotherapy aim to overcome the problems of natural extracts as they can be produced in unlimited amounts with exact physiochemical and immunological properties. These can be modified to have more favourable characteristics including reduced IgE reactivity or enhanced immunogenicity. Different types of recombinant allergens have been evaluated in clinical phase II and III trials whilst others are currently under development. In this review, we identified double-blind, placebo-controlled randomised clinical trials assessing the efficacy and safety of various recombinant allergen preparations. The majority of studies have up to now focused on cat, grass, birch, ragweed and bee venom allergens. Some studies have shown some of these preparations to be effective and well tolerated. However, there are still outstanding issues regarding optimum doses, minimising side effects and long-term effects.

Clinical effectiveness of hymenoptera venom immunotherapy: a prospective observational multicenter study of the European academy of allergology and clinical immunology interest group on insect venom hypersensitivity

BACKGROUND

Treatment failure during venom immunotherapy (VIT) may be associated with a variety of risk factors.

OBJECTIVE

Our aim was to evaluate the association of baseline serum tryptase concentration (BTC) and of other parameters with the frequency of VIT failure during the maintenance phase.

METHODS

In this observational prospective multicenter study, we followed 357 patients with established honey bee or vespid venom allergy after the maintenance dose of VIT had been reached. In all patients, VIT effectiveness was either verified by sting challenge (n = 154) or patient self-reporting of the outcome of a field sting (n = 203). Data were collected on BTC, age, gender, preventive use of anti-allergic drugs (oral antihistamines and/or corticosteroids) right after a field sting, venom dose, antihypertensive medication, type of venom, side effects during VIT, severity of index sting reaction preceding VIT, and duration of VIT. Relative rates were calculated with generalized additive models.

RESULTS

22 patients (6.2%) developed generalized symptoms during sting challenge or after a field sting. A strong association between the frequency of VIT failure and BTC could be excluded. Due to wide confidence bands, however, weaker effects (odds ratios <3) of BTC were still possible, and were also suggested by a selective analysis of patients who had a sting challenge. The most important factor associated with VIT failure was a honey bee venom allergy. Preventive use of anti-allergic drugs may be associated with a higher protection rate.

INTERPRETATION

It is unlikely that an elevated BTC has a strong negative effect on the rate of treatment failures. The magnitude of the latter, however, may depend on the method of effectiveness assessment. Failure rate is higher in patients suffering from bee venom allergy.

Honeybee venom immunotherapy: certainties and pitfalls

The honeybee is an interesting insect because of the fundamental agricultural role it plays, together with the composition of its venom, which presents new diagnostic and immunotherapeutic challenges. This article examines various aspects of honeybee venom allergy from epidemiology to diagnosis and treatment, with special emphasis on venom immunotherapy (VIT). Honeybee venom allergy represents a risk factor for severe systemic reaction in challenged allergic patients, for the diminished effectiveness of VIT, for more frequent side effects during VIT and relapse after cessation of treatment. Some strategies are available for reducing the risk of honeybee VIT-induced side effects; however, there is considerable room for further improvement in these all-important areas. At the same time, sensitized and allergic beekeepers represent unique populations for epidemiological, venom allergy immunopathogenesis and VIT mechanism studies.

Venom immunotherapy for preventing allergic reactions to insect stings

BACKGROUND

Venom immunotherapy (VIT) is commonly used for preventing further allergic reactions to insect stings in people who have had a sting reaction. The efficacy and safety of this treatment has not previously been assessed by a high-quality systematic review.

OBJECTIVES

To assess the effects of immunotherapy using extracted insect venom for preventing further allergic reactions to insect stings in people who have had an allergic reaction to a sting.

SEARCH METHODS

We searched the following databases up to February 2012: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 1946), EMBASE (from 1974), PsycINFO (from 1806), AMED (from 1985), LILACS (from 1982), the Armed Forces Pest Management Board Literature Retrieval System, and OpenGrey. There were no language or publication status restrictions to our searches. We searched trials databases, abstracts from recent European and North American allergy meetings, and the references of identified review articles in order to identify further relevant trials.

SELECTION CRITERIA

Randomised controlled trials of venom immunotherapy using standardised venom extract in insect sting allergy.

DATA COLLECTION AND ANALYSIS

Two authors independently undertook study selection, data extraction, and assessment of risk of bias. We identified adverse events from included controlled trials and from a separate analysis of observational studies identified as part of a National Institute for Health and Clinical Excellence Health Technology Assessment.

MAIN RESULTS

We identified 6 randomised controlled trials and 1 quasi-randomised controlled trial for inclusion in the review; the total number of participants was 392. The trials had some risk of bias because five of the trials did not blind outcome assessors to treatment allocation. The interventions included ant, bee, and wasp immunotherapy in children or adults with previous systemic or large local reactions to a sting, using sublingual (one trial) or subcutaneous (six trials) VIT. We found that VIT is effective for preventing systemic allergic reaction to an insect sting, which was our primary outcome measure. This applies whether the sting occurs accidentally or is given intentionally as part of a trial procedure.In the trials, 3/113 (2.7%) participants treated with VIT had a subsequent systemic allergic reaction to a sting, compared with 37/93 (39.8%) untreated participants (risk ratio [RR] 0.10, 95% confidence interval [CI] 0.03 to 0.28). The efficacy of VIT was similar across studies; we were unable to identify a patient group or mode of treatment with different efficacy, although these analyses were limited by small numbers. We were unable to confirm whether VIT prevents fatal reactions to insect stings, because of the rarity of this outcome.Venom immunotherapy was also effective for preventing large local reactions to a sting (5 studies; 112 follow-up stings; RR 0.41, 95% CI 0.24 to 0.69) and for improving quality of life (mean difference [MD] in favour of VIT 1.21 points on a 7-point scale, 95% CI 0.75 to 1.67).We found a significant risk of systemic adverse reaction to VIT treatment: 6 trials reported this outcome, in which 14 of 150 (9.3%) participants treated with VIT and 1 of 135 (0.7%) participants treated with placebo or no treatment suffered a systemic reaction to treatment (RR 8.16, 95% CI 1.53 to 43.46; 2 studies contributed to the effect estimate). Our analysis of 11 observational studies found systemic adverse reactions occurred in 131/921 (14.2%) participants treated with bee venom VIT and 8/289 (2.8%) treated with wasp venom VIT.

AUTHORS' CONCLUSIONS

We found venom immunotherapy using extracted insect venom to be an effective therapy for preventing further allergic reactions to insect stings, which can improve quality of life. The treatment carries a small but significant risk of systemic adverse reaction.

Clinical and immunological changes of immunotherapy in patients with atopic dermatitis: randomized controlled trial

Background. Immunotherapy has proven to be an useful tool in the management of allergic respiratory diseases; however, little has been studied in atopic dermatitis. Objective. To evaluate the clinical and immunological impact of immunotherapy with mites allergen extracts in atopic dermatitis. Methods. Patients with atopic dermatitis were assigned with computer-generated randomization to either of the following groups: (a) controls received only topical treatment with steroids and/or tacrolimus and (b) actively treated patients received topical treatment plus immunotherapy. Levels of serum total IgE, mites-specific IgE and IgG4 were assessed at study start and after one year of immunotherapy. Results. 31 patients in the active group and 29 in the control group completed the study. Symptoms and medication scores were significantly reduced in the active group after six months. Three patients in the control group showed new sensitizations to mites, while 3 patients in the active group showed neosensitization to shrimp with negative oral food challenge. We observed significant increase of mites-specific IgG4 levels in active group. Conclusion. Specific allergen immunotherapy induced a tolerogenic IgG4 response to mite allergens associated with favorable clinical effects in atopic dermatitis patients.

Immunotherapy: The meta-analyses. What have we Learned?

Meta-analysis is a powerful tool for evaluating the efficacy of a therapeutic intervention, and has clearly demonstrated that specific allergen immunotherapy (SIT) is effective for treating allergic rhinitis and asthma. Future research needs to focus on specifying the most effective forms of SIT for specific populations and allergens, using validated clinical outcomes, studying long-term outcomes (particularly the potential disease-modifying effect of immunotherapy), and assessing outcomes regarding health economics. The safety profile of SIT should be evaluated using international guidelines and terminology, and needs to include high-quality surveillance data.

[Evidence-based practices published in Brazil: identification and analysis of their types and methodological approches]

This is an integrative review of Brazilian studies on evidence-based practices (EBP) in health, published in ISI/JCR journals in the last 10 years. The aim was to identify the specialty areas that most accomplished these studies, their foci and methodological approaches. Based on inclusion criteria, 144 studies were selected. The results indicate that most EBP studies addressed childhood and adolescence, infectious diseases, psychiatrics/mental health and surgery. The predominant foci were prevention, treatment/rehabilitation, diagnosis and assessment. The most used methods were systematic review with or without meta-analysis, protocol review or synthesis of available evidence studies, and integrative review. A strong multiprofessional expansion of EBP is found in Brazil, contributing to the search for more selective practices by collecting, recognizing and critically analyzing the produced knowledge. The study also contributes to the analysis itself of ways to do research and new research possibilities.