Wasp venom from Vespa magnifica acts as a neuroprotective agent to alleviate neuronal damage after stroke in rats

CONTEXT

Acute ischaemic stroke (AIS) is a major cause of disability and death, which is a serious threat to human health and life. Wasp venom extracted from Vespa magnifica Smith (Vespidae) could treat major neurological disorders.

OBJECTIVE

This study investigated the effects of wasp venom on AIS in rats.

MATERIAL AND METHODS

We used a transient middle cerebral artery occlusion (MCAO) model in Sprague-Dawley rats (260-280 g, n = 8-15) with a sham operation group being treated as negative control. MCAO rats were treated with wasp venom (0.05, 0.2 and 0.6 mg/kg, i.p.) using intraperitoneal injection. After treatment 48 h, behavioural tests, cortical blood flow (CBF), TTC staining, H&E staining, Nissl staining, TUNEL assay, immunohistochemistry (IHC) and ELISA were employed to investigate neuroprotective effects of wasp venom.

RESULTS

Compared with the MCAO group, wasp venom (0.6 mg/kg) improved neurological impairment, accelerated CBF recovery (205.6 ± 52.92 versus 216.7 ± 34.56), reduced infarct volume (337.1 ± 113.2 versus 140.7 ± 98.03) as well as BBB permeability as evidenced by changes in claudin-5 and AQP4. In addition, function recovery of stroke by wasp venom treatment was associated with a decrease in TNF-α, IL-1β, IL-6 and inhibition activated microglia as well as apoptosis. Simultaneously, the wasp venom regulated the angiogenesis factors VEGF and b-FGF in the brain.

CONCLUSIONS

Wasp venom exhibited a potential neuroprotective effect for AIS. In the future, we will focus on determining whether the observed actions were due to a single compound or the interaction of multiple components of the venom.

Involvement of the gabaergic, serotonergic and glucocorticoid mechanism in the anxiolytic-like effect of mastoparan-L

Mastoparan-L (mast-L) is a cell-penetrating tetradecapeptide and stimulator of monoamine exocytosis. In the present study, we evaluated the anxiolytic-like effect of mast-L. Preliminary pharmacological tests were conducted to determine the most appropriate route of administration, extrapolate dose and detect potential toxic effects of this peptide. Oral and intracerebroventricular administration of mast-L (0.1, 0.3 or 0.9 mg.kg^-1), diazepam (1 or 5 mg.kg^-1), buspirone (10 mg.kg^-1) or vehicle 10 mL.kg^-1 was carried out prior to the exposure of mice to the anxiety models: open field, light-dark box and elevated plus-maze. To characterize the mechanism underlying the antianxiety-like effect of mast-L, pharmacological antagonism, blood plasma analysis, molecular docking, and receptor binding assays were performed. The absence of a neurotoxic sign, animal's death as well as lack of significant changes in the relative organ weight, hematological and biochemical parameters suggest that mast-L is relatively safe. The anxiolytic-like effect of mast-L was attenuated by flumazenil (antagonist of benzodiazepine binding site) and WAY100635 (selective antagonist of 5-HT_1A receptors) pretreatments. Mast-L reduced plasma corticosterone and lowered the scoring function at GABA_A -18.48 kcal/mol (Ki = 155 nM), 5-HT_1A -22.39 kcal/mol (Ki = 130 nM), corticotropin-releasing factor receptor subtype 1 (CRF1) -11.95 kcal/mol (Ki = 299 nM) and glucocorticoid receptors (GR) -14.69 kcal/mol (Ki = 3552 nM). These data fit the binding affinity (Ki) and demonstrate the involvement of gabaergic, serotonergic and glucocorticoid mechanisms in the anxiolytic-like property of mast-L.

MRGPR-mediated activation of local mast cells clears cutaneous bacterial infection and protects against reinfection

Mast cells (MCs) are strategically distributed at barrier sites and prestore various immunocyte-recruiting cytokines, making them ideal targets for selective activation to treat peripheral infections. Here, we report that topical treatment with mastoparan, a peptide MC activator (MCA), enhances clearance of Staphylococcus aureus from infected mouse skins and accelerates healing of dermonecrotic lesions. Mastoparan functions by activating connective tissue MCs (CTMCs) via the MRGPRX2 (Mas-related G protein-coupled receptor member X2) receptor. Peripheral CTMC activation, in turn, enhances recruitment of bacteria-clearing neutrophils and wound-healing CD301b⁺ dendritic cells. Consistent with MCs playing a master coordinating role, MC activation also augmented migration of various antigen-presenting dendritic cells to draining lymph nodes, leading to stronger protection against a second infection challenge. MCAs therefore orchestrate both the innate and adaptive immune arms, which could potentially be applied to combat peripheral infections by a broad range of pathogens.

Which immunotherapy product is better for patients allergic to Polistes venom? A laboratory and clinical study

BACKGROUND

Venom immunotherapy (VIT) is highly effective in preventing allergic reactions to insect stings, but the appropriate venom must be used to achieve clinical protection. In patients with multiple positive results to venoms, molecular allergy diagnostics or CAP-inhibition may identify the causative venom. Concerning allergy to venom from Polistes spp. it has been proposed that only the European species P. dominulus should be used for VIT. However, this recommendation is not present in any international guideline. Using both laboratory and clinical data, we aimed to evaluate the reliability of this proposal.

METHODS

We performed an in vitro study using CAP-inhibition to determine sensitization of 19 patients allergic to Polistes venom. The clinical study included 191 patients with positive tests to Polistes treated with VIT, 102 were treated with P. dominulus and 89 were treated with a mix of American Polistes (mAP).

RESULTS

The difference in % of inhibition was significant concerning inhibition of P. dominulus sIgE by P. dominulus venom (79.8%) compared with inhibition by mAP venom (64.2%) and not significant concerning the inhibition of mAP sIgE by P. dominulus venom (80.1%) and by mAP venom (73.6%). Instead, the clinical protection from stings was not statistically different between the two kinds of venom.

CONCLUSION

The data from CAP inhibition would suggest that the choice of either P. dominulus venom or mAP venom for VIT is appropriate in patients with CAP inhibition higher than 70%, but the clinical data show the same odds of protection from stings using for VIT P. dominulus or mAP venom.

Safety of Ultrarush Venom Immunotherapy: Comparison Between Children and Adults

BACKGROUND

The ultrarush protocol is an attractive approach in the buildup phase of venom immunotherapy (VIT-UR). However, the degree of risk of VIT-UR in children remains unknown. The objective of this study was to compare the safety of VIT-UR in children and adults.

METHODS

We performed a study based on prospectively gathered medical records of children and adults with hymenoptera venom allergy treated with VIT-UR in 3 allergy centers in Poland.

RESULTS

The study population comprised 134 children (mean [SD] age, 12.6 [3.7] years; males, 70.1%) and 207 adults (mean age, 42.4 [14.0] years; males, 47.8%). The number of children in the subgroups of bee venom (BV) allergy and wasp venom (WV) allergy were comparable, although sensitization to WV was more predominant in the adult group (70.1%). Skin reactivity to both venoms was more common in children than in adults (P < .001); however, children had higher concentrations of total IgE and specific IgE to BV (both P < .001). Systemic allergic reactions (VIT-SARs) occurred in 6.2% of the patients (3.7% in children and 7.7% in adults; nonsignificant). In adults, SARs occurred more frequently in patients treated with BV than WV extracts (21.4% vs 2.6%; P < .001). The same pattern was observed in children (7.2% vs 0%; P = .058). However, VIT-SARs to BV were less frequent in children than in adults (P = .034). Similarly, no significant relationship was noted between children and adults receiving WV VIT (2.6% vs 0%; nonsignificant). The severity of VIT-SAR did not differ between children and adults.

CONCLUSIONS

VIT-UR is safer in children. Age below 18 is not a risk factor for VIT-SARs.

Rush immunotherapy for wasp venom allergy seems safe and effective in patients with mastocytosis

BACKGROUND

Patients with mastocytosis and wasp venom allergy (WA) may benefit from venom immunotherapy (VIT). However, fatal insect sting reactions have been described in mastocytosis patients despite previous immunotherapy. We investigated the safety and efficacy of (rush) VIT in patients with mastocytosis and WA.

OBJECTIVE

To investigate the safety and efficacy of (rush) VIT in patients with mastocytosis and WA.

METHODS

We describe nine patients with cutaneous mastocytosis and WA who received VIT. Cutaneous mastocytosis was confirmed by histopathology and systemic mastocytosis was diagnosed according to World Health Organization criteria. VIT was given according to a rush protocol. Given the difference in safety and efficacy of VIT in patients with WA and honeybee venom allergy, we reviewed the literature for VIT with the focus on WA patients with mastocytosis and addressed the difference between patients with cutaneous versus systemic mastocytosis.

RESULTS

Nine patients had WA and mastocytosis, of whom six had cutaneous mastocytosis, two combined cutaneous and systemic mastocytosis and one systemic mastocytosis. All patients received rush IT with wasp venom. Most patients had only mild local side effects, with no systemic side effects during the course of VIT. One patient had a systemic reaction upon injection on one occasion, during the updosing phase, with dyspnoea and hypotension, but responded well to treatment. Immunotherapy was continued after temporary dose adjustment without problems. Two patients with a previous anaphylactic reaction were re-stung, without any systemic effects.

CONCLUSIONS

VIT is safe in cutaneous mastocytosis patients with WA, while caution has to be made in case of systemic mastocytosis. VIT was effective in the patients who were re-stung.

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.

[Influence of venom immunotherapy on anxiety level of being re-stung]

Hymenoptera venom allergy is related to higher risk of potential life -threatening anaphylactic reactions, which leads to anxiety and decreased quality of life.

AIM

The aim of this paper was: 1) estimation of fear level of being re-stung among venom allergy adults treated with venom specific immunotherapy (VIT)--before and during treatment; 2) estimation of expectation of outcome of VIT as compared to level of anxiety of being re-strug, in the Visual Analogue Scale--VAS score; 3) identification of factors influencing changes in the fear level among patients during VIT.

MATERIAL AND METHODS

The study group comprised 42 patients (18 women, 24 men) in the mean age 42.6 years, with bee or vespid allergy, who had been qualified to the VIT treatment with Alutard SQ. Visual Analogue Scale--VAS and the Expectation of Outcome Questionnaire were used. The demographic data were collected.

RESULTS

The VAS score before VIT for insect venom allergic patients was 8.8 (SD = 0.9). It decreased after achieving maintenance dose to 3.1 (SD = 1.6) and was significantly lower in men (p < 0.05). Score achieved in the Expectation of Outcome Questionnaire was for each question 2.2 (SD = 1.5) and there was correlation with VAS score during VIT.

CONCLUSIONS

The patients with insect venom allergy, who undergo a serious allergic reaction (SR) as a result of being stung and who are qualified to VIT, have a high level of anxiety of being re-stung. Achieving the maintenance dose of VIT, results in a significant decrease of anxiety level in women and men, significantly so in men. There is a significant correlation between VAS score and the Expectation of Outcome Questionnaire results during VIT. Both VAS for anxiety level and the Expectation of Outcome Questionnaire can be simple, easily available and useful instruments helping to estimate quality of life. VIT significantly decreases the patients level of anxiety of being restung and improves their quality of life.

Blood pressure modulation following activation of mast cells by cationic cell penetrating peptides

Short cell penetrating peptides (CPP) are widely used in vitro to transduce agents into cells. But their systemic effect has not been yet studied in detail. We studied the systemic effect of the cell penetrating peptides, penetratin, transportan and pro-rich, on rat hemodynamic functions. Intra-arterial monitoring of blood pressure showed that injection of the positively charged penetratin and transportan in a wide range of concentrations (2.5-320 μg/kg) caused highly significant transient decrease in the systolic and diastolic blood pressure in a dose dependent manner (p<0.01). Pretreatment with histamine receptors blockers or with cromolyn, a mast cell stabilizing agent, significantly attenuated this effect. Furthermore, in vitro incubation of these both peptides with mast cells line, LAD2, caused a massive mast cell degranulation. In vitro studies showed that these CPP in a wide range of concentrations were not cytotoxic without any effect on the survival of LAD2 mast cell line. In contrast, the less positively charged and proline-rich CPP, pro-rich, had no systemic effects with no effect on mast cell degranulation. Our results indicate that intravenously administrated positively charged CPP may have deleterious consequences due to their induced BP drop, mediated by mast cell activation. Therefore, the major effect of mast cell activation on BP should be considered in developing possible future drug therapies based on the injection of membrane-permeable and positively charged CPP. Nevertheless, lower levels of such CPP may be considered as a treatment of systemic high BP through moderate systemic mast cell activation.

Maintenance venom immunotherapy administered at a 3-month interval preserves safety and efficacy and improves adherence

BACKGROUND

Hymenoptera venom immunotherapy (VIT) is a safe and effective approach to insect sting allergy. However, after discontinuation, relapses can occur in some patients, especially those with a high occupational risk, and they may need to prolong VIT indefinitely. In order to improve adherence, we propose extending the interval between injections of maintenance VIT (MVIT).

OBJECTIVE

To evaluate the safety, efficacy, and patient acceptance of a 3-month interval between MVIT injections in a group of Hymenoptera-allergic patients who are occupationally exposed to insect stings.

PATIENTS AND METHODS

We included 72 patients with severe systemic reactions to Hymenoptera stings. MVIT was administered for 4 years at intervals increasing up to 3 months and then continued for a further 2 years. Patients were informed of the risk of relapse after discontinuation and of the need for indefinite treatment at 3-month intervals.

RESULTS

During the 3-month interval maintenance phase, only 235 local reactions (17.8%) were observed in 17 patients. Sixty patients experienced 125 field re-stings and only 1 experienced a systemic reaction with generalized urticaria.

CONCLUSIONS

The study confirms that the conventional MVIT interval of 4 to 6 weeks can be extended to 3 months in most patients with no adverse events, while maintaining safety and efficacy, improving adherence, and guaranteeing safe continuation of professional activity.

Venom of Pteromalus puparum (Hymenoptera: Pteromalidae) induced endocrine changes in the hemolymph of its host, Pieris rapae (Lepidoptera: Pieridae)

Pteromalus puparum is a predominant endoparasitoid wasp of Pieris rapae. Its venom is the only active factor injected into host associated with oviposition. In this report, we explored whether the venom alone from this wasp affects the endocrine system of its host or not. We monitored the changes of hemolymph juvenile hormone (JH; only JH III detected), ecdysteroid, and juvenile hormone esterase activity (JHE) over 72 h in parasitized and venom-microinjected P. rapae pupae. Non-parasitized and PBS-microinjected P. rapae served as controls. Results showed that JH titers were significantly higher in parasitized and venom-microinjected pupae than that in control pupae during 24 to 72 h. After 12 h, JH titers were significantly promoted by parasitization and venom microinjection. JHE activities of non-parasitized and PBS-microinjected pupae were significantly higher than that of parasitized and venom-microinjected pupae, which was with a peak at 12 h (parasitized pupae) or 24 h (venom-microinjected pupae) during 6 to 48 and 12 to 36 h, respectively. The hemolymph titers of ecdysteroid in non-parasitized and PBS-microinjected pupae increased rapidly during 12 to 36 h with a peak at 36 h, and were higher than treatments before 48 h, while presenting a significant difference at 24 to 48 h between the treatments and controls. The results demonstrate that venom alone of this parasitoid wasp can disrupt its host's endocrine system.

Influence of nutrient deficiency caused by host developmental arrest on the growth and development of a koinobiont parasitoid

Koinobiont parasitoids utilize nutrients obtained from hosts that contine to feed and grow after parasitization. However, if the ecdysis of early host instars is prevented, parasitized larvae will fail to grow large enough to support the development of the parasitoid brood and both organisms will perish. When L5 instar larvae (the penultimate stage) of Pseudaletia separata were parasitized by Cotesia kariyai and injected with Euplectrus separatae venom (5PV), the development of these hosts was arrested before molting to the next stage and the caterpillars thus failed to gain weight. These hosts remained at approximately 300 mg until parasitoid emergence. In contrast, hosts parasitized as L5 but without the injection of venom (5P) exhibited an increase in weight after molting to the next stage and ultimately grew to approximately 700 mg. The inhibition of ecdysis reduced the amount of food resource (e.g. fat body) for the parasitoid larvae. On the other hand, when final (= L6) host instars were parasitized and injected with E. separatae venom (6PV), the maximum weight attained by these larvae was about 710 mg, although weight gain was depressed compared to hosts parasitized without the injection of E. separatae venom (6P). The adult weight of C. kariyai that emerged from 5PV hosts was less than conspecifics that emerged from 5P, 6P, and 6PV respectively, although the egg-pupal period of the parasitoid from 5PV hosts was extended. The offspring sex ratio (percentage males) of adult wasps did not vary significantly with treatment. Female parasitoids that eclosed from 5PV hosts laid almost the same number of eggs in day 0-6th host instars as those emerging from 5P, 6P, 6PV hosts. Their egg-pupal period was extended and the cocoon cluster mass and the parasitoid body mass on subsequent generations was lighter than those reared from 5P, 6P, 6PV hosts. The sex ratio of F2 C. kariyai wasps that eclosed from 5PV increased more than in wasps that eclosed from the other host treatments (5P, 6P, 6PV). Our results reveal that a reduction in host quality and offspring fitness in the first generation negatively impacted female fitness in the second generation. An early arrestment of host growth, mediated by the addition of E. separatae venom, has severe implications on parasitoid fitness by reducing host quality, especially in smaller hosts.

Ultra-rush venom immunotherapy induces differential T cell activation and regulatory patterns according to the severity of allergy

BACKGROUND

Venom immunotherapy (VIT) induces immune tolerance to hymenoptera venom antigens in allergic patients and is therefore a helpful model for studying modulation of allergic immune response. The objectives were to assess the early effects of ultra-rush VIT on T lymphocyte activation and regulatory profile induction, in all subjects combined and according to the four severity grades of the Mueller classification.

MATERIALS AND METHODS

Blood samples from 30 vespid-allergic patients were taken before and after the first day of treatment, and before day 15 and day 45 booster injections. IFN-gamma and IL-4 levels were assayed by ELISA, in whole-blood supernatants. IFN-gamma and IL-13-producing T cells, but also natural CD4+CD25+high regulatory T cells and acquired regulatory T cell proportions were assessed by flow cytometry. Results were analysed in the whole population and compared between patients with I-II or III-IV allergic reactions.

RESULTS

During VIT, IFN-gamma increased in whole blood when IL-4 decreased. Among T cells, the percentage of CD3+IFN-gamma+ cells increased while IL-13-producing T cells decreased. Proportions of CD4+CD25+high cells and IL-10-producing T cells increased with VIT. In I-II subjects, IFN-gamma increased gradually, whereas it remained at low levels in III-IV patients. By contrast, IL-4 decrease was more pronounced in III-IV patients. Increase in CD4+CD25+high T cells occurred early in I-II patients but was delayed in III-IV patients. IL-10-producing T cells increased gradually in both groups but were in a lower proportion in III-IV patients.

CONCLUSION

A T helper type 2 (Th2)-to-Th1 switch occurs during ultra-rush VIT, in parallel with natural and acquired regulatory T cell increase. These events occur earlier and at a higher level in less severe subjects, suggesting that VIT tolerance induction is easier to achieve in these patients.

Flexible approaches in the design of subcutaneous immunotherapy protocols for Hymenoptera venom allergy

BACKGROUND

Venom immunotherapy is an effective method for the treatment of Hymenoptera venom allergy. Different extracts and treatment schedules are available.

OBJECTIVE

To compare the safety and efficacy of immunotherapy in 3 cohorts of patients sensitized to Vespula species.

METHODS

In this open study, 43 patients were treated with a subcutaneous aqueous extract for induction and maintenance (AA), 34 with a subcutaneous depot extract for induction and maintenance (DD), and 29 with subcutaneous aqueous and subcutaneous depot extracts for induction and maintenance, respectively (AD). Cluster schedules were followed to reach maintenance, and adverse effects during treatment and after naturally occurring stings were recorded.

RESULTS

Depot immunotherapy was better tolerated mainly owing to the lower frequency of local adverse effects in the induction phase (5.9% vs 42.5% and 1.3% vs 5.1% on a per patient and per dose basis, respectively; P < .001 for both) and for effects occurring within 60 minutes after vaccination (2.9% vs 19.2% and 0.2% vs 2.8% on a per patient and per dose basis; P = .03 and P < .001, respectively). Furthermore, 19 of 20 AA, 9 of 9 AD, and 10 of 10 DD patients who were restung experienced only minor local effects.

CONCLUSIONS

Venom immunotherapy is efficacious. Although there was no decrease in systemic reactions, depot immunotherapy to Vespula venom induced fewer early local adverse effects. Patients undergoing an induction phase with an aqueous extract can benefit from switching to a depot extract during maintenance. Increasing the flexibility of the immunization schedules may improve compliance with this potentially lifesaving treatment.

A modified ultrarush insect venom immunotherapy protocol for children

The prevalence of insect venom allergy in the European population is approximately 5%. Hymenoptera venom allergy is an important epidemiological problem. Ten to 40 deaths are reported annually in Germany. In contrast to conventional dose increase schedules lasting a minimum of 5 days, shorter protocols reduce the patient's stay in the hospital and provide an earlier protection toward stings. Clinical studies on ultrarush protocols have been published for adult patients, but very little data are currently available for children. Therefore, we investigated the safety and tolerability of a shortened insect venom immunotherapy (VIT) in children and adolescents. Forty-three children and adolescents (aged 4-18 years) with insect venom allergy were treated in this study. Five children were hyposensitized according to the ultrarush protocol with nine injections (as suggested by Brehler et al. (Safety of a two-day ultrarush insect VIT protocol in comparison with protocols of longer duration and involving a larger number of injections. J Allergy Clin Immunol 105:1231-1235,2000); 38 children received the modified ultrarush schedules with only eight subcutaneous injections. With both protocols the maintenance dose (100 microg) was achieved in 24 hours. Twenty-five patients (58.1%) showed no reaction after the injections. In 11 patients (25.6%), extensive erythema (>5 cm, maximum of 20 cm) was found at the injection site. Erythema and edema (>5 cm, maximum of 15 cm) were observed in seven patients (16.2%). The maintenance dose was well tolerated, with no systemic reaction in any patient. The modified ultrarush protocol for insect VIT used in this study showed very good tolerability and safety in children and adolescents. This dose regimen can increase compliance by shortening inpatient stay and reduces hospital costs.

Development of new IgE specificities to hymenoptera allergens during venom-specific immunotherapy

BACKGROUND

Despite the benefits of specific immunotherapy (SIT) being clinically well documented for allergic diseases, new IgE specificities to SIT extract allergens could be induced during the treatment. The authors evaluated these changes in patients allergic to Hymenoptera.

METHODS

Six patients allergic to Hymenoptera venom were included in the study. Specific IgE (sIgE) levels determination and IgE immunoblots to Apis mellifera, Vespula spp. and Polistes spp. venom were performed before and after one year of SIT.

RESULTS

All patients had sIgE levels reduction, after the first year of treatment, except one in whom there was an increase in sIgE levels to Apis mellifera venom, and two patients that maintained a similar value for Vespula spp. venom sIgE before and after one year of treatment. The immunoblot analysis revealed that most of the bands detected before beginning SIT, decreased in intensity or disappeared after one year of treatment. 3/6 patients developed new IgE specificities to venom extracts: one patient to the venom allergens in the treatment, other patient to allergens in other venom and another patient to both. After one year of treatment one of these patients tolerated a field sting by the corresponding insect. The newly recognised proteins were all minor allergens.

CONCLUSION

These results confirm that sIgE levels tend to reduce during SIT, and the bands identifying some allergens in the blot tend to decrease or disappear. Nonetheless venom SIT can be responsible for the induction of new sensitisations to other venom allergens, apparently without clinical relevance.

Kinetics and dynamic evaluation of specific immunotherapy

Specific immunotherapy (SIT) is frequently used in the treatment of allergic diseases. However, the mechanisms by which SIT achieves clinical improvement remained unclear. We decided to study the in vivo kinetics of this therapy, using a nuclear medicine approach (leukocytes labelled with 99mTc-HMPAO) in patients on maintenance doses of specific immunotherapy with confirmed clinical efficacy.

MATERIAL AND METHODS

We studied 13 allergic patients grouped according to different treatment schedules: subcutaneous aqueous allergenic extract (3 latex and 2 hymenoptera venom), subcutaneous depot extract (2 house dust mite and 2 pollens), subcutaneous modified allergens (2 pollens), sublingual extract (2 house dust mites). The control group included two allergic patients submitted to subcutaneous injections of bacterial extract (1 patient--positive control), and aqueous solution (1 patient). At the same time that the therapeutic allergen was administered subcutaneously, the autologous labelled white cells were injected intravenously in a peripheral vein in the contralateral arm. A thoracic dynamic acquisition of 60 mins, 64x64 matrix, 2 frame/min, in anterior view was performed. Static acquisition for 256x256 matrix, during 5 mins each at 60, 90, 120, 180, 240, 300 and 360 mins after the administration of the radiolabelled leukocytes, in thoracic (anterior and posterior), and abdominal view were performed. During the examination, the local erythema was monitored. A similar procedure was undertaken for Sublingual administration of immunotherapy.

RESULTS

The inflammatory activity at the site of SIT injection (aqueous depot extract) started in the first hour and the increase was time related. For modified allergen extract and sublingual SIT the activity was present since the beginning of the administration. The ascendant lymphatic drainage, which was directed to the homolateral axillary region, to the lymphoid tissue of the upper mediastinum and to the anterior region of the neck began earlier. Thoracic focalisations were present for all the patients, whereas bowel focalisations were only observed for the subcutaneous route of administration. Sublingual SIT did not induce axillary or intestinal inflammatory focalisations, even though the patients had swallowed the allergenic extract. The uptake coefficient in individualized areas corrected to the uptake coefficient background was also studied.

CONCLUSIONS

For the subcutaneous route of administration, except for glutaraldehyde-modified allergen, the local inflammatory activity at the allergenic injection site was significantly higher in depth and was time dependent, maintaining activity even after complete disappearance of the erythema and/or wheal. These results express a prompt inflammatory involvement of the immune system with this allergenic therapy, which was unexpected until now. We also observed differences concerning allergic diseases, the type of allergenic extracts and routes of administration.

Specific ultrarush desensitization in Hymenoptera venom-allergic patients

BACKGROUND

Hymenoptera venom hypersensitivity is an epidemiologically important problem. The only effective treatment in the management of venom-allergic patients with a history of generalized reactions to insect sting is specific immunotherapy.

OBJECTIVE

To demonstrate safety and effectiveness of a modified ultrarush desensitization protocol in venom-allergic patients.

METHODS

Fifty-seven patients with Hymenoptera venom allergy underwent a specific 1-day ultrarush desensitization by the subcutaneous route, reaching the cumulative dose of 101.1 microg in 2.5 hours. The maintenance dose (100 microg) was administered after 15 days and thereafter once a month. Patients were followed up for a year. Antihistamines were withheld for 15 days before and during desensitization to not underestimate the incidence of adverse effects.

RESULTS

All patients but I completed the ultrarush desensitization. (This patient discontinued the treatment because of a hypertensive crisis not related to the desensitization.) The treatment caused a rapid variation of immunological parameters (IgE, IgG4) since the 15th day. After the desensitization, skin prick test results became negative in 15 patients (27%, decrease of 3.5 log), whereas they decreased in 14 patients (25%, decrease of 1 log). Sixty-four percent showed no adverse effects. Only 7% had a mild systemic reaction.

CONCLUSIONS

Ultrarush desensitization is an effective and safe therapy in the management of patients with Hymenoptera venom allergy. In fact, it provides a faster tolerance, without significant differences regarding incidence of severe adverse effects, compared with traditional and rush protocols. It can be adopted for all patients, even children and teenagers.

[A modified ultra-rush-protocol of allergen immunotherapy in children and adolescents with insect venom allergy]

BACKGROUND

In Germany the prevalence of insect venom allergy in the population is about 5 %, 10-40 deaths are reported every year. With a success rate of 95 % venom immunotherapy (SIT) has a convincing protective effect. The purpose of this study was to investigate the safety of the original ultra-rush-protocol in children and reduce from 9 to 8 doses by avoiding a second application of 100 micro g insect venom.

METHODS

Nineteen children and adolescents with insect venom allergy were treated according to the modified ultra-rush-protocol. The first 5 children were hyposensitized according to the original protocol suggested by Brehler et al., the remaining 14 children (age 6-18 years) received only 8 injections (0.01/0.1/1/10/20/40/80/100 micro g). 5 patients were discharged on the second day four hours after the final application of 100 micro g insect venom.

RESULTS

Extensive reddening due to inflammation was found in injection spot in 5 patients. Four patients had an amplified wheal formation. No systemic reactions were observed. The maintenance therapy was well tolerated.

CONCLUSION

The modified ultra-rush-protocol increases compliance by short inpatient stay. In addition the modified hyposensitization was sure and well tolerated.

Rush venom immunotherapy in patients experiencing recurrent systemic reactions to conventional venom immunotherapy

BACKGROUND

An unknown number of venom-allergic patients fail to reach the maintenance dose (MD) during the build-up period of conventional venom immunotherapy (VIT) due to recurrent systemic reactions (SRs).

OBJECTIVE

To establish an alternative VIT protocol that will enable these patients to reach a full protective MD.

METHODS

Venom-allergic patients who had experienced recurrent SRs during the build-up period of conventional VIT underwent rush VIT.

RESULTS

Of the 9 patients who participated in this study, the 6 who underwent 8 treatment courses tolerated the rush VIT well and reached the MD within 3 days. In 3 of these patients, mild cutaneous SRs were overcome with loratadine. In 2 patients who experienced recurrent and more severe SRs, the original 3-day rush VIT had to be modified and extended to 5 days until the MD was reached. In a single patient who experienced an anaphylactic reaction, VIT was discontinued.

CONCLUSIONS

Rush VIT is an appropriate therapeutic alternative that enables most patients with recurrent SRs throughout the build-up period of conventional VIT to reach a full protective MD.

Safety of rush insect venom immunotherapy. The results of a retrospective study in 178 patients

BACKGROUND

Venom immunotherapy (VIT) is regarded as an established and efficient treatment of Hymenoptera venom allergy. Different frequencies of side-effects have been reported in the literature, depending on the hyposensitization regimen (conventional outpatient programme, rush immunotherapy, ultra rush immunotherapy) and the venom preparation. Aim of this study was to evaluate safety and tolerance of rush VIT in patients treated with a 7-day protocol in our department.

METHODS

VIT protocols of 178 patients treated at the Department of Dermatology and Allergy of the University of Bonn were analysed retrospectively. All patients had been treated with a standardized venom preparations (ALK-SQ). We used a modified VIT-protocol with a 2-day break to reduce systemic side-effects.

RESULTS

During the course of VIT in 15 patients (8.4%) systemic reactions grade I (Mueller scale) were observed, in seven (3.9%) grade II, in six (3.4%) grade III and in four (2.2%) grade IV. A total of 146 patients (82.1%) had no or only local reactions.

CONCLUSIONS

The rate of systemic adverse reactions Mueller Grade I-IV of 17.9% of the 'Bonn rush VIT protocol' appears to be relatively low compared with the data in the literature.

Direct injection of venom by a predatory wasp into cockroach brain

In this article, we provide direct evidence for injection of venom by a wasp into the central nervous system of its cockroach prey. Venomous predators use neurotoxins that generally act at the neuromuscular junction, resulting in different types of prey paralysis. The sting of the parasitoid wasp Ampulex compressa is unusual, as it induces grooming behavior, followed by a long-term lethargic state of its insect prey, thus ultimately providing a living meal for the newborn wasp larvae. These behavioral modifications are induced only when a sting is inflicted into the head. These unique effects of the wasp venom on prey behavior suggest that the venom targets the insect's central nervous system. The mechanism by which behavior modifying compounds in the venom transverse the blood-brain barrier to induce these central and long-lasting effects has been the subject of debate. In this article, we demonstrate that the wasp stings directly into the target ganglia in the head of its prey. To prove this assertion, we produced "hot" wasps by injecting them with (14)C radiolabeled amino acids and used a combination of liquid scintillation and light microscopy autoradiography to trace radiolabeled venom in the prey. To our knowledge, this is the first direct evidence documenting targeted delivery of venom by a predator into the brain of its prey.

High efficacy and absence of severe systemic reactions after venom immunotherapy

The efficacy of immunotherapy with venom (ITV) is supported by many studies. However, the key point for ITV is the balance between safety and efficacy, as concern for adverse events may restrict its use, and limit the administration of this treatment to the hospital, exclusively. The objectives of the present study were, first, to analyze the characteristics and incidence of ITV-related adverse events and to determine whether the administration of this treatment exclusively in hospitals is justified, and second, to assess the efficacy of a semi-rush dosage schedule, which is being used in our department. We analyzed the data of 241 patients with known allergy to hymenoptera venom (208 sensitive to Apis mellifera and 33 to Vespula spp.), who were treated with ITV (Pharmalgen, ALK-ABELLO) for an average period of 32 months. The initial treatment was performed at the Allergy Department, administering nine increasing doses of the venom once or twice a week. Maintenance treatment, whenever possible, was performed at primary care centers (PCCs). In this study, 95 patients (39%) were referred to their corresponding PCC. A total of 3697 doses were administered, and 37 systemic reactions (SR) and 37 local reactions (LR) were recorded; the overall frequency of occurrence of adverse events was 1.97%, 1% corresponding to SR, and 1% related to LR. The severity of most of SR was mild and the response to treatment with oral antihistamines and corticoids was good. Administration of adrenaline was required in 14 cases. Regarding the maintenance treatment administered at PCCs, only two adverse events were recorded, one case of vaso-vagal symptomatology and one case of urticaria-like reaction two hours after the administration. Eighty-four cases of spontaneous field stings, corresponding to 58 patients, were reported; in 82 cases (97.6%) the reaction was less severe than that experienced before the administration of ITV. The severity of the other two reactions was the same as previously recorded, though they occurred in patients during the build-up phase of the treatment. In any case, a reaction with a higher grade of severity was recorded. The dosage schedule administered is efficient, the frequency of occurrence of adverse events is low, their intensity is generally mild, and minimum medication is required to control them (antihistamines, corticosteroids). Taking into account the tolerance observed during the maintenance treatment, we consider that its administration at PCCs is appropriate.

Clustered schedules in allergen-specific immunotherapy

BACKGROUND

Injective immunotherapy is traditionally performed with a build-up phase lasting 3 to 4 months. The costs, decreasing compliance from both patients and clinicians and inconveniences due to this schedule may be overcome using different schedules.

METHODS AND RESULTS

A revision of the published papers with clustered schedules has been made. Attention has been focussed on tolerance and its relationships with relevant parameters such as kind of extract (aqueous or depot), allergens and their pharmaceutical presentation, schedule followed, use or not of a premedication, clinical manifestations of patients before treatment. For a better revision, papers dealing with clustered schedules have been divided into two groups. The first group includes 20 papers not designed to study the clustered schedule but using it to study other parameters affected by specific immunotherapy. The second group includes 9 papers specifically or mainly designed to study the clustered schedule. A huge difference in the rate of side effects could be assessed among different papers, even in studies run with similar allergens from the same producer and with a similar schedule.

CONCLUSIONS

Summarizing the results of the revision, the following conditions seem to lead to the optimal tolerance of the clustered schedule: use of a premedication; use of a depot preparation; use of no more than 4 administrations per cluster; administration of 1-2 clusters per week and of 4 to 6 clusters in total. These results seem promising but further efforts are required to better define the optimal clustered schedule.

Specific immunotherapy in Albanian patients with anaphylaxis to hymenoptera venoms

BACKGROUND

Severe allergic reactions during rush-specific immunotherapy (Rush-SIT) may occur in the treatment of hymenoptera sting allergy. The objective of the present study was to examine the characteristics of allergic reactions during Rush-SIT in a cohort of patients with allergy towards hymenoptera venom in the mediterranean population of Albania.

METHODS

A retrospective study was performed using the clinical reports of 37 patients with venom of bee (apinae), wasp (vespidae, subfamily vespinae) or paperwasp (vespidae, subfamily polistinae) allergy treated with Rush-SIT between 1987 and 1996. After hymenoptera sting allergy diagnosis according to anamnesis and intracutaneous tests the patient were treated with Rush-SIT. The protocol lasted 3 - 4 d with an increase in the concentration from 0.01 microg/ml to 100 microg/ml. Anaphylactic reactions were classified according to the Mueller-classification.

RESULTS

The frequency of reactions during Rush-SIT for bee-venom was 4.7% and for wasp-venom was 1.5% (p < 0.01). The mean frequency of reactions of Mueller grade II for the bee-venom Rush-SIT patients during the first 4 d (= 26 injections) was 0.73 and for the wasp-venom Rush-SIT patients 0.15. No patient experienced a third-degree reaction. 94.6% of the patient supported an end dose of 100 microg.

CONCLUSIONS

Rush-SIT is a reliable method for the treatment of anaphylactic reactions to hymenoptera venom even in less developed countries. Bee-venom Rush-SIT was found to cause higher numbers allergic reactions than wasp or paperwasp Rush-SIT.

Venom immunotherapy improves health-related quality of life in patients allergic to yellow jacket venom

BACKGROUND

Venom immunotherapy (VIT) is effective in preventing anaphylactic reactions after insect stings. The effect of VIT on health-related quality of life (HRQL) was studied to evaluate whether this treatment is of importance to patients.

OBJECTIVE

We compared HRQL outcomes measured with a disease-specific instrument (Vespid Allergy Quality-of-Life Questionnaire [VQLQ]) in patients allergic to yellow jacket venom treated with VIT or with an adrenalin self-administration device (EpiPen) in an open-label, randomized, controlled trial.

METHODS

Consenting patients were block randomized to either VIT or EpiPen. Patients received uniform, standardized information, which specified the risk of their condition and the risks and benefits of both treatment options. HRQL measures took place before and after 1 year of treatment with VIT or EpiPen.

RESULTS

Seventy-four patients agreed to be randomized, of whom 36 received VIT and 38 an EpiPen. The mean change in VQLQ score in the group randomized to VIT was 1.07 (95% CI, 0.68-1.46), and this improvement was statistically significant (P <.0001) compared with that seen in the group randomized to the EpiPen, in which this change was -0.43 (95% CI, -0.71 to -0.16). These differences were seen in both men and women, persons with more or less general anxiety, and those stung recently and those stung more than a year before their outpatient department visit. The overall proportion of patients receiving benefit from VIT is 0.72, generating a number needed to treat of 1.4.

CONCLUSIONS

VIT results in a clinically important improvement in HRQL in patients allergic to yellow jacket venom in all subgroups studied. Of every 3 patients treated with VIT, 2 patients experience an important improvement in their quality of life.

Might wasp venom desensitization induced Th2 to Th1 shift cause pregnancy failure?

The case of a 28-year-old woman under wasp venom desensitization having a premature birth in her 24th week of pregnancy 16 days after the last injection is described. To test the hypothesis that a special profile of immune cells in the decidua may trigger abortions, placental and decidual tissue sections were stained with antibodies against T cells (CD3), cytotoxic cells (CD8), natural killer cells (CD56), and mast cells, and an in-situ-hybridization was performed for tumor necrosis factor-alpha (TNF-alpha). CD56+ Natural killer cells were the dominating population. In earlier analyses of healthy first trimester decidua the percentage of NK cells and T cells was in a similar range, but the CD8:CD3 ratio was only 2.2% in contrast to 27% in the present case. Mast cells, which are known to be able to secrete abortogenic TNF-alpha, were only detectable in the decidua (10 cells/mm2) and decidua sections were TNF-alpha positive. Since SIT induces a shift of the interleukin and functional profile from a Th2 type towards a Th1 type, and pregnancy is dependent on a Th2 pronounced profile, SIT may trigger abortions or immature births. This is supported by the present results and might have happened in this case.

The safety and efficacy of immunotherapy with aluminum hydroxide-adsorbed venom extract of Vespula spp. An open, retrospective study

BACKGROUND

specific immunotherapy for Hymenoptera Venom (VIT) is considered a life-saving treatment in insect sting allergy. A few studies with depot VIT have been published, but they are mainly focussed on patients sensitized to Apis.

METHODS

this retrospective study was designed to evaluate both efficacy and safety of depot VIT for Vespula. Thirty-six patients (age range 6-73 years) with a history of systemic reactions (grade III to IV according to Mueller) after a Vespula sting, and specific sera IgE RAST to Vespula at least class 2, were administered a depot preparation of venom reaching 50 microgram as monthly maintenance dose. After the first year the maintenance dose was administered every other month. Thirty-three patients were treated for a minimum of 5 years. Reactions to any new field sting of the relevant insect were recorded during the treatment and for 6 to 24 months after its interruption.

RESULTS

the treatment showed an excellent tolerance, with only a few local side effects. Thirteen patients (11 Grade IV according to Mueller before VIT) under treatment showed only local reactions after each field sting (18 field stings in total) by the relevant insect. Four patients (3 Grade IV according to Mueller before VIT) had a total of 6 field stings after the interruption of the 5-year treatment, with only local reactions.

CONCLUSIONS

according to our results, and in agreement with previous published studies, VIT for Vespula spp. with depot extracts has an excellent tolerance and is clinically effective.

Aluminium-induced granulomas after inaccurate intradermal hyposensitization injections of aluminium-adsorbed depot preparations

BACKGROUND

The development of persistent subcutaneous nodules at the injection sites of aluminium-adsorbed hyposensitization solutions is rare. These nodules have been interpreted as a delayed, granulomatous hypersensitivity reaction to aluminium. We report for the first time a case of persistent intradermal granulomas that developed at the sites of inaccurate intradermal, instead of subcutaneous, hyposensitization injections.

METHODS

An intradermal nodule was excised and processed for histopathology, scanning electron microscopy, and X-ray microanalysis. Intradermal and patch tests with aluminium hydroxide were performed.

RESULTS

Histologically, the nodule presented a pattern of granulomatous inflammatory reaction surrounding foci of necrotic tissue. Scanning electron microscopy and X-ray microanalysis revealed deposits of aluminium within the granulomas. Patch tests with aluminium hydroxide were negative, and intradermal tests caused persistent intradermal granulomas. Subsequent hyposensitization therapy in our department with the usual subcutaneous injections of aluminium-adsorbed allergen extracts was well tolerated by the patient.

CONCLUSIONS

Local toxic effects of aluminium may be crucial in the development of persistent intradermal injection-site granulomas. Such intradermal nodules may develop even if the subcutaneous route is well tolerated. We conclude that inaccurate intradermal injections of aluminium-containing solutions have to be strictly avoided.

[Specific immunotherapy (hyposensitization) with insect venom in pregnancy]

BACKGROUND

Pregnancy typically prohibits the specific immunotherapy (SIT) of various allergic conditions, with the exception of pre-existing Hymenoptera venom allergies. International consensus currently recommends the continuation of a well-tolerated SIT with insect venom during pregnancy, since there is a significant risk of anaphylaxis after insect stings with potentially dismal outcomes for mother and fetus.

CASE REPORT

We report on a 28-year old woman, becoming pregnant during specific immunotherapy with Hymenoptera venom. SIT was continued during pregnancy and a premature birth occurred at the 24th week.

DISCUSSION AND CONCLUSION

Unfortunately, there are still conflicting opinions in Germany regarding SIT during pregnancy, and the decision to perform such therapy is entirely based on knowledge and/or level of comfort of the primary physician. Thus, obstetricians should closely work together with an allergologist in cases of pregnant women with insect sting allergies.

Evaluation of the risk of anaphylactic reactions by wasp venom-extract challenges in children

Diagnostic sting challenges have been shown to provide information on the risk of further anaphylactic reactions to bee stings. We present a follow-up study in wasp venom-hypersensitive children after diagnostic venom extract challenges to analyze their risk of further anaphylactic reactions. Responses were obtained from 104 patients with wasp venom hypersensitivity out of 115 former patients. Only one of the 104 patients showed more than a severe local reaction to the sting challenge irrespective of the performance of a single or sequential challenge; therefore, only one patient received venom immunotherapy. The performance of a diagnostic sting challenge with wasp venom extract in children had a high negative predictive value of 94.6% for the risk of further systemic reactions. This was shown by analysis of later field stings, since 37 children experienced further field stings and only two of these children(5.4%) developed a mild systemic reaction (urticaria) equal to or less severe than the index sting. The value of the venom extract challenge can be interpreted in two ways: either it is less sensitive than a native sting challenge since the rate of systemic reactions to the challenge was very low, or the prognosis of wasp venom hypersensitivity in children is extremely favorable. Since the latter hypothesis is supported by the low incidence of systemic field sting reactions, we postulate that venom immunotherapy is necessary only in a minority of children with wasp venom hypersensitivity with an index sting reaction of Mueller grade I or II. However, the value of venom extract challenges as a general diagnostic instrument in children with Mueller I and II reactions due to wasp venom hypersensitivity may be questioned. It may have a place as a safe procedure in demonstrating to parents and physicians the often self-limiting natural course in most of these children.

Discontinuation of yellow jacket venom immunotherapy: follow-up of 75 patients by means of deliberate sting challenge

BACKGROUND

Venom immunotherapy is effective in preventing systemic reactions in patients with a history of an anaphylactic reaction to Hymenoptera stings. It is uncertain how long venom immunotherapy should be continued.

OBJECTIVE

We evaluated whether the duration of venom immunotherapy given to yellow jacket-sensitive patients related to the risk of an anaphylactic reaction to a later sting.

METHODS

Seventy-five yellow jacket-sensitive patients (29 male and 46 female) received a median number of three in-hospital sting challenges from a live insect in 3 subsequent years after discontinuation of venom immunotherapy. An anaphylactic reaction to one or more of the sting challenges was considered a relapse. We analyzed whether patients with and patients without a relapse differed in terms of gender, age, preimmunotherapy skin test data, preimmunotherapy level of venom-specific IgE, severity of the field-sting reaction that preceded immunotherapy, severity of the reaction to the sting challenge that preceded immunotherapy, adverse reactions to immunotherapy, changes in IgE and IgG4 levels during immunotherapy, duration of immunotherapy, and presence of venom-specific IgE after cessation of therapy.

RESULTS

Venom immunotherapy was given for a median duration of 40 months (range, 7 to 120 months). Relapses were observed in six patients. In two of them, a rather severe anaphylactic reaction was observed after the second sting challenge. No relation was found between duration of venom immunotherapy and relapse risk. The relapse rate was higher among patients with high levels of specific IgE before and after immunotherapy. During therapy, the mean level of specific IgE decreased. This decline persisted in the 3 following years. No relapses of sting reactions were observed among patients without detectable specific IgE.

CONCLUSION

Discontinuation of venom immunotherapy appears safe for patients with pretreatment IgE antibodies if these antibodies can no longer be detected during immunotherapy. For the remaining patients, a treatment period of 3 years may suffice. After discontinuation of immunotherapy, a clinical sting challenge can be considered to estimate the patient's current grade of hypersensitivity.

[Standardized rapid hyposensitization with purified hymenoptera venom in wasp venom allergy. Prospective study of development of tolerance and side-effect profile]

In Germany, insect allergies cause about 10-40 death per year. Starting a specific immunotherapy (SIT) and its maintenance may be lifesaving for the allergic patients. Performing a prospective study, we exactly documented effects and side effects during the induction phase of SIT using a purified aqueous yellow jacket venom preparation in 20 patients allergic to yellow jacket venom (clinical degree II-IV). Indication for the therapy was defined individually for each patient and was based on a score incorporating the following criteria: a) clinical symptoms, b) in-vivo- and in-vitro testing, c) risk of re-sting. SIT was started under inpatient conditions following a standardized 8 day protocol. At the end of the induction phase all patients tolerated the maintenance dose of 100 micrograms of yellow jacket venom without complications even though all showed local side effects (threshold doses 0.01-10 micrograms, median value 0.2 microgram). 40% of all patients showed subjective side effects (median value of threshold dose 30 micrograms, range 0.2-60 micrograms) and 30% showed objective side effects (median value of threshold dose 55 micrograms, range 20-80 micrograms); however, all side effects were clinically mild. When objective systemic side effects were seen, the cumulative daily dose was 39-210 micrograms (median value 135 micrograms), exceeding 100 micrograms in 83% of patients. Our prospective study confirmed that the chosen protocol for SIT is effective in inducing tolerance to the venom preparation. However, using a purified aqueous yellow jacket preparation did not result in reduction of side effects.

Wasp venom immunotherapy changes IgG antibody specificity

BACKGROUND

The evolution of the IgG response during venom immunotherapy (VIT) has been previously investigated in terms of antibody titres and subclasses.

OBJECTIVES

The present work studied the evolution of IgG antibody fine specificity in wasp allergic patients treated with rush VIT.

METHODS

Antibody specificity was evaluated in 51 wasp allergic patients in competitive ELISA using streptavidin biotin technology. Patients were tested before and during specific rush immunotherapy (at 15 days, 6 months, 12 months) and compared with 44 patients treated by venom injections for at least 2 years.

RESULTS

The capacity of sera to prevent the antigen binding of pooled IgG from allergic patients changed rapidly with mean percentage inhibitions (+/-SD) falling from 70+/-11-51+/-18% after 15 days of treatment (P<0.001 by one way ANOVA). Similarly, the antigen binding capacity of pooled IgG from VIT patients was differently prevented by sera with mean percentage inhibitions increasing from 37+/-12-65+/-8 after 15 days of treatment (P< 0.0001 by one-way ANOVA).

CONCLUSIONS

The immunodominance pattern of IgG epitopes recognized on wasp venom antigens by sera from wasp allergic patients changes soon after initiating rush VIT. Further studies will indicate whether, instead of measuring IgG titres, this marked change could be used as the basis of a new test for monitoring the outcome of VIT.

Characteristics of a developmental arrestant in the venom of the ectoparasitoid wasp Euplectrus comstockii

Parasitic Hymenoptera regulate their hosts in order to provide a suitable source of nutrition and dwelling for their offspring. Few regulatory factors known to cause a specific effect on the host have been structurally characterized. The larval ectoparasitoid Euplectrus comstockii Howard (Hymenoptera: Eulophidae) arrests larval-larval ecdysis in its lepidopteran hosts. Prior to oviposition, the female wasp inject a venom into the hemocoel of the host and that venom alone is effective in causing the arrestment. A venom gland-reservoir structure connected to the lower reproductive tract of the wasp contains a complex mixture of proteins. There are no obvious similarities among the electrophoretic banding pattern (native or denatured) for venom proteins of E comstockii and several other parasitic hymenopteran species. Venomous protein, separated by electrophoretic techniques, with a native mol. wt of c. 66,000, was capable of arresting larval-larval ecdysis in 4th instar larvae of Trichoplusia ni (Lepidoptera: Noctuidae). Nanogram quantities of the protein were sufficient to cause arrestment. The activity of the protein was sensitive to temperature, pH, organic solvent, and protease.

Increased responsiveness and decreased expression of G proteins in deoxycorticosterone hypertension

Deoxycorticosterone-salt (DOCA-salt) hypertension is characterized by elevated vasoconstriction to agonists that stimulate G protein-mediated activation of phospholipase C. However, the mechanisms responsible for the augmented responsiveness are unknown. This study tested the hypothesis that this augmented vascular responsiveness is due to elevated content of G(alpha)q, the G protein alpha-subunit that activates phospholipase C. Thoracic aortae from DOCA-salt hypertensive rats (systolic blood pressure 183 +/- 7 mm Hg) and normotensive controls (systolic blood pressure 115 +/- 2 mm Hg) were homogenized and G protein content determined. Western analysis revealed that G(alpha)i content was decreased in DOCA compared with control rats (1364 +/- 196 versus 2343 +/- 188 densitometry units, P < or = .05) with no differences observed for G(alpha)q or G(alpha)s. In addition, contractile responses in denuded femoral artery strips revealed a significant decrease in EC50 values in DOCA arteries to all of the agonists examined: aluminum fluoride (DOCA = 1.42, control = 2.34 mmol/L), mastoparan (DOCA = 0.51, control = 35 micromol/L), phenylephrine (DOCA = 0.08, control = 0.53 micromol/L), and serotonin (DOCA = 0.014, control = 0.04 micromol/L, EC20 values). Finally, arteries from DOCA rats contracted with aluminum fluoride had increased sensitivity to G protein antagonists but not to a phospholipase C inhibitor. The enhanced contractile responsiveness in the DOCA arteries may be mediated in part through decreased G(alpha)i levels. However, it is not caused by increased concentrations of G(alpha)q in the cell membrane or by increased phospholipase C sensitivity, and the increased constrictor response to G protein stimulators of phospholipase C appears to depend primarily on increased G protein sensitivity.

Rapid venom immunotherapy is safe for routine use in the treatment of patients with Hymenoptera anaphylaxis

BACKGROUND

Rapid venom immunotherapy regimens have been developed to provide safe protection to individuals who have experienced Hymenoptera anaphylaxis by administering greater than 50 micrograms of venom over two to three hours on treatment day 1. A rapid venom immunotherapy protocol which consisted of administration of a cumulative dose of 58.55 micrograms of each venom on treatment day 1 followed by an accelerated build-up over 3 weeks to a final maintenance dose of 100 micrograms per venom was developed by our group in 1984.

OBJECTIVE

We report our 10-year cumulative experience with this rapid venom immunotherapy regimen.

METHODS

Seventy-seven venom-allergic patients received a cumulative dose of 58.55 micrograms per venom on treatment day 1 in an ambulatory care setting. Rapid venom immunotherapy was assessed for safety. A cost analysis was performed to compare rapid venom immunotherapy to a modified rush immunotherapy regimen.

RESULTS

Four patients (5.2%), experienced mild systemic reactions consisting of diffuse urticaria on day 1. Treatment was otherwise well tolerated. Resting events occurred in 21 patients, a mean number of 12 months (range: 3 days to 48 months) after treatment, without systemic reactions.

CONCLUSIONS

This experience confirms that rapid venom immunotherapy is safe to administer in an ambulatory setting and should be considered especially for patients during the stinging insect season when rapid protection is required.

Mastoparan reduces the supraspinal analgesia mediated by mu/delta-opioid receptors in mice

Intracerebroventricular (i.c.v.) administration of the venom peptide, mastoparan, to mice decreased to a limited extent opioid-induced supraspinal analgesia in a non-competitive fashion. The mu-opioid receptor agonists, [D-Ala2,N-MePhe4,Gly-ol5]-enkephalin (DAMGO) and morphine, the mu/delta-opioid receptor ligands, human beta-endorphin-(1-31) and [D-Ala2,D-Leu5]-enkephalin (DADLE), and the selective ligands of delta-opioid receptors, [D-Pen2,5]enkephalin (DPDPE) and [D-Ala2]deltorphin II, showed an impaired analgesic effect in mice given mastoparan. Mastoparan diminished the analgesic activity of DPDPE and [D-Ala2]deltorphin II to the same extent as observed after giving the delta-opioid receptor-selective antagonist, ICI 174864. The mu-opioid receptor-mediated analgesia that remained after mastoparan was abolished in the presence of the opioid antagonist, naloxone. Mastoparan after binding to Gi alpha/Go alpha subunits could block opioid antinociception. The existence of a class of G protein functionally coupled to mu-opioid receptors, but resistant to the effect of mastoparan is suggested.

Safety and efficacy of a 12-week maintenance interval in patients treated with Hymenoptera venom immunotherapy

It is currently recommended to administer a maintenance dose of 100 micrograms of venom at 4-6 week intervals for Hymenoptera venom immunotherapy (VIT). Because the optimal duration of therapy is not known, we decided to progressively prolong the interval between maintenance injections instead of accepting the risk of anaphylactic reactions when VIT is discontinued after a predetermined period. We report here on the results of a first phase of this interval extension programme, covering the gradual increase of the interval from 1-12 weeks over 19 months in 178 patients. A 12-week interval maintenance VIT could be achieved in 117/128 (91%) of yellow jacket venom (YJV) and in 35/50 (70%) of honeybee venom (HBV) allergic patients. At the time of the interview these 152 patients had been treated with 12-weekly 100 microgram venom injections for an average period of 2 years without any untoward reaction to VIT. During this period 48 YJV allergy sufferers experienced 77 field re-stings without systemic reaction (SR), and 17 HBV allergic subjects were restung at least 213 times in total, with one patient developing a very large local reaction and one a mild systemic reaction. In 26 of the 178 patients the interval of 12 weeks was not reached for various reasons, with a higher failure rate among the HBV allergic patients. Most Hymenoptera venom allergic patients can thus be safely and effectively treated with 12-weekly injections of 100 micrograms venom.

The Hymenoptera venom study. III: Safety of venom immunotherapy

One thousand four hundred ten (44%) of the 3236 subjects in the Hymenoptera venom study accepted venom immunotherapy (VIT). Time to maintenance averaged 95 days, and the largest number achieved maintenance (147 subjects, 10.4%) at day 56. Ninety-two percent of the treated subjects achieved maintenance, and 84% continued therapy, most subjects (91%) until the study was terminated. One hundred seventy-one subjects (12%) experienced 327 treatment systemic reactions (Srs). The incidence of pruritus and angioedema/urticaria was similar with mild, moderate, or severe SRs. The SR severity did not correlate with the severity of the most recent sting before entry into the Hymenoptera-venom study, the most severe historical sting SR, the most severe SR during venom skin tests, the total dose of venom, the degree of skin test reactivity, or the lowest concentration yielding a positive skin test. Most SRs occurred between 1 and 50 micrograms and at maintenance; honeybee or wasp venoms were most likely to produce SR. This study, the largest of its kind with the use of standardized extracts, demonstrates (1) that there was good compliance, (2) that various historical and diagnostic criteria did not predict SRs to VIT, (3) that SRs to VIT were most likely to occur between 1 and 50 micrograms and at maintenance, (4) that honeybee or wasp venoms were most likely to produce an SR, and (5) that VIT is relatively safe.

Mastoparan, a wasp venom, activates platelets via pertussis toxin-sensitive GTP-binding proteins

Mastoparan induced limited release of serotonin from intact human platelets, while neither intracellular calcium ion elevation nor arachidonic acid mobilization was observed. Cytolysis induced by mastoparan was negligible in the concentration range that induced serotonin release. In digitonin-permeabilized cells, mastoparan induced Ca(++)-independent release of serotonin and Ca(++)-dependent arachidonic acid release. Both serotonin release and arachidonic acid release were reduced by pertussis toxin, suggesting that platelet activation induced by mastoparan is mediated by GTP-binding proteins.