Cytotoxic effects of Chartergellus communis wasp venom peptide against melanoma cells

Cancer is a huge public health problem being one of the main causes of death globally. Specifically, melanoma is one of the most threatening cancer types due to the metastatic capacity, treatment resistance and mortality rates. It is evident the urgent need for research on new agents with pharmacological potential for cancer treatment, in order to develop new cancer therapeutic strategies and overcome drug resistance. The present work investigated the anti-tumoral potential of Chartergellus-CP1 peptide, isolated from Chartergellus communis wasp venom on human melanoma cell lines with different pigmentation degrees, namely the amelanotic cell line A375 and pigmented cell line MNT-1. Chartergellus-CP1 induced selective cytotoxicity to melanoma cell lines when compared to the lower induced cytotoxicity towards to nontumorigenic keratinocytes. Chartergellus-CP1 peptide induced apoptosis in both melanoma cell lines, cell cycle impairment in amelanotic A375 cells and intracellular ROS increase in pigmented MNT-1 cells. The amelanotic A375 cell line showed higher sensitivity to the peptide than the pigmented cell line MNT-1. From our knowledge, this is the first study reporting the cytotoxic effects of Chartergellus-CP1 on melanoma cells.

The therapeutic effect of wasp venom (Vespa magnifica, Smith) and its effective part on rheumatoid arthritis fibroblast-like synoviocytes through modulating inflammation, redox homeostasis and ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Rheumatoid arthritis (RA) is a chronic inflammatory disease that is related to the aberrant proliferation of fibroblast-like synoviocytes (FLS). Wasp venom (WV, Vespa magnifica, Smith), an insect secretion, has been used to treat RA in Chinese Jingpo national minority's ancient prescription. However, the potential mechanisms haven't been clarified.

AIM OF THE STUDY

The purposes of this paper were two-fold. First, to investigate which was the best anti-RA effective part of WV-I (molecular weight less than 3 kDa), WV-II (molecular weight 3-10 kDa) and WV-III (molecular weight more than 10 kDa) that were separated from WV. Second, to explore the underlying molecular mechanism of WV and WV-II that was best effective part in RA.

MATERIALS AND METHODS

The wasps were electrically stimulated and the secretions were collected. WV-I, WV-II and WV-III were acquired by ultracentrifuge method according to molecular weight. Next, WV, WV-I, WV-II and WV-III were identified by HPLC. Functional annotation and pathway analysis of WV used to bioinformatics analysis. RNA-seq analyses were constructed to identify differentially expressed genes (DEGs). GO and KEGG pathway analyses were performed by Metascape database. STRING was used to analyze the PPI network from DEGs. Next, PPI network was visualized using Cytoscape that based on MCODE. The pivotal genes of PPI network and MCODE analysis were verified by qRT-PCR. Subsequently, MH7A cells were performed by MTT assay to evaluate the ability of inhibiting cell proliferation. Luciferase activity assay was conducted in HepG2/STAT1 or HepG2/STAT3 cells to assess STAT1/3 sensitivity of WV, WV-I, WV-II and WV-III. Additionally, interleukin (IL)-1β and IL-6 expression levels were detected by ELISA kits. Intracellular thioredoxin reductase (TrxR) enzyme was evaluated by TrxR activity assay kit. ROS levels, lipid ROS levels and Mitochondrial membrane potential (MMP) were assessed by fluorescence probe. Cell apoptosis and MMP were measured by using flow cytometry. Furthermore, the key proteins of JAK/STAT signaling pathway, protein levels of TrxR and glutathione peroxidase 4 axis (GPX4) were examined by Western blotting assay.

RESULTS

RNA-sequencing analysis of WV displayed be related to oxidation-reduction, inflammation and apoptosis. The data displayed that WV, WV-II and WV-III inhibited significantly cells proliferation in human MH7A cell line compared to WV-I treatment group, but WV-III had no significant suppressive effect on luciferase activity of STAT3 compared with IL-6-induced group. Combined with earlier reports that WV-III contained major allergens, we selected WV and WV-II further to study the mechanism of anti-RA. In addition, WV and WV-II decreased the level of IL-1β and IL-6 in TNF-α-induced MH7A cells via inactivating of JAK/STAT signaling pathway. On the other hand, WV and WV-II down-regulated the TrxR activity to produce ROS and induce cell apoptosis. Furthermore, WV and WV-II could accumulate lipid ROS to induce GPX4-mediated ferroptosis.

CONCLUSIONS

Taken together, the experimental results revealed that WV and WV-II were potential therapeutic agents for RA through modulating JAK/STAT signaling pathways, redox homeostasis and ferroptosis in MH7A cells. Of note, WV-II was an effective part and the predominant active monomer in WV-II will be further explored in the future.

Regulatory T cell and cytokine changes in children undergoing 3 days rush venom immunotherapy

BACKGROUND

Rush venom immunotherapy (VIT) is the recommended treatment for patients with Hymenoptera anaphylaxis. Specific data regarding regulatory T cell and cytokine changes in children receiving rush VIT are sparse.

OBJECTIVE

To study the changing of CD4+CD25+FOXP3+ regulatory T cells (Treg) and serum cytokines in children undergoing 3 days rush VIT.

METHODS

Children younger than 15 years with systemic reaction to Hymenoptera who had evidence of IgE sensitization to Hymenoptera were enrolled for 3 days rush VIT. Peripheral blood CD4+CD25+FOXP3+ Treg and serum IL-4, IL5, IL-13, IFN-γ, and IL-10 were measured at baseline before rush VIT, achieving maintenance dose, 6 months, and 12 months after reaching maintenance dose. Specific IgE to Hymenoptera was measured at baseline and 12 months after VIT.

RESULTS

A total of 15 children (11 boys and 4 girls) aged 6-15 years (mean age, 10 years) were enrolled. Four children were allergic to bee and 11 children were allergic to Vespid. The levels of CD4+CD25+FOXP3+ Treg were significantly increased at 6 months after maintenance dose compared with baseline (6.58% VS 4.01%, p = 0.001). Serum IL-13, IFN-γ, and IL-10 levels did not change significantly from baseline. However, there was a significant reduction of IL-4 in the serum at 12 months after MN when compared to the baseline levels. The systemic reaction requiring epinephrine intramuscular injection occurred only in 1 case who was on Vespid venoms rush VIT.

CONCLUSIONS

Three days rush VIT provide acceptable systemic reaction and able to increase the number of CD4+CD25+FOXP3+ Treg in children.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

An Introduction to the Toxins Special Issue on "Bee and Wasp Venoms: Biological Characteristics and Therapeutic Application"

n/a.

[Intolerance of specific immunotherapy with Hymenoptera venom: jumping the hurdle with omalizumab]

Specific immunotherapy is a very effective and well-tolerated therapeutic option in patients with Hymenoptera venom allergy. Many patients can be successfully treated, and severe side-effects are rarely seen. In most cases local swelling of the injection site is noticed, whereas systemic reactions are uncommon. No reliable biomarkers to prove the positive response to the specific immunotherapy have been validated. But on the other hand the failure of the venom immunotherapy can be verified by performing a sting challenge test; in this case the maintenance dose of the venom immunotherapy has to be increased and the sting challenge test has to be repeated. This approach works well most of the patients. In rare cases severe anaphylactic reactions occur during the initiation of the venom immunotherapy due to individual risk factors. While in the past this necessitated discontinuation of the specific immunotherapy, the current situation has remarkably changed. Since the IgE-antibody omalizumab has been licensed for different indications, a new therapeutic option is available. We have employed this approach since 2005. We share our own practical experience as well as recent data, presenting a management approach for Hymenoptera venom allergy in high-risk patients.

Three valuable peptides from bee and wasp venoms for therapeutic and biotechnological use: melittin, apamin and mastoparan

While knowledge of the composition and mode of action of bee and wasp venoms dates back 50 years, the therapeutic value of these toxins remains relatively unexploded. The properties of these venoms are now being studied with the aim to design and develop new therapeutic drugs. Far from evaluating the extensive number of monographs, journals and books related to bee and wasp venoms and the therapeutic effect of these toxins in numerous diseases, the following review focuses on the three most characterized peptides, namely melittin, apamin, and mastoparan. Here, we update information related to these compounds from the perspective of applied science and discuss their potential therapeutic and biotechnological applications in biomedicine.

Two cases of elevated tryptase in abdominal aortic aneurysm

INTRODUCTION

From the literature, patients with a history of anaphylaxis to hymenoptera venom and positive specific IgE have shown a correlation between elevated tryptase levels and two clinical situations: systemic mastocytosis and an increased risk of reactions to venom immunotherapy or hymenoptera sting. Other clinical scenarios could explain elevated tryptase levels.

MATERIAL AND METHODS

A 67 year old male (P1) and a 77 year old male (P2) were evaluated for previous severe anaphylaxis to hymenoptera sting. They underwent standard diagnostic work-up for hymenoptera venom allergy. Having found elevated tryptase levels, these were followed by a bone marrow biopsy to rule out systemic mastocytosis.

RESULTS

P1: specific IgE and skin tests were positive for Vespula species; tryptase 52.8 ng/ml; P2: specific IgE and skin tests were positive for Vespa cabro and tryptase 153 ng/ml. Bone marrow biopsy results were negative for mastocytosis. We carried out magnetic resonance imaging, in P1 to better characterize the severe osteoporosis and in P2 because during physical examination a pulsating mass had been identified in the mesogastrium, and an aneurysm of the abdominal aorta which required surgical intervention in both patients was detected. Eight months after surgery, tryptase levels had diminished significantly (P1: 11.6 ng/ml and P2: 14.5 ng/ml).

DISCUSSION

The elevated tryptase levels were correlated to abdominal aneurysm in both patients. In fact, post-surgery tryptase levels dramatically decreased. These two cases demonstrate that high tryptase levels in subjects with a history of hymenoptera venom anaphylaxis can be associated to undiagnosed aneurysmatic disease.

Impact of Hymenoptera venom allergy and the effects of specific venom immunotherapy on mast cell metabolites in sensitized children

INTRODUCTION AND OBJECTIVE

Mast cells (MC) are effector cells during severe systemic reactions (SR) to Hymenoptera stings. Venom specific immunotherapy (VIT) is the treatment of choice for prevention of SR to stings. Tryptase and prostaglandin D₂ metabolites (PGD₂) are the markers of MC activation. The study design was to 1. compare baseline values of serum tryptase concentration (BST) and PGD₂ metabolites in children with/without venom sensitization, 2. to evaluate an influence of rush VIT on MC markers in treated children.

MATERIALS AND METHODS

Sensitized group: 25 children with SR to Hymenoptera sting.

CONTROL GROUP

19 healthy children. Active treatment: 5-day-rush-VIT. BST was evaluated by ImmunoCAP, PGD₂ metabolites in blood and urine by GC-NICI-MS.

RESULTS

The baseline blood levels of MC markers were significantly higher, while urinary concentration of 9α,11β-PGF₂ was significantly lower in the whole group of venom-sensitized children compared to controls. Severity of SR showed negative correlation with urinary PGD₂ metabolites, while positive with plasma 9α,11β-PGF₂ and BST concentration The highest sensitivity was obtained for plasma 9α,11β-PGF₂ whereas the highest specificity for urinary PGD-M.

CONCLUSIONS

In children with IgE-mediated SR to Hymenoptera stings, elevation of baseline values of PGD₂ metabolites in blood is accompanied by decreased excretion of its urinary metabolites. Assessment of stable PGD₂ metabolites might serve as an independent MC marker to identify allergic children. There is an association between urinary PGD₂ metabolites and severity of the SR to Hymenoptera stings.

Safety profile of hymenoptera venom immunotherapy (VIT) in monosensitized patients: lack of new sensitization to nontreated insect venom

BACKGROUND

Venom immunotherapy (VIT) has proven to be efficacious in reducing the severity of anaphylactic reactions following field stings in patients with Hymenoptera venom allergy. Due to sequence homologies in the allergens used in Hymenoptera vaccines, there is concern that immunotherapy could lead to sensitization to allergens to which patients were not previously sensitized. The relevance of such an undesired phenomenon is unclear.

OBJECTIVES

To investigate the incidence of sensitization to Hymenoptera venoms other than those to which the patients were already sensitized and to assess the overall safety profile of VIT in order to compare the risk-benefit ratio in a subpopulation of monosensitized individuals.

METHODS

We performed a retrospective analysis of specific immunoglobulin E (sIgE) levels in patients with no prior detectable sIgE to Hymenoptera venom other than the one for which they received VIT. We assessed the safety profile of VIT using serological and clinical parameters.

RESULTS

Of the 56 monosensitized patients who had VIT, 3 (5%) developed sIgE to the other insect with no history of field sting to explain it. This rate was similar to the rate of new sensitization due to field stings during VIT. VIT was well-tolerated and levels of serological markers improved. No patient had a systemic anaphylactic reaction after having been stung by an insect other than the one he/she was desensitized for during follow-up.

CONCLUSION

VIT seems to be safe with respect to clinically significant new sensitizations.

Serum tryptase level is a better predictor of systemic side effects than prostaglandin D2 metabolites during venom immunotherapy in children

OBJECTIVES

We performed a prospective study to analyze mast cell mediators as predictors of systemic adverse reactions during rush venom-specific immunotherapy (VIT) in children.

PATIENTS AND METHODS

Nineteen children aged 5-17 years received VIT with Venomenhal (HALAllergy). We analyzed serum tryptase (CAP, Phadia), plasma prostaglandin (PG) D2 metabolites (9alpha, 11beta-PGF2), and urine PGD2 metabolites (9alpha, 11beta-PGF2, tetranor-PGD-M) using gas chromatography mass spectrometry before and after the rush protocol.

RESULTS

Three boys with high baseline serum tryptase values (>7.76 g/L) (P < .001) and low 9alpha, 11beta-PGF2 concentrations developed grade III systemic adverse reactions during VIT. Baseline serum tryptase was lowest in children who had a Mueller grade II reaction (1.93 [0.36]) before VIT and highest in children with a Mueller grade III reaction (6.31 [4.80]) (P = .029). Repeated measures analysis of variance confirmed that, in children who developed systemic adverse reactions during VIT, serum tryptase was higher both before and after desensitization and increased significantly following the procedure. Analysis of PGD2 metabolites in the prediction of systemic adverse reactions during VIT was inadequate (sensitivity 67% and specificity 0.53%), whilst prediction based on serum tryptase was accurate.

CONCLUSIONS

In children with severe systemic adverse reactions to Hymenoptera sting, the evaluation of baseline tryptase levels should be a standard procedure. Children with Apis mellifera venom allergy and baseline tryptase levels higher than 7.75 g/L are at risk of anaphylaxis during buildup. Lower baseline values of plasma and urinary PGD2 metabolite concentration in patients with systemic adverse reaction during VIT suggest that prostaglandin catabolism is altered.

Alternating Polistes-Vespula venom immunotherapy: a therapeutic strategy to resolve a diagnostic deficiency

BACKGROUND

In Mediterranean regions, double sensitization to Polistes and Vespula species is frequent in patients reacting to an unidentified wasp sting. Since both genera are present, it is often difficult to determine which insect is responsible and, consequently, select venom for immunotherapy. When a specific diagnosis cannot be made, a new therapeutic strategy should be undertaken.

METHODS

We performed a case-control study in which 37 patients who were allergic to venom from Vespula and Polistes species received a 3-year schedule of alternating immunotherapy. Twenty monosensitized patients (10 to Vespula and 10 to Polistes) received conventional venom immunotherapy (VIT) during the same period. All 57 patients received the same number of injections. The effectiveness of VIT was assessed by means of re-sting, which was performed yearly. Serum specific immunoglobulin (Ig) E and IgG4 were also studied,

RESULTS

All the cases tolerated all the stings. One control patient developed a mild systemic reaction after the first-year Vespula sting but tolerated subsequent re-stings. Both cases and controls reached significant changes in levels of IgE and IgG4 after VIT (P < .04 at minimum). The cases developed a response as expected, although this was less intense than in the control group. In the Polistes control subgroup, sIgE to Polistes decreased to under baseline levels, after a marked initial increase; this decrease was not observed in the Vespula subgroup.

CONCLUSION

An alternating VIT strategy is appropriate and provides protection to patients sensitized to Vespula and Polistes.

Early markers for protective mechanisms during rush venom immunotherapy

BACKGROUND

Allergen-specific venom immunotherapy (VIT) represents the only rational-based option to treat allergic sensitizations against bee and wasp venom. So far, there is not much knowledge about early induction of protective and tolerogenic pathways during VIT.

OBJECTIVES

To identify the earliest markers for protective mechanisms against allergic reactions in the peripheral blood during the build-up phase of VIT.

METHODS

PBMC and monocytes were isolated, and serum samples were taken before and during a five day build-up phase from 65 hymenoptera venom allergic patients. Expression level of tolerogenic markers was analyzed on mRNA and protein level. Serum levels of different soluble tolerogenic factors were measured.

RESULTS

We observed significantly enhanced tryptophan degradation, elevated ILT4 expression of monocytes as well as IL-10 production of CD3(+) T cells only a few hours after the first injection on day 1, followed by increased IL-10 serum levels, monocyte apoptosis and elevated intracellular cAMP levels of monocytes on day 3 combined with a higher ILT3 protein expression and IL-10 secretion of monocytes on day 5.

CONCLUSION

From these data, we conclude that tryptophan depletion, ILT3/4-mediated inhibition, higher IL-10 production as well as intracellular cAMP might contribute to early induction of protective mechanisms against allergic reactions during the build-up phase of VIT.

Specific immunotherapy using Hymenoptera venom: systematic review

CONTEXT AND OBJECTIVE

The only effective treatment for patients who have severe reactions after Hymenoptera stings is venom immunotherapy. The aim of this study was to review the literature to assess the effects of venom immunotherapy among patients presenting severe reactions after Hymenoptera stings.

DESIGN AND SETTING

Randomized controlled trials in the worldwide literature were reviewed. The manuscript was produced in the Discipline of Allergy and Clinical Immunology, Universidade de São Paulo (USP).

METHODS

Randomized controlled trials involving venom immunotherapy versus placebo or only patient follow-up were evaluated. The risk of systemic reactions after specific immunotherapy was evaluated by calculating odds ratios (OR) and their 95% confidence intervals.

RESULTS

2,273 abstracts were identified by the keywords search. Only four studies were included in this review. The chi-square test for heterogeneity showed that two studies were homogeneous and could be included in a meta-analysis. By combining the two studies, the odds ratio became significant: 0.29 (0.10-0.87). However, analysis on the severity of the reactions after immunotherapy showed that the benefits may not be so significant because the reactions were mostly similar to or milder than the original reaction.

CONCLUSIONS

Specific immunotherapy should be recommended for adults and children with moderate to severe reactions, but there is no need to prescribe it for children with skin reactions alone, especially if the exposure is very sporadic. On the other hand, the risk-benefit relation should always be assessed in each case.

Immunotherapy with wasp venom is accompanied by wide-ranging immune responses that need further exploration

Immunotherapy with wasp allergen leads to a variety of specific immunological changes. It is unknown, however, whether unspecific effects also occur, and which parameter shifts might indicate treatment success. Therefore, data of patients who had completed immunotherapy with wasp venom were analysed retrospectively for a change in the following parameters after therapy: threshold of skin tests with wasp venom, total and specific serum IgE, specific serum IgG and IgG4, and binding of IgE and IgG4 to major wasp venom allergens. Reactions to field stings were explored. A significant increase in the skin test threshold and a significant decrease in total serum IgE, specific serum IgE and major wasp allergens binding IgE were found. Concentrations of specific serum IgG and IgG4 increased. Patients with corresponding changes in at least three specific parameters did not report severe reactions to verified field stings after therapy. The marked decrease in total serum IgE indicates that wasp immunotherapy has wide-ranging immunological effects, and it appears reasonable to check combinations of several parameters for treatment control.

Long-term efficacy of venom immunotherapy

BACKGROUND

The long-term efficacy of venom immunotherapy (VIT) in patients who either prematurely discontinue VIT or who experience subsequent stings after discontinuation of VIT remains uncertain.

OBJECTIVE

To survey sting reaction patterns in patients who had previously discontinued VIT.

METHODS

Patients who had received VIT between January 1, 1984, and December 31, 2004 were sent a questionnaire inquiring whether they had been stung by an insect to which the VIT had been directed. Symptoms that developed were assessed. The patients were subsequently contacted by telephone to clarify their responses.

RESULTS

Of 227 patients who responded to the questionnaire, 181 (79.7%) received VIT for more than 3 years; 100 of these 181 patients (55.2%) were stung after discontinuing VIT. At the time of the first sting after stopping VIT, 92 patients had a local reaction and 8 had a systemic reaction. Of 40 patients who were stung more than once after ending VIT, 7 (17.5%) experienced reactions of greater severity with the subsequent stings. All the patients reported that their reactions after ending VIT were milder than before treatment. The likelihood of systemic reactions to stings was almost identical in patients treated for either longer or shorter than 3 years with VIT.

CONCLUSIONS

In most patients, VIT provides long-term protection from severe systemic reactions. Risk of systemic reactions increases with subsequent stings after ending VIT. All the patients reported that symptoms experienced with stings after stopping VIT were milder than symptoms before VIT.

Cargo-dependent cytotoxicity and delivery efficacy of cell-penetrating peptides: a comparative study

The use of CPPs (cell-penetrating peptides) as delivery vectors for bioactive molecules has been an emerging field since 1994 when the first CPP, penetratin, was discovered. Since then, several CPPs, including the widely used Tat (transactivator of transcription) peptide, have been developed and utilized to translocate a wide range of compounds across the plasma membrane of cells both in vivo and in vitro. Although the field has emerged as a possible future candidate for drug delivery, little attention has been given to the potential toxic side effects that these peptides might exhibit in cargo delivery. Also, no comprehensive study has been performed to evaluate the relative efficacy of single CPPs to convey different cargos. Therefore we selected three of the major CPPs, penetratin, Tat and transportan 10, and evaluated their ability to deliver commonly used cargos, including fluoresceinyl moiety, double-stranded DNA and proteins (i.e. avidin and streptavidin), and studied their effect on membrane integrity and cell viability. Our results demonstrate the unfeasibility to use the translocation efficacy of fluorescein moiety as a gauge for CPP efficiency, since the delivery properties are dependent on the cargo used. Furthermore, and no less importantly, the toxicity of CPPs depends heavily on peptide concentration, cargo molecule and coupling strategy.

[Immunotherapy against hymenoptera venom: report of ten patients]

BACKGROUND

Immunotherapy can be used to treat allergic reactions to insect stings, specially bees and wasps.

AIM

To report the experience with immunotherapy with aqueous extracts of hymenoptera venoms (bees and wasps).

MATERIAL AND METHODS

Ten patients aged 6 to 58 years were treated in an allergy center of a University Clinical Hospital. The medical indication for this treatment was, in all patients, anaphylactic reactions after hymenoptera stings. Immunotherapy was carried out using standardized vaccines (Aqueous extracts Venomvac LETI, Spain), applied in a traditional protocol, with subcutaneous injections. This protocol had two phases: a buildup phase (between weeks 1 and 13) and a monthly maintenance phase, from the 13th week. The monthly maintenance dose was 100 fig of hymenoptera specific venom extract.

RESULTS

Six patients had adverse reactions of different severity, during the treatment protocols and all had a good response to immediate therapeutic measures. After these events, they followed the protocol without problems. Two patients, treated with bee vaccines, suffered an accidental bee sting during the maintenance phase and they developed only local reactions.

CONCLUSIONS

The lack of adverse reactions to bee stings in these two patients indicates the acquisition of clinical tolerance.

Premedication with Montelukast Reduces Local Reactions of Allergen Immunotherapy

BACKGROUND

Local reactions (LRs) are a very frequent side effect of specific immunotherapy with allergens and can impair patients' adherence. Antihistamine pretreatment--originally introduced as a safety measure to reduce anaphylactic side effects--has been the only treatment option for LRs so far, although these swellings usually do not appear immediately but after hours. We were interested whether pretreatment with the leukotriene antagonist montelukast would be better suited for preventing those reactions than pretreatment with the antihistamine desloratadine.

METHODS

Fifteen patients with a history of severe anaphylactic reactions to hymenoptera stings were enrolled into a prospective, double-blind, randomized, placebo-controlled pilot study. We selected a rush immunotherapy protocol consisting of 19 injections of hymenoptera venom administered over 5 consecutive days, where the majority is developing LRs, and counted the number of injections until an LR of >3 cm occurred. The patients were randomized to 3 treatment groups: premedication with placebo, 10 mg montelukast and 5 mg of the antihistamine desloratadine.

RESULTS

Compared with placebo, the occurrence of LRs (>3 cm) was significantly delayed by montelukast (p < 0.01, analysis of variance) but not by desloratadine (p = 0.19). The difference between montelukast and desloratadine was close to significant (p = 0.054). Itching, recorded on a scale from 0 to 5, did not differ between the 3 groups.

CONCLUSION

Montelukast can be useful in the prevention of LRs after specific immunotherapy.

Evaluation of the IgE cross-reactions among vespid venoms. A possible approach for the choice of immunotherapy

BACKGROUND

Hymenoptera venom allergy can be effectively cured with specific immunotherapy, thus the correct identification of the allergen is essential. In the case of multiple skin and serum positivities it is important to know if a cross-reaction among venoms is present. We studied by CAP-inhibition assays the degree of cross-reactivity between Vespula vulgaris and Polistes dominulus.

METHODS

Serum samples were obtained from consecutive patients with a clinical history of grade III-IV reactions to hymenoptera sting and with nondiscriminative skin/CAP positivity to both Vespula and Polistes. Inhibition assays were carried out with a CAP method, incubating the sera separately with both venoms and subsequently measuring the specific immunoglobulin E (IgE) to venoms themselves.

RESULTS

Forty-five patients (33 male, mean age 40 years, age range 12-74, total serum IgE 242 +/- 168 kU/l) were included. Their specific IgE to Vespula and Polistes were 12.03 +/- 5.70 kU/l and 10.7 +/- 2.0 kU/l (P = NS), respectively. At the CAP-inhibition assays, in 25 patients a >75% heterologous inhibition by P. dominulus venom against V. vulgaris-specific IgE was found. In six subjects V. vulgaris venom effectively inhibited the P. dominulus-specific IgE. In the remaining 14 cases the CAP-inhibition test provided intermediate and not discriminative results.

CONCLUSION

In 31/45 patients, the double sensitizations to venoms were probably the result of cross-reactions and the CAP-inhibition allowed identifying the true double sensitizations. This approach may be helpful for the correct prescription of immunotherapy in the case of V. vulgaris and P. dominulus double positivity.

Changes in intracellular cyclic adenosine monophosphate levels in peripheral blood leukocytes during immunotherapy with vespid venom

BACKGROUND

The allergen-induced release of mediators from basophils is known to be decreased after rush venom immunotherapy (VIT) compared with pretreatment values. A rise in the intracellular cyclic adenosine monophosphate (cAMP) level is known to inhibit mediator release.

OBJECTIVES

To determine changes in cAMP levels in peripheral blood leukocytes (PBLs) during rush VIT and to evaluate their relation to allergen-specific reactivity of basophils.

METHODS

Ten patients allergic to vespid venom (VV) were investigated before rush VIT and after reaching the maintenance dose. Five VV-allergic patients not undergoing VIT served as controls. Patients' PBLs were incubated with VV, and allergen-induced histamine and leukotriene release from basophils was measured. Levels of cAMP were determined in PBLs and in plasma.

RESULTS

Immediately after rush VIT, VV-induced histamine release (P = .04) and VV-induced leukotriene release (P = .01) were significantly reduced. Intracellular cAMP levels increased significantly (P = .047). However, 6 months after VIT, mediator responses in basophils were comparable with pre-VIT values. No significant changes were found in the control group.

CONCLUSIONS

An increase in intracellular cAMP levels might account for the decreased reactivity of basophils to allergen after 1 week of VIT. However, similar to the decreased mediator release after 1 week of VIT, this is not a long-term effect as values returned to baseline after 6 months.

Ultrarush venom desensitization after systemic reactions during conventional venom immunotherapy

BACKGROUND

Rush and ultrarush venom immunotherapy (VIT) protocols are safe and effective in patients with Hymenoptera hypersensitivity. However, these protocols have typically been used instead of conventional VIT and not in patients who have experienced adverse reactions during conventional VIT. To date, there are no reports of using an ultrarush VIT protocol to desensitize patients with a history of severe systemic reactions during conventional VIT.

OBJECTIVE

To determine whether ultrarush VIT can be safely administered to a high-risk patient with a history of severe systemic reactions to conventional VIT.

METHODS

Premedication with 40 mg of prednisone, 180 mg of fexofenadine, and 150 mg of ranitidine orally twice daily was initiated. The patient received VIT to mixed vespid and wasp in a medical intensive care unit via a 13-step buildup on day 1 followed by a 2-step buildup on day 2. Immunotherapy was begun with a dose of 0.005 microg of mixed vespid and 0.002 microg of wasp venom and achieved a total dose of 300 microg of mixed vespid and 100 microg of wasp venom.

RESULTS

The patient tolerated the procedure with minimal adverse effects. She subsequently received maintenance dosing in the outpatient clinic weekly for 4 weeks and bimonthly for 8 weeks, and she continues monthly maintenance VIT.

CONCLUSIONS

We report the first successful use of ultrarush VIT in a high-risk patient with a history of severe systemic reactions during conventional VIT. This protocol should be considered in patients with a history of allergy to vespids or wasps who require VIT but cannot reach a maintenance dose with conventional VIT owing to systemic reactions.

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.

The safety of allergen immunotherapy (IT) in Turkey

Allergen immunotherapy (IT) has encouraging therapeutic outcomes but its safety is still being questioned because of possible severe systemic reactions. The aim of this study was to determine the frequency of systemic reactions (SR), and to identify their correlation with the characteristics of therapy, such as allergen composition and IT schedule, and diagnosis. We analyzed the data of 126 patients who received IT between 2000-2003, and suffered from respiratory allergy or hymenoptera venom anaphylaxis. IT was given by rush, clustered or conventional schedules. The standardized allergen extracts used were grass pollen, house dust mite and hymenoptera venom in 88, 18 and 20 patients, respectively. None of the patients received premedication. A total 4705 injections were administered. One hundred and twenty-three adverse events (AE) (2.6% per injection) were documented in 46 patients. Sixty-one of them were SRs (1.3% SRs per injection) and they were seen in 28 patients. Asthmatics had more tendency to SRs (p=0.05). Rush (1.8%) and clustered (2.8%) IT protocols were associated with a higher rate of SRs (per injection) when compared to conventional schedule (0.9%) (rush vs conventional; p=0.013, clustered vs conventional; p=0.001). The majority of SRs corresponded to grade 3 (49%). Forty-nine (80%) of the 61 SRs were observed during the build-up phase, and mostly with pollen extracts (75.5%). Patients showed more severe SRs during the build-up phase (p<0.05). Twenty-six (42.6%) of the SRs were immediate, whereas 35 (57.4%) SRs appeared within 2 hours. Delayed SRs were significantly more frequent in polysensitized patients when compared to monosensitized subjects (p=0.018). Our data indicate that rapid IT regimens and the presence of asthma represent a greater risk for SR development. Since the late SRs occur as frequently as the early ones, we suggest a longer waiting period beyond 30 minutes, especially in polysensitized and asthmatic patients.

Rush hymenoptera venom immunotherapy is efficacious and safe

BACKGROUND

Although rapid venom immunotherapy (VIT) protocols have been shown to be safe and effective, this issue has not yet been clarified in Turkey.

OBJECTIVE

The aim of this study was to evaluate the side effects of rush VIT as well as early clinical and immunological responses in patients with a venom allergy.

METHODS

Eighteen patients who had a history of severe systemic reactions after Hymenoptera sting were included in the study. The diagnosis was made on the basis of positive skin test reactivity and the presence of specific IgE in serum to either bee or vespid venoms. Fourteen patients underwent an average 7-day rush VIT regimen under careful monitoring in our clinic. Among them 7 patients were treated with Vespula species and 7 with Apis mellifera venom extracts. Four patients were followed up as a control group. Skin test response, specific IgE and IgG4 levels were determined before and after a year of VIT. Local and systemic reactions due to injections were monitored during the induction and maintenance phases of VIT.

RESULTS

Specific IgG4 levels significantly increased after 1 year compared with levels before VIT (mean concentration before and after; 13.04 vs 21.85 mg/L, respectively; P < .05) whereas specific IgE levels did not change (11.54 vs. 13.32 kU/L). No significant differences were observed before and after one year of VIT in skin prick (2.34 vs 3.66 mm) and intradermal (0.12-0.11 microg/mL) test reactivities (P > .05). A single patient treated with bee venom developed 4 mild systemic reactions (4/469 injections, 0.85%) during the course of VIT. More local reactions occurred in patients receiving bee venom extract (3.33%) than in those receiving yellow jacket venom (1.33%). Two patients tolerated field stings without reactions.

CONCLUSION

Our experience confirms that rush VIT is safe and has a low systemic reaction. It can be considered for patients requiring rapid protection.

Polymethyleneamine alkaloids of animal origin: II. polyamine neurotoxins

Information on the structure and biological activity of animal alkaloids, polymethyleneamine components of spider and wasp venoms, is considered and systematized. These natural compounds are used for the development and modification of medicines for treating the functional disturbances in the central nervous system of humans.

High sensitivity of basophils predicts side-effects in venom immunotherapy

BACKGROUND

Systemic side-effects of venom immunotherapy (VIT) represent a considerable problem in the treatment of patients allergic to Hymenoptera venom. We examined the hypothesis whether basophil responsiveness might be connected with the adverse reactions to VIT.

METHODS

Basophil surface expression of activation marker CD63 induced by different concentrations of honeybee and wasp venom (0.1 and 1 mug/ml) was measured by flow cytometry in 34 patients with history of systemic anaphylactic reactions to Hymenoptera sting just before rush honeybee or wasp VIT.

RESULTS

Eleven of 34 patients had systemic anaphylactic reaction (Mueller grades I-III) and one patient a large local reaction to VIT. In those 12 patients, median percentage of activated basophils after stimulation with VIT-specific venom in concentration of 0.1 microg/ml was 99% (range: 17-195) of value reached with stimulation with 1 microg/ml. Side-effects occurred in all patients with 0.1/1 ratios over 92% (eight of 12). In contrast, in 22 patients with no side-effects, the median 0.1/1 ratio was 25% (range: 2-92). These concentration-dependent activation ratios were significantly different between the groups with and without side reactions (P < 0.0001). We also show significant positive correlation of the occurrence/clinical grade of the side-effects with individual ratios of CD63 basophil response (r = 0.73, P < 0.0001).

CONCLUSION

The results suggest that increased basophil sensitivity to allergen-specific in vitro stimulation is significantly associated with major side-effects of VIT.

[Safety of rush immunotherapy with Hymenoptera venom]

OBJECTIVES

To determine the incidence and nature of adverse events associated with the induction of rush Hymenoptera venom immunotherapy.

MATERIAL AND METHODS

Between 1998 and 2003, we administered venom immunotherapy to 48 patients allergic to bee or wasp venom, by means of a rush immunotherapy protocol (3 days).

RESULTS

We observed no severe adverse reactions in any patients. 12 patients developed only local reactions at the site of injections that did not required any pharmacological treatment. Two patients experienced mild systemic reactions consisting of diffuse urticaria on day 3. Both adverse reactions were treated with intravenous antihistamines.

CONCLUSIONS

Our experience confirms that rapid venom immunotherapy is safe and should be considered in every case especially for patients during the stinging insect season when a rapid protection is required.

Anticonvulsant effects of the wasp Polybia ignobilis venom on chemically induced seizures and action on GABA and glutamate receptors

Venoms of spiders and wasps are well recognized to present high affinity to the central nervous tissue of many mammalian species. Here we describe the effects of direct exposure of rat (Rattus norvegicus) brains to the crude and denatured venom of the Brazilian social wasp Polybia ignobilis. Lower doses of crude venom injected via intracerebroventricular (i.c.v.) inhibited the exploratory activity of animals, while higher doses provoked severe generalized tonic-clonic seizures, with hind limb extension. The status epilepticus lasted for few minutes leading the animals to respiratory depression and death. In contrast, the denatured venom was anticonvulsant against acute seizures induced by the i.c.v. injection of bicuculline, picrotoxin and kainic acid, but it was ineffective against seizures caused by systemic pentylenetetrazole. Moreover, the [3H]-glutamate binding in membranes from rat brain cortex was inhibited by the denatured venom in lower concentrations than the [3H]-GABA binding. The denatured venom contains free GABA and glutamate (34 and 802 pg/microg of venom, respectively), but they are not the major binding inhibitors. These interactions of venom components with GABA and glutamate receptors could be responsible for the anticonvulsant effects introducing the venom from P. ignobilis as a potential pharmacological source of anticonvulsant drugs.

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.

Continuous immunotherapy for hymenoptera venom allergy using six month intervals

BACKGROUND

Specific immunotherapy for hymenoptera venom allergy (venom immunotherapy [VIT]) is safe and effective. The duration of treatment is still open for discussion because there is no reliable routine test to determine the real risk of serious anaphylactic reactions. This prospective study, which spans more than 25 years, was conducted to ensure unlimited protection through continuous VIT. To reduce workload and cost, the maintenance interval was increased to 6 months without increasing the rate of adverse events. Only patients with continuous follow-up by our service were included in this study.

PATIENTS AND METHODS

VIT was conducted in 176 patients (125 allergic to wasp venom, 20 to bee venom, 31 to both) over a mean of 7.14 years (1.16-25.49). Total and specific IgE were determined on a regular basis.

RESULTS

A total of 162 re-stings were reported. Of these, 154 produced a strictly local reaction, seven produced non-serious reactions and one produced a systemic reaction similar to that produced by the initial sting before VIT. Total and specific IgE diminished during VIT. Substantial adverse effects were rare and never life-threatening. The effects occurred during observation in the ward and were controlled according to the treatment protocol recommended by a German expert consensus meeting on the treatment of anaphylactoid reactions. VIT was terminated in only one patient due to recurrent adverse effects.

CONCLUSION

Continuous VIT at 6-monthly maintenance intervals conferred permanent protection in patients allergic to bee and wasp venoms and was found to be a safe and effective alternative to current standard protocols.

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.

The sting challenge test in Hymenoptera venom allergy: pros and cons

This paper examines the main features of the deliberate sting challenge with regard to the type of insect, the advantages and disadvantages of its use in untreated and treated patients and after discontinuation of specific immunotherapy.

[Clinical and biological surveillance after the cessation of Hymenoptera venom desensitization]

107 patients have discontinued Hymenoptera venom immunotherapy between 1988 and 2000. 31 have been seen again with intradermal tests with IgEs, and 81 responded to a questionnaire. Intradermal reactions and IgEs decrease together significantly during immunotherapy and then persist at low level during three years. Beyond, the number of patients is insufficient. 32 patients were stung by the same Hymenoptera and not had any systemic reaction. However, five have beta blockers, three have IEC and half of the patients don't take precautions to avoid Hymenoptera.

Rush Hymenoptera venom immunotherapy: a safe and practical protocol for high-risk patients

BACKGROUND

Hymenoptera venom immunotherapy in allergic patients is a well-established treatment modality for the prevention of systemic anaphylactic reactions caused by insect stings. A variety of therapy regimens exists, from conventional to rush and ultrarush modalities that operate on continuous or intermittent schedules.

OBJECTIVE

The aim of this study was to report the 8-year experience with our rush venom immunotherapy regimen in predominantly high-risk patients and to compare data on safety and convenience with the results of 26 studies published from 1978 to 2001.

METHODS

One hundred one patients allergic to bee, yellow jacket, or hornet venom were treated with rush Hymenoptera venom immunotherapy. Diagnosis and selection of patients for venom immunotherapy were carried out according to the recommendations of the European Academy of Allergology and Clinical Immunology. We used a 4-day regimen, and the incidence and nature of systemic reactions (SRs) were documented. Fifty-two patients were treated with honeybee venom, and 49 were treated with yellow jacket venom.

RESULTS

One hundred (99%) patients reached the maintenance dose. We observed 8 injection-related SRs (0.47% of all injections given) in 7 (6.9%) patients. The number of SRs was higher in patients treated with bee venom extract (12%) compared with in patients receiving yellow jacket venom extract (2%). There was no significant difference in the risk of SRs between female and male patients. The incidence of SRs was considerably lower than the average of 17.8% reported in the literature.

CONCLUSION

With a rush immunotherapy regimen over a time period of 8 years in predominantly high-risk patients, the incidence of SRs was low, despite the high number of patients with bee venom allergy, who are more likely to have side effects. Epinephrine as rescue medication was never necessary, and the regimen proved to be safe and convenient for both the patients and the medical staff.

Atrial fibrillation associated with anaphylaxis during venom and pollen immunotherapy

BACKGROUND

Electrographic changes after insect stings have been reported both with and without systemic symptoms. To our knowledge, however, there have been no reported cases of arrhythmias in the maintenance phase of venom or pollen immunotherapy.

OBJECTIVE

We report a case of a patient who developed paroxysmal atrial fibrillation after receiving venom and pollen immunotherapy. This patient was initially evaluated in an outpatient setting, and the events described occurred at an allergist's private office. We believe this is an atypical presentation and would be very pertinent to the practicing allergist.

METHODS

This patient was under the care of a clinical allergist in a private practice with associations to a teaching hospital. Interventions were as described in the body of the paper, more specifically venom and pollen maintenance immunotherapy followed by two doses of 0.3 mL of 1:1,000 concentration epinephrine intramuscularly.

RESULTS

Patient was found to be in atrial fibrillation along with systemic symptoms immediately after administration of immunotherapy. After epinephrine administration, patient converted back to normal sinus rhythm and systemic symptoms resolved.

CONCLUSIONS

Atrial fibrillation is an atypical presentation of a systemic reaction to immunotherapy.

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.

Wasp venom rush immunotherapy induces transient downregulation of B cell surface molecule expression

BACKGROUND

Little is known about the involvement of B cells in venom immunotherapy (VIT). To elucidate changes in the B cell phenotype during this process, we examined the expression of several surface molecules on peripheral B cells before and during VIT.

METHODS

15 venom-allergic patients with a history of systemic reactions after a wasp sting and venom-specific skin test reactivity as well as serum IgE were investigated before VIT (day 1), 1 day after reaching a maintenance dose of 100 microg (day 6) during inpatient rush VIT, and again on day 26 during continued outpatient maintenance therapy. Changes in the serum levels of total IgE, allergen-specific IgE (sIgE) and sIgG4 were measured by ELISA. Expression of several surface molecules on double-labelled B cells was studied by flow cytometry of peripheral blood mononuclear cells.

RESULTS

Levels of total IgE, sIgE and sIgG4 showed a significant increase after 26 days of VIT. On day 6, cell surface expression of HLA- II-DR, CD5, CD32 and CD54 was decreased in intensity and numbers of positive cells compared to day 1, while on day 26, expression of these molecules approached again baseline levels. Furthermore, a trend to decreased CD23 was noted on day 6. No changes were observed for CD40, CD86, CD95 and HLA-I-ABC.

CONCLUSION

These data show that during initiation of rush VIT, B cell expression of surface molecules involved in T-B cell cooperation and antigen presentation is downmodulated. B cells may thus be additional direct or indirect targets of high-dose antigen therapy and contribute to the persistence of TH1 responses during maintenance VIT treatment.

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.

Discontinuing venom immunotherapy

The decision to discontinue venom immunotherapy requires a great deal of clinical judgement because of the potential for a life-threatening reaction to a sting. The risk of recurrence is a combination of the frequency of reaction and the severity of reaction. Early studies reported a relapse rate of 8-14% in radioallergosorbent test-negative patients when therapy was stopped after 3 years. Unfortunately, the venom skin test or radioallergosorbent test becomes negative in only 25% of patients after 5 years of treatment. An alternative criterion for stopping treatment after 5 years regardless of the skin test has been equally successful, with most post-treatment reactions being much milder than pre-treatment reactions. There was no evidence of a rebound of venom sensitivity when therapy was stopped, even when patients were stung. The level of venom-specific IgE antibodies is better suppressed by 5 than by 3 years of treatment. The risk of relapse is higher in honeybee-allergic patients and in patients who had a systemic reaction (to a sting or an injection) during therapy. The frequency of reaction may be low, but patients who had very severe pre-treatment reactions have a greater chance of the reaction being severe again, and should remain on therapy for life. Long-term observations show that the incidence of systemic reaction to a sting remains 10% for each sting that occurs, even 10-15 years after stopping treatment. Because patients may not react to one sting and then subsequently react to another sting, the cumulative frequency of sting reactions is approximately 17% after 10 years off treatment. Moreover, negative venom skin tests are not a guarantee of safety because there is almost the same 10% frequency of reaction in patients who appear to lose sensitivity. It is not yet clear whether some low-risk patients (children, mild reactors) could discontinue treatment after just 3 years.

Venom immunotherapy induces monocyte activation

BACKGROUND

Venom immunotherapy (VIT) is an efficient treatment of hymenoptera venom allergy. The mechanism of VIT is based on the induction of tolerance of allergen-specific Th2 cells. The mechanisms of this T cell modulation are unknown, and could depend on cytokines produced by other cell types such as interleukin (IL)-12, tumour necrosis factor (TNF)-alpha and IL-10 by monocytes.

OBJECTIVE

To assess if VIT modifies the monocyte production of IL-12, TNF-alpha and IL-10 during the 45 first days of treatment.

METHODS

Fourteen patients and seven controls were included. Blood samples were taken once in controls and at day (D)1, D30 and D45 of VIT in patients. Monocytes were isolated, cultured with and without lipopolysaccharide (LPS), and the culture supernatant was harvested. IL-10, IL-12 and TNF-alpha were assayed in supernatants by ELISA.

RESULTS

Baseline cytokine levels were not statistically different between patients and controls. During treatment, an increase of spontaneous monocyte production of IL-12 and TNF-alpha was observed at D15 and D45. The production of IL-10 increased at D15 and D45 but not significantly. After LPS-stimulation, IL-12, TNF-alpha and IL-10 monocyte production was not modified by VIT.

CONCLUSION

VIT induces a monocyte activation characterized by a delayed overproduction of IL-12 and TNF-alpha. These cytokines could be relevant to the inhibition of Th2 cells during VIT. Therefore, VIT-induced tolerance could depend not only on the specific action of venom antigens on T cells, but also on a secondary non-specific action of monocytes.