Background In 2009, we reported a novel form of delayed anaphylaxis to red meat that is related to serum IgE antibodies to the oligosaccharide galactose-α-1,3-galactose (alpha-gal). Most of these ...patients had tolerated meat for many years previously. The implication is that some exposure in adult life had stimulated the production of these IgE antibodies. Objectives We sought to investigate possible causes of this IgE antibody response, focusing on evidence related to tick bites, which are common in the region where these reactions occur. Methods Serum assays were carried out with biotinylated proteins and extracts bound to a streptavidin ImmunoCAP. Results Prospective studies on IgE antibodies in 3 subjects after tick bites showed an increase in levels of IgE to alpha-gal of 20-fold or greater. Other evidence included (1) a strong correlation between histories of tick bites and levels of IgE to alpha-gal (χ2 = 26.8, P < .001), (2) evidence that these IgE antibodies are common in areas where the tick Amblyomma americanum is common, and (3) a significant correlation between IgE antibodies to alpha-gal and IgE antibodies to proteins derived from A americanum ( rs = 0.75, P < .001). Conclusion The results presented here provide evidence that tick bites are a cause, possibly the only cause, of IgE specific for alpha-gal in this area of the United States. Both the number of subjects becoming sensitized and the titer of IgE antibodies to alpha-gal are striking. Here we report the first example of a response to an ectoparasite giving rise to an important form of food allergy.
Platelet-activating factor (PAF) has a direct role as a mediator in the pathogenesis of various disorders with an inflammatory component, including those with allergic aetiology. The peripheral blood ...concentration of PAF is dynamically regulated by plasma PAF acetylhydrolase (PAF-AH). Previous research suggest that low activity of plasma PAF-AH could be a predictive marker for increased severity of some types of allergic hypersensitivity reactions-especially anaphylaxis. The purpose of the study was to evaluate the association between plasma PAF-AH activity and severity in patients with anaphylactic reactions following a wasp or bee sting.
The study group of 89 patients was divided into two subgroups depending on the increasing severity of the most severe anaphylactic reaction in the past, which was assessed according to the Müller's scale. The first subgroup included participants with a history of hypersensitivity reactions up to grade II. The second subgroup consisted of patients who have experienced at least one grade III or IV reactions in the past. A control group of 20 people was established. Plasma PAF-AH activity was measured using a colorimetric method.
It has been observed that plasma activity of platelet-activating factor acetylhydrolase was significantly lower in patients with anaphylaxis history compared to the control group with negative atopic history (on average 21.38 nmol/min/ml for the control group, 9.47 nmol/min/ml for the first subgroup and 10.16 nmol/min/ml for the second subgroup, in both cases p < 0.0001).
The plasma activity of PAF-AH is a promising parameter that can help to distinguish a group of patients not threatened with development of anaphylaxis and not requiring laborious or expensive prophylactic procedures.
Hymenoptera venom allergy is an epidemiologically underestimated condition and a major cause of morbidity worldwide. Preventing future allergic reactions in patients who experience a systemic ...reaction is based on the correct management of the emergency followed by an accurate diagnosis, prescription of adrenaline autoinjectors, and, where indicated, specific venom immunotherapy. Some epidemiological studies highlight our poor knowledge of this disease and the frequent inadequacy of its management. Moreover, they emphasize the importance of such a life-saving treatment as specific immunotherapy. The availability of high-quality hymenoptera venom extracts for diagnostic and therapeutic use has dramatically improved the prognosis and quality of life of allergic patients. Subcutaneous venom immunotherapy is currently the most effective form of allergen-based immunotherapy, with a carry-over effect lasting up to several years after its interruption. This report on the management of hymenoptera venom-allergic children and adults was prepared by a panel of Italian experts. The main objective of this consensus document is to review the scientific evidence related to diagnosis, therapy, and management of patients allergic to hymenoptera venom. Thus, we can improve our knowledge of the disease and promote good clinical practices. The present document provides practical suggestions for correct diagnosis, prescription of emergency therapy and immunotherapy, and strategies for patient care.
The antimalarial efficacy of the most important vector control interventions—long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS)—primarily protect against mosquitoes’ biting ...people when they are in bed and indoors. Mosquito bites taken outside of these times contribute to residual transmission which determines the maximum effectiveness of current malaria prevention. The likelihood mosquitoes feed outside the time of day when LLINs and IRS can protect people is poorly understood, and the proportion of bites received outdoors may be higher after prolonged vector control. A systematic review of mosquito and human behavior is used to quantify and estimate the public health impact of outdoor biting across Africa. On average 79% of bites by the major malaria vectors occur during the time when people are in bed. This estimate is substantially lower than previous predictions, with results suggesting a nearly 10% lower proportion of bites taken at the time when people are beneath LLINs since the year 2000. Across Africa, this higher outdoor transmission is predicted to result in an estimated 10.6 million additional malaria cases annually if universal LLIN and IRS coverage was achieved. Higher outdoor biting diminishes the cases of malaria averted by vector control. This reduction in LLIN effectiveness appears to be exacerbated in areas where mosquito populations are resistant to insecticides used in bed nets, but no association was found between physiological resistance and outdoor biting. Substantial spatial heterogeneity in mosquito biting behavior between communities could contribute to differences in effectiveness of malaria control across Africa.
Key Issues in Hymenoptera Venom Allergy: An Update Alfaya Arias, T; Soriano Gómis, V; Soto Mera, T ...
Journal of investigational allergology & clinical immunology,
01/2017, Letnik:
27, Številka:
1
Journal Article
Recenzirano
Odprti dostop
In this review, the Hymenoptera Allergy Committee of the SEAIC analyzes the most recent scientific literature addressing problems related to the diagnosis of hymenoptera allergy and to management of ...venom immunotherapy. Molecular diagnosis and molecular risk profiles are the key areas addressed. The appearance of new species of hymenoptera that are potentially allergenic in Spain and the associated diagnostic and therapeutic problems are also described. Finally, we analyze the issue of mast cell activation syndrome closely related to hymenoptera allergy, which has become a new diagnostic challenge for allergists given its high prevalence in patients with venom anaphylaxis.
Insect bite hypersensitivity (IBH) is an allergic dermatitis of the horse caused by bites of insects of the genus Culicoides and is currently the best characterized allergic disease of horses. This ...article reviews knowledge of the immunopathogenesis of IBH, with a particular focus on the causative allergens. Whereas so far hardly any research has been done on the role of antigen presenting cells in the pathogenesis of IBH, recent studies suggest that IBH is characterized by an imbalance between a T helper 2 (Th2) and regulatory T cell (Treg) immune response, as shown both locally in the skin and with stimulated peripheral blood mononuclear cells. Various studies have shown IBH to be associated with IgE-mediated reactions against salivary antigens from Culicoides spp. However, until recently, the causative allergens had not been characterized at the molecular level. A major advance has now been made, as 11 Culicoides salivary gland proteins have been identified as relevant allergens for IBH. Currently, there is no satisfactory treatment of IBH. Characterization of the main allergens for IBH and understanding what mechanisms induce a healthy or allergic immune response towards these allergens may help to develop new treatment strategies, such as immunotherapy.
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.
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.
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.
Randomised controlled trials of venom immunotherapy using standardised venom extract in insect sting allergy.
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.
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.
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.
Differences in treatment approach still exist for children after systemic sting reactions. In addition, there are still some doubts about when systemic reactors should be treated with venom ...immunotherapy (VIT).
To determine the rate of sting recurrence and natural history of Hymenoptera venom allergy (HVA) in children not treated with VIT.
A total of 219 children diagnosed as having HVA who were not treated with VIT were identified in 3 pediatric allergology centers. Survey by telephone or mail with the use of a standardized questionnaire was conducted. The number of field re-stings, subsequent symptoms, and provided treatment were analyzed.
A total of 130 of the 219 patients responded to the survey, for a response rate of 59.4%. During the median follow-up period of 72 months (interquartile range, 52-85 months), 44 children (77% boys) were stung 62 times. Normal reactions were most common, occurring in 27 patients (62%). Severe systemic reactions (SSRs) occurred in 8 (18%) of those who were re-stung. The subsequent reaction was significantly milder (P < 0.001), especially in the case of patients re-stung by the same insect (P < .001). None of the children with prediagnostic large local reactions and negative test results for venom specific IgE developed SSRs after re-sting by the culprit insect (P = .03). In children with SSRs, median time from diagnosis to re-sting was 2 times longer than that in those with large local reactions and normal reactions (P = .007).
Most children with HVA not treated with VIT reported milder reactions after a re-sting. Probability of SSR to re-sting increases along with the severity of initial reaction.
To describe clinical effects and outcomes of hymenopteran stings and to explore the non-laboratory factors associated with adverse clinical outcomes, a composite outcome including death, respiratory ...failure requiring intubation, acute kidney injury (AKI) requiring dialysis and hypotension requiring vasopressor use.
A retrospective cross-sectional study was performed at the Ramathibodi Poison Center, a poison centre of a tertiary care hospital in Thailand. All cases of hymenopteran sting consultations from January 2015 to June 2019 were consecutively enrolled, and charts were reviewed. Demographics, initial clinical characteristics and outcomes were collected. Factors associated with adverse clinical outcome were explored.
One hundred and fourteen hymenopteran stings cases (wasp 48%, bee 33%, hornet 14% and carpenter bee 8.8%) were included (median age, 36.5 years (interquartile range 9-55); male 63%). The prevalence of adverse clinical outcomes was 12.3% (95%CI 6.88-12.8). At initial presentation, 100% of cases had local skin reactions, 11.4% were clinical anaphylaxis, and 8% had red urine. Adverse clinical outcomes included death (n = 10), respiratory failure requiring intubation (n = 9), AKI requiring dialysis (n = 6) and hypotension requiring vasopressor use (n = 2). None of the patients with carpenter bee or hornet stings developed adverse clinical outcomes. In univariable analysis, urticaria, wheezing, red urine, wasp sting and sting number > 10 were significantly associated with adverse clinical outcomes. In multivariable analysis, red urine (adjusted OR 11.1 (95% CI 1.57-216)), wheezing (adjusted OR 16.7 (95% CI 1.43-402)) and a number of stings > 10 (adjusted OR 21.5 (95% CI2.13-2557)) were significant.
Adverse clinical outcomes in hymenopteran stings were not uncommon among cases inquiring to a national Thai poison centre. At initial presentation, red urine, wheezing and a number stings >10 were significantly associated with adverse clinical outcomes. Larger epidemiologic studies are required to confirm these associations.
Aedes aegypti mosquitoes are responsible for transmitting many medically important viruses such as those that cause Zika and dengue. The inoculation of viruses into mosquito bite sites is an ...important and common stage of all mosquito-borne virus infections. We show, using Semliki Forest virus and Bunyamwera virus, that these viruses use this inflammatory niche to aid their replication and dissemination in vivo. Mosquito bites were characterized by an edema that retained virus at the inoculation site and an inflammatory influx of neutrophils that coordinated a localized innate immune program that inadvertently facilitated virus infection by encouraging the entry and infection of virus-permissive myeloid cells. Neutrophil depletion and therapeutic blockade of inflammasome activity suppressed inflammation and abrogated the ability of the bite to promote infection. This study identifies facets of mosquito bite inflammation that are important determinants of the subsequent systemic course and clinical outcome of virus infection.
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•Mosquito bites enhance virus replication and dissemination and increase host mortality•Neutrophil-driven inflammation retains virus in skin to drive macrophage recruitment•Recruited and resident myeloid cells become infected and replicate virus•Blocking leukocyte recruitment to bite site inhibits viral infection
The inoculation of viruses into mosquito bite sites is an important and common stage of arbovirus infections. McKimmie and colleagues show that inflammation at bite sites aids viral replication and dissemination in vivo, resulting in more severe infection. These findings define additional targets for post-exposure prophylactic intervention.
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