Risk assessment in anaphylaxis: current and future approaches

Dietary management of peanut and tree nut allergy: what exactly should patients avoid?

Peanut and tree nut allergies are the commonest cause of life-threatening food-allergic reactions and significantly affect quality of life in children and their families. Dietary nut avoidance and provision of emergency medication is currently the mainstay of treatment. Nut avoidance has consequences on both quality of life and nutrition. We review the terminology that may cause confusion and lead to unnecessary dietary restrictions. In peanut or tree nut-allergic children, introduction of specific nuts to which the child is not allergic may improve quality of life and should be considered in patients with multiple foods allergies, vegan or ethnic-specific diets, in whom nuts are an important source of protein. Nut-allergic consumers do not just need to avoid foods containing nuts as an ingredient, but also contend with pre-packed foods which frequently have precautionary allergen labelling (PAL) referring to possible nut contamination. Although the published rate of peanut contamination in 'snack' foods with PAL (see Box ) ranges from 0.9-32.4%, peanut contamination in non-snack items with PAL is far less common. We propose that in some peanut-allergic patients (depending on history of reactivity to trace levels of peanut, reaction severity, other medical conditions, willingness to always carry adrenaline, etc.), consideration may be given to allow the consumption of non-snack foods containing PAL following discussion with the patient's (and their family's) specialist. More work is needed to provide consumers with clearer information on the risk of potential nut contamination in pre-packed food. We also draw attention to the change in legislation in December 2014 that require mandatory disclosure of allergens in non-pre-packed foods.

Sugammadex and rocuronium-induced anaphylaxis

Perioperative anaphylaxis is a life-threatening clinical condition that is typically the result of drugs or substances used for anesthesia or surgery. The most common cause of anaphylaxis during anesthesia is reportedly neuromuscular blocking agents. Of the many muscle relaxants that are clinically available, rocuronium is becoming popular in many countries. Recent studies have demonstrated that succinylcholine (but also rocuronium use) is associated with a relatively high rate of IgE-mediated anaphylaxis compared with other muscle relaxant agents. Sugammadex is widely used for reversal of the effects of steroidal neuromuscular blocking agents, such as rocuronium and vecuronium. Confirmed cases of allergic reactions to clinical doses of sugammadex have also been recently reported. Given these circumstances, the number of cases of hypersensitivity to either sugammadex or rocuronium is likely to increase. Thus, anesthesiologists should be familiar with the epidemiology, mechanisms, and clinical presentations of anaphylaxis induced by these drugs. In this review, we focus on the diagnosis and treatment of anaphylaxis to sugammadex and neuromuscular blocking agents. Moreover, we discuss recent studies in this field, including the diagnostic utility of flow cytometry and improvement of rocuronium-induced anaphylaxis with the use of sugammadex.

Managing nut-induced anaphylaxis: challenges and solutions

The prevalence of peanut and tree nut allergy in the USA has increased, especially in the pediatric population. Nut allergy remains the leading cause of fatal anaphylactic reactions. Management of anaphylaxis includes not only treatment of symptoms during a reaction, but strict dietary avoidance and education on potential situations, which may place the patient at high risk for accidental exposure. Cross-reactivity between various nuts along with various cross-contamination sources should be discussed with all nut-allergic individuals. Exciting research continues to emerge on other potential treatments for patients allergic to nuts, including allergen immunotherapy. Results of such interventions have been encouraging, though further studies are needed regarding safety and long-term outcomes before these can be applied to clinical practice.

Large particulate allergens can elicit mast cell-mediated anaphylaxis without exit from blood vessels as efficiently as do small soluble allergens

Anaphylaxis is a rapid-onset, life-threatening allergic reaction in that IgE, mast cells and histamine are commonly involved. It can be experimentally induced in IgE-sensitized animals by intravenous injection of corresponding allergens, and the sign of anaphylactic reaction can be detected within minutes after allergen challenge. However, it remains puzzling why the anaphylactic reaction can be initiated in vivo so quickly, considering that allergens are delivered into the blood circulation while mast cells reside within peripheral tissues but not in the blood circulation. To address this issue, we compared two different forms of the same allergen, small soluble and large particulate ones, in their ability to induce anaphylaxis in IgE-sensitized mice. In contrast to our expectation, particulate allergens could induce anaphylaxis as quickly and efficiently as did soluble allergens, even though they remained inside of blood vessels. In vivo imaging analysis suggested the direct interaction of intravascular particulate allergens and perivascular mast cells across the capillary wall. Taken together with previous report that perivascular mast cells can capture IgE in the blood circulation by extending cell processes across the vessel wall, our findings imply that blood-circulating allergens, regardless of their size, can stimulate mast cells without exit from blood vessels, by means of cross-linking IgE on mast cell processes inserted into the vessel lumen, and hence initiate anaphylactic reaction so quickly.

Influence of honeybee sting on peptidome profile in human serum

The aim of this study was to explore the serum peptide profiles from honeybee stung and non-stung individuals. Two groups of serum samples obtained from 27 beekeepers were included in our study. The first group of samples was collected within 3 h after a bee sting (stung beekeepers), and the samples were collected from the same person a second time after at least six weeks after the last bee sting (non-stung beekeepers). Peptide profile spectra were determined using MALDI-TOF mass spectrometry combined with Omix, ZipTips and magnetic beads based on weak-cation exchange (MB-WCX) enrichment strategies in the mass range of 1–10 kDa. The samples were classified, and discriminative models were established by using the quick classifier, genetic algorithm and supervised neural network algorithms. All of the statistical algorithms used in this study allow distinguishing analyzed groups with high statistical significance, which confirms the influence of honeybee sting on the serum peptidome profile. The results of this study may broaden the understanding of the human organism’s response to honeybee venom. Due to the fact that our pilot study was carried out on relatively small datasets, it is necessary to conduct further proteomic research of the response to honeybee sting on a larger group of samples.

Evaluation of the anaphylactoid potential of Andrographis paniculata extracts using the popliteal lymph node assay and P815 cell degranulation in vitro

Background

The anaphylactoid reactions induced by andrographis injection have repeatedly been reported. The aim of our study was to evaluate the immuno-sensitizing potential of extracts from Andrographis paniculata Nees and to screen for the constituent that is responsible for inducing the anaphylactoid reaction.

Methods

In the direct popliteal lymph node assay (D-PLNA), female BALB/c mice were randomly divided into several groups with ten mice per group according to the experiment design, the right hind footpads of mice received a single subcutaneous injection of Andrographis paniculata (50 μl), and the left hind footpads received the same volume of vehicle. Seven days later, the mice were sacrificed by cervical dislocation, and the popliteal lymph nodes from both the left and right sides were removed. The weight (WI) and cellularity indices (CI) of the popliteal lymph nodes (PLNs) were then calculated, and the pathological changes of the PLNs were measured. In addition, P815 mast cells were collected for the in vitro cell degranulation experiment. The level of histamine, the percentage of cell degranulation and the ratio of ammonia glycosidase released were measured to further evaluate the potential allergenicity.

Results

Alcohol extract (AEE), ethyl acetate extract (EAE) and n-butanol extract (NBE) significantly increased the weight (WI > 2) and cell number (CI > 5) of PLNs (P < 0.05, P < 0.01). Additionally, all the three monomers of andrographis, namely NAD, AND, and DDA, significantly increased the weight (WI > 2) and cell number (CI > 5) of the PLNs (P < 0.05, P < 0.01). In the cell model, all of the different extract fractions (AEE, EAE and NBE) and the three monomers of andrographis markedly elevated the level of histamine, the percentage of cell degranulation and the ratio of ammonia glycosidase released.

Conclusion

The diterpene lactone compounds of Andrographis paniculata Nees (total lactones of andrographolide) may have a potential sensitizing capacity in andrographis injection.

Perioperative anaphylactic reactions: Review and procedure protocol in paediatrics

Perioperative anaphylactic reactions are immediate, hypersensitive reactions that are potentially life-threatening resulting from a sudden release of mediators from mast cells and basophiles, due to either immune (IgE or non-IgE mediated) or non-immune mechanisms. The most frequent causing agents are neuromuscular blocking agents (NMBAs), latex and antibiotics, with latex being the first cause in paediatrics. With regard to perioperative anaphylactic reactions, the usual early signs and symptoms of an anaphylactic reaction could be overlooked or erroneously interpreted and non-severe anaphylaxis could go undetected, with a risk of more severe reactions in the future. Using the data registered on the anaesthesia sheet, it is essential to establish a chronological relationship between drugs and/or substances administered and the reaction observed. An elevated level of tryptase confirms an anaphylactic reaction, but this does not usually increase in the absence of compromised circulation. An allergy study should be carried out preferably between 4 and 6 weeks after the reaction, using a combination of specific IgE, skin and controlled exposure tests (if indicated). Test sensitivity is good for NMBAs, latex, antibiotics, chlorhexidine, gelatine and povidone, and poor for barbiturates, opiates (these can give false positives since they are histamine releasers) and benzodiazepines. Special preventive measures should be taken, especially in the case of latex. We present the maximum concentrations recommended for skin tests, the recommended dosage to treat anaphylactic reactions in paediatrics and a procedure algorithm for the allergological study of these reactions.

Occupational anaphylaxis--an EAACI task force consensus statement

Anaphylaxis is a systemic allergic reaction, potentially life-threatening that can be due to nonoccupational or, less commonly, to occupational triggers. Occupational anaphylaxis (OcAn) could be defined as anaphylaxis arising out of triggers and conditions attributable to a particular work environment. Hymenoptera stings and natural rubber latex are the commonest triggers of OcAn. Other triggers include food, medications, insect/mammal/snake bites, and chemicals. The underlying mechanisms of anaphylactic reactions due to occupational exposure are usually IgE-mediated and less frequently non-IgE-mediated allergy or nonallergic. Some aspects of work-related allergen exposure, such as route and frequency of exposure, type of allergens, and cofactors may explain the variability of symptoms in contrast to the nonoccupational setting. When assessing OcAn, both confirmation of the diagnosis of anaphylactic reaction and identification of the trigger are required. Prevention of further episodes is important and is based on removal from further exposure. Workers with a history of OcAn should immediately be provided with a written emergency management plan and an adrenaline auto-injector and educated to its use. Immunotherapy is recommended only for OcAn due to Hymenoptera stings.

Anaphylaxis attributed to exercise: considerations for sports medicine specialists

Anaphylaxis is an unanticipated, acute, and sometimes life-threatening systemic reaction with variable clinical presentations that is typically mediated by immunoglobulin E and causes degranulation of mast cells and basophils. The onset of symptoms can occur within minutes or hours after exposure to a known or suspected trigger, and reactions sometimes progress very rapidly, which can lead to death. One trigger of anaphylaxis in younger adults is moderately intense physical exercise, which has been termed exercise-induced anaphylaxis (EIA). Although rare, EIA should be recognized as a distinct and potentially life-threatening form of physical allergy, and is often undetected or inadequately treated. The ingestion of specific foods, including seafood, tree nuts, and wheat, or a nonspecific meal consisting of multiple food components shortly before or after physical exertion, is sometimes, but not always, the principal precipitant of EIA. This article briefly explores the current hypotheses on the role of immunoglobulin E, response mediators, and physiologic changes that bring on EIA, and discusses the current recommendations for diagnosis, including allergen challenge and laboratory testing, emergency care, and long-term prevention and patient follow-up. Accurate diagnosis of EIA is critical to providing lifesaving therapy and care plans to patients at risk. With respect to the medical management of EIA, mainstay therapy with epinephrine is described. For those with a known history of EIA, a comprehensive anaphylaxis action plan is central to successful patient management. Furthermore, patient education is necessary to heighten awareness of the signs and symptoms of EIA and appropriate strategies for allergen avoidance and self-management of anaphylactic episodes with self-injectable epinephrine.

The role of leukotrienes in allergic diseases

Leukotrienes (LTs), both LTB4 and the cysteinyl LTs (CysLTs) LTC4, LTD4 and LTE4, are implicated in a wide variety of inflammatory disorders. These lipid mediators are generated from arachidonic acid via multistep enzymatic reactions through which arachidonic acid is liberated from membrane phospholipids through the action of phospholipase A2. LTB4 and CysLTs exert their biological effects by binding to cognate receptors, which belong to the G protein-coupled receptor superfamily. LTB4 is widely considered to be a potent chemoattractant for most subsets of leukocytes, whereas CysLTs are potent bronchoconstrictors that have effects on airway remodeling. LTs play a central role in the pathogenesis of asthma and many other inflammatory diseases. This review will provide an update on the synthesis, biological function, and relevance of LTs to the pathobiology of allergic diseases, and examine the current and future therapeutic prospects of LT modifiers.

Optimal treatment of anaphylaxis: antihistamines versus epinephrine

Anaphylaxis is a rapid, systemic, often unanticipated, and potentially life-threatening immune reaction occurring after exposure to certain foreign substances. The main immunologic triggers include food, insect venom, and medications. Multiple immunologic pathways underlie anaphylaxis, but most involve immune activation and release of immunomodulators. Anaphylaxis can be difficult to recognize clinically, making differential diagnosis key. The incidence of anaphylaxis has at least doubled during the past few decades, and in the United States alone, an estimated 1500 fatalities are attributed to anaphylaxis annually. The increasing incidence and potentially life-threatening nature of anaphylaxis coupled with diagnostic challenges make appropriate and timely treatment critical. Epinephrine is universally recommended as the first-line therapy for anaphylaxis, and early treatment is critical to prevent a potentially fatal outcome. Despite the evidence and guideline recommendations supporting its use for anaphylaxis, epinephrine remains underused. Data indicate that antihistamines are more commonly used to treat patients with anaphylaxis. Although histamine is involved in anaphylaxis, treatment with antihistamines does not relieve or prevent all of the pathophysiological symptoms of anaphylaxis, including the more serious complications such as airway obstruction, hypotension, and shock. Additionally, antihistamines do not act as rapidly as epinephrine; maximal plasma concentrations are reached between 1 and 3 hours for antihistamines compared with < 10 minutes for intramuscular epinephrine injection. This demonstrates the need for improved approaches to educate physicians and patients regarding the appropriate treatment of anaphylaxis.

Fatal anaphylaxis in the United States, 1999-2010: temporal patterns and demographic associations

BACKGROUND

Anaphylaxis-related deaths in the United States have not been well characterized in recent years.

OBJECTIVES

We sought to define epidemiologic features and time trends of fatal anaphylaxis in the United States from 1999 to 2010.

METHODS

Anaphylaxis-related deaths were identified by using the 10th clinical modification of the International Classification of Diseases system diagnostic codes on death certificates from the US National Mortality Database. Rates were calculated by using census population estimates.

RESULTS

There were a total of 2458 anaphylaxis-related deaths in the United States from 1999 to 2010. Medications were the most common cause (58.8%), followed by "unspecified" (19.3%), venom (15.2%), and food (6.7%). There was a significant increase in fatal drug-induced anaphylaxis over 12 years: from 0.27 (95% CI, 0.23-0.30) per million in 1999 to 2001 to 0.51 (95% CI, 0.47-0.56) per million in 2008 to 2010 (P < .001). Fatal anaphylaxis caused by medications, food, and unspecified allergens was significantly associated with African American race and older age (P < .001). Fatal anaphylaxis to venom was significantly associated with white race, older age, and male sex (P < .001). The rates of fatal anaphylaxis to foods in male African American subjects increased from 0.06 (95% CI, 0.01-0.17) per million in 1999 to 2001 to 0.21 (95% CI, 0.11-0.37) per million in 2008 to 2010 (P < .001). The rates of unspecified fatal anaphylaxis decreased over time from 0.30 (95% CI, 0.26-0.34) per million in 1999 to 2001 to 0.09 (95% CI, 0.07-0.11) per million in 2008 to 2010 (P < .001).

CONCLUSION

There are strong and disparate associations between race and specific classes of anaphylaxis-related mortality in the United States. The increase in medication-related deaths caused by anaphylaxis likely relates to increased medication and radiocontrast use, enhanced diagnosis, and coding changes.

Anaphylaxis as a clinical manifestation of clonal mast cell disorders

Clonal mast cell disorders comprise a heterogeneous group of disorders characterized by the presence of gain of function KIT mutations and a constitutively altered activation-associated mast cell immunophenotype frequently associated with clinical manifestations related to the release of mast cells mediators. These disorders do not always fulfil the World Health Organization (WHO)-proposed criteria for mastocytosis, particularly when low-sensitive diagnostic approaches are performed. Anaphylaxis is a frequent presentation of clonal mast cell disorders, particularly in mastocytosis patients without typical skin lesions. The presence of cardiovascular symptoms, e.g., hypotension, occurring after a hymenoptera sting or spontaneously in the absence of cutaneous manifestations such as urticaria is characteristic and differs from the presentation of anaphylaxis in the general population without mastocytosis.

Anaphylaxis avoidance and management: educating patients and their caregivers

Anaphylaxis is an increasingly prevalent problem in westernized countries. Therefore, it is of utmost importance that the increasing numbers of patients at risk for anaphylaxis receive proper education on the etiology and risk factors as well as appropriate treatment of anaphylaxis with epinephrine. The physician’s role is crucial in order to educate the patients and care takers on effective measures to prevent anaphylaxis and empower them to take charge of early recognition and proper management of an anaphylactic reaction to prevent poor outcomes. This review summarizes the clinical presentation, triggers, avoidance, and management of anaphylaxis.

Risk factors for severe anaphylaxis in patients receiving anaphylaxis treatment in US emergency departments and hospitals

BACKGROUND

Although reported risk factors for severe anaphylaxis include older age, presence of comorbid medical conditions, and concomitant medications, previous studies have used varying definitions for anaphylaxis and heterogeneous methodology.

OBJECTIVE

To describe risk factors for severe anaphylaxis among US patients treated in emergency departments (EDs) or hospitals for anaphylaxis.

METHODS

Individuals with an ED visit/hospitalization for anaphylaxis were identified from 2 MarketScan Research Databases using an expanded International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code algorithm. Eligibility for the current study required continuous medical and prescription coverage for at least 1 year before and after the index date. Severe anaphylaxis was defined as a reaction requiring hospital admission.

RESULTS

Among 11,972 individuals, 2,622 (22%) had severe anaphylaxis. Unadjusted analysis showed that severe anaphylaxis was associated with older age and higher comorbidity burden. These patients were also less likely to have filled an epinephrine autoinjector (EAI) prescription or visited an allergist/immunologist, but more likely to have had an ED visit/hospitalization (any cause). On multivariable analysis, filling an EAI prescription (odds ratio [OR], 0.64; 95% CI, 0.53-0.78) or visiting an allergist/immunologist (OR, 0.78; 95% CI, 0.63-0.95) before the index event was associated with a lower risk of severe anaphylaxis, while any previous ED visit (OR, 1.18; 95% CI, 1.07-1.30) or hospitalization (OR, 1.55; 95% CI, 1.36-1.75) was associated with a higher risk of severe anaphylaxis.

CONCLUSIONS

In this large cohort with an ED visit or hospitalization for anaphylaxis, 22% had severe anaphylaxis. Pre-index preventive anaphylaxis care (ie, EAI prescription fill and allergist/immunologist visit) was associated with a significantly lower risk, supporting the benefits of preventive anaphylaxis care in real-world practice.

Systematic review of outcome measures in trials of pediatric anaphylaxis treatment

BACKGROUND

Considerable heterogeneity has been observed in the selection and reporting of disease-specific pediatric outcome measures in randomized controlled trials (RCTs). This makes interpretation of results and comparison across trials challenging. Outcome measures in pediatric anaphylaxis trials have never previously been systematically assessed. This systematic review (SR) identified and assessed outcome measures used in RCTs of anaphylaxis treatment in children. As a secondary objective, this SR assessed the evidence for current treatment modalities for anaphylaxis in the pediatric population.

METHODS

We searched MEDLINE, EMBASE, The Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL from 2001 until December 2012. We also searched websites listing ongoing trials. We included randomized and controlled trials of anaphylaxis treatment in patients 0-18 years of age. Two authors independently assessed articles for inclusion.

RESULTS

No published studies fulfilled the inclusion criteria.

CONCLUSIONS

There is an alarming absence of RCTs evaluating the treatments for anaphylaxis in children. High quality studies are needed and are possible to design, despite the severe and acute nature of this condition. Consensus about the selection and validation of appropriate outcome measures will enhance the quality of research and improve the care of children with anaphylaxis.

TRIAL REGISTRATION

CRD42012002685.

[Anaphylaxis. Diagnostic and therapeutic management]

Anaphylaxis is a severe, potentially life-threatening, systemic allergic reaction, which generally happens unexpectedly in healthy individuals. Among children, the most common elicitors are food, insect stings, and drugs. Currently, the incidence of anaphylaxis is increasing. Risk factors are asthma, infections as well as previous, sudden respiratory and cardiovascular symptoms after exposure to a specific antigen. If cutaneous, respiratory, gastrointestinal, cardiovascular and neurologic symptoms involving ≥2 organ systems occur, adrenaline/epinephrine, preferably intramuscularly, should be administered. Although allergen skin testing and serological estimation of specific IgE antibodies do not predict who will develop anaphylaxis, they help to identify sensitized individuals at risk. Patients with a history of anaphylaxis need training on how to use the emergency medication and how to recognize and prevent the anaphylactic symptoms.

The utility of serum tryptase in the diagnosis of food-induced anaphylaxis

Purpose

This study investigates the utility of serum tryptase for the confirmation of shrimp-induced anaphylaxis.

Methods

Patients with a history of shrimp allergy and positive skin prick tests (SPT) to commercial shrimp extract were recruited for shrimp challenges. Serum total tryptase was obtained at baseline and 60 min (peak) after the onset of symptoms.

Results

Thirty-nine patients were challenged. There were 12 patients with anaphylaxis, 20 with mild reactions and 7 without symptoms (control group). Characteristic features and baseline tryptase were not different among the 3 groups. The peak tryptase levels were higher than the baseline in anaphylaxis and mild reaction groups (P<0.05). The delta-tryptase (peak minus baseline) and the tryptase ratio (peak divided by baseline) in the anaphylaxis group were higher than the mild reaction and control groups (P<0.01). The optimum cut-off for peak tryptase to confirm anaphylaxis was 2.99 µg/L with 50% sensitivity, 85% specificity, 3.33 positive likelihood ratio (LR) and 0.59 negative LR. The manufacturer's cut-off for peak tryptase was >11.4 µg/L with 17% sensitivity, 100% specificity, infinity positive LR and 0.83 negative LR. The best cut-off for delta-tryptase was ≥0.8 µg/L with 83% sensitivity, 93% specificity, 11.86 positive LR and 0.18 negative LR. The best cut-off for tryptase ratio was ≥1.5 with 92% sensitivity, 96% specificity, 23 positive LR and 0.08 negative LR.

Conclusions

The peak tryptase level should be compared with the baseline value to confirm anaphylaxis. The tryptase ratio provide the best sensitivity, specificity, positive and negative LR than a single peak serum tryptase for the confirmation of shrimp-induced anaphylaxis.

Allergic reaction to peanuts: can we predict reaction severity in the wild?

Peanut allergy (PNA) is the main cause of food-induced anaphylaxis. Severe allergic reactions are more likely to occur in older patients and those with underlying asthma. Skin prick testing and measuring serum-specific IgE and recombinant peanut protein levels have been shown to be useful in the diagnosis of PNA and prediction of reactivity, but these tests are less consistent and reliable in terms of predicting the severity of reactions. Recent research has examined the role of biological mediators in allergic reactions such as platelet-activating factor. These may provide a future tool in predicting those at risk of severe reactions. Currently, there are no parameters that can predict with certainty those at risk of anaphylaxis, and management of PNA should continue to focus on patient and family education.

Basophil activation test in the diagnosis and monitoring of mastocytosis patients with wasp venom allergy on immunotherapy

BACKGROUND

There is need for an accurate diagnostic test in mastocytosis patients with wasp venom allergy (WVA) and monitoring of these patients during immunotherapy (IT). In this study, we aimed to evaluate sensitivity and specificity of the Basophil Activation Test (BAT) as a diagnostic and monitoring test in patients with mastocytosis and WVA.

METHODS

Seventeen patients with mastocytosis and WVA and six mastocytosis patients without WVA were included. BAT was performed before the start of IT (first visit) and at 6 weeks (second visit) and 1 year (third visit), after reaching the maintenance dose. Of 17 patients included, 11 completed the third visit. In mastocytosis patients with WVA, dose-dependent wasp-venom induced upregulation of CD63 and CD203c expression on basophils was observed compared with mastocytosis patients without WVA. Serum specific IgE, IgG4, and tryptase levels were measured in all patients.

RESULTS

BAT had a sensitivity of 87% and specificity of 100% in diagnosing WVA in mastocytosis patients. Basophil allergen threshold sensitivity with respect to CD63 and CD203c was significantly decreased in the second visit compared with the first visit and increased significantly in the third visit compared with the second visit. Specific IgE levels increased significantly in the second visit compared with first and decreased significantly in the third visit compared with the second. Specific IgG4 levels rose significantly in the second visit compared with the first and on the third visit compared with the second. Tryptase levels did not change significantly during the study.

CONCLUSIONS

BAT represents a diagnostic test with 100% specificity in allergic patients with mastocytosis and these patients are better to be monitored for a longer period during IT.

Antiallergic and Antiarthritic Effects of Stem Bark Extract of Glyphaea brevis (Spreng) Monachino (Tiliaceae) in Murine Models

Background. Various parts of Glyphaea brevis (Spreng) Monachino (Tiliaceae) find a use in traditional medicine in the treatment of pain and oedema among others. This study evaluates the anti-inflammatory, antiallergic, and antiarthritic effects of a 70% (v/v) aqueous ethanol extract of the stem bark of Glyphaea brevis in murine models. Materials and Methods. The effect of the aqueous ethanol extract of Glyphaea brevis extract (GBE) was assessed on the maximal and total oedema responses in the carrageenan-induced paw oedema in mice to evaluate the acute anti-inflammatory actions of the extract. Systemic anaphylaxis was induced with compound 48/80 and survival rates monitored for 1 h in mice with prior treatment with GBE to assess the anti-allergic action of the extract. The indirect antihistamine effect of GBE was evaluated on clonidine-induced catalepsy. Rat adjuvant-induced arthritis model was used to study GBE's antiarthritic action. Results. GBE significantly suppressed the mean maximal swelling and the total paw swellings over 6 h in the carrageenan-induced paw oedema when administered either prophylactically or therapeutically. GBE dose dependently increased the time for compound 48/80-induced mortality. Administered either prophylactically or therapeutically, GBE inhibited clonidine-induced catalepsy while it had no effect on haloperidol-induced catalepsy. GBE caused a significant dose-dependent suppression of Freund's adjuvant-induced arthritis. Conclusion. Glyphaea brevis inhibits the in vivo degranulation of mast cells and thereby suppress allergy. In addition it exhibits anti-inflammatory action and attenuates Freund's adjuvant-induced arthritis. The results of this work contribute to validate the traditional use of Glyphaea brevis in the management of inflammatory disorders.

Improvement of teacher food allergy knowledge in socioeconomically diverse schools after educational intervention

BACKGROUND

Increasingly, teachers are the first respondents to food allergic reactions in schools. Studies of food allergy in school settings have identified deficiencies in teacher recognition and treatment of reactions. We sought to determine the effect of a didactic session on teacher knowledge of the causative foods, symptoms, and treatment of reactions in diverse elementary schools.

METHODS

An educational intervention project using a pretest-posttest control group design was performed. Teacher knowledge about food allergy causes, symptoms, and treatment of food allergic reactions was assessed.

RESULTS

The average percentage of correctly answered questions by teachers at baseline for each school ranged from 60% to 68%. After education, teachers at the intervention schools answered 24.6% to 34.6% (confidence interval = 21.5-74.1 and 32.1-103.9, respectively) more questions correctly compared with 4.0% to 4.3% (confidence interval = 2.5-21.6 and 0.9-31.0, respectively) in control schools.

CONCLUSIONS

Education significantly increased teacher knowledge of food allergy causes, symptoms, and treatment of food allergic reactions in diverse schools.

Concomitant chronic pulmonary diseases and their association with hospital outcomes in patients with anaphylaxis and other allergic conditions: a cohort study

OBJECTIVES

To determine if chronic pulmonary diseases adversely impact selected outcomes in hospitalised patients who have various allergic conditions including anaphylaxis.

DESIGN

A population-based cohort study.

PARTICIPANTS

A statewide hospital inpatient discharge database from Texas, USA, covering the years 2004-2007 was analysed. Patients with anaphylaxis and other allergic conditions were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. Within each group of patients (the overall group with various selected allergic conditions and the subgroup with anaphylaxis), the exposure variables were 11 chronic pulmonary diseases including asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis.

PRIMARY OUTCOME MEASURES

Admission to an intensive care unit, a prolonged (>3 days) hospital stay, receipt of mechanical ventilation and death in hospital. Logistic regression was used to calculate adjusted OR and 95% CI for these four outcomes.

RESULTS

30 390 patients with allergic conditions were identified, of whom 2410 had anaphylaxis. The following results pertain to the subcohort of patients with anaphylaxis. Median age was 50 years (range 0-95 years) and 1470 (61%) were female. The hospital mortality was 2.7%. Although asthma was not associated with hospital mortality (OR=1.27, 95% CI 0.55 to 2.90), asthmatics had more than twice the odds of non-asthmatics of receiving mechanical ventilation (OR=2.45, 95% CI 1.81 to 3.33). Chronic bronchitis, COPD, emphysema and interstitial lung diseases (ILDs) were also associated with an increased risk of requiring mechanical ventilation. Chronic bronchitis and COPD were associated with a prolonged length of stay: OR=2.69 (95% CI 1.45 to 4.98) and OR=1.86 (95% CI 1.30 to 2.66), respectively. ILD was the only chronic pulmonary disease associated with an elevated risk of hospital mortality: OR=8.71 (95% CI 1.48 to 51.20).

CONCLUSIONS

In this unique analysis of a large database, we found that asthma, COPD and other chronic pulmonary diseases increased the risk of adverse outcomes among hospitalised patients with anaphylaxis.

Anaphylaxis in dogs and cats

OBJECTIVE

To review and summarize current information regarding the pathophysiology and clinical manifestations associated with anaphylaxis in dogs and cats. The etiology, diagnosis, treatment, and prognosis is discussed.

ETIOLOGY

Anaphylaxis is a systemic, type I hypersensitivity reaction that often has fatal consequences. Many of the principal clinical manifestations involve organs where mast cell concentrations are highest: the skin, the lungs, and the gastrointestinal tract. Histamine and other deleterious inflammatory mediators promote vascular permeability and smooth muscle contraction; they are readily released from sensitized mast cells and basophils challenged with antigen. Anaphylaxis may be triggered by a variety of antigens including insect and reptile venom, a variety of drugs, vaccines, and food.

DIAGNOSIS

Anaphylaxis is a clinical diagnosis made from a collection of signs and symptoms. It is most commonly based on pattern recognition. Differential diagnoses include severe asthma, pheocromocytoma, and mastocytosis.

THERAPY

Epinephrine is considered the drug of choice for the treatment of anaphylaxis. It acts primarily as a vasopressor in improving hemodynamic recovery. Adjunctive treatments include fluid therapy, H1 and H2 antihistamines, corticosteroids, and bronchodilators; however, these do not substitute for epinephrine.

PROGNOSIS

Prognosis depends on the severity of the clinical signs. The clinical signs will vary among species and route of exposure. The most severe clinical reactions are associated when the antigen is administered parenterally.

Common features of anaphylaxis in children

OBJECTIVE

We aimed to establish the characteristics of anaphylaxis in childhood.

METHODS

Forty-four patients who had experienced anaphylaxis in a period of 10 years (from 1999 to 2009), were included in the study. Parameters analysed were age, gender, concomitant allergic disease, trigger, setting, clinical symptoms, treatment, prognosis and prophylaxis.

RESULTS

The total numbers of anaphylaxis cases were 44 in a ten-year period. The ages of patients ranged from 3 to 14 years (11.50 ± 3.87 years) and the majority were male. 33 of the patients (75%) had a concomitant allergic disease. The trigger was determined in 93.2% of the cases, being most frequent: food (27.3%), and SIT (25%), followed by bee sting, medications and others. Respiratory (95.5%), dermatological (90.9%), cardiovascular (20.5%), neuropsychiatric (25%), and gastrointestinal (11.4%) symptoms were seen most frequently. For anaphylaxis triggered by food, the duration of anaphylactic episode was significantly longer (p<0.05). No biphasic reaction was observed during these attacks. Of our patients, only one developed respiratory failure and cardiac arrest due to SIT, and intensive care support was required.

DISCUSSION

As a trigger for anaphylaxis, the frequency of SIT is so high that it cannot be described by the study group including patients who were followed up in an outpatient allergy clinic.

Higher mast cell load decreases the risk of Hymenoptera venom-induced anaphylaxis in patients with mastocytosis

BACKGROUND

Increased basal serum tryptase (bsT) levels are a well-described risk factor for Hymenoptera venom-induced anaphylaxis (HVAn) in patients allergic to Hymenoptera venom. Increased bsT levels might also indicate the presence of mastocytosis. In this study we evaluated whether the risk of HVAn increases with increasing mast cell load in patients with mastocytosis.

METHODS

Consecutive patients with different subtypes of mastocytosis (n = 329) admitted to the University Medical Center Groningen were retrospectively assessed. As markers for mast cell load, levels of both bsT and the urinary histamine metabolites methylhistamine and methylimidazole acetic acid (MIMA) were used.

RESULTS

In the entire patient group, irrespective of disease subtype and Hymenoptera venom exposure, HVAn prevalence gradually increased with increasing marker levels to a maximum of 36% to 47% at a bsT level of 28.0 μg/L, a methylhistamine level of 231.0 μmol/mol creatinine, and a MIMA level of 2.7 mmol/mol creatinine but decreased thereafter with a further increase in these levels. In patients with indolent systemic mastocytosis with a history of Hymenoptera venom exposure after age 15 years or greater (n = 152), MIMA and age at the most recent Hymenoptera sting were independent predictors for HVAn (odds ratios of 0.723 [P = .001] and 1.062 [P < .001], respectively).

CONCLUSIONS

In patients with mastocytosis, HVAn prevalence does not increase constantly with increasing levels of mast cell load parameters: after a gradual increase to a maximum of near 50%, it decreases with a further increase in these levels. In the indolent systemic mastocytosis population, all mast cell load markers were independent negative predictors of HVAn. These findings suggest a complex pathophysiologic association between mast cell load and HVAn risk in patients with mastocytosis.

Anaphylaxis in the pediatric patient: optimizing management and prevention

Recent reports describing a rise in serious allergies and life-threatening reactions have prompted the need for pediatric nurse practitioners to re-evaluate and hone their clinical skills with regard to the recognition of anaphylaxis. An accredited symposium entitled, "Anaphylaxis in the Pediatric Patient: Optimizing Management and Prevention" was held in conjunction with the 2012 Annual Conference of the National Association of Pediatric Nurse Practitioners. This article is an accredited enduring activity from that symposium. Goals of this activity are to (a) provide participants with information regarding current trends in serious allergies and anaphylaxis, (b) discuss recommendations from clinical guidelines designed to standardize practice, and (c) address medical and educational needs of patients with anaphylaxis. This article focuses on the point of care where pediatric nurse practitioners require the diagnostic skills to determine whether a patient's acute symptoms are consistent with a diagnosis of anaphylaxis and whether epinephrine should be used to treat those symptoms. The rationale for the use of intramuscular epinephrine, insights into the development and execution of an emergency action plan, and patient education also are discussed.

Insect anaphylaxis: where are we? The stinging facts 2012

PURPOSE OF REVIEW

Insect allergy remains an important cause of morbidity and mortality in the United States. In 2011, the third iteration of the stinging insect hypersensitivity practice parameter was published, the first being published in 1999 and the second in 2004. Since the 2004 edition, our understanding of insect hypersensitivity has continued to expand and has been incorporated into the 2011 edition. This work will review the relevant changes in the management of insect hypersensitivity occurring since 2004 and present our current understanding of the insect hypersensitivity diagnosis and management.

RECENT FINDINGS

Since the 2004 commissioning by the Joint Task Force (JTF) on Practice Parameters of 'Stinging insect hypersensitivity: a practice parameter update', there have been important contributions to our understanding of insect allergy. These contributions were incorporated into the 2011 iteration. Similar efforts were made by the European Allergy Asthma and Clinical Immunology Interest Group in 2005 and most recently in 2011 by the British Society of Allergy and Clinical Immunology.

SUMMARY

Our understanding of insect allergy, including the natural history, epidemiology, diagnostic testing, and risk factors, has greatly expanded. This evolution of knowledge should provide improved long-term management of stinging insect hypersensitivity. This review will focus primarily on the changes between the 2004 and 2011 stinging insect practice parameter commissioned by the JTF on Practice Parameters, but will, where appropriate, highlight the differences between working groups.

A survey study of index food-related allergic reactions and anaphylaxis management

BACKGROUND

Initial food-allergic reactions are often poorly recognized and under-treated.

METHODS

Parents of food-allergic children were invited to complete an online questionnaire, designed with Kids with Food Allergies Foundation, about their children's first food-allergic reactions resulting in urgent medical evaluation.

RESULTS

Among 1361 reactions, 76% (95% CI 74-79%) were highly likely to represent anaphylaxis based on NIAID/FAAN criteria. Only 34% (95% CI 31-37%) of these were administered epinephrine. In 56% of these, epinephrine was administered by emergency departments; 20% by parents; 9% by paramedics; 8% by primary care physicians; and 6% by urgent care centers. In 26% of these, epinephrine was given within 15 min of the onset of symptoms; 54% within 30 min; 82% within 1 h; and 93% within 2 h. Factors associated with a decreased likelihood of receiving epinephrine for anaphylaxis included age <12 months, milk and egg triggers, and symptoms of abdominal pain and/or diarrhea. Epinephrine was more likely to be given to asthmatic children and children with peanut or tree nut ingestion prior to event. Post-treatment, 42% of reactions likely to represent anaphylaxis were referred to allergists, 34% prescribed and/or given epinephrine auto-injectors, 17% trained to use epinephrine auto-injectors, and 19% given emergency action plans. Of patients treated with epinephrine, only half (47%) were prescribed epinephrine auto-injectors.

CONCLUSIONS

Only one-third of initial food-allergic reactions with symptoms of anaphylaxis were recognized and treated with epinephrine. Fewer than half of patients were referred to allergists. There is still a need to increase education and awareness about food-induced anaphylaxis.

Recombinant IgE antibodies for passive immunotherapy of solid tumours: from concept towards clinical application

Therapeutic antibodies have revolutionised treatment of some cancers and improved prognosis for many patients. Over half of those available are approved for haematological malignancies, but efficacious antibodies for solid tumours are still urgently needed. Clinically available antibodies belong to the IgG class, the most prevalent antibody class in human blood, while other classes have not been extensively considered. We hypothesised that the unique properties of IgE, a class of tissue-resident antibodies commonly associated with allergies, which can trigger powerful immune responses through strong affinity for their particular receptors on effector cells, could be employed for passive immunotherapy of solid tumours such as ovarian and breast carcinomas. Our laboratory has examined this concept by evaluating two chimaeric antibodies of the same specificity (MOv18) but different isotype, an IgG1 and an IgE against the tumour antigen folate receptor α (FRα). The latter demonstrates the potency of IgE to mount superior immune responses against tumours in disease-relevant models. We identified Fcε receptor-expressing cells, monocytes/macrophages and eosinophils, activated by MOv18 IgE to kill tumour cells by mechanisms such as ADCC and ADCP. We also applied this notion to a marketed therapeutic, the humanised IgG1 antibody trastuzumab and engineered an IgE counterpart, which retained the functions of trastuzumab in restricting proliferation of HER2/neu-expressing tumour cells but also activated effector cells to kill tumour cells by different mechanisms. On-going efficacy, safety evaluations and future first-in-man clinical studies of IgE therapeutics constitute key metrics for this concept, providing new scope for antibody immunotherapies for solid tumours.

Food-induced anaphylaxis: mast cells as modulators of anaphylactic severity

A food-induced anaphylactic reaction can occur within seconds to a few hours following exposure to the causal food allergen and often affects multiple organ systems including gastrointestinal, cutaneous, respiratory, and cardiovascular. A conundrum in the allergy field is that consumption of the same allergen can cause reactions of vastly different severity in separate individuals; one patient may experience a mild non-life-threatening reaction characterized by pruritis of lips or urticaria whereas another may experience a life-threatening reaction that involves respiratory and cardiovascular compromise leading to loss of consciousness and sometimes death. While there are tests available to determine the predictive risk value of a positive food challenge test or clinical reactivity, there is currently no reliable method to distinguish between individuals who are at risk of mild non-life-threatening versus life-threatening reaction. Recent research has significantly advanced our understanding of the involvement of immune pathways in the effector phase of food-induced anaphylaxis; a void remains regarding our understanding of the contribution of these pathways to severity of disease. In this review, we discuss mild non-life-threatening versus life-threatening food-induced anaphylaxis and factors (co-morbidities and immune activation) that predispose individuals to more severe disease. Furthermore, we summarize recent advancements in our understanding of the involvement of underlying immune pathways in systemic and food-induced anaphylaxis in mouse systems and discuss how these pathways may contribute to more severe disease phenotype.

Mast cell anaphylatoxin receptor expression can enhance IgE-dependent skin inflammation in mice

BACKGROUND

Mast cells express receptors for complement anaphylatoxins C3a and C5a (ie, C3a receptor [C3aR] and C5a receptor [C5aR]), and C3a and C5a are generated during various IgE-dependent immediate hypersensitivity reactions in vivo. However, it is not clear to what extent mast cell expression of C3aR or C5aR influences C3a- or C5a-induced cutaneous responses or IgE-dependent mast cell activation and passive cutaneous anaphylaxis (PCA) in vivo.

OBJECTIVE

We sought to assess whether mouse skin mast cell expression of C3aR or C5aR influences (1) the cells' responsiveness to intradermal injections of C3a or C5a or (2) the extent of IgE-dependent mast cell degranulation and PCA in vivo.

METHODS

We measured the magnitude of cutaneous responses to intradermal injections of C3a or C5a and the extent of IgE-dependent mast cell degranulation and PCA responses in mice containing mast cells that did or did not express C3aR or C5aR.

RESULTS

The majority of the skin swelling induced by means of intradermal injection of C3a or C5a required that mast cells at the site expressed C3aR or C5aR, respectively, and the extent of IgE-dependent degranulation of skin mast cells and IgE-dependent PCA was significantly reduced when mast cells lacked either C3aR or C5aR. IgE-dependent PCA responses associated with local increases in C3a levels occurred in antibody-deficient mice but not in mice deficient in FcɛRIγ.

CONCLUSION

Expression of C3aR and C5aR by skin mast cells contributes importantly to the ability of C3a and C5a to induce skin swelling and can enhance mast cell degranulation and inflammation during IgE-dependent PCA in vivo.

Intestinal mast cell levels control severity of oral antigen-induced anaphylaxis in mice

Food-triggered anaphylaxis can encompass a variety of symptoms that affect multiple organ systems and can be life threatening. The molecular distinction between non-life-threatening and life-threatening modes of such anaphylaxis has not yet been delineated. In this study, we sought to identify the specific immune functions that regulate the severity of oral antigen-induced anaphylaxis. We thus developed an experimental mouse model in which repeated oral challenge of ovalbumin-primed mice induced an FcεRI- and IgE-dependent oral antigen-triggered anaphylaxis that involved multiple organ systems. Strikingly, the severity of the systemic symptoms of anaphylaxis (eg, hypothermia) positively correlated with the levels of intestinal mast cells (r = -0.53; P < 0.009). In addition, transgenic mice with both increased intestinal and normal systemic levels of mast cells showed increased severity of both intestinal and extra-intestinal symptoms of IgE-mediated passive as well as oral antigen- and IgE-triggered anaphylaxis. In conclusion, these observations indicate that the density of intestinal mast cells controls the severity of oral antigen-induced anaphylaxis. Thus, an awareness of intestinal mast cell levels in patients with food allergies may aid in determining their susceptibility to life-threatening anaphylaxis and may eventually aid in the treatment of food-triggered anaphylaxis.

Benefits and risks of IgA in immunoglobulin preparations

The case of Immunoglobulin A (IgA) in transfusion medicine is unsettled: on one hand IgA is an important component of adaptive immunity and its deficiency may cause disease, on the other its presence in blood products might induce, in rare instances, allergy-like symptoms if not anaphylaxis. The practice with i.v. immunoglobulins currently changes as up to 10% concentrated preparations are given at fast rates hence even trace amounts of IgA contained in these IgG preparations can cause unexpected (side-) effects. Fortunately, the spectrum of sensitive IgA assays, along with anti-IgA screening assays now permits laboratories to narrow down IgA-dependent transfusion reactions to the real cases, in which IgA was the decisive trigger of anaphylaxis, proven or not by the presence of anti-IgA of the IgG or even IgE class. Tolerance to allogenic IgA has recently been reported. The known association of HLA with IgA deficiency (IgAD) has now been completed with an association to the nonsynonymous variant in IFHI1, allowing physicians to more precisely spot recipients at risk for an IgA-dependent transfusion reaction. Our review, along with our own experience here in Switzerland, allows us to conclude that IgA is a beneficial antibody rather than an allergen to be placed at the end of the list of non-infectious transfusion complications such as TRALI, febrile non-hemolytic reactions, purpura or volume overload.

Insect anaphylaxis: addressing clinical challenges

PURPOSE OF REVIEW

Few allergic reactions are as potentially life-threatening, or frightening to the patient, as anaphylaxis. Food, medications, and insect stings are the three most common triggers of anaphylaxis, but insect allergy provides the best opportunity to understand the biology of anaphylaxis. If the physician can establish a diagnosis of insect allergy, treatment with nearly 98% effectiveness can be initiated. However, sometimes patients have a compelling history of insect sting anaphylaxis, but negative skin and blood tests. This situation presents us with a fascinating opportunity to understand the biology of insect anaphylaxis.

RECENT FINDINGS

Recent and ongoing work shows that occult mast cell disease may be critical in insect anaphylaxis. Mastocytosis, serum tryptase and basophil biology are key elements; genetic markers may potentially help us diagnose at-risk individuals and determine proper treatment. Understanding basophil activation may play an additional role both in diagnosis and knowing when therapy might be terminated.

SUMMARY

Mast cell disease, serum tryptase and basophil biology are providing an opportunity to better understand and manage insect allergy. This evolving understanding should improve long-term management of insect anaphylaxis and help us to better understand the clinical dilemma of appropriate management of the history-positive patient in which testing is unable to detect venom-specific IgE. Furthermore, omalizumab's immunomodulatory effects may play a role in difficult-to-treat insect allergy and mastocytosis. Finally, unrelated to these, but still important as an ongoing risk factor, is the continued underutilization of epinephrine for both acute and long-term management of insect anaphylaxis.

Sphingosine-kinase 1 and 2 contribute to oral sensitization and effector phase in a mouse model of food allergy

BACKGROUND

Sphingosine-1-phosphate (S1P) influences activation, migration and death of immune cells. Further, S1P was proposed to play a major role in the induction and promotion of allergic diseases. However, to date only limited information is available on the role of S1P in food allergy.

OBJECTIVE

We aimed to investigate the role of sphingosine-kinase (SphK) 1 and 2, the enzymes responsible for endogenous S1P production, on the induction of food allergy.

METHODS AND RESULTS

Human epithelial colorectal CaCo2 cells stimulated in vitro with S1P revealed a decrease of transepithelial resistance and enhanced transport of FITC labeled OVA. We studied the effect of genetic deletion of the enzymes involved in S1P production on food allergy induction using a mouse model of food allergy based on intragastrically (i.g.) administered ovalbumin (OVA) with concomitant acid-suppression. Wild-type (WT), SphK1(-/-) and SphK2(-/-) mice immunized with OVA alone i.g. or intraperitoneally (i.p.) were used as negative or positive controls, respectively. SphK1- and SphK2-deficient mice fed with OVA under acid-suppression showed reduced induction of OVA specific IgE and IgG compared to WT mice, but had normal responses when immunized by the intraperitoneal route. Flow cytometric analysis of spleen cells revealed a significantly reduced proportion of CD4(+) effector T-cells in both SphK deficient animals after oral sensitization. This was accompanied by a reduced accumulation of mast cells in the gastric mucosa in SphK-deficient animals compared to WT mice. Furthermore, mouse mast cell protease-1 (mMCP-1) levels, an IgE-mediated anaphylaxis marker, were reliably elevated in allergic WT animals.

CONCLUSION

Modulation of the S1P homeostasis by deletion of either SphK1 or SphK2 alters the sensitization and effector phase of food allergy.

Anaphylaxis: a history with emphasis on food allergy

In the century since Paul Portier and Charles Richet described their landmark findings of severe fatal reactions in dogs re-exposed to venom after vaccination with sea anemone venom, treatment for anaphylaxis continues to evolve. The incidence of anaphylaxis continues to be difficult to measure. Underreporting due to patients not seeking medical care as well as failure to identify anaphylaxis affects our understanding of the magnitude of the disease. Treatment with intramuscular epinephrine continues to be the recommended first-line therapy, although studies indicate that education of both the patients and the medical community is needed. Adverse food reactions continue to be the leading cause of anaphylaxis presenting for emergency care. Current therapy for food-induced anaphylaxis is built on the foundation of strict dietary avoidance, rapid access to injectable epinephrine, and education to recognize signs and symptoms of anaphylaxis. Investigation into therapy with oral and sublingual immunotherapy as well as other modalities holds hope for improved treatment of food-induced anaphylaxis.

Congruence of the current practices in Hymenoptera venom allergic patients in Poland with EAACI guidelines

INTRODUCTION

Venom immunotherapy (VIT) practice is the definitive treatment for patients with potentially fatal allergic reactions to Hymenoptera stings. The aim is assesing compliance of VIT practice in Poland with the current European Academy of Allergy and Clinical Immunology (EAACI) guidance.

MATERIAL AND METHODS

A multicentre study was carried out using a structured questionnaire which was sent by post to all VIT practitioners in Poland. Some questionnaire items were altered, in comparison to original version by adding additional answer options or alowing multiple answer option. The response rate was 100%. The obtained results were compared with the published EAACI guidelines.

RESULTS

Twenty-six Polish centres took part in the survey. SSIgE and skin prick tests (SPT) are together used as the first line of investigation, whereas confirmatory intradermal tests (IDT) are applied in half of centres. Only a few centres measure baseline serum tryptase levels. The ultra-rush protocol is preferred. Antihistamine pre-medication is routinely practiced. A target dose equal to 100 µg is used in most centres. A 6-week interval between booster doses is the most frequent. Five years is considered as an optimal VIT duration. Before the VIT completion, SSIgE is evaluated in fifty percent of centres, whereas sting challenge is considered by half of responders.

CONCLUSIONS

There are some differences between current practice in Poland and the EAACI recommendations, indicating areas requiring better compliance. Comparision between Poland and the United Kingdom revealed that health service organization and health care funding may play a major role in the provision of allergy services. This may affect the extent to which international guidance may be applied in individual countries. It is worth considering conducting the same survey in other European countries.

Venom immunotherapy in patients with mastocytosis and hymenoptera venom anaphylaxis

Systemic mastocytosis (SM) is typically suspected in patients with cutaneous mastocytosis (CM). In recent years, the presence of clonal mast cells (MCs) in a subset of patients with systemic symptoms associated with MC activation in the absence of CM has been reported and termed monoclonal MC activation syndromes or clonal systemic MC activation syndromes. In these cases, bone marrow (BM) MC numbers are usually lower than in SM with CM, there are no detectable BM MC aggregates, and serum baseline tryptase is often <20 µg/l; thus, diagnosis of SM in these patients should be based on careful evaluation of other minor WHO criteria for SM in reference centers, where highly sensitive techniques for immunophenotypic analysis and investigation of KIT mutations on fluorescence-activated cell sorter-purified BM MCs are routinely performed. The prevalence of hymenoptera venom anaphylaxis (HVA) among SM patients is higher than among the normal population and it has been reported to be approximately 5%. In SM patients with IgE-mediated HVA, venom immunotherapy is safe and effective and it should be prescribed lifelong. Severe adverse reactions to hymenoptera stings or venom immunotherapy have been associated with increased serum baseline tryptase; however, presence of clonal MC has not been ruled out in most reports and thus both SM and clonal MC activation syndrome might be underdiagnosed in such patients. In fact, clonal BM MC appears to be a relevant risk factor for both HVA and severe reactions to venom immunotherapy, while the increase in serum baseline tryptase by itself should be considered as a powerful surrogate marker for anaphylaxis. The Spanish Network on Mastocytosis has developed a scoring system based on patient gender, the clinical symptoms observed during anaphylaxis and serum baseline tryptase to predict for the presence of both MC clonality and SM among individuals who suffer from anaphylaxis.

An increase in serum tryptase even below 11.4 ng/mL may indicate a mast cell-mediated hypersensitivity reaction: a prospective study in Hymenoptera venom allergic patients

BACKGROUND

During a systemic hypersensitivity reaction (SR), an increase in serum tryptase compared to the baseline value is an indicator of mast cell activation, most often due to an IgE-mediated mechanism.

OBJECTIVE

To study the relevance of an increase in serum tryptase below the upper normal value of 11.4 ng/mL.

METHODS

Serum tryptase levels were measured in 35 patients with Hymenoptera venom hypersensitivity before and during venom exposure. Of these, 20 developed SR to stings or following venom injections during immunotherapy (reactors), while 15 tolerated reexposure to stings or venom injections during immunotherapy without SR (non-reactors). Serum tryptase was estimated at 2, 5 and 24 h after exposure and was compared to a baseline value obtained before or at least 72 h after exposure.

RESULTS

Considering circadian variation of serum tryptase, a relative increase to ≥135% of the baseline value (relative delta bound) was defined to indicate mast cell activation. Such an increase was observed in 17 of 20 reactors (85%), but none of 15 non-reactors. A serum tryptase of ≥11.4 ng/mL following venom exposure was observed in eight of the 20 reactors (40%) and 2 (13.3%) of the 15 non-reactors. Both these non-reactors also had an elevated baseline serum tryptase.

CONCLUSIONS AND CLINICAL RELEVANCE

Serum tryptase values obtained during a suspected hypersensitivity reaction must always be compared to a baseline value. A relative tryptase increase to ≥135% of the baseline value during a suspected hypersensitivity reaction indicates mast cell activation even below 11.4 ng/mL.