Anaphylaxis in the 21st century: phenotypes, endotypes, and biomarkers

COVID-19 vaccines: anaphylaxis and anxiety : A case study from an allergy unit

BACKGROUND

Vaccination against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) was one crucial element to overcome the coronavirus disease 2019 (COVID-19) pandemic. Even though anaphylaxis to vaccines is rare, 47 patients came to the Allergy Unit at the University Hospital Graz, Austria, reporting immediate anaphylactoid symptoms after administration of COVID-19 vaccines. In addition, 29 patients with known drug-induced anaphylaxis wanted to be tested for a possible sensitization against COVID-19 vaccines or excipients, such as polyethylene glycol (PEG) or polysorbate 80 (PS80) before the first COVID-19 vaccination. Skin prick tests and intradermal tests were performed in all 76 patients, mostly using PEG 2000, and/or PS80. Skin prick tests with COVID-19 vaccines were performed depending on availability.

OBJECTIVE

Our aim was to characterize this patient cohort in terms of patients' anaphylactoid responses, their willingness to future vaccinations against SARS-Cov‑2, and reasons for their decision.

METHODS

We developed a questionnaire and analyzed 34 completed copies.

RESULTS

Of the 47 patients with anaphylactoid reactions to COVID-19 vaccination, most were female (40 female/7 male). The skin tests, even when performed with the respective COVID-19 vaccine, were negative in all but one patient. Most patients who experienced anaphylactoid reactions after a COVID-19 vaccination, did not want another COVID-19 vaccination at the time of answering the questionnaire because of anxiety for another anaphylactoid response at the next shot. Premedication with antihistamines significantly lowered (n = 74 vaccinations) the severity of anaphylactoid responses after COVID-19 vaccinations.

CONCLUSION

Anxiety about another anaphylactoid episode hinders patients to be vaccinated against SARS-CoV‑2 again. Premedication with antihistamines and collaboration of allergologists with psychologists might lower the risk of an anaphylactic/anaphylactoid response as well anxiety in drug-induced anaphylactic patients.

Who is at-risk for severe anaphylaxis in France?

Background

The understanding of risk factors related to severe anaphylaxis is key to implementing prevention strategies. We present the first French population-based nine-year anaphylaxis hospitalization study evaluating specific trends and factors related to severe anaphylaxis (SA), to support identification of phenotypes at-risk.

Methods

This study used descriptive data from the French hospitalization database for the years 2012-2021, and included all patients hospitalized with anaphylaxis using International Classification of Diseases (ICD)-10 codes listed as a primary diagnosis. SA were cases that either required a hospitalization in intensive care units or resulted in death. Potential risk factors were identified according to corresponding ICD codes, available as secondary data during the patient's hospitalization.

Results

The average hospitalization rate of all cases of anaphylaxis (SA and non-SA) was 1.34/100,000/year, and rate of admissions for SA was 0.08/100,000/year. Among the 5463 SA, 37.7% had unspecified coding label, when trigger was not identified. For SA cases in which trigger was identified, most were related to drugs (45.6%), followed by food (9.3%) and insect sting (7.2%). Overall, admissions due to anaphylaxis (SA and non-SA) were more frequent in males (57%). However, when the trigger was drugs, the proportion was significantly higher in females. For children aged 5-9 years, the most common trigger for SA was food. Patients for which SA was triggered by insect stings were identified exclusively in the 10-14 years age group. Chronic spontaneous urticaria was associated with insect sting-induced anaphylaxis, regardless of the severity. Angioedema was associated with all causes of SA. Cases of anaphylaxis presenting with urticaria and angioedema included cases with identified and unidentified triggers. Asthma and a personal history of allergy were associated with drug- and food-induced anaphylaxis.

Conclusion

This is the first study to provide data on severe phenotypes of anaphylaxis in France. Data presented is key to the implementation of public health actions and preventive strategies to improve quality care.

Perioperative anaphylaxis: updates on pathophysiology

PURPOSE OF REVIEW

Perioperative anaphylaxis has historically been attributed to IgE/FcεRI-mediated reactions; there is now recognition of allergic and nonallergic triggers encompassing various reactions beyond IgE-mediated responses. This review aims to present recent advancements in knowledge regarding the mechanisms and pathophysiology of perioperative anaphylaxis.

RECENT FINDINGS

Emerging evidence highlights the role of the mast-cell related G-coupled protein receptor X2 pathway in direct mast cell degranulation, shedding light on previously unknown mechanisms. This pathway, alongside traditional IgE/FcεRI-mediated reactions, contributes to the complex nature of anaphylactic reactions. Investigations into the microbiota-anaphylaxis connection are ongoing, with potential implications for future treatment strategies. While serum tryptase levels serve as mast cell activation indicators, identifying triggers remains challenging. A range of mediators have been associated with anaphylaxis, including vasoactive peptides, proteases, lipid molecules, cytokines, chemokines, interleukins, complement components, and coagulation factors.

SUMMARY

Further understanding of clinical endotypes and the microenvironment where anaphylactic reactions unfold is essential for standardizing mediator testing and characterization in perioperative anaphylaxis. Ongoing research aims to elucidate the mechanisms, pathways, and mediators involved across multiple organ systems, including the cardiovascular, respiratory, and integumentary systems, which will be crucial for improving patient outcomes.

Hypersensitivity reactions to anticancer chemotherapy and monoclonal antibodies: Safety and efficacy of desensitization

BACKGROUND

Hypersensitivity reactions to anticancer chemotherapy and monoclonal antibodies may lead to discontinuation of first-line treatment options. Identification of these reactions can provide specific diagnosis and treatment by rapid drug desensitizations.

OBJECTIVE

To determine the hypersensitivity reactions involved in anticancer chemotherapy and monoclonal antibodies, and the safety and efficacy of rapid drug desensitization.

METHODS

We conducted an observational study of hypersensitivity reaction presented after the administration of anticancer chemotherapy and monoclonal antibodies in Mexico. We documented the symptoms of initial reaction and their severity, and the results of skin tests. We also report our experience of the administration of 12-step (mild-moderate reactions) and 16-step (severe reactions) desensitization protocols in these patients.

RESULTS

Overall, 93 patients received 336 rapid drug desensitization; 105 to taxanes, 115 to platinum drugs, 101 to monoclonal antibodies, and 15 other anticancer chemotherapy. Hypersensitivity reaction to taxanes occurred in the first or second administration, platinum drugs after the sixth cycle, and rituximab in the first cycle. The most common symptom in carboplatin was urticaria, paclitaxel back pain, oxaliplatin and docetaxel dyspnea, and in the monoclonal antibodies cardiovascular symptoms. Skin tests were positive in 75% of the carboplatin group, and only 16.7% in docetaxel. There was a rapid drug desensitization success rate of 99.4% and 85.7% did not present any related hypersensitivity reaction.

CONCLUSION

The diagnosis of hypersensitivity reaction to anticancer chemotherapy and monoclonal antibodies offers a panorama in the management of oncological diseases. Our standardized desensitization protocol is safe and effective and can be reproduced in other centers to treat patients who need to maintain first-line treatment.

Identifying patients at risk of anaphylaxis

Anaphylaxis is an acute, potentially fatal, systemic hypersensitivity reaction that warrants prompt diagnosis and management. It continues to be challenging to anticipate who may be at risk of a severe, life-threatening allergic reaction. Anaphylaxis can be caused by a range of allergens, such as certain foods, medications, latex, insect stings, etc. Cofactors that augment the severity of clinical symptoms and increase the risk of poor outcomes include exercise, stress, infectious diseases, underlying mast cell disease, active allergic disease such as asthma, advanced age, intake of certain medications, history of previous anaphylaxis, and delayed or missed administration of adrenaline. According to the European Anaphylaxis Registry, food is the major elicitor of anaphylaxis, especially eggs, cow milk, and nuts, in children and adolescents. Reaction to insect venom has also been noted in young adulthood. Early recognition of signs and symptoms and prompt treatment are crucial in anaphylaxis management to avoid serious and even fatal outcomes. It is crucial for both individuals and clinicians to identify the cause of anaphylaxis. Biomarkers of anaphylaxis, such as histamine, tryptase, platelet activation factor (PAF), chymase, carboxypeptidase A3, dipeptidyl peptidase I (DPPI), basogranulin, CCL-2, hsa-miR-451a, may be useful in diagnosis and management. The purpose of this review article is to present a comprehensive overview of current evidence and expert opinions regarding the risk factors that predispose individuals to anaphylaxis. Additionally, it provides insights into potential biomarkers and genetic markers for accurate diagnosis and management. This review underscores the significance of expert guidance in enhancing patient outcomes and enabling self-management of anaphylactic episodes.

Differential presentation of hypersensitivity reactions to carboplatin and oxaliplatin: Phenotypes, endotypes, and management with desensitization

BACKGROUND

Drug hypersensitivity reactions (DHRs) to platinum-based drugs are heterogenous and restrict their access, and drug desensitization (DD) has provided a ground-breaking procedure for their re-introduction, although the response is heterogeneous. We aimed to identify the phenotypes, endotypes, and biomarkers of reactions to carboplatin and oxaliplatin and their response to DD.

METHODS

Seventy-nine patients presenting with DHRs to oxaliplatin (N = 46) and carboplatin (N = 33) were evaluated at the Allergy Departments of two tertiary care hospitals in Spain. Patient symptoms, skin testing, biomarkers, and outcomes of 267 DDs were retrospectively analyzed.

RESULTS

Oxaliplatin-reactive patients presented with type I (74%), cytokine release reaction (CRR) (11%), and mixed (Mx) (15%) phenotypes. In contrast, carboplatin reactive patients presented with predominantly type I (85%) and Mx (15%) but no CRRs. Out of 267 DDs, breakthrough reactions (BTRs) to oxaliplatin occurred twice as frequently as carboplatin (32% vs. 15%; p < .05). Phenotype switching from type I to another phenotype was observed in 46% of oxaliplatin DDs compared to 21% of carboplatin DDs. Tryptase was elevated in type I and Mx reactions, and IL-6 in CRR and Mx, indicating different mechanisms and endotypes.

CONCLUSION

Carboplatin and oxaliplatin induced three different types of reactions with defined phenotypes and endotypes amendable to DD. Although most of the initial reactions for both were type I, oxaliplatin presented with unique CRR reactions. During DD, carboplatin reactive patients presented mostly type I BTR, while oxaliplatin-reactive patients frequently switched from type I to CRR, providing a critical difference and the need for personalized DD protocols.

A case-control study for comorbidity and laboratory factors associated with food-induced anaphylaxis

Background: Food-induced anaphylaxis (FIA) is a serious and potentially life-threatening allergic reaction triggered by food allergens. Objective: This case-control study aimed to investigate comorbidities and laboratory factors associated with FIA in the pediatric population of Israel. Methods: Retrospective data from the electronic health records of Leumit Health Care Services were used to identify 711 pediatric patients with FIA and 2560 subjects with food allergy and without anaphylaxis matched for age, gender, and ethnicity. Comorbidities were identified based on medical billing diagnosis codes, and laboratory characteristics were compared between the two groups. Results: The mean ± standard deviation age of patients with FIA was 4.1 ± 4.1 years, and 37.3% were girls. Laboratory analysis revealed increased eosinophil counts (p < 0.001), elevated immunoglobulin E (IgE) (p < 0.001), and IgA levels (p = 0.001) in the FIA group compared with the controls. With regard to comorbidities, the FIA group had higher prevalence rates of allergic diseases, including allergic rhinitis (odds ratio [OR] 1.72; p < 0.001), allergic conjunctivitis (OR 1.84; p = 0.001), asthma (OR 1.36; p < 0.001), angioedema (OR 6.37; p < 0.001), atopic dermatitis (OR 1.77; p < 0.001), and contact dermatitis (OR 1.42; p = 0.001). There was a trend toward significance for chronic spontaneous urticaria (p = 0.051). There was a significant negative association between helminthiases, particularly enterobiasis, and FIA (OR 0.76 [95% confidence interval, 0.59-0.98]; p = 0.029). Conclusion: This study provides valuable epidemiologic evidence on the associations among FIA, comorbidities, and laboratory factors in the pediatric population.

Evaluation of hemostatic derangements associated with canine anaphylaxis and the relationship to syndrome severity

OBJECTIVE

To describe hemostatic derangements associated with canine anaphylaxis and to assess for association with syndrome severity.

DESIGN

Prospective observational study.

SETTING

University teaching hospital.

ANIMALS

Twenty-seven client-owned dogs, recruited from November 2018 to January 2022, diagnosed with anaphylaxis of varying severity were included. Study inclusion required presentation <6 hours after initiation of clinical signs, no medications or history of illness within the prior 2 weeks, lack of comorbidities expected to affect hemostasis, and lack of a disease state that could alternatively explain the clinical presentation.

INTERVENTIONS

Blood samples were collected within the first hour of presentation for CBC, serum biochemistry, prothrombin time (PT), activated partial thromboplastin time (aPTT), and viscoelastic coagulation testing for use with a cartridge-based point-of-care device.

MEASUREMENTS AND MAIN RESULTS

Clotting time and clot formation time were prolonged, alpha angle and maximum clot firmness were decreased, PT and aPTT were prolonged, and platelet counts were lower in severe cases compared to mild and moderate cases. There were no differences for any parameter between mild and moderate cases. The presence or absence of abdominal effusion was not associated with hemostatic status.

CONCLUSIONS

Global hemostatic derangements consistent with hypocoagulability are a prominent feature of severe anaphylaxis in dogs and should be considered for routine evaluation.

Interleukin-6 as a biomarker of hypersensitivity reactions in chemotherapeutics and monoclonal antibodies

BACKGROUND

In recent years, a new type of immediate hypersensitivity reaction known as cytokine release began to emerge, and within this phenotype of reactions, interleukin-6 is the most frequently associated with the presence during drug administration. Chemotherapeutic agents (QT) and monoclonal antibodies.

OBJECTIVE

Determine interleukin-6 levels in hypersensitivity reactions to QT and monoclonal antibodies.

METHODS

Observational and prospective study that was carried out from March 1, 2021 to March 1, 2022 in a university hospital in northeastern Mexico. Symptoms, severity, interleukin-6 levels, and skin tests of hypersensitivity reaction were evaluated at QT and monoclonal antibodies.

RESULTS

A total of 41 patients with oncological disease were included, the most frequent being ovarian cancer. Symptoms as initial hypersensitivity reaction were neuromuscular in taxanes and cutaneous in Platinums.41.5% presented elevation of interleukin-6, and it was found more frequently in presence of metastases. Positive skin tests were found more frequently in the carboplatin and doxorubicin groups. The most frequently presented phenotype was type I in paclitaxel, carboplatin, and doxorubicin, and mixed-reaction (type I and cytokine release) in oxaliplatin.

CONCLUSION

With the increasing prevalence of hypersensitivity reactions to biologic and antineoplastic therapies, interleukin-6 should be recognized as a biomarker in immediate hypersensitivity reactions to QT and monoclonal antibodies.

Anaphylaxis due to antiallergic and antiasthmatic biologics

PURPOSE OF REVIEW

To provide a better understanding of the risk of anaphylaxis due to antiallergic and antiasthmatic biologics through an analysis of data reported in literature and in clinical trials, and by conducting a retrospective descriptive analysis of individual case safety reports on VigiBase, the WHO International Pharmacovigilance database.

RECENT FINDINGS

Analysis of the data, as described, demonstrated safety of the antiallergic and antiasthmatic biologics with a low incidence of anaphylaxis.

SUMMARY

Biologic therapies have revolutionized the treatment of many diseases, such as atopic dermatitis, nasal polyps, spontaneous chronic urticarial and severe asthma with a precise immunological action, in the sphere of precision medicine.Albeit these drugs are generally well tolerated, generating real-world evidence is crucial to re-evaluate clinically relevant adverse events, such as anaphylaxis, allowing to confirm their safety profile in particular in special populations such as paediatric patients.

Hypersensitivity Reactions to Taxanes: A Comprehensive and Systematic Review of the Efficacy and Safety of Desensitization

Taxanes in the treatment of cancer are associated with a significant incidence of hypersensitivity reactions, which may preclude their use in patients in need of first line therapy. Drug desensitization induces transient immunological tolerance and has allowed the reintroduction of taxanes in highly allergic patients. Increase the knowledge of hypersensitivity reactions (HSR) during the administration of taxanes. A systematic review regarding the safety and efficacy of rapid drug desensitization (RDD) for taxanes HSR. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, was registered in PROSPERO(CRD42021242324) and a comprehensive search was conducted in Medline, Embase, Web of Science and Scopus databases. 25 studies encompassing 10 countries were identified and 976 patients with initial HSR to paclitaxel (n = 707) and docetaxel (n = 284), that underwent a total of 2,396 desensitizations. The most common symptoms were cutaneous (74.6%) with paclitaxel and respiratory (72.6%) with docetaxel. Severe initial hypersensitivity reactions including anaphylaxis occurred in 39.6% and 13% of paclitaxel and docetaxel cases respectively and during the first (87.4%) or second exposure (81.5%). Patients tolerated well RDD and breakthrough reactions (BTR) occurred in 32.2% of paclitaxel-treated patients and in 20.6% of docetaxel treated patients. Premedications included corticosteroids, antihistamines and leukotriene receptor antagonists. The most commonly used protocol was the BWH 3 bags 12 steps, all protocols showed a success rate between 95-100%, with no reported deaths. RDD is a safe and effective procedure in patients with HSR to taxanes and protocols should be standardized for wide range implementation.

Food-Induced Anaphylaxis: Data From the European Anaphylaxis Registry

BACKGROUND

Food is one of the most common elicitors of anaphylaxis, with an increasing incidence over recent years.

OBJECTIVES

To characterize elicitor-specific phenotypes and identify factors enhancing the risk or severity of food-induced anaphylaxis (FIA).

METHODS

We analyzed data from the European Anaphylaxis Registry applying an age- and sex-matched analysis of associations (Cramer's V) for single food triggers and calculated odds ratios (ORs) for severe FIA.

RESULTS

We identified 3,427 cases of confirmed FIA showing an age-dependent elicitor ranking (for children: peanut, cow's milk, cashew, and hen's egg; and for adults: wheat flour, shellfish, hazelnut, and soy). The age- and sex-matched analysis revealed defined symptom patterns for wheat and cashew. Wheat-induced anaphylaxis was more frequently associated with cardiovascular symptoms (75.7%; Cramer's V = 0.28) and cashew-induced anaphylaxis with gastrointestinal symptoms (73.9%; Cramer's V = 0.20). Furthermore, concomitant atopic dermatitis was slightly associated with anaphylaxis to hen's egg (Cramer's V = 0.19) and exercise was strongly associated with anaphylaxis to wheat (Cramer's V = 0.56). Additional factors influencing the severity were alcohol intake in wheat anaphylaxis (OR = 3.23; CI, 1.31-8.83) and exercise in peanut anaphylaxis (OR = 1.78; CI, 1.09-2.95).

CONCLUSIONS

Our data show that FIA is age-dependent. In adults, the range of elicitors inducing FIA is broader. For some elicitors, the severity of FIA seems to be related to the elicitor. These data require confirmation in future studies considering a clear differentiation between augmentation and risk factors in FIA.

Inhaled mRNA therapy for treatment of cystic fibrosis: Interim results of a randomized, double-blind, placebo-controlled phase 1/2 clinical study

BACKGROUND

MRT5005, a codon-optimized CFTR mRNA, delivered by aerosol in lipid nanoparticles, was designed as a genotype-agnostic treatment for CF lung disease.

METHODS

This was a randomized, double-blind, placebo-controlled Phase 1/2 study performed in the US. Adults with 2 severe class I and/or II CFTR mutations and baseline ppFEV1 values between 50 and 90% were randomized 3:1 (MRT5005: placebo). Six dose levels of MRT5005 (4, 8, 12, 16, 20, and 24 mg) or placebo (0.9% Sodium Chloride) were administered by nebulization. The single ascending dose cohort was treated over a range from 8 to 24 mg; the multiple ascending dose cohort received five weekly doses (range 8-20 mg); and the daily dosing cohort received five daily doses (4 mg).

RESULTS

A total of 42 subjects were assigned to MRT5005 [31] or placebo [11]. A total of 14 febrile reactions were observed in 10 MRT5005-treated participants, which were mild [3] or moderate [11] in severity; two subjects discontinued related to these events. Additionally, two MRT5005-treated patients experienced hypersensitivity reactions, which were managed conservatively. The most common treatment emergent adverse events were cough and headache. No consistent effects on FEV1 were noted.

CONCLUSIONS

MRT5005 was generally safe and well tolerated through 28 days of follow-up after the last dose, though febrile and hypersensitivity reactions were noted. The majority of these reactions resolved within 1-2 days with supportive care allowing continued treatment with MRT5005 and careful monitoring. In this small first-in-human study, FEV1 remained stable after treatment, but no beneficial effects on FEV1 were observed.

Desensitization in children allergic to drugs: Indications, protocols, and limits

Any drug can potentially induce a hypersensitivity reaction. If after the allergological work-up the drug hypersensitivity reaction is confirmed, in most cases, the simple avoidance of the culprit drug and a suggestion of an unrelated alternative is enough. However, there are circumstances where the choice to stop the treatment affects the survival, the safety and/or the quality of life of the patient and the global outcome of the disease in question. When this occurs, drug desensitization can be the answer and should not be viewed as an extravagance, nor the pediatric age should be considered a contraindication. Drug desensitization in children can be safely and successfully performed, having a positive impact on the survival and overall prognosis. In general, the indications for DDS are the same in adults as in children. However, in this age group there are specificities that this paper aimed to describe, reviewing the mechanisms behind drug hypersensitivity and rapid drug desensitization, types of protocols, indications, and contraindications, as well as several technical aspects that are specific to the pediatric age.

Immediate hypersensitivity reactions to antineoplastic agents - A practical guide for the oncologist

Immediate hypersensitivity reactions (IHRs) to antineoplastic agents occur frequently, and every oncologist will encounter these reactions in their clinical practice at some point. The clinical signature of IHRs can range from mild to life-threatening, and their occurrence can substantially impede the treatment course of patients with cancer. Yet, clear guidelines regarding the diagnosis and management are scarce, especially from an oncologic point of view. Therefore, herein, we review the definition, pathophysiology, epidemiology, diagnosis and management of IHRs to chemotherapeutic agents and monoclonal antibodies. First, we focus on defining the specific entities that comprise IHRs and discuss their underlying mechanisms. Then, we summarize the epidemiology for the antineoplastic agents that represent the most common causes of IHRs, i.e., platinum compounds, taxanes and monoclonal antibodies (mAbs). Next, we describe the possible clinical pictures and the comprehensive diagnostic work-up that should be executed to identify the culprit and safe alternatives for the future. Finally, we finish with reviewing the treatment options in both the acute phase and after recovery, with the aim to improve the oncologic care of patients with cancer.

Clinical outcomes and management of contrast hypersensitivity in patients requiring repeated computed tomography imaging

Introduction

In collaboration with the Department of Rheumatology, Allergy and Immunology, our study aims to review the outcomes of and propose an improved workflow for the management of patients with prior hypersensitivity reactions to iodinated contrast media (ICM).

Method

Outpatients coming for contrast-enhanced computed tomography (CECT) were stratified into 3 categories (definite, unconfirmed and inaccurate) based on likelihood of their contrast hypersensitivity label. Patients could be offered a different ICM, receive the same ICM, or be referred to an allergist for further evaluation. There were 4 outcomes: (1) alternative ICM tolerated; (2) same ICM tolerated again; (3) patient developed a hypersensitivity reaction to either alternative or original ICM; and (4) CECT was deferred until assessment by an allergist. Comparison was made pre- and post-intervention to see if patient outcomes were improved.

Results

There were 132 patients who made a total of 154 visits (90.3% had documented contrast hypersensitivity). Post-intervention, the number of visits postponed for premedication decreased (81.0% to 34.7%). There was a reduction in hypersensitivity reactions (from 42.9% to 14.3%). Of the 12 patients assessed by the allergist, 6 could continue using the same or alternative ICM, 4 were advised to abstain from further contrast administration and 2 were pending testing with a third agent.

Conclusion

Active intervention by the radiologist can decrease the number of postponed, converted or cancelled CECT studies as well as reduce the number of adverse allergic-like events. Direct collaboration between radiologist and allergist for specific cases may be helpful in patients who will likely need future/repeated CECTs.

COVID-19 vaccines adverse events: potential molecular mechanisms

COVID-19 is an infectious disease caused by a single-stranded RNA (ssRNA) virus, known as SARS-CoV-2. The disease, since its first outbreak in Wuhan, China, in December 2019, has led to a global pandemic. The pharmaceutical industry has developed several vaccines, of different vector technologies, against the virus. Of note, among these vaccines, seven have been fully approved by WHO. However, despite the benefits of COVID-19 vaccination, some rare adverse effects have been reported and have been associated with the use of the vaccines developed against SARS-CoV-2, especially those based on mRNA and non-replicating viral vector technology. Rare adverse events reported include allergic and anaphylactic reactions, thrombosis and thrombocytopenia, myocarditis, Bell's palsy, transient myelitis, Guillen-Barre syndrome, recurrences of herpes-zoster, autoimmunity flares, epilepsy, and tachycardia. In this review, we discuss the potential molecular mechanisms leading to these rare adverse events of interest and we also attempt an association with the various vaccine components and platforms. A better understanding of the underlying mechanisms, according to which the vaccines cause side effects, in conjunction with the identification of the vaccine components and/or platforms that are responsible for these reactions, in terms of pharmacovigilance, could probably enable the improvement of future vaccines against COVID-19 and/or even other pathological conditions.

Novel small molecule MRGPRX2 antagonists inhibit a murine model of allergic reaction

BACKGROUND

Activation of Mas-related G protein-coupled receptor X2 (MRGPRX2) is a crucial non-IgE pathway for mast cell activation associated with allergic reactions and inflammation. Only a few peptides and small compounds targeting MRGPRX2 have been reported, with limited information on their pharmacologic activity.

OBJECTIVE

We sought to develop novel small molecule MRGPRX2 antagonists to treat MRGPRX2-mediated allergies and inflammation.

METHODS

A computational approach was used to design novel small molecules as MRGPRX2 antagonists. The short-listed molecules were synthesized and characterized by liquid chromatography and mass spectrometry as well as nuclear magnetic resonance. Inhibitory activity on MRGPRX2 signaling was assessed in vitro by using functional bioassays (β-hexosaminidase, calcium flux, and chemokine synthesis) and receptor activation assays (β-arrestin recruitment and Western blot analysis) in human LAD-2 mast cells and HTLA cells. In vivo effects of the novel MRGPRX2 antagonists were assessed using a mouse model of acute allergy and systemic anaphylaxis.

RESULTS

The novel small molecules demonstrated higher binding affinity with MRGPRX2 in the docking study. The half-maximal inhibitory concentration is in the low micromolar range (5-21 μM). The small molecules inhibited not only the early phase of mast cell activation but also the late phase, associated with chemokine and prostaglandin release. Further, Western blot analysis revealed inhibition of downstream phospholipase C-γ, extracellular signal-regulated protein kinase 1/2, and Akt signaling pathway. Moreover, in the mouse models of allergies, small molecule administration effectively blocks acute, systemic allergic reactions and inflammation and prevents systemic anaphylaxis.

CONCLUSION

The small molecules might hold a significant therapeutic promise to treat MRGPRX2-mediated allergies and inflammation.

Hypersensitivity reactions to folinic acid: mechanisms involved based on two case reports and a literature review

BACKGROUND

Hypersensitivity reactions (HSR) to antineoplastic agents are an increasing problem, especially when they lead to treatment discontinuation, sometimes without any equivalent therapeutic option. HSR to folinic acid (FA), used particularly for the treatment of digestive carcinoma along with oxaliplatin and 5-fluorouracil, are rare. Only seven publications report HSR to FA, mainly confirmed by the disappearance of symptoms after the withdrawal of FA from chemotherapy. Only two papers describe allergy testing. Due to the difficult diagnosis, patients usually receive several further cycles of chemotherapy with progressively more intense symptoms before the withdrawal of FA.

CASE PRESENTATION

Here we document two cases of HSR to FA, initially misattributed to oxaliplatin. The first patient described successive cycles with first back muscle pain, then chills and facial oedema and finally diffuse erythema with labial edema despite premedication. The allergy assessment highlighted high acute tryptase levels and intradermal tests positive for FA, pointing to an immunoglobulin E (IgE)-mediated mechanism. The second patient also had lower back muscle pain and chills in addition to tachycardia and desaturation during the administration of FA. Skin tests were negative and tryptase levels normal. After withdrawing FA, the symptoms did not recur, thus allowing the patient to continue chemotherapy. The mechanism of FA hypersensitivity is still unclear. The chronology of symptoms suggests an IgE-mediated mechanism that was not documented in the allergy assessment. A non-IgE-mediated mast cell/basophil activation could be involved, through complement activation or through Mas-related G protein-coupled receptors X2 (MRGPRX2) particularly.

CONCLUSIONS

These two cases of anaphylaxis to FA document the clinical manifestations associated with two different mechanisms of HSR. This paper provided the opportunity to review the limited literature on HSR to FA. Through these cases, we hope to draw the practitioner's attention to FA as a potential agent of severe hypersensitivity, especially if symptoms remain after withdrawing the most suspected chemotherapeutic agents. We want also to stress the importance of allergy testing.

Idiopathic Anaphylaxis? Analysis of Data from the Anaphylaxis Registry for West Pomerania Province, Poland

The most common causes of anaphylaxis, according to various authors and depending on the age of the studied groups, are: Hymenoptera venom, food, and medications. Unfortunately, we are not always able to indicate the cause of anaphylaxis. There are data in the literature where as many as 41% of all cases are idiopathic anaphylaxis. Since the introduction of new diagnostic methods such as molecular diagnostics (MD) in our centre, the percentage of idiopathic anaphylaxis in the Anaphylaxis Register has significantly decreased. The purpose of this study was to identify possible causes of idiopathic anaphylaxis in patients with a history of moderate to severe anaphylactic reactions. After using MD, the causative agent was found in another 29 people. The proportion of people with idiopathic anaphylaxis in the Registry decreased from 9.2% to 3.5%. There were no significant differences in the incidence, although men appear to be slightly more common in primary idiopathic anaphylaxis. The mean age of primary idiopathic anaphylaxis was 40 years, but this was as high as 51 for anaphylaxis with alpha-gal allergy. Exercise may or may not be present as a cofactor despite its established role, e.g., in wheat-dependent exercise-induced anaphylaxis (WDEIA). In most of the analyzed cases, i.e., 70%, the reaction took place within an hour. The longest time interval from exposure to the development of symptoms is in the case of alpha-gal allergy; in this analysis, it was at least 5 h after ingestion of the so-called "red meat". Patients are not aware of the disease, or further attacks cannot be prevented. As many as 80% had idiopathic anaphylaxis prior to visiting the centre, and 80% developed anaphylaxis after visiting the centre, which emphasizes the need to not stop the medical team in their search for the causes. As many as 93% of cases required medical intervention, of which adrenaline was used only in 34.5%, antihistamines in 86%, systemic glucocorticosteroids (sCS) in 75%, and fluids in 62% of cases. A total of 83% of patients received an emergency kit for self-administration. Idiopathic anaphylaxis can be resolved as known-cause anaphylaxis after a thorough medical history and, if possible, without exposing the patient after using appropriate, modern in vitro diagnostic methods, including molecular diagnostics. The diagnosis of idiopathic anaphylaxis should extend the diagnosis to include alpha-gal syndrome, LTP syndrome and WDEIA.

Integrative transcriptomic analysis in human and mouse model of anaphylaxis identifies gene signatures associated with cell movement, migration and neuroinflammatory signalling

Background

Anaphylaxis is an acute life-threatening allergic reaction and a concern at a global level; therefore, further progress in understanding the underlying mechanisms and more effective strategies for diagnosis, prevention and management are needed.

Objective

We sought to identify the global architecture of blood transcriptomic features of anaphylaxis by integrating expression data from human patients and mouse model of anaphylaxis.

Methods

Bulk RNA-sequencings of peripheral whole blood were performed in: i) 14 emergency department (ED) patients with acute anaphylaxis, predominantly to Hymenoptera venom, ii) 11 patients with peanut allergy undergoing double-blind, placebo-controlled food challenge (DBPCFC) to peanut, iii) murine model of IgE-mediated anaphylaxis. Integrative characterisation of differential gene expression, immune cell-type-specific gene expression profiles, and functional and pathway analysis was undertaken.

Results

1023 genes were commonly and significantly dysregulated during anaphylaxis in ED and DBPCFC patients; of those genes, 29 were also dysregulated in the mouse model. Cell-type-specific gene expression profiles showed a rapid downregulation of blood basophil and upregulation of neutrophil signature in ED and DBPCFC patients and the mouse model, but no consistent and/or significant differences were found for other blood cells. Functional and pathway analysis demonstrated that human and mouse blood transcriptomic signatures of anaphylaxis follow trajectories of upregulation of cell movement, migration and neuroinflammatory signalling, and downregulation of lipid activating nuclear receptors signalling.

Conclusion

Our study highlights the matched and extensive blood transcriptomic changes and suggests the involvement of discrete cellular components and upregulation of migration and neuroinflammatory pathways during anaphylaxis.

A comprehensive summary of disease variants implicated in metal allergy

Allergic disease represents one of the most prominent global public health crises of the 21^st century. Although many different substances are known to produce hypersensitivity responses, metals constitute one of the major classes of allergens responsible for a disproportionately large segment of the total burden of disease associated with allergy. Some of the most prevalent forms of metal allergy - including allergic contact dermatitis - are well-recognized; however, to our knowledge, a comprehensive review of the many unique disease variants implicated in human cases of metal allergy is not available within the current scientific literature. Consequently, the main goal in composing this review was to (1) generate an up-to-date reference document containing this information to assist in the efforts of lab researchers, clinicians, regulatory toxicologists, industrial hygienists, and other scientists concerned with metal allergy and (2) identify knowledge gaps related to disease. Accordingly, an extensive review of the scientific literature was performed - from which, hundreds of publications describing cases of metal-specific allergic responses in human patients were identified, collected, and analyzed. The information obtained from these articles was then used to compile an exhaustive list of distinctive dermal/ocular, respiratory, gastrointestinal, and systemic hypersensitivity responses associated with metal allergy. Each of these disease variants is discussed briefly within this review, wherein specific metals implicated in each response type are identified, underlying immunological mechanisms are summarized, and major clinical presentations of each reaction are described.Abbreviations: ACD: allergic contact dermatitis, AHR: airway hyperreactivity, ASIA: autoimmune/ autoinflammatory syndrome induced by adjuvants, BAL: bronchoalveolar lavage, CBD: chronic beryllium disease, CTCL: cutaneous T-cell lymphoma, CTL: cytotoxic T-Lymphocyte, DRESS: drug reaction with eosinophilia and systemic symptoms, GERD: gastro-esophageal reflux disease, GI: gastrointestinal, GIP: giant cell interstitial pneumonia, GM-CSF: granulocyte macrophage-colony stimulating factor, HMLD: hard metal lung disease, HMW: high molecular weight, IBS: irritable bowel syndrome, Ig: immunoglobulin, IL: interleukin, LMW: low molecular weight, PAP: pulmonary alveolar proteinosis, PPE: personal protective equipment, PRR: pathogen recognition receptor, SLE: systemic lupus erythematosus, SNAS: systemic nickel allergy syndrome, Th: helper T-cell, UC: ulcerative colitis, UV: ultraviolet.

Allergic Reactions to COVID-19 Vaccines: Risk Factors, Frequency, Mechanisms and Management

Conventional vaccines have been widely studied, along with their risk of causing allergic reactions. These generally consist of mild local reactions and only rarely severe anaphylaxis. Although all the current COVID-19 vaccines marketed in Europe have been shown to be safe overall in the general population, early post-marketing evidence has shown that mRNA-based vaccines using novel platforms (i.e., lipid nanoparticles) were associated with an increased risk of severe allergic reactions as compared to conventional vaccines. In this paper we performed an updated literature review on frequency, risk factors, and underlying mechanisms of COVID-19 vaccine-related allergies by searching MEDLINE and Google Scholar databases. We also conducted a qualitative search on VigiBase and EudraVigilance databases to identify reports of "Hypersensitivity" and "Anaphylactic reaction" potentially related to COVID-19 vaccines (Comirnaty, Spikevax, Vaxzevria and COVID-19 Janssen Vaccine), and in EudraVigilance to estimate the reporting rates of "Anaphylactic reaction" and "Anaphylactic shock" after COVID-19 vaccination in the European population. We also summarized the scientific societies' and regulatory agencies' recommendations for prevention and management of COVID-19 vaccine-related allergic reactions, especially in those with a history of allergy.

Same-Day Desensitization in Patients Who Experience Their First Reaction to a Platin Agent at the Oncology Day Unit: A Pilot Study to Safely Include This Technique Within the Multidisciplinary Pathways for the Diagnosis & Management of Hypersensitivity to Platin Agents

One of the main objectives when assessing patients who react to antineoplastics must be to ensure that they receive the required treatments without delay. From January to July 2021, at the Allergy Department at the Provincial University Consortium Hospital a pilot study was performed in which those patients suspected of having suffered a type I hypersensitivity reaction (grade 1 or 2) following Brown's anaphylaxis severity grading to a platin agent at the Provincial University Consortium oncology day unit, and once the reaction was properly treated and completely resolved, were subjected to a new procedure named as Same-Day Desensitization, which consists in the reintroduction and administration of full chemotherapy dose by allergists on the same day of the reaction by following the 1 bag/10 step protocol, looking forwards to systematize same-day reexposure using Same-Day Desensitization, doing it in the safest way possible. In total, 9 oncological patients suspected of having suffered a type I hypersensitivity reaction (grade 1 or 2) to a platin agent received total dose administration the same day of the initial reaction by following Same-Day Desensitization 1 bag/10 step protocol, without presenting further reactions. The manuscript describes a new approach in the use of Rapid Drug Desensitizations in reactive oncologic patients in treatment with platin agents, presenting the first 9 cases of oncologic patients who have been submitted to this procedure.

Adult anaphylaxis: A state-of-the-art review

Anaphylaxis is the most severe among acute allergic diseases and potentially life threatening. Despite its increasing frequency and related burden, it remains often underdiagnosed and improperly managed. Its multisystemic involvement, protean clinical manifestations and its rapid onset are contributory factors. In recent years new acquisitions have shed light into its pathogenesis pathways (and related biomarkers), triggers, factors increasing its severity, along with peculiar clinical manifestations. These breakthrough discoveries have contributed to phenotyping and endotyping this disease, possibly paving the way to a personalized approach which is not available at present. Moreover, to disseminate awareness and standardize diagnostic criteria and management practices, several guidelines and consensus reports, albeit mainly intended for specialist care, have been issued. We here discuss the latest issues in the field of anaphylaxis from the perspective of the emergency and/or internal medicine physician, so to improve its early recognition and treatment in the acute setting and favor allergology referral to implement therapeutical and preventive strategies, such as allergen identification in unclear cases and desensitizing therapies when available (e.g., for Hymenoptera venom allergy).

Characterization of hypersensitivity reactions to polysulfone hemodialysis membranes

BACKGROUND

In recent years, cases have been reported in which unexpected systemic hypersensitivity reactions occurred in patients dialyzed with polysulfone- or polyethersulfone-biocompatible membranes in the absence of other risk factors. The pathomechanisms involved in these reactions are largely unknown.

OBJECTIVE

To characterize hypersensitivity reactions to polysulfone hemodialysis using clinical and laboratory data and to identify biomarkers suitable for endotype identification and diagnosis.

METHODS

We prospectively collected data from 29 patients with suspected hypersensitivity reactions to polysulfone hemodialysis membranes. Clinical laboratory parameters such as tryptase, blood cell counts, and complement levels were recorded. Acute samples were obtained from 18 cases for the ex vivo assessment of basophil activation by flow cytometry analysis of CD63, CD203, and FcεRI cell membrane expression. Serum cytokines and anaphylatoxin concentrations were evaluated in 16 cases by Luminex and cytometric bead array analysis.

RESULTS

Tryptase was elevated during the acute reaction in 4 cases. Evidence of basophil activation was obtained in 10 patients. Complement activation was found in only 2 cases. However, C5a serum levels tended to increase during the acute reaction in those patients with hypoxemia. Significantly higher serum levels of interleukin-6 were observed during the acute reactions to polysulfone hemodialysis (P = .0103).

CONCLUSION

Based on biomarker analysis, various endotypes were identified, including type I-like (with the involvement of mast cells or basophils), complement, and cytokine (interleukin-6) release-related reactions, with some patients showing mixed reactions. Further research is needed to unravel the exact mechanisms involved in the activation of these cellular and molecular pathways.

Acute Urticaria and Anaphylaxis: Differences and Similarities in Clinical Management

Acute urticaria is a common condition that presents with wheals and/or angioedema. However, these symptoms are also frequent in anaphylaxis, a life-threatening reaction that should be immediately diagnosed and treated. In both, mast cells play a central role in the physiopathology. Causes and triggers of acute urticaria and anaphylaxis are similar in general, but some peculiarities can be observed. The diagnostic approach may differ, accordingly to the condition, suspicious causes, age groups and regions. Adrenaline is the first-line treatment for anaphylaxis, but not for acute urticaria, where H1-antihistamines are the first choice. In this paper, we review the main aspects, similarities and differences regarding definitions, mechanisms, causes, diagnosis and treatment of acute urticaria and anaphylaxis.

Pathophysiological, Cellular, and Molecular Events of the Vascular System in Anaphylaxis

Anaphylaxis is a systemic hypersensitivity reaction that can be life threatening. Mechanistically, it results from the immune activation and release of a variety of mediators that give rise to the signs and symptoms of this pathological event. For years, most of the research in anaphylaxis has focused on the contribution of the immune component. However, approaches that shed light on the participation of other cellular and molecular agents are necessary. Among them, the vascular niche receives the various signals (e.g., histamine) that elicit the range of anaphylactic events. Cardiovascular manifestations such as increased vascular permeability, vasodilation, hypotension, vasoconstriction, and cardiac alterations are crucial in the pathophysiology of anaphylaxis and are highly involved to the development of the most severe cases. Specifically, the endothelium, vascular smooth muscle cells, and their molecular signaling outcomes play an essential role downstream of the immune reaction. Therefore, in this review, we synthesized the vascular changes observed during anaphylaxis as well as its cellular and molecular components. As the risk of anaphylaxis exists both in clinical procedures and in routine life, increasing our knowledge of the vascular physiology and their molecular mechanism will enable us to improve the clinical management and how to treat or prevent anaphylaxis.

Key Message

Anaphylaxis, the most severe allergic reaction, involves a variety of immune and non-immune molecular signals that give rise to its pathophysiological manifestations. Importantly, the vascular system is engaged in processes relevant to anaphylactic events such as increased vascular permeability, vasodilation, hypotension, vasoconstriction, and decreased cardiac output. The novelty of this review focuses on the fact that new studies will greatly improve the understanding of anaphylaxis when viewed from a vascular molecular angle and specifically from the endothelium. This knowledge will improve therapeutic options to treat or prevent anaphylaxis.

Applying lessons learned from nanomedicines to understand rare hypersensitivity reactions to mRNA-based SARS-CoV-2 vaccines

After over a billion of vaccinations with messenger RNA-lipid nanoparticle (mRNA-LNP) based SARS-CoV-2 vaccines, anaphylaxis and other manifestations of hypersensitivity can be considered as very rare adverse events. Although current recommendations include avoiding a second dose in those with first-dose anaphylaxis, the underlying mechanisms are unknown; therefore, the risk of a future reaction cannot be predicted. Given how important new mRNA constructs will be to address the emergence of new viral variants and viruses, there is an urgent need for clinical approaches that would allow a safe repeated immunization of high-risk individuals and for reliable predictive tools of adverse reactions to mRNA vaccines. In many aspects, anaphylaxis symptoms experienced by the affected vaccine recipients resemble those of infusion reactions to nanomedicines. Here we share lessons learned over a decade of nanomedicine research and discuss the current knowledge about several factors that individually or collectively contribute to infusion reactions to nanomedicines. We aim to use this knowledge to inform the SARS-CoV-2 lipid-nanoparticle-based mRNA vaccine field.

Serological profiling reveals hsa-miR-451a as a possible biomarker of anaphylaxis

Background

There is a need to support the diagnosis of anaphylaxis by objective markers. miRNAs are promising noncoding RNA species that may serve as serological biomarkers, but their use in diagnosing anaphylaxis has not been systematically studied to our knowledge. We aimed to comprehensively investigate serum biomarker profiles (proteins, lipids, and miRNAs) to support the diagnosis of anaphylaxis.

Methods

Adult patients admitted to the emergency room with a diagnosis of anaphylaxis (<3 hours) were included. Blood samples were taken upon emergency room arrival and 1 month later.

Results

Next-generation sequencing of 18 samples (6 patients with anaphylaxis in both acute and nonacute condition, for 12 total samples, and 6 healthy controls) identified hsa-miR-451a to be elevated during anaphylaxis, which was verified by quantitative real-time PCR in the remaining cohort. The random forest classifier enabled us to classify anaphylaxis with high accuracy using a composite model. We identified tryptase, 9α,11β-PGF2, apolipoprotein A1, and hsa-miR-451a as serological biomarkers of anaphylaxis. These predictors qualified as serological biomarkers individually but performed better in combination.

Conclusion

Unexpectedly, hsa-miR-451a was identified as the most relevant biomarker in our data set. We were also able to distinguish between patients with a history of anaphylaxis and healthy individuals with higher accuracy than any other available model. Future studies will need to verify miRNA biomarker utility in real-life clinical settings.

Funding

This work is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) as part of the clinical research unit (CRU339): Food Allergy and Tolerance (FOOD@) (project number 409525714) and a grant to MW (Wo541-16-2, project number 264921598), as well as by FOOD@ project numbers 428094283 and 428447634.

Wilderness Medical Society Clinical Practice Guidelines on Anaphylaxis

The Wilderness Medical Society convened a panel to review the literature and develop evidence-based clinical practice guidelines on the treatment of anaphylaxis, with an emphasis on a field-based perspective. The review also included literature regarding the definition, epidemiology, clinical manifestations, and prevention of anaphylaxis. The increasing prevalence of food allergies in the United States raises concern for a corresponding rise in the incidence of anaphylaxis. Intramuscular epinephrine is the primary treatment for anaphylaxis and should be administered before adjunctive treatments such as antihistamines, corticosteroids, and inhaled β agonists. For outdoor schools and organizations, selecting a method to administer epinephrine in the field is based on considerations of cost, safety, and first responder training, as well as federal guidelines and state-specific laws.

Converter Phenotype: A New Profile That Is Not Exclusive to Taxanes

Introduction: Phenotype I hypersensitivity reactions are the most commonly reported drug reactions; however, precision medicine has made it possible to characterize new phenotypes. A recent communication proposed the existence of a “converter phenotype,” which would affect patients who present non-immediate hypersensitivity reactions and in subsequent exposures develop immediate hypersensitivity reactions. This study aimed to describe the clinical characteristics of converter phenotype reactions and their evolution during desensitization to chemotherapeutic drugs and monoclonal antibodies.

Methods: We retrospectively reviewed our database of patients undergoing desensitization to chemotherapy or biological agents and selected those with a converter phenotype. Demographic and clinical characteristics of the patients, the results of skin tests, tryptase and IL-6 levels, and desensitization outcomes were assessed.

Results: Of 116 patients evaluated, 12 (10.3%) were identified as having a converter phenotype. The median interval between drug exposure and reaction was 90.6 h (range 8-288 h). After the conversion, phenotype I was the most frequent (58.3%), followed by cytokine release reactions (33.3%). Fifty-one desensitizations were undertaken and all treatments completed, with 10 (19.6%) breakthrough reactions. No new changes in the phenotype were detected.

Conclusions: The symptoms of non-immediate drug hypersensitivity reactions may indicate the need for an early allergological evaluation to assess the risk of future immediate drug reactions. Clinical characteristics, skin test results, and biomarkers can help predict responses to rapid drug desensitization, guiding clinicians on how to optimize therapy delivery while maintaining patient safety.

Cytokine release syndrome – a unique entity of Augmentin hypersensitivity reaction

Cytokine release syndrome (CRS) is a type of hypersensitivity reaction which has been previously described with chemotherapy and monoclonal antibodies, but not with antibiotics. We present 2 pediatric cases of Amoxicillin/Clavulanic acid (Augmentin) anaphylaxis resembling CRS. Both our patients presented during the index reaction with symptoms suggestive of an acute systemic inflammatory response mimicking sepsis. Their symptomology was reproducible at drug provocation test as anaphylaxis, but with suboptimal response to intramuscular adrenaline. Their infective workups were unremarkable and illnesses followed a self-limiting course. All these point towards a severe hypersensitivity reaction resembling CRS.

New Biomarkers in Anaphylaxis (Beyond Tryptase)

Purpose of Review

The purpose of this review is to provide a better understanding of anaphylaxis pathophysiology and describe the underlying mechanisms, effector cells, and the potential biomarkers involved depending on the anaphylaxis endotypes.

Recent Findings

New insight into the potential relevance of pathways others than IgE-dependent anaphylaxis has been unraveled, as well as other biomarkers than tryptase, such as the role of platelet activation factor, basogranulin, dipeptidyl peptidase I, CCL-2, and other cytokines.

Summary

Gaining knowledge of all the mediators and cellular activation/communication pathways involved in each endotype of anaphylaxis will allow the application of precision medicine in patients with anaphylactic reactions, providing insights to the most appropriate approach in each case and helping to stratify severity and risk prediction.

Detection of Lectin Protein Allergen of Kidney Beans (Phaseolus vulgaris L.) and Desensitization Food Processing Technology

With the increase of food allergy events related to not properly cooked kidney beans (Phaseolus vulgaris L.), more and more researchers are paying attention to the sensitization potential of lectin, one of the major storage and defensive proteins with the specific carbohydrate-binding activity. The immunoglobulin E (IgE), non-IgE, and mixed allergic reactions induced by the lectins were inducted in the current paper, and the detection methods of kidney bean lectin, including the purification strategies, hemagglutination activity, specific polysaccharide or glycoprotein interactions, antibody combinations, mass spectrometry methods, and allergomics strategies, were summarized, while various food processing aspects, such as the physical thermal processing, physical non-thermal processing, chemical modifications, and biological treatments, were reviewed in the potential of sensitization reduction. It might be the first comprehensive review on lectin allergen detection from kidney bean and the desensitization strategy in food processing and will provide a basis for food safety control.

COVID-19 mRNA vaccine allergy

PURPOSE OF REVIEW

A known history of a severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine is the only contraindication to coronavirus disease 2019 (COVID-19) mRNA vaccination. It is important for pediatricians to understand the likelihood of an allergic reaction to COVID-19 mRNA vaccines, including its excipients.

RECENT FINDINGS

Episodes concerning for anaphylaxis were immediately reported following early administration of COVID-19 mRNA vaccines to adults. Although allergic type symptoms were reported equally in recipients of placebos and test vaccines in phase 3 clinical trials, post-authorization prospective studies state that 0.2-2% of vaccine recipients have experienced allergic reactions. Subsequent allergy testing of affected individuals has focused largely on evaluation of allergic sensitization to a novel vaccine excipient, polyethylene glycol (PEG). PEG is a polymer incorporated in numerous pharmaceutical products because of its favorable, inert properties. The results of allergy testing in adults to date indicate that IgE mediated anaphylaxis to PEG allergy is rarely identified after COVID-19 mRNA vaccine reactions. Numerous individuals with presumed anaphylaxis have tolerated a second vaccine after evaluation and testing by an allergist, suggesting either misdiagnosis or a novel immune mechanism.

SUMMARY

Confirmed anaphylactic reactions to COVID-19 mRNA vaccines are rare, likely due to a lack of preexisting IgE against the vaccine components, including PEG.

Dimerized Translationally Controlled Tumor Protein-Binding Peptide 2 Attenuates Systemic Anaphylactic Reactions Through Direct Suppression of Mast Cell Degranulation

Dimerized translationally controlled tumor protein (dTCTP) amplifies allergic responses through activation of several types of immune cells and release of inflammatory mediators. In particular, dTCTP plays an important role in histamine release by triggering mast cells and has been proposed as a target in the treatment of allergic diseases. dTCTP-binding peptide 2 (dTBP2) is known to attenuate severe allergic rhinitis and asthma through inhibition of dTCTP activity on airway epithelial cells and T cells; however, it is unclear whether dTBP2 affects mast cell function and mast cell disease. In this study, we explored the effects of dTBP2 on mast cell degranulation and allergen-induced anaphylactic reactions. We found that bacterial product lipopolysaccharide increased the expression of dTCTP in mast cells and rapidly released dTCTP by the mast cell stimulator compound 48/80. Interestingly, the released dTCTP further promoted mast cell degranulation in an autocrine activation manner and increased calcium mobilization in mast cells, which is essential for degranulation. Furthermore, dTBP2 directly and dose-dependently inhibited in vitro mast cell degranulation enhanced by compound 48/80, suggesting a direct and potent anti-anaphylactic activity of dTBP2. dTBP2 also significantly suppressed the dTCTP-induced degranulation and histamine release through inhibition of the p38 MAPK signaling pathway and suppression of lysosomal expansion and calcium mobilization in mast cells. More importantly, in vivo administration of dTBP2 decreased mortality and significantly attenuated histamine release and inflammatory cytokine production in compound 48/80-induced systemic anaphylactic reactions. These results suggest that dTBP2 is beneficial for the control of anaphylaxis with increased dTCTP.

Compound Kushen Injection Induces Immediate Hypersensitivity Reaction Through Promoting the Production of Platelet-Activating Factor via de Novo Pathway

Compound Kushen Injection (CKI) is a bis-herbal formulation extracted from Kushen (Radix Sophorae Flavescentis) and Baituling (Rhizoma Heterosmilacis Yunnanensis). Clinically, it is used as the adjuvant treatment of cancer. However, with the increased application, the cases of immediate hypersensitivity reactions (IHRs) also gradually rise. In this study, we investigated the underlying mechanism(s) and active constituent(s) for CKI-induced IHRs in experimental models. The obtained results showed that CKI did not elevate serum total IgE (tIgE) and mouse mast cell protease 1 (MMCP1) after consecutive immunization for 5 weeks, but could induce Evans blue extravasation (local) and cause obvious hypothermia (systemic) after a single injection. Further study showed that alkaloids in Kushen, especially matrine, were responsible for CKI-induced IHRs. Mechanism study showed that various platelet-activating factor (PAF) receptor antagonists could significantly counter CKI-induced IHRs locally or systemically. In cell system, CKI was able to promote PAF production in a non-cell-selective manner. In cell lysate, the effect of CKI on PAF production became stronger and could be abolished by blocking de novo pathway. In conclusion, our study identifies, for the first time, that CKI is a PAF inducer. It causes non-immunologic IHRs, rather than IgE-dependent IHRs, by promoting PAF production through de novo pathway. Alkaloids in Kushen, especially matrine, are the prime culprits for IHRs. Our findings may provide a potential approach for preventing and treating CKI-induced IHRs.

Recent update on the management of anaphylaxis

Anaphylaxis is a life-threatening systemic allergic reaction presenting various clinical manifestations. Its prevalence has increased in almost all age groups and both sexes. Food, venom, and drugs are major causes in both children and adults; a higher prevalence of food-induced anaphylaxis is noted in children, while a higher prevalence of drug-induced anaphylaxis is noted in adults. The pathogenic mechanism is mediated by immunologic and nonimmunologic mechanisms, where mast cells and basophils are key cells that release mediators. A diagnosis of anaphylaxis is mainly based on clinical symptoms and physical findings; however, an increased serum tryptase level is a useful biomarker. Epinephrine is the first-line drug to treat acute symptoms, and an epinephrine auto-injector should be prescribed for each patient. Antihistamines and systemic corticosteroids are used to relieve symptoms. This review updates current issues in the management of anaphylaxis as well as the new guidelines for proper diagnosis and treatment.

[Diagnostic and therapeutic approach to anaphylaxis in childhood and adolescence]

Anaphylaxis is a suddenly occurring potentially life-threatening systemic allergic reaction. In childhood, food allergens play a major role but insect stings and drugs are also potential triggers. The symptoms appear in minutes up to few hours on the skin, airways, gastrointestinal tract and/or the cardiovascular system. Intramuscular adrenaline is the drug of first choice due to its rapid effectiveness and its low side effect potential. A detailed patient history and the determination of potential IgE antibodies must be carried out to identify the triggers. The register for anaphylaxis has improved knowledge on epidemiology. An education in anaphylaxis is useful for every patient as well as parents and caregivers. Allergen-specific immunotherapy is currently the only causal treatment option; however, at the present time it is only available for insect bites and peanut allergy.

Risk factors of beta-lactam anaphylaxis in Korea: A 6-year multicenter retrospective adult case-control study

Background

Beta-lactams (BLs) are commonly used antibiotics and leading causative agents of drug-induced anaphylaxis. Few studies on the culprit drugs and risk factors of BL-induced anaphylaxis are available. Our goal was to evaluate the culprit drugs and compare the risk factors in patients with BL-induced anaphylaxis to matched tolerant controls in a hospital setting.

Methods

We retrospectively enrolled all patients who developed anaphylaxis from intravenous BL during hospitalization from 9 Korean hospitals. We compared clinical parameters between patients with BL-induced anaphylaxis and 4-fold BL-tolerant controls matched by age, sex, BL use, and the purpose of BL administration.

Results

Seventy-four cases of BL-induced anaphylaxis and 296 BL-tolerant controls were enrolled. Cephalosporin accounted for 77% of total BL-induced anaphylaxis, and the top derivatives were ceftriaxone (23.0%), cefazedone (10.8%), and cefbuperazone (9.5%). Among penicillin derivatives, piperacillin (16.2%) was the most common, followed by ampicillin (2.7%). History of drug allergy (odds ratio [OR], 19.91; 95% confidence interval [CI] 5.33–74.44), previous exposure to the causative BL (OR, 7.71; 95% CI, 1.62–36.76), and concurrent administration of angiotensin-converting enzyme inhibitors (ACEIs) (OR, 5.97; 95% CI, 1.28–27.91) were independent risk factors associated with BL-induced anaphylaxis. Food allergy (OR, 13.93; 95% CI 1.31–148.9) and previous exposure to BL (OR, 6.59; 95% CI, 1.30–33.31) were identified as risk factors for cephalosporin-induced anaphylaxis.

Conclusions

To prevent BL-induced anaphylaxis, attention should be paid to histories of drug or food allergy, previous exposure to BLs, and ACEI use. The risk factors and clinical outcomes might vary according to the BL classes.

Influenza Viruses: Innate Immunity and mRNA Vaccines

The innate immune system represents the first line of defense against influenza viruses, which cause severe inflammation of the respiratory tract and are responsible for more than 650,000 deaths annually worldwide. mRNA vaccines are promising alternatives to traditional vaccine approaches due to their safe dosing, low-cost manufacturing, rapid development capability, and high efficacy. In this review, we provide our current understanding of the innate immune response that uses pattern recognition receptors to detect and respond to mRNA vaccination. We also provide an overview of mRNA vaccines, and discuss the future directions and challenges in advancing this promising therapeutic approach.

Characterization of anaphylaxis reveals different metabolic changes depending on severity and triggers

BACKGROUND

Despite the increasing incidence of anaphylaxis, its underlying molecular mechanisms and biomarkers for appropriate diagnosis remain undetermined. The rapid onset and potentially fatal outcome in the absence of managed treatment prevent its study. Up today, there are still no known biomarkers that allow an unequivocal diagnosis. Therefore, the aim of this study was to explore metabolic changes in patients suffering anaphylactic reactions depending on the trigger (food and/or drug) and severity (moderate and severe) in a real-life set-up.

METHODS

Eighteen episodes of anaphylaxis, one per patient, were analysed. Sera were collected during the acute phase (T1), the recovery phase (T2) and around 2-3 months after the anaphylactic reaction (T0: basal state). Reactions were classified following an exhaustive allergological evaluation for severity and trigger. Sera samples were analysed using untargeted metabolomics combining liquid chromatography coupled to mass spectrometry (LC-MS) and proton nuclear magnetic resonance spectroscopy (¹ H-NMR).

RESULTS

'Food T1 vs T2' and 'moderate T1 vs T2' anaphylaxis comparisons showed clear metabolic patterns during the onset of an anaphylactic reaction, which differed from those induced by drugs, food + drug or severe anaphylaxis. Moreover, the model of food anaphylaxis was able to distinguish the well-characterized IgE (antibiotics) from non-IgE-mediated anaphylaxis (nonsteroidal anti-inflammatory drugs), suggesting a differential metabolic pathway associated with the mechanism of action. Metabolic differences between 'moderate vs severe' at the acute phase T1 and at basal state T0 were studied. Among the altered metabolites, glucose, lipids, cortisol, betaine and oleamide were observed altered.

CONCLUSIONS

The results of this exploratory study provide the first evidence that different anaphylactic triggers or severity induce differential metabolic changes along time or at specific time-point, respectively. Besides, the basal status T0 might identify high-risk patients, thus opening new ways to understand, diagnose and treat anaphylaxis.

Mechanisms Governing Anaphylaxis: Inflammatory Cells, Mediators, Endothelial Gap Junctions and Beyond

Anaphylaxis is a severe, acute, life-threatening multisystem allergic reaction resulting from the release of a plethora of mediators from mast cells culminating in serious respiratory, cardiovascular and mucocutaneous manifestations that can be fatal. Medications, foods, latex, exercise, hormones (progesterone), and clonal mast cell disorders may be responsible. More recently, novel syndromes such as delayed reactions to red meat and hereditary alpha tryptasemia have been described. Anaphylaxis manifests as sudden onset urticaria, pruritus, flushing, erythema, angioedema (lips, tongue, airways, periphery), myocardial dysfunction (hypovolemia, distributive or mixed shock and arrhythmias), rhinitis, wheezing and stridor. Vomiting, diarrhea, scrotal edema, uterine cramps, vaginal bleeding, urinary incontinence, dizziness, seizures, confusion, and syncope may occur. The traditional (or classical) pathway is mediated via T cells, Th2 cytokines (such as IL-4 and 5), B cell production of IgE and subsequent crosslinking of the high affinity IgE receptor (FcεRI) on mast cells and basophils by IgE-antigen complexes, culminating in mast cell and basophil degranulation. Degranulation results in the release of preformed mediators (histamine, heparin, tryptase, chymase, carboxypeptidase, cathepsin G and tumor necrosis factor alpha (TNF-α), and of de novo synthesized ones such as lipid mediators (cysteinyl leukotrienes), platelet activating factor (PAF), cytokines and growth factors such as vascular endothelial growth factor (VEGF). Of these, histamine, tryptase, cathepsin G, TNF-α, LTC₄, PAF and VEGF can increase vascular permeability. Recent data suggest that mast cell-derived histamine and PAF can activate nitric oxide production from endothelium and set into motion a signaling cascade that leads to dilatation of blood vessels and dysfunction of the endothelial barrier. The latter, characterized by the opening of adherens junctions, leads to increased capillary permeability and fluid extravasation. These changes contribute to airway edema, hypovolemia, and distributive shock, with potentially fatal consequences. In this review, besides mechanisms (endotypes) underlying IgE-mediated anaphylaxis, we also provide a brief overview of IgG-, complement-, contact system-, cytokine- and mast cell-mediated reactions that can result in phenotypes resembling IgE-mediated anaphylaxis. Such classifications can lead the way to precision medicine approaches to the management of this complex disease.