Epidemiology, Mechanisms, and Diagnosis of Drug-Induced Anaphylaxis

Trust but Verify: Lessons Learned for the Application of AI to Case-Based Clinical Decision-Making From Postmarketing Drug Safety Assessment at the US Food and Drug Administration

Adverse drug reactions are a common cause of morbidity in health care. The US Food and Drug Administration (FDA) evaluates individual case safety reports of adverse events (AEs) after submission to the FDA Adverse Event Reporting System as part of its surveillance activities. Over the past decade, the FDA has explored the application of artificial intelligence (AI) to evaluate these reports to improve the efficiency and scientific rigor of the process. However, a gap remains between AI algorithm development and deployment. This viewpoint aims to describe the lessons learned from our experience and research needed to address both general issues in case-based reasoning using AI and specific needs for individual case safety report assessment. Beginning with the recognition that the trustworthiness of the AI algorithm is the main determinant of its acceptance by human experts, we apply the Diffusion of Innovations theory to help explain why certain algorithms for evaluating AEs at the FDA were accepted by safety reviewers and others were not. This analysis reveals that the process by which clinicians decide from case reports whether a drug is likely to cause an AE is not well defined beyond general principles. This makes the development of high performing, transparent, and explainable AI algorithms challenging, leading to a lack of trust by the safety reviewers. Even accounting for the introduction of large language models, the pharmacovigilance community needs an improved understanding of causal inference and of the cognitive framework for determining the causal relationship between a drug and an AE. We describe specific future research directions that underpin facilitating implementation and trust in AI for drug safety applications, including improved methods for measuring and controlling of algorithmic uncertainty, computational reproducibility, and clear articulation of a cognitive framework for causal inference in case-based reasoning.

Anaphylaxis and Severe Disseminated Intravascular Coagulation Due to Remdesivir

A 69-year-old woman suffering with multiple myeloma developed coronavirus disease 2019 (COVID-19). Shortly after administration of remdesivir, she presented with symptoms of facial flushing, wheezing, and hypoxemia. Subsequently, thrombocytopenia and hypofibrinogenemia rapidly manifested, leading to a diagnosis of enhanced fibrinolytic-type disseminated intravascular coagulopathy (DIC). This clinical presentation was considered an immediate hypersensitivity reaction with associated coagulation abnormalities induced by remdesivir. Although remdesivir is generally considered safe and efficacious in the treatment of COVID-19, physicians should remain vigilant regarding the potential for severe adverse events associated with this medication.

The Application of Knowledge-Based Clinical Decision Support Systems to Detect Antibiotic Allergy

Prevention of drug allergies is important for patient safety. The objective of this study was to evaluate the outcomes of antibiotic allergy-checking clinical decision support system (CDSS), K-CDSTM. A retrospective chart review study was performed in 29 hospitals and antibiotic allergy alerts data were collected from May to August 2022. A total of 15,535 allergy alert cases from 1586 patients were reviewed. The most frequently prescribed antibiotics were cephalosporins (48.5%), and there were more alerts of potential cross-reactivity between beta-lactam antibiotics than between antibiotics with the same ingredients or of the same class. Regarding allergy symptoms, dermatological disorders were the most common (38.8%), followed by gastrointestinal disorders (28.4%). The 714 cases (4.5%) of immune system disorders included 222 cases of anaphylaxis and 61 cases of severe cutaneous adverse reactions. Alerts for severe symptoms were reported in 6.4% of all cases. This study confirmed that K-CDS can effectively detect antibiotic allergies and prevent the prescription of potentially allergy-causing antibiotics among patients with a history of antibiotic allergies. If K-CDS is expanded to medical institutions nationwide in the future, it can prevent an increase in allergy recurrence related to drug prescriptions through cloud-based allergy detection CDSSs.

Biomarkers of immediate drug hypersensitivity

Immediate drug hypersensitivity reactions (IDHRs) are a burden for patients and the health systems. This problem increases when taking into account that only a small proportion of patients initially labelled as allergic are finally confirmed after an allergological workup. The diverse nature of drugs involved will imply different interactions with the immunological system. Therefore, IDHRs can be produced by a wide array of mechanisms mediated by the drug interaction with specific antibodies or directly on effector target cells. These heterogeneous mechanisms imply an enhanced complexity for an accurate diagnosis and the identification of the phenotype and endotype at early stages of the reaction is of vital importance. Currently, several endophenotypic categories (type I IgE/non-IgE, cytokine release, Mast-related G-protein coupled receptor X2 (MRGPRX2) or Cyclooxygenase-1 (COX-1) inhibition and their associated biomarkers have been proposed. A precise knowledge of endotypes will permit to discriminate patients within the same phenotype, which is crucial in order to personalise diagnosis, future treatment and prevention to improve the patient's quality of life.

Changing patterns in the epidemiology of drug allergy

Drug allergy (DA) remains a complex and unaddressed problem worldwide that often deprives patients of optimal medication choices and places them at risk for life-threatening reactions. Underdiagnosis and overdiagnosis are common and due to the lack of standardized definitions and biomarkers. The true burden of DA is unknown, and recent efforts in data gathering through electronic medical records are starting to provide emerging patterns around the world. Ten percent of the general population engaged in health care claim to have a DA, and the most common label is penicillin allergy. Up to 20% of emergency room visits for anaphylaxis are due to DA and 15%-20% of hospitalized patients report DA. It is estimated that DA will increase based on the availability and use of new and targeted antibiotics, vaccines, chemotherapies, biologicals, and small molecules, which are aimed at improving patient's options and quality of life. Global and regional variations in the prevalence of diseases such as human immunodeficiency virus and mycobacterial diseases, and the drugs used to treat these infections have an impact on DA. The aim of this review is to provide an update on the global impact of DA by presenting emerging data on drug epidemiology in adult and pediatric populations.

"Antibiotic hypersensitivity reactions in Cystic Fibrosis: A thorough inspection on a stumbling block in patient care"

One hurdle in the management of CF, a disease characterized by progressive endobronchial infection, is the presence of hypersensitivity reactions to antimicrobials due to prolonged and repetitive treatment courses. The aim of this review is to compile existing data and provide insight to medical professionals on a long-debated topic for optimum patient care. Clinical studies were inducted from the last 15 years and filtered based on their relativity to drug hypersensitivity reactions (DHRs), antibiotics and CF. After completing the selection process, 10 clinical studies were thoroughly examined. The most frequent antibiotic group related to DHRs were beta-lactams. Frequency of the most common overall type of reaction (immediate or nonimmediate) differed among clinical studies. Although severe reactions seem rare comparatively, they do occur during and even after completion of treatment regimens. The prevalence of true drug allergies should be confirmed using a variety of tests available, however, should not be confused with overall DHR rates. Genetic mutations, gender and lifetime antibiotic dose were not related with an increased risk for DHR development. On the contrary, the most important factor according to most studies was the cumulative antimicrobial dose in a given period of time, especially when delivered parenterally. DHRs are an indisputable problem in the management of CF patients. Understanding possible risk factors and increased awareness is vital in both hospital and outpatient settings as early detection can decrease the severity of the reactions.

Evaluation of the Regulatory Required Post-Authorization Safety Study for Propacetamol: Nested Case-Control and Case-Time-Control Studies

PURPOSE

Following the withdrawal of propacetamol in Europe owing to safety issues, the regulatory authority of South Korea requested a post-marketing surveillance study to investigate its safety profile.

MATERIALS AND METHODS

We conducted nested case-control and case-time-control (CTC) analyses of cases and controls identified for outcomes of interest, including anaphylaxis, thrombosis, and Stevens-Johnson syndrome (SJS), using the claims database of South Korea, 2010-2019. Risk-set sampling was used to match each case with up to 10 controls for age, sex, cohort entry date, and follow-up duration. Exposure to anaphylaxis, thrombosis, and SJS was assessed within 7, 90, and 30 days of the index date, respectively. We calculated odds ratios (OR) with 95% confidence intervals (CIs) using conditional logistic regression to assess the risk of outcomes associated with propacetamol.

RESULTS

We identified cases of anaphylaxis (n=61), thrombosis (n=95), and SJS (n=1) and matched them to controls (173, 268, and 4, respectively). In the nested case-control analysis, the ORs for anaphylaxis and SJS were inestimable given the small number of propacetamol users during the risk period; meanwhile, the OR for thrombosis was 1.60 (95% CI 0.71-3.62). In the CTC design, the effect estimate was only estimated for thrombosis (OR 0.56, 95% CI 0.09-3.47).

CONCLUSION

In both nested case-control and CTC analyses, propacetamol was not associated with an increased risk of anaphylaxis, thrombosis, or SJS. The findings from this study, which used routinely collected clinical data, provide reassuring real-world evidence regarding the safety of propacetamol in a nationwide population to support regulatory decision-making.

Anaphylaxis: A 2023 practice parameter update

This practice parameter update focuses on 7 areas in which there are new evidence and new recommendations. Diagnostic criteria for anaphylaxis have been revised, and patterns of anaphylaxis are defined. Measurement of serum tryptase is important for diagnosis of anaphylaxis and to identify underlying mast cell disorders. In infants and toddlers, age-specific symptoms may differ from older children and adults, patient age is not correlated with reaction severity, and anaphylaxis is unlikely to be the initial reaction to an allergen on first exposure. Different community settings for anaphylaxis require specific measures for prevention and treatment of anaphylaxis. Optimal prescribing and use of epinephrine autoinjector devices require specific counseling and training of patients and caregivers, including when and how to administer the epinephrine autoinjector and whether and when to call 911. If epinephrine is used promptly, immediate activation of emergency medical services may not be required if the patient experiences a prompt, complete, and durable response. For most medical indications, the risk of stopping or changing beta-blocker or angiotensin-converting enzyme inhibitor medication may exceed the risk of more severe anaphylaxis if the medication is continued, especially in patients with insect sting anaphylaxis. Evaluation for mastocytosis, including a bone marrow biopsy, should be considered for adult patients with severe insect sting anaphylaxis or recurrent idiopathic anaphylaxis. After perioperative anaphylaxis, repeat anesthesia may proceed in the context of shared decision-making and based on the history and results of diagnostic evaluation with skin tests or in vitro tests when available, and supervised challenge when necessary.

Immunological Mechanisms in Cutaneous Adverse Drug Reactions

Adverse drug reactions (ADRs) are an inherent aspect of drug use. While approximately 80% of ADRs are predictable, immune system-mediated ADRs, often unpredictable, are a noteworthy subset. Skin-related ADRs, in particular, are frequently unpredictable. However, the wide spectrum of skin manifestations poses a formidable diagnostic challenge. Comprehending the pathomechanisms underlying ADRs is essential for accurate diagnosis and effective management. The skin, being an active immune organ, plays a pivotal role in ADRs, although the precise cutaneous immunological mechanisms remain elusive. Fortunately, clinical manifestations of skin-related ADRs, irrespective of their severity, are frequently rooted in immunological processes. A comprehensive grasp of ADR morphology can aid in diagnosis. With the continuous development of new pharmaceuticals, it is noteworthy that certain drugs including immune checkpoint inhibitors have gained notoriety for their association with ADRs. This paper offers an overview of immunological mechanisms involved in cutaneous ADRs with a focus on clinical features and frequently implicated drugs.

Suspected Rivaroxaban-Induced Anaphylaxis Secondary to Ingestion of Rivaroxaban and Nimesulide Without Cross-Reactivity to Dabigatran - A Case Report

Here, we describe a case of anaphylaxis secondary to rivaroxaban in a 61-year-old woman 24 hours after orthopedic surgery. 10-15 minutes after ingestion of rivaroxaban and nimesulide, the patient's palms started itching, her face and lips swelled, her face flushed, she developed shortness of breath and subsequently lost consciousness. Serum tryptase levels at the time of the anaphylactic reaction were elevated, with subsequent measurement one month later returning a value within the normal range. Dabigatran and meloxicam were identified as suitable alternative drugs by oral provocation at an allergy clinic. Even though rivaroxaban rarely causes serious allergic reactions, when prescribing it, it is important to analyze patients' medical history for possible previously experienced drug-induced allergic reactions and to be aware of the risks of possible undesired drug interactions.

Safety and outcomes of "at-home self-provocation tests" in patients with mild nonsteroidal anti-inflammatory drug-induced urticaria/angioedema

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity is common; however, many patients do not receive an accurate diagnosis and are using unnecessary alternative drugs or have medication restrictions.

OBJECTIVE

To establish a protocol for provocation tests that can be performed safely and effectively at home to give patients an accurate diagnosis, whereas also delabeling NSAID hypersensitivity.

METHODS

We retrospectively analyzed the medical records of 147 patients with NSAID hypersensitivity. All patients had NSAID-induced urticaria/angioedema with less than 10% body surface area skin involvement. One specialist developed the protocol through history taking and chart review. If NSAID hypersensitivity was confirmed, an oral provocation test was performed to confirm the safe alternative medications (group A). If it was undetermined, an oral provocation test was performed to confirm the diagnosis and alternative medications (group B). All oral provocation tests were performed by patients in their homes according to the protocol.

RESULTS

Approximately 26% of group A patients had urticaria or angioedema symptoms with alternative drugs, whereas the remaining 74% was safe. In group B, 34% of the patients were diagnosed with having NSAID hypersensitivity. However, 61% did not respond to the culprit drug; therefore, NSAID hypersensitivity had been misdiagnosed. During this at-home self-provocation test, no severe hypersensitivity reactions occurred.

CONCLUSION

Many patients originally suspected of having NSAID hypersensitivity were confirmed to have been misdiagnosed. We successfully conducted an effective and safe at-home self-provocation test.

Tools for Etiologic Diagnosis of Drug-Induced Allergic Conditions

Drug hypersensitivity reactions are a serious concern in clinical practice because they can be severe and result in lifelong sequelae. An accurate diagnosis and identification of the culprit drug is essential to prevent future reactions as well as for the identification of safe treatment alternatives. Nonetheless, the diagnosis can be challenging. In vivo and in vitro tests can be helpful, although none are conclusive; therefore, the tests are not usually performed in isolation but as part of a diagnostic algorithm. In addition, some in vitro tests are only available in research laboratories, and standardization has not been fully accomplished. Collaborating research is needed to improve drug hypersensitivity reaction diagnosis. In this review, we update the current available in vivo and in vitro tools with their pros and cons and propose an algorithm to integrate them into clinical practice.

Effects of sodium metabisulfite on pyroptosis, mitophagy and degranulation in mast cells

Sodium metabisulphite (SMB) is the most used foods and drugs antioxidant among sulfites. So far, there were few studies about its harm, especially in mast cells. Our study was to investigate the effects of SMB on mitophagy and pyroptosis in mast cells. The results revealed that SMB dose-dependently promoted the expressions of NLRP3, GSDMD-N and other marker proteins of pyroptosis. Knockdown of GSDMD, NLRP3 inhibitor, mitophagy activator and mtROS inhibitor all reversed the changes in pyroptosis indicators caused by SMB. Considering the degranulation characteristics of mast cells and the sensitization of sulfite, we examined the effects of the above inhibitors on the degranulation of mast cells caused by SMB. The results showed that SMB-mediated mast cell degranulation was significantly inhibited by the above inhibitors. Meanwhile, we used immunofluorescence co-localization experiments and found that GSDMD pore-forming protein and histamine co-localized near the cell membrane. Overall, evidence suggested that SMB caused pyroptosis by inhibiting mitophagy, leading to mast cell degranulation. These findings are of great significance to the sensitization mechanism of SMB and provide a new insight into SMB toxicology and mast cell degranulation.

Microneedle array patches for allergen-specific immunotherapy

The incidence of allergies has been steadily increasing in recent years. Allergen-specific immunotherapy (AIT) represents the only approach capable of inducing long-term immune tolerance toward allergens. However, the clinical success of AIT is limited by efficacy or safety concerns related to the administration route. Therapeutic delivery in the skin appears promising, given the presence of immune cells in the skin and the relatively low level of systemic distribution that occurs with this delivery method. However, the stratum corneum greatly limits this route. In this regard, the use of microneedles has been proposed to improve the delivery of therapeutics into the skin. In this review, we discuss recent developments in the use of microneedles for AIT, highlighting avenues for future research.

Severe Hypersensitivity Reactions at Biosimilar versus Originator Rituximab Treatment Initiation, Switch and Over Time: A Cohort Study on the French National Health Data System

BACKGROUND

Biosimilar products of rituximab came to market in 2017. French pharmacovigilance centers have highlighted an excess of case reports of severe hypersensitivity reactions related to their use compared with the originator product.

OBJECTIVE

The aim of this study was to assess the real-world association between biosimilar versus originator rituximab injections and hypersensitivity reactions, among initiators and switchers, at first injection and over time.

METHODS

The French National Health Data System was used to identify all rituximab users between 2017 and 2021. A first cohort consisted of patients who initiated rituximab (originator or biosimilar), while a second cohort consisted of originator-to-biosimilar switchers, matched on age, sex, deliveries history, and pathology, with one or two patients still receiving the originator product. The event of interest was defined as a hospitalization for anaphylactic shock or serum sickness following a rituximab injection.

RESULTS

A total of 91,894 patients were included in the initiation cohort-17,605 (19%) with the originator product and 74,289 (81%) with a biosimilar. At initiation, 86/17,605 (0.49%) and 339/74,289 (0.46%) events occurred in the originator and biosimilar groups, respectively. The adjusted odds ratio of biosimilar exposure associated with the event was 1.04 (95% confidence interval [CI] 0.80-1.34), and the adjusted hazard ratio for biosimilar versus originator exposure was 1.15 (95% CI 0.93-1.42), showing no increased risk of event with biosimilar use at first injection, and over time. 17,123 switchers were matched to 24,659 non-switchers. No association was found between switch to biosimilars and occurrence of the event.

CONCLUSION

Our study does not support any association between exposure to rituximab biosimilars versus originator and hospitalization for a hypersensitivity reaction, either at initiation, at switch, or over time.

DOCK2 regulates MRGPRX2/B2-mediated mast cell degranulation and drug-induced anaphylaxis

BACKGROUND

Drug-induced anaphylaxis is triggered by the direct stimulation of mast cells (MCs) via Mas-related G protein-coupled receptor X2 (MRGPRX2; mouse ortholog MRGPRB2). However, the precise mechanism that links MRGPRX2/B2 to MC degranulation is poorly understood. Dedicator of cytokinesis 2 (DOCK2) is a Rac activator predominantly expressed in hematopoietic cells. Although DOCK2 regulates migration and activation of leukocytes, its role in MCs remains unknown.

OBJECTIVE

We aimed to elucidate whether-and if so, how-DOCK2 is involved in MRGPRX2/B2-mediated MC degranulation and anaphylaxis.

METHODS

Induction of drug-induced systemic and cutaneous anaphylaxis was compared between wild-type and DOCK2-deficient mice. In addition, genetic or pharmacologic inactivation of DOCK2 in human and murine MCs was used to reveal its role in MRGPRX2/B2-mediated signal transduction and degranulation.

RESULTS

Induction of MC degranulation and anaphylaxis by compound 48/80 and ciprofloxacin was severely attenuated in the absence of DOCK2. Although calcium influx and phosphorylation of several signaling molecules were unaffected, MRGPRB2-mediated Rac activation and phosphorylation of p21-activated kinase 1 (PAK1) were impaired in DOCK2-deficient MCs. Similar results were obtained when mice or MCs were treated with small-molecule inhibitors that bind to the catalytic domain of DOCK2 and inhibit Rac activation.

CONCLUSION

DOCK2 regulates MRGPRX2/B2-mediated MC degranulation through Rac activation and PAK1 phosphorylation, thereby indicating that the DOCK2-Rac-PAK1 axis could be a target for preventing drug-induced anaphylaxis.

Delayed Anaphylaxis to Intravenous Colistin in a Critically Ill Cancer Patient: A Case Report

Introduction

Anaphylaxis is an acute, life-threatening, multi-system syndrome that has been reported with a wide range of medications. Though anaphylaxis usually has a rapid onset, we describe a patient who developed anaphylaxis to intravenous colistin after 28 days of daily administration.

Case presentation

A 20 years-old Caucasian male patient, with a history of relapsed acute myeloid leukemia, was transferred from the medical floor to our intensive care unit with septic shock. The source of infection was presumed to be a recto-cecal abscess and arm cellulitis. Cultures were positive for extended spectrum beta-lactamase (ESBL) and carbapenem-resistant enterobacteriaceae (CRE) Escherichia coli. for which he was receiving broad spectrum antibiotics, as well as intravenous colistin, started about 4 weeks earlier. On day 2 of ICU admission, and during the administration of colistin, the patient experienced an anaphylactic reaction. He developed hypotension requiring the initiation of norepinephrine, shortness of breath, hypoxia, tachycardia, and tachypnea. The reaction was resolved after supportive therapy but it was thought to be related to septic shock and therefore the patient continued on colistin the following day. The patient tolerated colistin for the next 3 days before developing another similar, but more severe, reaction. Colistin was discontinued and the symptoms resolved following supportive therapy.

Conclusion

This case highlights the importance of being aware of delayed serious reactions that may occur several weeks after initiation of drug therapy. In addition, successful re-initiation may not necessarily rule out the recurrence of such reactions and therefore close monitoring is crucial.

Development and Validation for Quantification of Cephapirin and Ceftiofur by Ultraperformance Liquid Chromatography with Triple Quadrupole Mass Spectrometry

Cross contamination of β-lactams is one of the highest risks for patients using pharmaceutical products. Penicillin and some non-penicillin β-lactams may cause potentially life-threatening allergic reactions. The trace detection of β-lactam antibiotics in cleaning rinse solutions of common reactors and manufacturing aids in pharmaceutical facilities is very crucial. Therefore, the common facilities adopt sophisticated cleaning procedures and develop analytical methods to assess traces of these compounds in rinsed solutions. For this, a highly sensitive and reproducible ultra-performance liquid chromatography with triple quadrupole mass spectrometry (UHPLC-MS/MS) method was developed for the analysis of Cephapirin and Ceftiofur. As per the FDA guidelines described in FDA-2011-D-0104, the contamination of these β-lactam antibiotics must be regulated. The analysis was performed on an XBridge C18 column with 100 mm length, 4.6 mm diameter, and 3.5 µm particle size at an oven temperature of about 40 °C. The mobile phase was composed of 0.15% formic acid in water and acetonitrile as mobile phases A and B, and a flow rate was set to 0.6 mL/min. The method was validated for Cephapirin and Ceftiofur. The quantification precision and accuracy were determined to be the lowest limit of detection 0.15 parts per billion (ppb) and the lowest limit of quantification 0.4 ppb. This method was linear in the range of 0.4 to 1.5 ppb with the determination of coefficient (R2 > 0.99). This sensitive and fast method was fit-for-purpose for detecting and quantifying trace amounts of β-lactam contamination, monitoring cross contamination in facility surface cleaning, and determining the acceptable level of limits for regulatory purposes.

The Crosstalk between FcεRI and Sphingosine Signaling in Allergic Inflammation

Sphingolipid molecules have recently attracted attention as signaling molecules in allergic inflammation diseases. Sphingosine-1-phosphate (S1P) is synthesized by two isoforms of sphingosine kinases (SPHK 1 and SPHK2) and is known to be involved in various cellular processes. S1P levels reportedly increase in allergic inflammatory diseases, such as asthma and anaphylaxis. FcεRI signaling is necessary for allergic inflammation as it can activate the SPHKs and increase the S1P level; once S1P is secreted, it can bind to the S1P receptors (S1PRs). The role of S1P signaling in various allergic diseases is discussed. Increased levels of S1P are positively associated with asthma and anaphylaxis. S1P can either induce or suppress allergic skin diseases in a context-dependent manner. The crosstalk between FcεRI and S1P/SPHK/S1PRs is discussed. The roles of the microRNAs that regulate the expression of the components of S1P signaling in allergic inflammatory diseases are also discussed. Various reports suggest the role of S1P in FcεRI-mediated mast cell (MC) activation. Thus, S1P/SPHK/S1PRs signaling can be the target for developing anti-allergy drugs.

Anaphylaxis in Children and Adolescents: Greek Data Analysis from the European Anaphylaxis Registry (NORA)

The European Anaphylaxis Registry (NORA) was designed in order to create a comprehensive Anaphylaxis Registry regarding anaphylactic reactions characteristics and management in several European countries, including Greece. This study aims to analyze Greek data obtained in the NORA framework and describe anaphylaxis’ characteristics in this pediatric cohort. An online questionnaire was filled out by the Allergy Unit of the 2nd Pediatric Department of NKUA, regarding reported anaphylaxis characteristics. A total of 284 pediatric patients were analyzed. Patients were predominantly male. A previous, mild reaction (59.5%) to the same allergen was documented in 44.4% of patients. The most common system involved was skin and/or mucosa, followed by the respiratory system. Food was the most common eliciting factor (82.4%). First line treatment was most administered solely by a healthcare professional, followed by a lay person (38.7%). Auto injected adrenaline use by lay persons was third in frequency (29.2%). Most patients received post-reaction counseling and appropriate drug prescription. This study provides insight in anaphylactic cases’ characteristics and management in a Greek pediatric cohort. A low rate of adrenaline autoinjector administration was noted in lay people; however, drug prescription and counseling following the reaction could help increase correct acute anaphylaxis management in the future.

Case Report: A successful case of toxic epidermal necrolysis treated with plasmapheresis therapy

Toxic epidermal necrosis (TEN) is rare and can be life-threatening for patients. Appropriate management of TEN patients could give optimal results and prevent complications. One treatment modality for TEN is plasmapheresis, which is rarely available in most cases with severe TEN. Here we reported a successful treatment of severe TEN with plasmapheresis. A 40-year-old woman under tuberculosis therapy complained of shortness of breath that began four days prior to hospital admission and worsened ever since. The patient's skin was peeling with red spots and rashes all over the body for a week. During the examination, the patient was compos mentis, and the SCORTEN score was 2 with 12.1% risk of mortality rate. Dermatological examination of the face, trunk and extremities found extensive erosions, loose bullae filled with clear fluid, brown crusts, and generalized distribution with more than 30% epidermolysis. The patient was diagnosed with toxic epidermal necrolysis caused by antituberculosis therapy. We treated the patient by discontinuing the suspected drugs and administering the corticosteroids, but no improvement was observed. The patient underwent two cycle plasmaphereses with 5% albumin, resulting in 1.2 liter of plasma exchange. Re-epithelialization was observed after three days, and the patient was discharged on day 8. This case-report highlights the important role of plasmapheresis in treating the TEN patients. However, a study with larger sample sizes is warranted to validate the efficacy of plasmapheresis in TEN.

Glucagon-Like Peptide 1 Receptor Agonists and Risk of Anaphylactic Reaction Among Patients With Type 2 Diabetes: A Multisite Population-Based Cohort Study

Case reports and a pharmacovigilance analysis have linked glucagon-like peptide 1 receptor agonists (GLP-1 RAs) with anaphylactic reactions, but real-world evidence for this possible association is lacking. Using databases from the United Kingdom (Clinical Practice Research Datalink) and the United States (Medicare, Optum (Optum, Inc., Eden Prairie, Minnesota), and IBM MarketScan (IBM, Armonk, New York)), we employed a new-user, active comparator study design wherein initiators of GLP-1 RAs were compared with 2 different active comparator groups (initiators of dipeptidyl peptidase 4 (DPP-4) inhibitors and initiators of sodium-glucose cotransporter 2 (SGLT-2) inhibitors) between 2007 and 2019. Propensity score fine stratification weighted Cox proportional hazards models were fitted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for an anaphylactic reaction. Database-specific HRs were pooled using random-effects models. Compared with the use of DPP-4 inhibitors (n = 1,641,520), use of GLP-1 RAs (n = 324,098) generated a modest increase in the HR for anaphylactic reaction, with a wide 95% CI (36.9 per 100,000 person-years vs. 32.1 per 100,000 person-years, respectively; HR = 1.15, 95% CI: 0.94, 1.42). Compared with SGLT-2 inhibitors (n = 366,067), GLP-1 RAs (n = 259,929) were associated with a 38% increased risk of anaphylactic reaction (40.7 per 100,000 person-years vs. 29.4 per 100,000 person-years, respectively; HR = 1.38, 95% CI: 1.02, 1.87). In this large, multisite population-based cohort study, GLP-1 RAs were associated with a modestly increased risk of anaphylactic reaction when compared with DPP-4 inhibitors and SGLT-2 inhibitors.

Mast Cell Desensitization in Allergen Immunotherapy

Allergen immunotherapy (AIT) is the only treatment with disease-transforming potential for allergic disorders. The immunological mechanisms associated with AIT can be divided along time in two phases: short-term, involving mast cell (MC) desensitization; and long-term, with a regulatory T cell (Treg) response with significant reduction of eosinophilia. This regulatory response is induced in about 70% of patients and lasts up to 3 years after AIT cessation. MC desensitization is characteristic of the initial phase of AIT and it is often related to its success. Yet, the molecular mechanisms involved in allergen-specific MC desensitization, or the connection between MC desensitization and the development of a Treg arm, are poorly understood. The major AIT challenges are its long duration, the development of allergic reactions during AIT, and the lack of efficacy in a considerable proportion of patients. Therefore, reaching a better understanding of the immunology of AIT will help to tackle these short-comings and, particularly, to predict responder-patients. In this regard, omics strategies are empowering the identification of predictive and follow-up biomarkers in AIT. Here, we review the immunological mechanisms underlying AIT with a focus on MC desensitization and AIT-induced adverse reactions. Also, we discuss the identification of novel biomarkers with predictive potential that could improve the rational use of AIT.

Advances in Our Understanding of the Interaction of Drugs with T-cells: Implications for the Discovery of Biomarkers in Severe Cutaneous Drug Reactions

Drugs can activate different cells of the immune system and initiate an immune response that can lead to life-threatening diseases collectively known as severe cutaneous adverse reactions (SCARs). Antibiotics, anticonvulsants, and antiretrovirals are involved in the development of SCARs by the activation of αβ naïve T-cells. However, other subsets of lymphocytes known as nonconventional T-cells with a limited T-cell receptor repertoire and innate and adaptative functions also recognize drugs and drug-like molecules, but their role in the pathogenesis of SCARs has only just begun to be explored. Despite 30 years of advances in our understanding of the mechanisms in which drugs interact with T-cells and the pathways for tissue injury seen during T-cell activation, at present, the development of useful clinical biomarkers for SCARs or predictive preclinical in vitro assays that could identify immunogenic moieties during drug discovery is an unmet goal. Therefore, the present review focuses on (i) advances in the understanding of the pathogenesis of SCARs reactions, (ii) a description of the interaction of drugs with conventional and nonconventional T-cells, and (iii) the current state of soluble blood circulating biomarker candidates for SCARs.

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.

The Role of Sphingolipids in Allergic Disorders

Allergy is defined as a complex chronic inflammatory condition in which genetic and environmental factors are implicated. Sphingolipids are involved in multiple biological functions, from cell membrane components to critical signaling molecules. To date, sphingolipids have been studied in different human pathologies such as neurological disorders, cancer, autoimmunity, and infections. Sphingolipid metabolites, in particular, ceramide and sphingosine-1-phosphate (S1P), regulate a diverse range of cellular processes that are important in immunity and inflammation. Moreover, variations in the sphingolipid concentrations have been strongly associated with allergic diseases. This review will focus on the role of sphingolipids in the development of allergic sensitization and allergic inflammation through the activation of immune cells resident in tissues, as well as their role in barrier remodeling and anaphylaxis. The knowledge gained in this emerging field will help to develop new therapeutic options for allergic disorders.

Drug-induced anaphylaxis in the emergency department: A prospective observational study

Objective

Anaphylaxis is an acute, life-threatening, systemic hypersensitivity reaction. It is usually triggered by drugs, foods, and insect stings. The primary objective of our study is to determine the factors affecting drug-induced anaphylaxis to contribute to early diagnosis and treatment in these patients.

Methods

Patients over 18 years old who were diagnosed drug-induced anaphylaxis in the Goztepe Hospital within a period of 1 year were evaluated prospectively. Patients demographical data, etiological factors, clinical findings, and treatment information were recorded.

Results

Forty-four patients were enrolled in the study of which 25 (56.8%) were female. The median age of women and men was 54 (min: 22, max 82) and 44 (min 18, max 82), respectively. Twenty-three (52%) of them had a history of anaphylaxis. The most common causes of drug-induced anaphylaxis were antibiotics (36%) and nonsteroidal anti-inflammatory drugs (18%), respectively. Adrenaline was applied to 17 (38%) of the patients in the treatment.

Conclusion

Antibiotics were the most common drugs causing drug-induced anaphylaxis and adrenaline was underused which is the first-line treatment in the anaphylaxis. Some clinicians refrain from administering adrenaline. The reasons underlying this approach should be investigated.

Risk predictive tools of perioperative drug hypersensitivity reaction: A case-control study

Objective

We aimed to determine the risk factors of perioperative drug hypersensitivity reaction (DHR) and develop a predictive score for use in clinical practice.

Methods

A case-control study was conducted in patients who underwent anesthesia at a tertiary hospital in Thailand, between 2015–2018. DHR cases were graded clinically from 1 to 4 according to the World Federation of Societies of Anesthesiologists by two anesthesiologists. Controls were randomly matched with cases (ratio 2:1) by age group and month and type of surgery. Patient and anesthesia-related factors and agents given intraoperatively were recorded. A risk score was derived from the coefficients of the significant predictors of the final multivariate logistic regression model. Risk scores, adjusted odds ratios (OR) for perioperative DHR and 95% confidence intervals (CI) were determined.

Results

Overall, 325 cases and 650 controls were recruited. The severity of DHR was grade 1 (72.9%), grade 2 (24%), and grade 3 (3.1%). Our risk predictive tools for perioperative DHR provided a sensitivity of 62% and specificity of 65%. Predictive scores of subgroups of moderate to severe DHR showed high specificity (80%) but low sensitivity (47%). Common predictors of overall DHR and moderate to severe DHR were history of drug allergy to 2 or more drug categories (score 2.5–3.5), being allergic to analgesics (score 2.5–4.0), and intraoperative morphine use (score of 1). The sole predictor of high-risk perioperative DHR (score ≥3.5) was airway management with an endotracheal tube intubation (OR 5.6, 95% CI 2.2–14.4) whereas history of allergic rhinitis (OR 11.7, 95% CI 1.3–105.1) was a predictor of high-risk moderate to severe DHR (score ≥2.5).

Conclusions

Our predictive tool for perioperative DHR provided a modest predictive ability. History of drug allergies, rhinitis, morphine use and endotracheal intubation were significant risk factors of DHR after adjusting for age and type of surgery.

The FcεRI signaling pathway is involved in the pathogenesis of lacrimal gland benign lymphoepithelial lesions as shown by transcriptomic analysis

This study aimed to analyze the role of the FcepsilonRI (FcεRI) signaling pathway in the pathogenesis of benign lymphoepithelial lesion of lacrimal gland (LGBLEL). Transcriptomic analysis was performed on LGBLEL and orbital cavernous hemangioma (CH) patients diagnosed via histopathology in Beijing Tongren Hospital, Capital Medical University, between July 2010 and October 2013. Four LGBLEL and three orbital CH patients, diagnosed between October 2018 and August 2019, were randomly selected as experimental and control groups, respectively. RT-PCR, immunohistochemical staining, and western blotting were used to verify genes and proteins related to the FcεRI signaling pathway. Transcriptomic analysis showed that the FcεRI signaling pathway was upregulated in the LGBLEL compared with the CH group. The mRNA expression levels of important genes including SYK, p38, JNK, PI3K, and ERK were significantly increased in the LGBLEL group (P = 0.0066, P = 0.0002, P = 0.0003, P < 0.0001, P < 0.0001, respectively). Immunohistochemical staining results showed that SYK, p38, and ERK were positively expressed in LGBLEL, while JNK and PI3K were not. The protein contents of P-SYK, P-p38, P-JNK, P-PI3K, and P-ERK were significantly higher in the LGBLEL than in the CH group (P = 0.0169, P = 0.0074, P = 0.0046, P = 0.0157, P = 0.0156, respectively). The FcεRI signaling pathway participates in the pathogenesis of LGBLEL.

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.

State-of-the-Art on Biomarkers for Anaphylaxis in Obstetrics

Anaphylaxis is an unpredictable systemic hypersensitivity reaction and constitutes a high risk of maternal and fetal morbidity and mortality when occurring during pregnancy. Currently, the acute management of anaphylaxis is based on clinical parameters. A total serum tryptase is only used to support an accurate diagnosis. There is a need to detect other biomarkers to further assess high-risk patients in obstetrics. Our objective is to present biomarkers in this complex interdisciplinary approach beyond obstetrician and anaesthetic management. Candidate biomarkers derive either from mediators involved in immunopathogenesis or upcoming molecules from systems biology and proteomics. Serum tryptase is determined by singleplex immunoassay method and is important in the evaluation of anaphylactic mast cell degranulation but also in the assessment of other risk factors for anaphylaxis such as systemic mastocytosis. Another category of biomarkers investigates the IgE-mediated sensitization to triggers potentially involved in the etiology of anaphylaxis in pregnant women, using singleplex or multiplex immunoassays. These in vitro tests with natural extracts from foods, venoms, latex or drugs, as well as with molecular allergen components, are useful because in vivo allergy tests cannot be performed on pregnant women in such a major medical emergency due to their additional potential risk of anaphylaxis.

Validity of hospital ICD-10-GM codes to identify anaphylaxis

PURPOSE

Anaphylaxis (ANA) is an important adverse drug reaction. We examined positive predictive values (PPV) and other test characteristics of ICD-10-GM code algorithms for detecting ANA as used in a multinational safety study (PASS).

METHODS

We performed a cross-sectional study on routine data from a German academic hospital (2004-2019, age ≥ 18). Chart review was used for case verification. Potential cases were identified from the hospital administration system. The main outcome required at least one of the following: any type of specific in-hospital code (T78.2, T88.6, and T80.5) OR specific outpatient code in combination with a symptom code OR in-hospital non-specific code (T78.4, T88.7, and Y57.9) in combination with two symptom codes. PPV were calculated with 95% confidence interval. Sensitivity analyses modified type of codes, unit of analysis, verification criteria and time period. The most specific algorithm used only primary codes for ANA (numbers added in brackets).

RESULTS

Four hundred and sixteen eligible cases were evaluated, and 78 (37) potential ANA cases were identified. PPV were 62.8% (95% CI 51.1-73.5) (main) and 77.4% (58.9-90.4) (most specific). PPV from all modifications ranged from 12.9% to 80.6%. The sensitivity of the main algorithm was 66.2%, specificity 91.5%, and negative predictive value 92.6%. Corresponding figures for the most specific algorithm were 32.4%, 98.0%, and 87.0%.

CONCLUSIONS

The PPV of the main algorithm seems of acceptable validity for use in comparative safety research but will underestimate absolute risks by about a third. Restriction to primary discharge codes markedly improves PPV to the expense of reducing sensitivity.

Machine Learning Approach for Active Vaccine Safety Monitoring

BACKGROUND

Vaccine safety surveillance is important because it is related to vaccine hesitancy, which affects vaccination rate. To increase confidence in vaccination, the active monitoring of vaccine adverse events is important. For effective active surveillance, we developed and verified a machine learning-based active surveillance system using national claim data.

METHODS

We used two databases, one from the Korea Disease Control and Prevention Agency, which contains flu vaccination records for the elderly, and another from the National Health Insurance Service, which contains the claim data of vaccinated people. We developed a case-crossover design based machine learning model to predict the health outcome of interest events (anaphylaxis and agranulocytosis) using a random forest. Feature importance values were evaluated to determine candidate associations with each outcome. We investigated the relationship of the features to each event via a literature review, comparison with the Side Effect Resource, and using the Local Interpretable Model-agnostic Explanation method.

RESULTS

The trained model predicted each health outcome of interest with a high accuracy (approximately 70%). We found literature supporting our results, and most of the important drug-related features were listed in the Side Effect Resource database as inducing the health outcome of interest. For anaphylaxis, flu vaccination ranked high in our feature importance analysis and had a positive association in Local Interpretable Model-Agnostic Explanation analysis. Although the feature importance of vaccination was lower for agranulocytosis, it also had a positive relationship in the Local Interpretable Model-Agnostic Explanation analysis.

CONCLUSION

We developed a machine learning-based active surveillance system for detecting possible factors that can induce adverse events using health claim and vaccination databases. The results of the study demonstrated a potentially useful application of two linked national health record databases. Our model can contribute to the establishment of a system for conducting active surveillance on vaccination.

Proteomic and Biological Analysis of an In Vitro Human Endothelial System in Response to Drug Anaphylaxis

Anaphylaxis is a life-threatening systemic hypersensitivity reaction. During anaphylaxis, mediator release by effector cells causes endothelial barrier breakdown, increasing vascular permeability and leakage of fluids, which may lead to tissue edema. Although endothelial cells (ECs) are key players in this context, scant attention has been paid to the molecular analysis of the vascular system, and further analyses of this cell type are necessary, especially in humans. The protein expression pattern of human microvascular ECs was analyzed in response to sera from anaphylactic patients (EC-anaphylaxis) and sera from non-allergic subjects (EC-control) after 2 hours of contact. Firstly, a differential quantitative proteomic analysis of the protein extracts was performed by mass spectrometry using an isobaric labeling method. Second, the coordinated behavior of the identified proteins was analyzed using systems biology analysis (SBA). The proteome of the EC-anaphylaxis system showed 7,707 proteins, of which 1,069 were found to be significantly altered between the EC-control and EC-anaphylaxis groups (p-value < 0.05). Among them, a subproteome of 47 proteins presented a high rate of change (|ΔZq| ≥ 3). This panel offers an endothelial snapshot of the anaphylactic reaction. Those proteins with the highest individual changes in abundance were hemoglobin subunits and structural support proteins. The interacting network analysis of this altered subproteome revealed that the coagulation and complement systems are the main biological processes altered in the EC-anaphylactic system. The comprehensive SBA resulted in 5,512 functional subcategories (biological processes), 57 of which were significantly altered between EC-control and EC-anaphylaxis. The complement system, once again, was observed as the main process altered in the EC system created with serum from anaphylactic patients. Findings of the current study further our understanding of the underlying pathophysiological mechanisms operating in anaphylactic reactions. New target proteins and relevant signaling pathways operating in the in vitro endothelial-serum system have been identified. Interestingly, our results offer a protein overview of the micro-EC-anaphylaxis environment. The relevance of the coagulation, fibrinolytic, contact and complement systems in human anaphylaxis is described. Additionally, the untargeted high-throughput analysis used here is a novel approach that reveals new pathways in the study of the endothelial niche in anaphylaxis.

Sodium R-lipoate and enzymatically-modified isoquercitrin suppressed IgE-independent anaphylactic reactions and stress-induced gastric ulceration in mice

Anaphylaxis is a life-threatening allergic reaction, for which the worldwide prevalence is rapidly increasing. The currently used synthetic antiallergic drugs have a high tendency to cause adverse effects, like gastric ulcers, in long-term use. Therefore, a great deal of attention has been given to develop new safer and more effective antiallergic agents from natural compounds that are chemically/enzymatically-modified. Here, we evaluated/compared the efficacy of two different doses (50 and 100 mg/kg body weight "b.w", given orally) of sodium R-lipoate (NaRLA) and enzymatically-modified isoquercitrin (EMIQ) in alleviating both local/systemic non-immunological anaphylactic reactions and stress-induced gastric ulceration in mice, in comparison with sulfasalazine (SSZ) as a reference drug. The results indicated that the pre-treatment of animals with NaRLA or EMIQ (especially at 100 mg/kg b.w) completely succeeded, as SSZ, in alleviating the hind paw edema induced by either histamine or compound 48/80 (Cpd 48/80). Furthermore, NaRLA and EMIQ prevented the mast cell degranulation and anaphylactic shock caused by Cpd 48/80 (in a dose-dependent manner) and reduced significantly (P < 0.001) the histamine release from the mouse peritoneal mast cells, like SSZ. Moreover, their use was associated with alleviating both gastric histopathological and biochemical alterations in the water-restraint stress (WRS) mice model towards the control values. They also decreased the percentage of degranulated mesenteric mast cells in the WRS mice model. In conclusion, our findings provide possibility that both NaRLA and EMIQ may serve as an effective therapeutic agents for mast cells-dependent anaphylactic reactions without risks of inducing gastric ulcers.

Anaphylaxis following rivaroxaban ingestion: report of an extremely rare case

We reported an anaphylactic reaction following ingestion of rivaroxaban in a 48-years-old male, who was recently discharged from the hospital as a case of deep vein thrombosis. At home, the patient developed a diffuse itchy skin rash, shortness of breath, and vomiting 30 minutes after rivaroxaban ingestion. Emergency Medical Service found that the patient had severe dyspnea, low blood pressure, and decreased blood oxygen saturation. The patient was given oxygen, intramuscular epinephrine, intravenous hydrocortisone, diphenhydramine, salbutamol nebulizer, and was immediately transferred to the emergency department of Hamad General Hospital. Subcutaneous enoxaparin was initiated, while hydrocortisone and salbutamol nebulizer continued. On the next day, his vital signs had stabilized, and intravenous hydrocortisone was switched to prednisolone tablets, and salbutamol nebulizer was switched to budesonide/salmeterol inhaler, whereas enoxaparin was overlapped with warfarin. After achieving the target international normalized ratio (INR), enoxaparin was discontinued and the patient was discharged with significant clinical and laboratory improvement.

Hypersensitivity reactions and anaphylaxis to checkpoint inhibitor-monoclonal antibodies and desensitization

OBJECTIVE

To review type 1 hypersensitivity reactions and anaphylaxis to checkpoint inhibitor-monoclonal antibodies and its management with drug desensitization.

DATA SOURCES

English-language literature on MEDLINE regarding hypersensitivity, anaphylaxis, and checkpoint inhibitor-monoclonal antibodies.

STUDY SELECTIONS

References were selected based on relevance, novelty, robustness, and applicability.

RESULTS

There are well-known tissue toxicities associated to checkpoint inhibitors, but hypersensitivity reactions and anaphylaxis have been underreported. The presentation of these reactions is based on clinical phenotypes with underlying endotypes identified by specific biomarkers. Drug desensitizations have been successfully applied to checkpoint inhibitor drugs to allow patients with cancer to receive first-line therapies. This review provides current best practices for the recognition and diagnosis of hypersensitivity reactions and anaphylaxis to checkpoint inhibitors and their management using drug desensitization.

CONCLUSION

Hypersensitivity reactions and anaphylaxis have been identified as potential adverse effects induced by checkpoint inhibitor-monoclonal antibodies. Drug desensitization is a safe and effective treatment option for patients who experience hypersensitivity reactions in need of these monoclonal antibodies to improve cancer outcomes.

Beyond somatosensation: Mrgprs in mucosal tissues

Mas-related G coupled receptors (Mrgprs) are a superfamily of receptors expressed in sensory neurons that are known to transmit somatic sensations from the skin to the central nervous system. Interestingly, Mrgprs have recently been implicated in sensory and motor functions of mucosal-associated neuronal circuits. The gastrointestinal and pulmonary tracts are constantly exposed to noxious stimuli. Therefore, it is likely that neuronal Mrgpr signaling pathways in mucosal tissues, akin to their family members expressed in the skin, might relay messages that alert the host when mucosal tissues are affected by damaging signals. Further, Mrgprs have been proposed to mediate the cross-talk between sensory neurons and immune cells that promotes host-protective functions at barrier sites. Although the mechanisms by which Mrgprs are activated in mucosal tissues are not completely understood, these exciting studies implicate Mrgprs as potential therapeutic targets for conditions affecting the intestinal and airway mucosa. This review will highlight the central role of Mrgpr signaling pathways in the regulation of homeostasis at mucosal tissues.

Biotin-Labelled Clavulanic Acid to Identify Proteins Target for Haptenation in Serum: Implications in Allergy Studies

Clavulanic acid (CLV) and amoxicillin, frequently administered in combination, can be independently involved in allergic reactions. Protein haptenation with β-lactams is considered necessary to activate the immune system. The aim of this study was to assess the suitability of biotinylated analogues of CLV as probes to study protein haptenation by this β-lactam. Two synthetic approaches afforded the labeling of CLV through esterification of its carboxylic group with a biotin moiety, via either direct binding (CLV-B) or tetraethylenglycol linker (CLV-TEG-B). The second analogue offered advantages as solubility in aqueous solution and potential lower steric hindrance for both intended interactions, with the protein and with avidin. NMR reactivity studies showed that both CLV and CLV-TEG-B reacts through β-lactam ring opening by aliphatic amino nitrogen, however with different stability of resulting conjugates. Unlike CLV conjugates, that promoted the decomposition of clavulanate fragment, the conjugates obtained with the CLV-TEG-B remained linked, as a whole structure including biotin, to nucleophile and showed a better stability. This was a desired key feature to allow CLV-TEG-B conjugated protein detection at great sensitivity. We have used biotin detection and mass spectrometry (MS) to detect the haptenation of human serum albumin (HSA) and human serum proteins. MS of conjugates showed that HSA could be modified by CLV-TEG-B. Remarkably, HSA preincubation with CLV excess only reduced moderately the incorporation of CLV-TEG-B, which could be attributed to different protein interferences. The CLV-TEG-B fragment with opened β-lactam was detected bound to the ^404-430HSA peptide of the treated protein. Incubation of human serum with CLV-TEG-B resulted in the haptenation of several proteins that were identified by 2D-electrophoresis and peptide mass fingerprinting as HSA, haptoglobin, and heavy and light chains of immunoglobulins. Taken together, our results show that tagged-CLV keeps some of the CLV features. Moreover, although we observe a different behavior in the conjugate stability and in the site of protein modification, the similar reactivity indicates that it could constitute a valuable tool to identify protein targets for haptenation by CLV with high sensitivity to get insights into the activation of the immune system by CLV and mechanisms involved in β-lactams allergy.

Prostate Cancer Radiotherapy: Increased Biochemical Control and Late Toxicity in Men With Medication Allergies

Background

Given similarities in the mediators of medication allergy (MA) and tissue response to radiotherapy, we assessed whether outcomes following prostate radiotherapy differ in patients with MAs.

Methods

A total 587 men with known MA history and nonmetastatic prostate cancer underwent radiotherapy from 1989 to 2006. Clinicopathologic and treatment variables were analyzed for association with freedom from biochemical failure (FFBF) and late treatment–related, physician-defined Radiation Therapy Oncology Group gastrointestinal (GI) and genitourinary (GU) toxicity. Covariates identified on univariate analysis for toxicity and disease control were examined on multivariable analysis. All statistical tests were 2-sided, and a P less than .05 was considered statistically significant.

Results

A total of 155 of 587 men (26.4%) had 1 or more MAs, most commonly to penicillin (n = 71), sulfa (n = 35), and aspirin or nonsteroidal antiinflammatory drugs (n = 28). On univariate analysis, men with MAs had superior 10-y FFBF (71.5% vs 63.5%, P = .02) and higher incidence of late GI grade 2 or higher (G2+; 20.6% vs 13.2%, P = .04) and grade 3 or higher (G3+; 7.5% vs 3.9%, P = .08) as well as late GU G2+ (42.5% vs 33.2%, P = .04) and G3+ (7.5% vs 3.0%, P = .02) toxicity than men without MAs. On multivariable analysis, MA history remained a statistically significant predictor of FFBF (hazard ratio [HR] = 0.64, 95% confidence interval [CI] = 0.43 to 0.93, P = .02), late G2+ GI (HR = 1.76, 95% CI = 1.06 to 2.90, P=.03), and G3+ GU (HR = 2.69, 95% CI = 1.16 to 6.27, P = .02) toxicity after controlling for corresponding covariates in each model.

Conclusions

Men with MAs had improved FFBF and increased treatment-related toxicity following radiotherapy for prostate cancer. MA history could be a relevant consideration in the management of men with localized prostate cancer.

[Update on perioperative hypersensitivity reactions: joint document from the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part II: etiology and diagnosis]

This second joint document, written by experts from the Brazilian Association of Allergy and Immunology (ASBAI) and Brazilian Society of Anesthesiology (SBA) concerned with perioperative anaphylaxis, aims to review the pathophysiological reaction mechanisms, triggering agents (in adults and children), and the approach for diagnosis during and after an episode of anaphylaxis. As anaphylaxis assessment is extensive, the identification of medications, antiseptics and other substances used at each setting, the comprehensive data documentation, and the use of standardized nomenclature are key points for obtaining more consistent epidemiological information on perioperative anaphylaxis.

Update on perioperative hypersensitivity reactions: joint document from the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part II: etiology and diagnosis

This second joint document, written by experts from the Brazilian Association of Allergy and Immunology (ASBAI) and Brazilian Society of Anesthesiology (SBA) concerned with perioperative anaphylaxis, aims to review the pathophysiological reaction mechanisms, triggering agents (in adults and children), and the approach for diagnosis during and after an episode of anaphylaxis. As anaphylaxis assessment is extensive, the identification of medications, antiseptics and other substances used at each setting, the comprehensive data documentation, and the use of standardized nomenclature are key points for obtaining more consistent epidemiological information on perioperative anaphylaxis.

A Comprehensive Methodology to Systematically Identify Drug Hypersensitivity and Anaphylactic Reactions in Clinical Trial Databases

BACKGROUND

The incidence of drug hypersensitivity or anaphylactic reactions in clinical trial databases is thought to be underestimated due to variable clinical presentations and lack of clear definitions.

OBJECTIVE

Our objective was to develop a more comprehensive, systematic methodology for retrospectively identifying potential hypersensitivity or anaphylactic reactions reported in patients treated with investigational drugs in clinical trials and to accurately assess and characterise the risk.

METHODS

A three-step approach was developed to identify hypersensitivity or anaphylactic reactions: clinical trial database search, medical review, and adjudication to confirm or rule out cases. The database search strategy consisted of the narrow search for Standardized MedDRA Query (SMQ) Hypersensitivity, a modified MedDRA query based on SMQ Anaphylactic reaction, and pyrexia-related MedDRA Preferred Terms. The cases identified from the search were further medically reviewed taking into consideration the temporal relationship, seriousness, severity, course, and management of the events, action taken, and outcomes of adverse events. Those cases deemed to have potentially drug-related hypersensitivity were then adjudicated to be confirmed or ruled out.

RESULTS

The method was applied to a clinical trial database containing safety data for 421 patients treated with an investigational drug. Application of the methodology led to 19 hypersensitivity cases being identified. Of these, 12 were classified as immediate reactions and 7 as non-immediate reactions.

CONCLUSION

This three-step method provided a thorough and robust way to identify hypersensitivity reactions, including anaphylaxis, in a clinical trial database. This method could be applied to investigational drugs to improve early detection and monitoring of potential safety concerns, subsequent patient safety management strategies, and potentially programme-wide drug development decisions. Algorithmic tools and narrow and/or broad SMQs should be considered when evaluating safety concerns. The authors also recommend a revision of the MedDRA SMQ of Anaphylactic reaction.

Descriptive Analysis of Cross-Reactive Anaphylaxis as a Different Clinical Subtype of Nonsteroidal Anti-Inflammatory Drug (NSAID) Hypersensitivity

INTRODUCTION

The European Network of Drug Allergy and the European Academy of Allergy and Clinical Immunology have classified hypersensitivity reactions induced by nonsteroidal anti-inflammatory drugs (NSAIDs) into 5 phenotypes according to the pathophysiology, clinical manifestations, number of drugs involved, and the presence of underlying diseases. This classification does not include anaphylaxis as part of NSAID cross-reactivity. The objective of this study was to characterize a group of patients with anaphylactic NSAID cross-reactivity.

METHOD

This was a retrospective, descriptive, observational study. Patients who developed anaphylaxis to one NSAID plus another acute reaction (anaphylactic or not) to at least one other NSAID of a different chemical group were included. Demographic and clinical characteristics and the diagnostic approach were studied.

RESULTS

A total of 38 patients were included, 28 (73.7%) of whom were women. The mean age was 40 ± 17.7 years. The main organs affected in the anaphylactic reaction were the skin and the respiratory system, occurring in 35 (92.1%) and 33 (86.8%) patients, respectively. Thirty-two (84.3%) patients presented with cutaneous and respiratory involvement simultaneously. The main anti-inflammatory agent involved in anaphylactic reactions was acetylsalicylic acid in 9 (23.7%) patients, followed by dipyrone in 8 (21.1%). The most frequent allergic comorbidity was rhinitis in 20 (52%) patients. Skin tests were performed in 15 (39.5%) patients, showing positivity in 12 (80%), mainly to mites. A total of 36 of 38 patients were challenged with alternative drugs, and 35 (97.2%) tolerated meloxicam and/or etoricoxib.

CONCLUSION

In the present study, NSAID cross-anaphylaxis was more frequent in women, and acetylsalicylic acid and dipyrone were the main triggers. Rhinitis was the main allergic comorbidity, and there was a high incidence of atopy. The majority tolerated selective COX-2 NSAIDs.

Assessment of Confirmed Clinical Hypersensitivity to Rituximab in Patients Affected with B-Cell Neoplasia

Rituximab hypersensitivity reactions are rare but are one of the main causes of rituximab elimination from antilymphoma immunochemotherapy treatments. While the clinical picture may be indistinguishable from other infusion-related reactions, hypersensitivity reactions (HSR) do not disappear and instead become more intense with subsequent administrations. Objective. To describe the use of the 12-step protocol for desensitization to intravenous rituximab in clinical practice and the complementary study of a possible IgE-mediated HSR in the context of B-cell lymphoma treatment. Methods. A 12-step rituximab desensitization protocol was performed prospectively within clinical practice in 10 patients with a history of severe infusion reactions or in patients who had a repeated reaction at subsequent doses despite taking more intense preventive measures. Skin prick tests were performed at the time of reaction and at a later time to eliminate false negatives due to possible drug interference. Results. Overall, with the desensitization protocol, 70% of patients were able to complete the scheduled immunochemotherapy. Two patients had to discontinue the therapy due to clinical persistence and the third due to lymphoma progression. Intradermal tests with 0.1% rituximab were positive in only 20% of cases, demonstrating a mechanism of hypersensitivity. Conclusions. The 12-step desensitization protocol is very effective and assumable within healthcare practice. There is a need to determine the mechanism underlying the infusion reaction in a large proportion of cases due to the risk of future drug exposure.

Drug-Induced Anaphylaxis: An Update on Epidemiology and Risk Factors

Drug hypersensitivity is one of the most frequent causes of anaphylaxis, particularly in adults and in hospitalized patients. Drug-induced anaphylaxis (DIA) is also associated with more severe outcomes than other anaphylaxis triggers, and drugs are responsible for the majority of deaths due to anaphylaxis. We here review the current knowledge on the incidence, prevalence, drugs involved, mortality, and mortality risk factors for DIA. The incidence of both anaphylaxis and DIA seems to be increasing worldwide. Antibiotics and analgesics are the most frequently reported triggers of DIA. However, the importance of other drug groups should be taken into account, especially in particular settings (e.g., peri-operative and oncology). The identification of risk factors, geographical variables, and drugs associated with higher risk for DIA may improve the outcomes of this entity.