Component-resolved diagnosis in anaphylaxis

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.

Pediatric Anaphylaxis: A 20-Year Retrospective Analysis

BACKGROUND

Anaphylaxis is a steadily increasing global problem defined as an acute hypersensitivity multisystem reaction that is potentially fatal. In the pediatric age, the leading cause is food. In other allergic diseases, intrinsic heterogeneity has been reported in the clinical presentation, severity, and triggers of anaphylaxis. This study analyzes the features and management approach of the anaphylactic reactions in children evaluated at the pediatric clinic in Pavia.

MATERIALS AND METHODS

A retrospective study was conducted on patients with anaphylaxis between 2001 and 2021.

RESULTS

A total of 148 patients with a median age of 5 years were enrolled, and 80% of the patients had other atopic comorbidities that were correlated with the severity of anaphylaxis. The main trigger of anaphylaxis was food. Most reactions involved mucocutaneous, respiratory, and gastrointestinal systems, and occurred at home. Adrenaline was administered only in a minority of cases.

CONCLUSIONS

Considering that anaphylaxis is a potentially life-threatening condition requiring prompt management, the use of adrenaline should be implemented. Our data also suggest the importance of educating and spreading awareness of anaphylactic management within the medical community.

Ultrasensitive detection of specific IgE based on nanomagnetic capture and separation with a AuNP-anti-IgE nanobioprobe for signal amplification

The accurate detection of allergen specific IgE (sIgE) is fundamental in the diagnosis of allergic diseases. The present commercial platforms fail to meet the need for personalized diagnosis, due to the unsuitable allergen-fixation model and large amounts of serum consumption. In this work, we developed a nano-capturer Fe₃O₄@SiO₂-NTA with an enhanced signal by taking advantage of a AuNP-anti-IgE nanobioprobe for precise and highly sensitive quantification detection of sIgE in serum of allergic patients. The recombinant allergen was immobilized on Fe₃O₄@SiO₂-NTA through the interaction between its His-tag and Ni-NTA, which is more consistent with the real binding mode of allergens with sIgE in vivo than the present clinically used allergen-fixation methods. Numerous horseradish peroxidase (HRP)-labeled anti-IgE were modified onto one AuNP to detect the sIgE probed by Fe₃O₄@SiO₂-NTA@rCanf1. Once one anti-IgE binds to sIgE, other HRP-labeled anti-IgE modified on the same AuNP would all create signals, resulting in a significantly amplified chemiluminescence (CL) signal. Our results showed that this immunosensor could realize fast, accurate, low-cost and highly sensitive sIgE detection in serum samples. In vitro experiments demonstrated a 0.02 ng mL^-1 detection limit, which was lower than that of any standard analyzer used for allergy immunoassays. Furthermore, our method was utilized for the diagnosis of clinical samples. The results were in good agreement with those obtained by the clinical gold standard ImmunoCAP, with 1000 times less serum consumption than ImmunoCAP. Therefore, the presented immunosensor holds great promise to improve clinical sIgE quantitative detection and constitutes a potentially useful tool for clinical diagnosis and subsequent individual treatment of allergic diseases.

Food Allergy Insights: A Changing Landscape

The panorama of food allergies (FA) has changed profoundly in recent years. In light of recent advances in knowledge of pathogenetic mechanisms and a greater attention to the multifaceted range of possible clinical manifestations, there is a need for a critical review of past classifications. Changes in nutrition, environment and lifestyles around the world are modifying the global FA epidemiology and new FA phenotypes are also emerging. Furthermore, both biotechnological advances in this field and recent personalized therapies have improved the diagnostic and therapeutic approach to FA. Consequently, both the prevention and clinical management of FA are rapidly changing and new therapeutic strategies are emerging, even revolutionizing the current medical practice. Given the significant increase in the prevalence of FA in recent years, the objective of this review is to provide an updated and complete overview of current knowledge in its etiopathogenesis, diagnostics and therapy, useful not only for a better understanding of this frequent and complex pathology but also for practical guidance in its clinical management.

A WAO - ARIA - GA2LEN consensus document on molecular-based allergy diagnosis (PAMD@): Update 2020

Precision allergy molecular diagnostic applications (PAMD@) is increasingly entering routine care. Currently, more than 130 allergenic molecules from more than 50 allergy sources are commercially available for in vitro specific immunoglobulin E (sIgE) testing. Since the last publication of this consensus document, a great deal of new information has become available regarding this topic, with over 100 publications in the last year alone. It thus seems quite reasonable to publish an update. It is imperative that clinicians and immunologists specifically trained in allergology keep abreast of the new and rapidly evolving evidence available for PAMD@.

PAMD@ may initially appear complex to interpret; however, with increasing experience, the information gained provides relevant information for the allergist. This is especially true for food allergy, Hymenoptera allergy, and for the selection of allergen immunotherapy. Nevertheless, all sIgE tests, including PAMD@, should be evaluated within the framework of a patient's clinical history, because allergen sensitization does not necessarily imply clinical relevant allergies.

New Perspectives in Food Allergy

The improvement of the knowledge of the pathophysiological mechanisms underlying the tolerance and sensitization to food antigens has recently led to a radical change in the clinical approach to food allergies. Epidemiological studies show a global increase in the prevalence of food allergy all over the world and manifestations of food allergy appear increasingly frequent also in elderly subjects. Environmental and nutritional changes have partly changed the epidemiology of allergic reactions to foods and new food allergic syndromes have emerged in recent years. The deepening of the study of the intestinal microbiota has highlighted important mechanisms of immunological adaptation of the mucosal immune system to food antigens, leading to a revolution in the concept of immunological tolerance. As a consequence, new prevention models and innovative therapeutic strategies aimed at a personalized approach to the patient affected by food allergy are emerging. This review focuses on these new perspectives and their practical implications in the management of food allergy, providing an updated view of this complex pathology.

IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper

Currently, testing for immunoglobulin E (IgE) sensitization is the cornerstone of diagnostic evaluation in suspected allergic conditions. This review provides a thorough and updated critical appraisal of the most frequently used diagnostic tests, both in vivo and in vitro. It discusses skin tests, challenges, and serological and cellular in vitro tests, and provides an overview of indications, advantages and disadvantages of each in conditions such as respiratory, food, venom, drug, and occupational allergy. Skin prick testing remains the first line approach in most instances; the added value of serum specific IgE to whole allergen extracts or components, as well as the role of basophil activation tests, is evaluated. Unproven, non-validated, diagnostic tests are also discussed. Throughout the review, the reader must bear in mind the relevance of differentiating between sensitization and allergy; the latter entails not only allergic sensitization, but also clinically relevant symptoms triggered by the culprit allergen.

Accurate assessment of alpha-gal syndrome using cetuximab and bovine thyroglobulin-specific IgE

SCOPE

IgE against galactose-α-1,3-galactose (α-Gal) causes alpha-gal syndrome. Bovine thyroglobulin (BTG) and cetuximab share this epitope. We aimed to determine the utility of specific IgE (sIgE) against cetuximab as compared to BTG for diagnosing alpha-gal syndrome.

METHODS AND RESULTS

Twelve patients with alpha-gal syndrome, 11 patients with immediate beef or pork allergy, 18 asymptomatic individuals with meat sensitization, and 10 non-atopic subjects were enrolled. We checked the levels of sIgE against BTG and cetuximab using the streptavidin CAP assay. Additionally, IgE reactivity to BTG and cetuximab was assessed by immunoblotting. All alpha-gal syndrome patients had a high concentration of sIgE against BTG, and cetuximab. In contrast to alpha-gal syndrome, patients with immediate allergic reactions to meat consumption and those with asymptomatic sensitization had significantly lower concentration of BTG and cetuximab sIgE, and a high prevalence of sIgE against bovine or porcine serum albumin. Although the concentration of sIgE against alpha-gal was lower in individuals with asymptomatic sensitization, IgE immunoblotting showed the presence of sIgE against α-Gal in this group.

CONCLUSION

Differentiation of alpha-gal syndrome from patients with immediate allergy to meat consumption or asymptomatic sensitization requires quantification of cetuximab- or BTG-induced sIgE via detection of IgE for α-gal.