New Challenges in Drug Allergy: the Resurgence of Excipients

Purpose of Review

Allergy to excipients is a cause of multidrug allergy and if it is not taken into account, it can lead to unexpected severe reactions. If an excipient allergy is suspected, an accurate examination followed by algorithms is very important for a correct diagnosis and to give patients detailed information in order to avoid future reactions.

Recent Findings

In recent times, due to allergy COVID vaccine reactions, interest in excipients as polyethylene glycol derivatives (PEGs) has increased as a possible cause of drug and vaccine hypersensivity. In addition to PEGs many other excipients as gelatin, alpha-gal, protamine, benzalkonium chloride, and benzyl alcohol have been described as a cause of allergy to drugs and vaccines. For most excipients, the dilutions used for skin testing (ST) are not standardized and proper algorithms to reach a diagnosis are not available.

Summary

The purpose of this article is to review the excipients that may produce inmediate hypersensitivity drugs and vaccine reactions and update diagnostic procedures to reach an accurate diagnosis. We highlight the in vivo and in vitro diagnostic tests used in published reports and detail the dilution used for each excipient to perform ST in order to confirm this vital pathology and to prevent new reactions.

Anaphylaxis to drug excipients

In addition to the therapeutic agent, drugs contain excipients such as stabilizers, preservatives, solubilizers, or dyes, some of which are identical to additives in foods. Anaphylaxis to these excipients is probably an underestimated problem. After the first descriptions of anaphylactic reactions to drug excipients appeared more than 30 years ago, the number of corresponding reports has increased significantly over the years. However, a diagnostic gap exists in the clarification of drug allergic reactions when the index product is not known and/or is not available for testing. In the present work, individual excipients are presented as examples for which publications on anaphylaxis are available. Furthermore, the options of allergological testing both in vivo and in vitro are discussed. The pathogenesis of such reactions is still unresolved in many cases, and current concepts are briefly presented in the conclusion. With increasing knowledge about anaphylaxis to drug excipients, it is assumed that these can then be recognized more often and diagnostically clarified.

Anaphylaxie auf Hilfsstoffe in Arzneimitteln

Neben dem therapeutischen Agens enthalten Arzneimittel Hilfsstoffe als beispielsweise Stabilisatoren, Konservierungsstoffe, Löslichkeitsvermittler oder Farbstoffe, die teilweise identisch mit Zusatzstoffen in Nahrungsmitteln sind. Anaphylaxien auf diese Hilfsstoffe sind ein vermutlich unterschätztes Problem. Nachdem erste Beschreibungen anaphylaktischer Reaktionen auf Arzneimittelhilfsstoffe bereits vor über 30 Jahren auftauchten, hat die Zahl entsprechender Berichte in den letzten Jahren deutlich zugenommen. Eine diagnostische Lücke besteht allerdings in der Abklärung arzneimittelallergischer Reaktionen, wenn das Indexpräparat nicht bekannt ist und/oder nicht als Originalpräparat für Testungen zur Verfügung steht. In der vorliegenden Arbeit werden einzelne Hilfsstoffe exemplarisch vorgestellt, für die Publikationen zu Anaphylaxien vorliegen. Des Weiteren werden die Optionen allergologischer Testungen sowohl in vivo als auch in vitro besprochen. Die Pathogenese derartiger Reaktionen ist vielfach noch unklar, hier werden abschließend aktuelle Konzepte kurz vorgestellt. Mit zunehmendem Wissen über Anaphylaxien auf Arzneimittelhilfsstoffe ist davon auszugehen, dass diese auch vermehrt wahrgenommen und diagnostisch aufgeklärt werden können.

Zitierweise: Pfützner W. Anaphylaxis to drug excipients. Allergo J Int 2022;31:137-40

https://doi.org/10.1007/s40629-022-00214-9

Anaphylaxis to Excipients in Current Clinical Practice: Evaluation and Management

Excipients are the inactive ingredients in a drug or product that help to stabilize, preserve, or enhance the pharmacokinetics and bioavailability of the active ingredients. Excipient allergy is rare and hence often missed or misdiagnosed due to lack of awareness of the need to carefully review all drug ingredients. For the patient, excipient allergy can be frightening and potentially disruptive to health care delivery. This narrative review provides a clinically oriented, international, collaborative perspective on excipient allergy testing, management of future health care safety, limitations in our testing modalities, and barriers to optimal care.

Alpha-gal syndrome: the first report in Poland

Alpha-gal syndrome is an immunoglobulin E (IgE)-dependent allergy to galactose-α-1,3-galactose, resulting in a delayed anaphylactic reaction to red meat. The syndrome is causally linked to bites from ticks and associated with cross-reactivity to some drugs, e.g. cetuximab. Although cases of alpha-gal allergy have already been reported in a few European countries, to our best knowledge, no cases have been reported so far in Central-Eastern Europe. In the current report, we describe a case of alpha-gal syndrome diagnosed in Poland, to highlight the fact that it may occur in new geographic areas. Within three months, the described patient underwent five anaphylactic reactions with typical clinical manifestations. They developed a few hours after ingestion of red meat (pork, beef or mutton) and were preceded by tick bites. The level of specific IgE antibodies to alpha-gal reached 72.6 kAU/l, whereas the levels of specific IgE antibodies to other food allergens were within the reference range. As the onset of symptoms in this syndrome is usually delayed, numerous cases may be identified as idiopathic anaphylaxis, while early diagnosis is indispensable to avoid potentially life-threatening complications.

Alpha-gal syndrome. Allergy to red meat and gelatin

INTRODUCTION

Alpha-gal syndrome is a potentially severe food allergy caused by the presence of alpha-gal-specific IgE. The aim of this study is to describe our series of 13 patients.

MATERIAL AND METHODS

This work is a retrospective study of patients diagnosed in 2016 and 2017. Skin tests were performed with commercial extract and gelaspan as well as specific IgE determination for alpha-gal and different types of meat.

RESULTS

Thirteen patients diagnosed with alpha-gal syndrome were analyzed; 9 of them had anaphylaxis, 6 of whom had been diagnosed with idiopathic anaphylaxis. All had a positive skin test with gelaspan, though this was not true with the commercial extracts, whose results were less conclusive.

CONCLUSIONS

We believe that a diagnosis of idiopathic anaphylaxis may prevent the identification of patients with alpha-gal syndrome. The gelaspan skin test is more useful than commercial extracts.

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.

Alpha-gal syndrome: An emerging cause of food and drug allergy

Alpha-gal syndrome (AGS) describes a wide spectrum of hypersensitivity reactions mediated by specific IgE to the α-gal epitope (galactose-α-1,3-galactose) ubiquitously expressed on glycolipids/glycoproteins of most mammals. This fascinating new entity has completely changed the paradigms of allergy as allergic response is directed against an oligosaccharide and the reactions can be both immediate and delayed. They appear to be stimulated only by tick bites which induce production of α-gal specific IgE antibodies that lead to (at times fatal) hypersensitivity response. AGS is completely different to previously described anaphylaxis to tick saliva. It provides unique insight into the interplay between different arms of the immune system and the role of ectoparasites in the development of anaphylaxis to food and medication in patients at risk of tick bites including travellers. This review summarises recent advances in our understanding of its clinical presentation, pathomechanism and role of various tick species in the development of AGS.

Galactose-α-1,3-galactose (alpha-gal) allergy: first pediatric case in a series of patients in Spain

INTRODUCTION AND OBJECTIVES

Allergy to galactose-α-1,3-galactose (alpha-gal) is a peculiar form of food allergy generally manifesting as an anaphylactic reaction hours after mammalian meat consumption, due to the presence of specific IgE against this oligosaccharide. In addition, immediate anaphylaxis may develop after exposure to other sources of alpha-gal, such as monoclonal antibody cetuximab, vaccines, plasma expanders or anti-snake venoms. Sensitization to alpha-gal has also been implicated in the rapid degeneration of biological valve implants, and recognized as a cause of occupational disease in cattle raisers. The implication of tick bites in this type of sensitization has been accepted by all the research groups dedicated to this disease.

PATIENTS AND METHOD

The present study describes the clinical and sensitization characteristics of 39 patients diagnosed with alpha-gal allergy in the hospitals of our province (Lugo, Monforte de Lemos and Burela, Spain).

RESULTS

Most patients were middle-age males. Of note, is the fact that the series includes the first pediatric patient reported in Spain to date. The predominant clinical manifestations were urticaria or delayed anaphylaxis after consumption of mammalian meat. Seventy-four percent of the patients reported having suffered a previous tick bite, and the clinical presentation of anaphylaxis was significantly more prevalent in those with a persistent local reaction following the bite than in those with no such reaction (p = 0.032).

CONCLUSIONS

A review is also made of the disorder which, due to its variable clinical expression, is referred to as alpha-gal syndrome. The study concludes that a diagnosis of alpha-gal allergy should be considered in patients with urticaria-anaphylaxis of uncertain origin or manifesting after the administration of vaccines or products of bovine/porcine origin.

On the cause and consequences of IgE to galactose-α-1,3-galactose: A report from the National Institute of Allergy and Infectious Diseases Workshop on Understanding IgE-Mediated Mammalian Meat Allergy

The mammalian meat allergy known as the "α-Gal syndrome" relates to IgE specific for galactose-α-1,3-galactose (α-Gal), an oligosaccharide that is present in cells and tissues of nonprimate mammals. The recognition of delayed reactions to food derived from mammals in patients with IgE to α-Gal and also the association with tick bites have been increasing worldwide. In 2018, the National Institute of Allergy and Infectious Diseases, Division of Allergy, Immunology and Transplantation, sponsored a workshop on this emerging tick-related disease. International experts from the fields of tick biology, allergy, immunology, infectious disease, and dermatology discussed the current state of our understanding of this emerging medical condition. The participants provided suggestions for specific research priorities and for the development of resources to advance our knowledge of the mechanisms, diagnosis, management, and prevention of this allergic disease. This publication is a summary of the workshop and the panel's recommendations are presented herein.

Diagnosis and Management of Patients with the α-Gal Syndrome

The galactose-α-1,3-galactose (α-Gal) syndrome has many novel features that are relevant to diagnosis and management. In most cases, the diagnosis can be made on a history of delayed allergic reactions to mammalian meat and the blood test for IgE to the oligosaccharide α-Gal. In general, the diagnosis also dictates the primary treatment, that is, avoiding mammalian meat and also dairy in some cases. In the United States, the lone star tick is the primary cause of this disease, but different ticks are responsible in other countries. Blood levels of IgE to α-Gal often drop in patients who avoid recurrent tick bites, but the rate of decline is variable. Similarly, the delay before reactions is variable and the severity of the allergic reactions is not predicted by the delay or the titer of specific IgE. Some mammalian-derived products such as heart valves, gelatin-based plasma expanders, and pancreatic enzymes are relevant to only select patient groups. A minority of cases may benefit from avoiding a wide range of products that are prepared with mammalian-derived constituents, such as gelatin. This review focuses on the nature of the syndrome, common challenges in diagnosis and management, and also gaps in our current knowledge that would benefit from additional investigation.

Preventing iatrogenic gelatin anaphylaxis

OBJECTIVE

To assess the iatrogenic risks of gelatin allergy and identify resources for patient management.

DATA SOURCES

A literature review was performed using PubMed and public databases provided by the National Library of Medicine.

STUDY SELECTIONS

Reports of iatrogenic gelatin allergy associated with vaccines, hemostatic agents, intravenous colloids, medicinal capsules, and intraoperative surgical supplies.

RESULTS

Gelatin ingredients may not be identified by electronic medical record safeguards, and an exhaustive listing of potential iatrogenic exposures is elusive. The National Library of Medicine AccessGUDID (https://accessgudid.nlm.nih.gov/) can be a useful resource in evaluating medical devices for gelatin content. Unexpected sources of iatrogenic gelatin exposure include hemostatic agents, vascular grafts, intravascular cannulas, bone replacement implants, and emergency resuscitation fluids.

CONCLUSION

Vigilance is important within medical systems to avoid inadvertent gelatin exposure when caring for patients with gelatin allergy. Additional safeguards are needed to remove latent health care system errors that fail to prevent gelatin administration in this at-risk population.

Role and Mechanism of Galactose-Alpha-1,3-Galactose in the Elicitation of Delayed Anaphylactic Reactions to Red Meat

Purpose of Review

The alpha-Gal (α-Gal) syndrome is characterized by the presence of IgE antibodies directed at the carbohydrate galactose-alpha-1,3-galactose (α-Gal). In this article, we review the presence of α-Gal in food and non-food sources; we discuss the evolutionary context of the antibody response to α-Gal and highlight immune responses to α-Gal and other carbohydrates.

Recent findings

IgE antibodies have been associated with delayed allergy to red meat. In addition to food, drugs, and other products of animal origin are increasingly perceived as a risk for patients sensitized to α-Gal. The link between tick bites and anti-α-Gal IgE-antibody production that has been established first by epidemiological studies has now been confirmed in mouse models.

Summary

The anti-α-Gal immune response is complex and characterized by a unique feature. IgM and IgG antibodies have been found to confer protection against pathogens whereas the IgE-response to α-Gal is detrimental and causes severe reactions upon exposure to mammalian meat and other products.