What Does a Red Meat Allergy Have to Do With Anesthesia? Perioperative Management of Alpha-Gal Syndrome

Alpha-Gal Syndrome and Cardiac Surgery

Galactose-alpha-1,3-galactose (alpha-gal) is a carbohydrate expressed by all mammals except for humans and certain old-world primates. It can be found in a plethora of products derived from mammals, including milk, organs, skeletal muscle and gelatin, in addition to products prepared with mammalian cells or constituents. In the late 2000s, an association between tick bites and the development of immunoglobulin E antibodies to the alpha-gal carbohydrate was discovered. The term "alpha-gal syndrome" (AGS) was then coined to describe allergic reactions to mammalian meat or other alpha-gal-containing products derived from mammals. Symptoms are often delayed several hours from consumption and can be urticarial and/or gastrointestinal. Medications and bioprosthetic inserts derived from mammals were also noted to cause allergic reactions in affected patients. Cardiac surgery, in particular, is considered high risk, given that unfractionated heparin has a bovine or porcine origin and is administered in large doses for cardiopulmonary bypass. Bioprosthetic valves have similar origins and risks. Awareness of AGS in cardiac surgery patients can lead to decreased risk preoperatively and inform management perioperatively and postoperatively. In this narrative review, we have reviewed the published literature relevant to AGS in patients undergoing cardiac surgery and shared our treatment approach.

Neurosurgical Management of Patients with Alpha-Gal Syndrome

Alpha-gal syndrome (AGS) is an immunoglobulin E-mediated hypersensitivity to galatcose-alpha-1,3-galactose (alpha-gal), a carbohydrate compound present in nonprimate mammalian products. Initial exposure to alpha-gal most often occurs through a tick bite, most commonly the lone star tick in the United States. Repeated exposure to alpha-gal may elicit severe allergic reactions, including anaphylaxis. The allergy restricts dietary intake and may significantly impact perioperative risk, as many medications, anesthetics, and intraoperative surgical products utilize bovine or porcine-derived agents, including those containing magnesium stearate, glycerol, and gelatin. Here, we review the perineurosurgical care of two individuals with AGS and highlight pertinent clinical practices and perioperative management of these patients.

Perioperative Considerations in Alpha-Gal Syndrome: A Review

Galactose-⍺-1, 3-galactose (alpha-gal) is an oligosaccharide found in mammalian tissues that causes allergic reactions in patients with alpha-gal syndrome (AGS). AGS is a hypersensitivity reaction notable for both immediate and delayed allergic and anaphylactic symptoms. As a tick-based disease, AGS has gained increasing prevalence across the United States and can have a significant influence on which medications are safe for patients. Many medications used within the operating room and intensive care units have inactive ingredients that can be mammalian-derived and therefore should be vetted before administering to patients with AGS. Management of patients with AGS involves diligent action in the preoperative and perioperative settings to reduce patient exposure to potentially harmful medications. In conducting a comprehensive risk stratification assessment, the anesthesia team should identify any at-risk patients and determine which medications they have safely tolerated in the past. Despite obtaining a complete history, not all patients with AGS will be identified preoperatively. The perioperative team should understand which common medications pose a risk of containing alpha-gal moieties (e.g., heparins, gelatin capsules, vaccines, lidocaine patches, surgifoam, etc.​​). For this reason, this paper includes a compendium of common anesthetic medications that have been cross-referenced for ingredients that have the potential to cause an AGS reaction. Any potentially unsafe medications have been identified such that medical providers can cross-reference with the ingredients listed at their respective institutions.

Alpha-gal syndrome-Food or drug allergy: A case report

Alpha-gal syndrome is an immunoglobulin E-mediated hypersensitivity characterized by delayed allergic reactions to ingested products containing alpha-gal carbohydrate. We present a patient with recurrent urticaria and suspected repaglinide hypersensitivity, who was eventually diagnosed with alpha-gal syndrome, wanting to emphasize possible drug allergy misdiagnosis and required caution with the medication choice.

Perioperative implications of patients with alpha gal allergies

Alpha Gal Syndrome (AGS) is an emerging immune response to mammalian products (MP) containing the oligosaccharide galactose-α-1,3 galactose (α-Gal) which includes meats and inactive ingredients in certain medications. This becomes clinically important in the perioperative realm as MPs are commonly found in the operating room, and pre- and post-operative settings, and can trigger responses as severe as anaphylaxis. In this review, authors discuss the epidemiology, diagnosis and treatment of AGS reactions. Additionally, strategies are explored in order to screen and prevent exposure to MP with a multidisciplinary approach. While this emerging allergy is still not fully understood, it is of paramount importance that all anesthesia providers recognize the implications of MP exposure in AGS patients and ultimately prevent harm in this highly vulnerable population.

The Meat of the Matter: Understanding and Managing Alpha-Gal Syndrome

Alpha-gal syndrome is an unconventional food allergy, characterized by IgE-mediated hypersensitivity responses to the glycan galactose-alpha-1,3-galactose (alpha-gal) and not to a food-protein. In this review, we discuss how alpha-gal syndrome reframes our current conception of the mechanisms of pathogenesis of food allergy. The development of alpha-gal IgE is associated with tick bites though the possibility of other parasites promoting sensitization to alpha-gal remains. We review the immune cell populations involved in the sensitization and effector phases of alpha-gal syndrome and describe the current understanding of why allergic responses to ingested alpha-gal can be delayed by several hours. We review the foundation of management in alpha-gal syndrome, namely avoidance, but also discuss the use of antihistamines, mast cell stabilizers, and the emerging role of complementary and alternative therapies, biological products, and oral immunotherapy in the management of this condition. Alpha-gal syndrome influences the safety and tolerability of medications and medical devices containing or derived from mammalian products and impacts quality of life well beyond food choices.

Initiating Psychotropic Treatment in a Patient With Alpha-Gal Syndrome

Alpha-gal syndrome, which is typically acquired by a tick bite, is an IgE-mediated immune response to galactose-alpha-1,3-galactose (alpha-gal), an oligosaccharide in most mammalian tissue. This report describes a 29-year-old Caucasian female with comorbid alpha-gal syndrome who presented to the inpatient psychiatric unit after an intentional overdose. Because of the patient’s alpha-gal syndrome, the treatment team worked with the hospital pharmacy to evaluate treatment options that did not contain mammalian products. After carefully reviewing the ingredients of suitable medications on formulary, the patient was started on a generic sertraline formulation that was free of mammalian derivatives. At the time of discharge, the patient reported significant symptom improvement and was free of symptoms suggesting an alpha-gal allergic reaction. This case illustrates the challenges of starting psychiatric medications in a patient with comorbid alpha-gal syndrome.

Current and Future Strategies for the Diagnosis and Treatment of the Alpha-Gal Syndrome (AGS)

The α-Gal syndrome (AGS) is a pathognomonic immunoglobulin E (IgE)-mediated delayed anaphylaxis in foods containing the oligosaccharide galactose-α-1,3-galactose (α-Gal) such as mammalian meat or dairy products. Clinical presentation of AGS can also comprise immediate hypersensitivity due to anticancer therapy, gelatin-containing vaccines or mammalian serum-based antivenom. The IgE initial sensitization is caused by hard-bodied tick bites and symptomatic individuals typically develop delayed pruritus, urticaria, angioedema, anaphylaxis, malaise or gut-related symptoms. Due to inapparent presentation, delayed reactions and a wide variety of patients´ clinical history, the AGS diagnosis and treatment remain challenging. This review covers not only current diagnostic methods used for AGS such as the skin prick test (SPT), the oral food challenge (OFC), anti-α-Gal IgE levels measurement and the basophil activation test (BAT), but also potentially relevant next-generation diagnostic tools like the mast cell activation test (MAT), the histamine-release (HR) assay, omics technologies and model-based reasoning (MBR). Moreover, it focuses on the therapeutical medical and non-medical methods available and current research methods that are being applied in order to elucidate the molecular, physiological and immune mechanisms underlying this allergic disorder. Lastly, future treatment and preventive tools are also discussed, being of utmost importance for the identification of tick salivary molecules, with or without α-Gal modifications, that trigger IgE sensitivity as they could be the key for further vaccine development. Bearing in mind climate change, the tick-host paradigm will shift towards an increasing number of AGS cases in new regions worldwide, which will pose new challenges for clinicians in the future.

Meat Allergy: A Ticking Time Bomb

Food allergies are relatively prevalent, but mammalian meat allergy remains uncommon and represents an important, potentially acute healthcare risk. This risk is partly because both clinicians and the public lack awareness of this serious allergy, which is unique in three important ways: it incurs a delayed reaction, it is induced by a carbohydrate rather than a protein, and it is linked to tick bites. Although various symptoms are possible, its unique presentation means that mammalian meat allergy is often presented to the dermatologist. We review this challenging subject, which is particularly salient considering the unique connection between ticks and mammalian meat allergy, the expanding tick territory, and the dependency by so many on meat products, not only in the diet but also in medications and medical devices.

Clinical Issues-April 2022

Perioperative care of the patient with alpha-gal syndrome Key words: alpha-gal syndrome (AGS), red meat allergy, allergic reaction, mammalian-derived ingredients, gelatin. Overnight storage of sterile supplies Key words: sterile supplies, event-related sterility, terminal cleaning, damp dusting, instrument table. Unsterile medication cartridges Key words: dental cartridge, local anesthesia, lidocaine, alcohol, sterile field. Personnel traffic into the OR Key words: OR traffic, door openings, airflow, environmental contamination, automatic doors.

Demystifying α-gal syndrome: identification and risk management in the perioperative setting

PURPOSE OF REVIEW

α-Gal syndrome is among a vexing perioperative consideration for anesthesiologists. Commonly referred to as 'red meat allergy', α-Gal syndrome is precipitated by a lone star tick bite resulting in the formation of immunoglobulin E (IgE) antibodies against the tick salivary glycoproteins and noncatarrhine mammalian tissue.

RECENT FINDINGS

Up to 20% of the population in the southeastern United States may test positive for IgE antibodies to α-Gal. Increasingly, recognition of α-Gal syndrome as an immune response to red meat consumption and certain drugs, many of which may be administered within the perioperative period, has led to greater awareness of the insidious nature of its presentation - from mild urticaria and gastrointestinal symptoms to severe anaphylaxis.

SUMMARY

With the increasing prevalence and identification of α-Gal syndrome, a safe and tailored perioperative process is needed to integrate a pathway that involves multidisciplinary communication, robust information sharing platform, and a structured peri-procedure management.

A retrospective evaluation of heparin product reactions in patients with alpha-gal allergies

BACKGROUND

Alpha-gal allergy, also known as red meat allergy or alpha-gal syndrome, can present after bites of certain tick species that contain galactose-alpha-1,3-galactose (alpha-gal) carbohydrate. Following this exposure, patients may develop an allergic reaction after mammalian meat consumption. Some heparin products are derived from porcine intestinal tissue, and it is therefore possible that administering these medications to a patient with an alpha-gal allergy may trigger a reaction.

OBJECTIVE

The purpose of this study was to evaluate the incidence of reactions to porcine heparin products in patients with an alpha-gal allergy.

METHODS

A retrospective case series was conducted by review of electronic medical record data. Patients included were between the ages of 18 and 89 years, with a documented alpha-gal or red meat allergy and an admission to a hospital in the Sentara Healthcare system. The primary outcome was the incidence of allergic reactions upon exposure to heparin products in patients with a documented alpha-gal allergy.

RESULTS

Patients with a documented alpha-gal allergy received a heparin product in 57 of 158 hospital visits (36.1%). Heparin products were tolerated in 56 of the 57 visits (98.3%). The incidence of an alpha-gal reaction to unfractionated heparin was 2.6% (1/39) while the incidence of an alpha-gal reaction to enoxaparin was 0% (0/22).

CONCLUSION AND RELEVANCE

Heparin products were associated with a low incidence of alpha-gal reactions among patients with documented alpha-gal allergy. It is possible that enoxaparin poses less of a risk for reaction in these patients compared to unfractionated heparin.

Interdisciplinary Significance of Food-Related Adverse Reactions in Adulthood

Background: Adults frequently interpret food-associated adverse reactions as indicators of a food allergy. However, the public perception of food allergy may differ from a clinician's point of view. The prevalence of patient-reported food allergy tends to be higher than physician-confirmed cases. Dermatological manifestations (urticaria, pruritus, dermatitis, and edema) are frequently reported by patients. Objective: The aim of this study was to describe patient-reported symptoms related to suspected food allergies and particularly to characterize and highlight the volume of patients who visit Budapest allergy clinics with suspected food allergies. Methods: In this prospective study, adult (≥18 years) patients were examined at the Allergology Outpatient Unit of the Dept. of Dermatology, Venereology, and Dermatooncology, Semmelweis University, Budapest. The examination included a detailed medical history; physical examination; and when necessary the measurement of allergen-specific serum immunoglobulin E (IgE) levels. Results: Data from 501 patients (393 women, 108 men) were analyzed. Intolerance to dietary biogenic amines occurred in 250 cases (250/501, 50%). Oral allergy syndrome was confirmed in 71 patients (71/501, 14%). Allergy to food preservatives was diagnosed in 14 (14/501, 3%) cases by a dermatologist-allergist specialist. Five individuals (5/501, 1%) were diagnosed with IgE-mediated food allergy. In some cases (28/501, 6%), edema-inducing/enhancing side effects of drugs were observed which patients had misattributed to various foods. Among the food groups considered to be provoking factors, the most frequently mentioned were fruits (198/501, 40%), milk/dairy products (174/501, 35%), and nuts/oilseeds (144/501, 29%). Overwhelmingly, urticaria (47%) was the most common dermatological diagnosis, followed by dermatitis (20%) and allergic contact dermatitis (8%). Conclusion: Improvement is needed in food allergy, food intolerance, and general nutritional knowledge among the general public. According to our data, perceived/self-reported food allergies were overestimated by adults when compared against physician-confirmed food allergies; however, other diseases potentially responsible for food-related problems were underestimated. The prevalence of oral allergy syndrome was high in the cohort. Intolerance to dietary biogenic amines was common, and although the role of dietary histamine and biogenic amine is not entirely understood in eliciting patients' symptoms, improvements in complaints were reported during the control visits.

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.