The alpha-gal story: lessons learned from connecting the dots

Glycoproteomic and single-protein glycomic analyses reveal zwitterionic N-glycans on natural and recombinant proteins derived from insect cells

Insect cells are a convenient cell factory to produce recombinant glycoproteins. Their glycosylation potential is believed to be simple, needing primarily addition of glycosyltransferases to humanize the recombinant products. In this study, the native glycoproteome of Spodoptera frugiperda Sf9 and Trichoplusia ni High Five cells, examined using an LC-MS/MS approach, revealed not only which proteins are N-glycosylated, but indicated that the N-glycomes contain novel glucuronylated and phosphorylcholine-modified glycans, in addition to typical oligomannosidic and fucosylated structures. These data were corroborated by a parallel MALDI-TOF MS/MS analysis of N-glycosidase-released oligosaccharides. Molecular modelling analysis of one endogenous Sf9 glycoprotein correlated the occurrence of complex and oligomannosidic N-glycans with the accessibility of the occupied N-glycosylation sites. Further, we showed that the N-glycans of influenza haemagglutinins and SARS-CoV-2 spike glycoprotein produced in Spodoptera cells possess a number of glycan structures modified with phosphorylcholine, but core difucosylation was minimal; in contrast, the Trichoplusia-produced haemagglutinin had only traces of the former type, while the latter were dominant. Detection of phosphorylcholine on these glycoproteins correlated with binding to human C-reactive protein. In conclusion, not just oligomannosidic or truncated paucimannosidic N-glycans, but structures with immunogenic features occur on both natural and recombinant glycoproteins derived from insect cell lines.

Perioperative management of alpha-gal syndrome in bariatric surgery: A case study of venous thromboembolism prophylaxis

BACKGROUND

Alpha-gal syndrome (AGS) is a tick-borne allergic condition triggered by galactose-alpha-1,3-galactose, a carbohydrate found in mammalian products. This case report highlights the perioperative challenges of managing AGS in a patient undergoing Roux-en-Y gastric bypass, a common bariatric surgical procedure.

CASE SUMMARY

A 53-year-old male with AGS was scheduled for robotic-assisted Roux-en-Y gastric bypass with potential hiatal hernia repair. The patient exhibited severe sensitivity to beef but lower reactivity to pork products, complicating the use of porcine-derived heparin for venous thromboembolism prophylaxis. After careful evaluation, low-molecular-weight heparin (enoxaparin) was selected as the anticoagulant, with 40 mg administered preoperatively. The patient underwent surgery without adverse reactions or bleeding complications.

PRACTICE IMPLICATIONS

This case underscores the complexities of AGS management in surgical settings, particularly regarding the selection of anticoagulants. While nonporcine alternatives exist, their safety and efficacy in bariatric surgery remain underexplored. The successful use of enoxaparin in this case suggests that a tailored approach, supported by multidisciplinary collaboration, can mitigate risks. This report highlights the need for further research to establish guidelines for anticoagulation in patients with AGS undergoing surgery. Enhanced awareness and individualized care are critical to ensuring optimal outcomes in this unique patient population.

Highly variable aggregation and glycosylation profiles and their roles in immunogenicity to protein-based therapeutics

Production of antibodies against protein-based therapeutics (e.g., monoclonal antibodies (mAbs)) by a recipient's immune system can vary from benign symptoms to chronic neutralization of the compound, and in rare cases, a lethal cytokine storm. One critical factor that can induce or contribute to an anti-drug antibody (ADA) response is believed to be the presence of aggregated proteins in protein-based therapeutics. There is a high level of variability in the aggregation of different proteins, which adds to the complexity in understanding the immune response to these drugs. Furthermore, the level of glycosylation of proteins, which increases drug stability, functionality, and serum half-life, is highly variable and may influence their immunogenicity. Considering the abundance of literature on the effect of aggregation and glycosylation on the immunogenicity of protein-based therapeutics, this review aims to summarize the current knowledge and clarify the immunogenic effects of different protein-based therapeutics such as mAbs. This review focuses on the properties of aggregated proteins and elucidates their relationship with immunogenicity. The contribution of different immune cell subsets and the mechanisms in aggregation-induced immunogenicity are also reviewed. Finally, the potential effects of each glycan, such as sialic acid, mannose, and fucose, on protein-based therapeutics' immunogenicity and stability is discussed.

Alpha-Gal Syndrome: A Review for the General Internist

Alpha-gal syndrome develops in some individuals who have had tick bites which result in IgE responses to alpha-gal, a carbohydrate not found in humans. Patients with alpha-gal syndrome develop symptoms when they ingest mammalian meat, which contains this oligosaccharide. Often the response to this exposure is delayed and occurs 2 to 6 h post-ingestion. Symptoms can include skin rashes, urticaria, gastrointestinal symptoms, and occasionally anaphylaxis. In some patients, the initial site of the skin reaction is at the location of the prior tick bite. The frequency of the syndrome is uncertain but the geographic distribution is predominantly in areas with the lone star tick. The diagnosis depends on careful attention to the time interval between the ingestion of meat and the development of the symptoms. In addition, a history of prior tick bites is important for considering this diagnosis. Diagnostic studies include skin tests, serologic tests for specific IgE, and food challenges, with varying risks for anaphylaxis. The treatment of patients with acute presentations frequently includes intramuscular epinephrine, oral antihistamines, and corticosteroids. Long-term management involves diet modification with the elimination of meat. Patients can also have adverse reactions to medications, such as set cetuximab, heparin, monoclonal antibodies, and pancreatic enzymes, and clinicians will likely have difficulty identifying these reactions. If patients have a good response to diet modification and have a significant reduction in their specific IgE level to alpha-gal, they potentially can resume eating meat in their diet. This should be done under the direction of a specialist.

α-Galactose Syndrome Cases within the Prisma Health System, South Carolina

OBJECTIVES

Humans can develop a vector-associated allergy to galactose-α-1,3-galactose (α-gal) a polysaccharide found in mammalian meats and by-products, resulting in α-gal syndrome (AGS). Amblyomma americanum tick bites have been implicated in AGS development in the United States, but the AGS clinical burden in South Carolina is not well understood. Because A. americanum is the predominant tick species in the state and large AGS cohorts exist in neighboring states, the potential for AGS clinical cases in South Carolina exists. Increased understanding of high-incidence geographical clusters is critical for clinical and public education given the potential for severe anaphylaxis.

METHODS

We conducted a 5-year retrospective chart abstraction of AGS patient cases serologically confirmed within the state's largest healthcare system to characterize this condition in South Carolina's Upstate and Midlands regions.

RESULTS

From October 2017 to February 2023, 50 patients were serologically diagnosed as having AGS within the Prisma Health system. Cohort demographics were mostly older, White males, and Black patients were significantly underrepresented in the AGS caseload (P = 0.0004). Immunosuppressing comorbidities and cooccurring allergies were common.

CONCLUSIONS

This article presents the first clinical AGS case series in South Carolina, warranting further clinical and public education and a need for continued clinical research on this emerging tick-associated condition.

Alpha-Gal Syndrome: An Emerging Tick-Borne Allergy to Red Meat

Alpha-gal syndrome (AGS) is a delayed-onset food allergy triggered by an immune response to galactose-α-1,3-galactose (alpha-gal), a carbohydrate associated with Lone Star tick bites. A 45-year-old female presented with a 9-month history of nausea and abdominal pain consistently associated with red meat consumption. Initial workup, including routine labs, imaging, and endoscopy, was unremarkable, but specific IgE testing confirmed AGS. Management included strict avoidance of red meat, carrying an epinephrine auto-injector, and referral to an allergist for education and long-term care. This case highlights the diagnostic challenges posed by the delayed reaction and the importance of dietary vigilance and emergency preparedness. Increased awareness of AGS is essential, especially in regions where tick exposure is prevalent.

Clinical Presentation and Outcomes of Alpha-Gal Syndrome

BACKGROUND AND AIMS

Alpha-gal syndrome (AGS) is an IgE-mediated allergic reaction to galactose-α-1,3-galactose, primarily linked with Lone Star tick bites in the United States. It presents with symptoms ranging from urticaria and gastrointestinal (GI) manifestations to delayed anaphylaxis following red meat consumption. We aimed to study AGS patients' clinical manifestations, diagnosis, and outcomes.

METHODS

A retrospective chart review of patients who underwent serological testing for suspected AGS between 2014 and 2023 at Mayo Clinic was performed. Patients with positive serology were age and sex matched with those who tested negative. Clinical characteristics of seropositive cohort with and without GI symptoms were compared, and outcomes assessed.

RESULTS

Of 1260 patients who underwent testing, 124 tested positive for AGS. They were matched with 380 seronegative control subjects. AGS patients reported a higher frequency of tick bites (odds ratio [OR], 26.0; 95% confidence interval [CI], 9.8-68.3), reported a higher prevalence of urticaria (56% vs 37%; P = .0008), and were less likely to have asthma (OR, 0.4; 95% CI, 0.3-0.7). They had a lower prevalence of heartburn (6% vs 12%; P = .03) and bloating (6% vs 13%; P = .03). A total of 47% had GI symptoms, and a higher proportion were female than those without GI symptoms (69% vs 35%; P = .002). During a mean follow-up of 27 months, 22 of 40 patients reported symptom resolution after avoiding red meat, and 7 were able to transition to regular diet.

CONCLUSIONS

A diagnosis of AGS should be strongly considered in patients with a history of tick bites and clinical presentation of allergic or GI manifestations. Dietary intervention is effective in most but not all patients.

Allergenic potency of various foods of mammalian origin in patients with α-Gal syndrome

BACKGROUND

The α-Gal syndrome (AGS) is an emerging allergy to mammalian food caused by IgE-mediated reactions to the carbohydrate galactose-α-1,3-galactose (α-Gal). Mammalian food sources contain α-Gal, but the amount differs. The objective of this study was to investigate the allergenic potency of various foods of mammalian origin among AGS patients.

METHODS

Twenty-six AGS patients were included. Food extracts from innards, lean meats, processed meat products, milk, and whey were analyzed. Immunoblot, ELISA, immunofluorescence, and basophil activation test were used to determine the α-Gal content, characterize IgE binding, and assess foods' allergenicity.

RESULTS

The determined amount of α-Gal, IgE reactivity to food extracts, and food extract potencies to activate patients' basophils correlated well with each other. Pork and beef kidney showed the highest allergenicity. Beef liver and bacon showed allergenicity comparable to that of lean meats. Game meat seemed to have a higher allergenic potency than meats from farm-raised animals. The processed meat products liver pâté and black pudding, despite lower α-Gal content, demonstrated moderate allergenicity. Milk showed the lowest allergenicity. IgE reactivity to food extracts was highly similar for all patients and strongly dominated by the α-Gal epitope.

CONCLUSIONS

The allergenic potency of mammalian meat depends on the origin of the meat, the different cuts, and type of processing, with innards posing the greatest risk to AGS patients. Even processed mammalian meat constitutes a risk. Dairy products show the lowest risk. This study highlights the importance of analyzing even more foods to improve the management of AGS.

Application of collagen in bone regeneration

At present, there is a significant population of individuals experiencing bone deficiencies caused by injuries, ailments affecting the bones, congenital abnormalities, and cancer. The management of substantial bone defects a significant global orthopedic challenge due to the intricacies involved in promoting and restoring the growth of fresh osseous tissue. Autografts are widely regarded as the "gold standard" for repairing bone defects because of their superior tissue acceptance and ability to control osteogenesis. However, patients undergoing autografts may encounter various challenges, including but not limited to hernia, bleeding, nerve impairment, tissue death. Therefore, researchers in regenerative medicine are striving to find alternatives. Collagen is the most abundant protein in the human body, and its triple helix structure gives it unique characteristics that contribute to its strength and functionality in various tissues. Collagen is commonly processed into various forms such as scaffolds, sponges, membranes, hydrogels, and composite materials, due to its unique compatibility with the human body, affinity for water, minimal potential for immune reactions, adaptability, and ability to transport nutrients or drugs. As an alternative material in the field of bone regeneration, collagen is becoming increasingly important. The objective of this review is to provide a comprehensive analysis of the primary types and sources of collagen, their processes of synthesis and degradation, as well as the advancements made in bone regeneration research and its potential applications. A comprehensive investigation into the role of collagen in bone regeneration is undertaken, providing valuable points of reference for a more profound comprehension of collagen applications in this field. The concluding section provides a comprehensive overview of the prospective avenues for collagen research, underscoring their promising future and highlighting their significant potential in the field of bone regeneration. The Translational Potential of this Article. The comprehensive exploration into the diverse functions and translational potential of collagen in bone regeneration, as demonstrated in this review, these findings underscore their promising potential as a treatment option with significant clinical implications, thus paving the way for innovative and efficacious therapeutic strategies in this domain.

Immunoglobulin E (IgE)-mediated food allergy

Food allergy is defined as an adverse immunologic response to a food. Immunoglobulin E (IgE)-mediated reactions to foods are associated with a broad range of signs and symptoms that may involve any of the following body systems: the skin, gastrointestinal tract, respiratory tract, and cardiovascular system. IgE-mediated food allergy is a leading cause of anaphylaxis. Therefore, timely and appropriate diagnosis and treatment are imperative. A diagnosis of food allergy entails a careful history and diagnostic tests, which may include skin prick tests, serum-specific IgE, and oral food challenge. The goal of food allergy care is to empower patients and caregivers to manage the risk of food-allergic reactions, reduce food allergy-related anxiety, and achieve a sense of control over their condition. This can be achieved in different ways for different patients and across different life stages. This article provides an overview of the epidemiology, pathophysiology, diagnosis, and management of IgE-mediated food allergy.

Biologics in allergology and clinical immunology: Update on therapies for atopic diseases, urticaria, and angioedema and on safety aspects focusing on hypersensitivity reactions

The development of targeted therapies for atopic diseases, urticaria, and angioedema with biologics is progressing rapidly: New "targets" of clinical-therapeutic relevance have been identified, the corresponding targeted antibodies developed, tested in clinical trials, and approved for therapy. These include the anti-IgE antibody omalizumab (also effective and approved for the treatment of urticaria), the anti-IL-4/13 receptor-specific antibody dupilumab, the two anti-IL-13 antibodies lebrikizumab and tralokinumab, the anti-TSLP antibody tezepelumab, the two anti-IL-5 antibodies mepolizumab and reslizumab, and the anti-IL5 receptor-specific antibody benralizumab for the treatment of atopic diseases. For the treatment of hereditary angioedema, C1 inhibitor and the antibody lanadelumab (directed against kallikrein) have also long been approved as biologics in addition to low-molecular substances. Other therapeutic antibodies are in various stages of development. Furthermore, the range of indications for some very effective biologics has been successfully expanded to include additional diseases. In this context, the first results on biologic therapy of food allergy and eosinophilic esophagitis are interesting. Biologics that address different target structures are also increasingly being administered in combination, either simultaneously or sequentially, in order to achieve optimal efficacy. A developing area is the use of biologics in children and the observation of immunological and non-immunological side effects. In some cases, new unexpected side effects and hypersensitivity reactions have emerged, which in turn raise pathomechanistic questions, such as conjunctivitis with dupilumab therapy, which only appears to occur in the treatment of atopic dermatitis but not in the treatment of other atopic diseases. In dermatology, paradoxical reactions have been described under therapy with some biologics. And immune reactions of type alpha to epsilon to biologics (hypersensitivity reactions) continue to be a clinically relevant problem, whereby the selection of an alternative therapeutic agent is a challenge and the diagnostics that support this have not yet been sufficiently incorporated into routine work.

The role of antibody glycosylation in autoimmune and alloimmune kidney diseases

Immunoglobulin glycosylation is a pivotal mechanism that drives the diversification of antibody functions. The composition of the IgG glycome is influenced by environmental factors, genetic traits and inflammatory contexts. Differential IgG glycosylation has been shown to intricately modulate IgG effector functions and has a role in the initiation and progression of various diseases. Analysis of IgG glycosylation is therefore a promising tool for predicting disease severity. Several autoimmune and alloimmune disorders, including critical and potentially life-threatening conditions such as systemic lupus erythematosus, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and antibody-mediated kidney graft rejection, are driven by immunoglobulin. In certain IgG-driven kidney diseases, including primary membranous nephropathy, IgA nephropathy and lupus nephritis, particular glycome characteristics can enhance in situ complement activation and the recruitment of innate immune cells, resulting in more severe kidney damage. Hypofucosylation, hypogalactosylation and hyposialylation are the most common IgG glycosylation traits identified in these diseases. Modulating IgG glycosylation could therefore be a promising therapeutic strategy for regulating the immune mechanisms that underlie IgG-driven kidney diseases and potentially reduce the burden of immunosuppressive drugs in affected patients.

Ixodes ricinus bites promote allergic skin inflammation and intestinal tuft and mast cell expansion in mice

Background

Tick bites often promote local allergic reactions in the skin and predispose to red meat allergy. The mechanisms involved in these processes are not fully understood. Here we investigated the local changes to the skin and intestine induced by tick bites.

Methods

C3H/HEN or Balb/c mice were subjected to either tick bites by Ixodes ricinus ( I. ricinus ) or mechanical skin injury. Skin or intestine was analyzed a different time point by transcriptomic and histological techniques.

Results

Our results indicate that I. ricinus bites promote epidermal hyperplasia, spongiosis and an accumulation of eosinophils and mast cells in the bitten skin. In addition, I. ricinus bites promote the expression of genes and activate pathways also induced by mechanical skin injury elicited by tape stripping. Remarkably, similar to tape stripping, I. ricinus bites promote an increase in total serum IgE, and intestinal tuft cell and mast cell expansion.

Conclusion

I. ricinus bites in mice promote cutaneous inflammation that resembles allergic skin inflammation, as well as intestinal changes that could play a role in the predisposition to red meat allergy.

Microbiological and chemical hazards in cultured meat and methods for their detection

Cultured meat, which involves growing meat in a laboratory rather than breeding animals, offers potential benefits in terms of sustainability, health, and animal welfare compared to conventional meat production. However, the cultured meat production process involves several stages, each with potential hazards requiring careful monitoring and control. Microbial contamination risks exist in the initial cell collection from source animals and the surrounding environment. During cell proliferation, hazards may include chemical residues from media components such as antibiotics and growth factors, as well as microbial issues from improper bioreactor sterilization. In the differentiation stage where cells become muscle tissue, potential hazards include residues from scaffolding materials, microcarriers, and media components. Final maturation and harvesting stages risk environmental contamination from nonsterile conditions, equipment, or worker handling if proper aseptic conditions are not maintained. This review examines the key microbiological and chemical hazards that must be monitored and controlled during the manufacturing process for cultured meats. It describes some conventional and emerging novel techniques that could be applied for the detection of microbial and chemical hazards in cultured meat. The review also outlines the current evolving regulatory landscape around cultured meat and explains how thorough detection and characterization of microbiological and chemical hazards through advanced analytical techniques can provide crucial data to help develop robust, evidence-based food safety regulations specifically tailored for the cultured meat industry. Implementing new digital food safety methods is recommended for further research on the sensitive and effective detection of microbiological and chemical hazards in cultured meat.

Tick bites, IgE to galactose-alpha-1,3-galactose and urticarial or anaphylactic reactions to mammalian meat: The alpha-gal syndrome

The recent recognition of a syndrome of tick-acquired mammalian meat allergy has transformed the previously held view that mammalian meat is an uncommon allergen. The syndrome, mediated by IgE antibodies against the oligosaccharide galactose-alpha-1,3-galactose (alpha-gal), can also involve reactions to visceral organs, dairy, gelatin and other products, including medications sourced from non-primate mammals. Thus, fittingly, this allergic disorder is now called the alpha-gal syndrome (AGS). The syndrome is strikingly regional, reflecting the important role of tick bites in sensitization, and is more common in demographic groups at risk of tick exposure. Reactions in AGS are delayed, often by 2-6 h after ingestion of mammalian meat. In addition to classic allergic symptomatology such as urticaria and anaphylaxis, AGS is increasingly recognized as a cause of isolated gastrointestinal morbidity and alpha-gal sensitization has also been linked with cardiovascular disease. The unusual link with tick bites may be explained by the fact that allergic cells and mediators are mobilized to the site of tick bites and play a role in resistance against ticks and tick-borne infections. IgE directed to alpha-gal is likely an incidental consequence of what is otherwise an adaptive immune strategy for host defense against endo- and ectoparasites, including ticks.

Molecular Allergology and Component-Resolved Diagnosis in Current Clinical Practice

Specific immunoglobulin E immunodiagnostics is becoming a convenient way to identify allergic patients and their specific allergies. These results are comparable to skin testing and may be more accessible for some populations. Each allergen contains thousands of molecules but only a few of these molecules are allergenic to humans. Each allergen has a number of individual components-generally proteins-which have different characteristics that may impact the effects of sensitization. Identification of the specific component allows for differentiation of the true allergies and can help to determine the risk of a significant clinical response.

A sustainable strategy for generating highly stable human skin equivalents based on fish collagen

Tissue engineered skin equivalents are increasingly recognized as potential alternatives to traditional skin models such as human ex vivo skin or animal skin models. However, most of the currently investigated human skin equivalents (HSEs) are constructed using mammalian collagen which can be expensive and difficult to extract. Fish skin is a waste product produced by fish processing industries and identified as a cost-efficient and sustainable source of type I collagen. In this work, we describe a method for generating highly stable HSEs based on fibrin fortified tilapia fish collagen. The fortified fish collagen (FFC) formulation is optimized to enable reproducible fabrication of full-thickness HSEs that undergo limited contraction, facilitating the incorporation of human donor-derived skin cells and formation of biomimetic dermal and epidermal layers. The morphology and barrier function of the FFC HSEs are compared with a commercial skin model and validated with immunohistochemical staining and transepithelial electrical resistance testing. Finally, the potential of a high throughput screening platform with FFC HSE is explored by scaling down its fabrication to 96-well format.

Serum antibody screening using glycan arrays

Humans and other animals produce a diverse collection of antibodies, many of which bind to carbohydrate chains, referred to as glycans. These anti-glycan antibodies are a critical part of our immune systems' defenses. Whether induced by vaccination or natural exposure to a pathogen, anti-glycan antibodies can provide protection against infections and cancers. Alternatively, when an immune response goes awry, antibodies that recognize self-glycans can mediate autoimmune diseases. In any case, serum anti-glycan antibodies provide a rich source of information about a patient's overall health, vaccination history, and disease status. Glycan microarrays provide a high-throughput platform to rapidly interrogate serum anti-glycan antibodies and identify new biomarkers for a variety of conditions. In addition, glycan microarrays enable detailed analysis of the immune system's response to vaccines and other treatments. Herein we review applications of glycan microarray technology for serum anti-glycan antibody profiling.

A survey of FDA Approved Monoclonal Antibodies and Fc-fusion Proteins for Manufacturing Changes and Comparability Assessment

OBJECTIVE

Manufacturing changes occur commonly throughout stages of biologics development and may result in product quality attribute changes. As changes in critical quality attributes have the potential to affect clinical safety and efficacy of products, it is imperative to ensure the quality and clinical performance before introducing the after-change products. Thus, we embarked on this project to understand what data have supported the manufacturing changes for licensed products with pre- and post-approval changes.

METHODS

We surveyed the manufacturing changes of 85 monoclonal antibodies and 10 Fc fusion proteins approved by the Food and Drug Administration as of December 25, 2021. After collecting the type and timing of changes for these products, we investigated the approaches that provided supporting data for the changes. The source documents included reports submitted by applicants and FDA's regulatory reviews.

RESULTS

Analytical comparability was assessed to support all identified manufacturing changes. Supporting clinical data were available in 92% of these manufacturing changes; including data from pharmacokinetic comparability studies alone (3%), other studies on efficacy or safety (70%) and a combination of both (19%). Clinical pharmacokinetic comparability data contributed to supporting substantial changes, such as host cell type or master cell bank changes, concentration or formulation changes, and changes from pre-filled syringes to autoinjectors, especially when introduced after completing pivotal studies.

CONCLUSION

Our comprehensive retrospective analysis provides an understanding of the regulatory experience and industry practice, which could facilitate developing appropriate comparability approaches to support manufacturing changes in the future.

The role of glycosylation in clinical allergy and immunology

While glycans are among the most abundant macromolecules on the cell with widespread functions, their role in immunity has historically been challenging to study. This is in part due to difficulties assimilating glycan analysis into routine approaches used to interrogate immune cell function. Despite this, recent developments have illuminated fundamental roles for glycans in host immunity. The growing field of glycoimmunology continues to leverage new tools and approaches to uncover the function of glycans and glycan-binding proteins in immunity. Here we utilize clinical vignettes to examine key roles of glycosylation in allergy, inborn errors of immunity, and autoimmunity. We will discuss the diverse functions of glycans as epitopes, as modulators of antibody function, and as regulators of immune cell function. Finally, we will highlight immune modulatory therapies that harness the critical role of glycans in the immune system.

Approach to Idiopathic Anaphylaxis in Adolescents

Anaphylaxis is a potentially-life threatening condition. Adolescents are particularly vulnerable due to increased risk-taking behaviors, poor disease management, and minimized perception of risk. Although most anaphylaxis can be attributed to food, drug, or venom allergy via a detailed history and confirmatory studies, in nearly 1 in 5 cases, the cause may not be obvious. Clinical differentials including rare allergens, cofactors, mast-cell disorders, and mimic disorders can increase the likelihood of discovering of the cause of anaphylaxis.

Multi-omics analysis of zebrafish response to tick saliva reveals biological processes associated with alpha-Gal syndrome

The alpha-Gal syndrome (AGS) is a tick-borne allergy. A multi-omics approach was used to determine the effect of tick saliva and mammalian meat consumption on zebrafish gut transcriptome and proteome. Bioinformatics analysis using R software was focused on significant biological and metabolic pathway changes associated with AGS. Ortholog mapping identified highly concordant human ortholog genes for the detection of disease-enriched pathways. Tick saliva treatment increased zebrafish mortality, incidence of hemorrhagic type allergic reactions and changes in behavior and feeding patterns. Transcriptomics analysis showed downregulation of biological and metabolic pathways correlated with anti-alpha-Gal IgE and allergic reactions to tick saliva affecting blood circulation, cardiac and vascular smooth muscle contraction, behavior and sensory perception. Disease enrichment analysis revealed downregulated orthologous genes associated with human disorders affecting nervous, musculoskeletal, and cardiovascular systems. Proteomics analysis revealed suppression of pathways associated with immune system production of reactive oxygen species and cardiac muscle contraction. Underrepresented proteins were mainly linked to nervous and metabolic human disorders. Multi-omics data revealed inhibition of pathways associated with adrenergic signaling in cardiomyocytes, and heart and muscle contraction. Results identify tick saliva-related biological pathways supporting multisystemic organ involvement and linking α-Gal sensitization with other illnesses for the identification of potential disease biomarkers.

Tick salivary glycans - a sugar-coated tick bite

Ticks are hematophagous arthropods that transmit disease-causing pathogens worldwide. Tick saliva deposited into the tick-bite site is composed of an array of immunomodulatory proteins that ensure successful feeding and pathogen transmission. These salivary proteins are often glycosylated, and glycosylation is potentially critical for the function of these proteins. Some salivary glycans are linked to the phenomenon of red meat allergy - an allergic response to red meat consumption in humans exposed to certain tick species. Tick salivary glycans are also invoked in the phenomenon of acquired tick resistance wherein non-natural host species exposed to tick bites develop an immune response that thwarts subsequent tick feeding. This review dwells on our current knowledge of these two phenomena, thematically linked by salivary glycans.

A conversation on allergy: recognizing the past and looking to the future

Allergy is an ever-evolving group of disorders, which includes asthma, atopic dermatitis, rhinitis and food allergies and that currently affects over 1 billion people worldwide. This group of disorders has exploded in incidence since around the start of the 20th century, implying that genetics is not solely responsible for its development but that environmental factors have an important role. Here, Fabio Luciani and Jonathan Coquet, in their role as editors at Immunology & Cell Biology, asked nine prominent researchers in the field of allergy to define the term 'allergy', discuss the role of genetics and the environment, nominate the most important discoveries of the past decade and describe the best strategies to combat allergy at the population level going forward.

Mechanistic insights into the interaction between the host gut microbiome and malaria

Malaria is a devastating infectious disease and significant global health burden caused by the bite of a Plasmodium-infected female Anopheles mosquito. Gut microbiota was recently discovered as a risk factor of severe malaria. This review entails the recent advances on the impact of gut microbiota composition on malaria severity and consequence of malaria infection on gut microbiota in mammalian hosts. Additionally, this review provides mechanistic insight into interactions that might occur between gut microbiota and host immunity which in turn can modulate malaria severity. Finally, approaches to modulate gut microbiota composition are discussed. We anticipate this review will facilitate novel hypotheses to move the malaria-gut microbiome field forward.

Emerging Hyalomma lusitanicum: From identification to vectorial role and integrated control

In the Mediterranean basin, the tick species Hyalomma lusitanicum Koch stands out among other species of the Hyalomma genus due to its wide distribution, and there is great concern about its potential role as a vector and/or reservoir and its continuous expansion to new areas because of climate warming and human and other animal movements. This review aims to consolidate all the information on H. lusitanicum, including taxonomy and evolution, morphological and molecular identification, life cycle, sampling methods, rearing under laboratory conditions, ecology, hosts, geographical distribution, seasonality, vector role and control methods. The availability of adequate data is extremely relevant to the development of appropriate control strategies in areas where this tick is currently distributed as well as in new areas where it could become established in the near future.

Delayed Hypersensitivity Reaction to Infliximab Due to Mammalian Meat Allergy

Mammalian meat allergy is a delayed immunoglobulin E (IgE) mediated hypersensitivity reaction to galactose-alpha-1,3-galactose (alpha-gal). Alpha-gal is an oligosaccharide present on glycoproteins and glycolipids of nonprimate mammals as well as biologic agents prepared using mammalian cells including infliximab. We describe a pediatric patient with Crohn's disease who developed urticaria and pruritus roughly 6 hours after her very first infliximab infusion that progressed to chronic urticaria following subsequent infliximab infusions. She was diagnosed with mammalian meat allergy based on an elevated serum IgE level directed against alpha-gal. Her symptoms resolved once infliximab infusions were discontinued and did not recur after commencing therapy with adalimumab.

Overview of Allergy and Anaphylaxis

Allergic reactions and anaphylaxis occur on a severity continuum from mild and self-limited to potentially life-threatening or fatal reactions. Anaphylaxis is typically a multiorgan phenomenon involving a broad range of effector cells and mediators. Emergency department visits for anaphylaxis are increasing, especially among children. There is a broad differential diagnosis for anaphylaxis, and the diagnosis of anaphylaxis can be aided by the use of the National Institutes of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network clinical diagnostic criteria. Risk factors for severe anaphylaxis include older age, delayed epinephrine administration, and cardiopulmonary comorbidities.

Extrinsic and Intrinsic Modulators of Anaphylaxis

The severity of anaphylaxis is determined by many factors. The allergenic source as well as the age of the affected individual and the route of allergen exposure encompass the major contributors of the clinical outcome. Moreover, the severity can be modulated further by intrinsic and extrinsic factors. Among these, the genetic predisposition, certain comorbidities such as uncontrolled asthma, and hormonal fluctuations have been proposed as intrinsic and antihypertensive medications or physical activity as extrinsic factors. Recent advances have highlighted immunologic pathways that may exacerbate the response to allergens through receptors on mast cells, basophils, platelets, and other granulocytes. Atopy, platelet-activating factor acetylhydrolase deficiency, hereditary alpha tryptasemia, and clonal mast cell disorders are examples associated with genetic alterations that may predispose to severe anaphylaxis. Identifying risk factors that lower the threshold of reactivity or increase the severity of multisystem reactions is important in the management of this patient population.

Alpha-gal Syndrome - A Case Report of Tick-Borne Anaphylactic Shock

The most common cause of vasoplegic shock in critical care is sepsis. However, although rarely and only in specifically sensitised individuals previously bitten by a tick, red meat may provoke a delayed allergic reaction called an alpha-gal syndrome. We present a case of a protracted life-threatening manifestation of alpha-gal syndrome, which, due to an unusual absence of typical features of anaphylaxis can masquerade as septic shock and calls attention to the premature diagnostic closure as a contributor to diagnostic error. Alpha-gal syndrome is a relatively new, but increasingly recognised health issue. We propose that alpha-gal syndrome should be considered in the differential diagnosis of vasoplegic shock of unclear aetiology even in the absence of typical allergic symptomatology and typical allergen exposure since alpha-gal is present in a wide variety of carriers.

LEARNING POINTS

Alpha-gal syndrome, otherwise known as "red meat allergy", is a potentially life-threatening allergic syndrome induced by the immunological properties of tick saliva.A typical case of alpha-gal syndrome is a patient bitten by a tick who develops an allergic reaction, anaphylaxis or anaphylactic shock even after an ingestion of a significant amount of alpha-gal, typically present in red mammalian meat or organs.As global warming continues, we may expect tick-borne diseases to spread wider around the globe and due to the possibility of complete absence of typical allergic symptomatology and the delayed onset of symptoms, this syndrome needs to be considered when encountering vasoplegic shock of uncertain origin.

Identification, Baculoviral Expression, and Biochemical Characterization of a Novel Cholinesterase of Amblyomma americanum (Acari: Ixodidae)

A cDNA encoding a novel cholinesterase (ChE, EC 3.1.1.8) from the larvae of Amblyomma americanum (Linnaeus) was identified, sequenced, and expressed in Sf21 insect cell culture using the baculoviral expression vector pBlueBac4.5/V5-His. The open reading frame (1746 nucleotides) of the cDNA encoded 581 amino acids beginning with the initiation codon. Identical cDNA sequences were amplified from the total RNA of adult tick synganglion and salivary gland, strongly suggesting expression in both tick synganglion and saliva. The recombinant enzyme (rAaChE1) was highly sensitive to eserine and BW284c51, relatively insensitive to tetraisopropyl pyrophosphoramide (iso-OMPA) and ethopropazine, and hydrolyzed butyrylthiocholine (BuTCh) 5.7 times as fast as acetylthiocholine (ATCh) at 120 µM, with calculated K_M values for acetylthiocholine (ATCh) and butyrylthiocholine of 6.39 µM and 14.18 µM, respectively. The recombinant enzyme was highly sensitive to inhibition by malaoxon, paraoxon, and coroxon in either substrate. Western blots using polyclonal rabbit antibody produced by immunization with a peptide specific for rAaChE1 exhibited reactivity in salivary and synganglial extract blots, indicating the presence of AaChE1 antigenic protein. Total cholinesterase activities of synganglial or salivary gland extracts from adult ticks exhibited biochemical properties very different from the expressed rAaACh1 enzyme, evidencing the substantial presence of additional cholinesterase activities in tick synganglion and saliva. The biological function of AaChE1 remains to be elucidated, but its presence in tick saliva is suggestive of functions in hydrolysis of cholinergic substrates present in the large blood mean and potential involvement in the modulation of host immune responses to tick feeding and introduced pathogens.

Enhancing pharmacokinetic and pharmacodynamic properties of recombinant therapeutic proteins by manipulation of sialic acid content

The circulatory half-life of recombinant therapeutic proteins is an important pharmacokinetic attribute because it determines the dosing frequency of these drugs, translating directly to treatment cost. Thus, recombinant therapeutic glycoproteins such as monoclonal antibodies have been chemically modified by various means to enhance their circulatory half-life. One approach is to manipulate the N-glycan composition of these agents. Among the many glycan constituents, sialic acid (specifically, N-acetylneuraminic acid) plays a critical role in extending circulatory half-life by masking the terminal galactose that would otherwise be recognised by the hepatic asialoglycoprotein receptor (ASGPR), resulting in clearance of the biotherapeutic from the circulation. This review aims to provide an illustrative overview of various strategies to enhance the pharmacokinetic/pharmacodynamic properties of recombinant therapeutic proteins through manipulation of their sialic acid content.

Innovative Metrics for Reporting and Comparing the Glycan Structural Profile in Biotherapeutics

Glycosylation is a critical quality attribute in biotherapeutics, impacting properties such as protein stability, solubility, clearance rate, efficacy, immunogenicity, and safety. Due to the heterogenic and complex nature of protein glycosylation, comprehensive characterization is demanding. Moreover, the lack of standardized metrics for evaluating and comparing glycosylation profiles hinders comparability studies and the establishment of manufacturing control strategies. To address both challenges, we propose a standardized approach based on novel metrics for a comprehensive glycosylation fingerprint which greatly facilitates the reporting and objective comparison of glycosylation profiles. The analytical workflow is based on a liquid chromatography-mass spectrometry-based multi-attribute method. Based on the analytical data, a matrix of glycosylation-related quality attributes, both at site-specific and whole molecule level, are computed, which provide metrics for a comprehensive product glycosylation fingerprint. Two case studies illustrate the applicability of the proposed indices as a standardized and versatile approach for reporting all dimensions of the glycosylation profile. The proposed approach further facilitates the assessments of risks associated with changes in the glycosylation profile that may affect efficacy, clearance, and immunogenicity.

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Alpha-gal syndrome (AGS) in a glaucoma suspect with narrow iridocorneal angles

Purpose

Alpha-gal syndrome (AGS) is an allergy to non-primate mammalian carbohydrate (galactose-alpha-1,3-galactose) which may cause anaphylaxis. Allergic patients must avoid ophthalmic drugs containing animal-derived ingredients.

Observations

We report a 59-year-old non-Hispanic white woman who was referred for a glaucoma evaluation. She had been diagnosed with AGS after a tick bite in 2017. Ophthalmic exam revealed potentially occludable, narrow iridocorneal angles and laser iridotomy was recommended. Prior to performing the iridotomy, we investigated the ophthalmic medications required for the procedure to identify options that are free of animal-derived products and safe to use. Laser iridotomy was performed without complications or allergy to medications.

Conclusions

Ophthalmologists need to be aware of both the presence of AGS as well as the identity of ophthalmic medications that are safe to use in patients with this condition to avoid potentially lethal allergic responses.

Simplifying the detection and monitoring of protein glycosylation during in vitro glycoengineering

The majority of mammalian proteins are glycosylated, with the glycans serving to modulate a wide range of biological activities. Variations in protein glycosylation can have dramatic effects on protein stability, immunogenicity, antibody effector function, pharmacological safety and potency, as well as serum half-life. The glycosylation of therapeutic biologicals is a critical quality attribute (CQA) that must be carefully monitored to ensure batch-to-batch consistency. Notably, many factors can affect the composition of the glycans during glycoprotein production, and variations in glycosylation are among the leading causes of pharmaceutical batch rejection. Currently, the characterization of protein glycosylation relies heavily on methods that employ chromatography and/or mass spectrometry, which require a high level of expertise, are time-consuming and costly and, because they are challenging to implement during in-process biologics production or during in vitro glycan modification, are generally performed only post-production. Here we report a simplified approach to assist in monitoring glycosylation features during glycoprotein engineering, that employs flow cytometry using fluorescent microspheres chemically coupled to high-specificity glycan binding reagents. In our GlycoSense method, a range of carbohydrate-sensing microspheres with distinct optical properties may be combined into a multiplex suspension array capable of detecting multiple orthogonal glycosylation features simultaneously, using commonplace instrumentation, without the need for glycan release. The GlycoSense method is not intended to replace more detailed post-production glycan profiling, but instead, to complement them by potentially providing a cost-effective, rapid, yet robust method for use at-line as a process analytic technology (PAT) in a biopharmaceutical workflow or at the research bench. The growing interest in using in vitro glycoengineering to generate glycoproteins with well-defined glycosylation, provides motivation to demonstrate the capabilities of the GlycoSense method, which we apply here to monitor changes in the protein glycosylation pattern (GlycoPrint) during the in vitro enzymatic modification of the glycans in model glycoproteins.

Alpha-gal syndrome initially misdiagnosed as chronic spontaneous urticaria in a pediatric patient: a case report and review of the literature

INTRODUCTION

Delayed allergy to red meat, also termed alpha-gal syndrome, is increasingly reported in adults and African communities, while pediatric cases remain rare.

CASE PRESENTATION

Here, we report on a 7-year-old Caucasian boy presenting with recurrent wheals since the age of 5 years old. Episodes with hives occurred around every 3 weeks, mainly in the evening. One of these episodes was also associated with angioedema. No clear trigger was identified. At the first visit, after excluding an infection and autoimmune thyroiditis, chronic spontaneous urticaria was suspected and symptomatic treatment with antihistamines was prescribed. Six months later, the boy presented at the emergency room with generalized urticaria, dyspnoea, and emesis. Symptoms resolved after administration of epinephrine and antihistamines. A detailed medical history after this event revealed that he had eaten three sausages as well as jelly beans containing gelatine several hours prior to this episode. More precisely, after eating the sausages and jelly beans during the day, he had shown some hives before going to bed, and later developed the other symptoms in the middle of the night, suggesting alpha-gal syndrome. In his history, several tick bites are reported. Immunoglobulin E levels for alpha-gal were clearly elevated, confirming the diagnosis of a delayed-appearing immunoglobulin E-mediated allergic reaction to alpha-gal. Emergency medication was prescribed and avoidance of red meat and gelatine-containing foods was recommended. Under this exclusion diet, the boy remained asymptomatic, with the exception of two accidents in the follow up of 3 years, one developing during a barbecue and the second after exceptionally eating marshmallows.

CONCLUSION

A detailed clinical history led to the diagnosis of alpha-gal syndrome. Although alpha-gal syndrome is typically seen in adults, our case illustrates that children can also present with this potentially life-threatening allergy. Since alpha-gal syndrome is rare in Europe, the disease is not well known and often overlooked for several years, especially in children.

Perioperative Anaphylaxis

Anesthesiologists routinely manage patients receiving drugs and agents, all of which have the potential for anaphylaxis, the life-threatening presentation of an allergic reaction. Clinicians must be ready to diagnose and manage the acute cardiopulmonary dysfunction that occurs.

Systematic evaluation of three porcine-derived collagen membranes for guided bone regeneration

Guided bone regeneration is one of the most common surgical treatment modalities performed when an additional alveolar bone is required to stabilize dental implants in partially and fully edentulous patients. The addition of a barrier membrane prevents non-osteogenic tissue invasion into the bone cavity, which is key to the success of guided bone regeneration. Barrier membranes can be broadly classified as non-resorbable or resorbable. In contrast to non-resorbable membranes, resorbable barrier membranes do not require a second surgical procedure for membrane removal. Commercially available resorbable barrier membranes are either synthetically manufactured or derived from xenogeneic collagen. Although collagen barrier membranes have become increasingly popular amongst clinicians, largely due to their superior handling qualities compared to other commercially available barrier membranes, there have been no studies to date that have compared commercially available porcine-derived collagen membranes with respect to surface topography, collagen fibril structure, physical barrier property, and immunogenic composition. This study evaluated three commercially available non-crosslinked porcine-derived collagen membranes (Striate+^TM, Bio-Gide^® and Creos^TM Xenoprotect). Scanning electron microscopy revealed similar collagen fibril distribution on both the rough and smooth sides of the membranes as well as the similar diameters of collagen fibrils. However, D-periodicity of the fibrillar collagen is significantly different among the membranes, with Striate+^TM membrane having the closest D-periodicity to native collagen I. This suggests that there is less deformation of collagen during manufacturing process. All collagen membranes showed superior barrier property evidenced by blocking 0.2-16.4 μm beads passing through the membranes. To examine the immunogenic agents in these membranes, we examined the membranes for the presence of DNA and alpha-gal by immunohistochemistry. No alpha-gal or DNA was detected in any membranes. However, using a more sensitive detection method (real-time polymerase chain reaction), a relatively strong DNA signal was detected in Bio-Gide^® membrane, but not Striate+^TM and Creos^TM Xenoprotect membranes. Our study concluded that these membranes are similar but not identical, probably due to the different ages and sources of porcine tissues, as well as different manufacturing processes. We recommend further studies to understand the clinical implications of these findings.

Alpha-Gal Syndrome in the Infectious Diseases Clinic: A Series of 5 Cases in Central North Carolina

Background

Alpha-gal syndrome (AGS) is a recently described allergy to galactose-α-1,3-galactose, an oligosaccharide present in mammalian meat. AGS can present with angioedema, urticaria, and anaphylaxis arising 3-6 hours after ingestion, although symptoms such as gastrointestinal distress, fatigue, and arthralgias are also reported. Because AGS appears to be associated with tick bites, patients may present to infectious diseases (ID) clinics for evaluation.

Methods

We documented a series of 5 patients referred to the University of North Carolina ID Clinic between 2020 and 2022 for various tick-borne infections that were found to have symptoms and laboratory testing consistent with AGS. Patients were subsequently referred to the Allergy and Immunology Clinic.

Results

Patients were referred to the ID Clinic for persistent symptoms following positive tick-borne disease testing or presumed tick-borne infection. All patients had an elevated alpha-gal immunoglobulin E and clinical presentation consistent with AGS. Common symptoms included episodic gastrointestinal distress (eg, cramping, nausea, diarrhea), fatigue, arthralgias, and subjective cognitive impairment, but a notable absence of severe anaphylaxis. Four patients were seen by at least 1 nonallergy specialist prior to referral to ID. Patients reported substantial improvement in their symptoms following dietary restriction.

Conclusions

ID physicians should be aware of AGS as a cause of persistent, nonspecific symptoms following a tick exposure or tick-borne illness. Further research is needed to determine the prevalence of alpha-gal sensitization and AGS following tick-borne bites.

Incidence and associated factors of cetuximab-induced hypersensitivity infusion reactions in 1392 cancer patients treated in four French areas: a possible association with Lyme disease?

BACKGROUND

Previous studies have observed an increased incidence of Cetuximab-induced hypersensitivity infusion reactions (CI-IRs) in the southeastern states of the USA. Tick's bites were suspected of generating cross-reactions between cetuximab and alpha-gal. This study aims was to describe the incidence and associated risk factors of CI-IRs, in the French areas chosen according to their Lyme disease incidence.

PATIENTS AND METHODS

A retrospective chart review was conducted on patients that received cetuximab infusion from January 2010 to June 2019 in 4 French areas with different Lyme disease incidence rates.

RESULTS

Of 1392 patients, 117 (8.4%) experienced a CI-IR, including 68 severe (grade 3 or 4) reactions (4.9%). This CI-IR incidence was significantly higher in the Lyme disease high-risk area than in the other areas (13.2% versus 7.1%, 8.1% and 6.4%; P = 0.016). Sex (P = 0.53), premedication (P = 0.91), primary cancer location (P = 0.46) and chemotherapy regimen type (P = 0.78) had no impact on CI-IR incidence in the overall population. In the head and neck squamous cell carcinoma (HNSCC) patient subgroup, CI-IRs were significantly more frequent in the high-risk area (16.4% versus 6.7%, 7.1% and 7.0%; P = 0.0015).

CONCLUSION

This study suggests that patients treated in the French area with the highest incidence of Lyme disease are at a higher risk of CI-IRs.

Tick Species Composition, Collection Rates, and Phenology Provide Insights into Tick-Borne Disease Ecology in Virginia

To better understand tick ecology in Virginia and the increasing Lyme disease incidence in western Virginia, a comparative phenological study was conducted in which monthly collections were performed at twelve sampling locations in southwestern Virginia (high Lyme disease incidence) and 18 equivalent sampling locations in southeastern Virginia (low Lyme disease incidence) for one year. In western Virginia, we also explored the effect of elevation on collection rates of Ixodes scapularis Say (Acari: Ixodidae) and Amblyomma americanum (L.) (Acari: Ixodidae). In total, 35,438 ticks were collected (33,106 A. americanum; 2,052 I. scapularis; 134 Ixodes affinis Neumann [Acari: Ixodidae]; 84 Dermacentor variabilis [Say] [Acari: Ixodidae]; 49 Dermacentor albipictus [Packard] [Acari: Ixodidae]; 10 Haemaphysalis leporispalustris [Packard] [Acari: Ixodidae]; 2 Ixodes brunneus Koch [Acari: Ixodidae]; 1 Haemaphysalis longicornis Neumann [Acari: Ixodidae]). Within southwestern Virginia, Ixodes scapularis collection rates were not influenced by elevation, unlike A. americanum which were collected more frequently at lower elevations (e.g., below 500 m). Notably, I. scapularis larvae and nymphs were commonly collected in southwestern Virginia (indicating that they were questing on or above the leaf litter) but not in southeastern Virginia. Questing on or above the leaf litter is primarily associated with northern populations of I. scapularis. These findings may support the hypothesis that I. scapularis from the northeastern United States are migrating into western Virginia and contributing to the higher incidence of Lyme disease in this region. This comparative phenological study underscores the value of these types of studies and the need for additional research to further understand the rapidly changing tick-borne disease dynamics in Virginia.

A 67-Year-Old Man with Pruritus and Dyspnea

A 67-Year-Old Man with Pruritus and DyspneaThis report tells the story of a 67-year-old man presenting with itching on his back and shortness of breath. Recently diagnosed with metastatic tonsillar squamous cell carcinoma, he came to the oncology clinic to receive a chemotherapy infusion. Using questions, physical examination, and testing, an illness script for the presentation emerges; the differential is refined until a final diagnosis is made.

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.