Sensitization to Cannabis sativa caused by a novel allergenic lipid transfer protein, Can s 3

Concerns Related to the Consequences of Pediatric Cannabis Use: A 360-Degree View

Cannabis, a plant known for its recreational use, has gained global attention due to its widespread use and addiction potential. Derived from the Cannabis sativa plant, it contains a rich array of phytochemicals concentrated in resin-rich trichomes. The main cannabinoids, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), interact with CB1 and CB2 receptors, influencing various physiological processes. Particularly concerning is its prevalence among adolescents, often driven by the need for social connection and anxiety alleviation. This paper provides a comprehensive overview of cannabis use, its effects, and potential health risks, especially in adolescent consumption. It covers short-term and long-term effects on different body systems and mental health and highlights the need for informed decision making and public health initiatives, particularly regarding adolescent cannabis use.

Epicutaneous Sensitization to the Phytocannabinoid β-Caryophyllene Induces Pruritic Inflammation

In recent years, there has been increased accessibility to cannabis for recreational and medicinal use. Incidentally, there has been an increase in reports describing allergic reactions to cannabis including exacerbation of underlying asthma. Recently, multiple protein allergens were discovered in cannabis, yet these fail to explain allergic sensitization in many patients, particularly urticaria and angioedema. Cannabis has a rich chemical profile including cannabinoids and terpenes that possess immunomodulatory potential. We examined whether major cannabinoids of cannabis such as cannabidiol (CBD) and the bicyclic sesquiterpene beta-caryophyllene (β-CP) act as contact sensitizers. The repeated topical application of mice skin with β-CP at 10 mg/mL (50 µL) induced an itch response and dermatitis at 2 weeks in mice, which were sustained for the period of study. Histopathological analysis of skin tissues revealed significant edema and desquamation for β-CP at 10 mg/mL. For CBD and β-CP, we observed a dose-dependent increase in epidermal thickening with profound thickening observed for β-CP at 10 mg/mL. Significant trafficking of CD11b cells was observed in various compartments of the skin in response to treatment with β-CP in a concentration-dependent manner. Mast cell trafficking was restricted to β-CP (10 mg/mL). Mouse proteome profiler cytokine/chemokine array revealed upregulation of complement C5/5a (anaphylatoxin), soluble intracellular adhesion molecule-1 (sICAM-1) and IL-1 receptor antagonist (IL-1RA) in animals dosed with β-CP (10 mg/mL). Moreover, we observed a dose-dependent increase in serum IgE in animals dosed with β-CP. Treatment with β-CP (10 mg/mL) significantly reduced filaggrin expression, an indicator of barrier disruption. In contrast, treatment with CBD at all concentrations failed to evoke scratching and dermatitis in mice and did not result in increased serum IgE. Further, skin tissues were devoid of any remarkable features, although at 10 mg/mL CBD we did observe the accumulation of dermal CD11b cells in skin tissue sections. We also observed increased filaggrin staining in mice repeatedly dosed with CBD (10 mg/mL). Collectively, our studies indicate that repeated exposure to high concentrations of β-CP can induce dermatitis-like pathological outcomes in mice.

Proteomics-Based Approach for Detailing the Allergenic Profile of Cannabis Chemotypes

Allergic sensitization to cannabis is an emerging public health concern and is difficult to clinically establish owing to lack of standardized diagnostic approaches. Attempts to develop diagnostic tools were largely hampered by the Schedule I restrictions on cannabis, which limited accessibility for research. Recently, however, hemp was removed from the classified list, and increased accessibility to hemp allows for the evaluation of its practical clinical value for allergy diagnosis. We hypothesized that the proteomic profile is preserved across different cannabis chemotypes and that hemp would be an ideal source of plant material for clinical testing. Using a proteomics-based approach, we examined whether distinct varieties of cannabis plant contain relevant allergens of cannabis. Cannabis extracts were generated from high tetrahydrocannabinol variety (Mx), high cannabidiol variety (V1-19) and mixed profile variety (B5) using a Plant Total Protein Extraction Kit. Hemp extracts were generated using other standardized methods. Protein samples were subjected to nanoscale tandem mass spectrometry. Acquired peptides sequences were examined against the Cannabis sativa database to establish protein identity. Non-specific lipid transfer protein (Can s 3) level was measured using a recently developed ELISA 2.0 assay. Proteomic analysis identified 49 distinct potential allergens in protein extracts from all chemotypes. Most importantly, clinically relevant and validated allergens, such as profilin (Can s 2), Can s 3 and Bet v 1-domain-containing protein 10 (Can s 5), were identified in all chemotypes at label-free quantification (LFP) intensities > 106. However, the oxygen evolving enhancer protein 2 (Can s 4) was not detected in any of the protein samples. Similarly, Can s 2, Can s 3 and Can s 5 peptides were also detected in hemp protein extracts. The validation of these findings using the ELISA 2.0 assay indicated that hemp extract contains 30-37 ng of Can s 3 allergen per µg of total protein. Our proteomic studies indicate that relevant cannabis allergens are consistently expressed across distinct cannabis chemotypes. Further, hemp may serve as an ideal practical substitute for clinical testing, since it expresses most allergens relevant to cannabis sensitization, including the validated major allergen Can s 3.

Hemp seed: An allergen source with potential cross-reactivity to hazelnut

The increasing exposure of the population to Cannabis sativa has revealed allergies to different parts of the plant, among which hemp seed. Nonetheless, the major hemp seed allergens remain to be identified. Several known families of allergens are present in hemp seed, including notably seed storage proteins. We therefore aimed to investigate the potential allergenicity of the hemp seed storage proteins and their potential cross-reactivity to different seeds and nuts. For this, we extracted hemp seed proteins sequentially using buffers with increasing levels of salinity (H₂O, T2 and T3) to yield extracts differentially enriched in storage proteins. We used these extracts to perform immunoblots and ELISAs using sera of patients either sensitized to hemp seeds or sensitized/allergic to other seeds and nuts. Immunoblots and proteomics analyses identified vicilins and edestins as potential hemp seed allergens. Moreover, ELISA analyses revealed a correlation between sensitization to hazelnut and the hemp seed T3 extract (enriched in storage proteins). The possible cross-reactivity between hazelnut and hemp seed proteins was further strengthened by the results from inhibition ELISAs: the incubation of sera from hazelnut-sensitized individuals with increasing concentrations of the T3 extract inhibited serum IgE binding to the hazelnut extract by about 25-30%. Our study thus identifies vicilins and edestins as potential hemp seed allergens and highlights a possible cross-reactivity with hazelnut. The clinical relevance of this cross-reactivity between hemp seed and hazelnut needs to be further investigated in hazelnut-allergic individuals.

A review of cannabis allergy in the early days of legalization

Cannabis allergy is a burgeoning field; consequently, research is still in its infancy and allergists' knowledge surrounding this topic is limited. As cannabis legalization expands across the world, it is anticipated that there will be an increase in cannabis use. Thus, we hypothesize that a concomitant rise in the incidence of allergy to this plant can be expected. Initiatives aimed at properly educating health care professionals are therefore necessary. This review presents the most up-to-date information on a broad range of topics related to cannabis allergy. Although the clinical features of cannabis allergy are becoming more well described and recognized, the tools available to make a correct diagnosis are meager and often poorly accessible. In addition, research on cannabis allergy is still taking its first steps, and new and potentially groundbreaking findings in this field are expected to occur in the next few years. Finally, although therapeutic approaches are being developed, patient and physician education regarding cannabis allergy is certainly needed.

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.

Establishing diagnostic strategies for cannabis allergy

INTRODUCTION

Cannabis is the most widely consumed illicit drug in the world and carries a risk of severe IgE-mediated allergic reactions, requiring appropriate diagnostic management. Currently available diagnostics are still relatively limited and require careful interpretation of results to avoid harmful over- and underdiagnosis.

AREAS COVERED

This review focuses on the most up-to-date understandings of cannabis allergy diagnosis, starting with the main clinical features of the disease and the allergenic characteristics of Cannabis sativa, and then providing insights into in vivo, in vitro, and ex vivo diagnostic tests.

EXPERT OPINION

At present, the diagnosis of IgE-mediated cannabis allergy is based on a three-step approach that starts with accurate history taking and ends with a confirmation of sensitization to the whole extract and, finally, molecular components. Although much has been discovered since its first description in 1971, the diagnosis of cannabis allergy still has many unmet needs. The lack of commercial standardized and validated extracts and in vitro assays makes a harmonized workup of cannabis allergy difficult. Furthermore, the epidemiological characteristics, and clinical implications of sensitization to different molecular components are not yet fully known. Future research will complete the picture and likely result in an individualized and standardized approach.

Cannabis-related allergies: An international overview and consensus recommendations

Cannabis is the most widely used recreational drug in the world. Cannabis sativa and Cannabis indica have been selectively bred to develop their psychoactive properties. The increasing use in many countries has been accelerated by the COVID-19 pandemic. Cannabis can provoke both type 1 and type 4 allergic reactions. Officially recognized allergens include a pathogenesis-related class 10 allergen, profilin, and a nonspecific lipid transfer protein. Other allergens may also be relevant, and recognition of allergens may vary between countries and continents. Cannabis also has the potential to provoke allergic cross-reactions to plant foods. Since cannabis is an illegal substance in many countries, research has been hampered, leading to challenges in diagnosis since no commercial extracts are available for testing. Even in countries such as Canada, where cannabis is legalized, diagnosis may rely solely on the purchase of cannabis for prick-to-prick skin tests. Management consists of avoidance, with legal issues hindering the development of other treatments such as immunotherapy. Education of healthcare professionals is similarly lacking. This review aimed to summarize the current status of cannabis allergy and proposes recommendations for the future management of this global issue.

Surveillance of work-related asthma including the emergence of a cannabis-associated case series in Washington State

OBJECTIVE

We conducted surveillance for work-related asthma (WRA) in Washington State to identify the industry sectors and asthma exposures most commonly affecting injured workers and in need of prevention activities.

METHODS

Using workers' compensation data as the primary data source, valid cases were classified as work-aggravated asthma (WAA) or new onset asthma that includes occupational asthma (OA) and reactive airways dysfunction syndrome (RADS). The source of exposure that caused the worker's asthma, their industry and occupation were determined.

RESULTS

There were 784 valid work-related asthma cases identified for the period 2009-2016, WAA (n = 529) was most common followed by occupational asthma (n = 127) and RADS (n = 12). The Health Care and Social Assistance industry had the highest number of cases (n = 170) with 82% classified as WAA. The highest overall proportions of new onset asthma are occurring in Agriculture, Forestry, Fishing and Hunting (33% of work related asthma cases), Manufacturing (31%) and Construction (30%). The leading substances associated with new onset asthma across all industries include hop plant dust, wood and cedar dust, mineral and inorganic dust, mold, and cleaning materials. We describe ten cases of cannabis-associated asthma including seven from workers in the legalized cannabis industry, four of whom had OA.

CONCLUSION

State-based work-related asthma surveillance is critical in identifying the workers and exposures associated with this occupational disease, including the detection of a case-series in the cannabis industry.

Adverse Reactions to Illicit Drugs (Marijuana, Opioids, Cocaine) and Alcohol

Drug allergy has been a research topic within the allergy field for decades. However, many drug reactions presumed to be of allergic nature are not and originate from different mechanisms. Drug-induced reactions can affect numerous organ systems, present with various symptoms, and have more than 1 mechanism of action. In this rostrum article, we want to give an overview of the different allergic and nonallergic reactions that can be expected with the (illicit) use of cannabis, cocaine, opioids, and alcohol. In addition, this article focuses on the different methods available to diagnose allergy related to these 4 drug types and highlight the pitfalls of nonallergic reactions or allergy "mimickers" complicating the diagnosis of true drug allergy. Finally, the impact on current medical practices and future research in support of the allergist in diagnosis and treatment of these medical problems is addressed.

Non-specific lipid-transfer proteins: Allergen structure and function, cross-reactivity, sensitization, and epidemiology

Background

Discovered and described 40 years ago, non‐specific lipid transfer proteins (nsLTP) are present in many plant species and play an important role protecting plants from stressors such as heat or drought. In the last 20 years, sensitization to nsLTP and consequent reactions to plant foods has become an increasing concern.

Aim

The aim of this paper is to review the evidence for the structure and function of nsLTP allergens, and cross‐reactivity, sensitization, and epidemiology of nsLTP allergy.

Materials and Methods

A Task Force, supported by the European Academy of Allergy & Clinical Immunology (EAACI), reviewed current evidence and provide a signpost for future research. The search terms for this paper were “Non‐specific Lipid Transfer Proteins”, “LTP syndrome”, “Pru p 3”, “plant food allergy”, “pollen‐food syndrome”.

Results

Most nsLTP allergens have a highly conserved structure stabilised by 4‐disulphide bridges. Studies on the peach nsLTP, Pru p 3, demonstrate that nsLTPs are very cross‐reactive, with the four major IgE epitopes of Pru p 3 being shared by nsLTP from other botanically related fruits. These nsLTP allergens are to varying degrees resistant to heat and digestion, and sensitization may occur through the oral, inhaled or cutaneous routes. In some populations, Pru p 3 is the primary and sole sensitizing allergen, but many are poly‐sensitised both to botanically un‐related nsLTP in foods, and non‐food sources of nsLTP such as Cannabis sativa, Platanus acerifolia, (plane tree), Ambrosia artemisiifolia (ragweed) and Artemisia vulgaris (mugwort). Initially, nsLTP sensitization appeared to be limited to Mediterranean countries, however more recent studies suggest clinically relevant sensitization occurs in North Atlantic regions and also countries in Northern Europe, with nsLTP sensitisation profiles being broadly similar.

Discussion

These robust allergens have the potential to sensitize and provoke symptoms to a large number of plant foods, including those which are raw, cooked or processed. It is unknown why some sensitized individuals develop clinical symptoms to foods whereas others do not, or indeed what other allergens besides Pru p 3 may be primary sensitising allergens. It is clear that these allergens are also relevant in non‐Mediterranean populations and there needs to be more recognition of this.

Conclusion

Non‐specific LTP allergens, present in a wide variety of plant foods and pollens, are structurally robust and so may be present in both raw and cooked foods. More studies are needed to understand routes of sensitization and the world‐wide prevalence of clinical symptoms associated with sensitization to these complex allergens.

Occupational Allergies to Cannabis

Within the last decade there has been a significant expansion in access to cannabis for medicinal and adult nonmedical use in the United States and abroad. This has resulted in a rapidly growing and diverse workforce that is involved with the growth, cultivation, handling, and dispensing of the cannabis plant and its products. The objective of this review was to educate physicians on the complexities associated with the health effects of cannabis exposure, the nature of these exposures, and the future practical challenges of managing these in the context of allergic disease. We will detail the biological hazards related to typical modern cannabis industry operations that may potentially drive allergic sensitization in workers. We will highlight the limitations that have hindered the development of objective diagnostic measures that are essential in separating "true" cannabis allergies from nonspecific reactions/irritations that "mimic" allergy-like symptoms. Finally, we will discuss recent advances in the basic and translational scientific research that will aid the development of diagnostic tools and therapeutic standards to serve optimal management of cannabis allergies across the occupational spectrum.

Immunomodulation by cannabinoids: Current uses, mechanisms, and identification of data gaps to be addressed for additional therapeutic application

The endocannabinoid system plays a critical role in immunity and therefore its components, including cannabinoid receptors 1 and 2 (CB₁ and CB₂), are putative druggable targets for immune-mediated diseases. Whether modulating endogenous cannabinoid levels or interacting with CB₁ or CB₂ receptors directly, cannabinoids or cannabinoid-based therapeutics (CBTs) show promise as anti-inflammatory or immune suppressive agents. Herein we provide an overview of cannabinoid effects in animals and humans that provide support for the use of CBTs in immune-mediated disease such as multiple sclerosis (MS), inflammatory bowel disease (IBD), asthma, arthritis, diabetes, human immunodeficiency virus (HIV), and HIV-associated neurocognitive disorder (HAND). This is not an exhaustive review of cannabinoid effects on immune responses, but rather provides: (1) key studies in which initial and/or novel observations were made in animal studies; (2) critical human studies including meta-analyses and randomized clinical trials (RCTs) in which CBTs have been assessed; and (3) evidence for the role of CB₁ or CB₂ receptors in immune-mediated diseases through genetic analyses of single nucleotide polymorphisms (SNPs) in the CNR1 and CNR2 genes that encode CB₁ or CB₂ receptors, respectively. Perhaps most importantly, we provide our view of data gaps that exist, which if addressed, would allow for more rigorous evaluation of the efficacy and risk to benefit ratio of the use of cannabinoids and/or CBTs for immune-mediated diseases.

Review of NIOSH Cannabis-Related Health Hazard Evaluations and Research

Since 2004, the National Institute for Occupational Safety and Health (NIOSH) has received 10 cannabis-related health hazard evaluation (HHE) investigation requests from law enforcement agencies (n = 5), state-approved cannabis grow operations (n = 4), and a coroner's office (n = 1). Earlier requests concerned potential illicit drug exposures (including cannabis) during law enforcement activities and criminal investigations. Most recently HHE requests have involved state-approved grow operations with potential occupational exposures during commercial cannabis production for medicinal and non-medical (recreational) use. As of 2019, the United States Drug Enforcement Administration has banned cannabis as a Schedule I substance on the federal level. However, cannabis legalization at the state level has become more common in the USA. In two completed cannabis grow operation HHE investigations (two investigations are still ongoing as of 2019), potential dermal exposures were evaluated using two distinct surface wipe sample analytical methods. The first analyzed for delta-9-tetrahydrocannabinol (Δ9-THC) using a liquid chromatography and tandem mass spectrometry (LC-MS-MS) method with a limit of detection (LOD) of 4 nanograms (ng) per sample. A second method utilized high performance liquid chromatography with diode-array detection to analyze for four phytocannabinoids (Δ9-THC, Δ9-THC acid, cannabidiol, and cannabinol) with a LOD (2000 ng per sample) which, when comparing Δ9-THC limits, was orders of magnitude higher than the LC-MS-MS method. Surface wipe sampling results for both methods illustrated widespread contamination of all phytocannabinoids throughout the tested occupational environments, highlighting the need to consider THC form (Δ9-THC or Δ9-THC acid) as well as other biologically active phytocannabinoids in exposure assessments. In addition to potential cannabis-related dermal exposures, ergonomic stressors, and psychosocial issues, the studies found employees in cultivation, harvesting, and processing facilities could potentially be exposed to allergens and respiratory hazards through inhalation of organic dusts (including fungus, bacteria, and endotoxin) and volatile organic compounds (VOCs) such as diacetyl and 2,3-pentanedione. These hazards were most evident during the decarboxylation and grinding of dried cannabis material, where elevated job-specific concentrations of VOCs and endotoxin were generated. Additionally, utilization of contemporary gene sequencing methods in NIOSH HHEs provided a more comprehensive characterization of microbial communities sourced during cannabis cultivation and processing. Internal Transcribed Spacer region sequencing revealed over 200 fungal operational taxonomic units and breathing zone air samples were predominantly composed of Botrytis cinerea, a cannabis plant pathogen. B. cinerea, commonly known as gray mold within the industry, has been previously associated with hypersensitivity pneumonitis. This work elucidates new occupational hazards related to cannabis production and the evolving occupational safety and health landscape of an emerging industry, provides a summary of cannabis-related HHEs, and discusses critical lessons learned from these previous HHEs.

An emerging allergen: Cannabis sativa allergy in a climate of recent legalization

Considering its recent legalization in Canada, the health implications of Cannabis sativa exposure, including allergy, are coming to the forefront of medical study and interest. C. sativa allergy is an issue that affects recreational users of the substance, processors, agricultural workers, and contacts of Cannabis aeroallergens and secondhand product. Allergies to C. sativa are heterogenous and span the spectrum of hypersensitivity, from dermatitis to rhinoconjunctivitis to life-threatening anaphylaxis. Due to its recent legalization, sensitized individuals will have increasing exposure from direct contact to agricultural pollens. Diagnosis and treatment of Cannabis allergy are developing fields that are already showing promise in the identification of culprit antigens and the potential for immunotherapy; however, much responsibility still falls on clinical diagnosis and symptom management. Hopefully, given the current explosion of interest in and use of Cannabis, C. sativa allergy will continue to garner awareness and therapeutic strategies.

Cannabis-Associated Asthma and Allergies

Inhalation of cannabis smoke is its most common use and the pulmonary complications of its use may be the single most common form of drug-induced pulmonary disease worldwide. However, the role of cannabis consumption in asthma patients and allergic clinical situations still remains controversial. To review the evidence of asthma and allergic diseases associated with the use of marijuana, we conducted a search of English, Spanish, and Portuguese medical using the search terms asthma, allergy, marijuana, marihuana, and cannabis. Entries made between January 1970 and March 2017 were retrieved. Several papers have shown the relationship between marijuana use and increase in asthma and other allergic diseases symptoms, as well as the increased frequency of medical visits. This narrative review emphasizes the importance to consider cannabis as a precipitating factor for acute asthma and allergic attacks in clinical practice. Although smoking of marijuana may cause respiratory symptoms, there is a need for more studies to elucidate many aspects in allergic asthma patients, especially considering the long-term use of the drug. These patients should avoid using marijuana and be oriented about individual health risks, possible dangers of second-hand smoke exposure, underage use, safe storage, and the over smoking of marijuana.

Occupational cannabis exposure and allergy risks

Objectives

Cannabis allergy has mainly been described following recreational use but some cases also point to cannabis sensitisation as a result of occupational exposure. As a consequence, little is known on the prevalence and clinical phenotype of occupational cannabis allergy. Therefore, this study aims to explore the allergy-associated health risks of occupational cannabis exposure in Belgian police force personnel.

Methods

81 participants, active in the police force, reporting regular occupational cannabis exposure during the past 12 months, were included. History was combined with a standardised questionnaire on allergies and cannabis exposure.Basophil activation tests (BATs) with a crude cannabis extract and rCan s 3 were performed. In addition, specific (s)IgE rCan s 3 as well as sIgE to house dust mite, six pollen and three mould allergens were quantified.

Results

Although 42% of the participants reported respiratory and/or cutaneous symptoms on occupational cannabis exposure, all cannabis diagnostics were entirely negative, except one symptomatic case demonstrating a borderline result. Furthermore, there is no significant difference between the groups with and without symptoms on cannabis exposure in terms of allergenic sensitisations.

Conclusions

The origins of the reported respiratory and cutaneous symptoms during cannabis exposure remain elusive but are probably due to non-immune reactions. It should be noted that the study was volunteer-based possibly reflecting an excessive number of symptomatic individuals. Nevertheless, as only one participant reported using fully protective gear, much improvement is needed for reducing the number of symptoms reported on duty, independent of their origin.

Exploring the Diagnosis and Profile of Cannabis Allergy

BACKGROUND

Cannabis allergy (CA) has mainly been attributed to Can s 3, the nonspecific lipid transfer protein (nsLTP) of Cannabis sativa. Nevertheless, standardized diagnostic tests are lacking and research on CA is scarce.

OBJECTIVE

To explore the performance of 5 cannabis diagnostic tests and the phenotypic profile of CA.

METHODS

A total of 120 patients with CA were included and stratified according to the nature of their cannabis-related symptoms; 62 healthy and 189 atopic controls were included. Specific IgE (sIgE) hemp, sIgE and basophil activation test (BAT) with a recombinant Can s 3 protein from Cannabis sativa (rCan s 3), BAT with a crude cannabis extract, and a skin prick test (SPT) with an nCan s 3-rich cannabis extract were performed. Clinical information was based on patient history and a standardized questionnaire.

RESULTS

First, up to 72% of CA reporting likely-anaphylaxis (CA-A) are Can s 3 sensitized. Actually, the Can s 3-based diagnostic tests show the best combination of positive and negative predictive values, 80% and 60%, respectively. sIgE hemp displays 82% sensitivity but only 32% specificity. Secondly, Can s 3+CA reported significantly more cofactor-mediated reactions and displayed significantly more sensitizations to other nsLTPs than Can s 3-CA. Finally, the highest prevalence of systemic reactions to plant-derived foods was seen in CA-A, namely 72%.

CONCLUSIONS

The most effective and practical tests to confirm CA are the SPT with an nCan s 3-rich extract and the sIgE rCan s 3. Can s 3 sensitization entails a risk of systemic reactions to plant-derived foods and cofactor-mediated reactions. However, as Can s 3 sensitization is not absolute, other cannabis allergens probably play a role.

Production, digestibility and allergenicity of hemp (Cannabis sativa L.) protein isolates

Hemp (Cannabis sativa L.), traditionally cultivated for industrial use and harvested for fibers and seeds, has raised much interest as a sustainable crop in the last years. Recently, hemp seeds and derived oil have started to be used in a variety of food products. Hemp-based food products are considered less allergenic than those from other edible seeds, although this statement has never been experimentally verified. In this study high purity grade hemp flour (HF) and hemp protein isolate (HPI) were obtained through a fast and cheap process starting from defatted hemp cakes, a residue of hempseed oil extraction. HPI resulted enriched at nearly 86% protein, mainly constituted by the storage protein edestin (accounting for 70% total protein). In vitro protein digestibility was determined using a static model of gastrointestinal digestion (GID), which included a final step with purified brush border membrane (BBM) enzyme preparations. HF and HPI showed a high degree of digestibility. The survival of potential bioactive and/or allergenic peptide sequences in digests was investigated by peptidomic analysis. Only a limited number of sequences survived GID. Among them, fragments from 12 seed proteins. These fragments were precursors of sequences with potential bioactive peptides, which might justify the bioactivity of HPI hydrolysates, reported in previous studies. More importantly, all known hemp allergens, including the major thaumatin-like protein and LTP, were entirely eliminated by the HPI production process, neither fragments of the proteins were present after GID. These data support the use of HPI as an ingredient for hypoallergenic foods.

[Cannabis and crossed allergy with food]

Cannabis use has increased over the last decade. At the same time, we see cannabis allergies appearing, ranging from simple rhinoconjunctivitis to anaphylactic-type reactions, some of which are severe since fatal cases have been described, but we also see allergic-induced food allergies cross-linked in the family of lipid transfer proteins (LTP). Indeed, cannabis contains an LTP called Can s 3. The LT are very widespread in the vegetable kingdom and are present in many vegetables and fruits. LTPs have a similar chemical structure and therefore cross-allergy is common. Thus, by becoming aware of the LTP of cannabis, it is possible to become allergic by a mechanism of cross-allergy to the other LTPs present in fruits and vegetables. This syndrome is referred to as cannabis-fruit-vegetable syndrome.

Cannabis sativa allergy: looking through the fog

IgE-mediated Cannabis (C. sativa, marihuana) allergy seems to be on the rise. Both active and passive exposure to cannabis allergens may trigger a C. sativa sensitization and/or allergy. The clinical presentation of a C. sativa allergy varies from mild to life-threatening reactions and often seems to depend on the route of exposure. In addition, sensitization to cannabis allergens can result in various cross-allergies, mostly for plant foods. This clinical entity, designated as the 'cannabis-fruit/vegetable syndrome', might also imply cross-reactivity with tobacco, natural latex and plant-food-derived alcoholic beverages. Hitherto, these cross-allergies are predominantly reported in Europe and appear mainly to rely upon cross-reactivity between nonspecific lipid transfer proteins or thaumatin-like proteins present in C. sativa and their homologues, ubiquitously distributed throughout plant kingdom. At present, diagnosis of cannabis-related allergies predominantly rests upon a thorough history completed with skin testing using native extracts from crushed buds and leaves. However, quantification of specific IgE antibodies and basophil activation tests can also be helpful to establish correct diagnosis. In the absence of a cure, treatment comprises absolute avoidance measures. Whether avoidance of further use will halt the extension of related cross-allergies remains uncertain.

Cannabis Allergy: What do We Know Anno 2015

For about a decade, IgE-mediated cannabis (marihuana) allergy seems to be on the rise. Both active and passive exposure to cannabis allergens may lead to a cannabis sensitization and/or allergy. The clinical manifestations of a cannabis allergy can vary from mild to life-threatening reactions, often depending on the route of exposure. In addition, sensitization to cannabis allergens can trigger various secondary cross-allergies, mostly for plant-derived food. This clinical entity, which we have designated as the "cannabis-fruit/vegetable syndrome" might also imply cross-reactivity with tobacco, latex and plant-food derived alcoholic beverages. These secondary cross-allergies are mainly described in Europe and appear to result from cross-reactivity between non-specific lipid transfer proteins or thaumatin-like proteins present in Cannabis sativa and their homologues that are ubiquitously distributed throughout plant kingdom. At present, diagnosis of cannabis-related allergies rests upon a thorough history completed with skin testing using native extracts from buds and leaves. However, quantification of specific IgE antibodies and basophil activation tests can also be helpful to establish correct diagnosis. In the absence of a cure, treatment comprises absolute avoidance measures including a stop of any further cannabis (ab)use.

Transport of Pru p 3 across gastrointestinal epithelium - an essential step towards the induction of food allergy?

BACKGROUND

Since intestinal absorption of food protein can trigger an allergic reaction, the effect of plant food allergen on intestinal epithelial cell permeability and its ability to cross the epithelial monolayer was evaluated.

OBJECTIVE

To study the interaction of Pru p 3 with intestinal epithelium, its natural entrance, analyzing transport kinetics and cellular responses that trigger.

METHODS

This was achieved using Pru p 3, the peach LTP, as a model. Enterocytic monolayers were established by culturing Caco 2 cells, as a model of enterocytes, on permeable supports that separate the apical and basal compartments. Pru p 3 was added to the apical compartment, the transepithelial resistance (TEER) was measured, and the transport was quantified.

RESULTS

The peach allergen that crossed the cell monolayer was detected in the cell fraction and in the basal medium by immunodetection with specific antibodies and the quantity was measured by ELISA assay. Pru p 3 was able to cross the monolayer without disturbing the integrity of the tight junctions. This transport was significantly higher than that of a non-allergenic peach LTP, LTP1, and occurred via lipid raft pathway. The incubation of Caco 2 cells with Pru p 3 and LTP1 produced the expression of epithelial-specific cytokines TSLP, IL33 and IL25.

CONCLUSION

These results suggest that Pru p 3 was able to cross the cell monolayer by the transcellular route and then induce the production of Th2 cytokines. The results of the present study represent a step towards clarifying the importance of Pru p 3 as a sensitizer.

CLINICAL RELEVANCE

The capacity of food allergens to cross the intestinal monolayer could explain their high allergenic capacity and its fast diffusion through the body associating to severe symptoms.

The role of N-glycosylation in kiwi allergy

The physical, biochemical, and immunological characteristics of plant allergens have been widely studied, but no definite conclusion has been reached about what actually makes a protein an allergen. In this sense, N-glycosylation is an exclusive characteristic of plant allergens not present in mammals and it could be implied in allergenic sensitization. With this aim, we evaluated and compared the allergenic activity of the protein fraction and the N-glycan fraction of the thaumatin-like protein and the main kiwi allergen, Act d 2. The natural allergen, Act d 2, was deglycosylated by trifluoromethanesulfonic acid treatment; the N-glycan fraction was obtained by extended treatment with proteinase K. N-glycan- and protein- fractions were recognized by specific IgE of kiwi-allergic patients. By contrast, the sugar moiety showed a reduced capacity to activate basophils and T cells, but not dendritic cells derived from patients' monocytes. Related to this, the production of cytokines such as IL6 and IL10 was increased by the incubation of dendritic cells with sugar moiety. Thus, the sugar moiety plays a significant role in sensitization, inducing the activation of antigen-presenting cells, but it is the protein fraction that is responsible for the allergic reactions.

Allergenic characterization of new mutant forms of Pru p 3 as new immunotherapy vaccines

Nowadays, treatment of food allergy only considered the avoidance of the specific food. However, the possibility of cross-reactivity makes this practice not very effective. Immunotherapy may exhibit as a good alternative to food allergy treatment. The use of hypoallergenic molecules with reduced IgE binding capacity but with ability to stimulate the immune system is a promising tool which could be developed for immunotherapy. In this study, three mutants of Pru p 3, the principal allergen of peach, were produced based on the described mimotope and T cell epitopes, by changing the specific residues to alanine, named as Pru p 3.01, Pru p 3.02, and Pru p 3.03. Pru p 3.01 showed very similar allergenic activity as the wild type by in vitro assays. However, Pru p 3.02 and Pru p 3.03 presented reduced IgE binding with respect to the native form, by in vitro, ex vivo, and in vivo assays. In addition, Pru p 3.03 had affected the IgG4 binding capacity and presented a random circular dichroism, which was reflected in the nonrecognition by specific antibodies anti-Pru p 3. Nevertheless, both Pru p 3.02 and Pru p 3.03 maintained the binding to IgG1 and their ability to activate T lymphocytes. Thus, Pru p 3.02 and Pru p 3.03 could be good candidates for potential immunotherapy in peach-allergic patients.

Prevalence of sensitization to Cannabis sativa. Lipid-transfer and thaumatin-like proteins are relevant allergens

BACKGROUND

Although allergy to Cannabis sativa was first reported over 40 years ago, the allergenicity has scarcely been studied. The objectives of this study were to investigate the frequency of sensitization to this plant, to analyze the clinical characteristics and allergenic profile of sensitized individuals and to identify the allergens involved.

METHODS

Five hundred and forty-five individuals in Spain attending allergy clinics with respiratory or cutaneous symptoms underwent a skin-prick test (SPT) with C. sativa leaf extract. The extract was characterized by SDS-PAGE and 2-dimensional electrophoresis. Specific IgE to C. sativa was measured in positive SPT individuals. The clinical and allergenic profiles of sensitized individuals were investigated and the most-recognized allergens sequenced and characterized by liquid chromatography-mass spectrometry/mass spectrometry.

RESULTS

Of this preselected population, 44 individuals had positive SPT to C. sativa (prevalence 8.1%). Prevalence was higher in individuals who were C. sativa smokers (14.6%). Two individuals reported mild symptoms with C. sativa. Twenty-one individuals from 32 available sera (65.6%) had positive specific IgE to C. sativa. Twelve sera recognized at least 6 different bands in a molecular-weight range of between 10 and 60 kDa. Six of them recognized a 10-kDa band, identified as a lipid transfer protein (LTP) and 8 recognized a 38-kDa band, identified as a thaumatin-like protein.

CONCLUSIONS

There is a high prevalence of sensitization to C. sativa leaves. The clinical symptoms directly attributed to C. sativa were uncommon and mild. The sensitization profile observed suggests that C. sativa sensitization may be mediated by two mechanisms, i.e. cross-reactivity, mainly with LTP and thaumatin-like protein, and exposure-related 'de novo' sensitization.

Characterization of Cannabis sativa allergens

BACKGROUND

Allergic sensitization to Cannabis sativa is rarely reported, but the increasing consumption of marijuana has resulted in an increase in the number of individuals who become sensitized. To date, little is known about the causal allergens associated with C sativa.

OBJECTIVE

To characterize marijuana allergens in different components of the C sativa plant using serum IgE from marijuana sensitized patients.

METHODS

Serum samples from 23 patients with a positive skin prick test result to a crude C sativa extract were evaluated. IgE reactivity was variable between patients and C sativa extracts. IgE reactivity to C sativa proteins in Western blots was heterogeneous and ranged from 10 to 70 kDa. Putative allergens derived from 2-dimensional gels were identified.

RESULTS

Prominent IgE reactive bands included a 23-kDa oxygen-evolving enhancer protein 2 and a 50-kDa protein identified to be the photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase. Additional proteins were identified in the proteomic analysis, including those from adenosine triphosphate synthase, glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, and luminal binding protein (heat shock protein 70), suggesting these proteins are potential allergens. Deglycosylation studies helped refine protein allergen identification and demonstrated significant IgE antibodies against plant oligosaccharides that could help explain cross-reactivity.

CONCLUSION

Identification and characterization of allergens from C sativa may be helpful in further understanding allergic sensitization to this plant species.

A mutant of the major melon allergen, Cuc m 2, with reduced IgE binding capacity is a good candidate for specific immunotherapy

Hypoallergenic mutants with reduced IgE-binding capacity but which show a similar T-cell response to the corresponding natural allergen are ideal tools for immunotherapy, for preventing a possible anaphylactic shock. An IgE conformational epitope has been identified in Cuc m 2, the major allergen and profilin from melon. Since this epitope is highly conserved in most pollen profilins, it may contribute to an explanation of cross-reactivity between pollen and food profilins. Mutants (Mut 1 and Mut 2) were generated by changing specific residues of the Cuc m 2 epitope to alanine, produced in Escherichia coli, and purified by chromatographic methods. Mut 1 showed a slight reduction in IgE binding but an allergenic activity that was similar to recombinant Cuc m 2, as measured by basophil activation test (BAT) and skin prick test (SPT). By contrast, Mut 2 displayed a substantial reduction in IgE-binding capacity (57%) and positive responses, as determined by BAT (33%) and SPT (50%), when compared to those of rCuc m 2. However, the T-cell proliferation and cytokine production induced by Mut 2 and rCuc m 2 were similar. Thus, this mutant represent potential candidate for immunotherapy of profilin allergies.

Characterization of peach thaumatin-like proteins and their identification as major peach allergens

BACKGROUND

Peach is the most important fruit related to food allergy in the Mediterranean area. Pru p 3, its lipid transfer protein, has been described as the principal allergen responsible for cross-reactivities with other foods and pollen and the severity of clinical symptoms. However, the involvement of other allergenic families cannot be ruled out. Thaumatin-like proteins (TLPs) have been described as food allergen in several fruits, such as apple, cherry, kiwi and banana, and pollen.

OBJECTIVE

To identify members of the TLP family in peach fruit and to characterize putative allergens.

METHODS

Through two-dimensional (2D) electrophoresis of peach extract and immunodetections with a pool of peach-allergic patients, IgE-binding spots were identified and the corresponding proteins purified and characterized as allergens by in vitro and in vivo assays. Three isoforms, belonging to the TLP family, were purified by different chromatographic systems and characterized by N-terminal amino acid sequences, molecular weight determination (MALDI) and enzymatic activity analysis (beta-1,3-gluconase test and inhibition growth of fungi). In the same way, their IgE-binding capacity and allergenic activity were tested by ELISA assays, basophil activation tests and skin prick tests (SPT).

RESULTS

Two peach-TLPs, Pru p 2.0101 and Pru p 2.0201, were identified as IgE-binding spots by 2D electrophoresis. Another peach-TLP, Pru p 2.0301, was cloned and produced as recombinant protein in a yeast system. The three isoforms were purified and characterized as TLPs by immunoblotting with anti-chestnut TLP antibodies and anti-plant N-asparagine complex glycan (anti-cross-reactive carbohydrate determinant). All of them showed beta-1,3-glucanase activity and inhibition of fungal growth. The three TLPs were recognized by around 50% of the sera from 31 patients analysed in ELISA experiments. All three gave a positive response to an SPT and/or in basophil activation experiments.

CONCLUSION

Three isoforms, belonging to the TLP family, were identified in peach as principal allergens. Their prevalence, observed in in vitro, ex vivo and in vivo analyses, suggests that they are important allergens and should therefore be included in the routine diagnosis of peach allergy, at least in the Mediterranean area.