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.

Influence of IL-6, IL-33, and TNF-α on human mast cell activation: Lessons from single cell analysis by flow cytometry.

BACKGROUND: Mechanisms that govern priming and degranulation of human mast cells (MCs) remain elusive. Besides, most of our knowledge is based on experiments from which data only reflect an average of all stimulated cells. This study aims at investigating the effects of proinflammatory cytokines IL-6, IL-33, and TNF-α on IgE-dependent and IgE-independent activation of individual MCs. METHODS: MCs were derived from CD34+ progenitors isolated from 50 mL whole blood from 4 healthy controls and 5 birch pollen allergic patients. Passively sensitized MCs were preincubated with IL-6, IL-33, or TNF-α and stimulated with anti-IgE/birch pollen allergen or substance P, the latter being a ligand for the G-protein-coupled MRGPRX2-receptor. Activation-i.e., upregulation of CD203c-and anaphylactic degranulation-i.e., appearance of CD63-were measured using flow cytometry. RESULTS: Preincubation with IL-33 demonstrated upregulated CD203c density without degranulation. Subsequent IgE-dependent stimulation (anti-IgE/birch pollen allergen) resulted in higher appearance of CD63 as compared to cells without preincubation, indicating IL-33 to exert a priming effect (P = 0.04). IL-6 only increased allergen-specific responses but to a lesser extent than IL-33. Combination of IL-33/IL-6 had a synergistic effect, demonstrating more degranulation in response to allergen. TNF-α had no effect on IgE-mediated activation, nor synergistic effects with IL-33. Stimulation with substance P resulted in degranulation that could not be enhanced by preincubation. CONCLUSIONS: In conclusion, IL-33, and in a lesser extent IL-6, prime individual MCs for subsequent IgE-mediated activation. Moreover, this priming effect is synergistic. In contrast, none of the cytokines had a priming effect on MRGPRX2-mediated activation of MCs. © 2017 International Clinical Cytometry Society.

Bariatric Surgery: A Novel Risk Factor for Food Allergy?

In this case report, we describe a birch pollen-allergic patient in whom a Fobi pouch gastric bypass was associated with the transition from a mild, localized, birch pollen-related oral allergy syndrome to more severe, generalized allergic reactions to peach.

State of the art and perspectives in food allergy (part II): therapy.

Currently management of food allergy is mainly based on absolute avoidance of the offending food(s) and the use of rescue medication. However, the risk of severe or life-threatening reactions due to inadvertent exposure, nutritional imbalance and social isolation raises the demand of disease-modifying treatments. The aim of the different treatments is to allow patients to safely ingest the offending food(s). However this unresponsiveness can be transient and requires continued treatment (desensitization) and has to be permanent and sustained also after stopping the treatment (tolerance). This review focuses on non-allergen specific (anti-IgE, Chinese herbal formula, etc..) and allergen specific treatments for food allergy. The anti-IgE treatment is at the moment the only non-allergen-specific therapy, for which some data on a temporarily clinical efficacy have been provided. Regarding allergen-specific treatments, different protocols (oral, sublingual, subcutaneous and epicutaneous) with natural, heat treated or recombinant food allergens have been investigated. Although promising, results of the different clinical trials are heterogeneous. In particular data on long-term effects are lacking. At the moment food specific immunotherapy can be considered an experimental interventional strategy, limited to research, and not yet ready for routine use.