Exploring the diagnosis and profile of cannabis allergy

Publication date: Available online 29 September 2018

Source: The Journal of Allergy and Clinical Immunology: In Practice

Author(s): Ine Ilona Decuyper, Athina Ludovica Van Gasse, Margaretha A. Faber, Jessy Elst, Christel Mertens, Hans-Peter Rihs, Margo M. Hagendorens, Vito Sabato, Hilde Lapeere, Chris H. Bridts, Luc S. De Clerck, Didier Gaston Ebo

ABSTRACT

Background

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

Objective

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

Methods

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

Results

Firstly, 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 a nCan s 3-rich extract and the sIgE rCan s 3. Can s 3 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.