Exploring the Diagnosis and Profile of Cannabis Allergy

J Allergy Clin Immunol Pract. 2019 Mar;7(3):983-989.e5. doi: 10.1016/j.jaip.2018.09.017. Epub 2018 Sep 29.

Abstract

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.

Keywords: Anaphylaxis; BAT; Basophil; Can s 3; Cannabis allergy; Cofactor; Diagnosis; Hemp; Skin prick test; Specific IgE; nsLTP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Allergens / immunology*
  • Antigens, Plant / immunology*
  • Basophil Degranulation Test
  • Basophils / immunology
  • Cannabis / immunology*
  • Carrier Proteins / immunology*
  • Female
  • Humans
  • Hypersensitivity / blood
  • Hypersensitivity / diagnosis*
  • Hypersensitivity / immunology
  • Immunoglobulin E / blood
  • Immunoglobulin E / immunology
  • Male
  • Plant Proteins / immunology*
  • Skin Tests
  • Young Adult

Substances

  • Allergens
  • Antigens, Plant
  • Can s 3 allergen, Cannabis sativa
  • Carrier Proteins
  • Plant Proteins
  • Immunoglobulin E