Prevalence of Sensitization to <b><i>Cannabis sativa</i></b>. Lipid-Transfer and Thaumatin-Like Proteins Are Relevant Allergens

Abstract

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.

Cannabis Allergy: What do We Know Anno 2015

“…In our series, a positive industrial hemp sIgE test was observed in all 12 cannabis allergic patients but unfortunately also in 3 out of 8 pollen allergic patients without cannabis allergy (Ebo et al 2013). Using a whole protein extract, Larramendi et al (2013) found a positive sIgE result to a native cannabis extract in 21 out of 32 individuals who had their cannabis sensitization documented by a positive cannabis skin test. Herzinger et al (2011) found positive sIgE results to marihuana and/or hashish in two patients with professional exposure to cannabis.…”

“…Although in the study of Larramendi et al (2013), no homology was found between the 14-kDa band and any known allergen, it was speculated that this band could be a profilin (de Larramendi et al 2008).…”

“…Larramendi et al (2013) described six different bands with a molecular weight of 10-, 14-, 20-, 35-, 38-and 60-kDa that were recognized by the individual patients' sera. The 10-kDa IgE-binding band was already described in other reports (de Larramendi et al 2008;Gamboa et al 2007;Tanaka et al 1998) and most likely corresponds to Can s 3, the ns-LTP of C. sativa (Gamboa et al 2007) that belongs to the pathogenesis-related proteins (PR)-14 group (Van Loon 1999).…”

“…Presently, sensitization and allergy to cannabis are almost exclusively studied or documented by prick-prick skin testing. Prick-prick skin tests use a broad variety of raw materials such as macerated C. sativa leaves, buds and flowers de Larramendi et al 2008;Ebo et al 2013;Gamboa et al 2007;Larramendi et al 2013;Metz-Favre et al 2011;Nayak et al 2013;Stadtmauer et al 2003;Tessmer et al 2012). Needless to say, this approach is virtually impossible to standardize, mainly because of unpredictable variations in composition and potential contaminations with other allergens of the raw material.…”

Cannabis sativaallergy: looking through the fog

“…Few true IgE-dependent allergic reactions in illicit abusers have been published (7)(8)(9)(10) making it hard to determinate the true prevalence of this allergy. Nevertheless, multiple reports on cutaneous and respiratory allergies to different members of the Cannabaceae family like industrial hemp and hop (Humulus lupulus) have been published (11)(12)(13)(14)(15).…”