Prevalence Of Skin Test Reactivity To Cannabis Sativa. In Vitro Characterization Of The Extract

RATIONALE: Sensitization to C. sativa is frequent among patients sensitized to tomato. Prevalence of sensitisation remains unknown. Objectives: To determine the prevalence of skin test reactivity to C. sativa in the Mediterranean coast of Spain and to analyze the in vitro characteristics of the extract. METHODS: Five hundred and forty five adults individuals (227 males and 318 females; mean age, 39.0 ± 16.0 years) evaluated for respiratory or/and cutaneous symptoms at the Allergy Units of 5 hospitals were included in the study. All individuals were skin prick tested with a battery of common inhalant allergens (Laboratorios LETI, S.L.) and with an extract of C. sativa at 10 mg/ml. Specific IgE to C. sativa was determined by CAP. The antigenic profile was evaluated by SDS-PAGE and 2-D electrophoresis. RESULTS: The prevalence of sensitization to C. sativa was 8.1% (44/545 patients; 23M/21F, mean age, 31.9 ± 10.1 years). Forty one (93.2%) C. sativa sensitised patients were sensitised to aeroallergens, of which 37 (84.1%) to pollens. Most of the sensitized subjects (95.5%) were asymptomatic and did not report symptoms with C. sativa, (40.9% had never been in contact). Eight prominent bands (10-70 kDa) were observed in SDS-PAGE. 2D-electrophoresis showed most proteins on the neutral pH range and different isoforms at 10, 43 and 45 kDa. 66.7% of the patients had detectable specific IgE to the extract. CONCLUSIONS: The prevalence of sensitisation to C. sativa is high although most individuals were asymptomatic. Sensitisation to C. sativa is more prevalent among pollen sensitised individuals, suggesting allergen cross-reactivity.