D2.318 - Don`t miss the cannabis-associated food syndrome (CAFS)

Background: Lipid transfer protein (LTP) sensitization to plant foods shows variable clinical manifestations in the presence of well-known trigger factors. There are different sensitization patterns, which can also help in identifying the sensitization route (oral/inhaled/cutaneous), enabling the identification of the primary sensitizer.

Case: We report two young men presenting with severe anaphylaxis, who were diagnosed with allergy to banana. There was no known food allergy.

Results: In the first patient, skin prick test (SPT) was positive to birch, grass, ash, pellitory and ragweed pollen, despite the patient reporting no prior respiratory symptoms. SPT to banana (prick-to-prick) was positive. The ImmunoCAP showed a type-I sensitization to banana (0.53 kU_A/L) and to the LTP marker of peach (Pru p 3, 0.58 kU_A/L) but was negative to any pollen.

The SPT / IgE serology in the second patient confirmed a type-I sensitization to birch (Bet v 1, 0.99 kU_A/L) and grass pollen (Phl p 1+5, 8.07 kU_A/L), which was consistent with the patient's history. Also, the specific IgE to banana was positive (0.49 kU_A/L) as well as to Pru p 3 (5.14 kU_A/L).

In addition to these results, we determined specific IgE to hemp and its LTP component Can s 3, which were clearly positive in both patients (patient I: sp IgE Cannabis sativa, 0.95 kU_A/L, sp. IgE rCan s 3, 1.12 kU_A/L; patient II: sp. IgE Cannabis sativa, 1.19 kU_A/L, sp. IgE rCan s 3, 3.93 kU_A/L),

Conclusion: Cannabis use is highly prevalent and is a potential source of sensitization (active and passive) to cross-reactive LTP in plant foods, which appears very likely in our two patients. Mugwort and plane tree pollen LTP sensitization was ruled out. Oral sensitization was also considered unlikely, particulary in the first patient, given he showed the highest LTP titer for Cannabis sativa. Unfortunately, the LTP of banana (Mus a 3) is not commercially available yet, so we employed Pru p 3 as an LTP food marker. Can s 3 seems to be a major component in the Cannabis sativa extract and is associated with more severe reactions to plant foods.