Allergenic Risk Assessment of Hemp Seed

All study-specific examinations are performed during the enrollment visit, which takes place during a routine medical visit

• blood sample and skin prick tests (Diagnostic test): Blood sample and skin prick tests in addition to the blood tests and skin prick tests originally scheduled for the patient's care

Primary outcomes

• Proportion of patients sensitized to hemp seeds in 3 differents population of patients (cannabis , tree nuts and seeds allergy) [enrollment visit]: This sensitization is assessed using three independent methods, each with predefined positivity thresholds of which i) Skin prick tests using native hemp seeds with positive results defined as: Wheal diameter ≥ 6 mm and Erythema larger than the wheal A patient will be considered to have a hemp seeds allergy if the prick test is positive (regardless of the results of the other two tests) or if the other two tests are positive while the hemp seeds prick test is < 6 mm.
• Proportion of patients sensitized to hemp seeds in 3 differents population of patients (cannabis , tree nuts and seeds allergy) [enrollment visit]: This sensitization is assessed using three independent methods, each with predefined positivity thresholds of which ii) IgE reactivity to a total protein extract of hemp seed (≥ 10 ng/mL) A patient will be considered to have a hemp seeds allergy if the prick test is positive (regardless of the results of the other two tests) or if the other two tests are positive while the hemp seeds prick test is < 6 mm.
• Proportion of patients sensitized to hemp seeds in 3 differents population of patients (cannabis , tree nuts and seeds allergy) [enrollment visit]: This sensitization is assessed using three independent methods, each with predefined positivity thresholds of which iii) Basophil activation test (BAT) with a positivity threshold set at > 10% degranulation. A patient will be considered to have a hemp seeds allergy if the prick test is positive (regardless of the results of the other two tests) or if the other two tests are positive while the hemp seeds prick test is < 6 mm.

Secondary outcomes

• Proportion of patients sensitized to hemp leaves [enrollment visit]: To estimate the proportion of patients sensitized to hemp leaves among: subjects allergic or suspected of being allergic to cannabis (including hemp), subjects allergic to tree nuts (e.g., hazelnuts or walnuts), subjects allergic to seeds (e.g., sunflower, sesame, etc.)
• Describe the IgE reactivity profiles to hemp leaves [enrollment visit]: IgE reactivity profiles based on four tests : 1. total protein extract of male hemp flowers (≥ 10 ng/mL); 2. total protein extract of female hemp flowers (≥ 10 ng/mL); Commercial extracts used in routine clinical practice: 3. Hemp extract (ImmunoCAP) (> 0.35 kUA/L); 4. Can s 3 (ImmunoCAP) (> 0.35 kUA/L).
• Identify the allergenic protein components mediating IgE reactivity to hemp seeds and hemp flowers [enrollment visit]: 1. Indirect fluorometric ELISA 2. Western Blot 3. Human mast cell or humanized rat basophil assays

Sex: All, ages: 2 Years to any

Inclusion Criteria:

* Patients aged 2 years or older
* Belonging to one or more of the target populations:

  i) Individuals with known or suspected cannabis allergy: Allergy or suspected allergy to hemp seed (HS) defined by A suggestive clinical history of HS allergy and Positive skin prick test (SPT) to HS (≥ 6 mm with erythema exceeding the control papule) and/or Basophil activation test (BAT) confirming HS allergy diagnosis OR Allergy or suspected allergy to hemp flower (female or male) defined by a suggestive clinical history of hemp allergy and positive SPT to hemp flower (≥ 6 mm with erythema) and/or ImmunoCAP IgE to hemp > 0.35 KU/L ii) Individuals allergic to tree nuts (hazelnut or walnut): Allergy to walnut defined by a suggestive clinical history of IgE-mediated walnut allergy and positive SPT to walnut (≥ 8 mm) and IgE to Jug r 1, Jug r 2, or Jug r 3 > 1 KU/L and/or BAT confirming walnut allergy diagnosis OR Allergy to hazelnut defined by a suggestive clinical history of IgE-mediated hazelnut allergy and positive SPT to hazelnut (≥ 8 mm) and IgE to Cor a 9, Cor a 11, Cor a 14, or Cor a 8 > 1 KU/L and/or BAT confirming hazelnut allergy diagnosis iii) Individuals allergic to seeds (sesame, flax, pumpkin, sunflower): Allergy to sesame defined by a suggestive clinical history of IgE-mediated sesame allergy and positive SPT to sesame (≥ 6 mm) and/or IgE to sesame and/or molecular components (Ses i 1 to Ses i 7) > 0.35 KU/L and/or BAT confirming sesame allergy diagnosis OR Allergy to flaxseed defined by a suggestive clinical history of IgE-mediated flaxseed allergy and positive SPT to flaxseed (≥ 6 mm) and/or IgE to flaxseed > 0.35 KU/L and/or BAT confirming flaxseed allergy diagnosis OR Allergy to pumpkin seed defined by a suggestive clinical history of IgE-mediated pumpkin seed allergy and positive SPT to pumpkin seed (≥ 6 mm) and/or IgE to pumpkin seed > 0.35 KU/L and/or BAT confirming pumpkin seed allergy diagnosis OR Allergy to sunflower seed defined by a suggestive clinical history of IgE-mediated sunflower seed allergy and positive SPT to sunflower seed (≥ 6 mm) and/or IgE to sunflower seed > 0.35 KU/L and/or BAT confirming sunflower seed allergy diagnosis
* Patients referred to the Allergy Unit at Angers University Hospital (CHU d'Angers) for skin prick testing, either in outpatient consultation or during hospitalization
* Patients affiliated with or beneficiaries of a social security system
* Patient or legal representative having signed an informed consent form

Exclusion Criteria:

* Pregnant women or women in labor
* Individuals deprived of liberty by an administrative or judicial decision
* Individuals undergoing involuntary psychiatric care
* Adults under a legal protection measure
* Individuals unable to express their consent
* Poor understanding of the French language
* Patients whose skin reactivity prevents the interpretation of the tests