Macadamia Nut Cross-Reactivity with Other Food Groups
| Macadamia Allergen | Cross-Reactive Food Group | Molecular Similarity (%) | Severity of Cross-Reactivity |
| Mac i 1 (11S Globulin) | Tree Nuts (Walnut, Pecan, Almond) | 85 | High |
| Mac i 2 (7S Vicillin) | Peanut, Tree Nut (Almond, Cashew) | 78 | Moderate |
| Mac i 3 (2S Albumin) | Brazil Nut, Cashew, Peanut | 92 | High |
| Mac i LTP | Rosaceae Fruits (Apple, Peach, Cherry) | 74 | Moderate |
Molecular Similarity of Macadamia Allergens with Other Food Groups
Cross-Reactivity of Macadamia Nuts with Other Food Groups
The table and bar chart above show how macadamia allergens (Mac i 1, Mac i 2, Mac i 3, Mac i LTP) compare in molecular similarity to proteins in other food groups, highlighting potential cross-reactivity risks.
Tree Nut Cross-Reactivity is High
- Mac i 1 (11S Globulin) and Mac i 2 (7S Vicilin) are highly similar to allergens in walnuts, pecans, and almonds.
- Molecular similarity:
- Mac i 1 → 85% similarity to walnut/pecan globulins.
- Mac i 2 → 78% similarity to peanut/almond vicilins.
- Implication: Individuals allergic to walnuts, pecans, or almonds may have cross-reactive IgE responses to macadamia nuts.
Mac i 3 (2S Albumin) is Highly Stable and Cross-Reactive
- Mac i 3 has 92% molecular similarity to Brazil nuts, cashews, and peanuts.
- Implication: People with severe nut allergies (including peanut allergy) should be cautious.
Mac i LTP (Lipid Transfer Protein) Cross-Reacting with Rosaceae Fruits
- 74% similarity with LTP allergens in peaches, apples, and cherries.
- Implication: Individuals with LTP syndrome (fruit allergy) may react to macadamia nuts.
Risk Levels Based on Cross-Reactivity
| Cross-Reactive Food Group | Macadamia Allergen Similarity (%) | Severity of Cross-Reactivity |
| Tree Nuts (Walnut, Pecan, Almond) | 85% | High |
| Peanuts, Cashews, Brazil Nuts | 92% | High |
| Rosaceae Fruits (Peach, Apple, Cherry) | 74% | Moderate |
Clinical Implications for Macadamia Allergy:
Clinical Implications for Macadamia Allergy:
Tree Nut Allergy Patients Should Be Cautious
- High risk for cross-reactivity with walnuts, pecans, almonds due to shared 11S Globulin and 7S Vicilin proteins.
- Macadamia nut avoidance may be necessary for tree nut–allergic individuals.
Peanut Allergy Patients May Be At Risk
- Mac i 3 (2S Albumin) shares 92% similarity with peanut storage proteins.
- Risk of anaphylactic reactions in peanut-allergic individuals.
LTP Syndrome Sufferers May Have Fruit-Nut Cross-Reactions
- LTP proteins in macadamia nuts are similar to peach, apple, and cherry allergens.
- Potential for oral allergy syndrome (OAS) or systemic reactions.