Lentil allergy

Posted: 15th June 2025 | Posted by AdminMR

Lentil Allergy: Clinical Relevance of Len c 1 and Len c 3

Lentil allergy is an important food allergy concern due to its prevalence in diets across Mediterranean, Middle Eastern, Asian, and North American regions. Key lentil allergens, Len c 1 (7/8S globulin) and Len c 3 (nsLTP), are implicated in IgE-mediated hypersensitivity reactions ranging from mild oral allergy syndrome to severe anaphylaxis. Their identification is critical for accurate diagnosis and management of legume allergies.

Overview of Lentil Allergens

Lentils (Lens culinaris) contain two major protein allergens:

Len c 1 – A 7/8S globulin (gamma-vicilin seed storage protein)
Len c 3 – A non-specific lipid transfer protein (nsLTP)

Biochemical Properties

Len c 1 is the major vicilin-type allergen in lentils, commonly linked to legume-induced allergic responses. Len c 3 is a potent nsLTP, structurally stable and capable of provoking systemic reactions in sensitised individuals. Understanding these properties aids in predicting severity and cross-reactivity.

Exposure and Geographic Prevalence

Allergic reactions primarily occur via ingestion, though inhalational exposure during cooking has been reported. High prevalence areas include:

Southern Europe (Spain, Italy)
Middle East
South Asia
North America

Cross-Reactivity with Other Legumes

Len c 1 shares IgE-binding epitopes with other vicilin allergens:

Ara h 1 (peanut)
Pis s 1 (pea)
Cic a 1 (chickpea)

Len c 3 cross-reacts with Pru p 3 (peach nsLTP), relevant in LTP syndrome prevalent in southern Europe. These cross-reactivities explain overlapping allergic responses among legumes and certain fruits.

Thermal Stability and Allergenicity

Some IgE-binding proteins are heat-labile and lose allergenicity when cooked
Len c 1 and Len c 3 remain heat-stable and can provoke reactions even after boiling

Diagnostic Value of Component-Resolved Testing (CRD)

Recombinant Len c 1 and Len c 3 allow for component-resolved diagnostics:

Higher sensitivity in detecting lentil allergy
Improved risk stratification
Differentiation between true allergy and cross-reactive sensitisation

This molecular approach is particularly useful in cases involving multiple legumes.

Conclusion

Len c 1 and Len c 3 are central to lentil allergy diagnosis and management. Their structural stability and cross-reactive potential make them key targets in personalised allergy testing and risk assessment. Accurate identification improves clinical decision-making and patient outcomes.

References

Vieths S, et al. Component-resolved diagnostics for legume allergy. Allergy. 2023.
Garcia-Blanco A, et al. Thermal stability of legume vicilin allergens. Clin Exp Allergy. 2024.
Sénéchal H, et al. Cross-reactivity among edible legumes: molecular insights. Mol Immunol. 2023.

Individual allergy test for Lentil (whole allergen) is available at www.FoodAllergyTest.co.uk