allergensproteins

Allergen proteins are naturally occurring proteins that can provoke IgE-mediated allergic reactions in people who are sensitized. They occur in foods (peanuts, milk, eggs), pollens (birch), mites, insects, and animal dander. Not all proteins are allergens; those that trigger clinically relevant responses are typically stable, present in sufficient quantities, and capable of being recognized by the immune system.

In susceptible individuals, exposure leads to the production of specific IgE antibodies against epitopes on the allergen. Upon re-exposure, IgE bound to mast cells and basophils cross-links, releasing mediators that cause symptoms from itching and hives to anaphylaxis. Cross-reactivity can occur when different proteins share similar structures, causing reactions to related foods or pollens.

Allergen proteins are categorized into several families, including seed storage proteins in nuts and legumes; non-specific lipid transfer proteins; profilins; PR-10 proteins such as Bet v 1; tropomyosin in shellfish and crustaceans; and proteases such as Der p 1 from dust mites. Specific molecules within these families are often used in diagnosis and research.

Diagnosis relies on skin prick tests, serum specific IgE testing, or component-resolved diagnostics using individual allergen molecules. The gold standard for food allergies is an oral food challenge performed under medical supervision. Management centers on avoidance, emergency planning, and, in some cases, immunotherapy for aeroallergens.