How are BDNF and allergy related?

BDNF (Brain-Derived Neurotrophic Factor) is primarily known for its role in neuronal growth and plasticity, but it also participates in immune regulation. In allergic conditions such as asthma, allergic rhinitis, and atopic dermatitis, elevated BDNF levels have been observed in serum, nasal lavage, and skin lesions. Mechanistic studies suggest BDNF can enhance mast cell degranulation and promote Th2-type inflammation, while also contributing to airway hyperresponsiveness via neuronal sensitization. However, the evidence is largely based on in vitro experiments, animal models, and small observational human studies. The clinical utility of BDNF as a biomarker or therapeutic target for allergies remains unproven. Genetic variants like BDNF Val66Met have been studied in allergy contexts, but effect sizes are small and inconsistent. Consumers should be cautious: DNA tests claiming to predict allergy risk via BDNF are not supported by robust evidence. For allergy management, standard diagnostic tests (skin prick, IgE) and medical guidance are essential.