What role does BDNF play in allergy?

BDNF (Brain-Derived Neurotrophic Factor) is primarily known for its role in the nervous system, but it is also produced by immune cells and can influence inflammatory processes. In allergies, BDNF has been linked to mast cell activation and amplification of airway inflammation, particularly in allergic asthma. However, the evidence is mostly mechanistic, derived from cell and animal studies; human clinical data are limited. A direct causal role or clinical utility for allergy diagnosis or treatment is not established. Consumer genetic tests that include BDNF variants often overstate its significance. Individual allergy susceptibility is influenced by many genes and environmental factors, so BDNF alone does not provide reliable prediction.