Researchers have found that the nervous system plays a key role in anaphylaxis, a severe and life-threatening allergic reaction.
- Anaphylaxis is a severe, life-threatening allergic reaction to an allergen.
- Researchers have discovered that the nervous system plays a key role in the onset of anaphylactic shock.
- This work could open the door to new treatments and better prevention of serious allergic reactions.
Anaphylaxis is a form of very severe allergic reaction to an allergen (food, venom, etc.). It is characterized by several symptoms such as hives, loss of consciousness, breathing difficulties or angioedema.
There is also a sharp drop in blood pressure and body temperature. “This response has long been attributed to sudden dilation and leakage of blood vessels”, note the researchers at Duke University. Their work, published in the journal Science Immunologybrought to light an additional mechanism: the nervous system.
Severe allergy: the nervous system responsible for the drop in temperature
Scientists arrived at this discovery by studying mice with allergic reactions. They followed the sequence of events that occurs when allergens activate mast cells, the immune cells that trigger the chemical reactions that lead to the symptoms of anaphylaxis.
They noticed that one of the chemicals released by mast cells is an enzyme that interacts with sensory neurons, including those involved in the body’s thermoregulatory neural network.
“When stimulated as part of an allergic reaction, this neural network receives the signal to immediately shut down the body’s heat generators in brown adipose tissue, causing hypothermia. Activation of this network also causes a drop sudden blood pressure”indicate the authors in a communicated.
Anaphylactic shock: new targets for therapies
The role of the nervous system in anaphylaxis, and its most severe form, anaphylactic shock, was confirmed by the team in an experiment with mice. Rodents that were deprived of this mast cell-specific enzyme were protected against hypothermia. On the other hand, the direct activation of the neurons which were sensitive to it, led to anaphylactic reactions such as hypothermia and hypotension.
“By demonstrating that the nervous system is a key player – not just immune cells – we now have potential targets for prevention or therapy”explained Chunjing Evangeline Bao, first author of the works presented. “This finding could also be important for other conditions, including septic shock”she added.