Better ways to manage allergy in future

If allergies are so widespread and costly for medical services, what is being done to treat them? The University of Cambridge’s Clare Bryant...

Clare - Anybody who suffers from hay fever will of course be familiar with taking an antihistamine. So what that is is that's a drug that prevents the effect of an inflammatory mediator called histamine. So histamines are released from mast cells, which get activated by antibodies against the allergen in the body. And the histamine then produces itchy patches in your skin, produces a runny nose, produces red eyes, those kinds of things. So if you take an antihistamine, then that actually prevents those symptoms from occurring. And they're reasonably effective if you catch your allergic response fairly early. You can also take treatments such as inhaled nasal corticosteroids. They also help dampen down the immune reaction. They're a bit more preventative. And then all the way now through to something called allergen therapy, which is also known as immunotherapy. So when they know what the response is, you can give people, over a period of time, a low dose of allergy over a period of several weeks, and there seems to be a kind of immune tolerance that can come from this. When it works, it's really amazing and it's really good because that person eventually becomes tolerised or just not sensitive anymore to the allergen and the allergy symptoms go away. But obviously it's very directed against one particular protein trigger, one particular allergen trigger. And it doesn't work for everyone for reasons that we don't really understand. It's also very time consuming. And so as a consequence, immunotherapy as it's called is useful, but it's unfortunately not proven to be the great panacea that we all hoped it would be.

Will - And now that brings us to your line of research. We are hoping to hide the allergen from the body altogether.

Clare - We found, sort of a bit by mistake really, several years ago that the cat allergy protein was actually detected by a receptor in the body, so that's a protein that's on the cell membrane of immune cells, called toll-like receptor 4. This protein could actually detect the cat allergy protein and this then was contributing to part of the way in which an immune response against an allergy was generated. And it transpired the same protein could also detect house dust mite proteins and proteins from pollens. And this triggered us to actually go and look for drugs that could inhibit toll-like receptor 4. So the rationale being that if you took a drug that blocked toll-like receptor 4, it would then stop the allergy and being detected by the body, which would stop the aberrant immune response, the allergic to communal response from occurring.

Will - You're almost hiding the response from the body, is that what you're saying?

Clare - Yeah, you're hiding the allergen from the body. So it becomes useful as a preventative therapy. So imagine you're going into a house where somebody, your friends, got pet cats and you were allergic to them. You could take a dose of TLR4 antagonist, and when you went into the house because your receptors were blocked, your body wouldn't see the allergen protein from the cat and you wouldn't get an allergen response occurring. Because this receptor was common to many allergy proteins, then you go, okay, well this actually could be quite useful as a prevention. When you're going into an environment where, you know, the allergens are going to be.

Will - And if you were to put your super optimist hat on as a final thought, do you think we'll ever get to the stage where allergies might be removed from the human body altogether?

Clare - I hope so. Yes. We need to understand much more about the biology and I think things are now emerging that we're really starting to understand the biology much, much better, particularly with the genetic studies and the patient biobanks and all those kinds of things. As the genomic era pans out, I think we will stand a good chance of trying to understand some of the common triggers, which will then allow us to design a much more rational therapeutic strategy against allergies and potentially vaccines, which may be a bit more pan specific because often people who have one allergy have an allergy against many different allergen proteins. So that's kind of the great hope moving forward.

Will - So everyone who has horrible hay fever right now, there is a shred of hope.

Clare - There is a shred of hope. Yes, horrible hay fever, horrible allergies to pets. Our preventative therapy will hopefully help that if we're successful. In the long term, hopefully by understanding the biology of how allergies occur, there are potential to develop new therapies. But in the meantime, I'm afraid we just have to grin and bear it.