FAHF-2 food allergy trial was worth all the time and hassle. In a sense, the jury is still out because we don't know yet what effect the medication may have had on my son's milk allergy. (The near impossibility of getting an almost 18-year-old to stay still in one place while consuming baked milk is a topic for another blog post.) However, I also grapple with what exactly the medication did.
So why is there a creepy Orc over there, you ask? Because it seems to me that, up until this point, food allergy treatments have used a Lord of the Rings strategy. Think of the cast of characters this way:
The allergen is the Orc. Maybe he's completely misunderstood, but bad things seem to occur as soon as he hits the kingdom so, as soon as they see even one Orc, the mast cells go all nutty and light the signal fires. This starts a cascade of chemical messages throughout the body.
However, doctors don't recommend antihistamine only to treat reactions for an important reason: neither the number of Orcs or the number of Riders of Rohan determine the allergic response. It's what happens next that determines just hives...or full-out anaphylaxis...or something in-between.
However, for a sub-segment of allergic individuals, the response is way out of proportion to the threat. If the right few Orcs show up...or the right Riders reach the king...a severe response/reaction can occur. There are a couple of theories as to why. One theory is that some people have a genetic variant that causes their body to over-respond to perceived threats. Another theory is that children who are allergic to more than one hot spot on a protein are likely to have a more robust response.
Once the King and all his troops are called to the body's battlefield, it's hard to stop the war. Epinephrine is the best way. Like the Ents in the river scene in "The Two Towers", epinephrine opens up closed airways and sweeps away chemical messengers that have caused so much trouble. It also gets fluids to return to the river bed instead of running rampant through the body once all the fun is over.
So how does all this relate to the food allergy clinical trials currently underway? In almost all of these trials (oral immunotherapy, SLIT, skin patch), the idea is to just keep slipping Orcs into the body until the Riders of Rohan get used to them. After all, there are only so many times you can pelt into the hall of the king and shout "Rally the troops!" before the king stops listening.
The newest therapy on the horizon is OIT combined with omalizumab (Xolair®), a drug that works at the very beginning of the process by inserting itself into the receptors in mast cells so IgE can't bind. If you think of the Orc and the signal fire, omalizumab acts like rain on the fire wood. The signal fire never gets started, so the Riders of Rohan never ride and...well, you get the idea.
The theory is that one day, the body will wake up after therapy and see Orcs everywhere. Since there were no signal fires and no Riders of Rohan, the armies of Middle Earth will (in theory) just shrug and go "hey, guess those Orcs weren't so bad after all."
Yeah, doesn't seem like it would work to me either. But that's the theory. Some kids just seemed destined to learn to live with Orcs, so this may just be accelerating the process for those kids. For others, it may just be a faster way to learn that they're not good candidates for OIT. Only time will tell if it's all just a fantasy.
So what happens with FAHF-2?
How does it work? No one knows. Somewhere along the Yellow Brick Road, something changes. FAHF-2 works for all allergens and it works whether those allergens are in the body or not, so it's a very different model than OIT. Perhaps it reduces overall inflammation. Perhaps it promotes an environment where something missing (gut bacteria?) can get re-established. Whatever the mechanism, it does not seem to have the same overall suppressive effect on the immune system that omalizumab does.
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