Let's back up a little and explain what OIT is and what it isn't. OIT, oral immunotherapy, IS a TREATMENT. It's a desensitization process. You start with teeny amounts of the allergen and build up to large amounts over time, tricking your body into thinking that it's not allergic. In order to maintain your desensitization, you have to continually expose your body to the allergen. So, that's why for the past several years, Brendan has eaten egg, peanut, and hazelnut EVERY. SINGLE. DAY. He has to continually remind his body that it's not allergic. OIT ISN'T a cure. We'd all LOVE to have a "cure" for food allergies. Perhaps a magic pill you could take once that would make your allergies disappear. Unfortunately, that doesn't exist. OIT isn't a "cure" because in most cases you have to eat your allergen daily to maintain your desensitization.
But what if there was some "in between state?" Somewhere between a daily treatment and an all-out cure? Well, that's what sustained unresponsiveness is. If you can go a while-- like an entire month without eating your allergens-- and then you can eat a full serving without a problem, then you've achieved sustained unresponsiveness.
So, why am I explaining all of this on a blog about my sweet boy who completed OIT a few years ago?! Because Dr. Silvers thinks Brendan may have achieved sustained unresponsiveness to both egg and hazelnut! So what's the big deal with sustained unresponsiveness? Well, if Brendan really HAS gotten there, he would be able to reduce his dosing to about three times a week instead of every day. That would be HUGE for him!
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| Here's Brendan chowing down on a cupcake on his birthday at camp this Summer. No big deal, thanks to OIT! |
It's hard to imagine that Brendan may be there with these two allergens. Here's how it's all shaken down: Before OIT, Brendan had a history of anaphylaxis to the slightest amount of egg. A single candy, with egg white as the second to last ingredient, had us using the Epi and spending the night in the hospital. He also couldn't tolerate egg in baked goods. He *almost* passed a baked egg challenge when he was 7, with just a tummy ache in the parking lot of the allergist's office. But after we tried to add baked goods into his diet, he would vomit them-- there were the brownies at the neighbor's house that didn't stay down and the roll at the luau in Hawaii that came back up before the show even started. So, Brendan couldn't tolerate any egg before we started OIT. His egg IgE was 52. His ovomucoid, which shows an allergy to the more heat stable protein in egg and often indicates a more severe, prolonged egg allergy was 18.4. Fast forward to his blood work we just got back today, and his egg white IgE is 3.93, a reduction of more than 90%! His ovomucoid has come down similarly to 1.95. Last year at his check up, his skin test for egg was negative, too. Add this to the fact that Brendan hasn't had a reaction to a dose in a LONG time-- almost two years at this point, and Dr. Silvers thinks Brendan may have made it to sustained unresponsiveness!
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| Ahh, the numbers. Brendan has always had lots of false positives on allergy testing. Look at his egg numbers now! They just look like another false positive. AMAZING! |
But what about the hazelnut?! Well, that one's a different, more complicated story. His hazelnut IgE has actually gone UP from last year. Yeah, not by a ton, but it has gone up. The key with the hazelnut is his component testing. Back when Brendan started hazelnut OIT several years ago, component testing for hazelnut was only done in research settings. Not too long after he started, it became commercially available. Allergy testing is tricky. There can be LOTS of false positives. Brendan had never ingested hazelnut before OIT, so we weren't 100% sure he had a hazelnut allergy. Component testing can help clear up the numbers a bit, but of course, it wasn't available to us when we were making the decision to try OIT. So, we played a numbers game. Brendan's hazelnut IgE was high enough that studies had found that he had a 95% chance of having a true hazelnut allergy. Dr. Silvers felt that putting him through an in office food challenge for a food he'd most likely fail wasn't a great idea, and we agreed. After all, we were doing OIT for peanut at the same time anyways, and that one WAS a real allergy-- we knew for sure thanks to peanut component testing! So, we threw hazelnut in Brendan's OIT mix, with a 95% chance he was allergic.
Still a little voice in my head always wondered. What if he was in that 5%? What if he didn't have a hazelnut allergy? So this time, I asked if we could test Brendan's hazelnut components to see if he was allergic to the "bad" components of hazelnut that cause systemic reactions or if he was just allergic to the component that might cause a slightly itchy mouth when he ate hazelnuts, but was unlikely to cause anaphylaxis. Now, these results would be tricky, because even if he tested negative to the "bad' proteins in hazelnut, we will never really know if he *was* allergic before OIT, and OIT worked and reduced his numbers, OR if his "bad" protein numbers were always low. We got the results today, and I was completely surprised. It turns out that he's allergic to the protein that may cause an itchy mouth when he eats hazelnut, but the other "bad" components are almost negative! Did he never really have a hazelnut allergy, or did OIT just work on him, reducing the levels of the "bad" components while his "itchy mouth" component (which is really related to being allergic to birch trees) has increased? We'll never know. What we do know is that those "bad" proteins are low enough that Dr. Silvers thinks he may have achieved sustained unresponsiveness to hazelnut, too!
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| So for hazelnut components, Cor a1 is indicative of a cross reaction with birch pollen. That means Brendan has a birch pollen allergy, and the proteins for the pollen allergy look enough like this specific hazelnut protein to come back positive on a test. |
So, how do we "test" for sustained unresponsiveness?! Well, it's fairly straight forward. Brendan has to stop dosing egg and hazelnut for 30 days. He also has to stop eating foods that contain egg and hazelnut during those 30 days. Bye bye donuts and Nutella. It's gonna be a tough life for 30 days. I know we lived like this for 11 YEARS before OIT, but once you've been free, it's SO hard to go back to food prison!! But we're willing to put ourselves in food jail for 30 days if that means he can reduce his dosing to just a few times a week.
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| No donuts for this boy for 30 days. Can he do it?!! It's not going to be easy! |
After our 30 days of food prison, we go in for food challenges, first to egg and then to hazelnut. Brendan will spend four hours (per food!) eating small, but increasing amounts of egg (or hazelnut) until he eats a full serving of each. If he can eat a full serving, he's done it! He's achieved sustained unresponsiveness and will be able to dose just a few times a week! If he has a reaction, we'll back up a bit from where he reacted, and he'll go home taking that dose daily. We'll slowly increase that dose, just like we did with OIT until he's back to eating his maintenance dose, and he'll have to eat that everyday for years until Dr. Silvers thinks he's ready to try for sustained unresponsiveness again. We're, of course, hoping for the former outcome!
So what about peanuts? Poor peanuts. Brendan's peanut IgE has dropped to less than 40% of what it was before OIT, but it's still not low enough to think about sustained unresponsiveness. Maybe we'll get there with peanut before he goes off to college. Maybe we'll never get there. Either way, he'll happily eat his peanuts every day until Dr. Silvers thinks he's ready to try for sustained unresponsiveness.
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| Poor peanut. Unfortunately, Ara h2 is the peanut protein most often associated with severe, systemic allergic reactions. Brendan's not quite ready to test for sustained unresponsiveness to peanuts. |
So what is sustained responsiveness? It's the hope that this TREATMENT of OIT can turn into a CURE of sorts. I remember sitting in Dr. Silvers' office nearly three and a half years ago, hearing about the hope of OIT for my sweet boy for the first time. In a few short weeks, we'll be back with Dr. Silvers again, this time with more hope than we could have ever imagined. So, we're headed back to food avoidance once more, all for the hope of even greater food FREEDOM.
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