RAST level dropped dramatically in 1 year!

Posted on: Thu, 02/09/2006 - 11:29pm
JacksonsMom's picture
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Joined: 07/21/2002 - 09:00

It's been a while since I've posted - the last several months have been crazy here (I had a baby in December). Anyway , I was wondering if this has happened to anyone else and what , if anything, it means.

A little history: My 3 year old son was first RAST tested a year ago after his first reaction to peanuts. His Cap Rast number was 97.6 - class 6. His SPT was 4+ positive. Since then we have not had any exposures (that we know of) or reactions. (A few minor cases of hives, but he is also TNA, Sesame, soy, peach, legume, and dog and cat allergic) so the hives could have been from almost anything.

Now the good news; we just re-tested and his cap Rast level is 42.8. Still a class 6, but down by more than 50% !! I am so happy, but I know that this really doesn't mean anything. Or does it? Our allergist just said that we are obviously doing a good job at keeping him from being exposed. When I asked if this could mean he may grow out of the allergy she gave him a 20% chance. Last year - when the result was 97 she gave him NO chance of outgrowing.

Has this happened to anyone? Did your numbers continue to go down? Or could they bounce back up next time? Could the number originally have been so high because we drew the blood within days of a reaction?

It just seems to be a huge difference in only one year. I should mention that his first reaction was contact/smell and not ingestion. He has never actually eaten peanut or peanut butter. So we know that he is VERY sensitive.

Thanks in advance for any info!

Posted on: Fri, 02/10/2006 - 12:49am
samirosenjacken's picture
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Joined: 09/30/2002 - 09:00

I found these levels for you:
IgE conc (kU/L) <0.10 Class O Negative
0.10 - 0.34 Class 0/1 Equivocal/Borderline
0.35 - 0.69 Class 1 Low Positive
0.70 - 3.4 Class 2 Moderate Positive
3.5 - 17.4 Class 3 High Positive
17.5 - 49.9 Class 4 Very High Positive
50.0 - 99.9 Class 5 Very High Positive
>100 Class 6 Very High Positive
If you child is now a 42 that means it's a class 4... not a class 6.. still considered very high.
My DD went from >100 2 years in a row to dropping down to a 44 class 4. I immediately called Dr. Wood thinking we were on the way down and that was good news. He basically told me to relax. That even tho the numbers dropped, that didn't mean a whole lot. She was still severely allergic, her chances of outgrowing it were slim to none and that we weren't to change one thing we were doing. Sure enough, one year later she was back up to a class 5.
We are very cautious so the only contact she ever gets with peanut is by school or playgrounds etc.. she never eats anything that is cross contaminated...

Posted on: Fri, 02/10/2006 - 1:26am
SaraM's picture
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Joined: 05/23/2005 - 09:00

My dd's RAST went from >100 at age 2 to 25 at age 3. They told me she could still outgrow it (although they told me that when it was over 100, too). My understading is that RAST scores just aren't very predictive of severity of reaction or liklihood of outgrowing the allergy (unless it goes below .35). So, although I try to not get too excited (I know it could go back up and may not mean much anyway), it's really hard not to!
------------------
Sara

Posted on: Fri, 02/10/2006 - 2:09am
Corvallis Mom's picture
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Joined: 05/22/2001 - 09:00

Well, our RAST numbers have fluctuated (not wildly) but severity and sensitivity have only gone, well... [b]south[/b] for lack of a more polite term.
11 mo. (blood draw days after near fatal rxn) 18 (class 3? if memory serves)
2 yr >100 (class 6)
3.5 yr 78.5 (think this is still class 6)
5.5 yr >100
We had near fatal rxns twice that we either know or suspect PN exposure. Once at 11 months and once at 2.5 yrs old.
I don't think it means much either. Our allergist required comforting from DH when he called about the 5.5 yr results. He expected us to be upset, I guess. We already knew that the allergy wasn't getting better. Like others, her only exposures that we are aware of are very tiny ones from aerosols and trace contact on public surfaces.
I really think that if you have had an anaphylactic reaction, and your RAST is above 25 or 30, you are severely allergic and you are likely to be exquisitely sensitive TOO. That is all it seems to mean. We noticed NO improvement in sensitivity during the period that the antibody levels were slightly lower.
I might be encouraged if the numbers kept going down, or if I had a remotely reasonably reason for why they go up again... but I don't. [img]http://uumor.pair.com/nutalle2/peanutallergy/frown.gif[/img]

Posted on: Fri, 02/10/2006 - 2:20am
ajgauthier's picture
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Joined: 04/13/2005 - 09:00

Quote:Originally posted by samirosenjacken:
[b]I found these levels for you:
IgE conc (kU/L) <0.10 Class O Negative
0.10 - 0.34 Class 0/1 Equivocal/Borderline
0.35 - 0.69 Class 1 Low Positive
0.70 - 3.4 Class 2 Moderate Positive
3.5 - 17.4 Class 3 High Positive
17.5 - 49.9 Class 4 Very High Positive
50.0 - 99.9 Class 5 Very High Positive
>100 Class 6 Very High Positive
If you child is now a 42 that means it's a class 4... not a class 6.. still considered very high.
My DD went from >100 2 years in a row to dropping down to a 44 class 4. I immediately called Dr. Wood thinking we were on the way down and that was good news. He basically told me to relax. That even tho the numbers dropped, that didn't mean a whole lot. She was still severely allergic, her chances of outgrowing it were slim to none and that we weren't to change one thing we were doing. Sure enough, one year later she was back up to a class 5.
We are very cautious so the only contact she ever gets with peanut is by school or playgrounds etc.. she never eats anything that is cross contaminated...
[/b]
Just a bit more info on levels. The actual "Class" level comes from the specific lab that did your test. Depending what method and materials they used, and depending on the overall IgE in the blood, they make the classification system into the Classes. It's not standard between labs. My allergist gave me that bit of info.
However, the results "as a Class number" are somewhat standard. So, Class V from my lab here in Tucson and with my blood is equivalent to a Class V somewhere else. It's a whole complicated formula/exponential scale thing that they do when they analyze your results and how much IgE protein was binding and how. Each person's body chemistry is different.
Adrienne :-)
------------------
30-year old survivor of severe peanut/tree nut allergy

Posted on: Fri, 02/10/2006 - 2:58am
Naer74's picture
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Joined: 11/03/2003 - 09:00

My son's CAP RAST came back negative several years ago. I will have to do a search to see exactly how many years ago it was. Just checked and it was back in 2002. Allergist wanted to do a food challenge. Son was totally scared and so we delayed it for several months. He finally agreed and then had a reaction to the food challenge. We have not had him tested again since then. I just don't think it is important for ME to know each year as I know my child would refuse to eat anything peanut anyway. Maybe in a few years I will have him CAP RAST tested again.
I hope the downward trend continues for you though. It is always exciting when we see lower #'s. Did any of the other food's decline in #'s also?
[This message has been edited by Naer74 (edited February 10, 2006).]

Posted on: Fri, 02/10/2006 - 11:22pm
JacksonsMom's picture
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Joined: 07/21/2002 - 09:00

The only other food we tested for this time was sesame, because his original result was so low - .97 , this time it was a .72 . So it is also dropping. I would love for him to outgrow sesame so that I could buy bread from the store ( I bake my own ). Too much risk for cross contamination.
Thank you all for sharing your experiences. The lab that ran our test (Quest) still considers 42 a class 6. Either way I am not going to change what I'm doing or loosen up my comfort zone. I do have a very tight comfort zone - we never eat out and I make ALL of the food he eats. He did start preschool this past fall, and we are fortunate enough to have found a nut free school, so I am just happy that he hasn't had any accidental exposures. (knock on wood)
I also want to say that without this site, I could not have made it through this last year. You guys are so supportive and full of information! THANK YOU [img]http://uumor.pair.com/nutalle2/peanutallergy/smile.gif[/img]

Posted on: Fri, 02/10/2006 - 11:31pm
JacksonsMom's picture
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Joined: 07/21/2002 - 09:00

Samirosenjacken, I just checked my lab report again, and you are correct. 42 is considered a class 4. Thank you for pointing that out.

Posted on: Sun, 02/12/2006 - 1:39am
samirosenjacken's picture
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Joined: 09/30/2002 - 09:00

Adrienne
We only have two labs in our state that will run the cap rast.. they use the same levels as the one I posted. I don't think there are a lot of labs that actually run allergy tests....

Posted on: Sun, 02/12/2006 - 3:28am
ajgauthier's picture
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Joined: 04/13/2005 - 09:00

Quote:Originally posted by samirosenjacken:
[b]Adrienne
We only have two labs in our state that will run the cap rast.. they use the same levels as the one I posted. I don't think there are a lot of labs that actually run allergy tests.... [/b]
maybe where you are, but I had a choice of 4 different lab companies in Tucson alone. I had to get one of the allergens donevat one lab while the rest were done at one lab. That's where the conversation came up with my allergist about the tests being universal and such.
Adrienne
[This message has been edited by ajgauthier (edited February 12, 2006).]

Posted on: Sun, 02/12/2006 - 10:30pm
jtolpin's picture
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Joined: 05/28/2003 - 09:00

I read through this, and just have to say:
GLAD YOU HAD A SAFE YEAR!
The score went down??? GREAT!
IMO - its better than going up!
Heck with the numbers! The child is the same child they were pre-test. You should feel great for having a reaction-free (to peanut) year! Commend yourself on a job well done! Hugs for everyone!!
Jason
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[b]* Obsessed * [/b]

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