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Author Topic: Interpreting peanut/treenut rast results  (Read 3342 times)

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Offline brownie

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Interpreting peanut/treenut rast results
« on: May 26, 2015, 04:19:25 PM »
I posted on the main board about whether to challenge but maybe I should have asked for numbers specifically.  I thought I had seen a scale on the board somewhere but can't locate it.  I am confused and wondering if anyone has more information...

Where does a 0.59 rast for almond fall on the scale of anticipated seriousness / class? Well aware numbers don't necessarily predict, but is this a range to oral challenge traditionally?  The old scale I have from LabCorp states this is still Class III which seems to disagree with our current doc, who says <0.35 is undetectable and "negative".

Brownie
« Last Edit: May 26, 2015, 04:21:46 PM by brownie »
2 ds's with PA, TNA and avoiding all seafood

Offline spacecanada

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Re: Interpreting peanut/treenut rast results
« Reply #1 on: May 26, 2015, 08:48:16 PM »
The chart I had from my GP years ago (2002) is this:

ImmunoCAP RAST (units are kU/L)
Class 0 = <0.35 (absent/undetectable)
Class 1 = 0.35 - <0.7
Class 2 = 0.7 - <3.5
Class 3 = 3.5 - <17.5
Class 4 = 17.5 - <50
Class 5 = 50 - <100
Class 6 = 100+
(Multiple health sites have the same numbers.)

I remember reading and just looked up the values for 95% negative (unlikely allergic) and 95% positive (likely allergic) for different allergens.  95% negative chance of allergy level for all listed allergens on the list was 0.35 (pending reaction history). 95% positive chance of allergy levels were: Egg = 7, Peanut = 14, Milk = 15, Fish = 20, Soy = 65, Wheat = 80.  So maybe the number for 95% positive for almonds is higher than the number you received on your test, which could be the reason they want to do the challenge?

Best of luck.
ANA peanuts, tree nuts, wheat, potato, sorghum

Offline brownie

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Re: Interpreting peanut/treenut rast results
« Reply #2 on: May 26, 2015, 08:55:22 PM »
Thanks! These numbers sound more like what our current doc is reporting, which makes him a class I.  Brownie
2 ds's with PA, TNA and avoiding all seafood