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Multiple food allergies after transplant linked to immunosuppessive drug

1 reply [Last post]
By Stephie's Mom on Fri, 07-21-06, 13:51

It seems that the estimated prevalence of transplant acquired food allergy (TAFA) in pediatric patients taking the drug tacrolimus is about 10-17%, whereas in adult populations, the prevalence is about 1.5%.

TAFA has also been documented to occur when the donor (or the recipient) has had no history of food allergy.

One theory as to why this is occurring at such a high rate in pediatric patients has to do with the use of a fairly new immunosuppressive drug called tacrolimus. Tacrolimus has been shown to be about 10-100 times more effective at suppressing IL-2 syntehesis (and the synthesis of other cytokines) than the older drug cyclosporine-A. I believe that food allergy after transplant was virtually unheard of when they were just using cyclosporine-A (please correct me if I'm wrong).

Turns out IL-2 is critical to the homeostasis and survival of CD4+CD25+ regulatory T cells. Perhaps a disruption of the regulatory arm of the immune system (the arm that keeps the Th1 and Th2 sides in check) concurrent with exposure to allergenic proteins can lead to the development of food allergy. That's what I'm thinking. Younger populations may be especially vulnerable to this due to the immaturity of their immune systems.
Tacrolimus inhibits IL-2 synthesis by blocking the induction of the genes coding for IL-2 and other cytokines.

Guess what else is known to inhibit IL-2 by blocking the gene expression? The aflatoxin in our peanut products that is very poorly controlled by the FDA. They even loosened the aflatoxin action levels for animal feed right before the sudden increase in PA was noted, in the late 80s. Levels of aflatoxin crop contamination increase with increases in hot, dry weather, and global warming has definitely been confirmed these past 20 years. Coincidence?

Maybe there are other environmental toxins out there that also have an immunosuppressive effect.

Here are links to articles of interest:
"Development of multiple food allergies in children taking tacrolimus after heart and liver transplantation" Pediatr Transplantation 2006: 10:380-383.

Wood GE

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By LisaM on Fri, 07-21-06, 15:22

Thanks for posting--this is very interesting.

had never heard of aflotoxin before--did a google search. here's a page with useful links:

This is a bit off topic, but sort of related:

I have a suspicion that all the chemicals in our environment play a major role--indoor pollution is a major problem now that we all live and work in airtight buildings. I recall reading an abstract in the journal of allergy and clinical immunology in which they tested the effect of low levels of formaldehyde on the expression of dust mite allergy. The formaldehyde had an effect on lung function--it made the reaction to dust mites worse in people who were already allergic! Formaldehyde is in *everything*--plywood, synthetic fabrics, carpets, cleaning supplies, etc. It is a common indoor pollutant. The concentration of formaldehyde in this study were very low--lower than the level that the World Health Organization says is an acceptable level.

(I'm sensitive to various chemical cleaners, new carpets, etc. I get hayfever like symptoms . . .and with some bathroom cleaners I have trouble sleeping because I feel like I've overdosed on caffeinated beverages. Sometimes when shopping for clothes I start having sneezing fits and feel like I'm coming down with a cold. Shoe shopping at large department stores is particularly problematic.)

The reference:
JACI. vol. 117 no. 2. S23 (i.e. it is in one of the supplement issues--in the Abstracts section). title begins: "Low Exposure to Inhaled Formaldehyde"

I'm guessing that this is one of the studies that have not fallen under the radar, so to speak. It would probably take several other studies like this to change clinical practise. But if I were an allergist, I sure would suggest that my patients with environmental allergies avoid indoor pollutants!

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