Monday, August 3, 2009

Highlights from Dr. Jones’ Talk, Part 2

Last week, I wrote about some of the food allergy topics Dr. Douglas Jones covered at our July UFAN chapter meeting. This week, as promised, I’m sharing more.

FAHF-2 research: FAHF-2 is the Chinese herbal compound that is being studied to see if it really helps prevent anaphylactic reactions to peanuts. While the compound has shown remarkable success with mice, it’s only in Phase 1 of clinical trials with humans. So while we are all keeping our fingers crossed, it will be several years before we’ll have scientific evidence that it works as well in humans as it does in mice. (Several drugs for other diseases have been successful in mice, only to prove ineffective in humans, so it really is too early to tell.) Phase 1 gathers safety data only (does this compound harm the human body?) and doesn’t test whether the compound is actually doing what it’s supposed to do. Phase 2 will measure doses and their effect on the body (more safety studies). Phase 3 will finally address the drug’s actual effectiveness against allergies in a limited group of test subjects. Phase 4 will expand to include a much larger group of test subjects, and Dr. Jones hopes to be a part of that phase, should the compound make it that far.

Probiotics: At this point, studies seem to show that probiotics don’t perform any better than a placebo in preventing food allergies. They may help eczema acutely, but there is no lasting effect beyond a month. There is data that shows giving probiotics to a woman a month before delivery and to the newborn for the first six months of life helps reduce food allergy, but ONLY if the child was delivered via C-section. If it is a vaginal delivery, then probiotics do not seem to be any better than placebo. So at this point, Dr. Jones feels like probiotics are safe, they probably won’t hurt anything, but they probably won’t accomplish anything either. More testing is needed.

Blood Serum (IgE) Testing: Formerly known as RAST, these blood serum tests measure the level of IgE antibodies in the bloodstream. In general, higher numbers indicate the likelihood that the person will react to an allergen. But interpreting the numbers on a blood serum test becomes tricky because there are three different companies that build the testing machines, and a recent study showed that the numbers produced by the three different machines can be very inconsistent. So comparing numbers from the other two machines is a bit like comparing apples to oranges. Most studies for food allergy have been done on an ImmunoCAP® machine and those are the numbers that should be used in determining when a food is to be reintroduced by food challenge or not. In Utah, Quest Diagnostics is the only lab that uses the ImmunoCAP® machine, and they accept all insurances except IHC. Most doctors aren’t aware of which labs use which machines. So don’t try to compare your blood serum numbers to your neighbor’s numbers. It’s probably better to use the results as broad guidelines, not as a firm indication of whether it is appropriate to do a food challenge on the child. Food challenges should only be done by an allergist in their office.

Once again, I can’t thank Dr. Jones enough for coming to share his knowledge with all of us. If you want to contact his office for an appointment, here’s his information:

Dr. Douglas H. Jones, MD
Rocky Mountain Allergy, Asthma, Immunology
1660 W. Antelope Dr ., Suite 310
Layton , UT 84041

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