How The Once-a-Lifetime Allergy Pill Works

The technology to treat specific allergies without injections actually has been around for over 100 years, its general principles demonstrated in clinical trials over 30 years ago. Known as sublingual tablet monotherapy, the competing method of "allergy pills" takes advantage of the fact that the lower digestive tract is the body's largest immune organ.

The lining of the digestive tract is constantly exposed to microorganisms and foreign proteins. The Gut-Associated Lymphoid Tissue, or GALT, generates white blood cells that destroy these potential invaders before they can enter the bloodstream. There is a ring of immune tissue in the throat, and there are patches, known as Peyer's patches, of immune tissue in the duodenum, jejunum, and small intestine.

When the GALT is exposed to the same allergens that trigger hay fever, there are a number of changes in the immune system:

• The immune system makes more a kind of T-cell known as the CD8+ cell and fewer of a kind of T-cell known CD4+ cells. The CD8+ cells regulate inflammation. The CD4+ cells activate inflammation. Since allergy is a process of unregulated inflammation, the shift in the balance of CD8+ and CD4+ cells reduces the severity of allergic responses, without interfering the body's fundamental ability to fight infection.
• The immune system makes more of two kinds of inflammation regulators known as IL-10 and IL-12. These substances reduce the activity of Th2 cells, white bloodc ells involved in both hay fever and asthma.
• The immune system makes less of an immune regulator known as IL-13. This allows airways to "remodel" themselves so that air passes through them more easily.

The advantage of sublingual tablet monotherapy over "allergy shots" is that it is possible to give 20 to 200 times more of the allergy-inducing substance safely, because there is no risk of the tablet causing anaphylactic shock, as there is with the shots. Occasionally, even the allergy pills cause allergic side effects, but these are generally minor, just "itchy mouth" and mild swelling, rather than closing of airways.

Over 30 countries in Europe already approve single-pill therapies for seasonal hay fever, but the FDA has been hesitant to approve similar products in the United States--and not without reason. In the USA, there are simply more kinds of grass pollen that cause allergies. European products protect against allergies to timothy grass pollen, but Americans also have a Johnson grass pollen season, a Bermuda grass pollen season, and a Sweet Vernal grass pollen season in the spring, and a ragweed pollen season in the fall. The earliest clinical trials in the USA failed to show that the products worked, probably because they didn't cover all the kinds of pollen to which test participants were exposed.

Refinements in the testing procedure now have shown that American products for timothy grass and ragweed really work, and FDA approval is probably imminent.

Is the New Allergy Pill Really for You?

There is just one catch with the new allergy treatment. Each pill (at least as they are being formulated for sale in the United States) only cures one kind of allergy. If your hay fever is caused by timothy grass or ragweed, you're in luck. If your allergy is caused by Johnson grass, Bermuda grass, or Sweet Vernal grass, or one of dozens of tree pollens, you're not in luck yet. There are multiple-allergen products in the European Union, but these treat allergies that don't occur in the United States.

Sublingual tablet monotherapy is safer, it's faster, and it's less expensive than allergy shots. It has none of the side effects of the common allergy medications.

But sublingual tablet monotherapy does not pronmise you'll never have any more allergies at all, and you have to remember to take it. One pill won't take away all your allergies for life, but just a few pills taken over a few weeks may take away your worst allergies for many years at a time, using the power of your immune system, and without side effects.