Friday, May 7, 2010

Immunoglobulins

I've thrown around the term "IgE" quite often in my posts and felt it time to take a closer look.  If a person's Immunoglobulin E (IgE) level, derived from a simple blood test, is elevated, it usually indicates a food allergy and increases with the number of allergies a person has.  I don't know Abigail's total IgE number. I just know her peanut specific IgE number.  It's the number that tells us the percent chance of her having a reaction if exposed to peanuts and is the number that will tell us if her tolerance to peanuts is improving on the study.

There are actually several Immunoglobulins, or antibodies, in our blood.  According to WebMD, antibodies are substances made by the body's immune system in response to bacteria, viruses, fungus, animal dander, or cancer cells. Antibodies attach to the foreign substances so the immune system can destroy them.  There are 5 different types:
  • IgA antibodies are found in the nose, breathing passages, digestive tract, ears, eyes, etc., and protect the body surfaces that are exposed to the outside.  Celiac disease is diagnosed using IgA antibodies as a starting point.
  • IgM antibodies are found in blood and lymph fluid and are made in response to infections.
  • IgE antibodies are found in the lungs, skin and mucous membranes.  They cause the body to react against foreign substances like pollen, dander or food.
  • IgD antibodies are found in the tissues that line the belly or chest. WebMD states that it's unclear how they work.
  • IgG antibodies are found in bodily fluids and are the most common making up 75 to 80% of all antibodies in our bodies. IgG antibodies help fight bacterial and viral infections.
According to the literature that Immuno Laboratories provided me, the majority of negative reactions to foods, or food sensitivities, with delayed symptoms are caused by IgG antibodies.  The literature states that 90% of immune reactions to foods are non-IgE.

I've been so fixated on IgE numbers that I never really paid attention to anything else.  It wasn't until I started looking closer at the difference between food allergies and food intolerances, that I realized that IgG numbers were quite important.  In my quest to now understand my own food sensitivities and those of several family members, I've been doing more research into the difference between allergies and intolerances.  In the next couple of posts I'll look closer at the symptoms of food sensitivities and the Immuno 1 Bloodprint test that identifies which foods a person is sensitive to.

On a more personal note, I went to my physician last week to discuss my symptoms which I believe are directly related to an intolerance to one or more foods.  I mentioned IgG antibodies, and she said it was something she wasn't familiar with.  She ordered an IgE food allergy test and Celiac test and then indicated that the most she could do to help was to refer me to an Allergist.  While not surprised, I'm frustrated that I have to go through the process of finding a doctor that is more knowledgeable on the subject of food sensitivities.  I haven't received the results of either test yet, but am expecting both to come back negative.