Allergy Testing, Immune Testing – What does it all mean?

By LuCinda Miller and Dr. Marie Starling

At The Healing Center, Dr. Starling uses many types of tests to determine the underlying issues creating symptoms in our patients. Food is one piece of your overall health and must be tested to determine what variety of problem is present, such as if it is to be permanently avoided, permanent but manageable or can be completely reset. Allergy testing varies greatly and each test looks at a slightly different piece of the picture, much like comparing apples to oranges. Today we are providing you a synopsis of some of the most common tests, what they look at, and their known strengths and limitations.

WHAT THEY LOOK AT:

IgA, IgG, IgM, and IgE

IgA, IgG, IgM, and IgE are known as Immunoglobulins or more commonly referred to as antibodies.  Immunoglobulins are secreted by the immune system in response to what the immune system perceives as a foreign invader.  These invaders can be viruses, bacteria, fungus/mold, foods, or environmental substances.   The immune system uses these Immunoglobulins to “tag” the invader to then be targeted and killed.  IgE responses are easy to diagnose as they provide immediate symptoms such as hives, rash, anaphylaxis.  IgA, IgG, and IgM reactions are more difficult to diagnose since the reaction is delayed and can occur up to 6 months after exposure.  Delayed symptoms can come on subtly and can include headaches, joint pain, and eczema to name a few.

IgA

• Considered first line of defense
• 80% of IgA is found in the body’s mucous membranes lining the respiratory and digestive tracts, also eyes and ears as well as saliva, tears and blood – any membrane that has exposure to the outside world
• Short term reaction – occurs within 0-6 months of exposure
• Tested through a blood test

IgM

• Found in blood and lymph fluid
• Short term reaction – occurs at first acute event and then normally a switch must occur from IgM production to IgA or IgG
• Tested through a blood test

IgG

• Found in all body fluids
• Smallest and most common antibodies – only antibodies able to cross the placenta from mother to baby
• Delayed sensitivity reaction occurs > 6 months of exposure
• Results in T- memory cells
• Tested through a blood test
• Test should not be positive for food
• Positive tests result in long term avoidance of foods and in some cases permanent avoidance

IgE

• Found in lungs, skin and mucous membranes
• Known as “true allergies”
• Acute reaction – rash, hives, anaphylaxis among many other immediate symptoms
• Can be environmental or food
• Tested through scratch test or RAST blood test

Mediator Release Response

Mediator Release response is the release of chemical compounds from the White Blood Cells of the immune system. These compounds trigger an inflammatory response in the body. It’s important to remember that acute inflammation is good, chronic inflammation is bad. The chemical compounds include: Cytokines

Types of Cytokines include:

• Interleukins
• Chemokines
• Tumor Necrosis Factor
• Interferons
• Leukotrienes
• Histamine
• ECP (Eosinophil Cationic Protein), MPE, Amines
• Prostaglandins

TESTING

Allergy testing is like looking through a keyhole into a room and extrapolating what the whole room looks like. All tests are inherently limited so many tests must be run to get the biggest picture of that room. Many tests for the “same” thing are looking at very different aspects and have quite specific and non-transferable meanings. This is why it can get confusing.

TESTS

Celiac Panel from Doctor’s Office

• Tests for IgA and/or IgG to Deamidated Gliadin (1 of 9 identified components of wheat)
• Tests for IgA and/or IgG to t-Transglutaminase

Tests 1 of 9 identified components of wheat, thus:

• Positive = Positive Reaction
• Negative = Inconclusive since there are 8 components not tested

Cyrex

• Tests for IgA and IgG developed in response to gluten, wheat and all of its components as well as gluten associated cross-reactive foods
• If the immune system is suppressed either one or the other IgA or IgG will usually show up. In addition, IgM can also be tested.
• More comprehensive than celiac panel conducted in the typical Doctor’s office
• As stated above, the typical celiac panel only screens for one component of wheat, deamidated gliadin, yet people can react to a single protein in wheat, or a combination of many proteins, peptides, and enzymes associated with wheat. There are 9 that have been identified.
• Cyrex Array 3 tests all 9 components of wheat
• Cyrex Array 4 tests for foods that cross-react with gluten and common food sensitivities. Positive results identify foods that must be avoided, sometimes permanently.
• The presence of IgA and IgG indicates a memory based reaction to those foods, the body does not forget and acts as if it has been vaccinated against those foods and will launch an attack when exposed.
• Permanent avoidance is necessary in some cases due to the genetic component of gluten.

Scratch Test

• Tests for IgE only
• Considered a true allergy response when positive
• Positive test provides great information however does not take other immune reactions into account (IgA, IgG, IgM and other mediator release responses), for instance if you have a negative result on a scratch test for milk, it doesn’t mean you are in the clear, you may have another type of immune reaction occurring that needs to be addressed.

LEAP and Alcat

• Tests sensitivities, not allergies
• Tests Mediator Release Response which measures general immune reaction to food and food chemicals
• Great for identifying foods that trigger inflammatory response on a short term basis
• Will not provide long term ramifications of exposure to gluten and its cross-reactive foods

US BioTek

• Tests IgE, IgG, and IgA of 96 foods
• Comprehensive food panel including grains, fruit, dairy, legumes, nuts, meat, fowl, spices, fish
• Does not test for all gluten cross-reactive foods

IN CONCLUSION:

Remember, food issues occur as a result of a primary cause such as leaky gut, adrenal fatigue, acute infection, chronic  blood sugar issues, hormone changes, concussion/TBI (Traumatic Brain Injury), inherited antibodies at birth to name a few.  These issues must also be addressed to completely fix or manage a complicated health picture, treating only one will not be enough.

Bottom line is if you are experiencing symptoms, there are many mechanisms in your body that can be malfunctioning to contribute to the state of your health.  For example, if you have been diagnosed with Celiac, are diligent about avoiding gluten but are still experiencing symptoms, there are other pieces at play here. We are here to identify all the areas of break down, provide you care and show you how to manage your health.