Great Plains Laboratory, IgG Food Allergy Test w/ Candida (Dried Blood Spot)

IgG Food Allergy Test w/ Candida

IgG (immunoglobulin G) testing is a useful guide for structuring elimination diets in many chronic conditions. Individuals with neurological, gastrointestinal, and movement disorders often suffer from IgG food allergies. These people may continue to eat offending foods unaware of their potential effects. As immunological reactions, IgE food allergy causes the release of histamine, producing an immediate hypersensitivity reaction, in which symptoms appear within minutes or hours. In contrast, food sensitivity is a non-IgE allergy characterized by the measurement of IgG antibodies specific to antigenic food proteins. This IgG food allergy is a delayed hypersensitivity reaction in which symptoms appear anywhere from hours to days after eating the offending food. The 93 foods tested in the IgG Food Allergy Test w/ Candida can identify problem food so it can be eliminated from the patient’s diet. Elimination of IgG positive foods can improve symptoms of irritable bowel syndrome, autism, AD(H)D, cystic fibrosis, rheumatoid arthritis, and epilepsy according to numerous clinical studies.

The Great Plains Laboratory, Inc. has added Candida to the IgG Food Allergy Test. Candidaproblems are caused when the benign yeast form of Candida albicans mutates to its fungal form.Candida can take over sections of the intestinal wall causing numerous symptoms. As it grows out of balance it produces toxins that create holes in the intestinal lining, leading to leaky gut syndrome. After entering the blood, Candida albicans causes an inflammatory immune system response. A wide range of disorders have been linked to Candida including autism, multiple sclerosis, depression, and chronic fatigue. Use of antibiotics, oral contraceptives, chemotherapy, and anti-inflammatory steroids greatly increase susceptibility to Candida.

Dried Blood Spot (DBS) Collection

The IgG Food Allergy Test w/ Candida is available as a dried blood spot collection for patients and practitioners who can’t perform a blood draw. The specimen can be collected from the convenience of home and shipped to our laboratory for analysis. The dried blood spot test is the same price as the analysis.

Asian Food Allergy Test

The IgG Asian Food Allergy Test offered by The Great Plains Laboratory is designed for individuals who consume foods common to the Asian diet, especially those in China, Japan, and Korea. Analytes include mango, sunflower seeds, miso (soybean paste), and green tea.  Some of the vegetables in our general IgG Food Allergy Test have been replaced by more common Asian vegetables, such as the Shiitake mushroom, and a new food category, “spices,” has been included. The new panel also analyzes twice as many seafood items than our general test, ranging from oysters and clams to Pacific saury. The IgG Asian Food Allergy Test is a good health indicator for people who commonly eat Asian cuisine and gives a comprehensive analysis of immunological reactions to foods found in this diet.

Candida albicans Scale in IgG Food Allergy Test

The Candida albicans scale has been updated to account for the observation that Candida-specific immunoglobulins are present in the specimens of virtually all individuals tested. The new scale is intended to provide a clearer indication of clinical significance and was established according to population percentile ranks obtained from a random subset of 1,000 patients. Specifically, the range of insignificant and low IgG values correspond to the first and second quartiles of the distribution, while moderate values denote individuals in the 51st to 97.5th percentiles. Those with an IgG value greater than the 97.5th percentile are considered to have a high concentration of Candida-specific immunoglobulins.

0-25th percentile: insignificant
26th-50th percentile: low
51st-97.5th percentile: moderate
97.5th and higher: high

Total IgG versus IgG4 food allergy

Immunoglobulin G (IgG) is classified into several subclasses termed 1, 2, 3, and 4. IgGs are composed of two heavy chain–light chain pairs (half-molecules), which are connected via inter–heavy chain disulfide bonds situated in the hinge region (Figure 1). IgG4 antibodies usually represent less than 6% of the total IgG antibodies. IgG4 antibodies differ functionally from other IgG subclasses in their lack of inflammatory activity, which includes a poor ability to induce complement and immune cell activation because of low affinity for C1q (the q fragment of the first component of complement). Consequently, IgG4 has become the preferred subclass for immunotherapy, in which IgG4 antibodies to antigens are increased to reduce severe antigen reactions mediated by IgE. If antigens preferentially react with IgG4 antibodies, the antigens cannot react with IgE antibodies that might cause anaphylaxis or other severe reactions. Thus, IgG4 antibodies are often termed blocking antibodies. Another property of blood-derived IgG4 is its inability to cross-link identical antigens, which is referred to as "functional monovalency". IgG4 antibodies are dynamic molecules that exchange half of the antibody molecule specific for one antigen with a heavy-light chain pair from another molecule specific for a different antigen, resulting in bi-specific antibodies that are unable to form large cross-linked antibodies that bind complement and thus cause subsequent inflammation(16). In specific immunotherapy with allergen in allergic rhinitis, for example, increases in allergen-specific IgG4 levels indeed correlate with improved clinical responses. IgG4 antibodies not only block IgE mediated food allergies but also block the reactions of food antigens with other IgG subclasses, reducing inflammatory reactions caused by the other IgG subclasses of antibodies to food antigens.

(Figure 1)In IgG1, IgG2, and IgG3 antigen binding sites are for the same food antigen. In IgG4 the antigen binding sites are for different antigens so that large immune complexes cannot be formed.

In IgG mediated food allergy testing, the goal is to identify foods that are capable of causing inflammation that can trigger a large number of adverse reactions. IgG1, IgG2, and IgG3 all are capable of causing inflammation because these antibodies do not exchange heavy and light chains with other antibodies to form bispecific antibodies. Thus, IgG1, IgG2, and IgG3 antibodies to food antigens can and do form large immune complexes or lattices that fix complement and increase inflammation. The presence of IgG4 antibodies to food antigens indicates the presence of antibodies to foods that will not usually cause inflammation even though high amounts of these antibodies do indicate the presence of immune reactions against food antigens. Testing only for IgG4 antibodies in foods limits the ability of the clinician to determine those foods that are causing significant clinical reactions that are affecting their patients. The importance of measuring other subtypes of IgG antibodies is highlighted in an article by Kemeny et al. (17). They found that IgG1 antibodies to gluten were elevated in all 20 patients with celiac disease but none of the patients had elevated IgG4 antibodies to gluten.

Specimen Requirements

The IgG Food Allergy Test is available as both Serum and Dried Blood Spot.

• Serum: 1 mL of in a gold-topped SST or in a royal blue-topped no additive tube.
• Dried Blood Spot (DBS): Five full circles of dried blood on the protein saver card is required.
• IgG Food Allergy Test w/ Candida (94) + IgE Food Essential Test (12): 3 mL of in a gold-topped SST or in a royal blue-topped no additive tube.

Please note that the elimination of a food prior to sampling will reduce the ability for our laboratory to detect antibodies (allergies) to that food.

Test Collection Instructions 

VIEW A SAMPLE REPORT (USA FOOD)

VIEW A SAMPLE REPORT (ASIAN FOOD)

Clinical usefulness of IgG food allergy testing

Methodology

Immunoglobulin G (IgG) food allergy testing has made vast advancements since the year 2003 when the American Academy of Allergy, Asthma, and Immunology published a statement that "Measurement of specific IgG antibodies to foods is also unproven as a diagnostic tool"(1). Most of the IgG food allergy testing throughout the world is done using the same immunochemical technique. First, soluble food proteins in solution are reacted to a solid phase that chemically binds to a variety of proteins. The use of plastic microtiter trays with one to several hundred wells has become the most common material used as the solid phase. Then these trays are washed, dried, and stored for later use. A sample of diluted is then added to each of the wells. Antibodies of all types in the diluted bind to the specific food molecules that are attached to the plastic wells of the tray.

Next, the plates are washed to remove any nonspecific antibodies in the diluted . At this time, food antibodies from all of the five major immunoglobulin classes called G, A, M, E, and D may be attached to the food antigens on the plate.

The next step confers specificity on the assay. Antisera from sheep, goats, rabbits, or other animals that specifically binds to IgG is added to microtiter wells and only binds to IgG, not to IgA, IgM, IgE, or IgD. This antibody to IgG has previously been modified by the attachment of an enzyme that can be measured conveniently. The amount of enzyme bound to food antigen-IgG complexes on the plate is directly related to how much IgG antibody is attached to a given food. The overall technique is termed Enzyme Linked Immuno Assay or ELISA. If IgG4 is measured, an anti specific for IgG4 only must be used for the final step.