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. Candida problems 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
The Benefits of Testing
- Helps determine if food reactions are contributing to physical or mental symptoms
- Removal of highly reactive foods from the diet is a non-invasive, food-based therapy that often mitigates a patient's symptoms
- Research and clinical studies suggest food allergies identified by IgG testing can be a major contributing factor in many chronic health conditions
- Food rotation and elimination diets can reduce stress on the immune system, lower gut inflammation, resolve food cravings, and reduce the potential for eating disorders
"I believe the Great Plains IgG Food Allergy Test is a phenomenal tool that I have implemented in my practice on a daily basis to help treat patients for a wide variety of symptoms like headaches, IBS, fatigue, abdominal pain, dermatitis, hair loss, joint pain, acne, thyroid disorders, and vitamin deficiencies. I believe I am a better physician due to this testing transforming my ability to properly diagnose and treat patients effectively."–Bridget, M.D.
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.
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.
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.
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.
The clinical usefulness of IgG testing in an array of illnesses is illustrated in an early article published by an otolaryngologist who reported that the majority of his patients had substantial health improvements after an elimination of foods positive by IgG food allergy tests (2). The overall results demonstrated a 71% success rate for all symptoms achieving at least a 75% improvement level. Of particular interest was the group of patients with chronic, disabling symptoms, unresponsive to other intensive treatments. Whereas 70% obtained 75% or more improvement, 20% of these patients obtained 100% relief. Symptoms most commonly improved 75%-100% on the elimination diets included asthma, coughing, ringing in the ears, chronic fatigue, all types of headaches, gas, bloating, diarrhea, skin rash and itching, and nasal congestion. The most common IgG food allergies were cow's milk, garlic, mustard, egg yolk, tea, and chocolate.
The usefulness of IgG food allergy to design customized elimination diets has now been documented in scientific studies. Irritable bowel syndrome (IBS) is a common, costly, and potentially disabling gastrointestinal (GI) disorder characterized by abdominal pain/discomfort with altered bowel habits (e.g., diarrhea, constipation). The major symptoms of IBS are abnormality of bowel movement, reduction in bowel sensitivity thresholds, and psychological abnormality. Many IBS patients have psychological symptoms including depression, anxiety, tension, insomnia, frustration, hypochondria, and psychosocial factors (3).
Atkinson et al evaluated a total of 150 outpatients with irritable bowel syndrome (IBS) who were randomized to receive, for three months, either a diet excluding all foods to which they had raised IgG antibodies (ELISA test) or a sham diet excluding the same number of foods but not those to which they had antibodies (4). Patients on the diet dictated by IgG testing had significantly less symptoms than those on the sham diet after 120 days on the diets. Patients who adhered closely to the diet had a marked improvement in symptoms while those with moderate or low adherence to the IgG test dictated diets had poorer response.
Similar results were also obtained by Drisko et al (5). They used both elimination diet and probiotic treatment in an open label study of 20 patients with irritable bowel syndrome diagnosed at a medical school gastroenterology department. The most frequent positive serologic IgG antigen-antibody complexes found on the food IgG tests were: baker's yeast, 17 out of 20 (85%); onion mix, 13 out of 20 (65%); pork, 12 out of 20 (60%); peanut 12 out of 20 (60%); corn, 11 out of 20 (55%);wheat, 10 out of 20 (50%); soybean, 10 (50%); carrot, 9 out of 20 (45%); cheddar cheese, 8 out of 20 (40%); egg white, 8 out of 20 (40%). Only 5 out of 20 reacted by IgG antibody production to dairy; however the majority of patients reported eliminating dairy prior to trial enrollment presumably clearing antigen-antibody complexes prior to testing. Significant improvements were seen in stool frequency, pain, and IBS quality of life scores. Imbalances of beneficial flora and dysbiotic flora were identified in 100% of subjects by comprehensive stool analysis. There was a trend to improvement of beneficial flora after treatment but no change in dysbiotic flora. The one-year follow up demonstrated significant continued adherence to the food rotation diet, minimal symptomatic problems with IBS, and perception of control over IBS. The continued use of probiotics was considered less helpful.
IgG food allergy testing was also proved effective in the gastrointestinal disorder Crohn's disease. Bentz et al found that an elimination diet dictated by IgG food allergy testing resulted in a marked reduction of stool frequency in a double blind cross-over study in which the IgG-dictated diet was compared to a sham diet in 40 patients with Crohn's disease (6). IgG food allergies were significantly elevated compared to normal controls. Cheese and baker's yeast (Saccharomyces cerevisiae) allergies were extremely common with rates of 83% and 84% respectively.
Main et al, focusing on the baker's yeast allergy, also found extremely high prevalence of IgG allergy in patients with Crohn's disease(7). Titers of both IgG and IgA to S. cerevisiae in the patients with Crohn's disease were significantly higher than those in the controls. In contrast, antibody titers in the patients with ulcerative colitis were not significantly different from those in the controls. Among the patients with Crohn's disease there was no significant difference in antibody titers between patients with disease of the small or large bowel. Since IgG antibodies to S. cerevisiae cross react with Candida albicans (8), Candida species colonization might be a trigger for the development of Crohn's disease.
IgG food sensitivities to wheat, gluten, gliadin, rye, and barley are prevalent in the gastrointestinal disorder celiac disease. Virtually all patients with celiac disease have elevated IgG antibodies to gliadin if they currently have wheat or related grains in their diet. The diagnosis of celiac disease is confirmed by the presence of flattened mucosa with a lack of villi when a biopsy sample of the small intestine is examined microscopically. Another confirmation test with equal sensitivity is a blood test for IgA transglutaminase antibodies. The antibody confirmation test is equal in accuracy to the biopsy test with the exception that individuals with IgA deficiency may have false negative results. However, it is estimated that only 1% of people with elevated IgG antibodies to gliadin and other grains related to wheat have celiac disease. If the individual is negative for the confirmation tests for celiac disease, many patients are frequently erroneously advised that that have no problem with wheat.
Hadjivassiliou et al argued that it is a significant clinical error to classify wheat allergy through the filter of celiac disease and that celiac disease is a subtype of wheat sensitivity (9. Many of their patients with wheat allergy but celiac disease negative had remission of severe neurological illnesses when they adopted a gluten free diet and expressed that in these patients the gluten molecule causes an autoimmune reaction in the brain rather than in the intestinal tract, likely against the Purkinje cells that are predominant in the cerebellum.
A wide range of additional studies has proven the clinical value of IgG antibodies in autism (10), bipolar depression (11), schizophrenia (12), migraine headaches (13), asthma (14), and obesity (15).
Irritable bowel disease
W Atkinson, et al Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial.Gut 2004;53:1459-1464
Bentz S,Clinical relevance of IgG antibodies against food antigens in Crohn's disease: a
Huber A,et al Int Arch Allergy Immunol. 1998 Jan; 115(1):67-72. Diet restriction in migraine, based on IgG against foods: a clinical double-blind, randomised, cross-over trial.
Severance EG et al Immune activation by casein dietary antigens in bipolar disorder. Bipolar Disord 2010: 12: 834–842
Severance EG, et al Subunit and whole molecule specificity of the anti-bovine casein immune response
Wilders-Truschnig M et al. IgG Antibodies Against Food Antigens are Correlated with Infl ammation and Intima Media Thickness in Obese Juveniles. Exp Clin Endocrinol Diabetes DOI 10.1055/s-2007-993165
Tahmeed Ahmed; et al Circulating antibodies to common food antigens in Japanese children with IDDM
Vladimir Trajkovski et al Higher Plasma Concentration of Food-Specific Antibodies in Persons With Autistic Disorder in Comparison to Their Siblings.
O'Farrelly, C., Price, R., McGillivray, A.J. and Fernandes, L. (1989), IgA rheumatoid factor and
- Statement of the AAAAI Work Group Report: Current Approach to the Diagnosis and Management of Adverse Reactions to Foods, October 2003. http://www.aaaai.org/ask-the-expert/usefulness-of-measurements-of-IgG-antibody.aspx (Accessed October 27,2013).
- Dixon H, Treatment of delayed food allergy based on specific immunoglobulin G RAST testing relief. Otoloryngol Head Neck Surg 2000;123:48-54.
- Nagisa Sugaya N and Nomura S, Relationship between cognitive appraisals of symptoms and negative mood for subtypes of irritable bowel syndrome. BioPsychoSocial Medicine 2008;2:9-14
- Atkinson, W et al. Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial Gut 2004;53:1459-1464
- Drisko J, Bischoff B, Hall M, McCallum R, Treating Irritable Bowel Syndrome with a Food Elimination Diet Followed by Food Challenge and Probiotics. Journal of the American College of Nutrition 2006; 25: 514–522
- Bentz S, et al. Clinical relevance of IgG antibodies against food antigens in Crohn's disease: a double-blind cross-over diet intervention study. Digestion. 2010;81:252-64.
- Janice Main, Hamish McKenzie, Grant R Yeaman, Michael A Kerr, Deborah Robson, Christopher R Pennington, David Parratt Antibody to Saccharomyces cerevisiae (bakers' yeast) in Crohn's disease BMJ 1988;297:1105-1106
- Thomas Schaffer, Stefan Mueller, , Beatrice Flogerzi, , Beatrice Seibold-Schmid,Alain M. Schoepfer, and Frank Seibold Anti-Saccharomyces cerevisiae Mannan Antibodies (ASCA) of Crohn's Patients Crossreact with Mannan from Other Yeast Strains, and Murine ASCA IgM Can Be Experimentally Induced with Candida albicans Inflamm Bowel Dis 2007;13:1339 –1346
- M Hadjivassiliou, R A Grünewald, G A B Davies-Jones Gluten sensitivity as a neurological illness. Neurol Neurosurg Psychiatry 2002;72:560–563
- Vladimir T et al Higher Plasma Concentration of Food-Specific Antibodies in Persons With Autistic Disorder in Comparison to Their Siblings. Focus Autism Other Dev Disabl 2008; 23: 176-185
- Severance EG et al Immune activation by casein dietary antigens in bipolar disorder. Bipolar Disord 2010;12: 834–842
- Severance EG, et al Subunit and whole molecule specificity of the anti-bovine casein immune response in recent onset psychosis and schizophrenia. Schizophr Res. 2010;118:240-7.
- Alpay et. al. (2010). Diet restriction in migraine, based on IgG against foods: A clinical double-blind, randomised, cross-over trial. Cephalalgia. 2010 July; 30(7): 829–837.doi: 10.1177/0333102410361404.
- Vance G. et al. Ovalbumin specific immunoglobulin G and subclass responses through the first five years of life in relation to duration of sensitization and the development of asthma. Clia Exp Allergy 2004;34:1452-1459
- Wilders-Truschnig M et al. IgG Antibodies Against Food Antigens are Correlated with Inflammation and Intima Media Thickness in Obese Juveniles. Exp Clin Endocrinol Diabetes 2008;116:241-5.
- Marijn van der Neut Kolfschoten, et al Anti-Inflammatory Activity of Human IgG4 Antibodies by Dynamic Fab Arm Exchange. Science 2007;317:1554-1555
- Kemeny DM, et al Sub-class of IgG in allergic disease. I. IgG sub-class antibodies in immediate and non-immediate food allergy. Clin Allergy. 1986; 16:571-81.
- Volpi, Nicola and Maccari, Francesca(2009) ' IgG Responses to Food Antigens in the Italian Population Evaluated by Highly Sensitive and Specific ELISA Test', Journal of Immunoassay and Immunochemistry, 30: 51 — 69
- Stapel SO, Testing for IgG4 against foods is not recommended as a diagnostic tool: EAACI Task Force Report.Allergy. 2008 Jul;63(7):793-6. Epub 2008 May 16.
The IgG Food Allergy Test is available in two options to accomodate both Western and Eastern diets.
- Baker's Yeast (Saccharomyces cerevisiae)
- Brewer's Yeast (Saccharomyces cerevisiae)
- Candida albicans
- Cane Sugar
- Cod fish
- Egg White
- Egg Yolk
- Garbanzo Beans
- Goat's Milk Cheese
- Green Bean
- Green Pepper
- Kidney Bean
- Lima bean
- Pinto Bean
- Plum (Prune)
- Sweet Potato
- Wheat Gluten
- Adzuki Bean
- Bamboo Shoot
- Black Pepper
- Burdock (Gobo)
- Candida albicans
- Curry Powder
- Green Bean
- Green Pepper
- Green Tea
- Jack Mackerel
- Kombu (Kelp)
- Laver (Nori)
- Lotus Root
- Oolong Tea
- Pacific Saury
- Red Pepper
- Seaweed (Wakame)
- Sweet Potato
- Vanilla Bean
- Wheat Gluten
- Yeast (Brewer's)
- Irritable bowel syndrome (IBS)
- Bipolar Depression
- Migraine headaches