Food Allergy Testing

Consideration of food allergy testing is a critical component of any comprehensive approach to ill health or disease prevention.

At Meridian Valley Laboratory our food allergy testing includes:

• High quality, standardized food antigens from licensed American manufactures
• State-of-the-art Enzyme-linked Immunosorbent Assay technique (ELISA)
• User-friendly results
• Quick turnaround time
• Automated, reproducible laboratory processes that ensure efficiency from the time the sample is received to the time the result is reported
• Consistent automation and tracking for the most accurate assay results
• Individualized elimination and rotation diet guidelines
• Easy pre-paid specimen shipping by UPS

It is estimated that that up to 12 million Americans have food allergies. A food allergy is an abnormal response by the immune system to a food trigger. Development of food allergies is dependent on a number of factors including timing of exposure to the allergenic food, frequency of consuming the allergenic food, and the integrity of the gastrointestinal system. Food allergies are implicated in a wide variety of conditions, some of which include migraine, depression, inflammatory bowel disease, chronic ear infections, eczema, psoriasis, recurrent infections, and weight gain.

Allergy Testing For IgE Immediate Onset Food Allergies

Food allergies are classified as immediate (IgE mediated) and delayed (IgG mediated). IgE production occurs rapidly with the ingestion or inhalation of an allergen and is referred to as immediate hypersensitivity reaction, and is characterized by the release of histamine upon exposure to the allergen. IgE mediated hypersensitivities can be life threatening, and occur in approximately 20% of the population. IgE is produced in response to an allergen/antigen and binds to the mast cells and basophils. This triggers release of histamine and production of other inflammatory mediators, resulting in an early allergic reaction phase that appears within minutes of exposure to an allergen/antigen. Late phase reactions result in further histamine release (within a few hours).

Food Allergy Testing For IgG Delayed Onset Food Allergies

IgG antibodies are produced for several hours or days after exposure to an allergen and are called Type III delayed hypersensitivity reactions. Immune complexes activate a portion of the immune system known as complement and cytokins. This process takes anywhere from several hours to several days, which is why hypersensitivity reactions are delayed. Depending on which tissues are involved, deposition of IgG-Antigen complexes may result in a variety of health concerns such as joint pain, chronic headaches, hypertension, fatigue, eczema, and psoriasis. IgG allergies are difficult to diagnose because reactions do not occur until hours or days after ingestion of an allergen. This is why it is difficult to determine which foods are the causative agents.

The Gluten/Gliadan Connection

Type IV reactions are cell-mediated. Killer T-cells become cytotoxic when activated by an antigen. These cytotoxic cells are capable of killing bacteria, viruses, tumor cells, or other target cells. This reaction is involved in very severe food reactions to the glidian protein in grains. An overload of IgG antibody-allergen complexes can cause damage to the gut mucosal lining and cause protein wasting in conditions such as Celiac disease, Ulcerative Colitis, Crohn’s disease, and Leaky Gut. The leaky gut then allows more antibody-allergen complexes to escape into tissues, which provokes more food allergies.

Method

Food allergy testing using serum measures IgG and IgE and bloodspot tests measure total IgG through ELISA/EIA, which includes IgG4. Serum is added to a 96-well plate containing different food antigens and then evaluated for classic antigen/antibody interactions. Accurate testing requires the patient to eat a wide range of foods within 3 weeks of assessment for IgG exposure to be present. The test provides a report of whether the levels of antibody to the various foods suggest that each one is “safe” to eat, best to eat in moderation, or to avoid entirely.

BloodSpot

The newest development in food allergy testing is the Food Safe Allergy Test, which requires only a small amount of blood for testing of 95 food antigens. This allows the patient to do the test at home or for the doctor to do in-office without a venipuncture. The finger is pricked with a lancet and then drops of blood are placed on a blood spot collection card. The card is air-dried and returned to the laboratory for assessment. IgG results are ranked according to their concentrations, and then reported as safe, moderately safe, or avoid. These results can then be used to design therapeutic elimination or rotation diets.

Benefit

Allergy testing provides a quick and easy way for practitioners to discover potential causes of allergic reactions and allergy related disease. The test reports include reference ranges along with a suggested rotation diet. When compliance is high, patients report improvement in symptoms, elimination of long-standing health issues, and, in general, a more satisfying quality of life.