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It is well-known that intolerance to certain foods may disturb the digestive system, cause skin problems and hormonal imbalance. Cereals are among the most common food to induce hypersensitivity reaction. The most common antigen is wheat followed by barley and rye.
There are four types of proteins present in cereals defined as albumins, globulins, prolamins and glutelins. 30-60% of the protein content consists of prolamin. The name prolamin refers to its high content of proline and glutamine. 50% of the protein in oat, barley and wheat consists of those amino acids.
Food allergies are either immediate ones, caused by IgE-mediated mast cell degranulation and histamine release. The second type is cell-mediated reactions with food-specific T cells as key players. It is postulated that pepsin in the stomach may cause digestion of IgE- inducing epitopes of food proteins and such digested allergens might induce IgE-independent T cell inflammation.
In a Swedish study (unpublished) 20 patients with colon irritable, eczema and premenstrual syndrome, often combined with psychological problems, before and after elimination of cereals from their diet. Almost all of the patients noticed a positive effect following the elimination of gluten-containing meals, the majority immediately or within a week. Seven of the patients were tested for tissue transglutaminase but had none had positive results. Thus, serum tests seemed to have limited diagnostic value.
In cooperation with the Swiss allergologist Dr Paul Corthay, and the MELISA® laboratory in Geneva, MELISA Medica Foundation conducted a study on the use of MELISA® for the diagnosis of gluten allergy in patients attending allergy clinics near Geneva. Most of the patients suffered from various allergies but psychological and gastrointestinal problems often complicated the clinical picture.
In addition to detailed anamnesis and testing with MELISA®, prick test with food extracts and serum transglutaminase IgG and IgA were also determined.
In preliminary experiments, gluten extract (Sigma) did not induce significant lymphocyte proliferation in non-allergic healthy subjects.
During first the 6 months of 2006, 136 patients were tested to gluten and dental metals by the MELISA® test. Forty-four patients were found gluten-positive (32%) while serum tests were only rarely positive. Gluten-positive patients responded significantly more often to dental metals as compared to gluten-negative patients (P< 0,001 for Hg, Sn, Ti, Al, and P< 0,05 for Pb, MeHg, Ni, Thimerosal).
Skin prick tests depended on the individual variability (the quality of the skin) and varied largely.
Gluten-specific MELISA® seems to be clinically relevant as shown is some case-reports. After strict avoidance of gluten-containing foods, gluten-positive lymphocyte reactivity returned to normal and patient’s health improved.
In conclusion, gluten reactivity seems to be common in patients with allergic diseases and the simultaneous testing of gluten together with metal testing seems to be beneficial to the patient.
Currently, gluten testing with MELISA® is only performed in the laboratories in Belgium and Switzerland. |
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