Table 2.
Allergy types according to Coombs and Gell, clinical reactions provoked by blinded, placebo-controlled food challenge tests (BPCFC) and causative allergens in the study group with gastrointestinally mediated allergy (GMA)
| Allergy type | Clinical reactions during food challenge | Eliciting allergens |
|---|---|---|
| n = patients | n = patients | |
| Type I allergy | ||
| (Systemic IgE) | ||
| 25 patients | 10 diarrhoea | 7 nuts |
| 18 atopics (72%) median serum IgE | 4 pruritus, vomiting, abdominal pain, tachycardia | 6 egg, wheat |
| 5 milk | ||
| 4 hazelnut, soy flour | ||
| 3 pollen associated fruits | ||
| 2 rye, celery, spice | ||
| 1 fish, maize, oat, barely, rice, peach, carrot, banana, pork | ||
| 198 (84.5 – 405) | ||
| 4 epigastric pain, bloating | ||
| 2 nausea, hypotension, GI- bleeding | ||
| 1 dyspepsia, flatulence, arthralgia, restlessness, fever, urticaria, abdominal colics, | ||
| Type I allergy | 12 diarrhoea | 8 milk |
| (Local IgE) | 10 abdominal pain | 5 nuts, pork, egg, wheat |
| n = 22 | 5 bloating | 3 rice, pollen associated fruits |
| 11 atopics (50%) | 4 colitis | 2 soy flour, maize, celery |
| Median serum IgE | 3 GI-bleeding | 1 fish (salmon), beef, rye, |
| 39 (23 – 77.5) | 2 pruritus, eosinophilia, urticaria | hazelnut, moulds |
| 1 hypotension, dysphagia tachycardia, gastroesophageal reflux, ascites, edema | ||
| Type III allergy (serum immune complexes) | 3 diarrhoea | 4 soy flour |
| 2 bloating, abdominal pain | 2 pork | |
| 1 GI-bleeding, tachycardia, hypotension, nausea | 1 rye, rice | |
| n = 4 | ||
| 2 atopics (50%) | ||
| median serum IgE | ||
| 38.5 (20 – 83) | ||
| Type IV allergy | 6 diarrhoea | 5 rye |
| (Cellular hypersensitivity) | 3 abdominal pain, pruritus | 3 wheat, beef |
| n = 12 | 2 bloating, vomiting, flatulence, hypotension | 2 milk, pork, soy flour, egg, soy bean |
| 5 atopics (41.6%) | ||
| Median serum IgE | ||
| 31 (10 – 57.5) | ||
| 1 tachycardia, flush, GI-bleeding | 1 nuts, chicken, maize, moulds, pollen-associated fruits |
N = patient number, OAS oral allergy syndrome.
Atopy status was defined as positive, when history or clinical manifestation of the patient gave evidence for seborrheic dermatitis, atopic dermatitis or eczema, asthma bronchiale and/or allergic rhino - conjunctivitis.
For definition of the allergy type, the most dominant immunological signs were chosen to classify the ongoing allergic mechanisms in this population of patients with manifest gastrointestinally mediated allergy. However, some patients displayed symptoms that suggested more than one definitive type of allergy. Type I allergy (systemic IgE sensitization) was recognised when positive skin and/or antigen specific IgE levels were present in serum (>0.35 U/ml), type I allergy (local IgE sensitization) was diagnosed when intestinal lavage fluid contained elevated food antigen-specific levels of IgE (>0.35 U/mg protein) [11,23].
Type III allergy was found in 4 patients who showed formation of either IgA, IgM and/or IgE immune complexes during or after allergen application by blinded food challenge, while pre-challenge serum immune complexes were normal during potato-rice diet.
Type IV allergy was diagnosed or suspected in 7 patients and 5 with mixed allergy types who showed markedly increased production of serum TNF levels during or after food challenge, while pre-challenge TNF levels were normal during potato-rice diet. Additionally, in one patient type IV allergy was considered because of a positive antigen-specific lymphocyte proliferation test corresponding to the results of BPCFC.