Food-dependent exercise-induced anaphylaxis: a report of two cases and determination of wheat-gamma-gliadin as the presumptive allergen

Water/salt-insoluble wheat proteins have been identified as the most frequent allergenic foodstuffs in patients with food-dependent exercise-induced anaphylaxis (FDEIA) in Japan. However, the specific allergenic proteins in wheat-dependent exercise-induced anaphylaxis have not been well defined. Challenge testing, skin testing and a fluoroenzyme immunoassay were used for diagnosis in two patients suspected by history of having wheat-dependent exercise-induced anaphylaxis. Gel chromatography and IgE immunoblotting followed by N-terminal amino acid sequencing were used to identify the allergenic wheat protein. The challenge test revealed that both patients had FDEIA. The skin tests and the immunoassay results suggested that wheat gluten was the allergen in both patients. Gel chromatography of wheat gluten revealed that the antigens had molecular weights ranging from 40 to 250 kDa. IgE immunoblotting and subsequent N-terminal amino acid sequencing revealed that wheat-gamma-gliadin was the antigen predominantly bound by IgE in the two patients.     

Altered in vitro apoptosis of cultured mast cells prepared from an inbred strain of mice, NC/Kuj

BACKGROUND: An inbred strain of mice, NC, develops dermatitis associated with highly elevated serum IgE and dermal mast cell hyperplasia. OBJECTIVES AND METHODS: To clarify the mechanisms for the dermal mast cell hyperplasia in NC, we prepared bone marrow-derived mast cells (BMMCs) from three strains of mice, NC/Kuj, C57BL/6 and BALB/c, and compare histamine contents, histamine release abilities, adhesive properties and apoptosis of the BMMCs. RESULTS: Compared with BMMCs obtained from C57BL/6 and BALB/c, NC/Kuj BMMC possessed higher histamine content and higher adhesive ability to plastic plates, although histamine release from BMMCs was found to be similar in the three strains. The most intriguing finding is the lack of apoptosis in the BMMCs from NC/Kuj upon growth factor deprivation as determined by DNA ladder formation and loss of membrane phospholipid asymmetry. CONCLUSION: The altered in vitro properties of mast cells in NC/Kuj partially account for an increase of dermal mast cells, which might be involved in the development of skin lesions in NC.     

Pressure challenge test and histopathological inspections for 17 Japanese cases with clinically diagnosed delayed pressure urticaria

Delayed pressure urticaria (DPU) is characterized by deep dermal wheals that appear in response to a local continuous pressure. Although it has been reported to complicate as many as 40% of cases of Caucasian patients with chronic urticaria, no definitive cases of Asian/Japanese patients have been reported in English literature. Here, we identified 17 cases of DPU, among 540 Japanese patients with urticaria (3.1%), based on careful history taking, pressure challenge test and, ideally, skin biopsy. Twelve out of 17 patients (70.5%) who undertook pressure challenge test developed wheal and erythema in the area of pressure 1–12 h later. Six out of 15 patients (40%) were positive for the autologous serum skin test. All cases were complicated with ordinary chronic urticaria, and all specimens of skin biopsies performed for 12 patients showed substantial eosinophil infiltration. All cases were resistant to antihistamines with or without other non-steroidal medications and eventually treated with 0.25–1.5 mg/day of betamethasone. However, 12 of them (70.6%) were able to cease steroid use because of cure or remission. For those cured or in remission, the duration of steroid administration and that from the onset to diagnosis was 11.2 ± 11.0 and 54.8 ± 60.2 months (mean ± SD), respectively. DPU may be identified as a relatively rare complication of Japanese patients with chronic idiopathic urticaria. A proper diagnosis and a small amount of steroid may be beneficial for the treatment of DPU.     

Murine membrane inhibitor of complement which accelerates decay of human C3 convertase

A membrane protein of MW 60,000 was purified from mouse erythrocytes. This protein inhibits generation of mouse complement C3/C5 convertases on antibody-sensitized rabbit erythrocytes, in a haemolytic assay system using guinea-pig serum diluted in EDTA as the source of C3 to C9. This protein also has the capacity to accelerate the decay of human C3 convertase of the classical complement pathway. Antibody to this membrane protein also reacted with peripheral blood mononuclear cells and spleen cells, as observed by fluorescent flow cytometry analysis. Since the reactivity of these cells to the antibody was reduced by treatment with phosphatidyl inositol-specific phospholipase C (PIPLC), it is suggested that the protein is attached to the membrane via a glycophospholipid anchor. Based on these results, we conclude that this membrane protein is a murine homologue of human decay-accelerating factor (DAF).     

Enhancement of fibroblast-dependent mast cell growth in mice by a conditioned medium of keratinocyte-derived squamous cell carcinoma cells

We investigated the increase in mast cell numbers at the sites of inoculation of keratinocyte-derived squamous cell carcinoma cell line (KCMH-1) cells in mice. A significant increase in the number of mast cells was observed at the sites of tumours developed at the sites of inoculation of the KCMH-1 cells. Enhancement of mast cell growth was observed by culturing bone marrow-derived mast cells (BMMC) on NIH/3T3 fibroblast monolayers in the presence of conditioned medium (TCM) obtained from KCMH-1. Activities of known factors for mast cell growth, such as interleukin-3 (IL-3), IL-4, IL-9, IL-10 and stem cell factor (SCF), were not detected in the TCM. Nerve growth factor (NGF) did not induce mast cell growth. Mast cell growth induced by the TCM needed 3T3 fibroblasts. These results suggest that KCMH-1 cells may produce a factor which induces mast cell growth with 3T3 fibroblasts, other than the already known mast cell growth factors. This may be the mechanism of mast cell accumulation at sites of tumours.