IgE binding to soluble and insoluble wheat flour proteins in atopic and non-atopic patients suffering from gastrointestinal symptoms after wheat ingestion.

BACKGROUND: The involvement of IgE-mediated hypersensitivity reactions in the genesis of gastrointestinal symptoms after ingestion of foods containing wheat has been rarely reported. OBJECTIVE: To detect IgE specifically binding to wheat proteins in the sera of atopic and non-atopic patients suffering from gastrointestinal symptoms after ingestion of wheat and to evaluate the reliability of skin prick test and CAP in the diagnosis of food allergy to wheat. METHODS: The sera of patients (10 atopic and 10 non-atopic) previously diagnosed as suffering from irritable bowel syndrome and complaining of symptoms after wheat ingestion were analysed by immunoblotting for IgE binding to water/salt-soluble and insoluble wheat flour proteins. RESULTS: All the atopic patients and only one of the non-atopic patients were positive to wheat CAP. For the patients tested, skin prick test was positive for all the atopic patients and for only one of the non-atopic patients. However, immunoblotting experiments showed the presence of specific IgE to wheat proteins in all the patients. Ten out of 11 of the wheat CAP-positive patients had IgE binding to a soluble 16-kDa band, but the same band was recognized, in a slighter way, by only two out of nine of the wheat CAP-negative patients. Moreover, although almost all of the patients were negative in CAP testing with gluten, 19 out of 20 recognized protein bands belonging to the prolamin fraction. CONCLUSIONS: For the atopic patients the positivity to skin prick test and CAP to wheat was in accordance with the immunoblotting results and a food allergy to wheat could be diagnosed. In these patients a major allergen was a 16-kDa band corresponding to members of the cereal alpha-amylase/trypsin inhibitors protein family, the major allergens involved in baker's asthma. In the non-atopic patients the positive immunoblotting results contrasted with the responses of the allergologic tests, indicating that the allergenic wheat protein preparations currently used are of limited value in detecting specific IgE to wheat and that the fraction of irritable bowel syndrome (IBS) patients with food allergy may be larger than believed.

IgE binding to almond proteins in two CAP-FEIA-negative patients with allergic symptoms to almond as compared to three CAP-FEIA-false-positive subjects.

BACKGROUND: Allergy to almonds has been frequently reported, but data on the identification of the almond allergens, as well as on the reliability of the methods for in vitro detection of specific IgE for these allergens, are scant. This study aimed to identify the almond allergens and to evaluate the reliability of the CAP-FEIA as the standard system for detection of almond-specific IgE with clinical significance. METHODS: Immunoblotting performed with an almond-protein extract was carried out on the sera of five patients who had previously been tested by the CAP-FEIA system; two of these patients had tested negative with the CAP-FEIA system but suffered life-threatening laryngeal edema after eating almonds, whereas the other three subjects, who had tested positive with CAP-FEIA, did not present any symptoms subsequent to almond ingestion. RESULTS: The sera of the two symptomatic CAP-FEIA-negative patients had IgE that bound only to a 37-kDa protein in immunoblotting. On the contrary, the sera of the three asymptomatic subjects all showed IgE binding to two almond proteins of 62 and 50 kDa, corresponding to the glycosylated components of the extract. CONCLUSIONS: The results here presented suggest that, at least for the examined subjects, the positivity to almond, as measured with a standard laboratory method, is due to the presence of the 62/50-kDa glycoproteins with little or no immunologic significance, and not to the binding to the 37-kDa polypeptide, which appears to be a true almond allergen.

Biological effects of contaminated silicon carbide particles from a workstation in a plant producing abrasives.

A sample of silicon carbide dust taken in the field from a plant producing abrasives was studied in vitro. The SiC particles (part unmilled and part milled) were able to disturb the structure of erythrocyte membranes and to lead to blood red-cell lysis; they also either interfered with complement and activated the alternate pathway, or interacted with biological media and polymorphonuclear leucocyte membranes, thus eliciting reactive oxygen species production. These in vitro properties were detected both in original large particles and unmilled particles, over 40% of which were of respirable size. The ability of these SiC particles to produce complement activation in vitro lends support to the previous hypothesis, that the radiographic opacities found in two workers employed in the same area of the plant from which the dust tested was taken are due to a reaction by pulmonary interstitial structures to SiC particle inhalation. It is speculated that SiC particles could act like asbestos, the ability of which to activate complement through the alternate pathway is considered to be one of the mechanisms by which the initial asbestotic lesions and subsequent fibrotic inflammatory infiltrates are generated in the lung.

Longitudinal study of alveolitis in hypersensitivity pneumonitis patients: an immunologic evaluation.

Cells recovered from bronchoalveolar lavage were studied, both from a phenotypic and functional point of view, in 18 patients with hypersensitivity pneumonitis (HP) during a prolonged follow-up. A series of monoclonal antibodies against different lymphocyte subpopulations, including T cells, T cell subsets, and natural killer (NK) cells have been used. In some cases, an immunohistologic analysis of lung tissue sections has also been performed. The NK activity has been evaluated with regard to the in vitro function. At the time of the first evaluation, a high number of CD8+ cells with an imbalance of CD4/CD8 ratio had been demonstrated in patients with HP. Consecutive bronchoalveolar lavage evaluations demonstrated a persistent increase of CD8+ cells and a reversal of CD4/CD8 ratio in patients who continued to be regularly exposed to etiologic antigens at work (W+). In the same cases, a persistent increase of NK cells was demonstrated. Cytotoxic cells demonstrated a persistently enhanced in vitro lytic function during the follow-up, even though there appeared to be a trend toward the normal range. Patients who continued to live in agricultural environments but were not further exposed to specific antigens at work (W-) exhibited a recovery of CD4+ cells, a decrease in CD8+ cells, and an increase of CD4/CD8 ratio to the normal range 6 months after the first observation. Immunohistologic analysis, performed at the time of the first evaluation, demonstrated a diffuse infiltration of lung parenchyma by CD8+ cells, both in W+ and W- patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral blood NK cells in patients with extrinsic allergic alveolitis: phenotype and function.

Peripheral blood mononuclear cells obtained from patients with extrinsic allergic alveolitis were tested with a series of monoclonal antibodies against natural killer cells, including HNK-1, NK-15, Ab8.28, OKM1 reagents. An NK in vitro functional evaluation of these cells was associated to the phenotypic analysis. Our data demonstrated an increase, with respect to controls, of the percentage and absolute number of HNK-1 positive cells in the blood of these patients. This increase was consistent with an enhanced cytotoxic in vitro activity. These findings provide evidence that in patients with extrinsic allergic alveolitis, the exposition to antigenic stimuli triggers the NK system. Possible immunopathogenetic mechanisms, especially in comparison with other interstitial lung disorders, are discussed.

Study of immunological parameters in farmer's lung.

A cross-sectional epidemiological study was carried out on 2932 farmers (response rate 92%) living in Northern Italy. A questionnaire on respiratory symptoms was supplied, chest X-ray taken and simple spirometry tests made. Thirty-nine subjects reported attacks of breathlessness associated with fever after exposure to mouldy hay; thirty-six had a clinical history of farmer's lung and X-ray and/or respiratory function changes indicative of chronic farmer's lung; 113 were classified as having bronchial asthma. These 118 subjects and a random sample of 131 non-symptomatic subjects were examined by intracutaneous skin tests and double diffusion precipitation tests with antigens associated with farmer's lung. All sera positive by precipitation were examined by immunoelectrophoresis, counterimmunoelectrophoresis, and C1q binding test, and Bovine conglutinin test in solid phase for the detection of circulating immunocomplexes. 27.8% cases of chronic farmer's lung, 4.4% of cases of bronchial asthma and 2.3% of non-symptomatic subjects showed precipitating antibodies against farmer's lung antigens. Of the precipitin-positive subjects, the majority had precipitating antibodies against Micropolyspora faeni. No differences in immunoelectrophoregrams in number and pattern of precipitation arcs for M. faeni were found between chronic farmer's lung and bronchial asthma subjects. Circulating immune complexes were present in 50% of chronic farmer's lung patients, 40% of those with bronchial asthma and 33.3% of non-symptomatic subjects. Three farmer's lung subjects (9.3%) showed immediate skin-test reactions to rural environmental allergens.

Polyvinyl chloride pneumoconiosis: epidemiological study of exposed workers.

Among 1216 workers who were employed in a polyvinyl chloride production factory and who had had no previous dust exposure elsewhere, 20 cases of pneumoconiosis were found. Chest x-ray abnormalities were characterized by limited profusion, irregular type and low gravity. All 20 workers had been exposed to high PVC dust levels. The chest x-ray changes were observed after a minimum exposure of five years and, in a small percentage of cases, were associated with slight restrictive respiratory function impairments. Moreover, in the whole group of workers 388 cases (31.9%) were found with non-specific x-ray abnormalities mainly related to age and smoking.

[Prevalence of penumoconiosis in a steel-plant (author's transl)]. / Distribuzione della pneumoconiosi in una acciaieria

Chest X-rays of 483 steel workers employed in the same factory were examined by the authors and classified according to the ILO U/C 1971 classification for pneumoconiosis. The prevalence of pneumoconiosis was found to be 8.4%. The majority of the positive cases were detected among the furnace workers and then among presse and rolling-mill workers. Only one positive case was found among the workers of the other foremen. It is stated that the furnace is the main source of pollution and that the lack of protective systems spreads the risk also to the surrounding working sites. No significant differences were found as for the opacity features.