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C Vallon

Publications and source records attributed to C Vallon.

At least 19 recordsLinked to original sources
PubMed1998

Analysis of anti-IgE and allergen induced human basophil activation by flow cytometry. Comparison with histamine release.

OBJECTIVE AND DESIGN: On the basis of flow cytometric methods previously described for the analysis of human basophil activation, we present here a bi-color anti-IgE FITC, anti CD63 PE method and the correlation with histamine release. MATERIALS AND SUBJECTS: Subjects allergic to grass pollen were selected by their clinical history, skin tests and specific IgE. METHODS: Basophils gated in the lymphocyte region of the side scatter (SSC)/forward scatter (FSC) pattern were selected by their high IgE epitope density. Percentage of cells expressing CD63 marker, upregulated on activated basophil membrane, was calculated by the cytometer. Histamine released into the supernatants was measured by RIA. RESULTS: In these conditions, flow cytometric analysis of blood leukocytes showed that the selected cells had the phenotype CD14-, CD19-, CD45+, IgE++ and CD63- or + which is related to human basophil phenotype, the isotype controls being negative. The use of an anti-CD41 FITC antibody also showed the presence of aggregated platelets on the basophil membrane, CD63 antigen being, however, expressed by basophils themselves and not by platelets. Moreover, no statistical difference was observed between histamine release and flow cytometry after passive sensitization of blood donor leukocytes. CONCLUSION: Flow cytometry, as a popular method often used in the immunology and haematology departments of clinical laboratories may represent a new alternative for allergy diagnosis and basophil pharmacology.

Allergens↗
PubMed1997

[Bioclinical interest in the assay of leukotrienes in four cases of sensitization to trophallergens].

New cellular tests as flow cytometry and leukotriene release having been set up for allergy diagnosis, we checked the reliability of the LTC4 release test for 4 patients sensitized to wheat flour, oyster and lobster and to anise. Food allergy diagnosis was based on the clinical history, skin tests (pricks and IDR) and specific IgE. After allergen stimulation, LTC4 released was determined by an RIA method using a monoclonal antibody. The allergen extracts used for skin tests and LTC4 release having the same origin, LTC4 release test showed a good correlation with the clinical history whereas specific IgE determinations were less sensitive. Skin tests were negative in the cases.

Adult↗
PubMed1996

[Importance of the leukotriene C4 liberation test for the diagnosis of drug allergy (preliminary results)].

Pharmacological or immunological activation of human basophil induces the expression of membrane markers such as CD63 and the release of histamine and leukotriene C4 (LTC4). LTC4 release test has the advantages of a cellular test which is obviously closer to the physio-pathological reaction than the direct determination of circulating antibodies. Moreover, the determination of a newly formed mediator eliminates the spontaneous release of mediator by simple cellular damage. We present here, after having controlled the reliability of the method for aero-allergens, preliminary results of LTC4 release obtained for haptens (ampicillin, methylprednisolone and acetylsalicylic acid) which are in favour of the use of this method in the complex field of drug allergy diagnosis.

Adult↗
PubMed1995

[Allergy and professional exposure to sulfur compounds: questions posed].

We present here four cases of respiratory diseases which may be due to the exposition or to the handling of sulfur derivatives due to their professional activity. The responsibility of these compounds stands on the clinical history, biological cellular tests and for one of them on the evolution under a metabisulfite-free diet and a positive oral provocation test at 5 mg. The present economical crisis makes the patient-clinician relationship difficult, due to patients' wishing to hide their pathologies or their professional activities.

Adult↗
PubMed1994

[Demonstration of sulfite-group-specific IgE in patients with intolerance to preservatives].

On the basis of the selection of a population of patients intolerant to sulfites by the clinical history, a simple blind oral provocation test and a basophil activation test, we explored the basophil activation reaction induced by sulfites after passive sensitisation of blood donors basophils. We demonstrated that the percentages of activation obtained with a non covalent reagent (MBS-HSA), a covalent reagent (sulfonyl-HSA) and the optimal concentration of an anti-IgE were not significantly different. Human basophil activation was negativated by heating the transferred sera and by competition with a monoclonal human IgE. We also observed mediator release (histamine and LTC4) with a low frequency, histamine release being strictly related to the carrier protein concentration. In two cases, sulfite specific IgE were detected by ELISA. These results are in favour of the specificity and the IgE dependent nature of basophil activation induced by sulfites.

Antibody Specificity↗
PubMed1994

[Analysis of membrane expression of the CD63 human basophil activation marker. Applications to allergologic diagnosis].

On the basis of the CD 63 bi-modal expression on the membrane of activated basophils, we set up a flow cytometric method for the analysis of human basophils activation by an anti-IgE and anti-CD 63 double labelling. We demonstrated that the statistical characteristics of the percentages of activation obtained by an anti-IgE stimulation allowed the use of this method for pharmacological studies. The percentages of activation were of the same order of magnitude than those obtained by histamine release. CD 63 expression was also observed for a low affinity allergen such as the sulfonyl-HSA conjugate used for sulfites hypersensibility diagnosis, healthy donors being negative. This method, which can be automatized may represent an interesting candidate in the field of hapten hypersensitivity which lacks of reliable diagnostical methods.

Alcian Blue↗
PubMed1994

[Asthma by proxy (to latex of a condom). General review based on an observation].

The AIDS progress in the world has led to a considerable increase in the request of medical gloves but also of condoms. At the same time latex hypersensitivity has a growing effect upon our allergology consultations; although the contact dermatitis and urticaria to condoms are frequent, asthma remains very rare. We report one case of condom nocturnal asthma in a patient also presenting a food allergy to sunflower with cross-reactivity to umbelliferae. The different steps of a latex allergy diagnosis are criticized, the populations at risk are mentioned. Nowadays, no standardized allergen exist, therefore we must put the stress on the prevention. Latex hypersensitivity raises an emergency public health issue.

Adult↗
PubMed1992

[A familial case of metabisulfite intolerance. Clinical and pharmacological study].

Within a context of a familial case of severe respiratory signs, with intolerance of sulfites and aspirin, we decided to study the clinical reliability of "in vitro" activation of human basophils in the presence of sulfites. Positivity of these tests for the three patients in the study (60, 73, and 66%) is confirmed by passive sensitization of donor basophils, which was destroyed when the serum was heated. This argument in favour of IgE dependence was strengthened by observation of an "in vitro" desensitization by an anti-IgE and not by an anti-IgG. These "in vitro" data are in agreement with the clinical history, daily routine of the patient, skin tests and where done, oral provocation tests.

Adult↗
PubMed1989

[Lipid pneumopathy caused by occupational exposure to cutting oil].

This is a case report of a diffuse interstitial pneumonia which developed rapidly in a 45-year-old patient who was occupationally exposed to regular inhalations of motor oil spray. The diagnosis of lipid pneumonia was based on a lung biopsy carried out by thoracoscopy. The biochemical analysis of the lipid extracted from the alveolar lavage and of the pleural liquid showed the presence of hydrocarbons, which were analogous to those found in motor oil and the strippings that were used. The subsequent progress without treatment after removal from the risk showed a partial regression of the radiological abnormalities. The incidence of occupational pneumonia to mineral oils is relatively low when the frequency of exposure is taken into account: objective data on the extent and the nature of exposure are often incomplete in published observations. The occurrence of respiratory symptoms or radiological changes in exposed subjects requires, nevertheless, a search for a possible lipid pneumonia. The diagnosis rests on a biochemical and cytological analysis of the alveolar liquid and on a lung biopsy.

Biopsy↗