[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.

[Diagnosis of delayed type hypersensitivity to Candida albicans. Evaluation of lymphocyte activation by flow cytometry (171 observations)]

Abnormal delayed-type hypersensitivy to Candida albicans, since it results in an excessive reaction of the immune system, is very difficult to diagnose. This study shows that the syndromic reaction observed after intradermal injection of an extract of Candida albicans, in patients suspected of abnormal delayed-type hypersensitivy to this antigen, is associated with the presence of specific circulating T cells, detectable through cell culture in the presence of Candida albicans. There is a very significant correlation between the clinical symptoms, the cutaneous tests, and the lymphocyte activation tests. This abnormal reactivity essentially involves the CD8 cells.

[Allergy to mosquitoes and use of new immunobiological parameters]

With regard to an observation of anaphylaxis after a mosquito bite, we have shown by new immunobiological parameters and clinical investigations: Skin tests, specific IgE, Tests of Activation of basophils by flow cytometry (on basophils and total blood) and measurement of Leucotriene LTC4, the objective reality of the mechanism of IgE-dependent hypersensitivity (HS). This observation is correlated with rare work in support of true IgE-mediated allergy to mosquito 9 authors having used skin tests, PK in 1984 and immunoblot.

[Immunobiologic diagnosis of food allergy]

Food allergy is becoming more frequent, with 6% of asthmatics reporting an isolated food allergy, and 5 to 6% of atopic dermatitis patients also have either a single or multiple true food allergy. There is value in immuno-biological diagnosis by: Measurement of total serum IgE. Measurement of mono-allergen-specific IgE, following a measurement by a multi-allergen of the Trophatope type. A study of elimination of foods for 2 or 3 months followed by their re-introduction. Oral provocation tests in a hospital environment under clinical control and subsequent measurement of the mediators: Plasma histamine, tryptase, and urinary methylhistamine, to give proof of responsibility of the food allergen. Nowadays, it is perfectly possible to include in diagnosis the new technologies of the test of activation of basophils/or lymphocytes by means of flow cytometry.

[Histamine liberation in vitro or histamine release (HR). Study of the threshold of positivity in allergy to hymenopteran venoms]

The technique of histamine release in vitro (HR) is only usable in diagnosis of hymenoptera venom allergy. The allergen extracts that are supplied for clinical (skin tests) or biological diagnosis contain significant amounts of histamine, falsify the results, especially HR, and reduce significantly the correlation between HR and other biological or cutaneous tests. Dialysis of the allergen extracts significantly improves the sensitivity and specificity of the technique and lowers the threshold of positivity of HR from 30% to 12%. Correlation of HR with other diagnostic parameters:clinical history, specific IgE and skin tests is very significantly improved.

[Anaphylactic or anaphylactoid reactions to paracetamol. Report of 3 cases]

Anaphylaxis to paracetamol exists and perhaps nowadays diagnosis is not confined to clinical evidence of: The repeatability of clinical symptoms. Skin tests. Provocation tests. But also by immuno-biological evidence. Application of the test of Activation of basophils by Flow Cytometry and measurement of leukotriene C4 have been nowadays largely validated and constitute irrefutable proof of the responsibility of the drug as the origin of the clinical symptoms.

[Importance of in vivo and in vitro studies of leukotrienes. Application to the particular instance of aspirin]

The major role played by leukotrienes in the inflammatory reaction is today clearly demonstrated. These newly-formed mediators show powerful pro-inflammatory activities and their release from various cell types may be induced by agonists including the allergens. Therefore, leukotriene levels in biological fluids may represent a reliable image of the local or systemic inflammatory reaction and their release in vitro after incubation of the blood leukocytes in the presence of a specific allergen is today widely used for allergy diagnosis. Leukotrienes metabolism is deeply involved in aspirin intolerance or so-called pseudo allergy and, in spite of that the exact mechanism involved is still unknown, leukotriene release in vitro by ASA in the presence C5a represent the first reliable test for this diagnosis. The results of the recent clinical trials concerning the activity of anti-leukotrienes in vivo have led to a real therapeutic hope.

[Evaluation of the reproducibility of the MAST technique for pneumoallergens and food allergens. Biological study]

MAST-Cla reagent is used in France for now 10 years for the specific IgE determinations. Due to the different modifications of the manufactoring process we checked here the actual sensitivity of this test as compared to the results obtained by the CAP RAST RIA. The mean sensitivities related to the class 1 limit obtained by successive dilutions of the tested sera were respectively for the major aero-allergens and food allergens 0.40 kUI/l and 0.49 kUI/l. Four major allergens (grass pollen, house dust mite, egg yolk and milk) we observed a low background for 10 control subjects, the mean values (n = 6) related to a low concentration of grass pollen specific IgE (0.5 kUl/l) being significant (p < 0.01).

[Histamine liberation (or histamine release HR): study of the positivity threshold in hymenoptera venom allergy]

Dialysis of Hymenoptera venoms for measurement of HR by the radioimmunoassay technique (RIA, Immunotech) lowers the threshold of positivity of the HR titre from 30% to 12%. This modification of dialysis of the venoms significantly improves the sensitivity and specificity of the technique.

[Overview on RAST inhibition]

The technique of RAST inhibition is always useful in two cases: to study cross-reactions between the allergens; for more specific use of allergen indicated for desensitization. The comparison made in this article concerns dog allergens. As can be seen in the tables, diagrams and graphs, RAST inhibition by the dog allergen from the laboratories of DHS-Bayer-Pharma was clearer than that from the Laboratoire Stallergènes.

[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.

[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.

[A case of coconut oil allergy in an infant: responsibility of "maternalized" infant formulas]

The case is presented here of a baby of 8 months fed from her birth with maternal milks. The first milk induced a severe gastro-intestinal disorder which disappeared when a second milk was used. A third milk caused a relapse. The only common allergen was coconut, which was physico-chemically modified in the second milk. Demonstration of the responsibility of coconut oil was based on positive re-introduction tests, positive skin tests for coconut and maternal milk that were negative for cow's milk and peanut and by specific IgE tests which were positive in comparison with negative controls.

[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.

A non-linear compartmental model of human basophil activation

In this paper human basophil activation is modelled by means of a system of differential equations. The resolution of this system allows the justification of the incubation period and the unwedging period existing between the human basophil degranulation and the liberation of histamine.

A discrete mathematical model applied to human basophil activation

In this paper we present a model for the histamine negative feedback on the human basophil degranulation and another one for the feed-forward of these basophils on the extra-cellular histamine. These two models allow us to suggest a characterisation of the incubation time.

[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.

[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.