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J Sainte-Laudy

Publications and source records attributed to J Sainte-Laudy.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Biological assays in allergology: constraints, concepts, criteria, and methods of evaluation].

The in vitro diagnosis of allergies is submitted to several constraints some shared by all the in vitro methods and some which are specific of immuno-allergology. The in vitro diagnosis of allergies involves various parameters among which the allergen by itself is far the most complex. On the basis of a studied population having an optimal size, the most powerful statistical parameters are the positive predictive value, the negative predictive value and the efficiency. The bio-clinical correlations lead to the involvement of another parameter which is the prevalence of the clinical reaction which may be corrected by a clear clinical history. Finally, the absence of absolute gold standard in allergology lead to the conclusion that allergy diagnosis is still based on the synthesis of various clinical and biological arguments.

Allergens↗
PubMed1999

[Evaluation of allergic-type reactions to antibiotics and rapid immunotherapy].

Adverse effects of medications, most notably antimicrobials, are becoming increasingly common and raise difficult challenges in the area of clinical pattern definition (wide variety of symptoms, polypharmacy in many cases), diagnosis, and methodology (need for a rapid diagnosis, frequent obscurity of causative mechanisms, and less than ideal reliability of laboratory techniques). Sixty patients were treated by rush immunotherapy to one or more antimicrobials. The pretreatment evaluation included oriented history taking, skin tests, blood cell counts, IgE assays, and cell activation tests (basophils and lymphocytes). The results of this study confirm the usefulness of skin tests (intradermal, prick, or patch tests), which provided etiological orientation in 54 of the 60 cases. They also provide additional evidence of the lack of reliability of currently available in vitro tests (only 29 of the 60 tests were positive).

Anti-Bacterial Agents↗
PubMed1999

Anaphylactoid and anaphylactic reactions to iodinated contrast material.

Some adverse reactions to iodinated contrast material (ICM) are considered allergy-like, with cutaneous, cardiovascular, respiratory, and digestive symptoms. Allergy-like reactions are usually unpredictable. Reactions are more frequent with ionic than with nonionic material, but the frequency of deaths is almost identical. In a recent study, 20 severe unexpected reactions to ICM, including 10 life-threatening reactions and one death, were investigated by measuring mediators in blood, within the first minutes or hours of reaction. The responsible ICMs were mostly ionic materials. Histamine and tryptase release correlated with the severity of the reaction. Specific IgE against the responsible ICM was significantly higher in reactors than in controls. A few patients had positive skin tests to the administered ICM, suggesting type-I allergic reaction. Only 2.4% and 3.1% of the cases yielded a positive IgE-RIA, in a second retrospective study which included 165 patients recruited during a 4-year period. In conclusion, IgE-mediated anaphylaxis is rare, but it may be one of the possible mechanisms of severe adverse reactions to ICM.

Anaphylaxis↗
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↗
PubMed1998

Recognition of an extensive range of IgE-reactive proteins in cod extract.

Allergy to fish is one of the most common food allergies. Gad c 1 is the only fish allergen which has been purified and characterized. Other allergens have been detected by Western blot in cod extracts. We have now improved the Western-blot procedure in order to characterize fish IgE-reactive proteins from extracts prepared under different conditions: pre-rigor mortis and post-rigor mortis, EDTA addition or not, and DEAE ion-exchange chromatography. Several IgE-reactive protein bands have been identified over a wide molecular-weight range. In particular, the 104- and 130-kDa IgE-reactive protein bands were detected. These new bands may correspond to aggregates, as EDTA increased the relative amount of the 60-, 67-, 104-, and 130-kDa IgE-reactive protein bands in Western blot. All these bands were also detected by antiparvalbumin monoclonal antibody, specific to the first calcium-binding site. The longer period of storage increased the relative amounts of the 41-, 80-, 104-, and 130-kDa IgE-reactive protein bands. The 18-kDa band was detected only in fish stored for several days. In conclusion, we have described IgE-reactive protein bands over a wide molecular-weight range (12-130 kDa) in Western blot of cod extract, and shown that EDTA and storage conditions may influence the relative distribution of IgE-reactive protein bands.

Adolescent↗
PubMed1998

[Application of flow cytometry to the analysis of activation of human basophils. Immunologic validation of the method].

Among the different methods used for the analysis of human basophil activation as histamine and leukotriene release, flow cytometry presents several methodological advantages. Moreover, preliminary results obtained for a wide allergen panel have demonstrated its high sensitivity and specificity. We present here the results of the methods used to validate the flow cytometric analysis of human basophil activation by double anti-IgE FITC/anti-CD63 PE labelling of human leucocytes. The use of multiple labelling by monoclonals having different specificities have shown that the selected cells express the phenotype CD14-, CD19-, CD41- or +/-, CD45+, CD63- or +. This phenotype is related to human basophils. We have also demonstrated that the expression of CD63 is related to basophil activation and not to aggregated platelets which are also able to express this marker.

Antigens, CD↗
PubMed1998

[Testing basophil activation by flow cytometry in the diagnosis of allergy to hymenopteran venom].

Diagnosis of allergy to hymenoptera venom must be precise and depends on indisputable bio-clinical criteria, because of specific immunotherapy for indications such as systemic and/or anaphylactic reactions. Until nowadays, diagnosis was by specific IgE, histamine release and skin tests, most often done for the venoms of wasp, honey bee and hornet at the same time since, in 7-8 cases in 10 the patients had not identified the responsible insect. Basophil activation test (TAB) by Flux cytometry and measurement of leukotriene C4 (LTC4) are new techniques of great reliability. The work shows the correlations between the different immunobiological parameters by reference to TAB by CAF and measurement of LTC4. When the overall results for mixed venoms or those for single venoms are considered, the correlations between TAB, LTC4 and the other parameters are highly significant. It can now be considered objectively that TAB by CTF and measurement of LCT4 are the two highest-performing techniques for diagnosis of hymenoptera venom allergy and so validates them.

Basophils↗
PubMed1998

[Allergic immunobiology and anesthesiology].

A protocol has been produced for the study of anaphylactic accidents that occur post-operatively that allows definition of the anaphylactic origin, and so reactions that are mediated by IgE in post-operative accidents. This protocol occurs in two stages, the first is done in the minutes and hours that follow the anaphylactic accident, and the second a month or 6 weeks afterwards. At first, we evaluate the sequential study of the liberation of the mediators of anaphylaxis, plasma histamine, serum tryptase, urinary methylhistamine and, more recently, leucotriene E4. The second study is devoted to reactions that are mediated by IgE, essentially, specific serum IgE, tests of activation of basophils by flow cytometry, measurement of leucotriene C4 and skin tests. A study on 16 subjects has evaluated and validated the protocol and shown a significant level of correspondence of results between the sequential measurement of mediators on one hand and on the other the search for IgE-mediated reactions every time that there was an anaphylactic reaction.

Adolescent↗
PubMed1998

[Comparison of the levels of histamine, tryptase, and interleukin-6 for the investigation of anaphylactoid drug reactions].

The biological exploration of the anaphylactoid reaction is based on tryptase and plasma histamine determinations. As this reaction may be considered as a particular case of the acute inflammatory reaction, we have compared, on 25 subjects having presented a drug induces anaphylactoid reaction grade 1 to 3 the plasma level of tryptase, histamine and interleukin 6 (IL6) at 30 and 90 min. On a population of patients having presented an increase of plasma histamine and/or tryptase (n = 14), we have shown that the concentrations of tryptase, histamine and IL6 respectively plateaued (63.9 +/- 70 micrograms/l et 74 +/- 102 micrograms/l), decreased (82.5 +/- 102 mmole/l et 20.5 +/- 27 mmole/l), or greatly increased (19.5 +/- 25.3 ng/l et 320 +/- 745 ng/l) at 30 and 90 min. Correlation between IL6 and the two parameters was only significant for tryptase at 30 and 90 min. Due to the longer lasting kinetic of IL6 (48 h) as compared to histamine and tryptase, IL6 could have a place in the immediate exploration of the anaphylactoid reactions, these results having to be completed by studies on a longer delay and on groups of well defined clinical reactions.

Anaphylaxis↗
PubMed1997

[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.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

[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.

Animals↗
PubMed1997

[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.

Animals↗
PubMed1997

[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.

Acetaminophen↗