Biomedical subjects
F De Blay
Publications and source records attributed to F De Blay.
Comparison of genetically engineered hypoallergenic rBet v 1 derivatives with rBet v 1 wild-type by skin prick and intradermal testing: results obtained in a French population.
BACKGROUND: Bet v 1, the major allergen in birch pollen, is recognized by more than 90% of patients allergic to birch in northern and central Europe. Immunotherapy is commonly performed with birch pollen extracts. Recently, hypoallergenic derivatives of Bet v 1 (rBet v 1 fragments, rBet v 1 dimer and trimer) were constructed and purified. OBJECTIVE: Our aim was to compare the allergenic activity of wild-type rBet v 1 with recombinant Bet v 1 derivatives (rBet v 1 fragments, dimer and trimer) with potentially reduced anaphylactic activity by skin testing in a French population. METHODS: Among the 36 birch pollen allergic patients included in the study, 29 were tested by skin prick testing and 30 by intradermal injections with purified monosubstances: rBet v 1 fragments (F1: aa1-74 and F2: aa75-160), Bet v 1 dimer and trimer. Intradermal tests were performed by the end-point intradermal titration method. Eight of the intradermally-tested patients were previously hyposensitized. Tests were performed over a period of 6 months (before, during and after birch pollen season); Bet v 1-specific IgE and IgG4 subclass responses were measured by immunoblotting and ELISA. RESULTS: All patients showed lower reactivity with the modified rBet v 1 allergens, both in skin prick and intradermal tests. In 25 and 23 out of 29 patients the lowest concentration of fragment 1 and 2, respectively, resulting in a positive prick test was 100-fold higher than the lowest concentration of monomer resulting in a positive prick test. For dimer it was 100-fold or more in 25 out of 29 patients, and for trimer it was 100-fold or superior in 26 out of 29 patients. By intradermal testing, the end-point concentration was 160-fold higher for trimer than for monomer in 24 patients and 40-fold higher in five patients. For the two fragments the end-point concentration was 160-fold higher in 20 out of 22 patients. CONCLUSION: Genetically modified hypoallergenic derivatives of the major birch pollen allergen, Bet v 1 showed reduced capacity to induce immediate type skin reactions. They may represent candidate molecules for immunotherapy of birch pollen allergy with reduced risk of anaphylactic side-effects.
[Respiratory allergies and household allergenic environment].
Based on immunoassay techniques used to identify and quantify major indoor allergens, epidemiological studies have demonstrated that level of exposure depends on the geographical situation (climate, urbanization) and that there is a relationship between exposure and sensitization of predisposed patients. Most of the major mite allergens are proteases. For mammals and cockroaches, the major allergens belong to the retinal protein binding group. Determination of the airborne characteristics of the major indoor allergens is helpful in better understanding the pathophysiology of asthma. In the future, more precise diagnosis and more efficient immunotherapy will be possible through the development of recombinant allergens. The efficacy of allergen avoidance in allergic asthma has been demonstrated in several studies. Thus the respective role of different household allergens should lead to improved diagnosis and treatment of allergic diseases.
[Pollution and asthma].
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[New aero-allergens].
As the number of proteins recognized as causing allergic respiratory diseases increases, new aero allergens have appeared in the animal and vegetable realms, both in home and professional environments. Lepidoglyphus destructor and Blomia tropicalis, two mites found in storage areas, are particularly important in agricultural areas and in homes. Over the last ten years, the frequency of reactions to cockroaches has also increased in several countries. The allergenicity of non-biting insects is a frequent cause of allergy in certain countries including Japan. Chironomides cause respiratory diseases in professional and outdoor environments. The important role of Alternaria, a mold, in producing severe asthma has also been demonstrated. The pathophysiology of pollen-induced asthma has been shown to result from pollen allergens carried by particles less than 5 microns in diameter. Cyprus and ash tree pollen also cause an increasing number of pollinoses and flowers can cause rhinitis and asthma. Respiratory allergy to Ficus benjamina inaugurated a new type of allergies caused airborne allergens from non-pollinating plants. Allergy to latex raises a particular problem for health care workers. The immunochemical structures of the major and minor airborne allergens are now better known and the homologous structures of different allergens largely explains certain cross-reactions. In the future, recombinant allergens will probably be used to better understand the role of allergens in inducing and maintaining the allergic reaction and should help in our approach to diagnosis and therapy.
[A cause of respiratory distress: eosinophilic pneumopathy due to minocycline].
We report a case of eosinophilic pneumonia secondary to taking Tetracycline whose severity required the use of mechanical ventilation and steroid therapy. On the basis of this case, we review the characteristics of drug-induced pneumonia as well as the differential diagnosis which are evoked.
[Metrology of airborne particles carrying the principal air allergens].
The relationship between exposure to aeroallergens and the acquisition of allergy and asthma has been shown over the past ten years. Thanks to new developments for detecting major allergens amongst the principle aeroallergens, in future it will be possible to measure their airborne concentration and to determine the particle size of particles carrying them. We report the results obtained from three studies in which we have shown that airborne mites Group I and II and cockroaches Bla g 1 and Bla g 2 allergens have a broadly similar airborne behaviour. That is to say that they are not measurable unless the atmosphere is artificially disturbed and they are carried principally on particles of > 10 microns. On the other hand, 30-40% of cat allergens are carried on particles < 5 microns and measurable in the air without any artificial disturbance. According to our data and those of the literature, we propose a different classification for aeroallergens according to characteristic aerodynamics. Although some progress in the standardisation of techniques for sampling airborne allergens may have been accomplished, other studies are required to improve their reliability in order that airborne measurements can become a marker of allergic exposure in both domestic and occupational environment.
[Demonstration of major cockroach allergens in house dust by the ELISA test].
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[Evaluation of the prognosis in sarcoidosis: remission as an issue of biological criteria and current cellular activities (ACE and alveolar lymphocytosis)].
The spontaneous evolution of 60 patients suffering from recently diagnosed sarcoidosis was compared with their initial biological profile of "activity". 47% of this unselected group of patients belonged to an inactive group (ACE less than 35 nmol/ml/mn and the percentage of alveolar lymphocytes less than 30%). After a mean period of two years of follow up it turned out that the initial bioprofile of activity had no predicted value, even in the absence of any initial elevation of the markers (3 cases out of 28 grew worse). The repeated controls of criteria of activity did not objectively show any concordant change with the outcome in such cases. It is necessary to point out the unfavourable character of very raised ACE activity greater than 50 nmol/ml/mn (7 deteriorations out of 8 cases). It would appear that a systematic search for these criteria should be deferred principally in type 1 lymph node involvement or pulmonary and mediastinal type IIA, all the more so as in practice they have little influence on therapeutic decisions.
[Survey of the attitude of specialists faced with bronchial small cell carcinoma].
The practice of therapeutic trials is indispensable in the management of bronchial carcinoma if one hopes to improve the results. We have questioned 134 doctors in the Alsace region who are involved in the diagnosis and treatment of bronchial cancer. We asked how they would wish to be treated if they had a small cell cancer, and if they would agree to participate in a therapeutic trial should the occasion arise. Four different clinical situations of small cell carcinoma localised to the hemithorax were presented, illustrating current controversy on the best treatment or treatments to apply. The 4 proposed protocols were refused by 50% to 84% of the doctors questioned in different cases. The greater the level of consensus on a therapeutic treatment in a given clinical situation the greater the level of refusal to participate in a randomised protocol was. The fact that at least half of the specialist doctors questioned would refuse to be included in a current therapeutic protocol which is underway for patients in Europe leads to the suggestion that before the application for new protocols experts surrogates should give their opinion in association with ethical committee.
[The advantage of and strategy for eliminating household allergens in pediatric asthma].
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