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Biomedical subjects

F Leynadier

Publications and source records attributed to F Leynadier.

At least 109 records · Page 6Linked to original sources

Blocking antibodies to inhalant allergens and asthma.

The mechanisms of specific immunotherapy are not still established. Among the lot of immunological changes, induced by immunotherapy, the increase of specific IgG 1, and then of IgG 4 antibodies, during the first months is well demonstrated. The skin-tests, the histamine-release and the human basophil degranulation are significantly decreased after incubation of allergen with the serum of desensitized patients. This antigen neutralizing capacity (blocking antibodies) disappeared when IgG 4 were suppressed from the serum by the mean of activated columns linked either with allergen, or protein A or antihuman IgG4 antibodies. Conversely, the total amount of serum blocking activity was found using pure IgG 4. However, the role of IgG 4 antibodies remains a subject of controversy. Since a clear correlation has yet to be established with symptom scores.

Allergens↗

Contact urticaria and anaphylaxis to natural latex.

Immediate allergic reaction to natural latex of Hevea brasiliensis has been well documented. We report 17 cases, all in women. Twelve had an anaphylactic reaction during surgery and five had contact urticaria. Reactions to prick tests done through a washed surgical glove and with natural latex were positive in 15 of 17 patients and in 16 of 16 patients, respectively; specific IgE was found in 12 of 17 patients. In 206 control subjects, results of a prick test through a surgical glove were negative.

Adult↗

[Predictive value of intradermal tests using muscle-relaxing drugs].

A retrospective postal inquiry was carried out to find out a possible relation between the results of intradermal tests carried out for a previous anaesthetic and the course of a second anaesthetic performed afterwards. This study included 350 patients who have had an intradermal test to vecuronium, alcuronium, suxamethonium, gallamine, pancuronium, thiopentone, fentanyl and droperidol between March 1984 and November 1986. Eighty-nine did not reply (25.4%), 183 (52.3%) did not undergo new general anaesthetic since the skin tests, whilst 78 (22.3%) did. The inquiry was then sent to the 73 anaesthetists corresponding to the last group of patients. The 51 complete answers included 62 anaesthetics. Twenty-four patients had negative intradermal tests before the new anaesthetic, the other 27 having had a test positive to at least one muscle relaxant. Of these latter, 16 were given a muscle relaxant during their general anaesthetic, selected among those resulting in a negative intradermal test. Thirteen had undergone skin testing because of an anaphylactic reaction during induction. No new anaphylactic reaction was observed. Three anaesthetists only were not aware of the results of the intradermal tests at the time of the new anaesthetic. These data tend to demonstrate that a muscle relaxant could be injected in a patient who has had a previous anaphylactic reaction with positive intradermal tests, provided that the drug chosen for the new anaesthetic does not give a positive intradermal reaction.

Adult↗

Anaphylaxis to latex during surgery.

Five young women, all of whom had anaphylactic responses in operating units, are described. Three of them worked in a hospital three showed immediate hypersensitivity to fruit and all had known urticaria to latex. Anaphylaxis appeared progressively 15 to 30 minutes after injection of anaesthetic drugs. Skin tests with these drugs were negative. Skin prick tests through gloves and with four different allergen preparations (saline which had been incubated with gloves and three kinds of latex) were positive. Human basophil degranulation tests with all four allergens were positive and radio allergo sorbent tests to latex were also positive. IgE-dependent allergy to latex may be investigated by questionnaire and if necessary by prick tests before each operation to prevent anaphylaxis due to surgical gloves.

Adult↗

Blocking activity of mite-specific IgG antibodies studied by skin tests.

The aim of the study was to determine whether IgG antibodies from patients on specific immunotherapy could inhibit skin test reactivity of allergens when mixed with them prior to testing. In a preliminary double-blind study, mite extracts were incubated with glycero-saline solution or non-specific IgG and used in testing 15 patients. Wheal and flare diameters produced with the two mite extracts did not differ significantly. In a second double-blind study with 15 other patients, skin tests using mite extracts incubated with either non-specific IgG or specific IgG showed significantly decreased diameters when mite extracts were preincubated with specific IgG. This result, in vivo, confirms the antigen neutralizing capacity of specific IgG demonstrated in vitro.

Adolescent↗

[Immediate hypersensitivity to latex: a new problem. Future perspectives].

From a series of 30 cases of immediate allergy to the latex of Hevea Brasiliensis, the authors recall the principal clinical aspects of these allergies, specially contact urticaria (during the use of surgical or cleaning gloves) and systemic anaphylactic accidents, essentially the anaphylactic shock during surgical procedures. They mention the diagnostic procedures; skin tests and measurement of specific IgE (RAST). They show the interest of biological research, yielding to the identification of the allergens of the latex in order to obtain non allergenic latex. Such a result would be of interest to limit the number of the accidents in a period where the use of rubber protective material is much larger/gloves and condoms).

Dermatitis, Contact↗

[Immediate allergy to latex. 12 cases].

Immediate hypersensitivity to latex is now well known. Contact urticaria is the most common manifestation, sometimes associated with rhinitis, asthma or a generalized rash. Atopy and frequent contact with latex favor sensitization. Anaphylactic shock is to be feared in sensitized patients during contact with latex, especially in peroperative situations (latex surgical gloves), as in the 12 cases reported. The shock is unusual in its delayed appearance and its progressive course. Positive skin tests to latex, the presence of specific IgE antibodies and negative skin tests to anesthetics confirm the diagnosis. However, the latex allergen has not yet been identified. Due to the increasing use of protective rubber (gloves, condoms, etc), the frequency of latex sensitization should increase. Systematic screening during history taking will be important before treatment.

Adolescent↗

[Mast cells and basophils in asthma].

Airway inflammation may contribute to the nonspecific bronchial hyperreactivity, which is a prominent feature in chronic asthma. Many stimuli such as allergens in allergic asthma, virus and irritants may induce an early reaction and in some cases a late reaction. An increase of nonspecific bronchial hyperreactivity is well demonstrated after this late reaction but no after the early one. Although a variety of inflammatory cells may be located within the respiratory tract, the late phase is generally considered as a direct consequence of the effects of mediators released from mast cells activated during the early reaction. Eosinophils and other inflammatory cells are attracted by chemotactic mediators such as PGD2. However the pathophysiology of chronic asthma remains uncertain because the heterogeneity of mast cells and the complexity of intercellular regulations. The role of basophils has been suggested mainly because their number increases during the late phase of allergic process. On the other hand, histamine and LTC4, but not PGD2, are found during the late phase: it is well established that basophils do not release PGD2. Two recent hypothesis have focused interest on basophils: the higher releasability property of basophils obtained from allergic and asthmatic patients, whatever their serum IgE and the presence of histamine releasing factors acting only on one kind of IgE (IgE+) which is apparently found in severe asthmatic patients. It may be probable that other cells, such as epithelial cells, play also a prominent role in chronic asthma.

Allergens↗

Serum sickness with acquired precipitating antibodies during rush immunotherapy (2 cases).

Serum sickness can be induced by several heterologous proteins. Two patients undergoing rush immunotherapy developed clinical symptoms of serum sickness. One patient received a mite and grass pollens mixture and the second patient a wasp and yellow-jacket venoms mixture. Precipitating antibodies against some allergens used for immunotherapy were found in their serum during the disease but not in the sera drawn before immunotherapy and two and three months after. Pathologic findings showed a leukocytoclastic vasculitis. Pathogenesis of this complication is discussed.

Antibodies↗

[Skin tests and chymopapain-specific immunoglobulins E after chemonucleolysis].

Skin tests (prick tests) with chymopapain were performed on 3 groups of patients: 75 patients awaiting chemonucleolysis with chymopapain (group I), 42 of these 75 patients 2-3 weeks after chemonucleolysis (group II), and 60 atopic patients suffering from asthma and/or rhinitis with positive skin tests to at least one of the airborne allergens (group III). A positive skin test was found in one patient of group I (1.33%), one patient of group III (1.7%) and 11 patients of group II (26.2%). Thus, sensitization to chymopapain is not more frequent among atopic patients, and chemonucleolysis has a highly significant (P less than 0.001) sensitizing effect. Chymopapain-specific IgE's were found in one out of 75 patients (1.33%) before, and in 14 out of 45 patients (31%) after chemonucleolysis; the difference was significant (P less than 0.001). Concordance between skin tests and specific IgE's reached the 74% level. Our results are consistent with those of the literature. They show that prick tests with a 10 mg/ml solution of chymopapain constitute, for the time being, a simple, reliable and cheap method for detecting subjects at risk.

Adult↗