Revue francaise d'allergologie et d'immunologie clinique最新文献

Case report

In a 16-year-old teenager hospitalized with a severe asthma attack, the diagnosis of severe asthma associated to allergy and current tobacco smoke and allergen exposure is confirmed. Despite the use of high dose of inhaled antiasthma medication, the disease remains uncontrolled and anti-IgE, omalizumab treatment is started. After few weeks, respiratory symptoms and function dramatically improve.

Conclusion

Severe asthma must be readily diagnosed in order to adapt treatment and avoid fatal outcome or respiratory disability.

Symptoms of subjects presenting with rhinitis, conjunctivitis or contact urticaria when exposed or in contact with grass are usually attributed to allergy to grass pollen or to certain airborne molds. The four cases described in the present report presented with allergic symptoms when mowing their lawn. The suspicion of allergy to grass leaves was confirmed by skin prick tests with native leaves. An extract of rye grass leaves was made and its allergens were analyzed by SDS-PAGE and immunoblotting. Three of the four patients were found to have IgE specific for a single 56 kDa molecule. It was shown to be a major leaf protein and identified as a subunit of ribulose 1,5 diphosphate carboxylase/oxydase, a major plant kingdom enzyme involved in photosynthesis. This protein is widely present in leaves and is, in addition, used as a non-allergenic model in investigation of the allergenicity of food proteins. In fact, it is degraded instantaneously by digestive enzymes, in contrast to the known principal food allergens. In conclusion, respiratory allergy to grass leaf proteins was demonstrated in this study of four patients, who were or were not allergic or sensitized to grass pollen.

Aim of the study

We tested here a new cytometric method based on the use of two activation markers (CD63 and IgE) and result's expression in activation index (AI).

Material and methods

Twenty-six allergic patients and 23 controls having received a neuromuscular blocker (NMB) have been selected on the basis of clinical history, skin tests and specific IgEs. NMB were tested mixed (n = 26) or alone (injectable form, (n = 30) and allergens commercialized for flow cytometry (n = 9)). Concentrations used were the same than for IDR according to the recommandations of the French Society of Anaesthesia and Resuscitation (SFAR). The cytometric protocol used was the IgE/CD63 protocol, results being expressed in percentage CD63 and in AI calculated by a specific algorithm involving the mean fluorescence intensity (MFI) of the IgE+ and the CD63+ and − populations.

Results

In the technical described here NMB exhibited no toxicity even for concentretions 10 times higher than concentrations used for diagnosis. With the injectable form, the respective sensitivities observed for CD63 alone and the AI were 68 and 100% for the mixture of NMB and, 67 and 100% for the isolated NMB. With the NMB commercialized for flow cytometry, sensitivities were 47 and 100%. Specificities were 100% for CD63 alone and 98% for the AI. The link (Chi²) between skin tests and flow cytometry was significant for the two markers and the two allergen types. Correlation between AI and specific IgEs was not significant.

Conclusion

The new flow cytometric protocol described here has the necessary characteristics of a biological test which could be included in the pre-anaesthetic check up.

Asthma is children's foremost chronic disease. If the medicinal progress is unambiguous, therapeutic education as well as rehabilitation efforts are integral parts of asthmatic children's global care. Initiated and proposed by the Association asthme et allergies, a protocol that defines place, dates, purposes and means, received the agreement of the French ministry for Youth and Sports. Thirteen children (eight boys, five girls, with an average age of eleven) who suffer from persistent asthma, from moderate to severe and/or exercise-induced asthma, were selected by two Parisian hospitals. The children spent fourteen days on vacation in Ardèche (altitude, 1400 m) during the month of July and were supervised by a medical and an animation team. Motivating children to engage in sports activities and strengthening therapeutic education trained in asthma's schools (écoles de l’asthme) were the dual purpose of the stay. An educational diagnosis and an evaluation of the knowledge of each child were realized at the beginning and at the end of the stay. A flexible program was set up and combined outdoor games, role-playing, educational workshops on breathing, techniques of inhalation and measurement of breath… associated with tests and coupled with physical or sportive activities practiced individually or collectively. Climatic conditions did not provoke any asthma attack or intercurrent affection. The questionnaire dispensed at the end of the stay reveals the children's global satisfaction. In terms of health, preliminary results are promising, particularly regarding their aerobic capacity and physical performances. A medium-term evaluation is in progress, but consequences of this experience – shared by children coming from different social milieus and in a less polluted environment – seem to confirm the interest for promoting educational and sportive stays supervised by health professionals specialized in therapeutic education and spent in specific places which correspond to the standards of allergens’ eviction.

Corticosteroids are widely used for their anti-inflammatory and immunosuppressive properties in the treatment of respiratory, allergic and autoimmune diseases. Their adverse effects are well known, but allergic reactions to these drugs are relatively rare although they are sometimes severe. While the route of administration was different in the two cases reported here – one oral, the other by inhalation – the adverse reactions began soon after administration and presented the same symptoms, namely, cough, dyspnea and wheezing. Skin tests and/or provocation tests are essential to confirm the diagnosis. They require tests with different groups of molecules. For our young asthmatic patient, the results were positive for only one group of corticosteroids, which allowed us to prescribe an alternative treatment.

Phototesting data as MED value or Repeated Phototest are necessary for the diagnosis of a Photosensitivity disease. To identify the photoallergen of Photoallergic reactions, photo-patchtests are efficient and eviction may be done. Practical aspects of the realisation of the tests are developed. Possibilities of phototesting by Allergologic Center in which specific irradiation devices are not available are proposed. The relation ship with a positive test and the present eruption is discussed.

Many eating disorders are observed in food allergy practice. It is common to see patients avoiding many foods because they have been poorly informed of cross-reactions that are not clinically relevant. For children, parental anxiety may multiply irrational avoidance. The diagnosis of Münchausen syndrome by proxy should be envisaged, although it is rare. Abnormal eating behavior in children can be related to a Pavlovian reaction of disgust, to anxiety or depression, a perturbed relationship with the mother or simply due to an aversion to new foods. In adults, food avoidance is linked to poor interpretation of positive laboratory tests indicating cross-reactions that are clinically irrelevant. Irritable bowel syndrome results in food avoidance even where food allergy is poorly documented. Fibromyalgia also leads to unnecessary avoidance diets. True neurosis (obsession and anxiety neurosis) may occur. Patients taking alternative medicines or belonging to certain sects often follow aberrant avoidance diets. All patients should undergo a nutritional evaluation. Psychologists, psychiatrists and dieticians should also be involved in treatment. Allergists should not limit themselves to simply eliminating food allergy to a given food allergy, but should make patients aware that problems arise from “not” eating different foods. Accurate tests, detailed information and careful monitoring of proposed changes in diet should result in more rational eating habits. Established neurosis will not improve, since patients are in denial about these disorders, psychiatrists know little about them.