Artériopathie et hétérogénéité artérielle

More and more clinical observations and trials support the concept of heterogeneity of atheroma according to the arterial bed. In a pilot study named “Étude Comparative des Lésions Athéromateuses” (ECLA), we have shown that carotid and femoral plaques possess different characteristics. Carotid arteries display increased lipid content compared to femoral arteries whereas femoral arteries are more prone to calcify and to develop osteoid metaplasia. These observations should lead the researcher and the clinician to look at the cellular and molecular mechanisms governing the heterogeneity of atheromas. At last, a better understanding of the characteristics of plaques should help us to determine plaque stability, to prevent cardiovascular events and to choose the best medical, endovascular or surgical option.     

L'asthme est-il déjà « en marche » avant l'atopie ?

Asthma is often considered a step in the natural history of atopy, occurring between atopic dermatitis and allergic rhinitis. However, several lines of reasoning suggest that the development of asthma is an independent phenomenon. The importance of events occurring during the prenatal period is probably underestimated. Atopy probably occurs afterward, the onset of allergic sensitizations consequently exacerbating the asthma. Nevertheless, once developed, the two entities interact in a complex manner, since they probably share common immunologic regulatory mechanisms.     

Allergie aux protéines du lait et aux hydrolysats de protéines de lait : à propos d'une observation au diagnostic retardé

The authors report the case of an infant with a history of eczema due to cow milk and who later had two bouts of urticaria after drinking milk protein hydrolysate. The particular interest in this case is the disconnection between the onset of the eczema (when an allergy workup was not predictive) and the subsequent finding, one year later, of positive IgE-dependant sensitization tests.     

Allergies croisées : de la théorie à la pratique

The notion of allergic cross-reactions must from now on be regarded by allergists as an indispensable element of the diagnostic and therapeutic approach. Indeed, knowledge of proteins and of mechanisms involved in this type of phenomenon is of interest to physicians not only in with regard to pathophysiology but also as an aid in interpretation of certain clinical history data and the results of skin or biological tests. Moreover, it makes the management of patients more rational, and probably in therapy of the future when recombinant allergens will be more widely used.     

Sensibilisation parentérale du lapin aux protéines du lait de vache : effets sur la perméabilité intestinale

Objectives

Study of the cow's milk protein intolerance mechanisms in order to knowledge, in which could proportions spread the permeability of intestinal to the β-lactoglobulin and α-lactalbumin at the rabbits sensitized to these two proteins.

Methods

The rabbits were sensitized to these proteins by subcutaneous way and their degree of immunization established by Elisa dosage of the specific IgG. For the study of the transepithelial exchanges, the interaction of the proteins (marked to the ¹⁴C-formol), with the mucous intestinal of sensitized and some control rabbits were follow-up in vitro on fragments of ileums mounted in Ussing chamber. Their transepithelial fluxes were measured, after stimulation by the proteins deposed in the mucous compartment from a sampling made from serosa side.

Results

The animals sensitized present some titers in IgG anti β-lactoglobulin and anti α-lactalbumin, as well as some transepithelial fluxes, significantly more increased than control animals.

Conclusion

These results suggests that at the immunized animals, the interaction of the sensitizing protein with intestinal mucous caused some anomalies of hydroelectrolytic transport.     

Mise au point d'un dosage automatisé des IgE spécifiques des allergènes des pollens de cyprès et de genévrier par VIDAS Stallergy

Study objective

Cypress pollen is a significant cause of allergies in the Mediterranean area. In order to improve the in vitro diagnosis to cypress sensitization, we used a Juniperus ashei extract to develop a new semi-quantitative test for the measurement of IgE specific to juniper and cypress pollen allergens based on the VIDAS automated system.

Methods

The VIDAS Stallergy^® assay combines a two-step enzyme immunoassay sandwich method with a final fluorescence detection. The reagent comprises the Solid Phase Receptacle (SPR) coated with a J. ashei extract, which serves as a solid phase as well as a pipetting device during the assay and a strip that contains all the ready-to-use reagents.

Results

The precision study shows coefficients of variation lower than 1.7% for intra-assay variability and between 1.6 and 9.5 for inter assays variability. Correlation with the CAP system^® method shows an 80.7% agreement to the nearest class (N = 57). For 65% of sera class results are similar with the two techniques, and for 33% of sera, class results are higher with the VIDAS method. Test specificity is confirmed by VIDAS inhibition experiments. A sensitivity study performed using 82 clinically recognized cypress allergic patients shows that 97.6% of the patients are detected with the VIDAS Stallergy^® Juniper reagent.

Conclusion

The Juniper Stallergy^® test allows to measure specific IgEs to cypress pollen, with a sensitivity of detection at least similar to the CAP system^® method.     

L'allergie au tournesol et à son huile : rôles du contact,de l'ingestion et de l'inhalation

We report the case of a 5-years old girl with food allergy to sunflower oil. Sensitivity to sunflower oil and seeds was demonstrated by skin tests whereas assays of serum for sunflower-specific IgE were negative. An oral challenge test with 54 ml of sunflower oil was positive. The patient also reacted to cutaneous contact and inhalation of sunflower seeds. Depending on the route of contact –– skin contact, ingestion or inhalation –– sunflower oil and seeds can trigger symptoms such as urticaria, erythema, vomiting, dyspnea or fatigue.     

Pustulose exanthématique aiguë généralisée liée à l’hydroxychloroquine : à propos d’une observation

We report a 45-year-old woman who presented an acute generalized exanthematic pustulosis induced by hydroxychloroquine. Acute generalized exanthematic pustulosis is a severe eruption that is usually drug related. This side effect should be known as new therapeutic challenge would induce more severe clinical features.     

Tolérance ou réactivité aux allergènes

The default response to allergens is peripheral tolerance, often partial, mainly through immune deviation or suppression by adaptive regulatory T cells. Functional plasticity of dendritic cells and T cells on contact with antigens plus the modulating effects of infection may lead to a failure to acquire or a rupture of immunological tolerance to allergens in genetically predisposed individuals. Specific immunotherapy can restore tolerance by switching allergen-specific responses to less polarized lymphocytes and/or by activating regulatory T cells and IL-10 production.     

Étude de la faune acarologique des matelas de l'île de la Martinique

Background. – Levels and types of species of house dust mites (HDM) can vary according to environmental conditions. The objective of this study is to describe various species of house dust mites (HDM), which colonize mattresses in Martinique, a tropical island of the Caribbean, and to find out differences according to the characteristics of the mattress and housing.     

Hyménoptères d'Europe et du bassin méditerranéen. Aperçu de la classification des espèces à aiguillon ; facteurs de risque

Among the hymenoptera, only the aculeate taxa are able to inflict bites by means of their venomous stingers. The diversity of this group in Europe will be reviewed briefly, focussing on families classically known for their ability to induce allergic reactions (the social insects: apideae, vespidea, formicidea), and a few comments will also be made about members of the several thousand less frequently encountered non-social families that humans come in contact with accidently. It is indeed highly likely that certain atypical reactions or those apparently unrelated to known venoms are caused by solitary hymenoptera encountered by chance during various experiences in the countryside as well as in abundantly inhabited areas.     

Thrombopénie immunoallergique à la rifampicine : à propos d'un cas

Rifampicin can induce toxic and hypersensitivity reactions. However, immediate hypersensitivity (IgE-mediated) reactions are rare. In contrast, other types of reactions, among which are the immunoallergic thrombocytopenias, are not exceptional. We report the case of a 73 year-old man with pleural tuberculosis who reported having hemorrhagic and purpuric symptoms five hours after beginning treatment with rifampicin, isoniazid and pyrazinamide. A diagnosis of rifampicin-induced immunoallergic thrombocytopenia was made, based on extrinsic and intrinsic etiological criteria, despite a negative specific serum antibody assay and a borderline positive rifampicin skin prick test. No previous treatment with rifampicin was reported by the patient, except for prior prolonged self-administration of eye drops that may have contained rifampicin. This adverse effect cannot be explained by an immediate type hypersensitivity reaction, but probably resulted from a type II or III hypersensitivity reaction, as suggested in the literature. The short interval between the beginning of treatment and the onset of symptoms may have been a consequence of earlier sensitization to rifampicin-containing ophthalmic drops. In conclusion, we report a case of rifampicin-induced immunoallergic thrombocytopenia. This case illustrates the limits of diagnostic tests for drug allergy, especially for type II and III hypersensitivity reactions. It also raises the question of the sensitizing potential of drugs administered locally, as well as the question of the necessity of informing physicians and patients of this possibility.     

Choc anaphylactique à l'Augmentin chez une patiente présentant des tests cutanés et un test de provocation négatifs à l'amoxicilline

Mme M. was seen in consultation with a history of possible allergy to penicillin. The patient reported that three months earlier she had experienced the sudden onset of a generalized but not very severe urticarial reaction, which included swelling of the face, beginning four days after taking amoxicillin, but not any other medication. She was not aware of any previous reaction associated with taking any drug, including penicillin. Skin tests with major and minor penicillin determinants, and then with amoxicillin, up to a concentration of 20 mg/ml intradermally were negative. It was then elected to do an oral provocation test with amoxicillin. She tolerated a single 1 g oral dose perfectly well. Eighteen months later, she was seen again following an episode of anaphylactic shock that had begun immediately after taking 1 g of amoxicillin associated with clavulanic acid (Augmentin^®). Between the two consultations, the patient had received no betalactamines, whereas she had tolerated two courses of treatment with macrolides. At the second consultation, skin tests with penicilloyl-polylysine and amoxicillin were definitely positive. This observation suggests two hypotheses, which are not however mutually exclusive: 1) The low predictive value of skin and provocation tests in patients weakly sensitized (Could such patients continue treatment with amoxicillin for several more days?); 2) the possibility that an initially weak sensitization was potentiated by the skin and provocation tests (Is it advisable to systematically do a second allergy workup several weeks after the first one to exclude the possibility of sensitization in this type of patient?).     

Résultats de tests cutanés intradermiques sur un groupe de sujets contrôles avec le rocuronium et le cis-atracurium à la concentration de 1/10

To investigate the cause of a pre-operative adverse reaction, intradermal tests are the validated method used for the diagnosis of immediate allergic reactions to curares. The maximal concentrations to be injected are still under discussion. The aim of this study was, therefore, to show that tests done with 1/10 dilutions of rocuronium and cis-atracurium lead to false positive reactions. Twenty-six healthy volunteers were tested with rocuronium and 53 with cis-atracurium. Intradermal tests were done with concentrations of 1/10 (1 mg/ml and 0.1 mg/ml, respectively), the cutaneous responses being read 15-20 minutes later. A wheal with a diameter of at least twice the diameter of the wheal produced by the injection was considered positive. Our results showed a tendency toward nonspecific histamine liberation at the concentrations of the two myorelaxants used. Thus, we observed positive reactions in 11/26 (42%) of the rocuronium controls and 19/53 (36%) of the cis-atracurium controls. Our results support the present recommendations of the Société Française d’Anesthésie et de Réanimation concerning the dilutions to be used with rocuronium and cis-atracurium to avoid false positive skin tests. In screening for peri-operative allergy, the maximum concentration used in intradermal testing with these two curares should not exceed 1/100.