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Resume A l'aide de resultats experimentaux obtenus en allergologie, on definit quelle strategie experimentale doit etre utilisee, lors-qu'on etudie le lien pouvant exister entre une symptomatologie et un parametre biologique mesurable (test biologique), ou lorsqu'on desire evaluer si ce test biologique peut etre pratique dans un but diagnostique. Dans le premier cas, les etudes de comparaisons de moyennes correspondant a des groupes d'individus differents vont permettre de repondre a des questions sur la relation entre un type de pathologie et la valeur experimentale des parametres mesures, analyses qui peuvent etre ensuite approfondies par des etudes de correlation. Dans le second cas, sont definis les criteres retenus comme indispensables pour valider un test biologique vis-a-vis du diagnostic clinique, notamment la sensibilite et la specificite. A partir de ces deux criteres, elabores grâce a l'etude de populations bien definies (malades et temoins), on peut calculer les valeurs predictives positive et negative en tenant compte de la prevalence de la maladie. Alors, le resultat d'un test biologique pour un individu appartenant a un echantillonnage reel de consultants peut etre interprete comme normal ou pathologique en fonction de sa situation vis-a-vis de ces normes de reference.

Background Allergy to banana often occurs in patients sensitized to latex. The spectrum of IgE-mediated responses to latex allergens is more and more documented but banana allergens and epitopes shared by these two allergens have not yet been characterized, even though the existence of cross-reacting IgE antibodies has been demonstrated. Objective The purpose of this study was to assess the relationship between banana hypersensitivity and latex allergy in a population of 19 latex-allergic patients and to identify allergenic components in banana and the common structures shared with latex. Methods The in vivo study was conducted in our outpatient department in patients with well-documented latex allergy. Clinical histories were evaluated and skin prick tests were performed with banana and latex extracts. IgE responses from 19 patients were investigated by means of CAP RAST assay and SDS PAGE immunoblotting. Epitopes shared by banana and latex were investigated by means of immunoblotting experiments. Results Eight of 16 patients (50%) reported symptoms after eating bananas and banana skin prick tests were positive in 5 of 14 patients (36%). Banana RAST results were positive in 12 of the 19 patients (63%). In immunoblot experiments, 17 of the 19 patients (89%) exhibited specific banana IgE antibodies and 16 allergenic components were identified with molecular weights ranging from 17 to 128 kD. Two were considered as major allergens: 33 kD was detectable in 15 of 19 sera (88%) and 37 kD in 13 of 19 sera (76%). Inhibition studies by preincubation of two individual sera with banana or latex extract demonstrated the complete disappearance of IgE binding on banana blotted allergens. Conclusion This study confirms the "latex-fruit syndrome" already described by Blanco et al. Two major allergens were revealed in banana at 33 and 37 kD and the presence of more than ten common components with latex was observed.

Resume L'indication et l'interpretation du dosage serique des IgE et des IgG specifiques ainsi que du test d'histaminoliberation in vitro sont discutees comme elements de diagnostic de l'allergie aux venins d'hymenopteres. La place de ces tests dans le bilan conduisant a la mise en œuvre et au suivi d'une desensibilisation est evaluee.

Resume Phadiatop™ est un nouveau test biologique permettant le depistage de l'allergie respiratoire. Ce test, base sur le principe du RAST, utilise un disque de papier sur lequel est fixe un melange equilibre de pneumallergenes selectionnes. 105 enfants (4 mois — 15 ans) d'une consultation d'allergologie ont ete etudies. Il existe une bonne correlation entre ce nouveau test et le taux des IgE totales (70,5 %), des IgE specifiques (96,2 %) et les tests cutanes (95,2 %). La correlation entre le diagnostic clinique et les resultats du Phadiatop™ est hautement significative : efficacite 98,1 p. cent, sensibilite 96,1 p. cent et specificite 100 p. cent.