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Summary Background To confirm allergy to b-lactam (BL), a basophil activation test in flow cytometry based on CD63 up-regulation was described. CD203c is a more recent basophil activation marker and up to day there is no consensus about which marker is the more sensitive one. CD203c has not yet been evaluated in the diagnosis of BL allergy. Objective The aim of the study was to compare the reliability of CD203c to CD63 for the diagnosis of amoxicillin (AX) allergy, which is nowadays the most frequent BL allergy. Methods Twenty-seven patients with an immediate positive skin test (ST) to AX, 20 had had anaphylaxis with AX and 7 had urticaria and/or angioedema, were compared with 14 controls with no allergy to BL and to six patients with delayed positive ST to AX. Results In the anaphylaxis group, AX induced up-regulation of CD203c in the basophils of 12 patients out of 20 (60%) and of CD63 in four patients (20%) (Po0.02). Two patients out of seven with urticaria or angioedema had a positive result with CD203c and CD63. In patients who had anaphylaxis, ampicillin (AMP) induced CD203c up-regulation in eight out of 12 (67%) patients tested, and CD63 up-regulation in 4 out of 12 (33%) (all patients who had anaphylaxis could not be tested with AMP). False-positive results were observed with CD203c as well as CD63, and for 10 patients indeed this was confirmed by a negative drug provocation test. The origin of conflicting results between CD63 and CD203c might be at least the targeting of basophils based on anti-IgE labelling. Among IgE 1 gated cells, by means of CD33, a marker of monocytes, a contamination up to 50% by monocytes was detected. In contrast to CD63, CD203c is an activation marker specific of basophils with a basal low-level expression in resting basophils. Thus, IgE and CD203c double targeting of basophils avoids the contamination by monocytes. Conclusion CD203c seems to be a more sensitive activation marker of basophils than CD63 for the diagnosis of amoxicillin allergy.

Background. An in vitro basophil activation test, based on the detection of CD63 upregulation induced by NSAIDs, has been described. Its clinical significance remains controversial. Objectives. In patients with a history of nonallergic NSAID hypersensitivity, stratified according to the severity of the symptoms, to assess with NSAIDs the predictive value of basophil (BAT) and monocyte (MAT) activation tests. Patients/Methods. Sixty patients who had NSAIDs-induced or exacerbated urticaria/angiooedema and 20 controls was included. After incubation with NSAIDs or acetaminophen, leukocytes were analysed for CD63 upregulation. Results. With aspirin, the sensitivity (37%) and specificity (90%) of BAT agree with already published results. In contrast, when patients had had cutaneous and visceral reactions, the frequency of positive BAT 14/22 (64%, P<0.001) or MAT 10/22 (46%, P<0.01) were increased. Conclusions. Positive tests were more frequent among patients having a severe hypersensitivity contrasting with the other patients who had results similar to controls.

Introduction Le bleu patente (BP) est un colorant des voies lymphatiques utilise pour le reperage du ganglion sentinelle, pouvant etre responsable de reactions d’hypersensibilite immediate. Methodes Nous avons mene une etude retrospective en incluant tous les patients testes au BP dans le service de dermato-allergologie de l’hopital Tenon. L’objectif de cette etude etait d’etudier l’interet des tests cutanes. Resultats Seize femmes etaient adressees pour suspicion de reaction allergique au BT. Quatorze patientes avaient presente des reactions d’allure allergique lors du reperage du ganglion sentinelle par le BP au cours d’une anesthesie generale. Deux des 16 patientes n’avaient jamais recu de BP : une etait testee en prevention avant une injection de BP pour reperage du ganglion sentinelle et une autre en raison d’une suspicion d’allergie au bleu indigo. Les manifestations cliniques etaient variees : choc anaphylactique dont deux arrets cardiaques (n = 10), urticaire generalisee dont deux urticaires bleutees (n = 4). Le delai des reactions, precise chez quatre des patients, etait de moins de dix minutes apres injection de BP. Quatorze patientes ont eu successivement des prick-tests et des tests intradermiques avec des concentrations progressivement croissantes au BP et aux produits anesthesiques. Le latex etait aussi teste. Treize de ces 14 patientes avaient des tests positifs pour le BP, contre indiquant definitivement cette molecule. Une des patientes avait un test negatif au BP mais positif au suxamethonium. Les 2 patientes n’ayant jamais eu d’injection de BP avaient des tests negatifs. Une patiente sur les 6 testees au bleu de methylene avait egalement un test positif a ce colorant. Discussion Nos resultats soulignent l’interet des tests cutanes au BP dans l’exploration de reactions d’hypersensibilites immediates. Les tests au BP ne semblent pas irritants aux concentrations utilisees car trois patientes dont une exposee au BP avaient des tests negatifs. Des cas de co-sensibilisation au BP et bleu de methylene ont ete rapportes dans la litterature comme chez une de nos patiente, incitant a la prudence vis-a-vis de ce colorant. Conclusion Dans cette etude, les tests cutanes ont permis de confirmer une reaction allergique au BP.

Les tests cellulaires pour l’explorationin vitro de l’hypersensibilite immediate, utilisent le polynucleaire basophile du sang peripherique. Ce leucocyte qui possede la plupart des proprietes du mastocyte, un recepteur membranaire de forte affinite pour les IgE (FceR1) et des granulations contenant des mediateurs preformes de l’anaphylaxie, est un bon temoin de la sensibilisation mastocytaire contre un allergene. Mais comme ce dernier est d’un acces difficile, pour les etudesin vitro chez l’homme on prefere travailler sur le basophile.

An autoantibody to liver cytosol was previously described in childhood autoimmune chronic active hepatitis type 2. The antigen, liver cytosol antigen type 1, was for the first time partially purified using gel filtration and ion exchange chromatography, and it was characterized using immunodiffusion, immunoblot and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the immunoprecipitate. Immunoblot detected a unique antigenic peptide at 62 kD from human cytosol and at 58 kD from rat cytosol. The same peptides were also detected when immunoprecipitates of liver cytosol antigen type 1 and autoantibodies to liver cytosol antigen were submitted to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A polymeric structure, probably a tetramer, is suggested for native liver cytosol antigen type 1 because in gel filtration chromatography liver cytosol antigen type 1 was eluted as a protein of a molecular weight between 240 and 290 kD when human liver cytosol was fractionated and between 220 and 270 kD from rat liver cytosol. Liver cytosol antigen type 1 is probably poor in carbohydrates because it was not stained by periodic acid-Schiff stain. The autoantibodies to liver cytosol were frequently found in association with antiliver kidney microsomal autoantibodies type 1, which are directed against the cytochrome P-450 of the IID6 subfamily. Antiliver kidney microsomal autoantibodies type 1 but not antiliver cytosol autoantibodies were found in association with antibodies to hepatitis C virus. Autoantibodies to liver cytosol antigen type 1 seem to be a more specific marker for autoimmune hepatitis type 2 than antiliver kidney microsomal antibodies type 1 autoantibodies.

In stimulated cultures, a proportion of human T lymphocytes form multilayer rosettes with sheep red blood cells (SRBC) and they can be easily separated from common E rosettes by velocity sedimentation. We have developed a simplified method for harvesting multilayer rosettes and quantifying them. Practical applications of this technique are discussed.