[Anaphylactic shock due to recombinant human insulin: follow-up of a desensitization protocol by basophil activation test]. / Choc anaphylactique à l'insuline humaine recombinante: suivi d'un protocole d'accoutumance par tests d'activation des basophiles.

INTRODUCTION: Despite the occurrence of a severe allergic reaction including an anaphylactic shock, a drug may remain essential and impossible to replace. This may be the case of insulin in a diabetic patient. We describe the case of an anaphylactic shock to human insulin in whom a desensitization protocol was successfully achieved. CASE REPORT: A 50-year-old type 2 diabetic man presented one year after initiation of the insulin therapy an anaphylactic shock following the subcutaneous administration of a human insulin containing protamine (Insulatard®). A desensitization protocol to human insulin was performed and allowed to use two human insulin analogues containing no protamine (asparte and glargine), with a two-year event-free follow-up. Positive skin tests with insulin and protamine, and the presence of insulin specific IgE were evidenced of an IgE-mediated mechanism. Desensitization was monitored by skin tests, Maunsell's test, measurement of specific IgE and IgG4, and the basophil activation test. The decrease of basophil sensitivity to insulin is an early marker for tolerance induction. CONCLUSION: The effectiveness of the desensitization to human insulin underlines the importance to define the modalities of such desensitization protocol and of the monitoring of the tolerance induction.

[Detection of colonization by Streptococcus agalactiae: prospective study comparing real-time gene amplification with a new chromogenic medium Strepto B ID]. / Détection de la colonisation par Streptococcus agalactiae: étude prospective comparant l'amplification génique en temps réel à un nouveau milieu chromogène Strepto B ID.

We carried out a prospective study including 554 vaginal swabs simultaneously tested for antenatal screening of Group B Streptococcus (GBS or Streptococcus agalactiae) using culture on the chromogenic medium Strepto B ID (Biomérieux, Marcy l'Etoile, France) and real time gene amplification on LightCycler (Roche Applied Science). We centrifuge the swabs with "SETS" device and separate centrifugates in 2 parts: one for the culture and the other one for molecular biology. First half of the centrifugate is inoculated onto Todd-Hewitt broth enriched with antibiotics. This broth is incubated to 35 degrees C during 24 hours and then subcultured on a Strepto B ID medium. This last one is incubated during 24 hours to 35 degrees C in capnophilic conditions before interpretation. DNA extraction for molecular biology is simply obtained by heating the microtubes to 95 degrees C in a water bath. The cfb gene is amplified, allowing a specific gene amplification of GBS even within a polymorphic flora. The concordance between both methods is 94.8%. The sensitivity and negative predictive values obtained are respectively 88.0 and 97.4% for real time PCR and 83.0 and 96.4% for culture on Strepto B ID. Both methods are thus concordant, with equal sensitivity and valid for detection of GBS colonization in pregnant women. However real time gene amplification allows reducing turn around time since molecular biology process (extraction+amplification) does not exceed 1 hour.

[Direct and fast detection of methicillin resistant Staphylococcus aureus carriage by automated nucleic acid extraction and real time PCR]. / Détection directe et rapide du portage de Staphylococcus aureus résistant à la méthicilline par extraction automatisée de l'acide nucléique et PCR en temps réel.

We have developed a real time PCR assay for methicillin resistant Staphylococcus aureus (MRSA) screening able to provide a result in less than 3 h. The PCR amplifies a 184 bp fragment corresponding to the junction area between mecA and orfX genes that allows specific identification of MRSA in a nonsterile specimen. 1481 nasal swabs taken from geriatrics, dialysis and intensive care patients were compared with traditional bacteriology. A short centrifugation, preliminary to the extraction, with "SETS" system allows a recovery of the sample. The automated DNA extraction is carried out by the MagNA Pure LC and the PCR by the LightCycler. The agreement between the two methods is 97.7%. A study of sensitivity and specificity on 1111 samples respectively gives 75 and 98% for the real time PCR and, 64 and 99% for the culture. The strategy of fast and effective tracking that we propose is of an undeniable contribution in the fight against the MRSA infections.

Impact of cryopreservation on B cell chronic lymphocytic leukaemia phenotype.

BACKGROUND AND OBJECTIVES: Freezing is a practical approach for cell preservation for retrospective studies. The aim of this work was to check the cryopreservation impact on B cell chronic lymphocytic leukaemia phenotype. MATERIAL AND METHODS: Blood samples from 15 CLL patients were analyzed freshly and after freezing at -196 degrees C, without separation, and thawing. Results were compared by Student's paired t-test. RESULTS: The phenotype of fresh CLL cells was as follows: CD19+, CD5+, faint CD20, CD23+/-, weak CD22 and sIg, CD37+, HLA-DR+, FMC7-. After cryopreservation, the percentage of CD5 and CD23 positive cells decreased, whereas HLA-DR positive cells increased moderately. The CLL Matutes's score was modified in 6 cases out of 15 (40%). CONCLUSION: Cryopreservation modifies B cell chronic lymphocytic leukaemia phenotype, by decreasing CD5 and CD23 expression.