A novel immunoassay using recombinant allergens simplifies peanut allergy diagnosis.

BACKGROUND: Double-blind placebo-controlled food challenge (DBPCFC) is currently considered the gold standard for peanut allergy diagnosis. However, this procedure that requires the hospitalization of patients, mostly children, in specialized centers for oral exposure to allergens may cause severe reactions requiring emergency measures. Thus, a simpler and safer diagnosis procedure is needed. The aim of this study was to evaluate the diagnostic performance of a new set of in vitro blood tests for peanut allergy. METHODS: The levels of IgE directed towards peanut extract and recombinant peanut allergens Ara h 1, Ara h 2, Ara h 3, Ara h 6, Ara h 7, and Ara h 8 were measured in 3 groups of patients enrolled at 2 independent centers: patients with proven peanut allergy (n=166); pollen-sensitized subjects without peanut allergy (n=61), and control subjects without allergic disease (n=10). RESULTS: Seventy-nine percent of the pollen-sensitized patients showed IgE binding to peanut, despite their tolerance to peanut. In contrast, combining the results of specific IgE to peanut extract and to recombinant Ara h 2 and Ara h 6 yielded a peanut allergy diagnosis with a 98% sensitivity and an 85% specificity at a positivity threshold of 0.10 kU/l. Use of a threshold of 0.23 kU/l for recombinant Ara h 2 increased specificity (96%) at the cost of sensitivity (93%). CONCLUSION: A simple blood test can be used to diagnose peanut allergy with a high level of precision. However, DBPCFC will remain useful for the few cases where immunological and clinical observations yield conflicting results.

Eosinophil counts in upper digestive mucosa of Western European children: variations with age, organs, symptoms, Helicobacter pylori status, and pathological findings.

AIM: The aim of the study was to measure the number of eosinophils per high-power field (eos/HPF) according to age, organs, and clinical symptoms and to compare the results to histological characteristics of the upper digestive tract mucosa in children. PATIENTS AND METHODS: A systematic prospective assessment of 284 esophagus, 342 antrum, 453 corpus, and 167 duodenum biopsies was carried out in 316 girls and 366 boys referred for endoscopy (median age 9 months), eos/HPF, and histological analysis. RESULTS: Counts (mean-max SD) were as follows: esophagus 1.73 to 50 eos/HPF (5.35), antrum 3.27 to 40 (4.7), corpus 2.11 to 38 (3.76), and duodenum 4.80 to 46 (7.7). Counts >15 eos/HPF were found in 2.8% esophagi, 3.5% corpora, 4.9% antra, and 10.7% duodena. Duodenal eos/HPF were significantly higher than those of esophageal, corporeal, and antral. Mucosal eos/HPF increased with age in esophagus and antrum. The highest esophageal eos/HPF were significantly associated with recurrent abdominal pain, and with anemia in antrum, corpus, and duodenum. Major and/or minor histological features of eosinophilic esophagitis were seen in 9 of 10 esophagi with 5 to 15 eos/HPF and 7 of 8 esophagi with >15 eos/HPF. Eosinophils per high-power field were significantly correlated with histological antral and corporeal gastric inflammation. Helicobacter pylori-positive children had higher eosinophils per high-power field than H pylori negative ones both in esophagus and in antrum. CONCLUSIONS: The present study shows that in a western European country mucosal hypereosinophilia is rare. Mucosal eosinophil counts increase from esophagus to duodenum, and also with age in esophagus and antrum. The highest eos/HPF in the esophagus are associated with recurrent abdominal pain and in the corpus, antrum, and duodenum with anemia. Features of eosinophilic esophagitis are rare but detectable in association with counts as low as 6 eos/HPF.

In French children, primary gastritis is more frequent than Helicobacter pylori gastritis.

The aim of this study was to analyze the histological characteristics according to the updated Sydney classification (intensity of gastritis, degree of activity, gastric atrophy, intestinal metaplasia, and Helicobacter pylori) in symptomatic children referred for upper gastrointestinal endoscopy. A 4-year retrospective descriptive study was carried out in 619 children (282 females and 337 males), median age 3.75 years (15 days to 17.3 years) referred for endoscopy. Six gastric biopsies were done (three antrum and three corpus) for histological analysis (n = 4), direct examination and H. pylori culture (n = 2). H. pylori status was considered positive if at least two out of three tests were positive and negative if all three tests were negative. The results showed that only 66 children (10.66%) were H. pylori positive. Histological antral and corpus gastritis was detected in, respectively, 53.95% and 59.12% of all cases, most of them of mild grade 1. Antral and corpus activity was grade 1 in 18.57% and 20.03% of cases. H. pylori-positive versus H. pylori-negative children did differ in terms of moderate and marked histological gastritis and grade 2 or 3 activities. One girl had moderate gastric atrophy and another one moderate intestinal metaplasia, both being H. pylori negative. The findings indicate that primary antrum and corpus gastritis is 5.3 and 6.9 times, respectively, more frequent than H. pylori gastritis in French children, with usually mild histological gastritis and activity. Gastric atrophy and intestinal metaplasia are rare.

Fast-electron transport and heating of solid targets in high-intensity laser interactions measured by K alpha fluorescence.

We present experimental results on fast-electron energy deposition into solid targets in ultrahigh intensity laser-matter interaction. X-ray K alpha emission spectroscopy with absolute photon counting served to diagnose fast-electron propagation in multilayered targets. Target heating was measured from ionization-shifted K alpha emission. Data show a 200 microm fast-electron range in solid Al. The relative intensities of spectrally shifted Al K alpha lines imply a mean temperature of a few tens of eV up to a 100 microm depth. Experimental results suggest refluxing of the electron beam at target rear side. They were compared with the predictions of both a collisional Monte Carlo and a collisional-electromagnetic, particle-fluid transport code. The validity of the code modeling of heating in such highly transient conditions is discussed.

[Incidence and risk factors of HCV infection in a cohort of intravenous drug users in the North and East of France]. / Incidence et facteurs de risque de la séroconversion au virus de l'hépatite C dans une cohorte d'usagers de drogue intraveineux du nord-est de la France.

BACKGROUND: In order to evaluate the incidence and risk factors of infection by hepatitis C virus (HCV) among intravenous drug users we conducted a prospective cohort study of HCV and HIV negative IVDU in the North and East of France. METHODS: Two hundred and thirty-one IVDU who had injected drug at least once in their lifetime and were negative for anti-HCV and anti-HIV were followed-up every three months over a 12-month period. Serum anti-HCV and anti-HIV antibodies were tested at inclusion in the study and at the end of the follow-up. Data on injection practices and behaviours were collected at inclusion and at each visit, and a test for anti-HCV antibodies was performed on a saliva sample. When this proved positive, an ELISA test for serum anti-HCV antibodies was carried out. RESULTS: Of the 231 participants included, 165 (71.4%) underwent a final HCV and HIV serum test. The incidence was nil for HIV infection and 9% (95% CI: 4.6-13.4) person-years for HCV infection. Among IVDU who injected at least once during the last 6 months HCV infection incidence was 11% (95% CI: 4.7-17.1) person-years. The multivariate analysis carried out on the inclusion data found female sex alone to be an independent predictive factor of HCV seroconversion. In a Cox proportional hazard multivariate analysis that took into account time-dependent exposures and covariates, we found that syringe and cotton sharing were, after adjusting for other covariates, the only independent predictive factors of HCV seroconversion: hazard ratio: 6.3 [corrected] (95% CI: 1.1-35.4; [corrected] p<0.05) and 16.4 (95% CI: 1.4-190.6; [corrected] p<0.05), respectively. CONCLUSION: The transmission of the HCV virus persists among French IVDU despite an ongoing national harm reduction program. Injecting material and cotton sharing are the two major determinants of transmission in this cohort.

Clinical severity and molecular characteristics of circulating and emerging rotaviruses in young children attending hospital emergency departments in France.

Group A rotavirus (RVA) is the leading cause of acute gastroenteritis in young children worldwide. A prospective surveillance network has been set up to investigate the virological and clinical features of RVA infections and to detect the emergence of potentially epidemic strains in France. From 2009 to 2014, RVA-positive stool samples were collected from 4800 children <5 years old attending the paediatric emergency units of 16 large hospitals. Rotaviruses were then genotyped by RT-PCR with regard to their outer capsid proteins VP4 and VP7. Genotyping of 4708 RVA showed that G1P[8] strains (62.2%) were predominant. The incidence of G9P[8] (11.5%), G3P[8] (10.4%) and G2P[4] (6.6%) strains varied considerably, whereas G4P[8] (2.7%) strains were circulating mostly locally. Of note, G12P[8] (1.6%) strains emerged during the seasons 2011-12 and 2012-13 with 4.1% and 3.0% prevalence, respectively. Overall, 40 possible zoonotic reassortants, such as G6 (33.3%) and G8 (15.4%) strains, were detected, and were mostly associated with P[6] (67.5%). Analysis of clinical records of 624 hospitalized children and severity scores from 282 of them showed no difference in clinical manifestations or severity in relation to the genotype. The relative stability of RVA genotypes currently co-circulating and the large predominance of P[8] type strains may ensure vaccine effectiveness in France. The surveillance will continue to monitor the emergence of new reassortants that might not respond to current vaccines, all the more so as all genotypes can cause severe infections in infants.

Pharmacokinetics of oral acetylcysteine: absorption, binding and metabolism in patients with respiratory disorders.

The fate of an oral 100 mg dose of 35S-acetylcysteine, a mucolytic agent, was studied in 10 patients with respiratory disorders, 5 of whom underwent pneumonectomy or lobectomy a few hours after administration of the drug. In the 5 nonoperated patients, plasma radioactivity concentrations were maximal after 2 to 3 hours and remained high after 24 hours; about 22% of radioactivity was excreted in urine after 24 hours. In the 5 operated patients, plasma radioactivity concentrations were comparable with those in the nonoperated patients. Lung tissue radioactivity concentrations after 5 hours were comparable with those in plasma, while the presence of small amounts of radioactivity in the bronchial secretions indicates that acetylcysteine passes into the mucus. Total radioactivity after 5 hours consisted of free, unchanged drug and metabolites (about 22% of total in plasma, 48% in lung tissue), unchanged drug bound to protein by means of labile disulphide bridges (about 14% in plasma, 47% in lung tissue), and drug firmly bound to protein (about 64% in plasma, 5% in lung tissue). Oral acetylcysteine is rapidly absorbed and slowly excreted and is available in the lung in an active form for at least 5 hours at high concentrations.

[Primary infected aneurysm of the infra-renal aorta:in situ or extra-anatomic bypass?]. / Anévrisme primitivement infecté de l'aorte sous-rénale. Pontage extra anatomique ou in situ?

There is no agreement in the literature as regards the best treatment for primary infected aneurysms. There is agreement concerning in situ treatment, inlay graft for supra-renal aneurysms. For infra-renal localizations no consensus has been reached. Most Authors prefer biological grafts over prosthetic materials for infected grafts or primary infected aneurysms. We report here a case of primary infected aneurysm treated in two stages. An initial axillo-bifemoral bypass was followed one Month later by aneurysmectomy and wide debridement of infected tIssue. Results were good at two years.

[Toxoplasmosis serodiagnosis: comparison of Access Toxo IgM II assay compared to Axsym Toxo IgM and Vidas Toxo IgM assays]. / Sérodiagnostic de le toxoplasmose: comparaison de la trousse Access Toxo IgM II aux trousses Axsym Toxo IgM et Vidas Toxo IgM.

The Access Toxo IgM II test (Beckman Coulter Inc) was evaluated on 1,190 samples from toxoplasmosis serology requests, documented seroconversions, umbilical cord blood or venous blood from healthy newborn, and from newborns with congenital toxoplasmosis. Results were compared to those obtained with Vidas (bioMérieux) and Axsym (Abbott) assays, with Isaga as confirmatory technique. Results obtained with the Access test well correlate those with the Vidas (98.3%) and the Axsym (97.6%) assays. Less "bordeline" results are also observed with the Access test (0.22% versus 0.56% and 1.24% with Vidas and Axsym assays respectively). Results obtained from seroconverted patients prove that the Access assay is more sensitive than Vidas and Axsym assays, with respectively 2 and 4 samples detected earlier for 28 cases studied (recently seroconverted patients). Results obtained using prospective samples and with sequential sera obtained from patients with seroconversion clearly demonstrate that Access Toxo IgM II assay is perfectly adapted to toxoplasmosis diagnosis.

[Antigens of Toxoplasma gondii with a diagnostic and potential immunoprophylactic value: new strategies of identification]. / Antigènes de Toxoplasma gondii d'intérêt diagnostique et immunoprophylactique potentiel: nouvelles stratégies d'identification.

Toxoplasma gondii is an ubiquitous protozoan parasite which induces severe pathology in in utero infected children and in immunosuppressed patients (particularly in the case of AIDS). Previous work that focused on toxoplasma somatic antigens failed to demonstrate an efficient protection against highly virulent T. gondii strains. The authors therefore first studied the role of parasite excreted-secreted (ES) antigens in the immune response. They describe here the preparation of excreted-secreted antigens in cell-free medium from tachyzoites, the intracellular proliferative stage present during acute infection. Major ES antigens have Mr of 108 K, 97 K, 86 K, 57 K, 42 K, 39 K, 28.5 K, 27 K and 21 K. The protective role of ES antigens has been demonstrated using congenitally athymic (Nu/Nu) rats that are highly sensitive to T. gondii infection (+/+ Fischer rats are resistant). The humoral and cellular components of this protection have been studied by the passive transfer either of sera or of T lymphocytes from ES-immunized +/+ Fischer rats into Nu/Nu rats. Adoptive transfers were carried out 24 hours before infection with the highly virulent T. gondii RH strain. Based on the concept of concomitant immunity, the authors have characterized antigens from tachyzoites and bradyzoites (the encysted stage persisting during chronic infection) which share common epitopes. Four tachyzoite antigens, P63, GP43, P39 and GP 28.5 have been shown by immunoprecipitation to cross-react with bradyzoite antigens. Two monoclonal antibodies raised against ES antigens permitted to demonstrate the localization of the 28.5 K and 27 K antigens inside the dense granules of tachyzoites and bradyzoites.(ABSTRACT TRUNCATED AT 250 WORDS)

[Rapid identification of pneumococcal antigenes in urines by the Now Streptococcus pneumoniae Binax test]. / Détection rapide des antigènes pneumococciques urinaires par le test Now Streptococcus pneumoniae Binax.

Streptococcus pneumoniae is responsible for many infectious conditions but probably with an underestimated incidence especially because of the fragility of the bacteria. The present study has evaluated a new test which detects a pneumococcal antigen in urine (Now S.p Binax). Urine samples from 181 children and 40 adults have been tested. All the patients presented with typical clinical signs of pneumococcal infection. Sensitivity = 91.7 %; specificity = 54.2 %; positive predictive value = 50 %; and negative predictive value = 92.9 % have been observed. Although the sensitivity and specificity were lower than those announced by the manufacturer, the test is easy to handle and provides a rapid argument for the diagnosis of pneumococcal infection, especially in the case of invasive infections like meningitis and bacteraemia.

[Septic shock due to congenital disseminated toxoplasmosis?]. / Toxoplasmose congénitale disséminée responsable d'un choc septique?

Congenital toxoplasmosis secondary to maternal primary infection acquired late during pregnancy is generally asymptomatic at birth. We report a case of a newborn infant whose mother had been infected between the 27th and the 33rd week of gestation. No treatment had been given during gestation. The infant had a disseminated form of toxoplasmosis with hepatosplenomegaly, pneumonitis, purpura, hepatitis. On the third day of life, he developed shock. The patient died early despite therapy. Septic shock is unusual in congenital toxoplasmosis, although it has been described in immunocompromised patients, notably in patients infected with the human immunodeficiency virus.

A prospective study of nosocomial-infection-related mortality assessed through mortality reviews in 14 hospitals in Northern France.

AIM: To determine the number of deaths associated with nosocomial infection (NI) occurring in French hospitals, and to evaluate the role of hospital mortality reviews in assessing the preventability of NI-associated death. METHODS: The study considered 13,537 consecutive deaths occurring in 14 French hospitals in 2007 and 2008. An expert commission including attending physicians and nurses determined the likelihood that deaths could be attributed to NI, and the preventability of NI and death. FINDINGS: Medical records of the 2355 eligible patients with a McCabe score of 0 or 1 who died more than 48 h after admission were reviewed. Among them, 33% had at least one NI. Death was attributable to NI in 182 patients, and was considered preventable in 35 cases. Among these, 10 deaths were unexpected. CONCLUSION: Extrapolating these figures nationally, approximately 3500 [95% confidence interval (CI) 2605-4036] deaths attributable to NI occur in France annually. Among these, approximately 1300 NIs (95% CI 357-2196) and 800 deaths (95% CI 51-1481) can be considered preventable. Hospital mortality review commissions can help to improve the quality of health care by identifying circumstances associated with NI contributing to death, and targeting specific preventative measures. Such hospital commissions should involve all healthcare personnel.