Time filter

Source Type

Le Touquet – Paris-Plage, France

Ciancanelli M.J.,Rockefeller University | Huang S.X.L.,Columbia University | Luthra P.,Mount Sinai School of Medicine | Garner H.,Kings College London | And 45 more authors.
Science | Year: 2015

Severe influenza disease strikes otherwise healthy children and remains unexplained.We report compound heterozygous null mutations in IRF7, which encodes the transcription factor interferon regulatory factor 7, in an otherwise healthy child who suffered life-threatening influenza during primary infection. In response to influenza virus, the patient's leukocytes and plasmacytoid dendritic cells produced very little type I and III interferons (IFNs). Moreover, the patient's dermal fibroblasts and induced pluripotent stem cell (iPSC)-derived pulmonary epithelial cells produced reduced amounts of type I IFN and displayed increased influenza virus replication.These findings suggest that IRF7-dependent amplification of type I and III IFNs is required for protection against primary infection by influenza virus in humans. They also show that severe influenza may result from single-gene inborn errors of immunity. © 2015, American Association for the Advancement of Science. All rights reserved. Source

Lim H.K.,Rockefeller University | Lim H.K.,French Institute of Health and Medical Research | Lim H.K.,University of Paris Descartes | Seppanen M.,Immunodeficiency Unit | And 36 more authors.
Neurology | Year: 2014

Objective: To determine the proportion of children with herpes simplex encephalitis (HSE) displaying TLR3 deficiency, the extent of TLR3 allelic heterogeneity, and the specific clinical features of TLR3 deficiency. Methods: We determined the sequence of all exons of TLR3 in 110 of the 120 patients with HSE enrolled in our study who do not carry any of the previously described HSE-predisposing mutations of TLR3 pathway genes (TLR3, UNC93B1, TRIF, TRAF3, and TBK1). All the new mutant TLR3 alleles detected were characterized experimentally in-depth to establish the causal relationship between the genotype and phenotype. Results: In addition to the 3 previously reported TLR3-deficient patients from the same cohort, 6 other children or young adults with HSE carry 1 of 5 unique or extremely rare (minor allele frequency ,0.001) missense TLR3 alleles. Two alleles (M374T, D592N) heterozygous in 3 patients are not deleterious in vitro. The other 3 are deleterious via different mechanisms: G743D1R811I and L360P heterozygous in 2 patients are loss-of-function due to low levels of expression and lack of cleavage, respectively, and R867Q homozygous in 1 patient is hypomorphic. The 3 patients' fibroblasts display impaired TLR3 responses and enhanced herpes simplex virus 1 susceptibility. Overall, TLR3 deficiency is therefore found in 6 (5%) of the 120 patients studied. There is high allelic heterogeneity, with 3 forms of autosomal dominant partial defect by negative dominance or haploinsufficiency, and 2 forms of autosomal recessive defect with complete or partial deficiency. Finally, 4 (66%) of the 6 TLR3-deficient patients had at least 1 late relapse of HSE, whereas relapse occurred in only 12 (10%) of the total cohort of 120 patients. Conclusions: Childhood-onset HSE is due to TLR3 deficiency in a traceable fraction of patients, in particular the ones with HSE recurrence. Mutations in TLR3 and TLR3 pathway genes should be searched and experimentally studied in children with HSE, and patients with proven TLR3 deficiency should be followed carefully. © 2014 American Academy of Neurology. Source

Crequer A.,Rockefeller University | Crequer A.,University of Paris Descartes | Picard C.,French Institute of Health and Medical Research | Picard C.,University of Paris Descartes | And 17 more authors.
Journal of Clinical Immunology | Year: 2013

Epidermodysplasia verruciformis (EV) is a rare genodermatosis characterized by persistent flat warts or pityriasis versicolor-like lesions caused by betapapillomaviruses (EV-HPVs). Autosomal recessive EVER1 and EVER2 deficiencies account for EV in most patients. The mechanisms by which mutations in these partners of the Zinc transporter ZnT1 impair host defense against EV-HPVs are still poorly understood. Keratinocytes of EVER-deficient patients display an alteration of zinc homeostasis and an enhanced proliferative activity. Since EVER proteins are highly expressed in T lymphocytes, we aimed to assess the impact of EVER2 deficiency on T-cell development and function. We studied circulating lymphocyte populations in three adult EV patients sharing the same EVER2 mutation (T150fsX3). We found a normal count of CD4+ and CD8+ T cells and a normal proliferative capacity in response to anti-CD3 stimulation. However, we observed a significant increase of memory CD4+ and effector memory CD8+ T cells, a bias of the TCR Vαβ and Vγδ repertoires and an increase of skin-homing CD4+ T-cell subsets. Our findings suggest that EVER2-deficient patients display mild T-cell abnormalities. It remains unclear whether these abnormalities result from EVER deficiency, chronic EV-HPV infection, or both. © Springer Science+Business Media, LLC 2012. Source

Frange P.,Pediatric Immuno Hematology Unit | Frange P.,University of Paris Descartes | Leruez-Ville M.,University of Paris Descartes | Leruez-Ville M.,Virology Laboratory | And 26 more authors.
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2014

Scarce data exist on allogeneic hematopoietic stem cell transplantation (HSCT) outcomes in hepatitis B virus (HBV)-naïve recipients from HBV-experienced donors. Long-term follow-up is herein reported for 17 allogeneic HSCT performed in 13 HBV-naïve children from HBc-antibodies-positive donors between 2006 and 2012. Four donors were HBs-antigen-positive, with detectable but low viremia in 2 cases (<2 log10IU/ml). HBV-DNA was undetectable in all transplanted cell products. Recipients' HBV prophylaxis consisted of pre-transplant vaccination, polyvalent immune globulins, specific anti-HBV immune globulins, and/or oral lamivudine in 3, 12, 8, and 8 children, respectively. No case of HBV transmission occurred based on negative close monitoring of recipients' HBV serology and plasma HBV-DNA during a median follow-up of 22 months. In case of undetectable viremia in the donor, prophylaxis with vaccination and/or immune globulins in the recipient seems to be sufficient and lamivudine prophylaxis might be unnecessary to prevent viral transmission. In case of undetectable viremia in the donor, a systematic screening of HBV DNA in the stem cell product might be unnecessary to confirm the low risk of viral transmission. Prior exposure to HBV in the donor should not be considered a contraindication to HSCT. © 2013 Springer-Verlag. Source

Prot-Labarthe S.,AP HP | Stil-Baudry J.,AP HP | Fahd M.,Pediatric Immuno Hematology Unit | Brion F.,AP HP | And 3 more authors.
Journal of Pediatric Hematology/Oncology | Year: 2013

INTRODUCTION:: The patients receiving hematopoietic stem cell transplantation (HSCT) require routine management: the role of the pharmacist has not been extensively considered. This study had 2 aims: to explore the knowledge of community pharmacists relating to pediatric HSCT and to evaluate their expectations in terms of training needs. MATERIALS AND METHODS:: We interviewed 40 community pharmacists in May and June 2010 in Paris (France) with a 3 parts questionnaire: information concerning the community pharmacy, analysis of 2 pediatric prescriptions and knowledge about HSCT and professional training. RESULTS:: Twenty-nine (72.5%) of the 40 community pharmacies agreed to participate in the study. When asked what pharmacological advice they would give for an episode of fever, 13% of the pharmacists asked said that they would deliver acetaminophen without asking any further questions. Concerning hypertrichosis in patients treated with corticosteroids and ciclosporin, none mentioned the role of ciclosporin. The erroneous indications for HSCT given included road accidents (1 pharmacist; 3.4%) and hemophilia (3 pharmacists; 10.3%). Almost 80% of the pharmacists questioned considered their HSCT knowledge insufficient for their professional practice. An E-learning session adapted to their needs was of interest to almost three quarters of the pharmacists questioned. Copyright © 2012 by Lippincott Williams & Wilkins. Source

Discover hidden collaborations