Germline bi-allelic <i>SH2B3/LNK</i> alteration predisposes to a neonatal juvenile myelomonocytic leukemia-like disorder

Juvenile myelomonocytic leukemia (JMML) is a rare, generally aggressive myeloproliferative neoplasm affecting young children. It is characterized by granulomonocytic expansion, with monocytosis infiltrating peripheral tissues. JMML is initiated by mutations upregulating RAS signaling. Approximately 10% of cases remain without an identified driver event. Exome sequencing of 2 unrelated cases of familial JMML of unknown genetics and analysis of the French JMML cohort identified 11 patients with variants in SH2B3, encoding LNK, a negative regulator of the JAK-STAT pathway. All variants were absent from healthy population databases, and mutation spectrum was consistent with a loss of function of the LNK protein. A stoploss variant was shown to affect both protein synthesis and stability. The other variants were either truncating or missense, the latter affecting the SH2 domain that interacts with activated JAK. Of the 11 patients, 8 from 5 families inherited pathogenic bi-allelic SH2B3 germline variants from their unaffected heterozygous parents. These children represent half of the cases with no identified causal mutation in the French cohort. They displayed typical clinical and hematological JMML features with neonatal onset and marked thrombocytopenia. They were characterized by absence of additional genetic alterations and a hypomethylated DNA profile with fetal characteristics. All patients showed partial or complete spontaneous clinical resolution. However, progression to thrombocythemia and immunity-related pathologies may be of concern later in life. Bi-allelic SH2B3 germline mutations thus define a new condition predisposing to a JMML-like disorder, suggesting that the JAK pathway deregulation is capable of initiating JMML, and opening new therapeutic options

Purpura thrombopénique immunologique de l'enfant (intérêt pronostique du taux de plaquettes au J21)

Introduction: Le Purpura Thrombopénique Immunologique de l enfant (PTI) évolue favorablement dans 80% des cas. La forme chronique est définie par une thrombopénie inférieure à 100 000/mm3 pendant au moins 1 an. La recherche de critères orientant vers une forme chronique, comme le taux de plaquettes à J21, semble indispensable. Patients et méthodes: Nous avons mené une étude pédiatrique rétrospective, bi-centrique, sur des PTI aigus ou chroniques de 1996 à 2010. Des données personnelles et relatives à la maladie étaient recueillies dans les dossiers médicaux, des facteurs de risque de chronicité étaient recherchés. Résultats: Parmi les 181 patients inclus, 70,2% avaient une forme aiguë et 29,8%, une forme chronique. Ces derniers étaient plus âgés (p= 71 mois, un taux de plaquettes initial >= 12000/mm3, un taux de plaquettes à J21 = 71 month, initial platelet count >= 12000/mm3, platelets count at day 21 <115000/mm3, no treatment and no Ig perfusion. The platelets count at day 21 was the only one to be significant in multivariate analysis. Discussion: We showed that there are 2 different populations. Chronic ITP could be the beginning of a systemic disease like systemic lupus or autoimmune lymphoproliferative syndrom. Platelets count at day 21 less than 115 000/mm 3, could lead us to run other tests like anti DNA antibodies or double negative T lymphocytes. Conclusion: Early detection of chronic ITP with the platelets count at day 21 seems likely. This chronicity is probably not just the natural evolution of ITP but appears to be more complex.AMIENS-BU Santé (800212102) / SudocSudocFranceF

Salvage therapy with gemcitabine, vinorelbine, and pegylated liposomal doxorubicin for relapsed or refractory pediatric Hodgkin lymphoma. Results of a retrospective series of four children

International audienc

Optical Mapping, a Promising Alternative to Gold Standard Cytogenetic Approaches in Acute Lymphoblastic Leukemias: A Blind Comparison on 10 Patients

International audienc

Adherence to recommendations for the use of antifungal agents in a tertiary care hospital

OBJECTIVES: The aim of our study was to assess the adherence to labelling and international guidelines for antifungal prescribing. METHODS: A retrospective study was performed in intensive care units in addition to the oncology and haematology department, which covered 70% of antifungal consumption at Hautepierre Hospital, Strasbourg, France. On reviewing medical charts, the antifungal prescription was examined in relation to the recommendations of indication, dosage, risk of drug-drug interactions and, where appropriate, antifungal susceptibility testing. Treatments were considered appropriate, inappropriate or debatable. RESULTS: Between January and April 2007, 199 treatments were given for 179 different episodes in 133 adult patients. Treatments were prescribed for pre-emptive or targeted therapy (n = 90, with 60 for candidiasis, 26 for aspergillosis and 4 for other mould diseases), empirical therapy (n = 17) and primary (n = 81) or secondary (n = 11) prophylaxis. Fluconazole accounted for 67% of prescriptions, followed by voriconazole (19%), caspofungin (10%), posaconazole (2%), conventional or liposomal amphotericin B (2%), itraconazole (<1%) and terbinafine (<1%). Indication and dosage were found to be appropriate in 65% and 62% of cases, inappropriate in 22% and 21%, and debatable in 13% and 17%, respectively. The overall (by combining all assessment criteria) rate of inappropriate use was 40%. The overall survival rate at 12 weeks was highest in patients receiving appropriate therapy (81% versus 72% and 68% in the debatable and inappropriate therapy groups, respectively), with between-group differences not being significant (P = 0.49). CONCLUSIONS: Our evaluation revealed a high proportion of inappropriate or debatable use of antifungal agents, while highlighting significant issues, such as inadequate dosage or indications

Optical genome mapping, a promising alternative to gold standard cytogenetic approaches in a series of acute lymphoblastic leukemias

International audienceAcute lymphoblastic leukemias (ALL) are characterized by a large number of cytogenetic abnormalities of clinical interest that require the use of several complementary techniques. Optical genome mapping (OGM) is based on analysis of ultra-high molecular weight DNA molecules that provides a high-resolution genome-wide analysis highlighting copy number and structural anomalies, including balanced translocations. We compared OGM to standard techniques (karyotyping, fluorescent in situ hybridization, single nucleotide polymorphism-array and reverse transcription multiplex ligation-dependent probe amplification) in 10 selected B or T-ALL. Eighty abnormalities were found using standard techniques of which 72 (90%) were correctly detected using OGM. Eight discrepancies were identified, while 12 additional anomalies were found by OGM. Among the discrepancies, four were detected in raw data but not retained because of filtering issues. However, four were truly missed, either because of a low variant allele frequency or because of a low coverage of some regions. Of the additional anomalies revealed by OGM, seven were confirmed by another technique, some of which are recurrent in ALL such as LMO2-TRA and MYC-TRB fusions. Despite false positive anomalies due to background noise and a case of inter-sample contamination secondarily identified, the OGM technology was relatively simple to use with little practice. Thus, OGM represents a promising alternative to cytogenetic techniques currently performed for ALL characterization. It enables a time and cost effective analysis allowing identification of complex cytogenetic events, including those currently inaccessible to standard techniques

Optical genome mapping, a promising alternative to gold standard cytogenetic approaches in a series of acute lymphoblastic leukemias

International audienceAcute lymphoblastic leukemias (ALL) are characterized by a large number of cytogenetic abnormalities of clinical interest that require the use of several complementary techniques. Optical genome mapping (OGM) is based on analysis of ultra-high molecular weight DNA molecules that provides a high-resolution genome-wide analysis highlighting copy number and structural anomalies, including balanced translocations. We compared OGM to standard techniques (karyotyping, fluorescent in situ hybridization, single nucleotide polymorphism-array and reverse transcription multiplex ligation-dependent probe amplification) in 10 selected B or T-ALL. Eighty abnormalities were found using standard techniques of which 72 (90%) were correctly detected using OGM. Eight discrepancies were identified, while 12 additional anomalies were found by OGM. Among the discrepancies, four were detected in raw data but not retained because of filtering issues. However, four were truly missed, either because of a low variant allele frequency or because of a low coverage of some regions. Of the additional anomalies revealed by OGM, seven were confirmed by another technique, some of which are recurrent in ALL such as LMO2-TRA and MYC-TRB fusions. Despite false positive anomalies due to background noise and a case of inter-sample contamination secondarily identified, the OGM technology was relatively simple to use with little practice. Thus, OGM represents a promising alternative to cytogenetic techniques currently performed for ALL characterization. It enables a time and cost effective analysis allowing identification of complex cytogenetic events, including those currently inaccessible to standard techniques

Phytochemical characterisation and aromatic potential for brewing of wild hops (Humulus lupulus L.) from Northern France: Towards a lead for local hop varieties

peer reviewedIn the current context of developing aromatic beers, our study aims at deciphering the chemical characterisation of cones from 39 wild hop genotypes collected in the North of France and replanted in an experimental hop farm, as well as 10 commercial and 3 heirloom varieties, using HS-SPME/GC–MS for the volatile compounds, UHPLC-UV for phenolic compound quantification, and UHPLC-IMS-HRMS for untargeted metabolomics. These analyses revealed a strong opposition between wild accessions and reference varieties, and an original chemical composition of some genotypes. 27 beers were produced with the same recipe, analysed by SBSE-GC–MS and evaluated by panellists. The unique difference relates to the hops to be assessed in order to determine their sensory profile. The different datasets were compared by OPLS-DA analysis in order to identify chemical markers which may influence the hop aromatic potential. Our results highlight the aromatic potential of some wild accessions, close to the commercial variety Cascade

Circulating cell-free BRAF V600E as a biomarker in children with Langerhans cell histiocytosis

International audienceThe BRAFV600E mutation is reported in half of patients with Langerhans cell histiocytosis (LCH). This study investigated the detection of the BRAFV600E allele in circulating cell-free (ccf) DNA in a paediatric LCH cohort. Children with BRAFV600E -mutated LCH were investigated to detect ccf BRAFV600E at diagnosis (n = 48) and during follow-up (n = 17) using a picolitre-droplet digital PCR assay. At diagnosis, ccf BRAFV600E was positive in 15/15 (100%) patients with risk-organ positive multisystem (RO+ MS) LCH, 5/12 (42%) of patients with RO- MS LCH and 3/21 (14%) patients with single-system (SS) LCH (P < 0·001, Fisher's exact test). The positive BRAFV600E load was higher for RO+ patients (mean, 2·90%; range, 0·04-11·4%) than for RO- patients (mean, 0·16%; range, 0·01-0·39) (P = 0·003, Mann-Whitney U test). After first-line vinblastine-steroid induction therapy, 7/7 (100%) of the non-responders remained positive for ccf BRAFV600E compared to 2/4 (50%) of the partial-responders and 0/4 of the complete responders (P = 0·002, Fisher's exact test). Six children treated with vemurafenib showed a clinical response that was associated with a decrease in the ccf BRAFV600E load at day 15. Thus, ccf BRAFV600E is a promising biomarker for monitoring the response to therapy for children with RO+ MS LCH or RO- LCH resistant to first-line chemotherapy

Long-term follow-up of children with risk organ-negative Langerhans cell histiocytosis after 2-chlorodeoxyadenosine treatment

International audienceThe nucleoside analogue, 2-chlorodeoxyadenosine (2CDA), was reported to be an active treatment for childhood Langerhans cell histiocytosis (LCH) without risk organ (RO−) involvement. However, we lack data on long-term effects of 2CDA treatment, including the disease reactivation rate, permanent sequelae and long-term tolerance. This study included 44 children from the French LCH registry, treated for a RO− LCH with 2CDA monotherapy (median number of six courses). The median age at the beginning of 2CDA was 3·6 years (range, 0·3–19·7 years) and the median follow-up after was 5·4 years (range, 0·6–15·1 years). Objective response to 2CDA was observed in 25 patients (56·8%), while six patients (13·6%) had stable disease and 13 patients (29·5%) exhibited progressive disease. Among patients without progression, only two experienced disease reactivation after 2CDA discontinuation. The five-year cumulative incidence of disease progression or reactivation after 2CDA therapy initiation was 34·3%. The lymphopenia reported in all cases [72% below absolute lymphocyte count (ALC) of 0·5 G/l], was addressed with appropriate prophylactic measures. Other toxicities above grade 2 were uncommon, and no second malignant neoplasm or neuropathy was reported. The five-year overall survival was 97·7%. In conclusion, we could confirm that 2CDA monotherapy was a beneficial long-term therapy for treating patients with RO− LCH. Appropriate management of induced immune deficiency is mandatory