Nozomu Kawashima

Paroxysmal nocturnal hemoglobinuria and telomere length predicts response to immunosuppressive therapy in pediatric aplastic anemia

Acquired aplastic anemia is an immune-mediated disease characterized by severe defects in stem cell number resulting in hypocellular marrow and peripheral blood cytopenias. Minor paroxysmal nocturnal hemoglobinuria populations and a short telomere length were identified as predictive biomarkers of immunosuppressive therapy responsiveness in aplastic anemia. We enrolled 113 aplastic anemia patients (63 boys and 50 girls) in this study to evaluate their response to immunosuppressive therapy. The paroxysmal nocturnal hemoglobinuria populations and telomere length were detected by flow cytometry. Forty-seven patients (42%) carried a minor paroxysmal nocturnal hemoglobinuria population. The median telomere length of aplastic anemia patients was −0.99 standard deviation (SD) (range −4.01–+3.01 SD). Overall, 60 patients (53%) responded to immunosuppressive therapy after six months. Multivariate logistic regression analysis identified the absence of a paroxysmal nocturnal hemoglobinuria population and a shorter telomere length as independent unfavorable predictors of immunosuppressive therapy response at six months. The cohort was stratified into a group of poor prognosis (paroxysmal nocturnal hemoglobinuria negative and shorter telomere length; 37 patients) and good prognosis (paroxysmal nocturnal hemoglobinuria positive and/or longer telomere length; 76 patients), respectively. The response rates of the poor prognosis and good prognosis groups at six months were 19% and 70%, respectively (P<0.001). The combined absence of a minor paroxysmal nocturnal hemoglobinuria population and a short telomere length is an efficient predictor of poor immunosuppressive therapy response, which should be considered while deciding treatment options: immunosuppressive therapy or first-line hematopoietic stem cell transplantation. The trial was registered in www.umin.ac.jp with number UMIN000017972.

GATA2 and secondary mutations in familial myelodysplastic syndromes and pediatric myeloid malignancies

GATA2, a member of the GATA transcription factor family, plays a critical role in hematopoiesis,1 vascular2 and neural development. Mutations in the exons and intron 5 of this gene have been identified as the cause of several hematologic disorders.3 GATA2-related disorders include familial myelodysplastic syndromes (MDS)/acute myeloid leukemia (AML);4,5 chronic myeloid leukemia (CML);6 monocytopenia and mycobacterial infection (MonoMAC) syndrome;7 and dendritic cell, monocyte, B and NK lymphoid (DCML) deficiency.8 Patients with MonoMAC syndrome or DCML deficiency exhibit increased susceptibility to infection and often progress to MDS and AML.2,8 Because GATA2 is associated with the development of vascular and lymphatic systems, patients with GATA2 deficiency may present with lymphedema, monosomy 7, and MDS, known as Emberger syndrome.2,9

Peripheral blood lymphocyte telomere length as a predictor of response to immunosuppressive therapy in childhood aplastic anemia

Predicting the response to immunosuppressive therapy could provide useful information to help the clinician define treatment strategies for patients with aplastic anemia. In our current study, we evaluated the relationship between telomere length of lymphocytes at diagnosis and the response to immunosuppressive therapy in 64 children with aplastic anemia, using flow fluorescence in situ hybridization. Median age of patients was ten years (range 1.5–16.2 years). Severity of the disease was classified as very severe in 23, severe in 21, and moderate in 20 patients. All patients were enrolled in multicenter studies using antithymocyte globulin and cyclosporine. The response rate to immunosuppressive therapy at six months was 52% (33 of 64). The probability of 5-year failure-free survival and overall survival were 56% (95% confidence interval (CI): 41–69%) and 97% (95%CI: 87–99%), respectively. Median telomere length in responders was −0.4 standard deviation (SD) (−2.7 to +3.0 SD) and −1.5 SD (−4.0 to +1.6 (SD)) in non-responders (P<0.001). Multivariate analysis showed that telomere length shorter than −1.0 SD (hazard ratio (HR): 22.0; 95%CI: 4.19–115; P<0.001), platelet count at diagnosis less than 25×109/L (HR: 13.9; 95%CI: 2.00–96.1; P=0.008), and interval from diagnosis to immunosuppressive therapy longer than 25 days (HR: 4.81; 95%CI: 1.15–20.1; P=0.031) were the significant variables for poor response to immunosuppressive therapy. Conversely to what has been found in adult patients, measurement of the telomere length of lymphocytes at diagnosis is a promising assay in predicting the response to immunosuppressive therapy in children with aplastic anemia.

Clinical utility of next-generation sequencing for inherited bone marrow failure syndromes

Purpose:Precise genetic diagnosis of inherited bone marrow failure syndromes (IBMFS), a heterogeneous group of genetic disorders, is challenging but essential for precise clinical decision making.Methods:We analyzed 121 IBMFS patients using a targeted sequencing covering 184 associated genes and 250 IBMFS patients using whole-exome sequencing (WES).Results:We achieved successful genetic diagnoses for 53 of 121 patients (44%) using targeted sequencing and for 68 of 250 patients (27%) using WES. In the majority of cases (targeted sequencing: 45/53, 85%; WES: 63/68, 93%), the detected variants were concordant with, and therefore supported, the clinical diagnoses. However, in the remaining 13 cases (8 patients by target sequencing and 5 patients by WES), the clinical diagnoses were incompatible with the detected variants.Conclusion:Our approach utilizing targeted sequencing and WES achieved satisfactory diagnostic rates and supported the efficacy of massive parallel sequencing as a diagnostic tool for IBMFS.Genet Med advance online publication 19 January 2017

Virological analysis of inherited chromosomally integrated human herpesvirus-6 in three hematopoietic stem cell transplant patients.

We analyzed 3 hematopoietic stem cell transplant (HSCT) recipients with inherited chromosomally integrated human herpesvirus‐6 (inherited CIHHV‐6). Cases 1 (inherited CIHHV‐6A) and 2 (inherited CIHHV‐6B) were inherited CIHHV‐6 recipients. Case 3 received bone marrow from a donor with inherited CIHHV‐6B. Following HSCT, HHV‐6B was isolated from Case 1. HHV‐6A and ‐6B messenger RNAs were detected in Cases 1 and 3.

Choreito, a formula from Japanese traditional medicine (Kampo medicine), for massive hemorrhagic cystitis and clot retention in a pediatric patient with refractory acute lymphoblastic leukemia

Hemorrhagic cystitis is critical in patients with hemato-oncological disorders. Unlike adult patients, there are limited modalities and invasive procedures are often not well tolerated in children with poor general conditions. We report a pediatric patient with refractory acute lymphoblastic leukemia who developed life-threatening massive gross hematuria. Along with platelet infusion every other day due to suppressed hematopoiesis, his gross hematuria and clot retention in the bladder were successfully treated with choreito, a formula from Japanese traditional medicine (Kampo medicine). He survived free from hematuria for more than four months. Choreito was well tolerated, and no adverse effects were observed throughout the course.

Recurrent MYB rearrangement in blastic plasmacytoid dendritic cell neoplasm

Lymphoproliferative Disorders Team, Centre de Recherche des Cordeliers, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France; Service d’Hématologie Biologique, GH Pitié-Salpêtrière, Paris, France; Service de Biostatistique et Informatique Médicale, Hôpital Saint Louis, Paris, France.; Département de génétique, GH Pitié-Salpêtrière, Paris, France; INSERM U1170, Institut Gustave Roussy, Villejuif, France; Département d’Hématologie, Hôpital Becquerel, Rouen, France; Pôle d’Hématologie, Hôpital Brabois, Vandoeuvre-les-Nancy, France; Service d’Hématologie Clinique, Hôpital d’Argenteuil, Argenteuil, France and Karyopharm Therapeutics, Newton, MA, USA E-mail: santos.susin@crc.jussieu.fr or florence.nguyen-khac@psl.aphp.fr These authors contributed equally to this work. Senior coauthorship.

Successful treatment of pulmonary hypertension with beraprost and sildenafil after cord blood transplantation for infantile leukemia

Pulmonary hypertension (PH) is an infrequently reported complication after hematopoietic stem cell transplantation, and its etiology and therapeutic strategies, especially in infants, remain unclear. We report a case of severe PH that developed in an infant with acute leukemia following administration of busulfan as a preconditioner for cord blood transplantation; the case was successfully treated with sildenafil and beraprost, which to our knowledge is the first reported successful use of this regimen in PH following transplantation for infantile leukemia. From a review of all previous reports, use of busulfan in infants may raise the risk of developing PH, and unlike definitive pulmonary veno-occlusive disease, PH in this subgroup may be reversible by early detection and treatment.

Clinical utility of next-generation sequencing-based minimal residual disease in paediatric B-cell acute lymphoblastic leukaemia

We assessed the clinical utility of next‐generation sequencing (NGS)‐based monitoring of minimal residual disease (MRD) in a uniformly treated cohort of 79 patients with paediatric B‐cell acute lymphoblastic leukaemia. Bone marrow samples were collected at the time of diagnosis, days 33 and 80, pre‐ (4–5 months) and post‐ (24 months) maintenance therapy time points, and at relapse. We identified leukaemia‐specific CDR3 sequences in 72 of 79 patients (91%) and detected MRD in 59 of 232 samples. Although MRD was detected in 28 of 55 samples (51%) on day 33, the frequencies of MRD detection decreased to 25% (16/65) at day 80, 19% (11/58) at 4–5 months and 7·4% (4/54) at 24 months. In a univariate analysis, positive MRD results on day 80 [relative risk (RR) 95% confidence interval (CI) = 7·438 (2·561–21·6), P < 0·001], at 4–5 months [RR (95% CI) = 10·24 (3·374–31·06), P < 0·001], and at 24 months [RR (95% CI) = 19·26 (4·974–74·59), P < 0·001] exhibited statistically significant associations with inferior leukaemia‐free survival; this was confirmed using a Cox proportional hazard model. Our study suggests the promising potential of NGS‐MRD for patients with B‐cell ALL.

Aldehyde dehydrogenase-2 polymorphism contributes to the progression of bone marrow failure in children with idiopathic aplastic anaemia

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