[Show abstract][Hide abstract] ABSTRACT: We report the outcomes of 30 patients with juvenile myelomonocytic leukemia (JMML) who received unmanipulated hematopoietic stem cell transplantation (HSCT) with oral or intravenous busulfan, fludarabine, and melphalan between 2001 and 2011. Mutations in PTPN11 were detected in 15 patients. Six patients received human leukocyte antigen (HLA)-matched HSCT from related donors, and 24 patients received HSCT from alternative donors, including 13 HLA-mismatched donors. Primary engraftment failed in five patients, all of whom had received allografts from HLA-mismatched donors. HLA-mismatched HSCT resulted in poorer event-free survival than HLA-matched HSCT (28.8 vs. 70.6 %). Three patients died of transplantation-related causes, and eight patients experienced hematological relapse (including five patients who died due to disease progression). Eight patients received a second HSCT, and four of these patients have survived. The 5-year estimated overall survival for all patients was 72.4: 88.9 % for the patients without a mutation in PTPN11 (n = 10) and 58.3 % for the patients with a mutation in PTPN11 (n = 15) (P = 0.092). The conditioning regimen reported in the present study achieved hematological and clinical remission in >50 % of patients with JMML who received HSCT from alternative donors, and may also be effective for JMML patients with PTPN11 mutation.
International Journal of Hematology 12/2014; 101(2). DOI:10.1007/s12185-014-1715-7 · 1.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Severe combined immunodeficiency (SCID) is a syndrome characterized by profound T-cell deficiency. BCG vaccine is contraindicated in patients with SCID. Because most countries encourage BCG vaccination at birth, a high percentage of patients with SCID are vaccinated before their immune defect is detected.
We sought to describe the complications and risks associated with BCG vaccination in patients with SCID.
An extensive standardized questionnaire evaluating complications, therapeutics, and outcomes regarding BCG vaccination in patients given a diagnosis of SCID was widely distributed. Summary statistics and association analysis was performed.
Data on 349 BCG-vaccinated patients with SCID from 28 centers in 17 countries were analyzed. Fifty-one percent of the patients had BCG-associated complications, 34% disseminated and 17% localized (a 33,000- and 400-fold increase, respectively, over the general population). Patients receiving early vaccination (≤1 month) showed an increased prevalence of complications (P = .006) and death caused by BCG-associated complications (P < .0001). The odds of experiencing complications among patients with T-cell numbers of 250/μL or less at diagnosis was 2.1 times higher (95% CI, 1.4-3.4 times higher; P = .001) than among those with T-cell numbers of greater than 250/μL. BCG-associated complications were reported in 2 of 78 patients who received antimycobacterial therapy while asymptomatic, and no deaths caused by BCG-associated complications occurred in this group. In contrast, 46 BCG-associated deaths were reported among 160 patients treated with antimycobacterial therapy for a symptomatic BCG infection (P < .0001).
BCG vaccine has a very high rate of complications in patients with SCID, which increase morbidity and mortality rates. Until safer and more efficient antituberculosis vaccines become available, delay in BCG vaccination should be considered to protect highly vulnerable populations from preventable complications.
The Journal of allergy and clinical immunology 04/2014; 133(4):1134-41. DOI:10.1016/j.jaci.2014.02.028 · 11.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Patients with severe aplastic anemia (SAA) and an absolute neutrophil count (ANC) of 0 typically have fatal outcomes. We defined fulminant AA (FAA) as ANC = 0 for at least 2 weeks prior to and after immunosuppressive therapy (IST). We analyzed the outcomes of 35 children with FAA among 288 children who enrolled in a prospective study for AA (AA-97 study). AA was classified as FAA (n = 35), very SAA (vSAA; n = 129), or SAA (n = 124). All of the children received the IST with horse anti-thymocyte globulin (ATG) and cyclosporine (CsA). A significantly lower response rate at 6 months was seen in children with FAA when compared to those with vSAA or SAA (40.0, 63.6, and 63.7 %, respectively; p = 0.027). Of 20 nonresponder patients in the FAA group, 11 were rescued by alternative donor transplantation, and 5 patients showed a late response after 6 months. Consequently, no significant difference was noted in overall survival when comparing the FAA, vSAA, and SAA groups (88.5, 95.8, and 96.8 %). These findings indicate that IST with ATG and CsA is justified as a first-line treatment for children with FAA who lack a human leukocyte antigen-matched sibling donor.
Annals of Hematology 12/2013; 93(5). DOI:10.1007/s00277-013-1984-x · 2.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Acquired somatic mutations of JAK2 have been reported to play a pivotal role in the pathogenesis of BCR-ABL1-negative myeloproliferative neoplasm (MPN). However, the molecular characteristics of childhood MPN remain to be elucidated.
We investigated a group of pediatric patients diagnosed either with essential thrombocythemia (ET; N = 9) or polycythemia vera (PV; N = 4) according to WHO criteria (median age = 10 years; range 1.5-15 years) in whom direct sequencing was performed for the existence of genetic alterations in JAK2, MPL, TET2, ASXL1, CBL, IDH1, and IDH2. More sensitive allele specific polymerase chain reaction was used for JAK2(V617F) genotyping.
We found three patients harbor JAK2(V617F) mutation (2/9 ET and 1/4 PV). Bone marrow examination showed small and large megakaryocytes with dysplastic features in JAK2(V617F)-positive ET patients compared to those without JAK2(V617F). We identified a previously unrecognized missense mutation at codon 1230 in exon 12 of ASXL1 gene in ET and PV patients (1/9 ET and 1/4 PV). Otherwise, no genetic alterations could be detected in JAK2 exon 12, MPL, TET2, CBL, IDH1, and IDH2 in all ET and PV patients.
Although JAK2 mutations in childhood ET and PV are not as frequent as reported in adult patients, JAK2 is the most frequently mutated gene in childhood MPN known so far. Owing to the presence of childhood MPN without any genetic alterations in JAK2, MPL, TET2, ASXL1, CBL, IDH1, and IDH2, new biological markers have to be found.
[Show abstract][Hide abstract] ABSTRACT: We report the outcome of 16 children with refractory anaemia with excess of blasts (RAEB; n = 4) and RAEB in transformation (RAEB-T; n = 12) following induction therapy with etoposide, cytarabine and mitoxantrone (ECM) prior to haematopoietic stem cell transplantation (HSCT). The median observation period was 77 months (range 5-123). Complete remission rate was 81% following induction; no toxic deaths occurred. Eight-year event-free survival and overall survival was 50% and 56%, respectively. None of the three patients with a complex karyotype survived, suggesting karyotype is a crucial prognostic factor for survival. This study indicates the safety and high remission rate of ECM and high survival rates after HSCT for paediatric RAEB and RAEB-T.
British Journal of Haematology 06/2012; 158(5):657-61. DOI:10.1111/j.1365-2141.2012.09210.x · 4.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although hematopoietic stem cell transplantation (HSCT) is offered as a curative therapy for pediatric myelodysplastic syndrome (MDS), it may cause severe complications and mortality. Several reports have shown the efficacy of immunosuppressive therapy (IST) in adult patients with refractory anemia (RA), but its safety and efficacy remains to be fully elucidated in childhood RA.
Eleven children diagnosed with RA and enrolled on a prospective multicenter trial conducted by the Japanese Childhood MDS Study Group were eligible for analysis. If patients showed transfusion dependent or suffered from infection due to neutropenia, they received IST consisting of antithymocyte globulin (ATG), cyclosporine (CyA), and methylprednisolone (mPSL).
Eight children received IST, 2 received only supportive therapy, and one underwent HSCT without IST. Five (63%) of eight children who received IST showed hematological response. Of note, one patient showed the disappearance of monosomy 7 after IST. Responders were significantly younger than non-responders (29 months vs. 140 months; P = 0.03). No severe adverse events related to IST were reported in this study. Of 6 children with chromosomal abnormalities who received IST, four showed hematological response. The probability of failure-free and overall survival at 5 years was 63 +/- 17% and 90 +/- 9% respectively.
IST is likely to be a safe and effective modality for childhood RA.
[Show abstract][Hide abstract] ABSTRACT: To assess the feasibility of T-cell receptor excision circles (TRECs) quantification for neonatal mass screening of severe combined immunodeficiency (SCID).
Real-time PCR based quantification of TRECs for 471 healthy control patients and 18 patients with SCID with various genetic abnormalities (IL2RG, JAK3, ADA, LIG4, RAG1) were performed, including patients with maternal T-cell engraftment (n = 4) and leaky T cells (n = 3).
TRECs were detectable in all normal neonatal Guthrie cards (n = 326) at the levels of 10(4) to 10(5) copies/microg DNA. In contrast, TRECs were extremely low in all neonatal Guthrie cards (n = 15) and peripheral blood (n = 14) from patients with SCID, including those with maternal T-cell engraftment or leaky T cells with hypomorphic RAG1 mutations or LIG4 deficiency. There were no false-positive or negative results in this study.
TRECs quantification can be used as a neonatal mass screening for patients with SCID.
The Journal of pediatrics 08/2009; 155(6):829-33. DOI:10.1016/j.jpeds.2009.05.026 · 3.79 Impact Factor