Sequential use of second-generation tyrosine kinase inhibitors following imatinib therapy in pediatric chronic myeloid leukemia: A report from the Japanese Pediatric Leukemia/Lymphoma Study Group.

BACKGROUND: The details of the sequential use of imatinib for first-line treatment followed by second-generation tyrosine kinase inhibitors (2G-TKIs) for pediatric chronic myeloid leukemia (CML) are still unknown. This study analyzed clinical responses and adverse effects of the use of 2G-TKIs following imatinib in pediatric chronic phase (CP)-CML. PROCEDURES: The Japanese Pediatric Leukemia/Lymphoma Study Group conducted a retrospective study of patients with newly diagnosed CML from 1996 to 2011. A total of 152 cases that received imatinib as first-line therapy were analyzed. RESULTS: Excluding 46 cases treated with hematopoietic stem cell transplantation before nilotinib and dasatinib became available, 31 of 106 patients changed to 2G-TKIs. The primary reason for changing from imatinib was poor response, followed by intolerance, with the main reason for the latter being musculoskeletal events. Switches from imatinib to 2G-TKIs with intolerance occurred significantly earlier than switches with poor response. Sixteen and 15 patients were treated with nilotinib and dasatinib, respectively, following imatinib therapy. After switching to 2G-TKIs, the response status improved in 63% of evaluable patients. The adverse effect profiles of nilotinib and dasatinib tended to be different, with hyperbilirubinemia observed in 33% of nilotinib-treated patients, but in none of the cases with dasatinib. CONCLUSION: This retrospective study represents the first series of children and adolescents in whom sequential use of imatinib followed by 2G-TKIs was reported. These data provide useful insights into the selection of 2G-TKIs as first-line treatment for children and adolescents with CP-CML.

Flow cytometric analysis as an additional predictive tool of treatment response in children with chronic-phase chronic myeloid leukemia treated with imatinib.

Bone marrow samples of newly diagnosed children with chronic-phase chronic myeloid leukemia (CML) were obtained at diagnosis and after imatinib initiation and stained with anti-human CD34, CD38, CD123, CD45RA, cMpl, and lineage antibodies. Flow cytometric analysis revealed that granulocyte macrophage progenitor predominance in CML progenitors at diagnosis and elevated cMpl expression in bone marrow progenitors at 3 months may predict poor outcome in children with chronic-phase CML treated with imatinib. We recommend flow cytometric analysis of bone marrow in the early phase of treatment, as it is a convenient tool that may predict treatment response and guide CML management.

Leukostasis in Children and Adolescents with Chronic Myeloid Leukemia: Japanese Pediatric Leukemia/Lymphoma Study Group.

BACKGROUND: The details of leukostasis in children and adolescents with chronic myeloid leukemia (CML) are unknown. This study determined the characteristics of leukostasis in children and adolescents with CML. PROCEDURE: A total of 256 cases from a retrospective study of patients with CML conducted by the Japanese Pediatric Leukemia/Lymphoma Study Group from 1996 to 2011 were analyzed, and of these, 238 cases were evaluated in this study. RESULTS: Leukostasis was diagnosed in 23 patients (9.7%). The median leukocyte count and spleen size below the left costal margin in cases with leukostasis were significantly higher and larger when compared to those in cases without leukostasis (458.5 × 10(9) /l vs. 151.8 × 10(9) /l (P < 0.01), and 13 vs. 5 cm (P < 0.01), respectively). Leukostasis occurred with ocular symptoms in 14 cases, priapism in four cases, and dyspnea, syncope, headache, knee pain, difficulty hearing, and aseptic necrosis of the femoral head in one case each. One case had two leukostasis symptoms simultaneously. Three cases were diagnosed before imatinib became available. Five cases received special treatment, and in the remaining 15 cases, all of these symptoms resolved after treatment with imatinib. CONCLUSIONS: This retrospective study represents the largest series of children and adolescents in which leukostasis of CML has been reported. Our data provide useful insight into the characteristics of leukostasis in recent cases of children and adolescents with CML.

Prenatal diagnosis of right aortic arch with mirror-image branching without associated anomalies.

A pregnant woman at 32 weeks of gestation was referred because of untypical visualization of a three-vessel tracheal view. Detailed ultrasound examination demonstrated an abnormal position of descending aorta, positioned at the right-front side of the spine at the level of four-chamber view. The descending aorta was connected with left pulmonary artery through ductus arteriosus, which configured a vascular ring. Right aortic arch with mirror-image branching without any associated anomaly was suspected prenatally. Amniocentesis showed no chromosomal abnormality. A male, 2440-g infant was delivered vaginally at 37 weeks and 4 days of gestation. Echocardiography confirmed no associated congenital heart defect. Three-dimensional reconstruction using 64-slice spiral computed tomography angiography at 2-months old confirmed the diagnosis of right aortic arch with mirror-image branching. The infant is now 1 year old and well developed without any symptoms.

The association between the social adaptive skills of school-aged children with congenital heart disease and mothers' decision factors for providing disease explanations in Japan: a cross-sectional study.

PURPOSE: This study aimed to clarify the factors related to mothers' decisions to provide disease explanations to their children, investigate the associations between those factors and social adaptive skills, and examine support relative to children's growth and development. METHODS: Data were collected from anonymous, self-administered questionnaires answered by 71 mothers of outpatient school-aged children with congenital heart disease. The questionnaire items included characteristics of mothers and children, decision factors for providing disease explanations, and children's social adaptive skills (Asahide-Shiki social adaptive skills test). Factor analysis was performed on the decision factors, and multiple regression analysis was performed to examine the association between the identified factors and each social adaptive skill. RESULTS: The decision factors for providing disease explanations were the mother's explanation ability, the receptive capability of the child, and the child's interest and literacy regarding the explanation. Multiple regression analysis showed that language and social life skills were significantly associated with the child's receptive capability, and language and daily life skills were significantly associated with the child's interest and literacy regarding the explanation. CONCLUSION: Improving children's language, social life, and daily life skills may enhance their receptive capability and literacy regarding explanations of their disease.

Distinct impact of imatinib on growth at prepubertal and pubertal ages of children with chronic myeloid leukemia.

OBJECTIVE: To determine the extent of growth impairment resulting from imatinib treatment in children with chronic myeloid leukemia (CML). STUDY DESIGN: Clinical records of 48 chronic-phase CML children administered imatinib as the first-line therapy between 2001 and 2006 were analyzed retrospectively. Cumulative change in height was assessed using the height height-SDS and converted height data from age- and sex-adjusted Japanese norms. RESULTS: A decrease in height-SDS was observed in 72.9% of children, with a median maximum reduction in height-SDS of 0.61 during imatinib treatment. Median follow-up time was 34 months (range, 10-88 months). Growth impairment was seen predominantly in children who started imatinib at a prepubertal age compared with those who started at pubertal age. Growth velocity tended to recuperate in prepubertal children with growth impairment, as they reached pubertal age, suggesting that imatinib had little impact on growth during puberty. CONCLUSIONS: Growth impairment was a major adverse effect of long-term imatinib treatment in children with CML. We report the distinct inhibitory effect of imatinib on growth in prepubertal and pubertal children with CML. We should be aware of growth deceleration in children, especially in young children given imatinib before puberty and subjected to prolonged exposure.

Outcome of 125 children with chronic myelogenous leukemia who received transplants from unrelated donors: the Japan Marrow Donor Program.

Because of a small number of patients, only a few studies have addressed the outcome of bone marrow transplantation (BMT) in children with Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML), who receive graft from a volunteer-unrelated donor (VUD), especially after practical application of imatinib mesylate. The outcomes of BMT from a VUD in 125 children with Ph+ CML were retrospectively reviewed. Patients were identified through the Japan Marrow Donor Program as having undergone BMT between 1993 and 2005 and were aged 1-19 years at the time of transplant (median age, 14 years). The probabilities of 5-year overall survival (OS) and leukemia-free survival (LFS) were 59.3% and 55.5%, respectively. Multivariate analysis identified the following unfavorable survival factors: infused total nucleated cell dose<314 x 10(6) /kg (relative risk [RR]=2.43; 95% confidence interval [CI]=1.33-4.44; P=.004), advanced phase (RR=2.43; 95% CI=1.37-4.31; P=.004), and no major cytogenetic response (MCyR) at the time of BMT (RR=6.55; 95% CI=1.98-21.6; P=.002). Of the 17 patients treated with imatinib, 15 (88%) achieved MCyR at the time of BMT, and this group had an excellent 5-year OS of 81.9%. Disease phase, infused total nucleated cell dose, and cytogenetic response were independent risk factors for survival of unrelated BMT. These findings provide important information for assessing the indications for and improving outcome in unrelated BMT for the treatment of pediatric CML.

Randomized trial to compare LSA2L2-type maintenance therapy to daily 6-mercaptopurine and weekly methotrexate with vincristine and dexamethasone pulse for children with acute lymphoblastic leukemia.

BACKGROUND: A total of 201 pediatric cases of acute lymphoblastic leukemia were treated with the ALL-96 protocol by the Kyushu-Yamaguchi Children's Cancer Study Group. PROCEDURE: Risk stratification was based on white cell counts, immunophenotype, the presence of central nervous system disease at diagnosis, organomegaly, and early treatment response (day 14 bone marrow status). All of the patients were classified into standard-risk (SR) or high-risk (HR) groups and were randomly assigned to receive maintenance therapy with either LSA2L2-type or 6-mercaptopurine (6-MP)/methotrexate (MTX) with vincristine (VCR) and dexamethasone (DEX) pulse in both risk groups. RESULTS: The 7-year event-free survival (EFS) and overall survival (OS) rates in the entire study population were 72.1% (95% CI: 68.0-76.2%) and 84.8% (95% CI: 79.7-89.9%), respectively, and the EFS of the SR patients (85.3% [95% CI: 78.2-92.4%]) was significantly better than HR patients (62.4% [95% CI: 52.2-72.6%]) (P = 0.0007). CONCLUSIONS: There were no differences in the EFS between the different maintenance therapies in each risk group; however, grade IV liver toxicity occurred more often in the patients receiving 6-MP/MTX with VCR and DEX therapy than in patients receiving LSA2L2.

Clinical impact of HLA-DR15, a minor population of paroxysmal nocturnal haemoglobinuria-type cells, and an aplastic anaemia-associated autoantibody in children with acquired aplastic anaemia.

Aplastic anaemia (AA) is defined as a pancytopenia caused by bone marrow failure, and its pathogenesis is thought to involve autoimmune processes. Several predictive markers of the response to immunosuppressive therapy (IST) have been proposed, which appear to reflect the immune pathophysiology. We prospectively investigated the presence of human leucocyte antigen (HLA)-DR15, a minor population of paroxysmal nocturnal haemoglobinuria (PNH)-type cells, and antibodies to the recently identified autoantigen postmeiotic segregation increased 1 (PMS1) in 103 children with AA enrolled in a multicentre study. In contrast to adults, children with AA did not show an increased frequency of HLA-DR15. In addition, a sensitive flow cytometric assay revealed that children with AA have a much lower prevalence of PNH-type cells (21.4%) than reported for adults with this disease. An immunoblotting assay detected anti-PMS1 antibody in 15 of 103 (14.6%) of the children. Finally, the response rate to IST was not significantly different between patients with and without DR15 (45.5% vs. 54.0%), PNH-type cells (68.2% vs. 53.1%) or anti-PMS1 antibody (40.0% vs. 59.1%). The current study did not confirm a correlation between these markers and the response to IST, suggesting that there is a difference in the pathophysiologies of adult and paediatric AA.

Clinical and genetic analyses of presumed Shwachman-Diamond syndrome in Japan.

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, and skeletal abnormalities. SBDS was identified as a causative gene for SDS in 2003, and genetic analyses of SDS have been performed. We performed genetic analysis of 13 Japanese patients with presumed SDS and found that 10 of them had SBDS mutations. Most patients had recurrent mutations (181-184TA-->CT and 258+2T-->C); however, 2 patients had unique mutations (259-1G-->A and 428C-->G). Although genetic analysis is useful for definitive diagnosis and for genetic counseling of SDS patients and families, SDS appears to be a genetically heterogeneous disorder. In addition, presumed SDS patients without SBDS mutations may be included in other disorders.

Effective VCR/DEX pulse maintenance therapy in the KYCCSG ALL-02 protocol for pediatric acute lymphoblastic leukemia.

In a previous study of childhood acute lymphoblastic leukemia (ALL) by the Kyushu-Yamaguchi Children's Cancer Study Group, ALL-96, we achieved a 72.1 % 5-year event-free survival (EFS) and an 84.8 % 5-year overall survival (OS). In a subsequent study, ALL-02, we adopted a vincristine dexamethasone (VCR/DEX) pulse regimen as maintenance therapy in the context of the ALL-96 study using the same risk classification and treatment schedule. A total of 156 pediatric cases of ALL were treated with ALL-02. All of the patients were classified as standard-risk or high-risk. Risk stratification was based on white cell counts, immunophenotype, the presence of central nervous system (CNS) disease at diagnosis, organomegaly, and early treatment response (day 14 bone marrow status). The 7-year EFS and OS rates were 77.7 % (95 % CI 70.6-84.8 %) and 89.5 % (95 % CI 84.6-94.4 %), respectively. CNS 3 status [hazard ratio (HR) = 5.0, p = 0.009] and high white blood cell count at diagnosis (HR = 2.6, p = 0.047) were risk factors for poor EFS in multivariate analysis. Our strategies to categorize patients into two risk groups, and to treat with a VCR/DEX pulse were feasible and reasonably effective treatments for pediatric ALL.

Identification of mutations through dominant screening for obesity using C57BL/6 substrains.

The discovery of leptin substantiated the usefulness of a forward genetic approach in elucidating the molecular network regulating energy metabolism. However, no successful dominant screening for obesity has been reported, which may be due to the influence of quantitative trait loci between the screening and counter strains and the low fertility of obese mice. Here, we performed a dominant screening for obesity using C57BL/6 substrains, C57BL/6J and C57BL/6N, with the routine use of in vitro fertilization. The screening of more than 5000 mutagenized mice established two obese pedigrees in which single nucleotide substitutions in Mc4r and Sim1 genes were identified through whole-exome sequencing. The mutation in the Mc4r gene produces a premature stop codon, and the mutant SIM1 protein lacks transcriptional activity, showing that the haploinsufficiency of SIM1 and MC4R results in obesity. We further examined the hypothalamic neuropeptide expressions in the mutant pedigrees and mice with diet-induced obesity, which showed that each obesity mouse model has distinct neuropeptide expression profiles. This forward genetic screening scheme is useful and applicable to any research field in which mouse models work.

Preferential incorporation of shorter and less unsaturated acyl phospholipids into high density lipoprotein-like particles in the ABCA1- and ABCA7-mediated biogenesis with apoA-I.

Molecular species of phosphatidylcholine (PC) and sphingomyelin (SPM) were globally analyzed for lipidomics in the nascent high-density lipoprotein (HDL)-like particles generated with human apolipoprotein A-I (apoA-I) form HEK293 cells where either human ATP binding cassette transporter (ABC) A1 or ABCA7 was transfected and overexpressed. SPM/PC ratio was higher in the ABCA1-mediated HDL than ABCA7-mediated HDL likely being related to their cholesterol content, while it was less than the ratio in the cell membrane in either case. Molecular species composition of hydrocarbon chain moiety in each phospholipid in the HDL largely reflected that in the cells the lipoprotein originated in, without remarkable difference between ABCA1 and ABCA7. Further analysis, however, revealed apparent preference for the molecules with shorter hydrocarbon chain length for both PC and SPM in their relative incorporation into HDL by ABCA1 and ABCA7. Likewise, it was in favor for less-unsaturated hydrocarbon chains of PC while this preference was not apparent for SPM. The results are consistent with the view that assembly of HDL particles with extracellular apoA-I is primarily with the cellular phospholipid molecules being regulated in part by their physicochemical nature.

Clinical characteristics and genetic analysis of childhood acute lymphoblastic leukemia with hemophagocytic lymphohistiocytosis: a Japanese retrospective study by the Kyushu-Yamaguchi Children's Cancer Study Group.

This present study sought to analyze acute lymphoblastic leukemia (ALL) patients with hemophagocytic lymphohistiocytosis (HLH) registered in Kyushu-Yamaguchi Children's Cancer Study Group studies conducted between 1996 and 2007. Four of 357 patients, including two of 318 patients with B cell precursor acute lymphoblastic leukemia (BCP-ALL) and two of 39 of those with T cell acute lymphoblastic leukemia (T-ALL), were identified. HLH was observed more frequently in the T-ALL patients than in the BCP-ALL patients (P = 0.061). The mean age of 13.0 years at the diagnosis of leukemia in the HLH + ALL group was significantly higher than the 6.05 years observed in the remaining ALL groups (P = 0.001). A female predisposition was noted, as all four patients were female (P = 0.043). In two of four patients, the leukemic cells exhibited deletions on the long arm of chromosome 6 (P = 0.003). Three patients suffered from HLH during maintenance therapy. Parvovirus B19 infection and cytomegalovirus reactivation were identified as causes of HLH in one and two patients, respectively. All four patients are currently in complete remission, although one developed relapse of leukemia after receiving maintenance therapy. Based on the genetic analyses, non-synonymous single nucleotide polymorphisms (SNPs) in UNC13D, syntaxin 11, and STXBP2 were identified in all patients. Clinicians should therefore be aware of the risk of HLH during maintenance therapy, especially in older T-ALL patients with SNPs in familial HLH causative genes.

Acute lymphoblastic leukemia and Down syndrome: the collaborative study of the Tokyo Children's Cancer Study Group and the Kyushu Yamaguchi Children's Cancer Study Group.

The Tokyo Children's Cancer Study Group (TCCSG) and the Kyushu Yamaguchi Children's Cancer Study Group (KYCCSG) performed a collaborative analysis of data on children with Down syndrome and acute lymphoblastic leukemia (DS-ALL). Among the 1,139 patients who were enrolled in the TCCSG L99-15, L99-1502, or the KYCCSG ALL 96 study, 13 patients with newly diagnosed ALL had DS. In the DS patients, a significantly higher proportion of patients developed ALL at age 5 years or older compared with the non-DS ALL patients (P < 0.001). The 5-year relapse-free or overall survival of DS-ALL patients was 50.0 or 61.5%, respectively. Relapse accounted for all causes of death. In the TCCSG L99-15 cohort, the overall survival of DS-ALL patients was 42.9%, which was significantly worse compared with 87.9% in the non-DS population (P < 0.001). The survival of patients who received reduced-dose chemotherapy was significantly worse than those who received full-dose chemotherapy (P < 0.001). However, a higher dose of methotrexate was not associated with a better outcome. Results of our preliminary study suggest that the survival of DS-ALL patients could be improved by treatment without dose reduction if possible, although the appropriate dose of methotrexate for DS-ALL needs to be determined.

Nuclear factor-kappaB activation in peripheral blood mononuclear cells in children with sepsis.

OBJECTIVE: To determine the activation of nuclear factor-[kappa]B in peripheral blood CD14+ monocyte/macrophages and CD3+, CD4+, and CD8+ T cells in children with sepsis. DESIGN: Observational study. SETTING: University hospital. PATIENTS: Twenty-six children with sepsis (nine females and 17 males, aged between 10 days and 15 yrs; median, 4.3 yrs) on admission to our hospital between August 1999 and November 2005. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The percentages of peripheral blood CD14+ monocyte/macrophages and CD3+, CD4+, and CD8+ T cells exhibiting nuclear factor-[kappa]B activity were determined by flow cytometry. In addition, relationships among the degree to which nuclear factor-[kappa]B was activated, serum levels of cytokines (interferon-[gamma], tumor necrosis factor-[alpha], interleukin-2, interleukin-4, interleukin-6, and interleukin-10), and clinical variables were analyzed. The percentage of cells exhibiting nuclear factor-[kappa]B activity was increased among CD14+, CD3+, CD4+, and CD8+ cells in the sepsis group and was significantly higher among CD14+, CD3+, and CD4+ cells of the patients with severe sepsis (n = 9) than those of patients with nonsevere sepsis (n = 17). The percentage of cells exhibiting nuclear factor-[kappa]B activity was significantly higher among CD14+ cells than CD3+ cells in the patients with severe sepsis. In addition, this percentage was significantly higher among CD14+ cells than CD3+, CD4+, and CD8+ cells in septic patients who had positive blood cultures (n = 16). Serum interleukin-6 levels were correlated with the percentages of CD14+, CD3+, CD4+, and CD8+ cells exhibiting nuclear factor-[kappa]B activity, and serum IL-10 levels were correlated with the percentages of CD14+, CD3+, and CD4+ cells exhibiting nuclear factor-[kappa]B activity. CONCLUSIONS: Nuclear factor-[kappa]B in peripheral blood mononuclear cells was activated in children with sepsis and was related the severity of sepsis.

Infants with acute lymphoblastic leukemia and a germline MLL gene are highly curable with use of chemotherapy alone: results from the Japan Infant Leukemia Study Group.

Although infants with acute lymphoblastic leukemia (ALL) and a germline MLL gene have a better prognosis than comparable infants with a rearranged MLL gene, their optimal therapy is controversial. In 2 consecutive studies, conducted between 1996 and 2002, we treated 22 cases of infant ALL with germline MLL using chemotherapy alone. The 5-year event-free survival rate was 95.5% with a 95% confidence interval of 86.9 to 100%. All 21 infants with precursor B-cell ALL have been in first complete remission for 3.5 to 8.8 years. Most treatment-related toxicities were predictable and well tolerated, and neither secondary malignancies nor physical growth impairments have been observed. These results indicate that chemotherapy of the type described here is both safe and highly effective against infant precursor B-cell ALL with MLL in the germline configuration.