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In Western countries, gene alterations involving the CRLF2-JAK signaling pathway are identified in approximately 50-60% of patients with Down syndrome-associated acute lymphoblastic leukemia (DS-ALL), and this pathway is considered a potential therapeutic target. The frequency of BTG1 deletions in DS-ALL is controversial. IKZF1 deletions, found in 20-30% of DS-ALL patients, are associated with a poor outcome and EBF1 deletions are very rare (∼2%). We analyzed 38 patients to determine the frequencies and clinical implications of CRLF2-JAK pathway genetic alterations and recurrent gene deletions in Japanese DS-ALL patients. We confirmed a high incidence of P2RY8-CRLF2 (29%) and JAK2 mutations (16%), though the frequency of P2RY8-CRLF2 was slightly lower than that in Western countries (∼50%). BTG1 deletions were common in our cohort (25%). IKZF1 deletions were detected in 25% of patients and associated with shorter overall survival (OS). EBF1 deletions were found at an unexpectedly high frequency (16%), and at a significantly higher level in P2RY8-CRLF2-positive patients than in P2RY8-CRLF2-negative patients (44% vs. 4%, P=0.015). Deletions of CDKN2A/B and PAX5 were common in P2RY8-CRLF2-negative patients (48 and 39%, respectively) but not in P2RY8-CRLF2-positive patients (11% each). Associations between these genetic alterations and clinical characteristics were not observed except for inferior OS in patients with IKZF1 deletions. These results suggest that differences exist between the genetic profiles of DS-ALL patients in Japan and in Western countries, and that P2RY8-CRLF2 and EBF1 deletions may cooperate in leukemogenesis in a subset of Japanese DS-ALL patients.

HLA-haploidentical 2 or 3-loci mismatched families are alternative donors for high-risk patients without HLA-matched donors. We retrospectively reviewed our case series of HLA-halpoidentical hematopoietic stem cell transplantations (haplo-HSCTs). Between Jul 2005 and Dec 2012, 25 patients (median age, 8 y; 13 ALL, 8 AML, 4 others) received haplo-HSCTs because of a worsening prognosis (i.e. induction failure, non-CR, or relapse after prior HSCT). Disease status was CR in 8 and non-CR in 17 patients. The 17 patients received myeloablative conditioning, while the 8 were given reduced-intensity conditioning because of their conditions (e.g. early relapse after prior HSCT). ATG was not administered in all but 3 patients. Tacrolimus and sMTX were used for prophylaxis GVHD and steroids were immediately given to prevent the onset of aGVHD. The 3-year OS and EFS were 35.6±10.0% and 31.3±10.1%, respectively (median follow-up, 49 mo); 14 patients died of their primary disease. Grade 3-4 aGVHD occurred in 7 patients, 2 of whom died of grade 4 aGVHD. Eleven patients had extensive cGVHD. While 4 of the 8 CR patients remained in CR, only 4 of the 17 non-CR patients achieved long-term CR (survival time, 6-89 mo). Haplo-HSCT was tolerable with strict control of infections and GVHD. However, further strategies for non-CR patients appear to be required.

X-linked lymphoproliferative syndrome (XLP) is a rare primary immunodeficiency characterized by increased vulnerability to Epstein-Barr virus infection. XLP type 1 is caused by mutations in SH2D1A, whereas X-linked inhibitor of apoptosis (XIAP) encoded by XIAP/BIRC4 is mutated in XLP type 2. In XIAP deficiency, hemophagocytic lymphohistiocytosis (HLH) occurs more frequently and recurrence is common. However, the underlying mechanisms remain mostly unknown. We describe the characteristics of the cytokine profiles of serum samples from 10 XIAP-deficient patients. The concentration of interleukin (IL)-18 was strikingly elevated in the patients presented with HLH, and remained high after the recovery from HLH although levels of other pro-inflammatory cytokines approached the normal range. Longitudinal examination of two patients demonstrated marked exacerbation of IL-18 levels during every occasion of HLH. These findings may suggest the association between HLH susceptibility and high serum IL-18 levels in XIAP deficiency. © 2013 Elsevier Ltd. All rights reserved.

Unrelated cord blood transplantation (CBT) has been worldwide for bone marrow reconstitution. CBT is associated with a high frequency of engraftment failure and rejection due to a small dose of graft cells. In cases of engraftment failure or rejection following unrelated CBT, retransplantation from the original donors is impossible. We report a successful transplantation with CD34p+ blood cells selected from a 2-loci HLA-mismatched mother to a child with acute monocytic leukemia after engraftment failure of the primary CBT. Selected CD34p+ blood cell transplantation is a useful approach for retransplantation in the setting of engraftment failure.

Between April 1994 and March 1997, 143 children (age range, 1-15 years) with newly diagnosed acute lymphoblastic leukemia (ALL), except for those patients with t(9;22), were treated according to protocol-94 of the Osaka Childhood Leukemia Study Group. In this trial, the intensity of chemotherapy was enforced in the consolidation and reinduction phases by introducing AML-type block therapies consisting of concentrated administration of 4 to 6 drugs during 5 or 6 days. For patients in the higher risk groups, rotational combination chemotherapy was introduced following the early phase. A total of 124 children with B-cell precursor ALL (B-pre ALL) were classified into 3 groups, the ultrahigh-risk group (UHRG) (15 patients), the high-risk group (HRG) (61 patients), or the standard-risk group (SRG) (48 patients), based on age. leukocyte count, immunophenotype, central nervous system leukemia, response to treatment, and selected chromosomal abnormalities. The complete remission rate was 93%, and the 6-year event-free survival (EFS) rate was 79%+/-4%. EFS rates for the UHRG, HRG, and SRG groups were 67%+/-12%, 80%+/-6%, and 81%+/-6%, respectively. Nineteen patients with T-cell ALL were treated with the protocol for the UHRG. Thirteen patients (68%) attained complete remission, and the 6-year EFS rate was 55%+/-12%. Thus, intensification of chemotherapy improved the EFS rate and AML-type block therapies appeared to be effective as the consolidation and reinduction therapies for B-pre ALL.

Inflammatory bowel diseases (ulcerative colitis and Crohn’s disease) are chronic long-lasting inflammatory diseases with yet unknown etiology. Recent advancement revealed that both diseases are associated with genetic predisposition and environmental factors such as luminal microorganisms and antigens. Crohn’s disease is associated with histopathologic features such as granuloma formation and longitudinal ulceration. In this article we describe the role of granuloma in the immunopathogenesis of Crohn’s disease. Granuloma of Crohn’s disease may play crucial roles as antigen-presenting cites to memory type T cells, which leads to activation and proliferation of T cells. Antigens presented at granuloma may be closely related to the disease.

In early childhood medulloblastoma, three distinct treatment strategies are currently used by different national groups to improve survival rates and to delay or avoid craniospinal radiotherapy: (1) systemic chemotherapy and high-dose chemotherapy, followed by radiotherapy at relapse; (2) systemic and intraventricular chemotherapy; (3) systemic chemotherapy and local conformal radiotherapy. A role for high-dose chemotherapy to delay or avoid craniospinal radiotherapy as a part of multimodal treatment strategies, especially in young children with metastatic or postoperative residual disease, has been recognized by different co-operative groups. Clinical and histological factors such as nodular-desmoplastic variants are considered as important prognostic factors for risk-adapted treatment recommendations. Pediatr Blood Cancer 2010;54:635–637. © 2009 Wiley-Liss, Inc.

SummaryBernard-Soulier syndrome (BSS) is an autosomal recessive bleeding disorder due to quantitative or qualitative abnormalities in the glycoprotein (GP) Ib/IX/V complex, the platelet receptor for von Willebrand factor. This complex is composed of four subunits, GPIbα, GPIbβ, GPIX and GPV. We describe here the genetic basis of the disorder in a patient with BSS. Flow cytometric analysis of the patient’s platelets showed greatly reduced GPIbα and GPIX surface expression. Immunoblot analysis disclosed absence of GPIbα, GPIbβ and GPIX in the platelets. DNA sequencing analysis revealed a novel missense mutation in the GPIbβ gene that converts Pro (CCG) to Arg (CGG) at residue 74. Homozygosity of the mutation was confirmed by allele-specific restriction analysis, chromosome 22 microsatellite analysis and quantitative Southern blotting. The mutant GPIbβ was normally transcribed. Transient transfection studies confirmed that mutant GPIbβ impairs surface expression of GPIb/IX, showing that the mutation is responsible for a BSS phenotype observed in the patient.

We report results of a retrospective chart review to evaluate factors predicting short-term outcome of patients with ulcerative colitis treated by corticosteroids. Between January 1992 and December 1997, we treated 71 patients with ulcerative colitis (44 with severe and 27 with moderately severe disease). Forty-nine patients were treated by conventional prednisolone therapy and 22 patients by steroid pulse therapy. There were no differences in clinical or endoscopic improvement between the two treatments. Clinical examination showed that 41 patients entered remission, 17 patients improved, and 13 patients did not respond. Endoscopically, 26 patients entered remission, 30 patients improved, and 15 patients did not respond. Extent of disease, type of disease (first attack, relapsing, or chronic active type), and endoscopic findings were factors useful in predicting short-term outcome of medical treatment.

患者は51歳の女性で, 主訴は突然の腹痛と水様便. 小腸造影で回腸末端に全周性の狭窄と縦走潰瘍を認め, Crohn病の疑いにてIVH・栄養療法を開始した. しかし, 症状は軽快せず, 蛋白漏出性胃腸症とイレウス症状が持続したため, ステロイド投与と絶食による治療を開始し, 蛋白の漏出と腹部症状は寛解したが, イレウス症状は持続した. 腹部血管造影を施行したところ上腸間膜動脈の末梢側での閉塞と側副血行路の発達を認め, 上腸間膜動脈閉塞症と診断, 側副血行の存在を確認し, 狭窄部を含めた小腸部分切除術を施行した. 組織学的には狭窄部にUL-IIIの潰瘍を認め, 潰瘍底の肉芽化が著しく壁の肥厚を認めた. 鉄染色ではヘモジデリンを貪食したマクロファージを認めた. 合併切除した腸間膜の動脈は内膜が肥厚し内腔が狭窄していた. 腹部血管造影検査にて, 上腸間膜動脈閉塞症と診断した1例を経験したので報告する.

The Polycomb group of (Pc-G) genes and trithorax group of genes are known to play a crucial role in the maintenance of the transcriptional repression state of Hox genes, probably through modification of the chro-matin configuration. The rae28/mph1 gene is a mammalian homologue of the Drosophila polyhomeotic gene, which belongs to the Pc-G genes. As reported previously, we established mice deficient in the rae28/mph1 gene and showed that these homozygous animals displayed the developmental defects compatible with a human congenital disorder, CATCH22 syndrome. In this study we analyzed the structural organization of the human counterpart of the rae28/mphlgene (RAE28IHPH1) and its processed pseudogene (ΨPH), which are located on, respectively, human chromosome 12~13 and 12q13. The HPHl gene consists of 15 exons spanning approximately 26 kb and its structural organization is well conserved between mouse and human. These genetic information of the RAE28IHPHl gene may provide an important clue for further exami...

Pneumocystis jiroveci pneumonia (PCP) is a serious complication in patients receiving chemotherapy or hematopoietic stem cell transplantation. Current recommendations for trimethoprim-sulfamethoxazole (TMP-SMZ) dosing as PCP prophylaxis in immunocompromised patients are based on either daily dosing or dosing three consecutive days per week. We report our experience of prophylaxis with TMP-SMZ twice daily on two non-consecutive days per week in 145 immunocompromised children with hematologic disorders, cancer, or metabolic disorders following chemotherapy or hematopoietic stem cell transplantation. There were no breakthrough cases of PCP. We therefore conclude our prophylaxis regimen is effective against PCP in immunocompromised children.

LAD is a rare and fatal congenital disorder in which there is a defect of the leukocyte adhesion molecule (CD18) on neutrophils. Severe LAD results in frequent and potentially fatal infections. Although allogeneic HSCT is the only curative treatment for severe LAD, strategies for HSCT remain to be established since a high engraftment failure rate and severe persistent infection are still seen. We report a four-month-old boy with LAD who was successfully treated with allogeneic HSCT from an HLA-complete matched sibling following a conditioning regimen of pharmacokinetically adjusted individual busulfan doses.

In the diagnosis of human cytomegalovirus (HCMV) infection, it is very important to distinguish symptomatic from asymptomatic infection. The nucleic acid sequence-based amplification (NASBA) technique was compared with single and nested polymerase chainreaction (PCR) methods. For NASBA detection, the beta2.7 transcript was chosen as a target because of its abundant active HCMV-specific expression. Of 20 pediatric bone marrow transplant (BMT) recipients, 8 developed HCMV-related clinical symptoms. The clinical sensitivities and specificities were 50% and 100% for single PCR, 100% and 67% for nested PCR, and 100% and 83% for NASBA, respectively. Follow-up of HCMV infections in pediatric BMT recipients showed that NASBA could both detect viral transcript prior to the onset of clinical symptoms and reflect clinical improvement due to antiviral therapy. These data suggest that NASBA should be useful for both predicting HCMV disease development and monitoring the effect of antiviral therapy.

SUMMARY 1. Phenotypical heterogeneity of macrophages infiltrating the colonic mucosa of patients with ulcerative colitis has been shown in many reports. The functional diversity of macrophages in inflamed colonic mucosa remains unclear. 2. Intestinal macrophages have been characterized by immunohistochemical staining and their ability to generate free oxygen radicals in inflamed and non-inflamed mucosa. 3. No correlation was found between RFD1 (activated dendritic cells), RFD7 (tissue macrophages) or RFD9 (epithelioid cells, giant cells in association with granuloma) positivity and either CD68 or human histocompatibility complex class II antigen (HLA-DR) positivity. The proportions of RFD7- and RFD9-positive cells were significantly increased in inflamed colonic mucosa. Nitroblue tetrazolium-reducing mononuclear cells were CD68 or RFD7 positive but they were rarely positive for HLA-DR and RFD1. 4. These results suggest that nitroblue tetrazolium-reducing macrophages are (scavenger) macrophages.

Infiltrating leucocytes are activated to generate reactive oxygen species or to produce several molecules in inflamed colonic mucosa. To clarify the phenotypical and functional properties of activating cells in colitic mucosa, 23 patients with ulcerative colitis and 13 controls were studied using a combined method for determining in situ nitroblue tetrazolium reducing activity and immunohistochemical characterization. Antibodies 25F9 (anti-macrophage), EG2 (anti-eosinophil cationic protein), MAC387 (anti-calprotectin, expressed by activated myeloid-histiocytes lineage), and MAC-1 (anti-CD11b) were used. The proportion of EG2, calprotectin, and CD11b-positive cells were significantly increased in inflamed mucosa. The proportion of EG2, calprotectin, and CD11b-positive cells significantly correlated with the histological degree of inflammation. Proportion of EG2-positive cells but not calprotectin nor CD11b-positive cells was significantly correlated with nitroblue tetrazolium reducing activity. Aggregated cells reducing nitroblue tetrazolium seen in severely inflamed mucosa were found to be EG2 positive. Most of the calprotectin-positive cells were 25F9 negative. In addition to activation of neutrophils and macrophages, eosinophil activation has been shown to be involved in inflamed colonic mucosa.

Hemophagocytic lymphohistiocytosis (HLH) is caused by the hyperactivation of T cells and macrophages. The clinical characteristics associated with this disease result from overproduction of Th1 cytokines including interferon-γ (IFN-γ), interleukin-2 (IL-2), and tumor necrosis factor-α (TNF-α). In this study, we analyzed the production of IL-12 and IL-4, which determine Th1 and Th2 response, respectively, and IL-10, which antagonizes Th1 cytokines, in 11 patients with HLH. IL-12 was detected in plasma in all patients (mean peak value, 30.0 ± 5.0 pg/mL), while IFN-γ was massively produced in nine patients (mean peak value, 79.2 ± 112.0 U/mL). IL-4 was not detected in any of the patients. Plasma IL10 levels were elevated in all patients (mean peak value, 2,698.0 ± 3,535.0 pg/mL). There was a positive correlation between the levels of IFN-γ and IL-10 (P < .01). The plasma concentrations of these cytokines were initially high, before decreasing after the acute phase. However, the decrease in IL-10 levels was slower than that of IFN-γ. Although the concentration of IL-12 was high at the acute phase, in some patients, a peak in the level was delayed until the chronic phase. Thus, in HLH, production of cytokines that promote development of Th1 cells appears to be predominant over that for Th2 cell development. Overproduction of IL-10 was also observed indicating that a mechanism suppressing hyperactivation of Th1 cells and monocytes/macrophages functions in patients with this disease.

Bone marrow (BM) stromal cells are required for normal hematopoiesis. A number of soluble factors secreted by these cells that mediate hematopoiesis have been characterized. However, the mechanism of hematopoiesis cannot be explained solely by these known factors, and the existence of other, still unknown stromal factors has been postulated. We showed that hepatocyte growth factor (HGF ) is one such cytokine produced by human BM stromal cells. BM stromal cells were shown to constitutively produce HGF and also to express the c-MET/HGF receptor. The production of HGF was enhanced by addition of heparin and phorbol ester. Dexamethasone and tumor growth factor-β (TGF-β) inhibited the production of HGF. Interleukin-1α (IL-1α) tumor necrosis factor-α (TNF-α), and N6,2′-o-dibutyryl-adenosine-3′:5′-cyclic monophosphate (dbc-AMP) showed no obvious influence on HGF production. Western blot analysis of HGF derived from BM stromal cells showed two bands at 85 and 28 kD corresponding to native and variant HGF, respectively. Addition of recombinant HGF significantly promoted the formation of burst-forming unit-erythroid (BFU-E) and colony-forming unit-granulocyte erythroid macrophage (CFU-GEM) by BM mononuclear cells in the presence of erythropoietin and granulocyte-macrophage colony-stimulating factor (GM-CSF ), but the formation of CFU-GM was not modified. However, HGF had no effects on colony formation by purified CD34+ cells. Within BM mononuclear cells, c-MET was expressed on a proportion of cells (CD34−, CD33+, CD13+, CD14+, and CD15+), but was not found on CD34+ cells. We conclude that HGF is constitutively produced by BM stromal cells and that it enhances hematopoiesis. In addition, expression of c-MET on the stromal cells suggests the presence of an autocrine mechanism, operating through HGF, among stromal cells.

To assess the clinical significance of monitoring minimal residual disease in t(8;21)(q22;q22) AML, RT-PCR assay was conducted during the clinical course of 12 patients who had undergone BMT or conventional chemotherapy. Two cases relapsed after BMT and chimeric RNA was detected soon after BMT in their bone marrow cells. The other three cases, in whom chimeric RNA was not detected after BMT, are in CR at 21 to 33 months following BMT. Similarly, four out of 7 cases who showed negative chimeric RNA after completion of chemotherapy have been in CR at 11 to 34 monthsfollowing completion of chemotherapy.The present findings appear different from other studies which reported the detection of AMLI-ETO chimeric RNA in long-term CR patients.

This study reviewed the clinical characteristics of 112 pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL) patients with TCF3-PBX1 fusion treated according to the Japan Association of Childhood Leukemia Study (JACLS) ALL02 protocol (n = 82) and Children's Cancer and Leukemia Study Group (CCLSG) ALL 2004 protocol (n = 30). The 3-year event-free survival (EFS) and overall survival (OS) rates were 85.4 ± 3.9% and 89.0 ± 3.5% in JACLS cohort, and the 5-year EFS and OS were 82.8 ± 7.0% and 86.3 ± 6.4% in CCLSG cohort, respectively, which are comparable to those reported in western countries. Conventional prognostic factors such as age at onset, initial white blood cell count, and National Cancer Institute risk have also no impact on OS in both cohorts. Surprisingly, the pattern of relapse in JACLS cohort, 9 of 82 patients, was unique: eight of nine patients relapsed during the maintenance phase and one patient had primary induction failure. However, bone marrow status and assessment of minimal residual disease on days 15 and 33 did not identify those patients. Interestingly, the two patients with IKZF1 deletion eventually relapsed in JACLS cohort, as did one patient in CCLSG cohort. International collaborative study of larger cohort is warranted to clarify the impact of the IKZF1 deletion on the poor outcome of TCF3-PBX1 positive BCP-ALL.

Genetic alterations of Ikaros family zinc finger protein 1 (IKZF1), point mutations in Janus kinase 2 (JAK2), and overexpression of cytokine receptor-like factor 2 (CRLF2) were recently reported to be associated with poor outcomes in pediatric B-cell precursor (BCP)-ALL. Herein, we conducted genetic analyses of IKZF1 deletion, point mutation of JAK2 exon 16, 17, and 21, CRLF2 expression, the presence of P2RY8-CRLF2 fusion and F232C mutation in CRLF2 in 202 pediatric BCP-ALL patients newly diagnosed and registered in Japan Childhood Leukemia Study ALL02 protocol to find out if alterations in these genes are determinants of poor outcome. All patients showed good response to initial prednisolone (PSL) treatment. Ph⁺, infantile, and Down syndrome-associated ALL were excluded. Deletion of IKZF1 occurred in 19/202 patients (9.4%) and CRLF2 overexpression occurred in 16/107 (15.0%), which are similar to previous reports. Patients with IKZF1 deletion had reduced event-free survival (EFS) and overall survival (OS) compared to those in patients without IKZF1 deletion (5-year EFS, 62.7% vs. 88.8%, 5-year OS, 71.8% vs. 90.2%). Our data also showed significantly inferior 5-year EFS (48.6% vs. 84.7%, log rank P = 0.0003) and 5-year OS (62.3% vs. 85.4%, log rank P = 0.009) in NCI-HR patients (n = 97). JAK2 mutations and P2RY8-CRLF2 fusion were rarely detected. IKZF1 deletion was identified as adverse prognostic factor even in pediatric BCP-ALL in NCI-HR showing good response to PSL.

A novel partner gene CIP29 containing a SAP domain with MLL identified in infantile myelomonocytic leukemia

BACKGROUND: The trial JACLS ALL-02 for treatment of childhood acute lymphoblastic leukemia (ALL) was designed to reduce acute and long-term toxicity in selected patient groups with favorable prognosis and to improve outcome in unfavorable-risk groups by treatment intensification. These aims were pursued through a refined stratification strategy using white blood cell count, age, immunophenotype, unfavorable genetic aberrations, and treatment response providing an excellent discrimination of risk groups. PATIENTS AND METHODS: Between April 2002 and March 2008, 1252 children with newly diagnosed de novo ALL with 1-18 years of age were enrolled to JACLS ALL-02 trial. Ph+ALL, mature B-ALL, and NK-leukemia were excluded. Patients with BCP-ALL were stratified into 3 groups: standard-risk (SR), high-risk (HR), extremely high-risk (ER), based on initial prednisolone (PSL) response and the modified National Cancer Institute(NCI) workshop criteria. Prednisolone poor response (PPR) was determined after 7 days of monotherapy with prednisone and one intrathecal dose of methotrexate. PSL good responders (PGR; < 1,000 blasts/microL) were divided into SR and HR according to the modified NCI workshop criteria by WBC 10K and age 10, and received conventional therapy. BCP-ALL with PPR (≥ 1,000 blasts/microL) or t(4;11), and acute mixed lineage leukemia/ acute unclassified leukemia were assigned to ER and received intensified post-induction therapy . Patients with T-ALL were treated by a specific protocol that was different from the protocol used for BCP-ALL. Bone marrow response was also evaluated in aspiration smears on day 15 and 33 of induction treatment, and those who had slow early bone marrow response, defined as an M3 marrow on day 15 or M2/3 marrow on day33, shifted to the higher risk and received augmented post-induction therapy. Cranial irradiation was restricted to patients with initial central nerve system involvement or T-ALL with high WBC (≥10K) at diagnosis. Alternatively, protracted TIT was given during induction, intensification and maintenance depending on the risk group (12 doses in SR/T and 15 in HR/ER). Slow early responders who had an M3 marrow on day 15 in ER/T or M2/3 marrow on day33 in any risk, underwent to stem cell transplantation (SCT). PPRs without slow early bone marrow response underwent to SCT only if a matched sibling donor was available. The probability of event-free survival (EFS) and overall survival were constructed using the Kaplan-Meier method. Events in the analysis of EFS included induction failure, death, relapse and secondary malignant neoplasm. All statistical analyses were done according to intent-to treat methods. RESULTS: Estimated 4-year EFS and OS for all 1252 patients was 83.7% (SE=1.1) and 90.3% (SE=0.89), slightly better in EFS than the former study (ALL-97; 79.3%, SE=1.7, p=0.054). The SR group (N=457, 37%) achieved excellent 4-year EFS of 90.4% (95%CI: 87.2, 92.7) and 4-year OS 97.3% (95.3, 98.5); in SR without slow early bone marrow response, patients with hyperdiploid and triple trisomy showed excellent 4-year EFS/OS of 100%. In the HR group (N=542, 43%), the estimated 4-year EFS and 4-year OS were 84.9% (81.5, 87.7) and 89.3% (86.3, 91.6), respectively; older age (≥ 6 years) was predictive for inferior OS (hazard ratio=1.14, p CONCLUSIONS: Refined stratification and risk-adjusted therapy in the JACLS ALL-02 trial can bring about the abolition of prophylactic CRT in non-T ALL and the optimized indication of SCT without compromising the treatment results. Disclosures No relevant conflicts of interest to declare.

Introduction B-progenitor acute lymphoblastic leukemia (B-ALLs) accounts for 85% of pediatric ALL and categorized into several molecular subgroups according to their ploidy and recurrent translocations, such as ETV6-RUNX1, TCF3-PBX1, BCR-ABL1, and MLL-rearrangements. In addition, recent genetic studies using high-throughput sequencing have disclosed landscapes of gene alterations in each subgroup, however, their clinical relevance have not fully been investigated in a large cohort of B-ALL patients who are uniformly treated and enrolled in an unbiased manner. Methods We enrolled a total of 515 pediatric B-ALL patients, who had been uniformly treated according to the Japan Association of Childhood Leukemia Study (JACLS) ALL-02 protocol between 2002 and 2008. These patients were categorized into three risk groups, including standard-, high-, and extremely high-risk. Infantile ALL as well as BCR-ABL1-positive and Down syndrome-associated cases were excluded. A total of 158 known or putative driver genes in pediatric ALL were analyzed for somatic mutations by targeted-capture sequencing. IgH rearrangements were captured using 662 baits tiling the entire IgH enhancer locus. Finally, an additional 1205 baits was also designed to enable sequencing-based genome-wide copy number detection. Results The median age at diagnosis and observation period were 5.2 (1-18.5) and 4.2 (1.8-9) years, respectively. Sixty-six of the 515 patients (13%) had relapsed diseases and 47 patients (9%) had been died. Real-time RT-PCR and conventional cytogenetic analyses revealed subgroup-defining genetic lesions in 368/515 (71%) patients: 117 (23%) cases with ETV6-RUNX1, 48 (9%) with TCF3-PBX1, 13 (3%) with MLL rearrangements, together with those with hyper- (169 [33%]), and hypo- (6 [1%]) diploid. Remaining 162 patients (31%) had none of these abnormalities. The mean depth of the targeted sequencing was 569× across the entire cohort. In total, 823 driver mutations (median 1 per patient, range 0-7) and 954 focal deletions (median 2 per patient, range 0-13) were detected in 483 patients (92%). Among these, most frequently detected were mutations/deletions in CDKN2A (24%), ETV6 (21%), NRAS (18%), KRAS (18%), and PAX5 (15%). IgH-rearrangements were detected in 51 patients, including IGH-DUX4 (26 [5.0%]), IGH-EPOR (3 [0.6%]) and IGH-CRLF2(2 [0.3%]). Genetic alterations were enriched in several functional pathways, of which most frequent was epigenetic regulation (53%), followed by B-cell development (47%), RAS signaling (46%) and cell cycle (40%). A number of novel recurrent genetic lesions were also identified, including those in DOT1L and PHF6. DOT1L encode an H3K79 methyltransferase and was inactivated by frameshift/nonsense mutations and/or deletions in 19 cases. Although frequently found in T-ALL, mutations of PHF6 had not previously been reported in B-ALL but were detected in 14 cases in the current cohort and strongly associated with TCF3-PBX1 translocation. Significant positive correlations were also demonstrated for an additional 10 combinations of common genetic lesions, suggesting functional links between these combinations. Thus, ERG deletions were highly associated with IGH-DUX4 rearrangement, while mutations in KRAS, NRAS, and CREBBP were significantly enriched in hyperdiploid cases. ETV6-RUNX1 fusion also showed positive correlations with alterations in ETV6, CDKN1B, ATF7IP, VPREB1, BTG1, and WHSC1. Furthermore, mutually exclusive relationship between ETV6-RUNX1 translocationsand FLT3mutations were also identified. Finally, we analyzed the prognostic impact of driver mutations. In multivariate analysis of the entire cohort, 4 genetic alterations were significantly associated with poor prognosis (HR [95%CI]): IKZF1 mutations/deletions (2.6 [1.5−4.8]), EBF1 deletions (3.0 [1.4−6.5]), KDM6A mutations/deletions (2.8 [1.2−6.5]), and TP53 mutations (2.7 [1.2−5.9]). Additional factors (q < 0.1) were identified in subgroup analyses, including alterations in ETV6 (5.4 [1.2−24]), CDKN1B (7.4 [1.6−33]) and CDKN2A (4.2 [1.4−12]) in ETV6-RUNX1 ALL, KMT2D (5.9 [1.3−26]) in TCF3-PBX1 ALLand TP53 (38 [4.1−364]) in IGH-DUX4ALL. Conclusions We revealed the landscape of genetic lesions in pediatric B-ALL including novel targets of recurrent mutations with clinical relevance of common genetic lesions. Our results should help in the better stratification of patients. Disclosures Ogawa: Kan research institute: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy, Research Funding; Sumitomo Dainippon Pharma: Research Funding.

Background: It is important to establish proper intensity of chemotherapeutic regimen for low risk group of childhood B-precursor ALL (BCP-ALL) to avoid late effects. For this purpose, in Japan Association of Childhood Leukemia study (JACLS) ALL-02 clinical trial, we defined standard risk (SR) group as the patients ranged from 1 to 10 years showing white blood cell (WBC) count of less than 10,000/μL at the diagnosis without predonisolone poor responder, t(4;11), t(1;19) and CNS3 to treat with less intensive chemotherapy (JACLS ALL02 SR protocol). Herein, we report the outcome of JACLS ALL02 SR protocol and analyzed prognostic factors to identify super low risk group which is curable by less intensive chemotherapy. Patientss and treatment: JACLS ALL02 SR protocol consisted of early phase therapies for total 4 months including an induction therapy using vincristine (VCR), steroids, pirarubicin (THP-ADR), and L-asparaginase (L-asp) for 4 weeks, a consolidation therapy using cyclophosphamide and a combined administration of cytarabine and dexamethasone (DEX) or 6-mercaptopurine (6-MP), a sanctuary therapy with only two cycles of high-dose methotrexate (MTX) of 3g/m2, one course of 4 drugs re-induction therapy and maintenance phase with 6-MP and oral MTX combined with VCR and PSL every 5 weeks by the end of the second year. In addition, total of 12 times of triple intrathecal therapy were administered by the end of the first year. Estimation of event free survival (EFS) and overall survival (OS) was performed using the Kaplan-Meier method and the differences were compared using the log-rank test. Multivariate analysis was performed using a Cox regression model. Results: 1252 newly diagnosed ALL patients were enrolled from April 2002 to May 2008 in JACLS ALL02 clinical trial, which include 388 patients (192 males and 196 females) in SR group (31.0%). The median age at diagnosis was 4.2 years (range, 1.0 to 9.9 years) and the median WBC count was 3,700/μL (range, 370 to 9,984 /μL). The median follow-up time was 6 year and 5 months. 4y / 8y EFS and OS (±SE) of the SR group are 91.5±1.4% / 89.4±1.7% and 97.9±0.7% / 95.2±1.2%, respectively. 4y / 8y EFS of the patients of 1 to 5 years old (n=300) and 6 to 9 years old (n=88) are 93.5±1.4% / 93.0±1.5% and 84.9±3.9% / 75.8±5.8%, respectively (log rank p=0.0003). 4y / 8y EFS of the patients with day 15 M1 marrow (n=287 ) was 92.8±1.6% / 91.6±1.8%, while those of the patients with day 15 M2 marrow (n=101) was 88.0±3.3% / 83.7±3.9% (log rank p=0.0446). When 388 patients were further classified into 4 subgroups based on genetic abnormalities, such as ETV6-RUNX1 (n=89, 22.9%), high hyperdiploid (HHD) (n=97, 25%), normal karyotype (n=147, 37.9%), and others (n=55, 14.2%), 4y-EFS/OS of each group was 97.6±5.9 /100% (ETV6-RUNX1), 91.5±2.9 /100% (HHD), 89.6±2.5 /95.1±1.8% (normal karyotype), and 86.9±4.6 /98.2±1.8% (others), suggesting poor EFS of B-others group. When HHD subgroup was divided into two groups, such as triple trisomy (TT; n=35) (trisomy of chromosome 4,10,17) and non-TT (n=62), 4y-EFS of each sub-group was 100% and 84.5±4.5%, respectively (log rank p=0.0161). Interestingly, day 15 M2 marrow was associated with poor 4y/8y EFS only in the normal karyotype subgroup (day 15 M1 vs M2 92.0±2.6% / 90.2±3.1% vs, 81.3±6.9% / 77.2±7.7%, log rank p=0.0497). The rates for NCI-CTC grade 4 infection, allergy, increase of transaminase were 1.80%, 0.26%, and 22.9%, respectively. Multivariate analysis identifies the patients of 6 to 9 years old (HR=3.178, p= Discussion: Although JACLS ALL-02 SR protocol was less intensive chemotherapeutic regimen compared to the contemporary protocols used for NCI-SR patients, good outcome of the 4y EFS and OS (91.5±1.4 % and 97.9±0.7 %) was achieved with good feasibility. Because the specific genetic subgroups such as B-others and HHD without TT were associated with relatively poor outcome, those patients should be treated with more intensive chemotherapy, especially for the patients showing initial poor response (day 15 M2). On the other hand, ETV6-RNUX1 and TT subgroups showed excellent outcome. Thus, appropriate reduction of therapy should be explored for these subgroups. Disclosures No relevant conflicts of interest to declare.

Introduction Hematopoietic stem cell transplantation (HSCT) from an HLA-matched related donor is a first-line treatment for children with severe aplastic anemia (SAA). HSCT from an HLA-matched unrelated donor (MUD) is indicated as a salvage treatment for non-responders to immunosuppressive therapy (IST).Because unrelated cord blood transplantation (UCBT) has been considered as an experimental therapy, information of UCBT in patients with SAA is scarce, especially in pediatric patients. We analyzed the outcomes of UCBT in children with AA registered in the Transplant Registry Unified Management Program (TRUMP) conducted by the Japanese Society for Hematopoietic Cell Transplantation. Patients and Methods Between 1998 and 2013, 27 patients Results Patients' characteristics Among the 27 patients, 10 patients underwent UCBT during 1998 - 2005 and 17 patients underwent UCBT during 2006 - 2013. The median age at the time of UCBT was 6 years (range, 0 - 14). The male/female ratio was 12/15. The median interval between the diagnosis of AA and CBT was 212 days (range, 39 - 2,982). Sixteen patients received antithymocyte globulin (ATG) as immunosuppressive therapy (IST) before UCBT. The median total nucleated cell number and CD34 positive cell number at cryopreservation were 3.99 x 107/kg (range, 0.09 - 16.11 x 107/kg) and 1.31 x 105/kg (range, 0.39 - 6.17 x 105/kg), respectively. Ten patients received fludarabine (FLU) + cyclophosphamide (CY) + irradiation ± ATG. Six received FLU + CY + ATG. Four received FLU + melphalan (MEL) + irradiation and the remaining 7 received other various conditioning regimens. Cyclosporine was used in 9 patients and tacrolimus was used in 17 patients for graft-versus-host disease (GVHD) prophylaxis. Transplantation outcomes Neutrophil recovery was observed in 19 patients and the median time to engraftment was 20 days. Platelets engraftment was observed in 17 patients and the median time to engraftment was 50 days. One patient experienced secondary GF. Sustained engraftment was observed in 18 patients. Grade II - IV acute GVHD, limited chronic GVHD, and extensive chronic GVHD were observed in 6 (26%), 2 (10%), and 2 patients (10%), respectively. With median follow-up times of 18 months after CBT, 19 of 27 patients were alive. Causes of death included bacterial/fungus infections in 3, veno-occulusive disease (VOD) in 2, EBV-LPD, hematologic malignancy, and secondary GF in each 1 patient. The 5-year overall and failure-free survival (OS, FFS) of all patients were 69.5±9.0% and 59.3±9.5%, respectively. The 5-year OS and FFS of 17 patients who underwent UCBT after 2006 was 93.8±6.1% and 76.0±10.5%, respectively. Primary GF was observed in 8 patients, including 3 who underwent UCBT during 2006 - 2013. Two patients, who underwent UCBT after 2006, received FLU + CY + ATG without irradiation and remaining one patient received CY + ATG + total body irradiation (TBI). We screened anti-HLA antibodies in 8 patients but none of them were positive. The conditioning regimens including ATG exhibited a significantly worse FFS than those without ATG (33.3±12.2 % vs 91.7±8.0 %, P=0.004). On the other hand, the conditioning regimens including irradiation exhibited a better FFS than those without irradiation (75.0±9.7 % vs 14.3±13.2 % , P=0.01). The 5 year FFS of FLU + MEL + irradiation regimen (n=4) and FLU + CY + irradiation regimen (n=10) was 100% and 90%±9.5%, respectively. Univariate analysis resulted in no statistical significant differences in OS and FFS in HLA disparities, total nucleated cell number and CD34 positive cell number at cryopreservation, and methods of GVHD prophylaxis. One patient developed secondary malignancy. Discussion Our study showed that a reduced conditioning regimen with Flu, MEL/CY and low-dose irradiation may be an optimal regimen for SAA children receiving UCBT. An important finding is that ATG has no benefit in this setting. A prospective study with larger number of patients is warranted to confirm our promising results. Disclosures Kojima: SANOFI: Honoraria, Research Funding.

Since an excellent outcome was observed in a previous study (OCLSG-94) utilizing continuous cytarabine (CA) infusion in the consolidation phase for the treatment of pediatric B cell precursor acute lymphoblastic leukemia (BCP-ALL), a randomization trial was performed to test the superiority of continuous CA infusion to conventional repeated CA injection as consolidation therapy in Japan Association of Childhood Leukemia Study (JACLS) ALL02 clinical trial. Newly diagnosed children with standard-risk (SR) or high-risk (HR) BCP-ALL excluding patients with Ph+ ALL and infants were included in this study. Patients showing prednisolone good response (PGR) were assigned to SR or HR based on the age at onset and initial white blood cell (WBC) counts (SR: age 1 to 9 and WBC less than 10,000 /µL, HR: remaining patients). Patients achieving complete remission (CR) at the end of induction (day 33) proceeded to the randomization. HR patients with M3 marrow on day 15 were excluded. They were randomly assigned to Arm A (cyclophosphamide 750 mg/m(2) 1hr div: day 1 and 8, CA 75 mg/m(2) 1hr div: day 1-6, 8-13 and 6MP 50 mg/m(2) orally, day 1-14) or Arm B (cyclophosphamide 500 mg/m(2) 1hr div: day 1, 3 and 5, CA 100 mg/m(2) 24hr div: day 1-5 and DEX 5 mg/m(2) 1hr div twice a day, day 1-5). Intrathecal chemotherapy (MTX, HDC and CA) was administered twice in this phase in both arms. In the HR group two doses of pirarubicin (25 mg/m (2)) were added and this phase was repeated after re-induction therapy. Estimation of event free survival (EFS) and overall survival (OS) was performed using the Kaplan-Meier method and the differences were compared using the log-rank test. Between April 2002 and May 2008, 1252 children with newly diagnosed ALL were enrolled to JACLS ALL-02 study. Among these, the number of patients with SR and HR were 388 (arm A=200, arm B=188) and 513 (arm A=251, arm B=257, not assigned=5), respectively. The characteristics of eligible patients between arm A and B were not different statistically (Table). Among SR patients, the 4y-EFS were 89.7 +/- 5.2% and 93.4 +/- 4.7% in Arm A and B, respectively (p=0.70). Among HR patients, the 4y-EFS were 89.7 +/- 5.2% and 90.5 +/- 4.4% in Arm A and B, respectively (p=0.97). Although hematological toxicity was not different, in the next phase (sanctuary phase) following Arm A consolidation therapy the frequencies of hematological grade 3 and 4 adverse effects were higher in both SR and HR (SR: p Consolidation therapy with continuous infusion of CA (Arm B) was not superior to conventional CA regimen. Disclosures No relevant conflicts of interest to declare.

SUMMARY The age-related changes in proportion of various subsets within lymphocytes were investigated in cord blood and peripheral blood from healthy children and adults. The percentages of T and B cells did not show age-related changes, whereas natural killer (NK) cells increased significantly with age. Within lymphocytes or the CD3+ T cell population the proportion of CD45RAbright+ lymphocytes decreased and that of CD45RO+ cells increased, while that of CD45RAdim+ cells showed no age-related change. Within lymphocytes, the percentage of CD45RAbright+ CD4+ cells decreased, together with a decline of that of CD4+ cells. The proportions of CD45RAbright+ CD8+ cells and S6F1bright+ CD8+ cells increased with age, and the age-dependent increase of the proportion of CD8+ cells seems to be mainly attributable to the increases in these subsets. The CD45RAdim+ CD4+ and CD45RAdim+ CD8+ cells co-expressing CD45RO at a low level nevertheless showed no age-related changes. In γδ T cells, both δTCS1+ and δTCS1- T cells increased with age, but the δTCS1-γδ T cells increased more than the δCS1+ subset. Among lymphocytes, the percentages of CD20+, CD21+ and CD22+ cells remained similar, with no age-related changes, but the proportion of CD5+ cells within lymphocytes or B cells decreased. The proportions of CD16+ NK cells among lymphocytes increased with age, and this change was attributable to the increase of CD56+ cells.

10550Background: The efficacy, safety, and feasibility of TMZ with VP (TE) have not been evaluated in pediatric patients (pts) and those of VNR with CPA (VC) have not been confirmed in Japanese pts...

10578Background: High dose Methotrexate (HDMTX) has been a key element of standard therapies for lymphatic malignancy (ML), osteosarcoma (OS), etc. Despite optimal supportive care, delayed MTX excr...

Micafungin, an antifungal echinocandin, has been indicated for pediatric patients with invasive fungal infection (IFI) in Japan and Europe. Its efficacy in immunocompromised pediatric patients with IFI, however, has not been fully investigated.The safety and efficacy of micafungin as an antifungal therapy were analyzed in nine consecutive severe immunocompromised patients with IFI.Three patients with proven or probable Candida infections had complete response to micafungin therapy. Of the other six patients with proven, probable or possible Aspergillus infection, four had complete response and one had partial response to micafungin treatment. No severe adverse events were observed.In this small series, micafungin was effective for IFI caused by both Candida and Aspergillus species and no severe adverse events were observed in these immunocompromised patients.

A 1-year-old girl with familial hemophagocytic lymphohistiocytosis underwent umbilical cord blood transplantation. On day 24, she developed renal failure, jaundice and hemolytic anemia, and we diagnosed transplantation-associated thrombotic microangiopathy (TMA). Despite discontinuation of tacrolimus, her condition became even worse. From day 25, we started to administer recombinant human soluble thrombomodulin (rTM). According to the recommendation of the pharmaceutical company, a dose reduction from 380 to 130 IU/kg/day in patients with renal failure, we administered rTM at the reduced dose during the first 2 days. Because the reduced dose was not effective, we administered rTM at the standard dose from day 27. Surprisingly, she began to recover from TMA on the next day, and we continued to administer rTM until day 109. She is alive without evidence of disease eighteen months after transplantation. Adverse events of rTM were severe gastrointestinal hemorrhage and hemorrhagic cystitis, and it was necessary to control hemorrhage by interruption of administration. This case report suggests that rTM may be effective for TMA. Moreover, alteration in the dosage schedule seems to be required according to the condition of patients. Further studies are needed to evaluate the effectiveness and an optimal dose of rTM as a treatment for TMA.

Expression patterns of interleukin-6 (IL-6), IL-6 receptor (IL-6R), and gp130 genes in 39 patients with acute myeloid leukemia (AML), in 23 patients with acute lymphoblastic leukemia (ALL), and in 7 patients with acute mixed lineage leukemia (AMLL) were studied by quantitative reverse transcriptase-polymerase chain reaction. Significant levels of IL-6 were expressed in 8 (21%) of 39 AML patients and in 2 (29%) of 7 AMLL patients, whereas in ALL, the expression of IL-6 was almost negligible. IL-6R was expressed in all patients with AML and AMLL, whereas only half of ALL patients expressed low levels of IL-6R as compared with those with AML and AMLL. However, gp130 was ubiquitously expressed in all the leukemia patients, and there was no significant difference in gp130 expression among AML, ALL, and AMLL. Significant correlation was observed between the expression of IL-6R and gp130 in AML. When tested for in vitro response to IL-6, the leukemic cells from 3 of 7 AML, none of 3 ALL, and both of 2 AMLL patients significantly responded to IL-6, showing the correlation between the expression levels of IL-6R and gp130 and the responsiveness of leukemic cells to IL-6. These results showed that quantitation of IL-6R and gp130 expression by reverse transcriptase-polymerase chain reaction is useful for the rapid prediction of the responsiveness of leukemic cells to IL- 6, especially in cases of administration of IL-6.

By immunophenotyping and ultrastructural cytochemistry, the disorders involving megakaryocytic lineage cells have been clarified. These disorders are termed acute megakaryocytic leukemia (AMKL) and transient abnormal myelopoiesis (TAM). The characteristics of blasts in these disorders have been extensively investigated from various standpoints including cytochemistry, cytogenetics, ultrastructure and in vitro-colony differentiation. The target cells of AMKL and TAM are immature cells close to stem cells which are capable of differentiating into lineage cells such as megakaryocytes, erythrocytes and myeloid cells. Phenotypically, these blasts frequently express antigens appearing at an early stage in the hematopoietic differentiation pathway. They thus often emerge as mixed phenotypes as seen in mixed lineage leukemia of immature cell origin.

The authors present unusual clinicopathologic findings of a patient with neuroblastoma stage 4S that recurred 11 years after induction of complete remission with chemotherapy. A 12-year-old girl presented with recurrent tumor in the liver. Urinary catecholamine metabolites were within normal range in contrast to the increased values at initial presentation. She underwent left lateral segmentectomy and biopsy of the right lobe. Histologic analysis of the recurrent tumor showed undifferentiated neuroblastoma intermingled with mature ganglioneuromatous lesions. There also were scattered ganglioneuromatous lesions throughout nontumorous area of the liver. Although multimodal intensified treatments including autologous bone marrow transplantation were performed, the patient died of obstinate recurrent tumor at age 14 years. The clinicopathologic findings suggested dedifferentiation from the ganglioneuromatous lesion rather than ordinary recurrence of the primary tumor. The current case and the literature review may indicate that long-term follow-up would be necessary for neuroblastoma stage 4/4S cases. J Pediatr Surg 36:953-955. Copyright © 2001 by W.B. Saunders Company.

We present 3 patients with Crohn disease (CD) of the duodenum with progressive symptoms. A 31-year-old man with Crohn ileocolitis presented epigastralgia. A 32-year-old man with Crohn ileocolitis presented upper GI bleeding. In both patients, endoscopy revealed duodenal stenosis. A 33-year-old man was given a diagnosis of CD by gastroduodenal endoscopy. They received an infliximab infusion and had symptomatic relief and macroscopic healings without any adverse effects. Several treatments for upper GI lesions of the CD patients have been tried, but there is no high-quality level evidence-based data to guide the medical management of gastroduodenal CD. Our experience with 3 patients suggests that infliximab is a safe and effective treatment for duodenal CD and it may be appropriate for early use to avoid surgery or balloon dilatation.

We cared 28 life limiting children with cancer in the past five years. Two patients died at home and the rest of them died at hospitals. Most children older than 11 years understood their disease. On the other hand, poor prognosis at the end stage was not noticed precisely to most of them. We recommended that they spend time with their families as long as possible. There were some problems associated with going back home. Those were as follows: a decision making was difficult for the patients because some of them were very young or unconcious not awake, not enough time for the patient's family to get ready for a home palliative care, or the patients who need frequent transfusions. In palliative care of children with the end of life stage cancer, it is essential that more co-medicals and other professions should be involved in order to strive for a good quality of life.

We conducted a multicenter postmarketing study to investigate the efficacy and safety of reinduction therapy with a high-dose cytarabine-containing regimen for pediatric patients with relapsed or refractory acute leukemia. Seven of 13 patients (53.8%) with ALL achieved complete or partial remission, and only 1 of 6 patients (16.7%) with AML achieved partial remission. The frequent non-hematologic adverse events were gastrointestinal toxicities, such as vomiting, diarrhea and abdominal pain, as well as pyrexia and headache. Infection appeared in 9 of 20 (45%) patients. There were two death during reinduction therapy. One died of invasive bronchopulmonary aspergillosis, and the other died of intracranial hemorrhage and renal failure. These results indicated that a high-dose cytarabine regimen is effective as reinduction therapy in pediatric patients with relapsed ALL, and supportive care is essential to prevent or control treatment-related adverse events, such as infection.

The periosteum consists of the cells that are capable of differentiating into osteoblasts. Recently, gradually expanding the interface between bone surface and periosteum using the titanium-meshed plate has been suggested for osteogenesis. Meanwhile, the administration of mesenchymal stem cells (MSCs) into callus has been postulated for facilitating osteogenesis. We tested a novel mesh plate consisting of a mixture of poly-l-lactide (PLLA) and particulate resorbable uncalcined hydroxyapatite (u-HA) as an alternative material for the periosteal distraction in rabbits. In addition, we also performed preliminary analysis on the effect of rabbit MSCs administrated into the gap created by periosteal distraction. Histological analysis by hematoxylin and eosin staining revealed that the bone formation was successfully induced at the gap of periosteal distraction by the novel plate. The MSCs appeared to have a positive effect on the bone formation. Here, we showed that the novel PLLA/u-HA plate could be a replacement of the titanium-meshed plate in the periosteal distraction.

Recent data have elucidated the pathogenesis of transient abnormal myelopoiesis (TAM) to a great extent. TAM is a monoclonal disorder which resolves spontaneously and the target cell in this disorder is a multipotent stem cell which is capable of differentiating into megakaryocytes. The pathogeneses of TAM/AMKL (acute megakaryoblastic leukemia) appears to be closely associated with abnormal quality and quantity of a gene located on chromosome 21. AMKL developing after the regression of TAM appears to come from the same clone as the TAM, which apparently experiences some kind of genetic alterations. It seems that the gene responsible for TAM will soon be cloned in the near future. However, the mechanism of spontaneous regression of TAM has as yet not been clarified. The expanding clone in the transient physiological immunodeficient state, during the perinatal period, might be eliminated with the maturation of more mature immunosurveillance. Alternatively, the TAM clone might be destined to undergo spontaneous death, which is called "programmed cell death" (apoptosis). The mechanism of this phenomenon awaits further elucidation.

Although objects in most computer vision have been assumed to be “solid bodies,” this assumption is not always true in practice; for example, a horse can be an object. It has been known that humans recognize such an object by dividing it into several parts, each of which has a recognizable feature. This process is important also for computer processing. This paper proposes pattern recognition of a silhouette of an animal using the relative position of each part of its body. The process is to segment each region of the silhouette and to describe the characteristic of each part and the relationship between a part and its adjacent part. A new method, the “ellipsoid-expansion method,” based on an ellipsoid fitting, is proposed to segment a silhouette. This method uses an ellipse which is fitted to a region by expanding the ellipse and by producing a reaction when the expanded ellipse exceeds the contour of the region. This method is not influenced by details of the shape of the object and withstands shifts, change of scaling, and rotation of the shape. Recognition of each part of the silhouette of an animal is tested by identifying the description of each part of a basic model of the animal and the description of its silhouette. Examples of identification of animals are carried out using some simple cases.

We recently encountered a patient with acute lymphoblastic leukemia (ALL) who showed temporal monocytosis of an unusually high cell count (5,000-30,000 monocytoid cells/μ1) five times after treatment

The status of the TCR-alpha/delta genes in B-precursor ALL and the rearrangement patterns of these gene loci are discussed in this review. Although most of these rearrangements have been characterized, some still remain to be clarified. Almost all rearrangements of the TCRs in B-precursor ALL are incomplete and may reflect early recombinational steps during the TCR differentiation processes in normal T-lineage cells. In addition, even in T-cell malignancies, it is rarely possible to obtain clonal cell populations with TCR rearrangements arrested in very early recombinational steps. Therefore, studies of these as yet uncharacterized rearrangements may lead to the discovery of additional gene segments playing important roles in the TCR recombinational processes and may provide useful information for understanding the processes of T-cell differentiation.

We report a 5-year-old boy with juvenile myelomonocytic leukemia (JMML) which relapsed after an allogeneic bone marrow transplant who was successfully treated with interferon-alpha (IFN-alpha). One year after starting the therapy, he remains clinically well and in complete remission while continuing treatment with IFN-alpha and bestatin. Although the precise mechanism by which remission was induced is uncertain, a GVL effect combined with a direct antileukemia effect of IFN-alpha may be responsible. Further assessment of the role of IFN-alpha in relapsed JMLL patients is warranted.

Children with acute lymphoblastic leukemia (ALL) who fail to achieve complete remission (CR) after induction therapy (induction failure: IF) have a poor prognosis; however, there have been few prospective studies in patients with IF.Between April 1997 and March 2005, 27 of 1,237 leukemic patients (2.2%) failed to achieve CR after four- or five-drug induction therapy. Twenty-three of these patients entered the F-protocol study, which mainly consisted of acute-myeloid-leukemia-oriented chemotherapy followed by scheduled hematopoietic cell transplantation (HCT).Seventeen (73.9%) of the 23 patients responded to re-induction chemotherapy with CR. Of note, 15 (93.8%) of 16 patients with Philadelphia-chromosome-negative (non-Ph(+)) ALL achieved CR; in contrast, only 2 (28.6%) of 7 Ph(+) patients achieved CR. Fourteen (82.4%) of 17 patients remained in CR (CCR) until their scheduled HCT, 12 of the 14 with CCR underwent HCT as scheduled, and 6 patients remain in first CR after a median of 78 months (range, 49-107 months). The 5-year overall survival (OS) rates of 16 patients with non-Ph(+) and 7 patients with Ph(+) were 43.8 +/- 12.4% and 14.3 +/- 13.2%, respectively (P = 0.012). The 5-year OS rate of the 17 patients who obtained CR by re-induction therapy and the 6 who did not were 47.1 +/- 12.1% and 0%, respectively (P0.001).Acute-myeloid-leukemia-oriented chemotherapy followed by scheduled HCT is a promising treatment strategy for non-Ph(+) ALL patients with IF.

Ten leukemia cases with mixed phenotype were investigated in terms of clinical characteristics and cellular origin. Three patients were infants and six patients were older children. Six of them had a high leukocyte count and a mediastinal mass was found in three cases. All but one showed hepatosplenomegaly and/or lymphoadenopathy. In spite of intensive chemotherapy, most of them responded poorly. Cytochemical analysis of their leukemic cells revealed a low percentage of positivity for myeloperoxidase reactivity (< 25%) in two cases and electron microscopic platelet peroxidase reactivity was found in one of three analyzed cases. Phenotypically, these cells all expressed CD7, and other T-lineage-associated, B-lineage-associated, and/or myeloid-associated antigens were also detected to some extent. In addition, three cases expressed CD41 and one case expressed CD56. The T-cell receptor (TCR) genes and immunoglobulin gene were in the germline configuration in seven cases. In three rearranged cases two showed only the TCR-δ gene rearrangement, and one had both TCR-γ and δ gene rearrangements. Cell culture studies with 12–0-tetradecanoyl-phorbol-13-acetate (TPA) revealed differentiation to the T-lineage in two cases and to a myeloid lineage in one case. Megakaryocytic differentiation was detected in two cases in culture without TPA. These results suggest that the cells from these cases arose from stem cells capable of both lymphoid and nonlymphoid differentiation. Although the cells were heterogeneous with regard to their potency of differentiation, they have similar clinical characteristics. Because of poor prognosis, it is important to identify this type of leukemia, and allogenic or autologous bone marrow transplantation should be considered. Cancer 68:2273–2280, 1991.