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Key Points A total of 137 patients with JMML were analyzed using DREAM.We developed a robust DNA methylation test that is highly consistent with the array-based international consensus definition for JMML., Visual Abstract, Juvenile myelomonocytic leukemia (JMML) is a rare myelodysplastic/myeloproliferative neoplasm that develops during infancy and early childhood. The array-based international consensus definition of DNA methylation has recently classified patients with JMML into the following 3 groups: high (HM), intermediate (IM), and low methylation (LM). To develop a simple and robust methylation clinical test, 137 patients with JMML were analyzed using the Digital Restriction Enzyme Analysis of Methylation (DREAM), which is a next-generation sequencing–based methylation analysis. Unsupervised consensus clustering of the discovery cohort (n = 99) using DREAM data identified HM (HM_DREAM; n = 35) and LM subgroups (LM_DREAM; n = 64). Of the 98 cases that could be compared with the international consensus classification, 90 HM (n = 30) and LM (n = 60) cases had 100% concordance with DREAM clustering results. Of the remaining 8 cases comprising the IM group, 4 were classified as belonging to the HM_DREAM group and 4 to the LM_DREAM group. A machine-learning classifier was successfully constructed using a support vector machine (SVM), which divided the validation cohort (n = 38) into HM (HM_SVM, n = 18) and LM (LM_SVM; n = 20) groups. Patients with the HM_SVM profile had a significantly poorer 5-year overall survival rate than those with the LM_SVM profile. In conclusion, we developed a robust methylation test using DREAM for patients with JMML. This simple and straightforward test can be easily incorporated into diagnosis to generate a methylation classification for patients so they can receive risk-adapted treatment in the context of future clinical trials.

Objectives Patients with acquired aplastic anemia (AA) without HLA-matched sibling donors or aged >40 years receive immunosuppressive therapy (IST) with anti-thymocyte globulin (ATG). We investigated the relationship between plasma rabbit ATG (r-ATG) concentration and IST response. Methods From May 2012 to October 2017, 81 patients with severe AA who required initial IST were included. A 1:1 block randomization was employed for 2.5 and 3.5 mg/kg doses of r-ATG. Results No significant difference in response rates was observed between the 2.5 and 3.5 mg/kg groups (63% vs. 58%, P = .894). Median r-ATG concentrations on days 14 and 28 after IST were 15.2 (0.0-97.7) and 1.8 (0.0-74.9 µg/mL), respectively. According to r-ATG concentration, response rates were significantly higher in the group with higher r-ATG concentration than in those with lower r-ATG concentration (day 14, 88% vs. 52%; P = .006 and day 28, 79% vs. 46%; P = .005). In multivariate analysis, higher r-ATG concentrations at day 28 were independent predictors of favorable response to IST at 6 months (odds ratio, 0.29; 95% confidence interval, 0.09-0.93; P = .037). Conclusions The present data indicate that higher r-ATG concentration at day 28 resulted in improved IST response.

Aim: There may exist a gap between the current form of traditional Japanese Kampo pediatrics and Kampo pediatrics in the nineteenth century. This study aimed to elucidate changes in clinical practice by comparing the formulas used then and now. Methods: All formulas described in Yoyokasoku (In‐house Methods of Pediatrics [IMP], a Kampo classic published in 1885) and formulas used in a contemporary pediatric Kampo guideline were extracted. Then, a database with annotations to formulas was compiled. Results: In all, 387 formulas (274 excluding duplications) and 10 methods of moxibustion/surgical treatments were extracted from IMP. The total number of classical formulas described was 72. The proportion of classical formulas was significantly different among disease clusters (P, Version of Record online: 02 November 2020 ファイル公開：2021-11-02

Pediatric solid tumors are a heterogeneous group of neoplasms with over 100 subtypes. Clinical and histopathological diagnosis remains challenging due to the overlapping morphological and immunohistochemical findings and the presence of atypical cases. To evaluate the potential utility of including RNA-sequencing (RNA-seq) in the diagnostic process, we performed RNA-seq in 47 patients with suspected pediatric sarcomas. Histopathologists specialized in pediatric cancer re-evaluated pathological specimens to reach a consensus diagnosis; 42 patients were diagnosed with known subtypes of solid tumors whereas 5 patients were diagnosed with undifferentiated sarcoma. RNA-seq analysis confirmed and refined consensus diagnoses and further identified diagnostic genetic variants in four of the five patients with undifferentiated sarcoma. Genetic lesions were detected in 23 patients, including the novel SMARCA4-THOP1 fusion gene and 22 conventional or recently reported genetic events. Unsupervised clustering analysis of the RNA-seq data identified a distinct cluster defined by the overexpression of rhabdomyosarcoma-associated genes including MYOG and CHRNG. These findings suggest that RNA-seq-based genetic analysis may aid in the diagnosis of suspected pediatric sarcomas, which would be useful for the development of stratified treatment strategies.

Pulmonary hypertension (PH) is associated with high morbidity in children undergoing hematopoietic stem cell transplantation (HSCT). However, owing to the lack of sequential echocardiography, the nature of the condition is not fully understood. This study was conducted to investigate whether routine echocardiography performed after HSCT could detect patients with PH at an earlier stage and elucidate the role of intervention using tadalafil. The study population comprised 93 consecutive children age18 years who underwent a total of 109 HSCTs. All patients underwent routine transthoracic echocardiography during HSCT. Four children (4%) with a median age of 4 years (range, 0.7 to 6 years) were found to have PH, and their median tricuspid regurgitation peak velocity (TRV) was 4.1 m/s (range, 3.5 to 4.2 m/s). PH was diagnosed at a median of 52 days (range, 21 to 118 days) after HSCT. Three of them were diagnosed with neuroblastoma, and 1 was diagnosed with infantile leukemia. One patient developed PH after autologous HSCT, and 3 received killer immunoglobulin-like receptor ligand-mismatched cord blood. Busulfan was used for conditioning in all patients, and the proportion of patients receiving this medication was significantly higher in the PH group compared with the non-PH group (100% versus 30%; P = .011). Three of the 4 patients had a durable response (TRV ≤2.8 m/s) at a median of 46 days (range, 14 to 79 days) after starting treatment with tadalafil. No patient experienced exacerbation of PH, and treatment was completed at median of 96 days (range, 46 to 212 days). Our data suggest that routine echocardiography monitoring after HSCT should be considered in children receiving busulfan, although the precise follow-up timing needs further study. In addition, safe and effective administration of tadalafil must be ensured by close monitoring.

Objective: The prognosis of adrenoleukodystrophy (ALD)with neurological involvement is generally dismal; however, allogeneic stem cell transplantation (SCT) is recognized as effective to stabilize or improve the clinical symptoms of ALD. Herein, we report the clinical outcomes of patients with ALD who consecutively underwent allogeneic stem cell transplantation with reduced intensity conditioning at our institution. Patients: Sixteen patients with ALD, who were symptomatic (n = 14) or presymptomatic (n = 2), received SCT from 2010 to 2016. The stem cell source was cord blood (n = 14), or bone marrow from a human leukocyte antigen identical sibling (n = 2). The conditioning regimen prior to transplantation was reduced intensity and consisted of fludarabine (125 mg/m2), melphalan (140 mg/m2) and low dose total body irradiation (TBI) of 4Gy (n = 15) or 3Gy (n = 1). Results: Primary engraftment was obtained in 11 patients, and 4 of the 5 patients who lost the primary graft received a second cord blood transplantation and were engrafted. Five years overall and event-free survival were 90.9% and 61.1% respectively, with a median of 45 months (range 16–91). Loes score stabilized or improved by 18 months after transplantation except for patients with internal capsule involvement. Conclusion: Allogeneic SCT with reduced intensity conditioning for patients with ALD was safely performed without major transplant-related complications even in symptomatic patients and neurological symptoms were stabilized after SCT in patients without internal capsule involvement. Keywords: Adrenoleukodystrophy, Allogeneic stem cell transplantation, Loes score, Very long chain fatty acid

We investigated the safety and efficacy of mycophenolate mofetil (MMF) in the prevention and treatment of graft-versus-host disease (GVHD) using a nationwide retrospective survey in Japanese children undergoing hematopoietic stem cell transplantation (HSCT). Overall, 141 children undergoing allogeneic HSCT for hematological malignancy (n = 84), non-malignancy (n = 52), and solid tumors (n = 5) were administered MMF orally (median 8 years; range 0-15 years; 89 males and 52 females) during 1995-2011. Donors were primarily unrelated and mismatched related. In the GVHD prophylaxis group, 29% and 8.6% of patients developed grade II-IV and III-IV GVHD, respectively. Of the 32 evaluable patients, 16% developed chronic [limited (n = 4) and extensive (n = 1)] GVHD. In the acute GVHD treatment group, 61% had decreased grade. In the chronic GVHD treatment group, 36% had improved symptoms. Combined immunosuppressant was reduced or discontinued in 61% patients. Major adverse events (AEs) were neutropenia (4.3%), infection (3.5%), thrombocytopenia (2.1%), myelosuppression (2.1%), and diarrhea (1.4%). MMF dosage was reduced in two children due to grade ≥ 3 AEs; two children died from infection. MMF thus may be well tolerated in children, and may be an effective option for prophylaxis and treatment of acute and chronic GVHD.

Background: Patients with relapsed or refractory neuroblastoma have a poor prognosis; there are limited effective and safe rescue chemotherapies for these patients. Development of new chemotherapy regimens for these patients is a key imperative. Procedure: We retrospectively analyzed patients with refractory or relapsed neuroblastoma who received irinotecan, etoposide, and carboplatin (IREC) as a second-line treatment for neuroblastoma. We evaluated the therapeutic response, toxicity, and survival outcomes. We also assessed the impact of UGT1A1 gene polymorphisms, which are involved in irinotecan metabolism, on the outcomes and toxicity. Results: A total of 131 cycles of IREC were administered to 43 patients with a median of two cycles per patient (range, 1–10). All patients were classified as high-risk (International Neuroblastoma Risk Group). Seven patients had relapsed before IREC. One patient (2%) showed partial response and 37 patients (86%) developed stable disease (disease control rate: 88%). Grade IV neutropenia was observed in 127 cycles (97%), while ≥ grade III gastrointestinal toxicity was observed in 3 cycles (2%). There was no IREC-related mortality. The one-year overall survival and progression-free survival rates were 65% and 52%, respectively. Patients with UGT1A1 polymorphisms showed a higher frequency of grade IV neutropenia; however, there was no increase in treatment-related mortality or nonhematological toxicity in these patients. Patients with UGT1A1 gene polymorphisms showed better one-year survival rate than the wild type (80% vs. 44%, p = 0.012). Conclusions: This study suggests that IREC is well-tolerated by patients with UGT1A1 polymorphisms and is a promising second-line chemotherapy for refractory/relapsed neuroblastoma.

Background: Central venous catheters (CVCs) have been essential devices for the treatment of children with hematological and oncological disorders. Only few studies investigated the complications and selections of different types of CVCs in these pediatric patients. This study aimed to compare risk factors for unplanned removal of two commonly used CVCs, i.e., peripherally inserted central catheters (PICCs) and tunneled CVCs, and propose better device selection for the patient. Procedure: This retrospective, single center cohort analysis was conducted on pediatric patients with hematological and oncological disorders inserted with either a PICC or a tunneled CVC. Results: Between January 1, 2013, and December 31, 2015, 89 patients inserted with tunneled CVCs (total 21,395 catheter-days) and 84 with PICCs (total 9,177 catheter-days) were followed up until the catheter removal. The median duration of catheterization was 88 days in PICCs and 186 days in tunneled CVCs (p = 1.24×10-9). PICCs at the 3-month cumulative incidence of catheter occlusion (5.2% vs. 0%, p = 4.08×10-3) and total unplanned removal (29.0% vs 7.0%, p = 0.0316) were significantly higher, whereas no significant difference was observed in the cumulative incidence of central line-associated bloodstream infection (11.8% vs. 2.3%, p = 0.664). Multivariable analysis identified younger age (

In patients with acquired AA, PGF is a major cause of cytopenia after hematopoietic stem cell transplantation. An increased incidence of PGF, especially sPGF, has been noted after the introduction of the FLU/CY regimen in children with acquired AA. To clarify the risk factors for sPGF, the clinical data of 49 patients (median age, 11 years; range, 1-19 years) with AA who received allogeneic BMT at Nagoya University Hospital from 1997 to 2016 were analyzed. Out of the 49 patients, 7 developed sPGF, and the 5-year CI was 0.15 (95% CI, 0.04-0.25). Five received the FLU/CY regimen, and the 5-year CI of sPGF was significantly higher in patients who received the regimen (0.36; 95% CI, 0.12-0.62) than in those who were conditioned with the non-FLU/CY regimen (0.06; 95% CI, 0.01-0.17; P = .01). The multivariate analysis confirmed that the FLU/CY regimen (hazard ratio, 6.12; 95% CI, 1.16-32.4; P = .03) was a significant risk factor for sPGF. sPGF improved spontaneously without stem cell boost infusions in 5 patients, ranging from 460 to 3539 days after BMT. The 10-year CI of the spontaneous trilineage recovery was 0.83 (95% CI, 0.00-0.97), and all 7 patients are alive. The FLU/CY regimen was identified as a risk factor for the sPGF development in patients with AA. The establishment of the optimal conditioning regimens for children with AA is warranted.

Congenital dyserythropoietic anemia (CDA) is a heterogeneous group of rare congenital disorders characterized by ineffective erythropoiesis and dysplastic changes in erythroblasts. Diagnosis of CDA is based primarily on the morphology of bone marrow erythroblasts; however, genetic tests have recently become more important. Here, we performed genetic analysis of 10 Japanese patients who had been diagnosed with CDA based on laboratory findings and morphological characteristics. We examined 10 CDA patients via central review of bone marrow morphology and genetic analysis for congenital bone marrow failure syndromes. Sanger sequencing for CDAN1, SEC23B, and KLF1 was performed for all patients. We performed whole-exome sequencing in patients without mutation in these genes. Three patients carried pathogenic CDAN1 mutations, whereas no SEC23B mutations were identified in our cohort. WES unexpectedly identified gene mutations known to cause congenital hemolytic anemia in two patients: canonical G6PD p.Val394Leu mutation and SPTA1 p.Arg28His mutation. Comprehensive genetic analysis is warranted for more effective diagnosis of patients with suspected CDA.

Introduction Head hair is a symbol of vitality, and hair loss by alopecia areata (AA) presents a burden on patients. Although traditional Japanese Kampo medicine (JKM) formulas, acupuncture, and moxibustion have historically been used for treating AA, no studies have utilized a combination of these modalities. Patient concerns A 34-year-old male with a history of childhood asthma presented with a sudden hair loss at the top of his head without any preceding symptoms. Except for a hairless patch of 5 cm × 6 cm, his general appearance was otherwise good. The patient underwent topical immunotherapy on visiting a dermatologist. However, the patient noticed an exacerbation of his hairless lesion. Diagnosis The AA diagnosis was established based on clinical appearance and dermatological findings. The Severity of Alopecia Tool (SALT) score for alopecia was 19% at diagnosis. Interventions The patient received 2 JKM formulas (saikokaryukotsuboreito and shichimotsukokato) in combination with acupuncture. When relapse occurred, a novel self-administration of pine-needle acupuncture was initiated in combination with the JKM formulas. Outcomes A 50% recovery from the baseline SALT score was achieved using JKM formulas in combination with acupuncture for 4 months. The patient achieved complete remission for 5 months. However, another stressful event induced an AA relapse with multiple lesions harboring a SALT score of 13%. Pine-needle acupuncture was initiated, resulting in faster resolution than the first treatment. Recoveries of 50% and 75% were achieved 3 and 4 months after relapse, respectively, and a long-lasting response without relapse was obtained for at least 3 years. Conclusion A combination of multimodal traditional therapies, including JKM formulas, acupuncture, and self-administered pine-needle stimulation, represents an effective integrative treatment for patients with AA.

BACKGROUND: Inherited bone marrow failure syndromes (IBMFSs) are a heterogeneous group of genetic disorders characterized by bone marrow failure, physical anomalies, and various kinds of organ complications. In addition to classical IBMFSs, such as Fanconi anemia, Diamond-Blackfan anemia, Dyskeratosis congenita, Shwachman-Diamond syndrome, and familial platelet disorders, many types of unclassified IBMFSs are reported. Over 100 genes are considered causative genes; however, the precise genetic diagnosis of IBMFSs remains challenging. We developed a capture-based target sequencing method for IBMFSs that covers more than 180 associated genes. Our system achieved genetic diagnosis for 225 (35%) of 738 patients between 2013 and 2018. However, the causative gene remained unknown for 513 (65%) patients, and further genetic analysis of these "target-negative" cases was necessary to achieve a precise diagnosis. METHODS: We performed whole exome sequencing (WES) for patients who were "target-negative" but strongly suspected of having IBMFS based on the following clinical characteristics: physical or organ anomalies (skin, nail, hair, skeletal, growth, cardiac, lung, liver, or genitourinary), family history of hematological disorder, young age (≤2 years), short telomere length ( RESULTS: Among the 513 "target-negative" cases, 166 patients were evaluated, of whom 17 patients' parents were also analyzed in a trio-based analysis. New pathogenic variants were identified in 18 of the 166 (11%) patients according to the American College of Medical Genetics (ACMG) guidelines, of which 5 variants were revealed to be de novo. Diagnostic variants were identified in FANCF, SRP54, RPL19, RPL5, RTEL1, RUNX1, MECOM, CDC42, GNE, SLNF14 (all n = 1). In addition to IBMFS-associated genes, causative genes for congenital hemolytic anemia (G6PD, PKLR), inborn error of metabolism (SLC46A1), and primary immune deficiency (NFKB2, LRBA) are also identified (all n = 1). Moreover, loss-of-function mutation of ADH5 gene are identified in three patients that seems to be associated to novel IBMFSs. On the other hand, no pathogenic variant in GATA2, ERCC6L2, LIG4, and SAMD9/SAMD9L genes that are reported as unclassified IBMFSs in Europe and United States are identified in our cohort. CONCLUSION: Our findings support the utility of WES (especially trio-based analysis) as a diagnostic tool for IBMFSs. Furthermore, genetic background of IBMFSs in East Asia seems to be different from that of Europe and United States. Disclosures No relevant conflicts of interest to declare.

Background Distinguishing hypocellular refractory cytopenia of childhood (RCC) from aplastic anemia (AA) is challenging. Thus far, no studies have compared the cytokine profiles in patients with AA to those with hypocellular RCC. In the present study, we addressed whether thrombopoietin (TPO) and interleukin 17 (IL-17) plasma levels are useful for differentiating between the two diseases. Methods We measured the endogenous plasma concentrations of TPO and IL-17 in 29 patients with AA, 34 patients with hypocellular RCC, and 31 healthy controls using sensitive enzyme-linked immunosorbent assays. Results The TPO and IL-17 plasma levels were significantly lower in patients with hypocellular RCC than in patients with AA (P < 0.001 and P = 0.007, respectively). The multivariate logistic regression analysis identified moderate disease severity, TPO levels of

Introduction: Aplastic anemia (AA) is an autoimmune-mediated disease with a complex mechanism. Innate as well as acquired immune system have been considered to participate in its pathogenesis. Although several studies have demonstrated the role of T and B cells in AA, there is limited research focusing on natural killer (NK) cells, which are important in innate and adaptive immune system. NK cells interact with T cells and alter their immune responses in a variety of diseases. Recent investigation suggests that NK cells serve immunoregulatory roles by attenuating autologous CD8+ T-cell response in AA (Chen et al. Cell Immunol 335:6-14, 2019). Here we assessed the kinetics of NK cells before and after immunosuppressive therapy (IST) in patients with AA to determine the association between NK cells and clinical courses. Methods: Patients with severe AA, in Japan, who required IST as first-line therapy were prospectively enrolled between May 2012 and October 2017. The IST regimen comprised rabbit anti-thymocyte globulin (ATG, thymoglobulin®, 2.5 or 3.5 mg/kg/day for 5 days), cyclosporine A (6 mg/kg/day for minimum 6 months), and methylprednisolone (2 mg/kg/day for 5 days) with subsequent tapering of the dose for 28 days. Flow cytometry was used to assess lymphocyte subsets, consisting of CD3+, CD4+, and CD8+ T cells, CD19+ B cells, CD56+ NK cells, and CD4+CD25+CD127+ regulatory T cells (Tregs), before and after ATG administration on days 0, 14, 28, 60, 90, 120, and 180. Plasma rabbit ATG levels were measured using a rabbit IgG ELISA kit on days 14 and 28 (Bethyl Laboratories, Montgomery, TX, USA). Receiver-operator characteristic (ROC) curves were generated to differentiate between response and no response to IST. Results: A total of 81 patients (aged 1.7-67.9 years) were randomized; 43 and 38 patients received 2.5 and 3.5 mg/kg of r-ATG, respectively. Median follow-up duration was 445 days (range; 183-2165 days) from first ATG infusion. After 6 months, 50 patients (58%) responded to the therapy, including 4 (5%) who achieved a complete response and 45 (56%) a partial response. The response rates did not differ significantly between the two dosages in ATG groups at 6 months (2.5 mg/kg, 63% vs. 3.5 mg/kg, 58%, P = 0.820). The median absolute number of NK cells before IST was 92/µL (0-1,085/µL). To judge patients' responses to IST, we defined 138/µL as the absolute number of NK cells count before IST as the cut-off value using ROC curves. The response rate of patients with higher NK cells (≥ 138 /mL) to IST at 6 months was significantly higher than those with lower NK cells (Figure 1, < 138 /mL, 78% vs. 52%, P = 0.031). Multivariate logistic regression analysis identified the absolute number of NK cells before IST and reticulocyte at diagnosis (odds ratio [OR] = 0.16; 95% confidence interval [CI], 0.04-0.62; P = 0.008 and OR = 0.20; 95% CI, 0.06-0.67; P = 0.009, respectively) and the r-ATG plasma concentration on day 28 (OR = 0.11; 95% CI, 0.03-0.39; P = 0.001) as independent predictors of response to IST. The median absolute number of NK cells on days 90, 120, and 180 after IST was higher in the responders (113/mL, 118/mL, and 159/mL, respectively) than in the non-responders (57/mL, 53/mL, and 64/mL, P = 0.001, P Conclusions: The current study indicates that NK cells play a role in the pathogenesis of AA and may be the predictors of response to IST. Recovery of NK cell count correlated with hematopoietic recovery following IST, indicating that they may be used as markers to assess disease activity, treatment response and relapse. Disclosures Yamazaki: Novartis Pharma K.K.: Honoraria; Sanofi K.K.: Honoraria; Nippon Shinyaku Co., Ltd.: Honoraria. Nakao:Ono Pharmaceutical: Honoraria; Kyowa Kirin: Honoraria; Alaxion Pharmaceuticals: Honoraria; Ohtsuka Pharmaceutical: Honoraria; Celgene: Honoraria; Daiichi-Sankyo Company, Limited: Honoraria; Janssen Pharmaceutical K.K.: Honoraria; SynBio Pharmaceuticals: Consultancy; Novartis Pharma K.K: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda Pharmaceutical Company Limited: Honoraria; Chugai Pharmaceutical Co.,Ltd: Honoraria.

Therapy for BK virus (BKV)–associated hemorrhagic cystitis (BKV-HC) is limited after hematopoietic stem cell transplantation (HSCT). We examined whether choreito, a formula from Japanese traditional Kampo medicine, is effective for treating BKV-HC. Among children who underwent allogeneic HSCT between October 2006 and March 2014, 14 were diagnosed with BKV-HC (median, 36 days; range, 14 to 330 days) after HSCT, and 6 consecutive children received pharmaceutical-grade choreito extract granules. The hematuria grade before treatment was significantly higher in the choreito group than in the nonchoreito group (P = .018). The duration from therapy to complete resolution was significantly shorter in the choreito group (median, 9 days; range, 4 to 17 days) than in the nonchoreito group (median, 17 days; range, 15 to 66 days; P = .037). In 11 children with macroscopic hematuria, the duration from treatment to resolution of macroscopic hematuria was significantly shorter in the choreito group than in the nonchoreito group (median, 2 days versus 11 days; P = .0043). The BKV load in urine was significantly decreased 1 month after choreito administration. No adverse effects related to choreito administration were observed. Choreito may be a safe and considerably promising therapy for the hemostasis of BKV-HC after HSCT.

Juvenile myelomonocytic leukemia (JMML), a rare and aggressive myelodysplastic/myeloproliferative neoplasm that occurs in infants and during early childhood, is characterized by excessive myelomonocytic cell proliferation. More than 80% of patients harbor germ line and somatic mutations in RAS pathway genes (eg, PTPN11, NF1, NRAS, KRAS, and CBL), and previous studies have identified several biomarkers associated with poor prognosis. However, the molecular pathogenesis of 10% to 20% of patients and the relationships among these biomarkers have not been well defined. To address these issues, we performed an integrated molecular analysis of samples from 150 JMML patients. RNA-sequencing identified ALK/ROS1 tyrosine kinase fusions (DCTN1-ALK, RANBP2-ALK, and TBL1XR1-ROS1) in 3 of 16 patients (18%) who lacked canonical RAS pathway mutations. Crizotinib, an ALK/ROS1 inhibitor, markedly suppressed ALK/ROS1 fusion-positive JMML cell proliferation in vitro. Therefore, we administered crizotinib to a chemotherapy-resistant patient with the RANBP2-ALK fusion who subsequently achieved complete molecular remission. In addition, crizotinib also suppressed proliferation of JMML cells with canonical RAS pathway mutations. Genome-wide methylation analysis identified a hypermethylation profile resembling that of acute myeloid leukemia (AML), which correlated significantly with genetic markers with poor outcomes such as PTPN11/NF1 gene mutations, 2 or more genetic mutations, an AML-type expression profile, and LIN28B expression. In summary, we identified recurrent activated ALK/ROS1 fusions in JMML patients without canonical RAS pathway gene mutations and revealed the relationships among biomarkers for JMML. Crizotinib is a promising candidate drug for the treatment of JMML, particularly in patients with ALK/ROS1 fusions.

Acute immune thrombocytopenia (ITP) is a common benign bleeding disorder of variable etiology characterized by isolated thrombocytopenia. Intravenous immunoglobulin (IVIG) treatment is generally given as an initial treatment to pediatric patients with ITP, but markers predictive of the response to IVIG remain poorly defined. We retrospectively evaluated whether clinical and laboratory findings before treatment could predict response to IVIG and progression to chronic ITP in Japanese children with ITP. Between April 1997 and December 2011, a total of 49 children with newly diagnosed ITP were initially treated with IVIG. Their medical records were retrospectively reviewed. In multivariate analyses, lower white blood cell (WBC) count was the only unfavorable factor for response to IVIG and progression to chronic ITP. Patients with WBC count7.0 × 10(9)/L had a lower probability of thrombocytopenia-free survival (41 vs. 77 %, P = 0.003) and a higher rate of progression to chronic ITP (29 vs. 6 %, P = 0.040) than those with WBC count ≥7.0 × 10(9)/L. These results suggest that ITP with lower WBC count may represent a distinct subgroup requiring initial treatment other than IVIG.

Background In the treatment of bifurcation lesions, routine stenting of both branches has thus far failed to demonstrate a clear clinical advantage over a provisional one-stent strategy. On the other hand, large scale data evaluating different stent types for clinical outcomes after one-stent treatment with final kissing inflation (FKI) of bifurcation lesions is also limited. This prospective study evaluated the clinical and angiographic outcomes of paclitaxel-eluting stents (PES) vs. sirolimus-eluting stents (SES) in single crossover main branch stenting followed by FKI in patients with bifurcation lesions. Methods We randomized 800 patients with single bifurcation lesions to PES (n=400) and SES (n=400) groups. Results Crossover rates to the two-stent strategy were low in both groups (PES 1.5%, SES 2.8%; p=0.23). At 1year, there was no significant difference in the primary endpoint of this study, target lesion revascularization rate (PES 3.8%, SES 3.2%, hazard ratio 0.83; 95% confidence interval 0.39 to 1.76; p=0.62). Stent thrombosis occurred in only 1 case in the SES group after 282days. At 9months, a total of 593 patients underwent quantitative coronary measurement. The main branch restenosis rate in the PES group was significantly higher than that of the SES group (PES 12.2%, SES 5.5%; p=0.004), however both groups exhibited similar high side branch restenosis rates (PES 17.2%, SES 19.3%; p=0.6). Conclusions In patients with bifurcation lesions, a single stent strategy using PES and SES with FKI indicated similar 1year clinical outcomes and safety profiles.

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

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

Purpose Acute lymphoblastic leukemia (ALL) makes up a significant proportion of all pediatric cancers, and relapsed ALL is a leading cause of cancer-associated deaths in children. Identification of risk factors and druggable molecular targets in ALL can lead to a better stratification of treatments and subsequent improvement in prognosis. Patients and Methods We enrolled 59 children with relapsed or primary refractory ALL who were treated in our institutions. We primarily performed RNA sequencing (RNA-seq) using patients’ leukemic cells to comprehensively detect gene fusions and analyze gene expression profiles. On the basis of results obtained by RNA-seq, we performed genetic validation, functional analysis, and in vitro drug sensitivity testing using patients’ samples and an exogenous expression model. Results We identified a total of 26 gene fusions in 22 patients by RNA-seq. Among these, 19 were nonrandom gene fusions already described in ALL, and four of the remaining seven involved identical combination of MEF2D and BCL9. All MEF2D-BCL9–positive patients had B-cell precursor immunophenotype and were characterized as being older in age, being resistant to chemotherapy, having very early relapse, and having leukemic blasts that mimic morphologically mature B-cell leukemia with markedly high expression of HDAC9. Exogenous expression of MEF2D-BCL9 in a B-cell precursor ALL cell line promoted cell growth, increased HDAC9 expression, and induced resistance to dexamethasone. Using a primary culture of leukemic blasts from a patient, we identified several molecular targeted drugs that conferred inhibitory effects in vitro. Conclusion A novel MEF2D-BCL9 fusion we identified characterizes a novel subset of pediatric ALL, predicts poor prognosis, and may be a candidate for novel molecular targeting.

Summary We assessed the clinical utility of next-generation sequencing (NGS)-based monitoring of minimal residual disease (MRD) in a uniformly treated cohort of 79 patients with paediatric B-cell acute lymphoblastic leukaemia. Bone marrow samples were collected at the time of diagnosis, days 33 and 80, pre- (4–5 months) and post- (24 months) maintenance therapy time points, and at relapse. We identified leukaemia-specific CDR3 sequences in 72 of 79 patients (91%) and detected MRD in 59 of 232 samples. Although MRD was detected in 28 of 55 samples (51%) on day 33, the frequencies of MRD detection decreased to 25% (16/65) at day 80, 19% (11/58) at 4–5 months and 7·4% (4/54) at 24 months. In a univariate analysis, positive MRD results on day 80 [relative risk (RR) 95% confidence interval (CI) = 7·438 (2·561–21·6), P

Acute myeloid leukemia with abnormal bone marrow eosinophilia (AML-M4Eo) is often reported in core binding factor (CBF) leukemia, with translocations such as inv(16)(p13q22), t(16;16)(p13;q22) or t(8;21)(q22;q22); however, it is rarely reported with t(16;21)(q24;q22), which produces the RUNX1-CBFA2T3 (AML1-MTG16) chimera. The similarity between this chimera and RUNX1-RUNXT1 (AML1-MTG8) by t(8;21)(q22;q22) remains controversial. Adult leukemia with t(16;21)(q24;q22) was primarily therapy related, and shows poor prognosis; however, pediatric AML with this translocation was quite rare and tended to be de novo AML. We present here a 4-year-old boy with de novo AML-M4Eo and t(16;21)(q24;q22). He received chemotherapy and survived for more than 70 months without transplantation. We speculated that pediatric AML with t(16;21)(q24;q22) showed favorable prognosis, as with t(8;21)(q22;q22).

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

In SCT, death from transplant-related complications is the major obstacle hindering improvement of transplant outcomes, and proper supportive care is essential to reduce TRM. The transplant outcomes of 210 pediatric patients with malignant and non-malignant disorders who consecutively underwent SCT in our institution from 2000 to 2013 were analyzed. The transplant years were divided into three periods: A (2000-2004), B (2005-2008), and C (2009-2013), and an improvement in 5-year OS and a decrease in 5-year TRM were observed over these time periods; that is, OS was 61.5%, 60.3%, and 79.5% (P = .062), and TRM was 19.9%, 7.9%, and 0.0% (P

Though N-acetylcysteine (NAC),an antioxidant,has been used to prevent radio-contrast-induced nephropathy (RCIN),the effectiveness of using it remains unclear as the results of studies regarding its protective effect have been inconsistent.Since oral solutions of NAC have an unpleasant smell and taste,we previously developed a jelly preparation of NAC and in the present study,conducted a questionnaire survey to evaluate its user friendliness.The results of the survey indicated that the jelly preparation was effective in masking the unpleasant smell and taste.We also retrospectively examined the effectiveness of NAC in protecting against RCIN.Sixteen percent of patients in our control group (n=81,no NAC) developed RCIN,whereas none of the patients in the NAC-treated group (n=67)developed it.RCIN was defined as a greater than 25% increase in serum creatinine level occurring within 48 hours of exposure to a contrast medium.The results of this study showed that NAC has a protective effect against RCIN even in patients with a high risk of renal dysfunction,including those with diabetes or hypertension as well as those in whom high osmolarity contrast media are used.

We analyzed the correlation between rabbit ATG (rATG) serum levels and clinical outcomes in 37 children who received rATG at a total dose of 10 or 15 mg/kg during HSCT conditioning from an alternative donor. Fourteen patients had advanced malignant diseases, 13 had severe AA, and 10 had inherited disorders. Complete engraftment was achieved in all patients, and no rejection occurred. The cumulative incidence of grades II-IV acute GVHD and extensive chronic GVHD was 27% (95% CI, 12.5-39.6%) and 8.1% (95% CI, 0-23.1%), respectively. Multivariate analysis identified lower rATG levels at week 4 as an independent risk factor in the development of grades II-IV acute GVHD (p = 0.037). Serious infections were not observed in any patient following HSCT. No correlation was found between EBV reactivation and rATG levels at week 2 and week 4 after HSCT. Furthermore, no correlation was found between relapse and rATG levels two and four wk post-transplantation. The probability of five-yr OS among patients was 70.3% (95% CI, 59.8-79.2%). Our results suggest that targeted rATG administration may protect patients from severe acute GVHD without increasing the risk of EBV reactivation or relapse.

GATA2 , a member of the GATA transcription factor family, plays a critical role in hematopoiesis,[1][1] vascular[2][2] and neural development. Mutations in the exons and intron 5 of this gene have been identified as the cause of several hematologic disorders.[3][3] GATA2 -related disorders include

Predicting the response to immunosuppressive therapy could provide useful information to help the clinician define treatment strategies for patients with aplastic anemia. In our current study, we evaluated the relationship between telomere length of lymphocytes at diagnosis and the response to immunosuppressive therapy in 64 children with aplastic anemia, using flow fluorescence in situ hybridization. Median age of patients was ten years (range 1.5-16.2 years). Severity of the disease was classified as very severe in 23, severe in 21, and moderate in 20 patients. All patients were enrolled in multicenter studies using antithymocyte globulin and cyclosporine. The response rate to immunosuppressive therapy at six months was 52% (33 of 64). The probability of 5-year failure-free survival and overall survival were 56% (95% confidence interval (CI): 41-69%) and 97% (95%CI: 87-99%), respectively. Median telomere length in responders was -0.4 standard deviation (SD) (-2.7 to +3.0 SD) and -1.5 SD (-4.0 to +1.6 (SD)) in non-responders (P

Introduction Paraneoplastic pemphigus (PNP), an autoimmune disorder that can arise from malignancies, is fatal when complicated with bronchiolitis obliterans (BO), similar to that in patients receiving hematopoietic stem cell transplantation (HSCT). Autoantibodies to the desmosome proteins envoplakin and periplakin of epithelial cell adhesion molecules are essential for diagnosing PNP. BO after HSCT is an unfavorable complication that develops in association with chronic graft-versus-host disease (cGVHD). The effectiveness of rituximab on BO has been reported, which suggests that BO after HSCT is associated with autoimmunity similar to PNP. Here we analyzed anti-envoplakin and anti-periplakin antibodies that are associated with PNP in patients with and without BO complications who developed cGVHD after HSCT. Patients and Methods We analyzed anti-envoplakin and anti-periplakin antibodies in 21 patients (11 males and 10 females) with (n = 10) or without (n = 11) BO complications who developed cGVHD following HSCT between 1988 and 2015 at our institution. The median age at the time of HSCT in patients with and without BO was 10.8 (range, 1-21) and 7.5 (range, 1-14) years, respectively. The median duration from HSCT to BO onset was 261.6 (range, 41-825) days. We analyzed anti-envoplakin and anti-periplakin antibodies in cryopreserved sera collected before and after BO or cGVHD onset using immunoprecipitation (IPP) and enzyme-linked immunosorbent assay (ELISA) for detecting both autoantibodies. Longitudinal sera were obtained from a patient with cGVHD. Fifty-eight serum samples were collected from 21 patients. Biotinylated recombinant periplakin and envoplakin were produced from cDNAs using the transcription and translation (TnT) T7 Quick Coupled Transcription/Translation System (Promega) with rabbit reticulocyte lysates. IPP and ELISA were performed using in vitro TnT products as previously reported (Muro Y, et al. Rheumatology 2012;51:1508-13). Results On SDS-polyacrylamide gel electrophoresis, biotinylated recombinant periplakin and envoplakin showed protein bands with predicted size of 190 kDa and 210 kDa, respectively. The serum samples from the PNP patient and normal control serum were examined in an ELISA titration study. These titration curves showed the possibility of quantitatively measuring these autoantibodies. Both anti-envoplakin and anti-periplakin antibodies were positive in two of 10 patients with BO at BO onset but negative in all 11 patients without BO during cGVHD. In one of the two patients with plakin family autoantibodies, titers of anti-periplakin and anti-envoplakin antibodies gradually decreased after administering rituximab five times and repeating plasmapheresis seven times and subsequently decreased to below cut-off level. Although oxygenation substantially decreased consistent with the clearance of autoantibodies, the patient died of invasive pulmonary aspergillosis during steroid tapering. In the other patient, plakin family autoantibodies in the sera became negative after administering rituximab nine times. The patient is alive, and the spirometry findings were normal 6 years after the clearance of both autoantibodies. Conclusions Our findings indicate that plakin family autoantibodies may participate in BO onset in some patients receiving HSCT. The detection of these autoantibodies in patients with BO may be a good biomarker of cGVHD, providing a rationale and target for repeated rituximab therapy. Disclosures Kojima: SANOFI: Honoraria, Research Funding.

Introduction: Juvenile myelomonocytic leukemia (JMML) is a rare myeloproliferative neoplasm (MPN) that occurs during childhood and has a poor prognosis. Somatic or germline mutations in canonical RAS pathway genes, i.e., PTPN11, NF1, NRAS, KRAS, and CBL, are reported be detected in approximately 85% patients. Hematopoietic stem cell transplantation (HSCT) is the only curative therapy for JMML. Although spontaneous remission is occasionally observed in others with supportive therapy, some patients show aggressive disease progression despite HSCT. Recent studies have identified several additional genetic events in an array of genes, including SETBP1 and JAK3, but the relationship between genetic alterations and clinical outcomes remains unclear. Patients and Methods: A total of 131 patients (88 boys, 43 girls) with JMML were enrolled in the study. The median age was 15 months (range, 1-160 months). Eighty-two of 131 patients underwent HSCT, and 36 patients died (disease related, n = 27, transplantation-related complications, n = 16, infection, n = 5, unknown, n = 3). We performed comprehensive genetic analyses of the 131 JMML patients using whole-exome sequencing (n = 68, 52%) or targeted deep sequencing (n = 92, 70%), and assessed the impact of genetic alterations on clinical outcomes in 119 patients, excluding 12 patients with Noonan syndrome-related myeloproliferative disorder (NS/MPD). Results: We identified canonical RAS pathway gene mutations in 115 of 131 patients (88%). Although most RAS pathway mutations were mutually exclusive, coexisting secondary RAS pathway mutations were found in nine patients (8%). In addition, 28 patients harbored secondary genetic alterations in other genes, including SETBP1 (n = 10), JAK3 (n = 12), ASXL1 (n = 6), SH3BP1 (n = 1), RRAS2 (n = 2), and SOS1 (n = 3). In total, 34 of 131 patients harbored secondary genetic mutations. In univariate analysis, patients with secondary genetic mutations showed poorer survival rates than patients without these mutations [5-year transplantation-free survival (TFS) (95% CI) = 8.8% (2.3%-21.1%) vs. 24.1% (15.2%-34.1%), p = 0.007; 5-year overall survival (OS) (95% CI) = 49.6% (32.0%-65.0%) vs. 62.3% (50.8%-71.8%), p = 0.135]. On the basis of the dominant canonical RAS pathway mutations classification, patients with PTPN11 and NF1 mutations were significantly associated with the presence of secondary genetic mutations compared to patients with other RAS pathway gene mutations (PTPN11 (20 of 43, 47%), NF1 (5 of 7, 71%), NRAS (2 of 18, 11%), KRAS (4 of 20, 20%), CBL (1 of 17, 6%), p < 0.001). Consistent with previous reports, patients with PTPN11 and NF1 mutations had inferior survival rates than other JMML patients [5-year TFS (95% CI) = 0% vs. 32.7% (21.5%-44.3%), p < 0.001; 5-year OS (95% CI) = 45.3% (31.1%-58.5%) vs. 68.1% (55.2%-78.0%), p = 0.006]. Multivariate survival analysis identified the RAS pathway mutations (i.e., patients with PTPN11 and NF1 mutations vs. others) [TFS: HR (95% CI) = 3.732 (2.382-5.847), p < 0.001; OS: HR (95% CI) = 1.983 (1.117-3.521), p < 0.019] and low platelet count ( Discussion: Consistent with previous studies, secondary genetic mutations were associated with inferior survival rates, but high correlations were observed in JMML patientswith PTPN11 and NF1 mutations. Our results suggest that comprehensive genetic mutational profiling is essential to estimate prognosis and to stratify JMML patients who require HSCT and/or novel treatment modalities. Disclosures Ogawa: Sumitomo Dainippon Pharma: Research Funding; Takeda Pharmaceuticals: Consultancy, Research Funding; Kan research institute: Consultancy, Research Funding. Kojima:SANOFI: Honoraria, Research Funding.

Introduction: Paroxysmal nocturnal hemoglobinuria (PNH) is a nonmalignant clonal disease of hematopoietic stem cells resulting from a somatic mutation in the PIGA gene. PNH frequently manifests in association with aplastic anemia (AA), in which PIGA mutations are believed to enable escape from the immune-mediated destruction by pathogenic T cells. Recent studies using next-generation sequencing have revealed that frequent somatic PIGA mutationsin AA patients are associated with a better response to IST and prognosis (Yoshizato et al N Engl J Med. 2015; 373: 35-47). However, clinical PNH is a progressive and life-threatening disease driven by chronic hemolysis that leads to thrombosis, renal impairment, poor quality of life, and death. Large studies in adults have reported that clinical PNH developed in 10%-25% of AA patients; however; the frequency of clinical PNH in children with AA has rarely been described. Here we aimed to elucidate the pathological link between PNH and AA in children. Methods: In total, 57 children (35 boys and 22 girls) diagnosed with acquired AA at our hospital between 1992 and 2010 were retrospectively studied. Patients who underwent hematopoietic stem cell transplantation as first-line treatment within 1 year after AA diagnosis and those with clinical PNH at AA diagnosis were excluded. Flow cytometry (FCM) was used to detect PNH CD13+/CD55−/CD59− granulocytes and PNH glycophorin A+/CD55−/CD59− red blood cells (RBCs). Clinical PNH was defined as the presence of intravascular hemolysis and ≥5% PNH granulocytes or PNH RBCs. Minor PNH clones were defined as those with >0.005% PNH granulocytes or >0.010% PNH RBCs. We performed targeted sequencing of bone marrow samples from patients with clinical PNH that were obtained at 2 time points: at AA diagnosis and after PNH development. The panel of 184 genes for targeted sequencing included most of the genes known to be mutated in inherited bone marrow failure syndromes and myeloid cancers, as well as PIGA. Results: The median patient age at AA diagnosis was 9.3 (1.2-17.8) years, and the median follow-up period was 123 (2-228) months. A total of 43 patients were screened for PNH clones by FCM after AA diagnosis, and 21 of these with minor PNH clones were identified. The median percentages of PNH granulocytes and PNH RBCs were 0.001% (0.000%-4.785%) and 0.000% (0.000%-3.829%), respectively. During follow-up, 5 patients developed clinical PNH after adolescence (15-22 years of age). The median time between AA diagnosis and PNH development was 4.9 (3.3-7.9) years. All clinical PNH patients were treated with IST for AA, and complete and partial response after 6 months were achieved in 1 and 4 patients, respectively. Gross hemoglobinuria was present in all clinical PNH patients, but thrombosis was not observed. The size of PNH clones varied greatly among patients: PNH granulocytes and PNH RBCs were 42.96% (10.04%-59.50%) and 48.87% (15.02%-90.80%), respectively. Oral cyclosporine A and intravenous eculizumab were administered to 3 and 1 patients, respectively; all patients showed sustained response as indicated by improvement in gross hemoglobinuria and normal blood counts after treatment. The remaining 1 patient underwent bone marrow transplantation from the HLA-identical mother and was alive without any complications. Overall, the 10-year probability of developing clinical PNH was 10.2% (95%CI, 3.6-20.7). Among 43 patients screened for PNH clones at AA diagnosis, the 10-year cumulative clinical PNH incidence was significantly higher in patients with minor PNH clones than in those without minor PNH clones at AA diagnosis [29% (95% CI, 10%-51%) vs. 0% (95% CI, 0%-0%); p = 0.015]. Among all clinical PNH patients, a total of 8 somatic PIGA mutations were detected (missense, 2; splice site, 2; and frameshift, 4). However, PIGA mutations were not detected at AA diagnosis even in patients who subsequently developed clinical PNH. Conclusion: In our cohort, the percentage of patients who eventually developed clinical PNH was comparable to that reported in adults in a previous study. Furthermore, the current study showed that the presence of minor PNH clones at AA diagnosis was a risk factor for the subsequent development of clinical PNH, although the clones were not detected by targeted sequencing. Thus, pediatric AA patients with PNH clones at AA diagnosis should undergo long-term periodic monitoring for potential clinical PNH development. Disclosures Kojima: SANOFI: Honoraria, Research Funding.

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

Renal dysfunction is a significant risk factor in the prognosis of patients with cardiovascular diseases. We sought to determine the relationship between estimated glomerular filtration rate (eGFR) values and in-hospital mortality in Japanese acute myocardial infarction (AMI) patients. A total of 2266 consecutive AMI patients admitted to 22 hospitals in Hokkaido were registered. The eGFR values were determined using the following equation: eGFR=194 × (serum creatinine)(-1.094) × (age)(-0.287) ( × 0.739 if female). Patients were classified into four groups according to their eGFR values: ≥60 (n=1304), 30-59 (n=810), 15-29 (n=87) and15 ml min(-1) per 1.73 m(2) (n=65). A total of 110 patients (4.9%) died during hospitalization. The in-hospital mortality rate was significantly higher in patients with reduced eGFR values at 2.3, 5.4, 24.1 and 23.1% for eGFR values of ≥60, 30-59, 15-29, and15 ml min(-1) per 1.73 m(2), respectively. The odds ratios for in-hospital all cause death were 8.26 (95% confidence interval (CI): 2.22-30.77) for eGFR15 ml min(-1) per 1.73 m(2) and 3.42 (95% CI: 1.01-11.61) for eGFR 15-29 ml min(-1) per 1.73 m(2) compared with eGFR ≥60 ml min(-1) per 1.73 m(2). Similarly, the odds ratios for in-hospital cardiac death were 8.43 (95% CI: 1.82-39.05) for eGFR15 ml min(-1) per 1.73 m(2) and 5.47 (95% CI: 1.51-19.80) for eGFR 15-29 ml min(-1) per 1.73 m(2). In conclusion, the eGFR of30 ml min(-1) per 1.73 m(2) was a significant and independent risk for in-hospital mortality in abroad cohort of Japanese patients with AMI.

Introduction: Bone marrow-derived mesenchymal stromal cells (MSCs) exhibit in vitro immunomodulatory properties and have been effectively used to treat patients with acute GVHD following hematopoietic stem cell transplantation (HSCT). Expansion of MSCs involves the use of fetal bovine serum (FBS), although regulatory guidelines recommend that alternatives be used. Therefore, expansion of MSCs where FBS has been replaced by platelet lysates (PL) has been reported. Previous phase I studies of PL expanded third party, bone marrow derived MSCs have been reported showing no acute toxicity and 66 to 71% overall response rate. Although a uniform mechanism has not yet discovered, the available data have revealed immunomodulatory effects of MSCs therapy on T lymphocytes, B lymphocytes, NK cells, dendritic cells and macrophages. Therefore, we planned comprehensive evaluation of cytokines in patients who received PL expanded MSC therapy for steroid refractory acute GVHD. Materials and Methods: We conducted the phase 1 clinical trial of PL expanded MSC therapy for steroid resistant acute GVHD in children and young adults. Steroid resistance was defined as lack of clinical improvement after 7days treatment of methylprednisolone (2mg/kg/day) or GVHD progression within 3 days from steroid onset. MSCs were harvested frombone marrow donors and were expanded in 5% PL-containing medium. MSCs product had to satisfy all the release criteria including absence of bacteria, fungi, mycoplasma, endotoxin level < 5 EU/kg, > 70% viability, > 70% positivity for CD44, CD73 and CD105, and < 10% contamination by CD14, CD34, and CD45 hematopoietic cells. MSCs were injected intravenously immediately after thawing. Each MSC infusions aimed at reaching 1-2 x 10(6) cells/kg recipient body weight. Further MSC administrations could be provided with one week interval. Serum samples were collected before steroid treatment, before MSCs therapy, 1, 7, 14, 21, 28 days after MSCs therapy. A panel of 64 different cytokines was measured using Milliplex map Human Cytokine/Chemokine Magnetic Bead Panel (Millipore, Billerica, MA) to quantify the serum cytokine levels. The assay was performed according to the manufacturer's instructions. Results: Four patients (aged 2, 5, 15, 25 years) received intravenous (i.v.) MSCs for grade III-IV acute GVHD (liver: two cases, gut: two cases) on two occasions following HLA haploidentical HSCT or unrelated HLA matched SCT. The median dose of infusions was 1.2 x 10(6)/kg (range: 0.7-2.7 x 10(6)/kg). No acute side effects after infusions were observed. Clinical response was recognized within 7days and complete response was obtained in all four patients within 3 weeks from the administration of MSCs. Relapse of GVHD was not observed. Reactivation of cytomegalovirus (n = 3), Epstein-Barr virus (n = 1), adenovirus (n = 1), BK virus (n = 1), and fungal infection (n = 1) were observed in the four patients following the administration of MSCs. At a median follow-up of 21 months (range: 10-38 months), three of the four patients survived although one patient died of relapse of leukemia. The serum concentrations of the interleukins (IL)-6, interferon (IFN)g and Flt-3L were significantly elevated in all four patients before steroid therapy. Although Flt-3L level was decreased after steroid therapy in all the patients, IL-6 and IFNg were kept in high in two patients with liver GVHD grade 4. Serum level of IL-6 and IFNg were significantly decreased on day7 and day14 after MSCs therapy in both patients concomitant with 52.6-54.1% and 81.7-86.5% reduction of total bilirubin level on day7 and day14 respectively. Conclusion: This study supports the safety and efficacy of PL-expanded MSCs in the treatment of steroid-resistant GVHD in children and young adults. Reduction of inflammatory cytokines such as IL-6 and IFNg on day7 after MSCs infusion and observation of clinical response within 7days suggested the immunomodulatory effects of MSCs therapy on activated T lymphocytes as therapeutic mechanism of MSCs for acute GVHD rather than differentiation potential and regenerative effects of MSCs on damaged tissues. Disclosures No relevant conflicts of interest to declare.

Introduction Pancytopenia with a severe decrease in bone marrow (BM) cellularity in children may be caused by a broad variety of underlying disorders. The appropriate classification of bone marrow failure syndromes in children is challenging, particularly with respect to the histological distinction between aplastic anemia (AA), refractory cytopenia of childhood (RCC), and refractory cytopenia with multilineage dysplasia (RCMD). Inherited bone marrow failure syndromes (IBMFS) further defy accurate diagnosis. Clonal hematopoiesis in AA is indicated by the presence of paroxysmal nocturnal hemoglobinuria (PNH) cells and by the identification of uniparental disomies involving chromosome 6p. In addition, "clonal transformation," as defined by the development of myelodysplastic syndromes (MDS) or acute myelogenous leukemia has been noted in about 15% of AA patients. In adult patients with AA, somatic mutations were frequently detected in myeloid malignancy-related genes such as DNMT3A, BCOR, and ASXL1. We aimed to characterize the genetic background of childhood AA/RCC/RCMD. Patients and Methods We studied 168 patients with idiopathic AA/RCC/RCMD in children. Diagnosis with AA, RCC, and RCMD was made on the basis of the 2008 World Health Organization classification criteria. Blood, bone marrow, and buccal samples were obtained from the patients after written informed consent was received according to protocols approved by the ethics committee of Nagoya University Graduate School of Medicine. Target sequencing (n = 168) was performed for 88 IBMFS-associated genes and 96 myeloid malignancy-related genes. Furthermore, whole-exome sequencing (WES, n = 25) was performed with matched tumor/normal samples. The mean depth for targeted sequencing was 451x, and the mean depth for WES was 103x. Somatic mutations were detected with the use of a frequency threshold of 0.07 (WES) or 0.02 (targeted sequencing) for variant allele frequency and were individually validated with the use of deep sequencing of polymerase-chain-reaction-amplified targets. Results Only one germline mutation that was diagnostic of IBMFS was detected in our cohort (0.6%). It was a RTEL1 mutation, which supported the diagnosis of dyskeratosis congenita. Telomere length of the patient with a RTEL1 mutation was shorter compared with that of age-matched healthy individuals (−3.2 Standard Deviation). WES, performed in 25 patients, detected only three somatic mutations, all of which affected BCOR. In target sequencing, 20 somatic mutations were detected in 19 patients (11.3%). BCOR (n = 9) and PIGA (n = 4) were recurrently mutated. The mutational frequency of DNMT3A and ASXL1 was very low (0.6%) in our cohort and was clearly different from that of an adult cohort. The majority of somatic mutations carried low variant allele frequency. In case of BCOR mutations, the variant allele frequency tended to be low, suggesting subclonal composition. In case of U2AF1 mutations, the variant allele frequency tended to be high, which suggests that the U2AF1 -mutated clone was dominant in the bone marrow. The difference in the frequency of somatic mutations in AA, RCC, and RCMD was not statistically significant (p = 0.49). However, with regard to the mutated genes, two patients with RCMD carried U2AF1 plus SETBP1 and TP53 mutations, respectively, which are well-known predictors of poor prognosis in adult MDS. The patient who carried U2AF1 plus SETBP1 developed MDS later and underwent bone marrow transplantation. Of the 19 patients with mutated genes, 15 patients were treated with immunosuppressive therapy (IST). The response rate to IST at 6 months was 60% in the patients with somatic mutations, which was equivalent to those without mutations. Conclusions In our cohort of children who were clinically diagnosed with AA/RCC/RCMD, the frequency of cryptic IBMFS was considered low. Furthermore, the frequency of detectable somatic mutations in childhood AA was low compared with that in adult AA. No novel mutational target was identified with WES. Idiopathic bone marrow failure syndromes in children were characterized by a paucity of gene mutations irrespective of the histopathological classification. Mutations in adult MDS-related genes suggest molecular pathogenesis is different between RCMD and AA/RCC. In conclusion, our study clarified the yet unrevealed genetic background of idiopathic bone marrow failure syndromes in children. Disclosures No relevant conflicts of interest to declare.

We, retrospectively, examined the clinical course, decline in pulmonary function, and requirements for ventilatory assistance in 54 patients with Duchenne-type muscular dystrophy (DMD) who were followed in the muscle disease ward of the National Hospital in Kagoshima, Japan, over the past 20 years. The percentage of the predicted vital capacity (%VC) declined in relation to age and stage of disease. Most patients required assisted ventilation when the %VC fell below 10%. Twenty patients were treated with a negative pressure chest respirator. Six of these died at the mean age of 23.2 years after being on the respirator for a mean period of 18 months. Fourteen patients are surviving at a mean age of 23.5 years after being on the respirator for a mean period of 39 months.

Introduction: Acquired aplastic anemia (AA) is an immune mediated disease characterized by severe quantitative defects in stem cell number resulting in a hypocellular marrow and peripheral blood cytopenias. Immunosuppressive therapy (IST) using anti-thymocyte globulin (ATG) and cyclosporine A (CyA) is the standard therapy for patients with AA who lack a human leukocyte antigen (HLA)-matched sibling donor. Previous studies identified minor paroxysmal nocturnal hemoglobinuria (PNH) clones and short telomere length (TL) as predictive markers of the response to IST. However, the likelihood ratio of these markers was insufficient to influence clinical decisions. Here we assessed whether the combination of these markers could more accurately predict the response to IST. Methods: Between July 2001 and November 2013, 116 patients (65 boys and 51 girls) diagnosed with AA were examined to identify a minor population of PNH-type cells and TL of peripheral blood lymphocytes. Fifty-three patients received horse ATG (Lymphoglobulin, 15mg/kg/day for 5 days) and 63 received rabbit ATG (Thymoglobulin, 2.5−3.75 mg/kg/day for 5 days). CyA (6mg/kg/day) was started on day 1 and continued to at least day 180. The dose of CyA was adjusted to maintain trough levels between 100 and 200 ng/ml. Written informed consent was obtained from all patients’ parents. The ethics committee of each participating hospital approved the study. We used a flow cytometric assay to detect PNH-type granulocytes and red blood cells (RBCs). Presence of >0.007% CD13+ CD55− CD59− granulocytes and/or >0.009% glycophorin A+ CD55− CD59−RBCs was defined as PNH positive (PNH+), based on the results from healthy individuals. The average relative TL of peripheral lymphocytes was measured by flow-fluorescence in situ hybridization (flow-FISH) using a Telomere PNA Kit (Dako Cytomation). Based on our previous study, we defined −1.0 SD of age-adjusted controls as the cut-off value. Results: The median age at IST was 9.8 years (0.9−16.0). Disease severity of patients was assessed as moderate in 39, severe in 37, and very severe in 40, respectively. The causes of AA were idiopathic in 104 patients and hepatitis-associated in 12 patients. The median follow-up period from the time of IST was 36 months (range 1−134). Thirty-nine patients (34%) carried a minor PNH clone at diagnosis. Compared with healthy individuals, their median of TL was −1.08 SD (−4.01 to +3.01 SD). Overall, 60 of 116 patients (51.7%) responded to IST at 6 months after administration of ATG. In univariate analysis, the response rate at 6 months was higher in PNH+ patients than in PNH- patients (74.4% vs. 40.3%, respectively, p = 0.001). Longer TLs (≥−1.0 SD of age-adjusted control) were also associated with a favorable response to IST at 6 months (73.2% vs. 31.7%, p Conclusion: Combination of the absence of a minor PNH clone and a short TL was an efficient predictor of poor response to IST. These patients had low chances to respond to IST, which challenges the current standard of treatment. Prospective clinical trials are required to confirm these findings. Disclosures No relevant conflicts of interest to declare.

Introduction: Congenital bone marrow failure syndromes (CBMFSs) are a heterogeneous class of diseases with overlapping phenotypes. Therefore, a precise and comprehensive genetic diagnostic system is strongly warranted to arrive at appropriate clinical decisions to avoid ineffective therapies and/or lethal complications of allogeneic hematopoietic stem cell transplantation. However, a large panel of newly identified causative genes of CBMFSs have been identified in recent years; therefore, it is virtually impossible to establish a routine genetic diagnostic test using conventional Sanger sequencing. Whole-exome sequencing (WES) is a promising solution for the diagnosis of inherited diseases because it tests virtually all genes simultaneously. For the introduction of WES into clinical practice, it is necessary to clarify whether this technique has superior diagnostic efficacy to conventional clinical genetic tests. Methods: We performed WES in 250 patients with CBMFSs lacking genetic diagnoses. Exome capture was performed using the SureSelect® Human All Exon V3–5 kit (Agilent Technologies, Santa Clara, CA, USA), which covers all known coding exons, followed by massively parallel sequencing using the HiSeq 2000 Sequencing System (Illumina, San Diego, CA, USA). Our established pipeline for WES (genomon: http://genomon.hgc.jp/exome/) detected >20,000 candidate variants per patient. Diagnoses were based on variants of 130 genes with pathogenicities confirmed by published studies. Results: Genetic diagnoses were possible in 68 patients (27%). The best efficacy was achieved in patients with Fanconi anemia [35/73, 48%; FANCG (n = 17), FANCA (n = 14), FANCB (n = 1), FANCF (n = 1), SLX4 (n = 1), and BRCA2 (n = 1)], although Sanger sequencing was not applied because of the large sizes of its causative genes. Encouraging results were obtained in patients with Diamond–Blackfan anemia [11/ 61, 18%; RPS26 (n = 3), RPS7 (n = 2), RPS19 (n = 2), RPL5 (n = 2), RPL35A (n = 1), and RPL11 (n = 1)] and dyskeratosis congenita [7/29, 24%; TERT (n = 3), TINF2 (n = 2), and DKC1 (n = 2)]. Five genetic diagnoses (7%) were inconsistent with clinical diagnoses, possibly because of overlapping disease phenotypes. Conclusion: Relative to conventional genetic testing, WES was found to be effective for the diagnoses of CBMFSs. Furthermore, the efficacy of WES will increase as our knowledge of gene mutations expands. In conclusion, the use of WES in clinical practice is warranted. Disclosures No relevant conflicts of interest to declare.

Recent studies suggest that aberrant methylation plays a fundamental role in the development of a variety of cancers, including myeloid malignancies. Juvenile myelomonocytic leukemia (JMML) is an aggressive myeloid neoplasm of early childhood that is characterized by both excessive proliferation of myelomonocytic cells and hypersensitivity to granulocyte-macrophage colony-stimulating factor. It is categorized as an overlap myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) according to the World Health Organization classification. We recently reported that somatic mutations in SETBP1 and JAK3 were identified in JMML patients and were associated with poor outcomes (Nat Genet 2013;45:937–41). The goal of this study was to clarify the clinical significance of aberrant DNA methylation in JMML. We studied 92 children (61 boys and 31 girls) who were diagnosed with JMML in institutions throughout Japan. A diagnosis of JMML was made based on internationally accepted criteria. We quantitatively evaluated the CpG methylation pattern in the promoter regions of 16 candidate genes (APC, BMP4, CALCA, CDH13, CDKN2A, CDKN2B, CHFR, DAPK, DMR-H19, ER, IGF2, MGMT, MLH1, RARB, RASSF1, TP73) from genomic DNA derived from bone marrow specimens at the time of diagnosis. This was accomplished by bisulfite conversion and the pryosequencing technique. We defined aberrant methylation as >3 standard deviations from the mean methylation level derived from 8 healthy individuals. The median age at diagnosis was 16 months (range, 0.3–160). By genetic analysis, PTPN11, NF1, NRAS, KRAS, and CBL mutations were found in 39 (42%), 7 (8%), 12 (13%), 13 (14%), and 11 (12%) patients, respectively. In addition, 16 patients had SETBP1 or JAK3 mutations. Karyotypic abnormalities were detected in 15 patients, including 8 with monosomy 7. The median monocyte count, percentage of hemoglobin F, and platelet count at the time of diagnosis were 4.6x109/L (range, 0.2–31.6), 21% (range, 0–68), and 61.0x109/L (range, 1.4–483), respectively. The median observation period was 18 months (range, 1–287). During observation, 56 of the 92 patients received allogeneic hematopoietic stem cell transplantation (HSCT), and 30 of 92 patients died. Outcomes were assessed according to transplantation-free survival (TFS), in which HSCT and death were censored, and overall survival (OS) by the Kaplan-Meier method. Aberrant methylation of BMP4, CALCA, CDKN2A, CDKN2B, DMR-H19 and RARB were detected, of which hypermethylation of BMP4, CALCA, CDKN2A, and RARB were associated with poor TFS according to univariate analyses (P The present study shows that aberrant methylation of four genes (BMP4, CALCA, CDKN2A, and RARB) is associated with poor outcomes in JMML patients. Patients with SETBP1/JAK3 mutations frequently show the hypermethylation of these genes. Further, allogeneic HSCT is associated with improved outcomes for patients with AMS = 1 and 2. Therefore, these results suggest that examination of the methylation pattern of these four genes may help guide clinical decisions for the management of patients with JMML. Disclosures: Makishima: AA & MDS international foundation: Research Funding; Scott Hamilton CARES grant: Research Funding. Maciejewski:NIH: Research Funding; Aplastic anemia&MDS International Foundation: Research Funding.

Introduction HLA haploidentical relatives could be useful alternative donor option for patients without HLA matched family donor who need relatively urgent stem cell transplantation. However, steroid refractory GVHD and virus infections were critical issues in this setting due to HLA mismatched barrier. Donor derived cellular therapies could be suitable options to improve the outcome of this strategy. Patients and methods Twenty three children (9 male, 14 female) underwent HLA haploidentical stem cell transplantation in Nagoya University hospital from 2004 to 2013. The median age was 8 years [range 1 – 15years] with 7 AML, 6 ALL, 5 aplastic anemia, 2 JMML, 1 CMML, 1 CAEBV and 1 LCH. All the patients received both bone marrow combined with G-CSF mobilized peripheral blood stem cells to increase the number of infused donor stem cells. Total 15mg /kg of rabbit antithymocyte globulin (ATG) were given as in vivo T cell depletion in preconditioning regimen. Taclolimus and short term MTX were used for GVHD prophylaxis. CMV and EBV specific cytotoxic T cells were tried to expand from donor peripheral blood mononuclear cells if the patient and the donor shared either HLA A2402 or A0201/A0206 as treatment options for drug resistant virus infections since 2008. Mesenchymal stem cells were also expanded from donor bone marrow for the option of treatment for steroid refractory GVHD since 2009. All the donors were one of parents of patient’s except for one brother. HLA disparity between patient and donor at HLA A, B, and DR loci were three loci in 12 patients and two loci were in other 11 patients. Results All the patients achieved engraftment with median 18 days [range 14 – 29 days]. Acute GVHD grade II or more were seen in nine patients. Six of them developed steroid refractory GVHD and received Infliximab. Four of them received Daclizumab as well. Among them, two patients developed uncontrolled grade IV GVHD (One patient developed diarrhea more than three litters with blood and another patient developed Grade IV liver GVHD) even after combination therapy of Infliximab and Daclizumab. Two infusions of donor bone marrow derived MSC were given in these two patients and GVHD were diminished. CMV reactivations were seen in 16 and 3 of them developed both GCV and Foscanet resistant CMV infection and donor derived CMV specific CTL infusions were effective to eradicate CMV-DNA in their blood without inducing GVHD. EBV reactivations were seen in 12 and empiric rituximab infusion was effective in 11. One patient developed CD20 negative EBV associated lymphoproliferative disorder and 5 course of donor derived EBV specific T cell infusions eradicate EBV-DNA in his blood and PET positive lymphadenopathy was diminished. BK virus cystitis were seen in four. Cause of death were 8 leukemia relapses, one adenovirus fluminant hepatitis on day 123, one CMV ventriculitis on day 378 and one sepsis on day 509. Conclusions Donor virus specific CTLs and mesenchymal stem cells were useful options for HLA haploidentical stem cell transplantation to reduce early transplantation related mortality. Disclosures: No relevant conflicts of interest to declare.

Introduction Pancytopenia accompanied by a severe decrease in bone marrow (BM) cellularity in children can be due to a broad variety of underlying disorders. Appropriate classification of bone marrow failure syndrome in children is challenging, particularly in relation to the morphological distinction between aplastic anemia (AA), refractory cytopenia of childhood (RCC), and refractory cytopenia with multilineage dysplasia (RCMD). The goal of this study was to characterize the molecular pathogenesis of these conditions by identifying the full spectrum of gene mutations in 29 patients with these disorders through the use of exome sequencing. Patient and Methods Diagnosis of AA, RCC, or RCMD was made on basis of the 2008 World Health Organization (WHO) classification criteria. AA patients exhibited no morphologically dysplastic changes in any of their hematopoietic cell lineages, while RCC patients had10% in one cell lineage. Patients classified as RCMD exhibited >10% of the dysplastic changes in two or more cell lineages. Blood and BM samples were obtained from 29 children (16 boys and 13 girls) with AA (n = 8), RCC (n = 11), or RCMD (n = 10). The median age at diagnosis was 11 years (range, 2–15 years). Exome capture from paired DNA (non-T cells/CD3+ lymphocyte) was performed using SureSelect® Human All Exon V3 (Agilent Technologies, Santa Clara, CA) covering 50 Mb of the coding exons, followed by massive parallel sequencing using HiSeq 2000 (Illumina, San Diego, CA) according to the manufacturer’s protocol. Candidate somatic mutations were detected through our pipeline for whole exome sequencing (genomon: http://genomon.hgc.jp/exome/index.html). All candidate somatic nucleotide changes were validated by Sanger sequencing. Results Exome sequencing pipeline identified a total of 193 non-synonymous somatic mutations or indels candidates among the 29 patients (range, 2–15 per patient). After validation by Sanger sequencing, one nonsense, 11 missense, and two frame-shift mutations were confirmed as non-silent somatic mutations. The average numbers of mutations per sample were not significantly different when comparing morphological diagnostic groups (0.50 in AA, 0.36 in RCC, 0.60 in RCMD). Of these validated genes, BCOR (n = 2) and CSK (n = 2) mutations were recurrent genetic events. BCOR is a frequent mutational target in myelodysplastic syndrome, whereas CSK somatic mutations were not reported in human cancers. BCOR mutations were found both in AA (c.472delA:p.S158fs; patient 13) and in RCMD (c.G3856T:p.E1286X; patient 39). Both patients with CSK mutations were classified as RCC (c.G994A:p.D332N; patient 23 and 27). When comparing the clinical outcomes of patients with somatic mutations (n = 7) versus those without somatic mutations (n = 22), response rate to immunosuppressive therapy at 6 months (50% vs. 50%), 5-year clonal evolution rate (95% confidential interval) [0% (0% - 0%) vs. 6% (0% - 26%)], and the 5-year overall survival rate (95% confidential interval) [100% (100% - 100%) vs. 95% (70% - 99%)] were not significantly different. Conclusion Whole exome sequencing analysis was used for gene mutational profiling of patients with idiopathic bone marrow failure syndromes; i.e., AA, RCC, and RCMD. Although BCOR and CSK somatic mutations were recurrently identified, idiopathic bone marrow failure syndromes in children are characterized by a paucity of gene mutations, irrespective of morphological diagnosis. These findings suggest that morphological diagnosis based on WHO classification system does not discriminate the mutational profile and pathogenesis of bone marrow failure in children. Disclosures: No relevant conflicts of interest to declare.

Immune thrombocytopenic purpura (ITP) is a common benign bleeding disorder characterized by isolated thrombocytopenia caused by the immune-mediated destruction of platelets. The 2004 Japanese Guidelines for Childhood ITP recommended intravenous immunoglobulin (IVIG) as first-line therapy for children with ITP, because this strategy results in more rapid increases in platelet counts when compared with oral steroid therapy. However, predictive markers of the response to IVIG have not been well defined. The present study therefore evaluated whether clinical and laboratory findings before treatment could predict the response to IVIG and progression to chronic ITP. We reviewed the clinical data of 49 newly diagnosed patients (< 18 years) with ITP who were given IVIG as initial treatment at Japanese Red Cross Nagoya First Hospital from 1997 to 2011, and evaluated the short-term response to IVIG as outcomes at 2 weeks after IVIG and the long-term response to IVIG as thrombocytopenia-free survival (TFS). TFS was defined as the probability of survival without treatment failure (death, relapse, disease progression requiring other therapeutic intervention, or progression to chronic ITP) after initial IVIG and was estimated by the Kaplan-Meier method. Short-term response to IVIG was observed in 40 patients (82%), and long-term treatment response, defined as 1-year TFS, was 65%. At 6 months after initial IVIG treatment, seven patients (14%) progressed to chronic ITP. In multivariate analysis, lower white blood cell (WBC) count at diagnosis was identified as the only independent risk factor for the short- or long-term response to IVIG (P=0.007 or P=0.043, respectively) and the progression to chronic ITP (P=0.034). Patients with WBC count In conclusion, this study showed that WBC count at onset of ITP is a strong predictor of short- and long-term treatment response to IVIG and the development of chronic ITP in pediatric patients with ITP. For patients with low WBC count, the addition of other agents, such as steroids, to IVIG at the time of initial diagnosis might improve the treatment outcomes. Disclosures: No relevant conflicts of interest to declare.