Children with Down syndrome (DS) with acute megakaryocytic leukemia (AMkL) have very high survival rates compared with non-DS AMkL patients. Somatic mutations identified in the X-linked transcription factor gene, GATA1, in essentially all DS AMkL cases result in the synthesis of a shorter (40 kDa) protein (GATA1s) with altered transactivation activity and may lead to altered expression of GATA1 target genes. Using the Affymetrix U133A microarray chip, we identified 551 differentially expressed genes between DS and non-DS AMkL samples. Transcripts for the bone marrow stromal-cell antigen 2 (BST2) gene, encoding a transmembrane glycoprotein potentially involved in interactions between leukemia cells and bone marrow stromal cells, were 7.3-fold higher (validated by real-time polymerase chain reaction) in the non-DS compared with the DS group. Additional studies confirmed GATA1 protein binding and transactivation of the BST2 promoter; however, stimulation of BST2 promoter activity by GATA1s was substantially reduced compared with the full-length GATA1. CMK sublines, transfected with the BST2 cDNA and incubated with HS-5 bone marrow stromal cells, exhibited up to 1.7-fold reduced cytosine arabinoside (ara-C)-induced apoptosis, compared with mock-transfected cells. Our results demonstrate that genes that account for differences in survival between DS and non-DS AMkL cases may be identified by microarray analysis and that differential gene expression may reflect relative transactivation capacities of the GATA1s and full-length GATA1 proteins.

We present a patient with haemophilia undergoing cardiac surgery treated with continuous infusion factor VIII.

Patients with Langerhans cell histiocytosis (LCH) may behave differently depending on what sites are involved and the response or lack of response to earlier therapies. Therapy for high‐risk patients or those with multiple reactivations continues to be challenging because of variable response rates and frequent toxicities. The goals of this study were to determine the long‐term disease free survival in children with high‐risk or multiply reactivated LCH treated with 2‐CDA, and the toxicity of low dose continuous infusion (CI). Ten children with multiple reactivations or high‐risk disease as defined by the Histiocyte Society were treated with CI 2‐CDA and were evaluable for response and toxicity assessment. The starting dose of 2‐CDA was 5 mg/M2/day for 3 days and escalated to 6.5 mg/M2/day for 3 days if tolerated. The maximum number of courses of 2‐CDA per patient was limited to six. Fifty‐two courses of 2‐CDA were administered without difficulty. After the patient demonstrated no acute toxicity with the first administration of 2‐CDA, the subsequent doses were given at home to all but one patient. All 10 patients had a clinical response, 9 documented by radiographic, or changes in physical exam or review of systems. Toxicity was limited to myelosuppression. Seven of the 10 patients required no additional therapy and remain disease free a median of 50 months from completing therapy. The three remaining patients are currently disease free after receiving other therapy. Further studies are needed to determine the role of 2‐CDA in this patient population. 2‐CDA can be given safely using home therapy, and may effective even in high‐risk patients. © 2004 Wiley‐Liss, Inc.

Fms-like tyrosine kinase 3 (FLT3) mutations are associated with unfavorable outcomes in children with acute myeloid leukemia (AML). We used DNA microarrays to identify gene expression profiles related to FLT3 status and outcome in childhood AML. Among 81 diagnostic specimens, 36 had FLT3 mutations (FLT3-MUs), 24 with internal tandem duplications (ITDs) and 12 with activating loop mutations (ALMs). In addition, 8 of 19 specimens from patients with relapses had FLT3-MUs. Predictive analysis of microarrays (PAM) identified genes that differentiated FLT3-ITD from FLT3-ALM and FLT3 wild-type (FLT3-WT) cases. Among the 42 specimens with FLT3-MUs, PAM identified 128 genes that correlated with clinical outcome. Event-free survival (EFS) in FLT3-MU patients with a favorable signature was 45% versus 5% for those with an unfavorable signature (P = .018). Among FLT3-MU specimens, high expression of the RUNX3 gene and low expression of the ATRX gene were associated with inferior outcome. The ratio of RUNX3 to ATRX expression was used to classify FLT3-MU cases into 3 EFS groups: 70%, 37%, and 0% for low, intermediate, and high ratios, respectively (P < .0001). Thus, gene expression profiling identified AML patients with divergent prognoses within the FLT3-MU group, and the RUNX3 to ATRX expression ratio should be a useful prognostic indicator in these patients.

Medical and Pediatric OncologyVolume 41, Issue 1 p. 77-78 Brief Report Long-term survival in osteosarcoma patients following retinoblastoma using doxorubicin, cisplatin, and methotrexate Kimo C. Stine MD, Corresponding Author Kimo C. Stine MD stinekimoc@uams.edu Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, ArkansasDepartment of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, 800 Marshall St., Little Rock, AR 72202.Search for more papers by this authorRobert L. Saylors MD, Robert L. Saylors MD Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, ArkansasSearch for more papers by this authorSuzanne Saccente MD, Suzanne Saccente MD Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, ArkansasSearch for more papers by this authorDavid L. Becton MD, David L. Becton MD Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, ArkansasSearch for more papers by this author Kimo C. Stine MD, Corresponding Author Kimo C. Stine MD stinekimoc@uams.edu Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, ArkansasDepartment of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, 800 Marshall St., Little Rock, AR 72202.Search for more papers by this authorRobert L. Saylors MD, Robert L. Saylors MD Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, ArkansasSearch for more papers by this authorSuzanne Saccente MD, Suzanne Saccente MD Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, ArkansasSearch for more papers by this authorDavid L. Becton MD, David L. Becton MD Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, ArkansasSearch for more papers by this author First published: 16 May 2003 https://doi.org/10.1002/mpo.10311Citations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume41, Issue1July 2003Pages 77-78 RelatedInformation

High frequency of the 844ins68 cystathionine-β-synthase gene variant in Down syndrome children with acute myeloid leukemia

The purpose of this study was to assess the effect of the multidrug resistance modulator cyclosporine (CsA) on the pharmacokinetics of etoposide and mitoxantrone in children with de novo acute myeloid leukemia (AML). Serial blood samples for pharmacokinetic studies were obtained in 38 children over a 24-h period following cytotoxin treatment with or without CsA on days 1 and 4. Drug concentrations were quantitated using validated HPLC methods, and pharmacokinetic parameters were determined using compartmental modeling with an iterative two-stage approach, implemented on ADAPT II software. Etoposide displayed a greater degree of interindividual variability in clearance and systemic exposure than mitoxantrone. With CsA treatment, etoposide and mitoxantrone mean clearance declined by 71% and 42%, respectively. These effects on clearance, in combination with the empiric 40% dose reduction for either cytotoxin, resulted in a 47% and 12% increases in the mean AUC for etoposide and mitoxantrone, respectively. There were no differences in the rates of stomatitis or infection between the two groups. CsA treatment resulted in an increased incidence of hyperbilrubinemia, which rapidly reversed upon conclusion of drug therapy. The variability observed in clearance, combined with the empiric 40% dose reduction of the cytotoxins, resulted in statistically similar systemic exposure and similar toxicity.

Arkansas Children's Hospital Research Institute, Univ. of Arkansas for Medical Sciences, Little Rock, AR

The purpose of this study was to determine if KRN5500, a spicamycin derivative with a unique acyl tail, would induce programmed cell death (PCD) of myeloid leukemia cell lines and cryopreserved leukemic blasts from newly diagnosed children with acute leukemia (AL). Cells were incubated with varying concentrations (0-5 ng/ml) of KRN5500 and the percent PCD determined using a modified in situ end labeling (ISEL) technique with Klenow fragment. The percent PCD was calculated using the formula: Percent PCD (% PCD)=[number of apoptotic cells/(viable cells+apoptotic cells)]x100. DMSO (0.30% w/v) was added to the cells in culture as the positive control for PCD; the negative control was media or albumin. KRN5500 increased the amount of PCD significantly in all five of the tested cell lines; U937 41+/-1.8%, KG1a 40+/-0.3%, HEL 14+/-2.2%, HL-60 41+/-0. 9%, K562 36+/-2% (mean PCD+/-SD). Patient blasts exposed to KRN5500 had an increase in PCD when exposed to 2 ng/ml of agent from 2 to 8 h; acute myeloid leukemia patients 7.5+/-0.5% at 2 h to 43.5+/-1.6% at 8 h, and acute lymphocytic leukemia patients rose from 12.4+/-3.8% at 2 h to 29.9+/-11.6% after 8 h (mean+/-SE). Overall the PCD for the patient samples was 3.7 versus 28+/-4% at 2 and 8 h, respectively. PCD was proportional to the dose of KRN5500 and incubation time. Further pre-clinical and clinical studies are required.

The high event-free survival rates of Down syndrome (DS) children with acute myeloid leukemia (AML) are due, in part, to increased in vitro sensitivity of DS myeloblasts to cytosine arabinoside (ara-C) and daunorubicin and the greater generation of ara-C triphosphate (ara-CTP) from ara-C compared with myeloblasts from non-DS patients (Taub et al, Blood 87:3395, 1996). This study further explores the molecular basis of chemotherapy sensitivity of DS AML patients by examining the expression of chromosome 21-localized genes in myeloblasts from newly diagnosed AML patients. Transcript levels of two chromosome 21-localized genes, cystathionine-beta-synthase (CBS) and superoxide dismutase (SOD), measured by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), were 12.0- and 3. 8-fold higher in DS compared with non-DS myeloblasts (P <.0001 and P <.0001, respectively). Conversely, there were no significant increases in transcripts for 2 other chromosome 21-localized genes, carbonyl reductase and the reduced folate carrier. CBS transcript levels correlated with both in vitro ara-C sensitivity measured by the 3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium-bro mid e (MTT) assay (P =.003) and the generation of (3)H-ara-C triphosphate (ara-CTP) after in vitro incubations with 5 micromol/L (3)H-ara-C (P =.0003). Transcripts of deoxycytidine kinase were 2.6-fold higher in DS compared with non-DS cells and may be a factor in the enhanced metabolism of ara-C in DS cells. There was no significant correlation of SOD transcripts with in vitro ara-C and daunorubicin sensitivities. Increased CBS transcripts could result in elevated CBS activity, which modulates ara-C metabolism by altering reduced folate pools, deoxycytidine triphosphate pools, S-adenosylmethionine levels, and/or methylation of the deoxycytidine kinase gene. The further identification of the molecular mechanisms of chemotherapy sensitivity of DS AML patients may lead to significant improvements in the treatment and cure of AML.

IL-2 augments the ability of natural killer (NK) cells to kill myeloid leukemia cells in vitro , and may have a role in the eradication of minimal residual disease (MRD) in AML patients. The ability to enhance lysis of AML cells without the toxicity of IL-2 would be a significant improvement in the use of biologics against AML. Recent interest in IL-12 suggested that this cytokine might meet these criteria. The aim of this study was to evaluate the ability of IL-12 to enhance the in vitro lysis of the non-lymphoid leukemia cell lines in a standard 51 Chromium release assay. Effector cells from normal volunteers were incubated with varying concentrations of IL-12 or IL-2 for 18–20 h, then the 51 Cr-labeled target cells from five different cell lines of AML origin were added for 4 h. Percent lysis was determined and plotted over four effector:target (E:T) ratios. Our results indicated that IL-12 was able to enhance lysis of all cell lines tested at ⩾5 units/ml. When IL-2 was added to the culture at a low dose along with IL-12, there appeared to be a synergistic effect. Although anti-gamma interferon was able to inhibit the cytolytic potential of effectors activated by IL-12, the lysis could not be completely blocked. Thus, it appears that IL-12 has the ability to stimulate NK lysis indirectly through the induction of gamma interferon as well as an alternate mechanism not related to gamma interferon. Thus, IL-12 may have a beneficial role in the treatment of non-lymphoid leukemia.

Myeloblasts from Doen syndrome children with acute myeloid leukemia have increased in vitro sensitivity to cytosine arabinoside and daunorubicine

Lupus anticoagulants (LAs) represent a diverse group of antibodies directed against phospholipids. Patients with LAs may be free of symptoms but can have thrombotic complications including stroke, placental infarction, and fetal loss. Rarely hemorrhagic symptoms have been reported. We describe six previously healthy children who were first seen with clinical bleeding and prolonged activated partial thromboplastin time. Laboratory evaluation revealed positive results on mixing studies and evidence of phospholipid dependence of the anticoagulant, suggesting LAs. Four of six patients had anticardiolipin antibodies, and all four who were tested had reduced factor II activity levels. In all patients, bleeding symptoms resolved spontaneously within 3 months, and laboratory findings returned to normal within 6 months. The hemorrhagic LA syndrome should be considered in previously healthy children with new-onset bleeding and prolonged activated partial thromboplastin time. This clinical entity probably represents a pathogenic mechanism distinct from thrombotic LA syndromes. (J Pediatr 1997;130:998-1000)

PURPOSE Patients with Ehlers-Danlos syndrome (EDS), especially types IV, VI, and VIII, are at increased risk of bleeding, and most do not have specific hemostatic deficiencies that would be amenable to replacement therapy. We have investigated the ability of DDAVP (desmopressin acetate) to control bleeding in EDS. PATIENTS AND METHODS Two children with EDS, types VIII and VI, presented with hemorrhagic symptoms and scheduled surgical procedures. Ivy bleeding times (BTs) were measured before and after intravenous (i.v.) DDAVP challenge, and i.v. DDAVP was used prophylactically for their procedures. Laboratory testing was performed to rule out other hemostatic disorders. RESULTS Both patients had prolonged BTs that corrected following i.v. DDAVP therapy; all other laboratory values were normal. Both patients had excellent clinical hemostasis with surgery, and one has continued to use intranasal DDAVP to control epistaxis and gingival bleeding. CONCLUSIONS The bleeding time in both patients was corrected with DDAVP, and the patients did not have any postoperative bleeding. DDAVP should be considered in other patients who have EDS with bleeding tendencies.

PURPOSE To present two patients as illustrations of the risk of developing secondary acute myelogenous leukemia (sAML) when theoretically safe doses of etoposide (VP-16) are used. PATIENTS AND METHODS Patient no. 1 was a 15-year-old white girl diagnosed with stage IIa Hodgkin's disease. She was treated with a combination of vincristine, doxorubicin, bleomycin, and VP-16 (2 g/m2 total) over 4 months, followed by 25.5 Gy of involved-field radiotherapy. Patient no. 2 was an 11-year-old white boy diagnosed with virus-associated hemophagocytic syndrome (VAHS). He was treated with VP-16 intravenously (IV) and orally (0.3 g and 2.8 g/m2, respectively). RESULTS Patient no. 1 developed AML 16 months from the diagnosis of Hodgkin's disease. Patient no. 2 developed AML 26 months from diagnosis. Both bone marrows were consistent with French-American-British (FAB) M4 disease. Both patients had abnormalities of the long arm of chromosome 11. CONCLUSION The use of low-dose or oral VP-16 can be associated with the development of sAML. Clinicians should be cautious in the use of VP-16 in low-risk diseases.

Annals of the New York Academy of SciencesVolume 795, Issue 1 p. 420-421 Apoptosis Induced by Interleukin-12 Measured by DNA Electrophoresis and in Situ End Labeling in Leukemia K. C. STINE, K. C. STINE Arkansas Children's Hospital Pediatric Hematology 800 Marshall Street Little Rock, Arkansas 72202Search for more papers by this authorB. A. WARREN, B. A. WARREN Arkansas Children's Hospital Pediatric Hematology 800 Marshall Street Little Rock, Arkansas 72202Search for more papers by this authorD. L. BECTON, D. L. BECTON Arkansas Children's Hospital Pediatric Hematology 800 Marshall Street Little Rock, Arkansas 72202Search for more papers by this author K. C. STINE, K. C. STINE Arkansas Children's Hospital Pediatric Hematology 800 Marshall Street Little Rock, Arkansas 72202Search for more papers by this authorB. A. WARREN, B. A. WARREN Arkansas Children's Hospital Pediatric Hematology 800 Marshall Street Little Rock, Arkansas 72202Search for more papers by this authorD. L. BECTON, D. L. BECTON Arkansas Children's Hospital Pediatric Hematology 800 Marshall Street Little Rock, Arkansas 72202Search for more papers by this author First published: October 1996 https://doi.org/10.1111/j.1749-6632.1996.tb52710.xCitations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume795, Issue1Interleukin 12: Cellular and Molecular Immunology of an Important Regulatory CytokineOctober 1996Pages 420-421 RelatedInformation