Prevalence of chronic hepatitis C virus infection among childhood cancer survivors in Stockholm, Sweden.

Childhood cancer survivors treated before 1992, when blood donor screening for hepatitis C virus (HCV) infection was introduced, are at risk of transfusion-transmitted HCV infection. A national HCV screening campaign targeting blood transfusion recipients was launched in Sweden in 2007-2010. The aims of this study were to, among adult childhood cancer survivors in Stockholm County, investigate the prevalence of HCV infection, the natural course of infection, treatment outcome and anti-HCV testing frequency before, during and after the screening campaign and finally to actively screen the untested ones.

Treatment-related mortality in relapsed childhood acute lymphoblastic leukemia.

Background: Treatment of relapsed childhood acute lymphoblastic leukemia (ALL) is particularly challenging due to the high treatment intensity needed to induce and sustain a second remission. To improve results, it is important to understand how treatment-related toxicity impacts survival.

Procedure: In this retrospective population-based study, we described the causes of death and estimated the risk for treatment-related mortality in patients with first relapse of childhood ALL in the Nordic Society of Paediatric Haematology and Oncology ALL-92 and ALL-2000 trials.

Expanded Adaptive NK Cells Effectively Kill Primary Acute Lymphoblastic Leukemia Cells.

Manipulation of human natural killer (NK) cell repertoires promises more effective strategies for NK cell-based cancer immunotherapy. A subset of highly differentiated NK cells, termed adaptive NK cells, expands naturally in response to human cytomegalovirus (HCMV) infection, carries unique repertoires of inhibitory killer cell immunoglobulin-like receptors (KIR), and displays strong cytotoxicity against tumor cells. Here, we established a robust and scalable protocol for generation and expansion of adaptive NK cells for cell therapy against pediatric acute lymphoblastic leukemia (ALL).

Parents' and Adolescents' Preferences for Intensified or Reduced Treatment in Randomized Lymphoblastic Leukemia Trials.

Background: When offered participation in clinical trials, families of children with cancer face a delicate balance between cure and toxicity. Since parents and children may perceive this balance differently, this paper explores whether adolescent patients have different enrollment patterns compared to younger children in trials with different toxicity profiles.

Procedure: Age-dependent participation rates in three consecutive, randomized childhood leukemia trials conducted by the Nordic Society of Paediatric Haematology and Oncology were evaluated.

Relapsed childhood acute lymphoblastic leukemia in the Nordic countries: prognostic factors, treatment and outcome.

Relapse is the main reason for treatment failure in childhood acute lymphoblastic leukemia. Despite improvements in the up-front therapy, survival after relapse is still relatively poor, especially for high-risk relapses. The aims of this study were to assess outcomes following acute lymphoblastic leukemia relapse after common initial Nordic Society of Paediatric Haematology and Oncology protocol treatment; to validate currently used risk stratifications, and identify additional prognostic factors for overall survival.

Detection of central nervous system involvement in childhood acute lymphoblastic leukemia by cytomorphology and flow cytometry of the cerebrospinal fluid.

Background: Therapy directed at the central nervous system (CNS) is an essential part of the treatment for childhood acute lymphoblastic leukemia (ALL). The current evaluation of CNS involvement based on cytomorphological examination of the cerebrospinal fluid (CSF) alone is not as sensitive with low cell counts as flow cytometric immunophenotyping (FCI) of the CSF. However, the importance of low CSF blasts counts at diagnosis is uncertain.

The mutational landscape in pediatric acute lymphoblastic leukemia deciphered by whole genome sequencing.

Genomic characterization of pediatric acute lymphoblastic leukemia (ALL) has identified distinct patterns of genes and pathways altered in patients with well-defined genetic aberrations. To extend the spectrum of known somatic variants in ALL, we performed whole genome and transcriptome sequencing of three B-cell precursor patients, of which one carried the t(12;21)ETV6-RUNX1 translocation and two lacked a known primary genetic aberration, and one T-ALL patient. We found that each patient had a unique genome, with a combination of well-known and previously undetected genomic aberrations.

Prognostic implications of mutations in NOTCH1 and FBXW7 in childhood T-ALL treated according to the NOPHO ALL-1992 and ALL-2000 protocols.

Background: In children, T-cell acute lymphoblastic leukemia (T-ALL) has inferior prognosis compared with B-cell precursor ALL. In order to improve survival, individualized treatment strategies and thus risk stratification algorithms are warranted, ideally already at the time of diagnosis.

Procedure: We analyzed the frequency and prognostic implication of mutations in NOTCH1 and FBXW7 in 79 cases of Swedish childhood T-ALL treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL-1992 and ALL-2000 protocols.

Pharmacogenetically based dosing of thiopurines in childhood acute lymphoblastic leukemia: influence on cure rates and risk of second cancer.

Background: Previous studies have indicated that patients with thiopurine methyltransferase (TPMT) low activity (TPMT(LA)) have reduced risk of relapse but increased risk of second malignant neoplasm (SMN) compared to patients with TPMT wild-type (TPMT(WT)) when treated with 6 MP maintenance therapy starting doses of 75 mg/m(2)/day. To reduce SMN risk, 6MP starting doses were reduced to 50 mg/m(2)/day for patients with TPMT heterozygosity in the Nordic Society of Paediatric Haematology and Oncology (NOPHO) ALL2000 protocol.

Procedure: We explored the pattern of SMN and relapse in the NOPHO ALL2000 protocol (n = 674) and NOPHO ALL92 protocol (n = 601) in relation to TPMT pheno- and/or genotype.

Genome-wide signatures of differential DNA methylation in pediatric acute lymphoblastic leukemia.

Background: Although aberrant DNA methylation has been observed previously in acute lymphoblastic leukemia (ALL), the patterns of differential methylation have not been comprehensively determined in all subtypes of ALL on a genome-wide scale. The relationship between DNA methylation, cytogenetic background, drug resistance and relapse in ALL is poorly understood.

Results: We surveyed the DNA methylation levels of 435,941 CpG sites in samples from 764 children at diagnosis of ALL and from 27 children at relapse.

Antithrombin deficiency after prolonged asparaginase treatment in children with acute lymphoblastic leukemia.

Children with acute lymphoblastic leukemia (ALL) have several risk factors for deep venous thromboses (DVTs) such as central venous catheters and asparaginase (ASP), related antithrombin (AT) deficiency. After introduction of a new standard and intermediate-risk ALL treatment protocol with prolonged continuous ASP treatment, two symptomatic DVTs in 10 patients were observed at the Children's Hospital, Helsinki, Finland. To prevent further thrombotic complications yet ensuring continuous exposure to ASP, an AT substitution strategy was adopted in Helsinki.

Methotrexate binds to recombinant thiopurine S-methyltransferase and inhibits enzyme activity after high-dose infusions in childhood leukaemia.

Purpose: Important drugs in the treatment of childhood acute lymphoblastic leukaemia (ALL) are 6-mercaptopurine (6-MP) and methotrexate (MTX). Thiopurine methyltransferase (TPMT) is a polymorphic enzyme causing variability in 6-MP response and toxicity. The aim of this study was to investigate the fluctuation in TPMT enzyme activity over time and the effect of high-dose MTX infusions on TPMT enzyme activity and 6-MP metabolites in paediatric ALL patients.

Requirement of apoptotic protease-activating factor-1 for bortezomib-induced apoptosis but not for Fas-mediated apoptosis in human leukemic cells.

Bortezomib is a highly selective inhibitor of the 26S proteasome and has been approved for clinical use in the treatment of relapsing and refractory multiple myeloma and mantle cell lymphoma. Clinical trials are also underway to assess the role of bortezomib in several other human malignancies, including leukemia. However, the mechanism(s) by which bortezomib acts remain to be fully understood.

Involvement of miR17 pathway in glucocorticoid-induced cell death in pediatric acute lymphoblastic leukemia.

Analysis of the microRNA transcriptome following dexa- methasone treatment of the acute lymphocytic leukemia (ALL) cell line RS4;11 showed a global down-regulation of microRNA levels. MIR17HG was rapidly down-regulated following treatment, with chromatin immunoprecipitation (ChIP) analysis demonstrating the promoter to be a direct target of glucocorticoid (GC)-transcriptional repression and revealing the miR17-92 cluster as a prime target for dexamethasone-induced repression. The loss of miR17 family expression and concomitant increases in the miR17 target Bim occurred in an additional ALL cell line SUP-B15 but not in the dexamethasone-resistant REH.

Donor cell-derived acute myeloid leukemia after second allogenic cord blood transplantation in a patient with Fanconi anemia.

DCL following hematopoietic stem cell transplantation has been reported in approximately 5% of all leukemic relapses. There have been several reports on DCL, mainly AML after umbilical cord blood transplantation. In this case study, we present a young boy diagnosed with Fanconi anemia who underwent an umbilical cord blood transplantation.

Intravenous pamidronate treatment improves growth in prepubertal osteogenesis imperfecta patients.

Background/aims: Pamidronate is widely used to treat pediatric patients with osteogenesis imperfecta (OI). We aimed at delineating the effects of monthly pamidronate therapy on the growth of different body segments in prepubertal OI patients.

Methods: The study included 14 prepubertal patients (12 boys, 2 girls) with mild forms of OI (type I and IV).

Risk factors for treatment related mortality in childhood acute lymphoblastic leukaemia.

Background: In spite of major improvements in the cure rate of childhood acute lymphoblastic leukaemia (ALL), 2-4% of patients still die from treatment related complications.

Procedure: We investigated the pattern of treatment related deaths (TRDs) and possible risk factors in the NOPHO ALL-92 and ALL-2000 protocols. Fifty-five TRDs were identified among the 1,645 ALL-92 patients and 33 among the 1,090 ALL-2000 patients.

Minimal residual disease assessment in childhood acute lymphoblastic leukaemia: a Swedish multi-centre study comparing real-time polymerase chain reaction and multicolour flow cytometry.

Minimal residual disease (MRD) assessment is a powerful prognostic factor for determining the risk of relapse in childhood acute lymphoblastic leukaemia (ALL). In this Swedish multi-centre study of childhood ALL diagnosed between 2002 and 2006, the MRD levels were analysed in 726 follow-up samples in 228 children using real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged immunoglobulin/T-cell receptor genes and multicolour flow cytometry (FCM). Using an MRD threshold of 0·1%, which was the sensitivity level reached in all analyses, the concordance between RQ-PCR and FCM MRD values at day 29 was 84%.

Interphase fluorescent in situ hybridization deletion analysis of the 9p21 region and prognosis in childhood acute lymphoblastic leukaemia (ALL): results from a prospective analysis of 519 Nordic patients treated according to the NOPHO-ALL 2000 protocol.

Interphase fluorescent in situ hybridization (FISH) was applied on diagnostic BM smears from 519 children with acute lymphoblastic leukaemia (ALL) in order to establish the frequency and prognostic importance of 9p21 deletion in children enrolled in the Nordic Society of Paediatric Haematology and Oncology (NOPHO) - 2000 treatment protocol. Among the patients, 452 were diagnosed with B-cell precursor (BCP)-ALL and 66 with T-ALL. A higher incidence of 9p21 deletions was found in T-ALL (38%) compared to BCP-ALL (15·7%).

High white blood cell count at diagnosis of childhood acute lymphoblastic leukaemia: biological background and prognostic impact. Results from the NOPHO ALL-92 and ALL-2000 studies.

Prognostic impact of peripheral blood white blood cell count (WBC) at the diagnosis of childhood acute lymphoblastic leukaemia (ALL) was evaluated in a population-based consecutive series of 2666 children aged 1-15 treated for ALL between 1992 and 2008 in the five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden). Ten-year event-free (pEFS(10 y)) survival and overall (pOS(10 y)) survival were 0.75 ± 0.

In vitro cellular drug resistance adds prognostic information to other known risk-factors in childhood acute lymphoblastic leukemia.

Leukemic cells from 230 children with newly diagnosed B-cell precursor ALL were tested for in vitro drug resistance to a panel of anti-cancer drugs. Minimal residual disease (MRD) was measured by RQ-PCR. During follow-up, 24 relapses occurred in the 159 children with MRD <0.

Respiratory viruses, a common microbiological finding in neutropenic children with fever.

Background: Febrile neutropenia is a common complication in children undergoing chemotherapy for malignancies. A microbial agent is only identified in 15-30% of the fever episodes and corresponds mostly to bacterial findings.

Objective: To investigate viral infections as possible etiologic agents in episodes of febrile neutropenia.

DNA methylation for subtype classification and prediction of treatment outcome in patients with childhood acute lymphoblastic leukemia.

Despite improvements in the prognosis of childhood acute lymphoblastic leukemia (ALL), subgroups of patients would benefit from alternative treatment approaches. Our aim was to identify genes with DNA methylation profiles that could identify such groups. We determined the methylation levels of 1320 CpG sites in regulatory regions of 416 genes in cells from 401 children diagnosed with ALL.