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Background The emergence and spread of malaria drug resistance have resulted in the need to understand disease mechanisms and importantly identify essential targets and potential drug candidates. Malaria infection involves the complex interaction between the host and pathogen, thus, functional interactions between human and Plasmodium falciparum is essential to obtain a holistic view of the genetic architecture of malaria. Several functional interaction studies have extended the understanding of malaria disease and integrating such datasets would provide further insights towards understanding drug resistance and/or genetic resistance/susceptibility, disease pathogenesis, and drug discovery. Methods This study curated and analysed data including pathogen and host selective genes, host and pathogen protein sequence data, protein–protein interaction datasets, and drug data from literature and databases to perform human-host and P. falciparum network-based analysis. An integrative computational framework is presented that was developed and found to be reasonably accurate based on various evaluations, applications, and experimental evidence of outputs produced, from data-driven analysis. Results This approach revealed 8 hub protein targets essential for parasite and human host-directed malaria drug therapy. In a semantic similarity approach, 26 potential repurposable drugs involved in regulating host immune response to inflammatory-driven disorders and/or inhibiting residual malaria infection that can be appropriated for malaria treatment. Further analysis of host–pathogen network shortest paths enabled the prediction of immune-related biological processes and pathways subverted by P. falciparum to increase its within-host survival. Conclusions Host–pathogen network analysis reveals potential drug targets and biological processes and pathways subverted by P. falciparum to enhance its within malaria host survival. The results presented have implications for drug discovery and will inform experimental studies.

Background: Sickle cell disease (SCD) is a blood disorder caused by a point mutation on the beta globin gene resulting in the synthesis of abnormal hemoglobin. Fetal hemoglobin (HbF) reduces disease severity, but the levels vary from one individual to another. Most research has focused on common variants which differ across populations and hence do not fully account for HbF variation. Methods: We investigated rare and common genetic variants that influence HbF levels in 14 SCD patients to elucidate variants and pathways in SCD patients with extreme HbF levels (≥7.7% for high HbF) and (≤2.5% for low HbF) in Tanzania. We performed targeted next generation sequencing (Illumina_Miseq) covering exonic and other significant fetal hemoglobin-associated loci, including BCL11A, MYB, HOXA9, HBB, HBG1, HBG2, CHD4, KLF1, MBD3, ZBTB7A and PGLYRP1.Results: Results revealed a range of genetic variants, including bi-allelic and multi-allelic SNPs, frameshift insertions and deletions, some of which have functional importance. Notably, there were significantly more deletions in individuals with high HbF levels (11% vs 0.9%). We identified deletions with high HbF levels and frameshift insertions in individuals with low HbF. CHD4 and MBD3 genes, interacting in the same sub-network, were identified to have a significant number of pathogenic or non-synonymous mutations in individuals with low HbF levels, suggesting an important role of epigenetic pathways in the regulation of HbF synthesis. Conclusions: This study provides new insights in selecting essential variants and identifying potential biological pathways associated with extreme HbF levels in SCD using multiple genomic variants associated with HbF in SCD.

Treatment-related mortality is common among children with acute lymphoblastic leukemia (ALL) treated in poor-resource settings. We applied a simplified flow cytometric assay to identify patients with precursor B-cell ALL (B-ALL) at very low risk (VLR) of relapse and treated them with a reduced-intensity treatment plan (RELLA05). VLR criteria include favorable presenting features (age ≥ 1 and < 10 years), white blood cell count of

BackgroundRenal dysfunctions are associated with increased morbidity and mortality in sickle cell disease (SCD). Early detection and subsequent management of SCD patients at risk for renal failure and dysfunctions are essential, however, predictors that can identify patients at risk of developing renal dysfunction are not fully understood.MethodsIn this study, we have investigated the association of 31 known kidney dysfunctions-related variants detected in African Americans from multi-ethnic genome wide studies (GWAS) meta-analysis, to kidney-dysfunctions in a group of 413 Cameroonian patients with SCD. Systems level bioinformatics analyses were performed, employing protein-protein interaction networks to further interrogate the putative associations.ResultsUp to 61% of these patients had micro-albuminuria, 2.4% proteinuria, 71% glomerular hyperfiltration, and 5.9% had renal failure. Six variants are significantly associated with the two quantifiable phenotypes of kidney dysfunction (eGFR and crude-albuminuria): A1CF-rs10994860 (P = 0.02020), SYPL2-rs12136063 (P = 0.04208), and APOL1 (G1)-rs73885319 (P = 0.04610) are associated with eGFR; and WNT7A-rs6795744 (P = 0.03730), TMEM60-rs6465825 (P = 0.02340), and APOL1 (G2)-rs71785313 (P = 0.03803) observed to be protective against micro-albuminuria. We identified a protein-protein interaction sub-network containing three of these gene variants: APOL1, SYPL2, and WNT7A, connected to the Nuclear factor NF-kappa-B p105 subunit (NFKB1), revealed to be essential and might indirectly influence extreme phenotypes. Interestingly, clinical variables, including body mass index (BMI), systolic blood pressure, vaso-occlusive crisis (VOC), and haemoglobin (Hb), explain better the kidney phenotypic variations in this SCD population.ConclusionThis study highlights a strong contribution of haematological indices (Hb level), anthropometric variables (BMI, blood pressure), and clinical events (i.e., vaso-occlusive crisis) to kidney dysfunctions in SCD, rather than known genetic factors. Only 6/31 characterised gene-variants are associated with kidney dysfunction phenotypes in SCD samples from Cameroon. The data reveal and emphasise the urgent need to extend GWAS studies in populations of African ancestries living in Africa, and particularly for kidney dysfunctions in SCD.

Human tuberculosis (TB) is caused mainly by Mycobacterium tuberculosis (MTB) and M. africanum (MAF) remains a major global health threat. The varying response of different host to contact with the TB bacteria, indicates the importance of host genetics in susceptibility to TB disease. We explored the association among selected human/host genomic variants and disease caused by the two causative pathogens in Ghana through a case control study. MTBC isolates (323) recovered from pulmonary TB patients recruited between 2016 and 2018 were genotyped using spoligotyping. A selection of 29 SNPs from MTB-related genes with high frequency among African populations were genotyped using a TaqMan® SNP Genotyping Assay and iPLEX Gold Sequenom Mass Genotyping Array. Associations between MTBC lineages and host variables were assessed using univariate and multivariate logistic regression. The prevalence of MTB and Maf among the participants were 79% and 21% respectively. Association analysis between the controls and MAF showed that rs2695342 variant on the SIC11A1 gene have the propensity to confer susceptibility to MAF infections (P = 0.093, OR = 8.35, 95% CI = 0.70 – 99.24) whilst the rs17048476 (P = 0.088, OR = 1.57, 95% CI = 0.93 – 2.63) and rs1482868 (P = 0.095, OR = 0.60, 95% CI = 0.33 – 1.09) were observed to be only suggestive. Our findings implicate SLC11A1 as a potential susceptibility gene of substantial interest for TB caused by MAF which is an important pathogen in West Africa and highlight the need for in-depth host pathogen studies in West Africa.

Legacy data show that ∼40% of children with acute lymphoblastic leukemia (ALL) were cured with limited antimetabolite-based chemotherapy regimens. However, identifying patients with very-low-risk (VLR) ALL remains imprecise. Patients selected based on a combination of presenting features and a minimal residual disease (MRD) level

The ongoing Ebola virus disease (EVD) outbreak in the eastern Democratic Republic of Congo is raising unprecedented health concerns, with potential to wipe out large proportions of the population in this part of the world. Established control strategies to contain the outbreak are failing due to several reasons, including lack of a data/information repository and ongoing violence and armed conflict. In this paper, we propose a potential roadmap from a computational perspective, which may provide solutions to contain the current outbreak, predict future outbreaks and facilitate development of novel solutions and therapeutics. This roadmap includes the implementation of an integrated information system through a centralized data coordinating center unifying existing and future EVD data and information to enhance innovative EVD translational research. This work will leverage off tools, guidelines and protocols developed by established data coordinating centers based in Africa or centers that address infectious disease outbreaks. The proposed EVD computational strategy is expected to inform optimal strategies at the national or global level towards strengthened responses to future EVD outbreaks and potential emergency of therapy resistant. Keywords: Ebola virus disease, rVSV-ZEBOV, Monoclonal antibody, Translational research, FAIR data

Hearing impairment (HI) is a common sensory disorder that is defined as the partial or complete inability to detect sound in one or both ears. This diverse pathology is associated with a myriad of phenotypic expressions and can be non-syndromic or syndromic. HI can be caused by various genetic, environmental, and/or unknown factors. Some ontologies capture some HI forms, phenotypes, and syndromes, but there is no comprehensive knowledge portal which includes aspects specific to the HI disease state. This hampers inter-study comparability, integration, and interoperability within and across disciplines. This work describes the HI Ontology (HIO) that was developed based on the Sickle Cell Disease Ontology (SCDO) model. This is a collaboratively developed resource built around the 'Hearing Impairment' concept by a group of experts in different aspects of HI and ontologies. HIO is the first comprehensive, standardized, hierarchical, and logical representation of existing HI knowledge. HIO allows researchers and clinicians alike to readily access standardized HI-related knowledge in a single location and promotes collaborations and HI information sharing, including epidemiological, socio-environmental, biomedical, genetic, and phenotypic information. Furthermore, this ontology illustrates the adaptability of the SCDO framework for use in developing a disease-specific ontology.

Hydroxyurea (HU) is clinically beneficial in sickle cell disease (SCD) through fetal hemoglobin (HbF) induction; however, the mechanism of HU is not yet fully elucidated. Selected miRNAs have been associated with HU-induced HbF production. We have investigated differential HU-induced global miRNA expression in peripheral blood of adult SCD patients in patients from Congo, living in South Africa. We found 22 of 798 miRNAs evaluated that were differentially expressed under HU treatment, with the majority (13/22) being functionally associated with HbF-regulatory genes, including BCL11A (miR-148b-3p, miR-32-5p, miR-340-5p, and miR-29c-3p), MYB (miR-105-5p), and KLF-3 (miR-106b-5), and SP1 (miR-29b-3p, miR-625-5p, miR-324-5p, miR-125a-5p, miR-99b-5p, miR-374b-5p, and miR-145-5p). The preliminary study provides potential additional miRNA candidates for therapeutic exploration.

Sickle cell disease (SCD) is one of the most common monogenic diseases in humans with multiple phenotypic expressions that can manifest as both acute and chronic complications. Although described more than a century ago, challenges in comprehensive disease management and collaborative research on this disease are compounded by the complex molecular and clinical phenotypes of SCD, environmental and psychosocial factors, limited therapeutic options and ambiguous terminology. This ambiguous terminology has hampered the integration and interoperability of existing SCD knowledge, and SCD research translation. The SCD Ontology (SCDO), which is a community-driven integrative and universal knowledge representation system for SCD, overcomes this issue by providing a controlled vocabulary developed by a group of experts in both SCD and ontology design. SCDO is the first and most comprehensive standardized human- and machine-readable resource that unambiguously represents terminology and concepts about SCD for researchers, patients and clinicians. It is built around the central concept ‘hemoglobinopathy’, allowing inclusion of non-SCD haemoglobinopathies, such as thalassaemias, which may interfere with or influence SCD phenotypic manifestations. This collaboratively developed ontology constitutes a comprehensive knowledge management system and standardized terminology of various SCD-related factors. The SCDO will promote interoperability of different research datasets, facilitate seamless data sharing and collaborations, including meta-analyses within the SCD community, and support the development and curation of data-basing and clinical informatics in SCD.

Background The Chilean population is ethnically diverse, and more than 50% of children referred for hematopoietic stem cell transplantation (HSCT) lack a suitable donor. Procedure To expand the donor pool, we assessed the feasibility, tolerance, and efficacy of using a haploidentical (HI) donor and a reduced-intensity conditioning regimen for high-risk pediatric leukemia. This study was facilitated by technology transfer from St. Jude Children's Research Hospital over the 2 preceding years. Results Between March 2006 and April 2009, 10 patients (median age, 9.8 years) received T cell-depleted grafts at Calvo Mackenna Hospital in Santiago. Median cell doses were CD34+: 7.45 × 106/kg (range, 4.00–20.20 × 106/kg); CD3+: 0.88 × 105/kg (0.11–1.35 × 105/kg); and CD56+: 71.30 × 106/kg (31.50–131.80 × 106/kg). Nine patients experienced complete engraftment; six of the nine remain alive and clinically well 13–50 months post-HSCT. Three patients died after bone marrow relapse, while only one died of transplant-related causes. Virus reactivation was the main post-transplant complication: 5/10 had positive CMV PCR but none had CMV disease. One patient developed acute GvHD > grade II and only one had chronic GvHD. Conclusions HI-HSCT is feasible in our setting, offers a rational treatment option, and expands the donor pool significantly for children with high-risk leukemia in a developing country. This information is especially relevant to other ethnically diverse populations that are poorly represented in international donor registries. Pediatr Blood Cancer 2012; 59: 895–901. © 2012 Wiley Periodicals, Inc.

Bone marrow normal lymphoid progenitors (CD19+, CD10+, and/or CD34+) are exquisitely sensitive to corticosteroids and other antileukemic drugs. We hypothesized that, in patients with B-lineage acute lymphoblastic leukemia (ALL), cells with this phenotype detected early in treatment should be leukemic rather than normal. We therefore developed a simple and inexpensive flow cytometric assay for such cells and prospectively applied it to bone marrow samples collected on day 19 from 380 children with B-lineage ALL. In 211 patients (55.5%), these cells represented 0.01% or more of the mononuclear cells; results correlated remarkably well with those of more complex flow cytometric and molecular minimal residual disease (MRD) evaluations. Among 84 uniformly treated children, the 10-year incidence of relapse or remission failure was 28.8% ± 7.1% (SE) for the 42 patients with 0.01% or more leukemic cells on day 19 detected by the simplified assay versus 4.8% ± 3.3% for the 42 patients with lower levels (P = .003). These assay results were the strongest predictor of outcome, even after adjustment for competing clinicobiologic variables. Thus, this new assay would enable most treatment centers to identify a high proportion of children with ALL who have an excellent early treatment response and a high likelihood of cure. (Blood. 2006;108:97-102)

Twenty-eight children with Down syndrome (DS) and acute lymphocytic leukemia (ALL) were compared to non-DS control leukemics matched by age, white blood cell (WBC) count, and treatment protocol to evaluate presenting manifestations, toxicity, and outcome. The DS children with ALL did not have unique clinical or biologic characteristics to distinguish their disease from that of non-DS patients. Eleven of the DS patients had successfully banded cytogenetic studies of their leukemic cells with the distribution of model chromosome number of 46 (n = 1), 47 (2), 48 (5), and greater than 50 (3). The abnormal leukemic line involved an isochromosome of the long arm of chromosome 9[i(9q)] in 3 cases. Multiagent chemotherapies induced complete remissions in 25 patients (85%), yet overall 5 year event-free survival was only 23 +/- 8% when compared to 64 +/- 9% for control children receiving similar therapies (P less than 0.01). A significant cause of treatment failure was late marrow recurrence in the DS children. Host toxicity was striking in these children. Severe congenital heart disease present in one-third contributed to 2 deaths during antileukemia therapy. Hyperglycemia secondary to diabetogenic agents and repeated bronchitis were common toxicities. Intolerance to the antifolate methotrexate with severe gastrointestinal and skin toxicities was universal. We conclude that the poor prognosis for the child with DS and ALL stems in part from their increased risk of complications and toxicity from intensive modern leukemia therapies, specifically antifolates.

Background Although most pediatric oncologists obtain routine blood counts in patients who have completed treatment for acute lymphoblastic leukemia (ALL), the value of this practice is unproven. We therefore sought to determine if detection of relapse by blood counts before the onset of symptoms provided any clinical benefit. Procedures We performed a retrospective review of 72 patients with ALL who suffered isolated or combined hematologic relapses after the completion of therapy. We compared attainment of second remission and survival after relapse among patients who were asymptomatic and diagnosed by routine blood count, those who had symptoms suggestive of relapse and were diagnosed at the time of a scheduled follow-up, and those whose relapse was diagnosed because of the appearance of symptoms. Results Only 11% of patients who suffered a relapse were asymptomatic at the time of relapse and diagnosed solely by routine blood counts. There were no significant differences in the survival distributions for the three groups of patients. Conclusions In this cohort of patients with relapsed ALL, we found no evidence that detection of relapse by routine blood counts before the onset of symptoms leads to a better outcome. © 2004 Wiley-Liss, Inc.

St Jude Total Therapy Study XIIIB for childhood acute lymphoblastic leukemia (ALL) incorporated more stringent risk classification, early intensification of intrathecal chemotherapy, reinduction treatment, and the addition of dexamethasone to postremission therapy to increase the proportion of event-free survivors without jeopardizing their quality of life. Cranial irradiation was reserved for the 12% of patients who had T-cell ALL and a presenting leukocyte count of 100 × 109/L or more, or CNS-3 (5 or more leukocytes/μL with identifiable blast cells in an atraumatic sample or the presence of cranial nerve palsy) status. Among the 247 consecutive patients enrolled in the study, 117 were classified as having lower-risk leukemia and received mainly antimetabolite-based continuation therapy; the 130 cases with higher-risk leukemia received more intensive continuation chemotherapy with multiple drug pairs administered in weekly rotation. The 5-year event-free survival estimate was 80.8% ± 2.6% (SE); the 8-year rate was 78.6% ± 5.8%. The 5-year cumulative risk of an isolated central nervous system (CNS) relapse was 1.7% ± 0.8%, and that of isolated plus combined CNS relapse was 3.0% ± 1.1%. The 5-year cumulative risks of etoposide-related myeloid malignancies were 1.8% ± 1.3% in the lower-risk patients who received a cumulative dose of 1.2 g/m2 and 5.0% ± 2.0% in the higher-risk patients who received a cumulative dose of up to 14.4 g/m2 (P = .18). Independent adverse prognostic features included the presence of MLL-AF4 or BCR-ABL fusion gene and minimal residual leukemia of 0.01% or more at the end of the 6-week remission induction phase. Our results suggest the efficacy of early intensification of intrathecal chemotherapy and provide the basis for studies omitting cranial irradiation altogether. (Blood. 2004;104:2690-2696)

We evaluated the clinical response to low-dose etoposide in relapsed acute lymphoblastic leukemia (ALL). Of the 45 patients with ALL in first bone marrow relapse enrolled on the ALL R15 protocol, 44 had received epipodophyllotoxins during frontline therapy. In the first week of remission induction therapy, patients received etoposide (50 mg/m(2) per day) administered orally as a single agent once or twice daily. On Day 8, patients started to receive dexamethasone, vincristine, and L-asparaginase. Etoposide was administered until Day 22. Two courses of consolidation therapy were followed by continuation therapy or hematopoietic stem cell transplantation. After 7 days of single-agent etoposide treatment, peripheral blast cell counts (P=0.013) and percentages of bone marrow blasts (P=0.016) were significantly reduced. In all, 38 (84.4%) attained second remission. Only time to relapse was significantly associated with outcome (P=0.025): the 5-year event-free survival estimates (+/-se) were 52.0+/-9.6% for those with late relapse and 20.0+/-8.0% for those with early relapse. We conclude that low-dose etoposide administered orally has a cytoreductive effect in relapsed ALL.

Using flow cytometric techniques capable of detecting 0.01% leukemic cells, we prospectively studied minimal residual disease (MRD) in patients with acute lymphoblastic leukemia (ALL) after first relapse. At the end of remission reinduction, 41 patients had a bone marrow sample adequate for MRD studies; 35 of these were in morphologic remission. Of the 35 patients, 19 (54%) had MRD >/=0.01%, a finding that was associated with subsequent leukemia relapse. The 2-year cumulative incidence of second leukemia relapse was 70.2+/-12.3% for the 19 MRD-positive patients and 27.9+/-12.4% for the 16 MRD-negative patients (P=0.008). Among patients with a first relapse off therapy, 2-year second relapse rates were 49.1+/-17.8% in the 12 MRD-positive and 0% in the 11 MRD-negative patients (P=0.014); among those who received only chemotherapy after first relapse, the 2-year second relapse rates were 81.5+/-14.4% (n=12) and 25.0+/-13.1% (n=13), respectively (P=0.004). Time of first relapse and MRD were the only two significant predictors of outcome in a multivariate analysis. We conclude that MRD assays should be used to guide the selection of postremission therapy in patients with ALL in first relapse.

Purpose: To study the pharmacokinetics and pharmacodynamics of once- versus twice-daily oral etoposide in children with relapsed or refractory acute lymphoblastic leukemia (ALL). Patients and Methods: Fifty-eight patients were randomly assigned to etoposide at 50 mg/m2/d with once- versus twice-daily doses for 22 days. On day 8, vincristine, asparaginase, and dexamethasone were started. Etoposide pharmacokinetics and pharmacodynamics were studied for 47, 28, and 26 patients on day 1, 8, and 22, respectively, of remission reinduction therapy. Results: Of 48 patients with pharmacokinetic data, 42 (87.5%) achieved complete remission, three (6.3%) failed to achieve remission, and three (6.3%) died during induction. Median etoposide day 8 area under concentration-time curve (AUC) and cumulative AUC tended to be greater (P = .06 and P = .07, respectively) in patients (n = 23) who achieved complete remission (24 and 522 μmol/L • h, respectively) than in patients (n = 3) who did not (14 and 303 μmol/L • h, respectively). Three of eight patients with plasma concentrations exceeding 1.7 μM (1 μg/mL) for more than 8 hours daily, compared with one of 20 patients with concentrations exceeding 1.7 μM for ≤ 8 hours daily, were unable to receive all 22 days of etoposide because of toxicity. There was no difference in the AUC at day 1 or day 8 with once- versus twice-daily doses (P = .55 and P = .86, respectively). Conclusion: A pharmacodynamic relationship exists between systemic etoposide exposure and response to therapy when oral etoposide is used as part of remission induction regimens for relapsed or refractory childhood ALL.

Methotrexate (MTX) is one of the most widely used drugs for the treatment of childhood acute lymphoblastic leukemia (ALL). Interindividual differences in lymphoblast accumulation of MTX and its active metabolites, methotrexate polyglutamates (MTXPG), may contribute to the effectiveness of treatment among ALL subtypes. To better understand these differences in MTXPG accumulation, we developed a model to characterize the cellular influx and efflux of MTX, formation of MTXPG by the addition of glutamyl residues catalyzed by FPGS (folylpolyglutamate synthetase), and cleavage of glutamyl residues from MTXPG by GGH (gamma-glutamyl hydrolase). The model was fitted to in vivo intracellular MTXPG concentrations measured serially in leukemic blasts from 20 newly diagnosed patients with ALL treated with 24-h intravenous infusions of MTX. The observed median concentrations of total MTXPG at 44 h was higher in B-lineage than in T-cell ALL (1706 vs 518 pmol/10(9) cells, P0.025), consistent with the higher estimated Vmax for FPGS activity in B-lineage vs T-lineage blasts (414 vs 93 pmol/10(9) cells/h, P0.008). Simulations based on the model-estimated parameters indicated greater accumulation of MTX, MTXPGs (MTXPG(2-7)) and total MTX (MTXPG(1-7)) with longer MTX infusions and with higher MTX doses, with the highest concentrations in hyperdiploid B-lineage, intermediate in non-hyperdiploid B-lineage, and lowest in T-cell ALL. These differences provide mechanistic and treatment insights for lineage and ploidy differences in MTXPG accumulation in human leukemia cells in vivo.

Early clearance of leukemic cells is a favorable prognostic indicator in childhood acute lymphoblastic leukemia (ALL). However, identification of residual leukemic cells by their morphologic features is subjective and lacks sensitivity. To improve estimates of leukemia clearance, we applied flow cytometric techniques capable of detecting 1 leukemic cell in 10 000 or more normal cells and prospectively measured residual leukemia in bone marrow samples collected on day 19 of remission-induction chemotherapy from 248 children with newly diagnosed ALL. In 134 samples (54.0%), we identified at least 0.01% leukemic cells (0.01%-< 0.1% in 51 samples [20.6%], 0.1%-< 1% in 36 [14.5%], and ≥ 1% in 47 [19.0%]). Among 110 children treated within a single chemotherapy program, the 5-year mean ± SE cumulative incidence of relapse or failure to achieve remission was 32.2% ± 6.5% for the 59 patients with 0.01% residual leukemic cells or greater on day 19 and 6.0% ± 3.4% for the 51 patients with less than 0.01% leukemic cells (P

Mental stress (MS) reduces diastolic function (DF) and may lead to congestive heart failure with preserved systolic function. Whether brain natriuretic hormone (brain natriuretic peptide [BNP]) mediates the relationship of MS with DF is unknown.One hundred sixty individuals aged 30 to 50 years underwent 2-hour protocol of 40-minute rest, videogame stressor and recovery. Hemodynamics, pro-BNP samples and DF indices were obtained throughout the protocol. Separate regression analyses were conducted using rest and stress E/A, E' and E/E' as dependent variables. Predictor variables were entered into the stepwise regression models in a hierarchical fashion. At the first level, age, sex, race, height, body mass index, pro-BNP and left ventricular mass (LVM) were permitted to enter the models. The second level consisted of systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR). The final level contained cross-product terms of race by SBP, DBP and HR.E/A ratio was lower during stress compared to rest and recovery (P0.01). Resting E/A ratio was predicted by a regression model of age (-0.31), pro-BNP (0.16), HR (-0.40) and DBP (-0.23) with an R² = 0.33. Stress E/A ratio was predicted by age (-0.24), pro-BNP (0.08), HR (-0.38) and SBP (-0.21) with total R² = 0.22. Resting E' model consisted of age (-0.22), pro-BNP (0.26), DBP (-0.27) and LVM (-0.15) with an R² = 0.29. Stress E' was predicted by age (-0.18), pro-BNP (0.35) and LVM (-0.18) with an R² = 0.18. Resting E/E' was predicted by race (0.17, BW) and DBP (0.24) with an R² = 0.10. Stress E/E' consisted of pro-BNP (-0.36), height (-0.26) and HR (-0.21) with an R² = 0.15.pro-BNP predicts both resting and stress DF, suggesting that lower BNP during MS may be a marker of diastolic dysfunction in apparently healthy individuals.

Cure rates for pediatric acute lymphoblastic leukemia differ markedly in higher- and lower-income countries due to disparate hospital infrastructure and resources. Where means are limited, treatment-related mortality is higher and compliance may be suboptimal. Upfront risk assignment is aimed at individualizing therapy according to presenting features in order to avoid over- or under-treatment. However, the necessary technical resources and expertise are not always readily available. The authors provide suggestions for management of childhood acute lymphoblastic leukemia in developing nations. To improve patient care locally, the authors recommend that communication technology be used to sustain partnerships between sponsoring and partner pediatric oncology programs. The aims of these collaborations should be to prioritize resources, identify existing problems and reduce treatment intensity and hence treatment-related morbidity and mortality in patients at lower risk of relapse.

We assessed the clinical and treatment factors that predispose survivors of childhood acute lymphoblastic leukemia (ALL) to low bone mineral density (BMD). Using quantitative computed tomography, we determined the frequency of low BMD (defined as >1.645 standard deviations (SD) below the mean) in leukemia survivors treated with multiagent chemotherapy including prednisone and antimetabolite. All participants had completed therapy at least 4 years earlier, remained in continuous complete remission, and had no second malignancies. We statistically correlated BMD results with patient characteristics and treatment histories. Among 141 survivors (median age, 15.9 years; median time after diagnosis, 11.5 years), median BMD z score was -0.78 SD (range, -3.23 to 3.61 SDs). Thirty participants (21%; 95% confidence interval, 15% to 29%) had abnormally low BMD, a proportion significantly (P < 0.0001) greater than the expected 5% in normal populations. Risk factors for BMD decrements included male sex (P = 0.038), Caucasian race (P < 0.0001), and cranial irradiation (P= 0.0087). BMD inversely correlated with cranial irradiation dose. BMD z scores of patients who received higher doses of antimetabolites were lower than those of other patients. Childhood ALL survivors are at risk to have low BMD, especially males, Caucasians, and those who received cranial irradiation.

The effect of traumatic lumbar puncture at the time of initial diagnostic workup on treatment outcome in children with newly diagnosed acute lymphoblastic leukemia (ALL) was investigated. The findings of the first 2 lumbar punctures performed on 546 patients with newly diagnosed ALL treated on 2 consecutive front-line studies (1984-1991) at St Jude Children's Research Hospital were retrospectively reviewed. Lumbar punctures were performed at the time of diagnosis and again for the instillation of first intrathecal chemotherapy. The event-free survival (EFS) experience for patients with 1 cerebrospinal fluid (CSF) sample contaminated with blast cells was worse than that for patients with no contaminated CSF samples (P = .026); that of patients with 2 consecutive contaminated CSF samples was particularly poor (5-year EFS = 46 ± 9%). In a Cox multiple regression analysis, the strongest prognostic indicator was 2 consecutive contaminated CSF samples, with a hazard ratio of 2.39 (95% confidence interval, 1.36-4.20). These data indicate that contamination of CSF with circulating leukemic blast cells during diagnostic lumbar puncture can adversely affect the treatment outcome of children with ALL and is an indication to intensify intrathecal therapy.

By using rapid flow cytometric techniques capable of detecting one leukemic cell in 104 normal cells, we prospectively studied minimal residual disease (MRD) in 195 children with newly diagnosed acute lymphoblastic leukemia (ALL) in clinical remission. Bone marrow aspirates (n = 629) were collected at the end of remission induction therapy and at 3 intervals thereafter. Detectable MRD (ie, ≥0.01% leukemic mononuclear cells) at each time point was associated with a higher relapse rate (P

Summary Background Many antileukaemic agents or their metabolites are inactivated by liver enzymes. Most anticonvulsant drugs induce drug-metabolising enzymes and thereby increase the clearance of anticancer agents. We investigated whether anticonvulsants compromise the efficacy of cancer chemotherapy. Methods We identified whom of 716 children treated consecutively for acute lymphoblastic leukaemia at a single academic hospital in the USA between 1984 and 1994 received treatment for 30 days or longer with anticonvulsants (phenytoin, phenobarbital, carbamazepine, or a combination) at the same time as antileukaemic therapy. Cox's proportional-hazards models were used to assess the prognostic significance of anticonvulsants on event-free survival and risk of haematological and central-nervous-system (CNS) relapse, with stratification for treatment protocol. Findings 40 (5·6%) of 716 patients received anticonvulsants. Use of these drugs was associated with age over 10 years (p=0·003), non-hyperdiploid leukaemia (p=0·031), and T-cell immunophenotype (p=0·022). After adjustment for age and ploidy, anticonvulsant therapy was significantly related to worse event-free survival (hazard ratio 2·67 [95% CI 1·50–4·76]; p=0·0009), haematological relapse (3·40 [1·69–6·88]; p=0·0006), and CNS relapse (2·90 [1·01–8·28]; p=0·047) among the 566 patients with B-lineage leukaemia. No such associations were seen among the 114 patients with T-cell leukaemia (p=0·61, 0·35, and 0·53, respectively). Faster clearance of teniposide (p=0·0001) and methotrexate (p=0·051), but not cytarabine (p=0·26) was found among patients receiving anticonvulsants. Interpretation Long-term anticonvulsant therapy increases the systemic clearance of several antileukaemic agents and is associated with lower efficacy of chemotherapy. Alternatives to enzyme-inducing anticonvulsants should be prescribed for patients receiving chemotherapy for acute lymphoblastic leukaemia.

BACKGROUND Children with acute lymphoblastic leukemia (ALL) who experience hematologic recurrence while receiving chemotherapy or within 6 months after its cessation have a low cure rate. In this study (Pediatric Oncology Group Protocol 8303) two methods were examined for improving the outcome in these children. METHODS After remission induction with prednisone, vincristine, daunorubicin, and asparaginase (PVDA) and consolidation chemotherapy with teniposide and cytarabine, patients received weekly continuation chemotherapy with rotating pairs of drugs, comprised of teniposide and cytarabine and vincristine and cyclophosphamide. In addition, they were randomized to receive or not receive repeated reinduction with PVDA. Patients with matched sibling donors were allowed to receive allogeneic bone marrow transplantation (BMT) instead of continued chemotherapy. RESULTS Of 297 evaluable patients 258 (87%) achieved second complete hematologic remission. However, only 23 of these patients remained continuously free of leukemia ≥7 years after chemotherapy or BMT. Neither PVDA pulses nor BMT appeared to influence outcome at a statistically significant level. CONCLUSIONS The results of the current study confirm prior reports of the low cure rate of children with ALL who experience hematologic recurrence during initial therapy or shortly after its cessation. New approaches are needed to prevent and retreat hematologic recurrence in pediatric ALL patients. Cancer 2000;88:1166–74. © 2000 American Cancer Society.

Background: Patients with acute lymphoblastic leukemia are often treated with 6-mercaptopurine, and those with homozygous deficiency in thiopurine S-methyltransferase (TPMT) enzyme activity have an extreme sensitivity to this drug as a result of the accumulation of higher cellular concentrations of thioguanine nucleotides. We studied the metabolism, dose requirements, and tolerance of 6-mercaptopurine among patients with different TPMT phenotypes. Methods: We compared, by use of statistical modeling, 6-mercaptopurine pharmacology and tolerance in 180 patients who achieved remission on St. Jude Children’s Research Hospital Protocol Total XII composed of weekly methotrexate (40 mg/m 2 ) and daily oral 6-mercaptopurine (75 mg/m 2 ) given for 2.5 years, interrupted every 6 weeks during the first year for treatment with either high-dose methotrexate or teniposide plus cytarabine. Statistical tests were two-sided. Results: Erythrocyte concentrations of thioguanine nucleotides (pmol/8 ◊ 10 8 erythrocytes) were inversely related to TPMT enzyme activity (P

Purpose Hemolysis is so rarely associated with Bacillus cereus sepsis that only two very well documented cases have been reported. This article reports two unusual cases of Bacillus cereus sepsis with massive intravascular hemolysis in patients who had acute lymphoblastic leukemia (ALL). Patients and methods A 20-year-old woman who was 9 weeks pregnant experienced a relapse of ALL. A therapeutic abortion was performed. During week 4 of reinduction the patient had abdominal pain, nausea, and vomiting, with severe neutropenia but no fever. Her condition deteriorated rapidly with cardiovascular collapse, acute massive intravascular hemolysis, and death within hours of the onset of symptoms. Blood cultures were positive for Bacillus cereus. Postmortem histologic examination and cultures revealed Bacillus cereus and Candida albicans in multiple organs. The second patient, a 10-year-old girl, presented with relapsed T-cell ALL. In the second week of reinduction, she had abdominal pain followed by hypotension. Again, no fever was noted. Laboratory studies showed intravascular hemolysis 12 hours after admission. Aggressive support was promptly initiated. Despite disseminated intravascular coagulation; cardiovascular, hepatic, and renal failure; and multiple intracerebral hypodense lesions believed to be infarcts, the patient recovered fully and resumed reinduction therapy. Conclusions Bacillus cereus infection can have a fulminant clinical course that may be complicated by massive intravascular hemolysis. This pathogen should be suspected in immunosuppressed patients who experience gastrointestinal symptoms and should not be precluded by the absence of fever, especially if steroids such as dexamethasone are being given. Exchange transfusion may be lifesaving in Bacillus cereus septicemia associated with massive hemolysis.

PURPOSE To reassess the clinical and biologic significance of myeloid-associated antigen expression in childhood acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS We prospectively studied 334 newly diagnosed cases of this disease, using a comprehensive panel of antibodies that represented five myeloid cluster groups (CD13, CD14, CD15, CD33, and CD65). Blast cells were tested for ETV6 and MLL rearrangement using Southern blot analysis. RESULTS CD13 was expressed in 13.7% of cases, CD14 in 1%, CD15 in 6.6%, CD33 in 16%, and CD65 in 9.7%. Approximately one third of cases (31.4%) expressed one or more of these antigens (B-cell precursor, 31.9%; T-cell, 28.8%), while 10.5% expressed two or more (B-cell precursor, 11.3%; T-cell, 6.1%). Among the B-cell precursor leukemias, myeloid-associated antigen expression was significantly associated with a lack of hyperdiploidy and rearrangements of ETV6 or MLL gene. Most of the cases with MLL rearrangements (82%) expressed CD65, CD15, and CD33, either alone or in combination, whereas 48% of those with a rearranged ETV6 gene expressed CD13, CD33, or both. Myeloid-associated antigen expression did not correlate with event-free survival, whether the analysis was based on any of the five antigens in our panel or on the three more commonly tested antigens (CD13, CD33, and CD65). Importantly, this finding was not affected by exclusion of patients with ETV6 or MLL gene rearrangements. CONCLUSION Even though blast cell expression of myeloid-associated antigen expression shows significant associations with specific genetic abnormalities, it lacks prognostic value in childhood ALL.

PURPOSE To evaluate the incidence of and potential risk factors for second malignant neoplasms of the brain following treatment for childhood acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS The study population consisted of 1,612 consecutively enrolled protocol patients treated on sequential institutional protocols for newly diagnosed ALL at St Jude Children's Research Hospital (SJCRH) between 1967 and 1988. The median follow-up duration is 15.9 years (range, 5.5 to 29.9 y). RESULTS The cumulative incidence of brain tumors at 20 years is 1.39% (95% confidence interval [CI], 0.63% to 2.15%). Twenty-two brain tumors (10 high-grade gliomas, one low-grade glioma, and 11 meningiomas) were diagnosed among 21 patients after a median latency of 12.6 years (high-grade gliomas, 9.1 years; meningiomas, 19 years). Tumor type was linked to outcome, with patients who developed high-grade tumors doing poorly and those who developed low-grade tumors doing well. Risk factors for developing any secondary brain tumor included the presence of CNS leukemia at diagnosis, treatment on Total X therapy, and the use of cranial irradiation, which was dose-dependent. Age less than 6 years was associated with an increased risk of developing a high-grade glioma. CONCLUSION This single-institution study, with a high rate of long-term data capture, demonstrated that brain tumors are a rare, late complication of therapy for ALL. We report many more low-grade tumors than others probably because of exhaustive long-term follow-up evaluation. The importance of limiting cranial radiation is underscored by the dose-dependent tumorigenic effect of radiation therapy seen in this study.

The purpose of this study was to determine the incidence of and pharmacokinetic parameters associated with the development of transient encephalopathy following the administration of high-dose methotrexate and intrathecal chemotherapy in children with acute lymphoblastic leukemia (ALL). Two hundred and fifty-nine children with newly diagnosed ALL treated on one of two consecutive trials were analyzed. Presenting features in patients who developed transient encephalopathy were compared with those of patients who did not experience this event. For each patient who developed transient encephalopathy, methotrexate pharmacokinetic parameters were compared with those of matched controls. The cumulative incidence of acute encephalopathy was 3% (SE 1%) at 1 year and was associated with age greater than or equal to 10 years at diagnosis. Pharmacokinetic data did not differ between patients who developed transient encephalopathy and those who did not. The majority of patients had no long-term sequelae and were able to receive further courses of methotrexate without modification. Transient focal neurologic deficits occur in about 3% of children with ALL following the administration of intravenous and intrathecal methotrexate. These events cannot be predicted by pharmacokinetic parameters Of methotrexate disposition. However, these events are generally benign, suggesting that patients who experience acute encephalopathy should continue to receive this important chemotherapeutic agent.

Central nervous system (CNS) relapse has been an obstacle to uniformly successful treatment of childhood acute lymphoblastic leukemia (ALL) for many years. We therefore intensified intrathecal chemotherapy (simultaneously administered methotrexate, hydrocortisone, and cytarabine) for 165 consecutive children with newly diagnosed ALL enrolled in Total Therapy Study XIIIA from December 1991 to August 1994. The 64 patients (39%) who had 1 or more blast cells in cytocentrifuged preparations of cerebrospinal fluid at diagnosis, with or without associated higher-risk features, received additional doses of intrathecal chemotherapy during remission induction and the first year of continuation treatment. Patients with higher-risk leukemia, regardless of cerebrospinal fluid findings, also received additional doses of intrathecal chemotherapy during the first year of continuation treatment. Cranial irradiation was reserved for patients with higher-risk leukemia (22% of the total). The 5-year cumulative risk of an isolated CNS relapse among all 165 patients was 1.2% (95% confidence interval, 0% to 2.9%), whereas that of any CNS relapse was 3.2% (0.4% to 6.0%). The probability of surviving for 5 years without an adverse event of any type was 80.2% ± 9.2% (SE). Our results suggest that early intensification of intrathecal chemotherapy will reduce the risk of CNS relapse to a very low level in children with ALL, securing a higher event-free survival rate overall.

Although abnormalities involving the short arm of chromosome 12 (12p) are one of the most frequently observed rearrangements in childhood acute lymphoblastic leukemia (ALL), little is known about the frequency of different structural abnormalities and their relationship to the status of the ETV6 (also named TEL) gene in this region. Of 815 children with newly diagnosed ALL, 94 (11.5%) had a total of 104 cytogenetic 12p abnormalities. Loss of genetic material was observed in 67 (64%) of these abnormalities. Cases with 12p alterations had a much lower frequency of hyperdiploidy greater than 50 (7%) than did the ALL population in general, but these cases had a similar distribution of immunophenotype and similar 5-year event-free survival (70% ± 5% SE v 64% ± 2%, P = .64). Rearrangement of the ETV6 gene was identified in 36 (56%) of 64 cases evaluated. The ETV6-CBFA2 (TEL-AML1) fusion transcript was found in 25 (66%) of 38 cases evaluated, and all but one of these showed ETV6 rearrangement. Importantly, ETV6 rearrangement was associated with a favorable prognosis (5-year event-free survival: 89% ± 6% v 60% ± 1%, P < .01). We conclude that most but not all 12p cytogenetic abnormalities in childhood ALL involve ETV6, and that rearrangement of ETV6 is associated with a favorable treatment outcome.

Recombinant human granulocyte colony-stimulating factor PO1 CA-20180ilgrastim) hastens the recovery from neutropenia after P30 CA-21765emotherapy, but its role in the management of childhood leukemia is unclear.We randomly assigned 164 patients with acute lymphoblastic leukemia (age range, 2 months to 17 years) to receive placebo or G-CSF (10 microg per kilogram of body weight per day subcutaneously), beginning one day after the completion of remission-induction therapy and continuing until the neutrophil count was greater than or equal to 1000 per cubic millimeter for two days. The clinical and laboratory effects of this therapy were documented for 21 days. The area under the plasma G-CSF concentration-time curve was measured on days 1 and 7 in both groups.Responses to the growth factor could be assessed in 148 patients (73 in the G-CSF group and 75 in the placebo group). G-CSF treatment did not significantly lower the rate of hospitalization for febrile neutropenia (58 percent in the G-CSF group vs. 68 percent in the placebo group; relative risk, 0.85; 95 percent confidence interval, 0.59 to 1.16), increase the likelihood of event-free survival at three years (83 percent in both groups), or decrease the number of severe infections (five in the G-CSF group vs. six in the placebo group). Patients treated with G-CSF had shorter median hospital stays (6 days vs. 10 days, P=0.011) and fewer documented infections (12 vs. 27, P=0.009). The median total costs of supportive care were similar in the G-CSF and placebo groups ($8,768 and $8,616, respectively). Among patients who did not have febrile neutropenia during the first week of G-CSF or placebo injections, higher systemic exposure to the growth factor on day 7 was significantly related to a lower probability of subsequent hospitalization (P=0.049).G-CSF treatment had some clinical benefit in children who received induction chemotherapy for acute lymphoblastic leukemia, but it did not reduce the rate of hospitalization for febrile neutropenia, prolong survival, or reduce the cost of supportive care.

Background Pediatric oncology nurses in low- and middle-income countries have limited access to specialized education and clinical training. This is a major impediment for treating children with cancer and contributes to the disparity in survival rates between high- and low-income countries. The International Outreach Nursing Program at St Jude Children's Research Hospital established full-time nurse educator positions at partner sites throughout Latin America. Experienced nurses were hired as educators; however, they had no formal pediatric oncology education, limited teaching experience, and no mentors as this was a new nursing role in low- and middle-income countries. Objective Our objective was to create a regional education center to prepare nurse educators to succeed in this pioneering role. Interventions The Latin American Center for Pediatric Oncology Nursing Education was created at Calvo Mackenna Hospital in Santiago, Chile, to provide education, resources, and support to educators. Education resources, including a comprehensive orientation program and courses in chemotherapy and central venous line care, were developed. A 4-week on-site comprehensive educator course and an organized support system were implemented. Results Education, resources, and support have been provided to 13 nurse educators representing 7 Latin American countries. The educators have provided pediatric oncology education to more than 1000 nurses. Conclusions The center promotes excellence in pediatric oncology nursing by preparing and supporting educators, who in turn educate the entire nursing staff at partner sites. Implications for practice Nurse educators equipped with knowledge and skills can improve the quality of care and ultimately survival of patients throughout Latin America.

Mycobacterium leprae is a pathogenic bacteria that causes leprosy, a disease which affects mainly the skin, peripherical nerves, eyes and mucosa of the upper respiratory tract. Despite significant progress recorded in the last few years to stop this disease through a Multi-Drug Therapy (MDT) strategy, every year there are new reported cases of the disease. According to the World Health Organization, there were 192,242 new cases at the beginning of 2011. Mycobacterium leprae cannot be cultured in the laboratory but can be grown in mouse foot pads and more recently in nine banded armadillos because of its susceptibility to leprosy. Its highly reduced genome makes it an interesting species as a model for reductive evolution within the mycobacterial genus; it shares the same ancestor with Mycobacterium tuberculosis (MTB). A functional network for MTB was generated previously and extensive computational analyses were conducted to reveal the biological organization of the organism on the basis of the network’s topological properties. Here, we use genomic sequences and functional data from public databases to build protein functional networks for another slow grower, Mycobacterium leprae (MLP) and the fast growing non-pathogenic Mycobacterium smegmatis (MSM). Together with the MTB network, this provides an opportunity for comparison of three mycobacteria with different sized genomes. In this paper, we use network centrality measures to systematically compare MTB, MLP and MSM to quantify differences between these organisms at the systems biology level and to study network biology and evolution.

Tuberculosis (TB) caused by the intracellular pathogen Mycobacterium tuberculosis (MTB) continues to threaten public health globally. Considering the wide emergence of drug resistant MTB strains, particularly Multi-Drug Resistant (MDR-) and extensive Drug-Resistant (XDR-) TB, achieving the STOP-TB goal by 2050 remains questionable and challenging. One of the principal components in eradicating and eliminating TB and guaranteeing global TB control is the development of new treatment and prevention tools, including drugs and vaccines. The first and crucial step of this process is the identification of targets within the bacterial pathogen, which is driven by understanding the complex interplay between pathogen and host, as these interactions are key factors in determining the outcome of the MTB infection. We generated MTB and host (human) intra-species and the host-pathogen inter-species functional interaction networks using genomic and functional data retrieved from high-throughput experiments. In previous work, the MTB functional network was used to identify 881 proteins potential drug targets within this organism which provided the opportunity to expand the range of existing drug targets. Here we are using the functional interplay between host and pathogen to filter and prioritize the set of targets. This yields a filtered set of targets which also consider the host system and effects on host-pathogen interactions by leaving out proteins predicted to interact with human proteins. Further functional and statistical analyses were conducted in which uncharacterized proteins and those with paralogs were removed, resulting in a reduced list of protein targets with essential functions and no functional connections with human proteins.

BACKGROUND The impact of overt testicular disease on survival was assessed among patients treated at the study institution for childhood acute lymphoblastic leukemia (ALL) over a 15-year period. To the authors' knowledge, the frequency of overt testicular involvement at diagnosis of ALL and its impact on treatment outcome have not been reported previously. METHODS The medical records of all 651 boys with ALL enrolled on St. Jude Total Therapy Studies X-XIIIA (May 1979 to December 1993) were reviewed to determine the frequency of overt testicular involvement at diagnosis. The log rank test and sequential Cox regression analyses, adjusted for known adverse features, were used to compare event free and overall survival for patients with and without testicular leukemia. A matched-pairs analysis was then conducted for both outcome measures. RESULTS Thirteen of the 651 male patients (1.9%) presented with overt testicular leukemia. Compared with the other patients, these 13 boys had a significantly higher frequency of infant or adolescent age at diagnosis, hyperleukocytosis, splenomegaly, and mediastinal mass; a poorer 5-year event free survival (38% [95% confidence interval (CI), 15.4-61.4%] vs. 58% [95% CI, 53.6-61.7%], P = 0.06, log rank test); and a significantly poorer 5-year overall survival (37% [95% CI, 14-60.4%] vs. 75% [95% CI, 71.3-78.4%], P = 0.002). The difference in overall, but not event free, survival was supported by sequential Cox regression analyses and by the matched-pairs analysis (P = 0.04). CONCLUSIONS Overt testicular involvement with leukemia at diagnosis was associated with an adverse survival in boys with ALL. Testicular irradiation may not be necessary in those patients who present with overt testicular involvement. This finding merits prospective evaluation in a larger sample of similarly treated patients. Cancer 1996;78:2437-42.

Relapsed acute lymphoblastic leukemia (ALL) usually carries a dire prognosis. We evaluated the effectiveness and long-term complications of intensive rotational combination chemotherapy for late hematologic relapse (median, 16 months after elective cessation of therapy) among 34 children and young adults (ages 4 to 23 years). Concurrent central nervous system (CNS) relapse was present in 3 cases and testicular relapse in 4. Secondary therapy comprised an intensive five-drug reinduction (6 weeks) followed by continuation treatment with four drug pairs, rotated weekly in 4-week cycles over 120 weeks. Intrathecal chemotherapy (methotrexate, hydrocortisone, cytarabine) was given three times during reinduction and every 8 weeks during continuation. Treatment was electively discontinued at week 120 in the absence of detectable disease. Thirty-three patients (97%) attained a second complete remission. At a median follow-up of 9.3 years (range, 4.5 to 11.4), estimates of 5-year second event-free and overall survival (+/- SE) are 65% +/- 8% and 79% +/- 7%, respectively. Eleven patients had a second relapse (9 marrow, 2 testicular) and one developed secondary myeloid leukemia. There have been no CNS relapses or deaths in remission. Treatment was well-tolerated and was given largely on an outpatient basis. Late effects are primarily endocrinologic; one child had a second malignant solid tumor (presumed related to initial radiation therapy) that was treated successfully. Intensive treatment with alternating non-cross-resistant drug pairs for late hematologic relapses of ALL is effective and well-tolerated, and produces results similar to those achieved in patients with newly diagnosed ALL. Event- free survival compares favorably with reports of other relapse regimens, including those incorporating bone marrow transplantation.

A 4-year-old boy with acute lymphoblastic leukemia (ALL) whose leukemic cells contained at diagnosis a del(6q) had a different clone at relapse, characterized by an abnormal short arm of chromosome 12 (12p). Fluorescence in situ hybridization (FISH) analysis using a cosmid probe from the 12p12–13 region indicated a translocation of the 12p to another unknown chromosome of "G-group" size. Further analysis by dual chromosome painting confirmed the presence of a translocation, identified as t(12;21)(p13;q22). Previously reported cases showed this translocation at diagnosis of ALL, whereas this is the first case showing the specific t(12;21)(p13;q22) at relapse. This case study illustrates the value of FISH in resolving subtle recurrent chromosomal rearrangements that escape detection by routine cytogenetic analysis. Subsequent molecular evaluation of the patient's leukemic cells with the t(12;21) demonstrated a TEL/AML1 fusion protein.

MLL gene rearrangements are associated with an extremely poor prognosis in infants with acute lymphoblastic leukemia (ALL), but little is known about their clinical significance in older children. Therefore, we studied 45 cases of childhood ALL with abnormalities of chromosome 11q23 for rearrangement of the MLL gene to determine if this feature confers a uniformly poor prognosis. MLL gene rearrangements were detected in all 18 cases with the common t(4;11), t(9;11) or t(11;19) translocations, whereas only 5 of 12 patients with either unbalanced or uncommon balanced translocations demonstrated a rearrangement. Abnormalities of the MLL gene were not detected in any of the 15 cases with a deletion or inversion of the chromosomes 11q23 region. The presence of an MLL rearrangement was significantly associated with age less than 1 year (P < .001), leukocyte count –>50 x 10(9)/L (P = .003), and the absence of leukemic cell CD10 expression (P < .001). In a stratified statistical analysis adjusted for age and treatment protocol, MLL gene rearrangement was correlated with an inferior treatment outcome (P = .028). The 4-year event-free survival estimate (+/-SE) was 10% +/-6.5% for cases with a rearranged MLL gene and 64% +/-19.2% for other cases. When infants were excluded from the analysis, MLL rearrangement was still significantly associated with a poor outcome (P = .02), and remained so with the exclusion of t(4;11)-positive cases (P = .05). Thus, regardless of presenting age, MLL gene rearrangement identifies a high-risk subgroup of patients who are not likely to be cured with conventional treatment.

Early response to therapy, typically assessed by bone marrow status, is predictive of outcome in childhood acute lymphoblastic leukemia (ALL). Less is known about the significance of early clearance of blast cells in peripheral blood. We reviewed medical records of all patients with ALL enrolled on St Jude Total Therapy Study XI (February 1984 to September 1988) to determine the presence of blast cells in peripheral blood at diagnosis and after 1 week of intensive induction therapy. Of the 358 patients, 59 lacked evidence of circulating blast cells at diagnosis, and data were unavailable for 2 patients. The prognostic significance of persistent circulating blast cells in the remaining 297 patients was assessed in a multivariate analysis that included known adverse prognostic factors. Persistent circulating leukemic blasts were present at day 8 in 41 patients (14%). Compared with the “blast- negative” group, these patients had a significantly higher frequency of several adverse clinical features (leukocyte count > 50 x 10(9)/L, mediastinal mass, central nervous system leukemia, T-cell phenotype, lack of CD10 expression, and L2 morphology) and a significantly poorer 5-year event-free survival (34% +/- 8% [SE] v 77% +/- 3%, P < .01). By multivariate analysis, blast cell persistence at week 1 was the most significant adverse feature in the overall cohort (relative risk, 2.9; 95% confidence interval, 1.8 to 4.8) and in an analysis limited to B- lineage cases (relative risk, 3.6; 95% confidence interval, 1.9 to 7.1). Patients identified by this simple, noninvasive measure may benefit from early modification of therapy.

Purpose: A prospective assessment of neurocognitive performance was conducted in children with acute lymphoblastic leukemia (ALL) following isolated central nervous system (CNS) relapse to evaluate the impact of additional systemic/intrathecal (IT) chemotherapy and craniospinal irradiation (CSI) upon longterm intellectual function. Methods and Materials: Twenty-one children with ALL manifesting an isolated CNS relapse between 1984 through 1989 underwent serial evaluations of intellectual function. Neurocognitive function was measured by the full-scale intelligence quotient (FSIQ) as determined by the age-appropriate Wechsler Intelligence Scale and by achievement in reading, math, and spelling as assessed by the Wide Range Achievement Test (WRAT). Intelligence testing was initiated following isolated CNS relapse after clearance of cerebrospinal fluid (CSF) cytology but prior to CSI and continued at annual intervals for a minimum of 4 years postmeningeal failure. Protocol treatment for isolated CNS relapse consisted of reinduction and maintenance systemic therapy, intrathecal (IT) triple-agent chemotherapy, and early CSI (cranium to 24 Gy and spine to 15 Gy at 1.5 Gy/fraction) as outlined on the institutional «Total XI» trial. Results: All 21 children attained secondary CNS remission and underwent the planned additional systemic/IT chemotherapy and CSI. Fourteen of the 21 children remain in secondary continuous remission, while the remaining 7 experienced a second relapse and were removed from further neurocognitive assessment. For the eight female and six male long-term survivors, mean ages at original diagnosis and at CSI were 5.7 years (range=0.6-16.2) and 7.0 years (range=1.8-17.0), respectively. At a median follow-up interval of 4.6 years (ranges 1.7-6.8) post-CNS relapse, comparison of group mean initial to final FSIQs revealed no statistically significant difference between the two measures (94.5 vs. 95.9, respectively, n=11, p=0.52). None of the children are functioning in the mentally retarded range. Final FSIQ outcome directly correlated with initial FSIQ (p=0.00005, p=11), age at diagnosis (p=0.009, n=14), and age at CSI (p=0.011, n=14). In addition, change between initial and final FSIQ scores inversely correlated with age at diagnosis (p=0.009) and age at CSI (p=0.018) but not with baseline IQ score (p=0.41). Initial FSIQ scores were not influenced by either age at diagnosis (p=0.12) or age at CSI (p=0.14). Final group mean (range) WRAT scores in reading, math, and spelling were measured to be 94.7 (68-132), 95.6 (69-126), and 93.7 (77-122), respectively (n=13). Final reading and math scores directly correlated with both age at diagnosis (p=0.01) and age at CSI (p=0.009). Spelling outcome did not correlate with either age at diagnosis (p=0.25) or age at CSI (p=0.24). Nine children are placed in regular classrooms, while the remaining five require a mixed classroom environment. Conclusion: In our study, children with ALL experiencing an isolated CNS relapse tolerated additional systemic/IT chemotherapy and CSI without apparent deterioration of group serial intellectual scores. However, longitudinal analyses of group intellectual measures obscured the independent impact of initial FSIQ, age at original diagnosis, and age at CSI upon individual neurocognitive outcome. Early and more intensive psychoeducational stimulation may be needed in very young children presenting with low initial FSIQ scores who are treated with CSI and additional chemotherapy following isolated CNS relapse in ALL

PURPOSE To evaluate the immunophenotypes, karyotypes, and clinical features, including treatment responses, of patients with childhood acute lymphoblastic leukemia (ALL) and either a t(1;19)(q23;p13) or a der(19)t(1;19)(q23;p13) translocation. PATIENTS AND METHODS The lymphoblasts of 45 patients with a balanced translocation, t(1;19) or its derivative form, der(19)t(1;19), were analyzed by cytogenetic and immunologic methods for differences that might suggest distinct subtypes of ALL. This cohort was treated in four consecutive clinical trials with a median overall follow-up duration of 7 years. RESULTS A pre-B immunophenotype was found in 10 cases with the balanced t(1;19) and 31 with the unbalanced der(19)t(1;19). The four remaining cases, each with a derivative t(1;19), were classified as early pre-B ALL. The characteristic surface antigen profile of the 41 pre-B cases was CD19+/CD10+/CD22+/CD34-/CD20+/-, whether the translocation was balanced or derivative. In contrast to the four early pre-B cases, which had hyperdiploid karyotypes (> 50 chromosomes), the pre-B cases were primarily pseudodiploid. Comparison of presenting clinical and laboratory features, as well as event-free survival, failed to disclose any differences that would warrant separation of pre-B cases with a balanced or derivative translocation. However, neither subgroup responded to therapy as well as patients with early pre-B ALL, each of whom remains in complete remission for > or = 3 years. CONCLUSION The t(1;19) and the der(19)t(1;19) identify a relatively homogeneous group of patients with pre-B ALL, who can be expected to respond similarly to intensive chemotherapy. The exceptional cases have an early pre-B phenotype with hyperdiploid karyotypes and appear to have favorable prognosis.

High-dose methotrexate (HDMTX) is a component of most treatment protocols for childhood acute lymphoblastic leukemia (ALL), yet recent studies of receptor-mediated transport and saturable polyglutamylation have questioned its rationale. To investigate this in vivo, methotrexate and its active polyglutamated metabolites (MTX-PG) were measured in bone marrow blasts obtained from 101 children randomized to single-agent therapy with either HDMTX (1 g/m2 per 24 h i.v., n = 47) or low-dose MTX (LDMTX, 30 mg/m2 by mouth every 6 h x 6, n = 54), before remission induction therapy. Blast concentrations of total MTX-PGs (median 460 vs 1380 pmol/10(9) cells) and of long-chain MTX-glu4-6 were both significantly higher after HDMTX (P < 0.001). With either treatment, MTX-PGs were significantly higher in B-lineage blasts than in T-lineage blasts (LDMTX P = 0.001, HDMTX P = 0.03). In a multiple regression analysis of B-lineage ALL, blast MTX-PG was significantly related to MTX dose (or plasma MTX concentration), lymphoblast ploidy (hyperdiploid > nonhyperdiploid), and percentage S-phase. This is the first evidence that HDMTX achieves higher MTX-PG concentrations in ALL blasts in vivo, establishing a rationale for HDMTX in the treatment of childhood ALL, especially T-lineage or nonhyperdiploid B-lineage ALL, disease characteristics associated with a poor prognosis on conventional therapy.