Biomedical subjects

Martin Zimmermann

Publications and source records attributed to Martin Zimmermann.

At least 19 recordsLinked to original sources

PubMed2026

Blinatumomab for Replacing Chemotherapy in Pediatric Acute Lymphoblastic Leukemia.

BACKGROUND: Blinatumomab, a bispecific T-cell engager targeting the CD19 antigen on B cells, may offer an option to safely replace cycles of traditional chemotherapy in pediatric patients with newly diagnosed high-risk B-cell acute lymphoblastic leukemia (ALL). METHODS: We randomly assigned, in a 1:1 ratio, children with high-risk B-cell ALL to receive two cycles of blinatumomab (blinatumomab group) or two cycles of chemotherapy (control group) after consolidation. The primary end point was event-free survival as evaluated in a time-to-event analysis; the duration of event-free survival was defined as the time from randomization to the first event among resistance to protocol treatment, relapse, second cancer, or death from any cause. Our primary objective was to evaluate whether the 4-year event-free survival would be 10 percentage points higher in the blinatumomab group than in the control group. RESULTS: Overall, 709 of 768 eligible patients (92.3%) underwent randomization; 358 were assigned to the blinatumomab group and 351 to the control group. A planned interim analysis at a median follow-up of 2.9 years showed an estimated 4-year event-free survival of 83.0% (95% confidence interval [CI], 77.4 to 87.4) in the blinatumomab group and 70.3% (95% CI, 63.8 to 75.9) in the control group (P = 0.0002 in an intention-to-treat analysis). The estimated hazard ratio for a primary end-point event (blinatumomab vs. control) was 0.51 (95% CI, 0.35 to 0.73) as assessed with a Cox model. Infection related to the trial treatment occurred in 23.9% of patients in the blinatumomab group and in 69.4% of those in the control group (P<0.001). Life-threatening adverse events occurred in 2 patients (0.5%) in the blinatumomab group, including one (in 0.3%) that was fatal, and in 16 patients (4.7%) in the control group. Neurotoxic events were reported in 12.0% and 3.2%, respectively (P<0.001). Cytokine release syndrome of grade 2 or higher occurred in 1.1% of patients in the blinatumomab group. CONCLUSIONS: In children with newly diagnosed high-risk B-cell ALL, replacement of two cycles of highly toxic conventional chemotherapy with blinatumomab resulted in a significantly greater percentage of patients with event-free survival at 4 years. (Funded by Deutsche Krebshilfe and others; AIEOP-BFM ALL 2017 EudraCT number, 2016-001935-12; EU Clinical Trials number, 2023-509856-32-00; and ClinicalTrials.gov number, NCT03643276.).

Adolescent↗

PubMed2007

Non-hematopoietic stem cell transplantation treatment of juvenile myelomonocytic leukemia: a retrospective analysis and definition of response criteria.

BACKGROUND: Juvenile myelomonocytic leukemia (JMML) is a rare myeloproliferative disease of infancy. Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative treatment modality, while the role of anti-leukemic therapy prior to HSCT is uncertain. A comparative evaluation of the efficacy of different clinical protocols and great variety of anti-neoplastic drugs applied pre-HSCT is hampered by the lack of uniform criteria of response. Classification schemas applied in other forms of leukemia are of little value, because in JMML therapy may result in divergent responses in solid organs compared to peripheral blood (PB). PROCEDURE: We therefore defined separate response criteria for white blood count (WBC), platelet count, liver size, and spleen size. We then retrospectively evaluated the efficacy of 129 treatment courses other than HSCT administered to 63 children with JMML. Treatment consisted of intensive therapy according to AML-type chemotherapy, maintenance-type combination therapy, and single agent therapy. To account for the variability observed in the natural course of disease, we also evaluated 32 episodes of "no therapy." RESULTS: Best responses within 3 months of initiation of therapy were highly variable for the four response criteria. In contrast to platelet count and liver size, there was a significant correlation between WBC or spleen size and therapy. Response rates for WBC and spleen size were best for purine analogs, etoposide, and cytarabine as single agents or for maintenance-type combination therapy. CONCLUSION: To rigorously test future therapeutic strategies in this rare disease an international consensus on the definition of response criteria will be helpful.

Antineoplastic Agents↗

PubMed2007

Longitudinal evaluation of early and late anthracycline cardiotoxicity in children with AML.

BACKGROUND: Anthracyclines are effective antineoplastic drugs in acute myelogenous leukemia (AML). However, their use is limited by cardiomyopathy, which occurs in children already at cumulative doses of 300 mg/m(2) (given as daunorubicin equivalent). PROCEDURE: To evaluate anthracycline-associated cardiomyopathy in pediatric AML-patients, the incidence of early and late (>1 year after intensive AML chemotherapy) clinical and subclinical cardiotoxicity was analyzed out of a total of 1,207 patients <18 years treated between 1993 and 2003 in trials AML-BFM93/98: 1,010 protocol patients with de novo AML, 121 with Down syndrome (DS)-AML, and 76 with secondary AML. The cumulative dose of anthracyclines was generally risk-adapted: 300-450 mg/m(2) using 1-4-hr infusions of anthracyclines with the assumed lowest cardiotoxic potential. Eight hundred eighty-five patients (73%) were eligible for the analysis of early and 547 (45%) of late cardiotoxicity (1,399 follow-up data). RESULTS: Thirty-eight patients (4.3%), including 3 DS-AML and 1 secondary AML, suffered from early cardiomyopathy. After 5 years, four patients showed temporarily or persistently a reduced shortening fraction, which led to death in one DS-AML patient. Including these 4 patients, late cardiomyopathy was seen in 16 patients (cumulative incidence after 11 years: 5% +/- 1%). Nine patients (2.5 +/- 1%) showed clinical symptoms, five of them had persistent abnormal shortening fraction. Late subclinical cardiomyopathy occurred temporarily in seven patients. Late clinical cardiomyopathy mainly affected patients with a second anthracycline therapy (secondary malignancy) and those with early cardiotoxicity. CONCLUSION: In spite of a highly intensive and effective treatment, the frequency of anthracycline-associated cardiomyopathy was low in the AML-BFM studies.

Acute Disease↗

PubMed2007

Pulses of vincristine and dexamethasone in addition to intensive chemotherapy for children with intermediate-risk acute lymphoblastic leukaemia: a multicentre randomised trial.

BACKGROUND: Studies in the 1970s and 1980s suggested that the outcome of childhood acute lymphoblastic leukaemia (ALL) could be improved by intensification of conventional continuation chemotherapy with pulses of vincristine sulfate and steroids. We aimed to investigate the efficacy and toxic effects of vincristine-dexamethasone pulses as an addition to the continuation-therapy phase in a large cohort of children with intermediate-risk disease who were treated with the Berlin-Frankfurt-Münster (BFM) treatment strategy. METHODS: 3109 children, diagnosed with ALL and intermediate-risk features, were enrolled by eight participating organisations in eleven countries. All were treated with very similar protocols based on the BFM treatment strategy, which included induction, consolidation, reinduction, and continuation-therapy phases. At the beginning of the continuation-therapy phase, those patients in complete remission were randomly assigned to either a treatment or a control group. Control patients were given conventional mercaptopurine and methotrexate chemotherapy only. Patients in the treatment arm were also given pulses of vincristine (1.5 mg/m2 weekly for 2 weeks) and dexamethasone (6 mg/m2 daily for 7 days) every 10 weeks for six cycles. The primary outcome measure was disease-free survival. Analysis was by intention to treat. The study is registered at http://www.clinicaltrials.gov with the identifier NCT00411541. FINDINGS: 174 patients (5.6%) relapsed or died in complete remission before randomisation. Of the remaining 2935 patients, 2618 (89.2%) were randomly assigned: 1325 to the treatment group and 1293 to the control group. With median follow-up of 4.8 years, 240 children in the treatment group and 241 in the control group had relapses; 15 in the treatment group and 14 controls died in complete remission or developed second malignant neoplasms. The 5-year and 7-year disease-free survival estimates were 79.8% (SE 1.2) and 77.5% (1.5) in the treatment group and 79.2% (1.2) and 78.4% (1.3) in the control group, respectively. Treatment with pulses of vincristine and dexamethasone was associated with a non-significant 3% relative-risk reduction (hazard ratio 0.97; 95% CI 0.81-1.15; p=0.70). INTERPRETATION: Children with intermediate-risk ALL who received intensive chemotherapy based on BFM protocols did not benefit from intensification of the continuation-therapy phase with a schedule of pulses of vincristine and dexamethasone.

Adolescent↗

PubMed2007

Screening cell surface receptors using micromosaic immunoassays.

This report presents a general method for screening cell surface receptors using so-called micromosaic immunoassays. This method employs a microfluidic chip having n (n = 11) independent flow paths to move cells over m (m = 11) lines of surface-patterned antibodies for screening individual cells in a parallel, combinatorial, fast and flexible manner. The antibodies are patterned as 30-microm-wide lines on a poly(dimethylsiloxane) layer used to seal the area of the chip in which screening is being monitored. Mouse hybridoma cells having CD44 cell surface receptors and anti-CD44 antibodies were used to establish a proof-of-concept for this method. Both the capture antibodies and the cells were fluorescently labelled to allow the position of the cells to be accurately tracked over the binding sites using an inverted fluorescence microscope. The chips and cells were maintained at a constant temperature between 20 to 37 degrees C, and flow velocities of the cells over the capture areas were 100-280 microm s(-1), resulting in a approximately 0.1-0.3 s residency time of the cells on each of the eleven 30 x 30 microm s2 capture areas. Binding of the cells appeared to be specific to the capture areas, with a yield of 30% when the assay was performed at a temperature of 37 degrees C and with a slow flow velocity. We suggest that this proof-of-concept is broadly applicable to the screening of cells for medical/diagnostic purposes as well as for basic research on the interaction of cells with surfaces.

Animals↗

PubMed2006

Superiority of allogeneic hematopoietic stem-cell transplantation compared with chemotherapy alone in high-risk childhood T-cell acute lymphoblastic leukemia: results from ALL-BFM 90 and 95.

PURPOSE: The role of hematopoietic stem-cell transplantation (SCT) in first complete remission (CR1) for children with very high-risk (VHR) acute lymphoblastic leukemia (ALL) is still under critical discussion. PATIENTS AND METHODS: In the ALL-Berlin-Frankfurt-Münster (BFM) 90 and ALL-BFM 95 trials, 387 patients were eligible for SCT if there was a matched sibling donor (MSD). T-cell ALL (T-ALL) patients with poor in vivo response to initial treatment represented the largest homogeneous subgroup within VHR patients. RESULTS: Of 191 high-risk (HR) T-ALL patients, 179 patients (94%) achieved CR1. Twenty-three patients received an MSD-SCT. Furthermore, in trial ALL-BFM 95, eight matched unrelated donors (MUDs) and five mismatched family donors (MMFDs) were used. The median time to SCT was 5 months (range, 2.4 to 10.8 months) from diagnosis. The 5-year disease-free survival (DFS) was 67% +/- 8% for 36 patients who received an SCT in CR1 and 42% +/- 5% for the 120 patients treated with chemotherapy alone having an event-free survival time of at least the median time to transplantation (Mantel-Byar, P = .01). Overall survival (OS) rate for the SCT group was 67% +/- 8% at 5 years, whereas patients treated with chemotherapy alone had an OS rate of 47% +/- 5% at 5 years (Mantel-Byar, P = .01). Outcome of patients who received MSD-SCT versus MUD-/MMFD-SCT was comparable (DFS, 65% +/- 10% v 69% +/- 13%, respectively). However, relapses only occurred after MSD-SCT (eight of 23 patients), whereas treatment-related mortality only occurred after MUD-/MMFD-SCT (four of 13 patients). CONCLUSION: SCT in CR1 is superior to treatment with chemotherapy alone for childhood HR-T-ALL.

Adolescent↗

PubMed2006

Capillary pumps for autonomous capillary systems.

Autonomous capillary systems (CSs), where liquids are displaced by means of capillarity, are efficient, fast and convenient platforms for many bioanalytical applications. The proper functioning of these microfluidic devices requires displacing accurate volumes of liquids with precise flow rates. In this work, we show how to design capillary pumps for controlling the flow properties of CSs. The capillary pumps comprise microstructures of various shapes with dimensions from 15-250 microm, which are positioned in the capillary pumps to encode a desired capillary pressure. The capillary pumps are designed to have a small flow resistance and are preceded by a constricted microchannel, which acts as a flow resistance. Therefore, both the capillary pump and the flow resistance define the flow rate in the CS, and flow rates from 0.2-3.7 nL s(-1) were achieved. The placement and the shape of the microstructures in the capillary pumps are used to tailor the filling front of liquids in the capillary pumps to obtain a reliable filling behaviour and to minimize the risk of entrapping air. The filling front can, for example, be oriented vertically or tilted to the main axis of the capillary pump. We also show how capillary pumps having different hydrodynamic properties can be connected to program a sequence of slow and fast flow rates in a CS.

Journal Article↗

PubMed2006

Prophylactic human granulocyte colony-stimulating factor after induction therapy in pediatric acute myeloid leukemia.

Children with acute myelogenous leukemia (AML) have a high risk of infectious complications that might be reduced by prophylactic granulocyte colony-stimulating factor (G-CSF). However, G-CSF could induce AML blast proliferation. The prospective randomized trial AML-BFM 98 investigated the impact of G-CSF on hematopoetic recovery and infectious complications (primary endpoints) and on outcome (secondary endpoint) in children (aged 0-18 years) with de novo AML. Patients with more than 5% blasts in day-15 bone marrow or with FAB M3 were not included. Between 1998 and 2003, 161 children with AML were randomized to receive G-CSF after inductions 1 and 2, whereas 156 patients were assigned to the control group. Time of neutropenia after inductions 1 and 2 was significantly shorter in the G-CSF group (23 vs 18 days and 16 vs 11 days; P=.02 and=.001, respectively). G-CSF did not decrease the incidence of febrile neutropenia (72 and 36 patients vs 78 and 37 patients, respectively), microbiologically documented infections (27 and 25 patients vs 36 and 19 patients, respectively) and infection-associated mortality (5 vs 2 patients). Both groups had similar 5-year event-free survival (EFS; 59%+/-4% vs 58%+/-4%). Since G-CSF does not influence the risk of infectious complications or outcome in children undergoing therapy for AML, one cannot advocate the routine use of G-CSF in this patient group.

Adolescent↗

PubMed2006

Less toxicity by optimizing chemotherapy, but not by addition of granulocyte colony-stimulating factor in children and adolescents with acute myeloid leukemia: results of AML-BFM 98.

PURPOSE: To improve prognosis in children with acute myeloid leukemia (AML) by randomized comparisons of (1) two short consolidation cycles versus the Berlin-Frankfurt-Muenster (BFM) -type biphasic 6-week consolidation and (2) the prophylactic administration of granulocyte colony-stimulating factor (G-CSF) versus no G-CSF. Further, therapy for standard risk patients was intensified by addition of a second induction, HAM (high-dose cytarabine and mitoxantrone). PATIENTS AND METHODS: Four hundred seventy-three patients younger than 18 years with de novo AML were enrolled in trial AML-BFM 98. Patients received five courses of intensive chemotherapy, cranial irradiation, and 1-year maintenance therapy. RESULTS: Four hundred eighteen patients (88%) achieved remission. Compared with trial AML-BFM 93, early deaths decreased from 7.4 to 3.2% (P = .005), and 5-year overall survival increased from 58% to 62% (log-rank P = .03). Both types of consolidation therapy led to similar outcome (event-free survival, 51% v 50%), but in the two-cycle arm, treatment duration was shorter (median duration, 15 days), and treatment related mortality was lower (five v nine patients). G-CSF shortened neutropenia, but did not reduce the rate of severe infections. Intensification of induction therapy did not improve prognosis of standard-risk patients (event-free survival, 62% v 67%). CONCLUSION: Overall results were improved by neither the administration of G-CSF nor by cycle therapy; however, the latter was easier to perform. Compared with study AML-BFM 93, therapy intensification with HAM in standard-risk patients did not result in improved prognosis. Future treatment designs have to balance intensification of treatment with higher toxicity, improve supportive care, and to consider alternative treatment strategies.

Acute Disease↗

PubMed2006

Accumulation of cadmium ions in the methylotrophic yeast Hansenula polymorpha.

Intracellular cadmium (Cd(2+)) ion accumulation and the ability to produce specific Cd(2+) ion chelators was studied in the methylotrophic yeast Hansenula polymorpha. Only one type of Cd(2+) intracellular chelators, glutathione (GSH), was identified, which suggests that sequestration of this heavy metal in H. polymorpha occurs similarly to that found in Saccharomyces cerevisiae, but different to Schizosaccharomys pombe and Candida glabrata which both synthesize phytochelatins. Cd(2+) ion uptake in the H. polymorpha wild-type strains appeared to be an energy dependent process. It was found that Deltagsh2 mutants, impaired in the first step of GSH biosynthesis, are characterized by increase in net Cd(2+) ion uptake by the cells, whereas Deltagsh1/Deltamet1 and Deltaggt1 mutants impaired in sulfate assimilation and GSH catabolism, respectively, lost the ability to accumulate Cd(2+) intracellularly. Apparently H. polymorpha, similarly to S. cerevisiae, forms a Cd-GSH complex in the cytoplasm, which in turn regulates Cd(2+) uptake. Genes GSH1/MET1 and GGT1 are involved in maturation and metabolism of cellular Cd-GSH complex, respectively. Transport of [(3)H]N-ethylmaleimide-S-glutathione ([(3)H]NEM-SG) conjugate into crude membrane vesicules, purified from the wild-type cells of H. polymorpha appeared to be MgATP dependent, uncoupler insensitive and vanadate sensitive. We suggest that MgATP dependent transporter involved in Cd-GSH uptake in H. polymorpha, is similar to S. cerevisiae Ycf1-mediated vacuolar transporter responsible for accumulation of organic GS-conjugates and Cd-GSH complex.

Adenosine Triphosphate↗

PubMed2006

Residual disease monitoring in childhood acute myeloid leukemia by multiparameter flow cytometry: the MRD-AML-BFM Study Group.

PURPOSE: Monitoring of residual disease (RD) by flow cytometry in childhood acute myeloid leukemia (AML) may predict outcome. However, the optimal time points for investigation, the best antibody combinations, and most importantly, the clinical impact of RD analysis remain unclear. PATIENTS AND METHODS: Five hundred forty-two specimens of 150 children enrolled in the AML-Berlin-Frankfurt-Muenster (BFM) 98 study were analyzed by four-color immunophenotyping at up to four predefined time points during treatment. For each of the 12 leukemia-associated immunophenotypes and time points, a threshold level based on a previous retrospective analysis of another cohort of children with AML and on control bone marrows was determined. RESULTS: Regarding all four time points, there is a statistically significant difference in the 3-year event-free survival (EFS) in those children presenting with immunologically detectable blasts at 3 or more time points. The levels at bone marrow puncture (BMP) 1 and BMP2 turned out to have the most significant predictive value for 3-year-EFS: 71% +/- 6% versus 48% +/- 9%, P(Log-Rank) = .029 and 70% +/- 6% versus 50% +/- 7%, P(Log-Rank) = .033), resulting in a more than two-fold risk of relapse. In a multivariate analysis, using a combined risk classification based on morphologically determined blasts at BMP1 and BMP2, French-American-British classification, and cytogenetics, the influence of immunologically determined RD was no longer statistically significant. CONCLUSION: RD monitoring before second induction has the same predictive value as examining levels at four different time points during intensive chemotherapy. Compared with commonly defined risk factors in the AML-BFM studies, flow cytometry does not provide additional information for outcome prediction, but may be helpful to evaluate the remission status at day 28.

Adolescent↗

PubMed2006

MTHFR 677 (C-->T) polymorphism is not relevant for prognosis or therapy-associated toxicity in pediatric NHL: results from 484 patients of multicenter trial NHL-BFM 95.

We analyzed the relationship of genetic variation within the methylenetetrahydrofolate reductase gene (MTHFR 677 C-->T) with clinical characteristics, outcome, and therapy-related toxicity in pediatric non-Hodgkin's lymphoma (NHL) in our multicenter trial NHL-BFM 95. In this trial, high-dose methotrexate (MTX) infusion regimens were randomized (4- vs 24-h infusion) in patients with B-cell lymphoma; MTX was applied as 24-h infusion in all patients with lymphoblastic lymphoma and anaplastic large cell lymphoma. Toxicity data were collected per patient and therapy course according to National Cancer Institute Common Toxicity Criteria (NCI-CTC). The genotypes in 484 pediatric patients were distributed as follows: MTHFR 677 CC, 206 patients (42.6%); MTHFR 677 CT, 214 patients (44.2%); and MTHFR 677 TT, 64 patients (13.2%). Lymphoblastic lymphoma was significantly associated with homozygosity for the MTHFR 677 T allele. No association of MTHFR 677 genotype with clinical characteristics (sex, age, and tumor stage), outcome, or therapy-related toxicity could be detected. Therefore, we conclude that the MTHFR 677 C-->T polymorphism does not appear to influence outcome or therapy-associated toxicity in pediatric patients with NHL treated on BFM protocols.

Adolescent↗

PubMed2006

Impact of cranial radiotherapy on central nervous system prophylaxis in children and adolescents with central nervous system-negative stage III or IV lymphoblastic lymphoma.

PURPOSE: In the Non-Hodgkin's Lymphoma-Berlin-Frankfurt-Munster (NHL-BFM) 95 trial, we tested, against the historical control of the combined trials NHL-BFM90 and NHL-BFM86, whether prophylactic cranial radiotherapy (PCRT) can be omitted for CNS-negative patients with stage III or IV lymphoblastic lymphoma (LBL) with sufficient early response. PATIENTS AND METHODS: Apart from the removal of PCRT in NHL-BFM95, the chemotherapy of the three trials was identical except for the amount of l-asparaginase and daunorubicin during induction. The therapy in NHL-BFM95 was accepted to be noninferior when compared with trials NHL-BFM90/86 if the lower limit of the one-sided 95% CI for the difference in the 2-year probability of event-free-survival (pEFS) between target patients of NHL-BFM95 and the historical controls of NHL-BFM90/86 did not exceed -14%. The target patient group consisted of stage III and IV patients who were CNS negative and responded well to induction therapy. RESULTS: The number of target patients was 156 in NHL-BFM95 (median age, 8.6 years; range, 0.2 to 19.5 years) and 163 in NHL-BFM90/86 (median age, 8.4 years; range, 0.6 to 16.6 years). For the target group, the pEFS rates at 2 and 5 years were 86% +/- 3% and 82% +/- 3%, respectively, in NHL-BFM95 (median follow-up time, 5.1 years; range, 2.1 to 9.1 years) compared with 91% +/- 2% and 88% +/- 3%, respectively in NHL-BFM90/86 (median follow-up time, 10.7 years; range, 5 to 15.4 years). The lower limit of the one-sided 95% CI for the difference in pEFS was -11% at 2 years and -13% at 5 years. In NHL-BFM95, one isolated and two combined CNS relapses occurred compared with one combined CNS relapse in NHL-BFM90/86. Five-year disease-free-survival rate was 88% +/- 3% in NHL-BFM95 compared with 91% +/- 2% in NHL-BFM90/86. CONCLUSION: For CNS-negative patients with stage III or IV LBL and sufficient response to induction therapy, treatment without PCRT may be noninferior to treatment including PCRT.

Adolescent↗

PubMed2006

Diffuse large B-cell lymphoma in pediatric patients belongs predominantly to the germinal-center type B-cell lymphomas: a clinicopathologic analysis of cases included in the German BFM (Berlin-Frankfurt-Munster) Multicenter Trial.

Diffuse large B-cell lymphoma (DLBCL) in adults is a heterogeneous disease. Biologic subgroups of DLBCL with a favorable prognosis (germinal center B-cell-like, GCB) and with a poor prognosis (activated B-cell-like, ABC) have been defined by gene expression profiling and can be distinguished by immunohistochemistry. In contrast to their adult counterparts, children with DLBCL have an excellent prognosis. We analyzed 63 cases of DLBCL in pediatric patients by immunohistochemistry and fluorescence in situ hybridization (FISH) and found a striking predominance of a GCB subtype, which might explain the good clinical outcome in these lymphomas. Interestingly, FISH applied to 50 of these cases, as well as conventional cytogenetics available in 3 cases, revealed absence of the translocation t(14;18) involving the BCL2 gene, which is present in about 15% of adult GCB subtype DLBCL. Our data indicate that pediatric DLBCL differs from adult DLBCL and might comprise a biologically unique subgroup of DLBCL from which important insights into the pathogenesis and biology of this disease might be gained.

Child↗

PubMed2005

Tumor necrosis factor and lymphotoxin alfa genetic polymorphisms and outcome in pediatric patients with non-Hodgkin's lymphoma: results from Berlin-Frankfurt-Münster Trial NHL-BFM 95.

PURPOSE: To analyze the association of genetic variation within the tumor necrosis factor (TNF -308 [G-->A]) and lymphotoxin alfa (LT-a +252 [A-->G]) genes with outcome in non-Hodgkin's lymphoma of childhood and adolescence. PATIENTS AND METHODS: Genotyping of the TNF -308 (G-->A) and LT-a +252 (A-->G) polymorphisms in patients (n = 488) enrolled onto the German-Austrian-Swiss multicenter trial NHL-BFM 95 from April 1996 to January 2000 was performed by polymerase chain reaction with subsequent restriction fragment length polymorphism analysis on DNA from tumor-free specimen. RESULTS: In patients with Burkitt's lymphoma (BL) and B-cell acute lymphoblastic leukemia (B-ALL; n = 219, 211 eligible patients), patients carrying at least two variant alleles (high-producer haplotypes) had an increased risk of events: probability of event-free survival (pEFS) at 3 years was 81% (SE = 5%), compared with 91% (SE = 2%) in low-producer haplotypes (P = .018). In BL/B-ALL with high tumor load (lactate dehydrogenase [LDH] > or = 500 U/L; n = 104), pEFS was 69% (SE = 8%) in high-producer versus 85% (SE = 4%) in low-producer haplotypes (P = .05). In multivariate analysis including risk factors for events (LDH > or = 500 U/L, CNS involvement, methotrexate infusion regimen), TNF -308/LT-alpha +252 haplotype kept prognostic relevance: patients with high-producer haplotypes had a 2.34-fold increase in risk of events (P = .048). The TNF -308 (G-->A) and LT-alpha +252 (A-->G) polymorphisms were not associated with pEFS in lymphoblastic lymphoma (n = 101), anaplastic large-cell lymphoma (n = 67), or diffuse large B-cell lymphoma (n = 65), nor with therapy-related toxicity. CONCLUSION: The TNF -308 (G-->A) and LT-a +252 (A-->G) polymorphisms were negative prognostic factors in pediatric BL/B-ALL. Among patients with serum LDH > or = 500 U/L, haplotype analysis further determined patients at risk for events.

Adolescent↗

PubMed2005

Continuous flow in open microfluidics using controlled evaporation.

This paper presents a method for programming the flow rate of liquids inside open microfluidic networks (MFNs). A MFN comprises a number of independent flow paths, each of which starts with an open filling port, has a sealed microchannel in which assays can be performed, and an open capillary pump (CP). The MFN is placed over Peltier elements and its flow paths initially fill owing to capillary forces when liquids are added to the filling ports. A cooling Peltier element underneath the filling ports dynamically prevents evaporation in all filling ports using the ambient temperature and relative humidity as inputs. Another Peltier element underneath the CPs heats the pumps thereby inducing evaporation in the CPs and setting the flow rate in the microchannels. This method achieves flow rates in the microchannels ranging from approximately 1.2 nL s(-1) to approximately 30 pL s(-1), and is able to keep 90% of a 0.6 microL solution placed in an open filling port for 60 min. This simple and efficient method should be applicable to numerous assays or chemical reactions that require small and precise flow of liquids and reagents inside microfluidics.

Capillary Action↗

PubMed2005

Quality management for clinical trials within the German Competence Network Paediatric Oncology and Haematology.

The German 'Competence Network Paediatric Oncology and Haematology' aims at improving the structure of paediatric oncology and haematology as a whole, focussing in particular on the quality of clinical trials and study co-ordinating centres. This comprises the following measures: (1) Employment of research and trial assistants in order to improve the quality of documentation and study management in the participating hospitals. (2) Development of an internet portal to provide medical information for non-professionals, for patients and their families as well as for health professionals. (3) The project group 'Central Trial Support' supports study centres during the process of writing and examining new treatment protocols so that they are in compliance with the Good Clinical Practice criteria, formal criteria, legal requirements and statutory provisions. This group currently produces a structural standardisation of study protocols and case record forms in order to improve their usability. The 'Competence Network Malignant Lymphomas' is a project with similar aims and will be outlined for comparison.

Child↗

PubMed2005

Thiopurine methyltransferase (TPMT) genotype and early treatment response to mercaptopurine in childhood acute lymphoblastic leukemia.

CONTEXT: Early response to multiagent chemotherapy, including mercaptopurine, as measured by minimal residual disease is an important prognostic factor for children with acute lymphoblastic leukemia (ALL). Thiopurine methyltransferase (TPMT) is involved in the metabolism of mercaptopurine and subject to genetic polymorphism, with heterozygous individuals having intermediate and homozygous mutant individuals having very low TPMT activity. OBJECTIVE: To assess the association of TPMT genotype with minimal residual disease load before and after treatment with mercaptopurine in the early treatment course of childhood ALL. DESIGN, SETTING, AND PATIENTS: TPMT genotyping of childhood ALL patients (n = 814) in Germany consecutively enrolled in the ALL-BFM (Berlin-Frankfurt-Münster) 2000 study from October 1999 to September 2002. Minimal residual disease was analyzed on treatment days 33 and 78 for risk-adapted treatment stratification. A 4-week cycle of mercaptopurine was administered between these 2 minimal residual disease measurements. Patients (n = 4) homozygous for a mutant TPMT allele, and consequently deficient in TPMT activity, were treated with reduced doses of mercaptopurine and, therefore, not included in the analyses. MAIN OUTCOME MEASURES: Minimal residual disease load before (day 33) and after (day 78) mercaptopurine treatment. Loads smaller than 10(-4) were defined as negative. RESULTS: Patients (n = 55) heterozygous for allelic variants of TPMT conferring lower enzyme activity had a significantly lower rate of minimal residual disease positivity (9.1%) compared with patients (n = 755) with homozygous wild-type alleles (22.8%) on day 78 (P = .02). This translated into a 2.9-fold reduction in risk for patients with wild-type heterozygous alleles (relative risk, 0.34; 95% confidence interval, 0.13-0.86). CONCLUSIONS: TPMT genotype has a substantial impact on minimal residual disease after administration of mercaptopurine in the early course of childhood ALL, most likely through modulation of mercaptopurine dose intensity. Our findings support a role for minimal residual disease analyses in the assessment of genotype-phenotype associations in multiagent chemotherapeutic trials.

Adolescent↗