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Biomedical subjects

R Willemze

Publications and source records attributed to R Willemze.

At least 163 records · Page 9Linked to original sources

Leukemia inhibitory factor induces in vivo expansion of bone marrow progenitor cells that accelerate hematopoietic reconstitution but do not enhance radioprotection in lethally irradiated mice.

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine with distinct hematopoietic activities. In vivo treatment of mice with recombinant murine LIF induces thrombocytosis and increases the number of hematopoietic progenitor cells (HPCs) in spleen and bone marrow (BM). In this study, we applied LIF to expand HPCs in vivo prior to syngeneic BM transplantation. BALB/c donor mice were treated with recombinant human LIF at a dose of 2.5 microg/day s.c. for seven days. This resulted in a 1.6-fold increment in platelet counts from 941 to 1,470 x 10(9)/l (mean, n = 20). Mean spleen weight increased from 120 mg to 160 mg (n = 5). The total numbers of HPCs in the spleen as well as in the BM, as assessed in a CFU-GM (colony forming unit-granulocyte-macrophage) assay, were significantly higher in LIF-treated donors than in saline-treated controls (30.1 +/- 14.5 versus 7.4 +/- 5.3 x 10(3) per spleen; mean +/- SD, n = 22,p < 0.001 and 74.4 +/- 17.1 versus 55.3 +/- 16.1 x 10(3) per femur, p < 0.001). Recipient mice were lethally (8.5 Gy) irradiated and transplanted with 3 x 10(5) BM cells derived from LIF- or saline-treated donors. Hematopoietic reconstitution was monitored by tail bleeding at three-day intervals. Platelet and WBC nadir counts in control animals were reached at day 9 (31 +/- 25 x 10(9)/l for platelets and 0.40 +/- 0.10 x 10(9)/l for WBC; mean +/- SD, n = 29 per treatment group); in animals transplanted with LIF-treated BM cells, these counts were 44 +/- 25 x 10(9)/l for platelets, p < 0.05 and 0.60 +/- 0.38 x 10(9)/l for WBC, p < 0.01. In addition, platelet reconstitution was faster in recipients of LIF-treated BM cells (226 +/- 118 versus 126 +/- 62 x 10(9)/l at day 12 and 633 +/- 174 versus 434 +/- 180 x 10(9)/l at day 15, p < 0.001). Similarly, the reconstitution of WBC was also significantly enhanced. The radioprotection rate of lethally irradiated recipients with increasing cell doses of BM cells derived from LIF-treated donors was higher at all cell doses tested then of control animals, but did not reach statistical significance. These results show that in vivo treatment with LIF expands the number of committed progenitor cells and BM repopulating cells that accelerate short-term hematopoietic reconstitution without increasing radioprotection. Our data do not support a major role for LIF as a single factor inducing expansion of hematopoietic stem cells in vivo.

Animals↗

Differential short-term and long-term repopulating ability of stem cell subsets in mice.

Hematopoietic reconsitution after transplantation requires the presence of cells with early and late repopulating ability. To determine the contribution of relatively immature and mature hematopoietic progenitor cells in engraftment, we used a modified rhodamine staining procedure to purify populations of rhodamine 123 (Rho)bright, Rhodull and Rho- cells from mouse steady-state bone marrow. Following transplantation of these subsets of stem cells in lethally irradiated mice, marrow repopulating cells were mainly present in the small fraction of Rho- cells, indicating that hematopoietic stem cells have a relatively high expression of P-glycoprotein. Similar cell populations could be purified from cytokine-mobilized blood following treatment with cyclophosphamide and G-CSF. The Rho- cell population contained the majority of hematopoietic stem cells with in vivo marrow repopulating ability. In methylcellulose colony assays, the majority of the committed progenitor cells were present in Rhodull and Rhobright fractions. These results indicate that relatively primitive populations of hematopoietic stem cells that lack colony-forming capacity in vitro mediate the early phase of engraftment following syngeneic stem cell transplantation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Absence of mutations in the RET gene in acute myeloid leukemia.

Expression of the tyrosine kinase receptor RET has previously been detected in normal hematopoietic cells, and especially in cells of the myeloid lineage. Furthermore, RET was shown to be differentially expressed in acute myeloid leukemia (AML), a disease characterized by excessive cell growth and aberrant maturation of cells, with the highest levels of expression in leukemias with monocytic differentiation. RET is known to be expressed in cells from the excretory system and from the developing central and peripheral nervous system. Both activating and inactivating aberrations in the RET gene have been detected in disorders derived from these tissues. To investigate whether the differential expression is a primary defect in AML, the presence of RET alterations was scanned by Southern blot analysis on DNA of blasts obtained from 17 AML patients. However, no RET gene aberrations were found. Subsequently, denaturing gradient gel electrophoresis (DGGE) analysis was performed on the DNA of blasts from ten selected cases. All five variants detected turned out to represent neutral DNA polymorphisms, including a novel polymorphism in exon 14. Since we were unable to detect mutations of RET in AML, it is unlikely that it plays an important role in leukemogenesis.

Blotting, Southern↗

Pentoxifylline inhibits human T-cell adhesion to dermal endothelial cells.

Pentoxifylline (PTX), a methyl xanthine derivative with phosphodiesterase inhibitory activity, has been shown to have antiinflammatory effects. Previous studies have demonstrated that PTX can suppress TNF alpha production and function, and can inhibit the adhesion of neutrophils and monocytes to endothelial cells. In the present study, we sought to determine whether PTX also interferes with the adhesion of human peripheral blood T lymphocytes to cells of the human dermal endothelial cell line HMEC-1. Using a cell adhesion immunoassay, the effect of different doses of PTX (10(-5)-10(-2) M) on the binding of unactivated or PMA-activated T cells to unstimulated or TNF alpha-stimulated endothelial cells was investigated. In addition, blocking experiments with monoclonal antibodies against pairs of adhesion molecules known to be involved in endothelial cell/T-cell adhesion were performed. Unactivated T cells showed minimal adhesion to unstimulated endothelial cells. PMA-activated T cells showed an eightfold increased binding to TNF alpha-stimulated endothelial cells, which was found to be mediated largely by LFA-1/ICAM-1. PTX inhibited the binding of PMA-activated T cells to TNF alpha-stimulated endothelial cells in a dose-dependent manner. This inhibition was only found when PTX was present during the adhesion assay. A similar inhibition was found when PTX was replaced by isobutylmethylxanthine, another methyl xanthine derivative, or by a combination of two cAMP analogues. The results suggest that interference with T-cell/endothelial cell adhesion, which forms an essential step in the migration of T cells from the peripheral blood into sites of inflammation, may be another explanation for the beneficial effect of PTX in several inflammatory dermatoses.

Anti-Inflammatory Agents, Non-Steroidal↗

Relation between expression of adhesion molecules and clinical behavior in cutaneous follicle center cell lymphomas.

BACKGROUND: Primary cutaneous follicle center cell lymphomas (PCFCCLs) of the head or trunk have a much better prognosis than morphologically similar large-cell lymphomas on the legs or follicle center cell lymphomas involving the skin secondarily (SCFCCLs). Recent studies suggest a relation between the expression of adhesion molecules and clinical behavior of malignant B-cell lymphomas. OBJECTIVE: Our purpose was to investigate a potential relation between the expression of adhesion molecules and clinical behavior of these three prognostically different groups of cutaneous B-cell lymphomas. METHODS: Immunohistochemical studies with a selected panel of monoclonal antibodies against adhesion molecules were performed on 10 PCFCCLs on the head or trunk, five PCFCCLs of the legs, and seven SCFCCLs. Expression of adhesion molecules was correlated with clinical and follow-up data. RESULTS: PCFCCLs of the head and trunk expressed ICAM-1 (80%) and LFA-1 (50%) much more frequently than PCFCCLs of the legs (40% and 20%, respectively) and SCFCCLs (14% and 14%, respectively). VLA-4 was expressed in 60% of PCFCCLs of the legs, but not by the PCFCCLs of the head or trunk. Absence of both ICAM-1 and LFA-1 on the neoplastic B cells correlated with a poor prognosis (seven of nine patients died of systemic lymphoma). In contrast, none of the patients with expression of LFA-1 or ICAM-1 have died of lymphoma thus far. CONCLUSION: Our results suggest a relation between the expression of adhesion molecules and the differences in clinical behavior between different groups of primary and secondary cutaneous follicle center cell lymphomas.

Adult↗

Quality of life in patients with acute myelogenous leukemia in prolonged first complete remission after bone marrow transplantation (allogeneic or autologous) or chemotherapy: a cross-sectional study of the EORTC-GIMEMA AML 8A trial.

A cross-sectional study of quality of life (QOL) was performed in 98 patients in continued first complete remission (CR) for 1-7.4 years, after inclusion in the AML 8A trial which prospectively compared allogeneic bone marrow transplantation (AlloBMT), autologous BMT (ABMT) and intensive consolidation chemotherapy. Several significant differences between the three treatment groups were observed, on the basis of patient self-reports, with regard to somatic symptoms (mouth sores, cough, hair loss, headache), repeated acute medical problems, physical functioning, role functioning, leisure activities and, above all, sexual functioning. There were also significant differences for overall physical condition, and overall quality of life. For all these parameters, the ranking was uniformly AlloBMT lower than ABMT lower than chemotherapy. These differences remain significant after adjustment for time interval between CR and QOL evaluation, sex or age. These results, confirming a higher risk of permanent impairment of QOL after BMT, may have an impact on medical decisions and warrant further studies.

Adult↗

Problems and possible solutions in finding an unrelated bone marrow donor. Results of consecutive searches for 240 Dutch patients.

To evaluate the efficiency of our protocol for finding an HLA matched unrelated bone marrow donor, search results obtained between 1990 and 1995 for 240 Dutch patients were analyzed. The percentage of patients for whom, according to information given by the registries, a fully split-HLA antigen matched donor is available, increased from 24% in 1990 to over 70% in 1995. As a result the percentage of patients transplanted rose from about 24% in 1990-1991 to 44% in 1994-1995. The median time between the start of the search and transplantation was about 6 months. The systematic use of Bone Marrow Donors Worldwide (BMDW) which comprises the HLA groups of all volunteer bone marrow donors in Europe, Israel, South Africa, North America, Canada, India, Australia and New Zealand has been essential in this context. While searching for a suitable donor several problems were encountered such as unavailability of donors (12%) and discordant typing results (8%; range < 1% to > 25%). Thus it is advisable to select several donors for a patient. For 86% of patients with at least one HLA identical donor on the serological level for HLA-A,-B,-DR,-DQ, an HLA-DRB1/3/4/5, and -DQB1 identical donor could be identified. As expected, patients with two frequent haplotypes in strong linkage disequilibrium had the best chance of obtaining an HLA matched donor. Unexpectedly, patients with only one such haplotype had an almost similar chance. It could be calculated that HLA-DR typing of HLA-A,-B identical donors was rarely cost-effective after 1992. Only 12 of the 75 transplanted patients (16%) typeable at DNA level for class II, turned out to be completely matched for HLA-A,-B,-C,-DRB1/3/4/5,-DQB1,-DPB1 and had a negative MLC test. In the group of patients transplanted with a fully matched donor and for whom a CTLp test was performed, only 7% (4/54) of the tests were negative. Search results for patients of non-European origin were dismal, with only four of 26 patients referred being transplanted. In summary, of the 240 patients for whom the Europdonor office searched for a donor, about one-third were transplanted, one-third had a potential donor but did not reach transplantation, while for the remaining one-third of patients no suitable donor could be found.

Adult↗

TCR gamma delta+ cells expressing Vgamma 9V delta2, which normally predominate the blood, are found in the spleens of patients with hairy cell leukemia.

T cell receptor gamma delta+ (TCR gamma delta+) cells are present in all lymphoid tissues, but at lower frequencies than TCR alpha beta+ cells. In normal spleens, they account for about 15-20% of CD3+ cells. In hairy cell leukemia (HCL), a B cell malignancy with a characteristic involvement of the spleen, splenic T cells of approximately 40% of the examined patients showed a remarkable increase in CD3+ TCR gamma delta+ cells. Therefore, we studied the TCR gamma delta phenotypes in blood and spleen of 12 HCL patients in comparison with normal samples. In normal blood (n= 6) the majority of TCR gamma delta+ cells expressed the Vgamma 9V delta2 phenotype, while in normal spleens (n = 9) a different population was found expressing Vdelta1. In contrast, six of eight paired blood and spleen samples of individual HCL patients demonstrated the same phenotype with predominantly Vgamma 9V delta2 expression. This change in splenic TCR gamma delta usage in patients with HCL might be the result of cell-trapping, or an infiltration of TCR gamma delta+ cells from the blood.

Humans↗

Allogeneic bone marrow transplantation for acute leukemia in patients over the age of 40 years. Acute Leukemia Working Party of the European Group for Bone Marrow Transplantation (EBMT).

Extension of allogeneic transplants to older patients has been limited by a high risk of transplant-related death and graft-versus-host disease. To evaluate the feasibility in older patients, a retrospective analysis of the procedure was performed for first remission acute leukemia in 192 patients aged over 40 years and compared with a group of 1119 recipients aged from 16 to 40 years reported to the EBMT from 1986 to 1992. Patient-, disease-, and treatment-related variables were compared between the two age groups using the chi2 statistical method for categorical variables. Variables differing significantly or recognized as potential prognostic factors were included in a multivariate analysis. Leukemia-free survival and relapse were comparable among the age groups in the two types of leukemias. Incidence of graft-versus-host disease was higher in the older group of ALL patients. Older patients with AML in first remission had a higher treatment-related mortality incidence, with no influence on survival. A pair-matched analysis of AML patients did not show any statistical difference in the probability of LFS, RI, TRM, and survival for the two age cohorts of patients. These results suggest that BMT should be considered for patients over 40 years of age.

Acute Disease↗

Mosaicism of the 5q deletion as assessed by interphase FISH is a common phenomenon in MDS and restricted to myeloid cells.

Interstitial deletion of chromosome 5q is a common cytogenetic abnormality observed in MDS. We have used fluorescence in situ hybridization (FISH) to determine accurately the percentage of cytogenetically abnormal peripheral blood cells. YAC and cosmid probes localized to chromosome 5q were hybridized to interphase nuclei from purified polymorphonuclear cells (PMNs) from six MDS patients with chromosome 5 deletions. Per patient, 25-67% of the cells exhibited one signal for the 5q31-q33 specific probes IL-4, D5S207 and c-fms. This percentage was constant for the various probes utilized for each patient. Hybridization of the same probes to PMNs from healthy individuals and hybridization of probes (D5S39 and D5S498) localized outside the deleted segments to PMNs of the patients, resulted in 90-95% nuclei with two signals. In addition, FACS-purified peripheral blood cells were investigated by FISH using the IL-4 cosmid. This demonstrated that the hybridization pattern in monocytes was similar to that observed in PMNs, whereas T-lymphocytes showed no loss of signals. These results indicate that a subfraction of the myeloid progenitor cells have acquired the 5q deletion.

Adult↗

T cells selectively infiltrate bone marrow areas with residual haemopoiesis of patients with acquired aplastic anaemia.

Aplastic anaemia (AA) is characterized by pancytopenia and bone marrow (BM) hypocellularity. In some patients AA may be mediated by T cells. To localize inflammatory cell infiltrates, we carried out a quantitative immunohistochemical analysis of BM biopsies of AA patients. In five out of eight biopsies, significantly higher numbers T cells were found in the areas with residual haemopoiesis (RH). The significantly increased numbers of CD3+ T cells in areas with RH supports the hypothesis of a site-directed infiltration and/or a local proliferation of T cells in the BM of patients with AA.

Anemia, Aplastic↗

Analysis of T-cell clonality in bone marrow of patients with acquired aplastic anaemia.

Acquired aplastic anaemia (AA) represents a state of bone marrow (BM) failure which is characterized by BM hypocellularity and pancytopenia. It has been hypothesized that in some AA patients, bone marrow failure is secondary to the targeted destruction of haemopoietic stem cells by autoreactive T cells. The response of T cells to antigenic stimulation has been shown, in a number of animal models and in autoimmune diseases, to result in the (oligo)clonal expansion of positively reacting T cells. For this reason, we studied the utilization of 24 T-cell receptor-variable gene segments (TCRBV) and the clonality in BM aspirates and peripheral blood (PB) of seven AA patients. BM from transplant donors served as controls. Determination of TCRBV gene segment usage revealed no significant differences between patients and controls. Clonality within each family was analysed by single-strand conformation polymorphism (SSCP) analysis. Clonal and clonally predominant bands were seen in BM of three AA patients in five to eight TCRBV families. Clonal rearrangements were encountered less often in BM of control subjects. In conclusion, our results suggest an antigen-driven T-cell response in the BM of predominantly AA patients resulting in oligoclonal T-cell outgrowth.

Adolescent↗

Human cytotoxic CD8+ T-lymphocyte clones engraft in severe combined immunodeficient (SCID) mice but show diminished function.

Mice with severe combined immunodeficiency (SCID) provide an in vivo model for studying interactions between human tumor cells and effector cells of the immune system. We studied the behavior of human alloreactive cytotoxic T lymphocytes (CTLs) in SCID mice, including the migration pattern of CD8+ or CD4+ CTL clones to various murine tissues, their engraftment in the absence or presence of recombinant human interleukin 2 (rhIL-2) compared with the engraftment of lymphokine activated killer (LAK) cells, and the in vitro as well as the in vivo function of the engrafted CTL clones. The polymerase chain technique using T-cell-receptor-gamma specific primers revealed the presence of human CD8+ CTL clones in the blood, lungs, and liver of mice receiving rhIL-2 for 14 days, for at least 18 days after intravenous inoculation. Human T cells were transiently detected in the bone marrow, lymph nodes, thymus, and spleen. Although the three CD8+ CTL clones and two CTL lines tested required rhIL-2 for their engraftment, the four LAK cell populations also engrafted in the absence of rhIL-2. In contrast to CD8+ T cells, only low frequencies (<1%) of CD4+ cells could be detected in the blood of the SCID mouse. Engrafted human T cells recovered from the murine blood showed absent or diminished cytotoxicity in vitro against human target cells in five or six experiments, respectively. In addition, when the antitumor activity of engrafted CD8+ clones was investigated in vivo using a xenotransplantation model of human B-cell lymphoma in SCID mice, no significant prolongation of the mean survival time of six treated animals was observed compared with animals treated with rhIL-2 alone. Our results illustrate that although in vitro primed and cultured human CD8+ T cells engraft in SCID mice, their in vitro and in vivo function is impaired.

Animals↗

Most primary cutaneous CD30-positive lymphoproliferative disorders have a CD4-positive cytotoxic T-cell phenotype.

Primary cutaneous CD30-positive (anaplastic) large T-cell lymphomas and lymphomatoid papulosis are closely related types of cutaneous T-cell lymphoma with a favorable prognosis. The neoplastic T cells in these conditions have the phenotype of activated CD3+, CD4+, CD8-, CD30+ skin homing T cells, but their normal counterpart has not yet been defined. To further characterize the cellular origin of the neoplastic T cells, skin biopsies from 14 patients with primary cutaneous CD30-positive (anaplastic) large T-cell lymphomas, nine patients with lymphomatoid papulosis, and six patients with primary cutaneous CD30-negative pleomorphic large T-cell lymphomas were stained with monoclonal antibodies against cytotoxic cell-associated molecules granzyme B and T-cell restricted intracellular antigen. In nine of nine lymphomatoid papulosis and in 10 of 14 CD30-positive primary cutaneous large T-cell lymphomas, expression of granzyme B and T-cell restricted intracellular antigen by variable numbers of neoplastic cells was found. Expression of granzyme B by the neoplastic CD30-positive T cells was confirmed by double-staining for granzyme B and CD30 (three cases) and by the detection of granzyme B mRNA using RNA in situ hybridization (one case). In most cases equal numbers of granzyme-B-positive and T-cell restricted intracellular antigen positive tumor cells were observed. In five of six CD30-negative primary cutaneous large T-cell lymphomas the neoplastic cells did not express these proteins, whereas in one case a sporadic positive tumor cell was found. These results demonstrate that, in contrast to primary cutaneous CD30-negative pleomorphic large T-cell lymphomas, the neoplastic cells in most primary cutaneous CD30-positive (anaplastic) large T-cell lymphomas and lymphomatoid papulosis have a unique CD4+, CD8-, cytotoxic T-cell phenotype.

CD4-Positive T-Lymphocytes↗

p53 and bcl-2 expression do not correlate with prognosis in primary cutaneous large T-cell lymphomas.

Overexpression of p53 protein in cutaneous T-cell lymphoma (CTCL) has been reported in primary cutaneous large T-cell lymphomas (PCLTCL) and has been associated with tumor progression and transformation in mycosis fungoides. However, the prognostic significance of p53 expression has not been studied thus far. In the present study we investigated the expression of p53 as well as bcl-2 protein in 27 PCLTCL, including 19 CD30-positive and 8 CD30-negative lymphomas, retrieved from the registry of the Dutch Cutaneous Lymphoma Working Group. The results were correlated with follow-up data and proliferative activity, as assessed by the percentage of MIB-1 positive tumor cells. Overexpression of p53 protein, defined as nuclear staining of more than 5% of the tumor cells, was found in 10 of 27 cases (37%), including 6 of 19 (32%) CD30+lymphomas and 4 of 8 (50%) CD30-PCLTCL. bcl-2 protein was expressed in 6 of 19 (32%) CD30+lymphomas and in only 1 of 8 (12%) CD30-PCLTCL. However, no significant correlation between p53 or bcl-2 expression and prognosis was found, neither in the whole group, nor within the CD30+ or CD30- group. In addition, no relationship between p53 expression and proliferative activity was found. The results confirm that p53 expression is more common in PCLTCL than in mycosis fungoides and Sézary syndrome. However, neither p53 nor bcl-2 expression correlated with survival or proliferative activity.

Adult↗

Cytotoxic T-lymphocyte (CTL) responses against acute or chronic myeloid leukemia.

In addition to chemotherapy and irradiation, in the context of allogeneic stem cell transplantation (SCT), the donor cell-mediated antileukemic effect can lead to sustained complete remissions, also in cases of a large tumor load. This phenomenon appears to be an immunologically mediated response, possibly due to various effector cell populations. Cytotoxic T-lymphocyte (CTL) responses against minor histocompatibility antigens with restricted tissue distribution, in particular restricted to some or all hematopoietic cells, may be highly efficient in inducing anti-leukemic responses for adoptive immunotherapy. Specific CTL responses against leukemia-associated antigens may be generated using leukemic cells modified to coexpress costimulatory molecules identical to professional antigen-presenting cells. Donor-derived T cells recognizing such antigens may be used in the context of allogeneic SCT to induce complete and sustained remissions, also in patients with leukemia refractory to chemotherapy. In these circumstances, the primary objective of allogeneic SCT may be not to diminish the number of malignant cells by the chemotherapy and irradiation as part of the conditioning regimen, but to allow immunotherapy against leukemic cells using donor lymphocyte populations.

Humans↗

Intensive postremission chemotherapy without maintenance therapy in adults with acute lymphoblastic leukemia. Dutch Hemato-Oncology Research Group.

PURPOSE: To investigate the value of intensive consolidation chemotherapy not followed by maintenance therapy in adult acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: A multicenter phase II trial was conducted in 130 adult patients with ALL between 16 and 60 years of age. After standard induction therapy, postinduction chemotherapy was given: three courses of high-dose cytarabine (2,000 mg/m2 every 12 hours for four doses) in combination with amsacrine (course one), mitoxantrone (course two), and etoposide (course three). CNS prophylaxis consisted of 10 injections of intrathecal methotrexate (IT MTX). Patients younger than 50 years with an HLA-identical sibling were eligible to receive allogeneic bone marrow transplantation (BMT). RESULTS: Ninety-five patients (73%) achieved complete remission (CR); 82% were younger than 50 years and 41% were older than 50 years. Seventeen patients (13%) were resistant to chemotherapy, and 18 (14%) died during induction treatment. Only age and performance status were significantly associated with response (P<.001 and .03, respectively). Death during consolidation occurred in four patients. The estimated 5-year overall survival (OS) was 22% for the entire group and 26% for patients younger than 35 years. Disease-free survival (DFS) at 5 years was 28% +/- 6 for patients younger than 35 years, 25% +/- 9 for patients between 35 and 50 years, and 0% for patients older than 50 years. Increasing age (P<.01) and expression of CD34 (P<.01) were adverse factors. Only three patients (3%) developed an isolated CNS relapse. CONCLUSION: Intensive consolidation including high-dose cytarabine not followed by maintenance therapy provides an outcome for adult patients with ALL that may be worse or even inferior compared with studies using long-term maintenance therapy. High-dose cytarabine in combination with IT MTX was effective for CNS prophylaxis.

Adolescent↗