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Biomedical subjects

R Willemze

Publications and source records attributed to R Willemze.

At least 109 records · Page 6Linked to original sources

Pentostatin (Nipent) in T-cell malignancies. Leukemia Cooperative Group and the European Organization for Research and Treatment of Cancer.

Within this phase II trial of the European Organization for Research and Treatment of Cancer, we have investigated the safety and efficacy of pentostatin (Nipent; SuperGen, San Ramon, CA) in refractory lymphoid malignancies. Pentostatin was administered at a dosage of 4 mg/m2 every week for the first 3 weeks, then every 14 days, followed by maintenance therapy of 4 mg/m2 monthly for a maximum of 6 months. We have previously reported the results in T- and B-cell prolymphocytic leukemia, B-cell chronic lymphocytic leukemia, and hairy cell leukemia This report focuses on the outcome in T-cell malignancies: T-cell chronic lymphocytic leukemia, Sézary syndrome, mycosis fungoides, and T-zone lymphoma. Of 92 patients with these diagnoses enrolled, 76 were evaluable for response and toxicity, ie, 25 of 28 with T-cell chronic lymphocytic leukemia, 21 of 26 with Sézary syndrome, 22 of 26 with mycosis fungoides, and eight of 12 with T-zone lymphoma. All patients had progressive and advanced disease. Sixteen patients (21%) died during the first 9 weeks of treatment: 12 of progressive disease, two of infectious complications thought to be unrelated to treatment, one of myocardial infarction, and one of renal failure related to administration of intravenous contrast. Major toxicity (grades 3 and 4) included infection in 10.5% of patients, nausea/vomiting in 5%, and hepatotoxicity in 3%. One patient (1.3%) achieved a complete remission and 15 (19.7%) a partial remission. Better results were achieved in patients with Sézary syndrome or mycosis fungoides (complete remission + partial remission = 33.4% and 22.7%, respectively) than in patients with T-cell chronic lymphocytic leukemia (8%) or T-zone lymphoma (25%). We conclude that pentostatin is active in low-grade T-cell malignancies. Toxicities are mild to moderate at the dose schedule administered. Severe hematologic toxicity has not been observed. The efficacy at the present dose level is moderate. A higher dose might be necessary for some T-cell malignancies.

Adult↗

Prevention of interleukin-8-induced mobilization of hematopoietic progenitor cells in rhesus monkeys by inhibitory antibodies against the metalloproteinase gelatinase B (MMP-9).

Previously, we demonstrated that IL-8 induces rapid mobilization of hematopoietic progenitor cells (HPC) from the bone marrow of rhesus monkeys. Because activation of neutrophils by IL-8 induces the release of gelatinase B (MMP-9), which is involved in the degradation of extracellular matrix molecules, we hypothesized that MMP-9 release might induce stem cell mobilization by cleaving matrix molecules to which stem cells are attached. Rhesus monkeys were treated with a single i.v. injection of 0.1 mg/kg human IL-8, which resulted in a 10- to 100-fold increase in HPC within 30 min after injection. Zymographic analysis revealed a dramatic instantaneous increase in the plasma levels of MMP-9, followed by the increase in circulating HPC. Enzyme levels decreased at 2 h after injection of IL-8, simultaneously with the decrease in the numbers of circulating HPC. To test the hypothesis that MMP-9 induction was involved in HPC mobilization, rhesus monkeys were treated with a highly specific inhibitory monoclonal anti-gelatinase B antibody. Anti-gelatinase B at a dose of 1-2 mg/kg completely prevented the IL-8-induced mobilization of HPC, whereas a dose of 0.1 mg/kg had only a limited effect. Preinjection of inhibitory antibodies did not preclude the IL-8-induced production and secretion of MMP-9. Pretreatment with an irrelevant control antibody did not affect IL-8-induced mobilization, showing that the inhibition by the anti-gelatinase B antibody was specific. In summary, IL-8 induces the rapid systemic release of MMP-9 with concurrent mobilization of HPC that is prevented by pretreatment with an inhibitory anti-gelatinase B antibody, indicating that MMP-9 is involved as a mediator of the IL-8-induced mobilization of HPC.

Animals↗

Complete remission of accelerated phase chronic myeloid leukemia by treatment with leukemia-reactive cytotoxic T lymphocytes.

Relapse of chronic myeloid leukemia (CML) in chronic phase after allogeneic stem cell transplantation (SCT) can be successfully treated by donor lymphocyte infusion (DLI). However, relapse of accelerated phase CML, blast crisis, or acute leukemia after allogeneic SCT are resistant to DLI in the majority of cases. In vitro-selected and expanded leukemia-reactive T-cell lines may be more effective in inducing an antileukemic response in vivo. To treat a patient with accelerated phase CML after allogeneic SCT, leukemia-reactive cytotoxic T-lymphocyte (CTL) lines were generated from her HLA-identical donor. Using a modification of a limiting dilution assay, T cells were isolated from the donor, selected based on their ability to inhibit the in vitro growth of CML progenitor cells, and subsequently expanded in vitro to generate CTL lines. Three CTL lines were generated that lysed the leukemic cells from the patient and inhibited the growth of leukemic progenitor cells. The CTL did not react with lymphocytes from donor or recipient and did not affect donor hematopoietic progenitor cells. The 3 leukemia-reactive CTL lines were infused at 5-week intervals at a cumulative dose of 3.2 x 10(9) CTL. Shortly after the third infusion, complete eradication of the leukemic cells was observed, as shown by cytogenetic analysis, fluorescence in situ hybridization, molecular analysis of BCR/ABL-mRNA, and chimerism studies. These results show that in vitro cultured leukemia-reactive CTL lines selected on their ability to inhibit the proliferation of leukemic progenitor cells in vitro can be successfully applied to treat accelerated phase CML after allogeneic SCT.

Adult↗

Genomic organization, sequence and transcriptional regulation of the human CXCL 11(1) gene.

CXCL 11, encoded by the cDNA sequences designated beta-R1, H-174, or I-TAC, is a CXC chemokine ligand for CXCR3 and assumed to be involved in inflammatory diseases characterized by the presence of activated T-cells. We here describe the genomic organization (four exons interrupted by three introns of 585, 98 and 230 bp) and sequence including 960 bp from the immediate 5'-upstream region of the human CXCL 11 gene. Within the promoter region, consensus sequences for regulatory elements (ISRE, GAS, NF-kappaB) important for cytokine-induced gene transcription were identified. The effect of (pro)inflammatory cytokines on CXCL 11 mRNA expression in monocytic cell lines (THP-1, U937) and primary cultures of dermal fibroblasts and endothelial cells were examined using Northern blot analysis. For these cell types, IFN-gamma was a potent inducer of CXCL 11 transcription, which was synergistically enhanced by TNF-alpha.

Base Sequence↗

HLA-B8 and HLA-A3 coexpressed with HLA-B8 are associated with a reduced risk of the development of chronic myeloid leukemia. The Chronic Leukemia Working Party of the EBMT.

Chronic myeloid leukemia (CML) is characterized by the chromosomal translocation t(9;22) resulting in the chimeric bcr-abl oncogene that encodes the P210 fusion protein, which contains a unique amino acid sequence. If peptides derived from the leukemia-specific part of P210 are expressed in HLA molecules on the cell membrane of leukemic cells, an immunological response may occur. Recent studies using synthetic peptides identical to the bcr-abl fusion region showed that some peptides are capable of binding to HLA-A3, -A11, and -B8 molecules. Cytotoxic T-cell responses have been induced against bcr-abl-derived synthetic peptides bound to HLA-A3 and -B8. We hypothesized that if antigen processing of the P210 fusion protein leads to presentation of peptides from the fusion region by major histocompatibility complex (MHC) molecules in vivo, this may be reflected in a diminished incidence of CML in individuals expressing HLA-A3, -A11, or -B8. Consequently, lower frequencies of these antigens would be expected in patients with CML compared with unaffected individuals. A case-control study and a meta-analysis were performed to test this hypothesis. The multicenter case-control study compared patients with CML from the data base of the European Group for Blood and Marrow Transplantation (EBMT) with unaffected individuals from the registry of Bone Marrow Donors Worldwide. Patients and controls were matched per country. The meta-analysis consisted of five studies reported in the literature. The multicenter case-control study consisting of 1,899 patients and 512, 363 bone marrow donors as controls yielded odds ratios (ORs) of 0.90 (95% confidence interval [CI], 0.80 to 1.00) for HLA-A3, 1.16 (95% CI, 1.02 to 1.33) for HLA-A11, and an OR of 0.73 (95% CI, 0.65 to 0. 82) for HLA-B8. Coexpression of HLA-A3 and HLA-B8 gave an OR of 0.51 (95% CI, 0.40 to 0.67). This can be translated in a protective effect of 27% for HLA-B8, 10% for HLA-A3, and 49% protection for the combination of HLA-A3 and HLA-B8. The meta-analysis comprising 463 CML patients and 4,912 controls showed a 29% risk reduction for individuals expressing HLA-B8 (OR of 0.71; 95% CI, 0.52 to 0.97), but an OR of 1.19 (95% CI, 0.90 to 1.56) for HLA-A3 and an OR of 1. 09 (95% CI, 0.80 to 1.50) for HLA-A11. In conclusion, these results indicate that HLA-B8 expression, in particular when HLA-A3 is coexpressed, is associated with a diminished incidence of CML. A biological mechanism may be that presentation of bcr-abl breakpoint peptides in these HLA molecules can induce a protective immune response.

Case-Control Studies↗

Biology of IL-8-induced stem cell mobilization.

The CXC chemokine interleukin-8 (IL-8) has profound hematopoietic activities following systemic administration. It induces the rapid mobilization of cells with lymphomyeloid repopulating ability in mice and of hematopoietic progenitor cells in monkeys. In this paper, evidence is presented that stem cell mobilization in mice requires the functional expression on the beta 2-integrin leukocyte function-associated antigen-1 (LFA-1). In monkeys, systemic injection of IL-8 is followed by a significant increase in the circulating levels of the matrix metallo proteinase gelatinase-B (MMP-9). Based on these findings, the hypothesis is discussed that mature neutrophils serve as intermediate cells in IL-8-induced stem cell mobilization by the release of proteinases.

Animals↗

Murine hematopoietic progenitor cells with colony-forming or radioprotective capacity lack expression of the beta 2-integrin LFA-1.

Recently, we have demonstrated that antibodies that block the function of the beta2-integrin leukocyte function-associated antigen-1 (LFA-1) completely abrogate the rapid mobilization of hematopoietic progenitor cells (HPC) with colony-forming and radioprotective capacity induced by interleukin-8 (IL-8) in mice. These findings suggested a direct inhibitory effect of these antibodies on LFA-1-mediated transmigration of stem cells through the bone marrow endothelium. Therefore, we studied the expression and functional role of LFA-1 on murine HPC in vitro and in vivo. In steady state bone marrow +/- 50% of the mononuclear cells (MNC) were LFA-1(neg). Cultures of sorted cells, supplemented with granulocyte colony-stimulating factor (G-CSF)/granulocyte-macrophage colony-stimulating factor (GM-CSF)/IL-1/IL-3/IL-6/stem cell factor (SCF) and erythropoietin (EPO) indicated that the LFA-1(neg) fraction contained the majority of the colony-forming cells (CFCs) (LFA-1(neg) 183 +/- 62/7,500 cells v LFA-1(pos) 29 +/- 17/7,500 cells, P <.001). We found that the radioprotective capacity resided almost exclusively in the LFA-1(neg) cell fraction, the radioprotection rate after transplantation of 10(3), 3 x 10(3), 10(4), and 3 x 10(4) cells being 63%, 90%, 100%, and 100% respectively. Hardly any radioprotection was obtained from LFA-1(pos) cells. Similarly, in cytokine (IL-8 and G-CSF)-mobilized blood, the LFA-1(neg) fraction, which comprised 5% to 10% of the MNC, contained the majority of the colony-forming cells, as well as almost all cells with radioprotective capacity. Subsequently, primitive bone marrow-derived HPC, represented by Wheat-germ-agglutinin (WGA)+/Lineage (Lin)-/Rhodamine (Rho)- sorted cells, were examined. More than 95% of the Rho- cells were LFA-1(neg). Cultures of sorted cells showed that the LFA-1(neg) fraction contained all CFU. Transplantation of 150 Rho- LFA-1(neg) or up to 600 Rho-LFA-1(pos) cells protected 100% and 0% of lethally irradiated recipient mice, respectively. These results show that primitive murine HPC in steady-state bone marrow and of cytokine-mobilized blood do not express LFA-1.

Animals↗

Hairy cell leukemia-specific recognition by multiple autologous HLA-DQ or DP-restricted T-cell clones.

We studied in patients with hairy cell leukemia (HCL) whether autoreactive T cells could be isolated with specific reactivity to the HCL cells. HCL cells were activated via triggering of CD40 on the cell membrane and used as stimulator cells to generate autologous T-cell clones. Two types of CD4(+)BV2(+) T-cell clones with different CDR3 rearrangements and one type of CD4(+)BV8S3(+) T-cell clone were generated from the spleen or blood. These clones specifically recognized the autologous HCL cells, without reactivity to autologous peripheral blood mononuclear cells (PBMC), phytohemagglutinin blasts, or Epstein-Barr virus-transformed B cells in a primed lymphocyte test. Blocking and panel studies using HCL cells from 11 other patients showed that recognition of the HCL cells by the BV2(+) T cells was restricted by HLA-DQA1*03/DQB1*0301, and the BV8S3(+) T cells were restricted by DPB1*04. The T-cell clones did not recognize DPB1*04(+) or DQ3(+) PBMC from healthy donors or DP/DQ matched malignant cells from patients with other hematologic malignancies, except for one patient with acute lymphoblastic leukemia. These HCL-specific T-cell clones may be used for the detection of an HCL-specific tumor antigen.

Animals↗

Expression of Fas and Fas ligand in cutaneous B-cell lymphomas.

Primary cutaneous B-cell lymphomas (CBCLs) represent a rare, but distinct group of B-cell neoplasms with a different clinical behaviour to B-cell lymphomas secondarily involving the skin. Fas-Fas ligand (Fasl) expression was investigated in a group of primary and secondary CBCLs to gain an insight into the putative role of these apoptotic molecules in the clinical behaviour of these lymphomas. Frozen and paraffin sections from 32 patients with a CBCL were investigated for Fas and Fasl expression, using immunohistochemistry. This group included 24 primary CBCLs [14 primary cutaneous follicle centre cell lymphomas (PCFCCLs), six primary cutaneous large B-cell lymphomas (PCLBCLs) on the leg, and four primary cutaneous immunocytomas] and eight secondary CBCLs. The results were correlated with follow-up data, bcl-2, and ICAM-1 expression. High Fas expression and absent or low Fasl expression were detected in the vast majority of PCFCCLs and immunocytomas. The group of PCLBCLs on the leg, which have an intermediate prognosis, showed variable results with relatively higher Fasl expression. The highest Fasl expression was found in the more aggressive secondary CBCLs whereas in this group, Fas was undetectable in five of eight cases. Statistical analysis showed that Fas and ICAM-1 expression was strongly related to a favourable prognosis, whereas expression of Fasl and bcl-2 was related to a very poor prognosis. Although only type of CBCL and age, but not Fas, Fasl, bcl-2, and ICAM-1 expression, proved independent prognostic parameters using multivariate analysis, the results of this study suggest that differences in the expression of Fas and Fasl, as well as bcl-2 and ICAM-1, contribute to the differences in clinical behaviour between these different types of CBCL.

Adult↗

Impaired expression of CD28 on T cells in hairy cell leukemia.

T cells from patients with active hairy cell leukemia (HCL), a chronic B cell malignancy, show poor proliferation in response to allogeneic peripheral blood mononuclear cells (PBMC). In order to study the T cell dysfunction, the expression of several adhesion and costimulatory molecules was analyzed by flow cytometry. Circulating T cells from HCL patients showed increased percentages of CD28(-) in all T cell subsets. In some patients the percentage of CD28(-) T cells within the CD4(+) subset was increased up to 80%. These CD4(+)CD28(-) T cells did not proliferate in a mixed lymphocyte culture (MLC) against allogeneic PBMC. After enrichment for CD4(+)CD28(+) T cells, the proliferative response in the MLC was recovered, but this response was still lower than the proliferative response from control T cells. In conclusion, lack of CD28 on T cells and a restricted T cell repertoire may contribute to immune deficiency in patients with HCL.

Blood Donors↗

IP-10 mRNA expression in cultured keratinocytes is suppressed by inhibition of protein kinase-C and tyrosine kinase and elevation of cAMP.

IFN-gamma-inducible protein-10 (IP-10) is a chemokine, which plays an important role in mediating inflammation by attracting activated T cells, and it has been demonstrated in inflammatory skin diseases and cutaneous T cell lymphomas. Keratinocytes can abundantly produce IP-10 mRNA after IFN-gamma treatment. In this study we explored possibilities to downregulate IP-10 expression using human cultured keratinocytes as a model system. Decreased IP-10 mRNA levels were found using specific inhibitors of protein kinase (PK)-C (H-7 and Calphostin C). Moreover, depletion of PK-C by pretreatment of the cells with phorbol myristate (PMA) also down-regulated IP-10 mRNA expression. In addition, elevated cAMP levels were shown to inhibit IP-10 mRNA expression as could be concluded from experiments with forskolin and W-7, substances which, directly or indirectly, raise the intracellular cAMP level. With Genistein, an inhibitor of tyrosine kinase, the IFN-gamma-induced IP-10 mRNA expression was also found to be diminished. These data suggest that inhibitors of the IP-10 mRNA expression in cultured keratinocytes may be potentially of clinical relevance to suppress inflammatory processes in the skin.

Cells, Cultured↗

Primary cutaneous CD8-positive epidermotropic cytotoxic T cell lymphomas. A distinct clinicopathological entity with an aggressive clinical behavior.

Cutaneous T cell lymphomas (CTCL) generally have the phenotype of CD3+, CD4+, CD45RO+ memory T cells. CTCL expressing a CD8+ T cell phenotype are extremely rare and ill-defined. To elucidate whether these CD8+ CTCL represent a distinct disease entity, the clinical, histological, and immunophenotypical features of 17 CD8+ CTCL were reviewed. None of the 17 cases expressed markers characteristic of natural killer cells or gamma/delta T cells. Nine of 17 cases showed the characteristic clinical and histological features as well as clinical behavior of well defined types of CTCL, such as mycosis fungoides (2 cases), pagetoid reticulosis (2 cases), lymphomatoid papulosis (2 cases), and CD30+ large T cell lymphoma (2 cases), all of which usually express a CD4+ T cell phenotype, and 1 case of subcutaneous panniculitis-like T cell lymphoma. The other 8 cases formed a homogeneous group showing a distinctive set of clinicopathological and immunophenotypical features, not consistent with that of other well defined types of CTCL. Clinical characteristics included presentation with generalized patches, plaques, papulonodules, and tumors mimicking disseminated pagetoid reticulosis; metastatic spread to unusual sites, such as the lung, testis, central nervous system, and oral cavity, but not to the lymph nodes; and an aggressive course (median survival, 32 months). Histologically, these lymphomas were characterized by band-like infiltrates consisting of pleomorphic T cells or immunoblasts, showing a diffuse infiltration of an acanthotic epidermis with variable degrees of spongiosis, intraepidermal blistering, and necrosis. The neoplastic cells showed a high Ki-67 proliferation index and expression of CD3, CD8, CD7, CD45RA, betaF1, and TIA-1 markers, whereas CD2 and CD5 were frequently lost. Expression of TIA-1 pointed out that these lymphomas are derived from a cytotoxic T cell subset. The results of this and other studies reviewed herein suggest that these strongly epidermotropic primary cutaneous CD8+ cytotoxic T cell lymphomas represent a distinct type of CTCL with an aggressive clinical behavior.

Adult↗

Expression of cytotoxic proteins by neoplastic T cells in mycosis fungoides increases with progression from plaque stage to tumor stage disease.

Granzyme B (GrB) and T-cell-restricted intracellular antigen (TIA-1) are cytotoxic proteins that are specifically expressed by cytotoxic CD4 or CD8 positive T cells and natural killer cells. Recent studies demonstrated frequent expression of GrB and TIA-1 by neoplastic cells in primary cutaneous CD30(+) large T-cell lymphomas and lymphomatoid papulosis but not in CD30(-) large T-cell lymphomas. In the present study, 74 biopsies from 54 patients with mycosis fungoides (MF) were investigated for the expression of GrB and TIA-1 using immunohistochemistry on paraffin sections. Staining of more than 10% of the neoplastic T cells for GrB or TIA-1 was considered positive. All but two follow-up biopsies had been obtained from patients without extracutaneous disease at the time of biopsy. Expression of TIA-1 and GrB was found in 33 (45%) and 14 (19%) of 74 MF biopsies, respectively. Comparison of biopsies from T3NoMo-stage MF (n = 27) and T2NoMo-stage MF (n = 45) showed increased expression of TIA-1 (55 versus 37%) and GrB (33 versus 9%) in T3NoMo-stage MF. Evaluation of multiple sequential biopsies from successive stages of MF also revealed an increase in the GrB/TIA-1 expression with tumor progression in five of eight cases. A clearcut relation between the expression of TIA-1 and/or GrB and the type of skin lesion biopsied was found. Considering all 74 biopsies, expression of TIA-1 and GrB was found in 18 of 50 (35%) and 5 of 50 (10%) patches or plaques, 9 of 16 (55%) and 3 of 16 (20%) tumors without blastic transformation, and 6 of 8 (75%) and 6 of 8 (75%) tumors with blastic transformation (defined as >50% blast cells). Correlation between GrB/TIA-1 expression in first diagnostic biopsies from patches or plaques from 40 patients with T2NoMo-stage MF and clinical follow-up data did not reveal differences in clinical behavior and survival between patients with (n = 14) or without (n = 26) expression of cytotoxic proteins, indicating that MF expressing cytotoxic proteins should not be considered as a separate group.

Antigens, CD↗

Centre effect on treatment outcome for patients with untreated acute myelogenous leukaemia? An analysis of the AML 8A Study of the Leukemia Cooperative Group of the EORTC and GIMEMA. European Organization for Research and Treatment of Cancer (EORTC) Leukemia Cooperative Group and the Gruppo Italiano Malattie Ematologiche Maligne dell'Adulto (GIMEMA).

In the AML 8A study patients were treated with remission-induction therapy followed by one consolidation course. Patients in complete remission (CR) were randomised between autologous bone marrow transplantation (ABMT) and a second intensive consolidation course, except for those with a histocompatible sibling donor, who received allogeneic bone marrow transplantation (alloBMT). This analysis was performed to determine whether centres which only performed induction and consolidation therapy, achieved similar results as centres who also performed transplantation. 542/676 (80%) from transplantation centres and 150/194 (77%) from referring centres achieved CR, with an early death rate of 5% and 11%, respectively (P = 0.01). 66% of patients with a donor from transplantation centres received alloBMT in first CR compared with 57% from referring centres (P = 0.2). Transplantation centres randomised 64% of patients without a donor, referring centres 47% (P = 0.04). The full protocol treatment was completed by 275/542 (51%) and 61/150 (41%) patients, respectively (P = 0.04). The overall survival rate at 6 years from diagnosis was 34% and 36%, respectively (P = 0.9). In conclusion, the type of centre did not appear to have an influence on overall survival. The feasibility of the study was acceptable for both types of centres. The referring centres applied more selection for transplantation. Despite a more intensive second-line treatment at transplantation centres, the overall outcome remained similar to that of referring centres.

Acute Disease↗

Pentostatin in T-cell malignancies--a phase II trial of the EORTC. Leukemia Cooperative Group.

PURPOSE: Within this phase II EORTC trial, we have investigated the safety and efficacy of pentostatin in lymphoid malignancies. We have previously reported the results in T- and B-cell prolymphocytic leukemia, B-cell chronic lymphocytic leukemia (B-CLL) and hairy cell leukemia. This report focuses on the outcome in T-cell malignancies: T-CLL, Sézary syndrome (Sézary), mycosis fungoides (MF) and T-zone lymphoma (TZL). PATIENTS AND METHODS: Of the 92 patients with these diagnoses enrolled, 76 were evaluable for response and toxicity, i.e., 25 of 28 with T-CLL, 21 of 26 with Sézary, 22 of 26 with MF, and 8 of 12 with TZL. All patients had progressive and advanced disease. Pentostatin was administered at a dosage of 4 mg/m2 every week for the first 3 weeks, then 4 mg/m2 every 14 days for another 6 weeks, followed by maintenance therapy of 4 mg/m2 monthly for a maximum of 6 months. RESULTS: Response rates (complete and partial responses) in patients with Sézary (n = 22) or MF (n = 21) were 33% and 23%, respectively, and in patients with T-CLL (n = 21) or TZL (n = 8) 8% and 25%, respectively. Sixteen (21%) patients died during the first ten weeks of treatment: twelve of progressive disease, two of infectious complications with progressive disease, one of myocard infarction and one of renal failure related to administration of i.v. contrast. Major toxicity (grade 3-4) included infection in 11% of patients, nausea/vomiting in 4%, diarrhea in 3%. Hematologic toxicity was mild to non-existent. CONCLUSIONS: We conclude that pentostatin is active in Sézary and MF but showed marginal activity in T-CLL or TZL. Toxicities are mild to moderate at the dose schedule administered. Due to its relatively specific lympholytic effect and its favorable toxicity spectrum, pentostatin might be especially useful for the palliative treatment of T-cell malignancies.

Adult↗

The number of nucleated cells reflects the hematopoietic content of umbilical cord blood for transplantation.

A single umbilical cord blood (UCB) collection may contain sufficient hematopoietic stem cells to achieve engraftment and repopulation of the hematopoietic system of children and adults after myeloablative therapy. The hematopoietic potential of a UCB unit is often defined by the number of CD34+ cells or the number of colony-forming units as measured in semisolid hematopoietic progenitor cell (HPC) cultures. However, these assays are relatively difficult to standardize between UCB banks. The number of nucleated cells infused per kilogram body weight of the recipient is also reported to be a significant factor in the speed of recovery of neutrophils and platelets after transplantation. To analyze which parameters could be used to evaluate the hematopoietic potential of a UCB graft, we evaluated almost 300 UCB units that were collected for banking for unrelated transplantation. A strong correlation was found between the frequencies of CD34+ cells and the HPC as measured in semi-solid medium cultures. From the various leukocyte subpopulations, the concentration and total numbers of nucleated cells correlated best with both the HPC content and the number of CD34+ cells. Differentiation of these nucleated cells into subsets of leukocytes offered no advantage for better prediction of HPC or CD34+ cells. These results indicate that the nucleated cell count probably reflects the hematopoietic potential of a UCB graft, and may for that reason correlate with the speed of engraftment after transplantation.

Adult↗

Multicenter randomized phase II trial of idarubicin vs mitoxantrone, combined with VP-16 and cytarabine for induction/consolidation therapy, followed by a feasibility study of autologous peripheral blood stem cell transplantation in elderly patients with acute myeloid leukemia.

To compare the antileukemic efficacy of idarubicin and mitoxantrone in elderly patients with acute myeloid leukemia (AML) and to evaluate the feasibility of autologous transplantation using PBSC after consolidation in those with a good performance status, 160 patients (median age 69 years), with AML at diagnosis, 118 of them with de novo AML and 42 with AML secondary to myelodysplastic syndrome or toxic exposure (sAML), received induction treatment with idarubicin, 8 mg/m2/day or mitoxantrone, 7 mg/m2/day, on days 1, 3, and 5, both combined with VP-16, 100 mg/m2/day on days 1 to 3 and cytarabine (araC), 100 mg/m2/day, on days 1 to 7. G-CSF, 5 microg/kg/day, was administered after chemotherapy in patients aged more than 70 years. Patients in complete remission (CR) received one course of consolidation using the same schedule as for induction except the araC administration was shortened to 5 days. Some patients younger than 70 years were then scheduled for autologous stem cell harvest on days 5 to 7 of G-CSF, 5 microg/kg/day, initiated after hematopoietic recovery from consolidation. Autologous transplantation was performed following an additional chemotherapy conditioning. Ninety-five patients (59%) achieved CR, without significant difference between the idarubicin (56% CR) and mitoxantrone (63% CR) group. There was also no significant difference in CR rate between de novo AML (63%) and secondary AML (55%) (P = 0.12). Patients aged < 70 years had 67% CR, while patients aged > or = 70 years had 49% (P = 0.02). There was no significant difference in the duration of aplasia between the two arms. Median time to neutrophil recovery was 22 days in patients who received G-CSF following induction and 27 days in patients who did not (P = 0.006). Severe extrahematologic toxicities of induction did not differ between the two arms and included sepsis (39%), diarrhea (13%), hyperbilirubinemia (8%), hemorrhage (6%) and vomiting (6%). Overall, 14 patients (9%), died from toxicity of induction. First consolidation was administered in 74 patients of whom seven (9%) died from toxicity. Nineteen patients have received transplantation. Median time to recovery of neutrophils > 0.5 x 10(9)/l was 13 days and of platelets > 50 x 10(9)/l 43 days following consolidation. There were two toxic deaths. Median disease-free survival and survival from time of achieving CR of non transplanted patients are 6 and 7 months respectively without difference between the two arms. Fourteen transplanted patients relapsed at a median of 5 months post-transplant. We conclude that this regimen is well tolerated and has a good efficacy to induce CR, without a significant difference in efficacy and toxicity between idarubicin and mitoxantrone. Intensive postinduction, including transplantation, is feasible; however, this procedure did not seem to prevent early relapse in the majority of patients. Neither the high rate of CR nor consolidation nor transplant procedure in a selected group of patients did translate into improved DFS and/or survival.

Acute Disease↗