RESUMO
Chemotherapy plus G-CSF (C+G) and G-CSF alone are two of the most common methods used to mobilize CD34(+) cells for autologous hematopoietic SCT (AHSCT). In order to compare and determine the real-world outcomes and costs of these strategies, we performed a retrospective study of 226 consecutive patients at 11 medical centers (64 lymphoma, 162 multiple myeloma), of whom 55% of lymphoma patients and 66% of myeloma patients received C+G. Patients with C+G yielded more CD34(+) cells/day than those with G-CSF alone (lymphoma: average 5.51 × 10(6) cells/kg on day 1 vs 2.92 × 10(6) cells/kg, P=0.0231; myeloma: 4.16 × 10(6) vs 3.69 × 10(6) cells/kg, P<0.00001) and required fewer days of apheresis (lymphoma: average 2.11 vs 2.96 days, P=0.012; myeloma: 2.02 vs 2.83 days, P=0.0015), although nearly all patients ultimately reached the goal of 2 × 10(6) cells/kg. With the exception of higher rates of febrile neutropenia in myeloma patients with C+G (17% vs 2%, P<0.05), toxicities and other outcomes were similar. Mobilization with C+G cost significantly more (lymphoma: median $10,300 vs $7300, P<0.0001; myeloma: $8800 vs $5600, P<0.0001), although re-mobilization adds $6700 for drugs alone. Our results suggest that although both C+G and G-CSF alone are effective mobilization strategies, C+G may be more cost-effective for patients at high risk of insufficient mobilization.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/economia , Fator Estimulador de Colônias de Granulócitos/economia , Mobilização de Células-Tronco Hematopoéticas/economia , Transplante de Células-Tronco Hematopoéticas/economia , Adulto , Idoso , Anticorpos Monoclonais Murinos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ciclofosfamida/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Mobilização de Células-Tronco Hematopoéticas/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Rituximab , Transplante Autólogo/economia , Transplante Autólogo/métodos , Resultado do Tratamento , Adulto JovemRESUMO
Older patients with RAEB-T or AML are extremely difficult to treat. They are at high risk of infection and/or bleeding complications and have a low probability of cure and short overall survival with conventional treatments. We treated 12 patients with an outpatient low-dose chemotherapy regimen consisting of Ara-C 100 mg subcutaneously on day 1, and 6-thioguanine 80 mg orally on days 2-5, repeated every week. Nine patients had MDS, six RAEB-T, and three RAEB (median age 57 years) and three had de novo AML (median age 73 years). All patients were transfusion dependent. The mean peripheral blast count at the beginning of treatment was 29% (4-51%). The median follow-up is 13 months (2-34 months) for all the patients and 14 months (2-34 months) for those with RAEB-T. Nine of the 12 patients are alive, including seven RAEB-T patients with a median of 18 months (range 6-34+ months). During treatment, the peripheral blast count was markedly reduced to a mean of 5% (0-23%). The mean pre-therapy platelet count, with transfusion support, was 24.0 x 10(9)/l, while the mean post-therapy platelet count without transfusion support is 95.0 x 10(9)/l. All patients except two became transfusion independent at some time. Treatment for 6-10 weeks was required to show reduction of blast number and increase in hemoglobin, platelet, and WBC counts. Initial cytopenias were the only side effects of this regimen. One patient had granulocytopenic fever. In conclusion, this low-dose regimen is effective and well tolerated for outpatient palliation in high-risk or elderly patients with RAEB-T or AML.
Assuntos
Citarabina/administração & dosagem , Síndromes Mielodisplásicas/tratamento farmacológico , Tioguanina/administração & dosagem , Doença Aguda , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Esquema de Medicação , Feminino , Seguimentos , Humanos , Injeções Subcutâneas , Leucemia Mieloide/sangue , Leucemia Mieloide/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/sangue , Cuidados Paliativos , Transfusão de Plaquetas , Trombocitopenia/tratamento farmacológico , Trombocitopenia/terapiaRESUMO
Ten patients with Stage II (four) and Stage IV (six) breast cancer were enrolled in a trial of conventional-dose induction therapy followed by high-dose therapy with autologous bone marrow support. Cyclophosphamide, methotrexate, and 5-fluorouracil were given to best response or five courses (Stage II). Those patients without progression were eligible for the high-dose portion of the protocol, which consisted of carboplatin 1,500 mg/m2 and mitoxantrone at either 40 mg/m2 (first five patients) or 50 mg/m2. Two patients did not receive the high-dose portion of the treatment due to progression on induction therapy (one) and insurance refusal (one). Of the remaining eight patients who completed the high-dose portion of the protocol, three were Stage II, of whom one died of transplant-related complications, one progressed, and one is alive and free of disease 24 months after therapy. Of the five Stage IV patients, two achieved a partial remission, one of whom died of progressive disease 1 year after therapy and the other died of BMT-related complications; of the other three Stage IV patients, one had stable disease and died at +9 months, one with progression died at +3 months, and one died of BMT-related causes. Overall, three patients died of infectious complications, with two having alpha streptococcal septic shock syndrome.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante de Medula Óssea , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Adulto , Neoplasias da Mama/patologia , Carboplatina/administração & dosagem , Quimioterapia Adjuvante , Ciclofosfamida/administração & dosagem , Fluoruracila/administração & dosagem , Humanos , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Mitoxantrona/administração & dosagem , Estadiamento de Neoplasias , Análise de Sobrevida , Transplante AutólogoRESUMO
OBJECTIVE: To review the long-term outcome of patients with recurrent and refractory germ cell tumors treated with high-dose chemotherapy and autologous bone marrow rescue. DESIGN: Cohort study. SETTING: A university hospital. PATIENTS: Forty consecutive patients with recurrent or refractory germ cell tumors treated at Indiana University between September 1986 and June 1989. INTERVENTIONS: Patients were treated with high-dose carboplatin (900 to 2000 mg/m2 body surface area) and etoposide (1200 mg/m2). Three patients also received ifosfamide (10 g/m2). All patients had autologous bone marrow rescue. Of the 40 study patients, 26 received two full courses of therapy. MEASUREMENTS: Patient charts were reviewed to determine the rate and duration of complete and partial remission and the number of long-term, disease-free survivors. The influence of cisplatin-refractory disease and the site of the primary tumor on the incidence of remission and survival were also investigated. RESULTS: Of the 40 study patients, 26 (65%) responded to treatment; 12 (30%) achieved a complete response, and 14 (35%) achieved a partial response. Of the 12 complete responders, 5 relapsed, and 1 died of treatment-related acute leukemia 27.5 months after treatment without evidence of germ cell cancer. Six (15%) of the original 40 patients, of whom 3 were refractory to cisplatin, remained in complete remission after at least 24 months of follow-up. Eight of 40 patients had primary mediastinal germ cell tumors with no complete remissions and a median survival of 2 months (range, 0.5 to 9.0 months). CONCLUSIONS: Treatment with high-dose carboplatin and etoposide in conjunction with autologous bone marrow rescue in patients with relapsed or refractory germ cell tumors is a potentially curative therapeutic option, even for heavily pretreated or cisplatin-refractory patients. Some degree of disease resistance to cisplatin can be overcome with dose escalation of platinum compounds. Patients with multiple recurrences of relapsed or refractory primary mediastinal germ cell tumors were not helped by this approach.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Transplante de Medula Óssea , Neoplasias Embrionárias de Células Germinativas/terapia , Adulto , Cisplatino/uso terapêutico , Terapia Combinada , Resistência a Medicamentos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Indução de Remissão , Terapia de Salvação , Neoplasias Testiculares/terapia , Resultado do TratamentoRESUMO
The myelodysplastic syndromes are acquired clonal hematologic malignancies characterized by progressive cytopenia and an increased risk of evolution to acute myeloid leukemia. It mainly affects elderly people, but may also be found in younger patients and children. MDS represents a heterogeneous group of disorders. Some patients will experience prolonged survival, whereas a substantial number of patients will die within the first year after diagnosis. Treatment of patients should be based on life expectancy. Patients with pancytopenia, excess of bone marrow blasts, complex chromosome abnormalities, abnormal chromosome 7, older age and secondary MDS have a poor prognosis. Several simple scoring systems are available, based on peripheral counts, percent of bone marrow blasts and age, that provide significant prognostic information about life expectancy in patients with MDS. The most widely used is the Bournemouth scoring system. The prognostic factors and the scoring systems are reviewed.
Assuntos
Síndromes Mielodisplásicas/mortalidade , Crise Blástica , Exame de Medula Óssea , Humanos , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Oncogenes , Prognóstico , Análise de SobrevidaRESUMO
The major complications of the myelodysplastic syndromes (MDS) are related to cytopenia and evolution to acute myeloid leukemia (AML). Hematopoietic growth factors are only of limited benefit to alleviate the cytopenia. Therapy in MDS patients over the age of 50 should aim at prolonging survival while limiting the risk of toxicity. Those with stable disease should only receive supportive care; those with progressive cytopenia should have a trial with low-dose chemotherapy. Aggressive chemotherapy should only be reserved for those failing low-dose therapy. Therapy in MDS patients under the age of 50 should aim at cure of the disease. Although aggressive chemotherapy can induce complete remission in the majority of these patients, remission is usually short. Allogeneic bone marrow transplantation is probably the only curative option in these patients and should be the treatment of choice.
Assuntos
Síndromes Mielodisplásicas/complicações , Síndromes Mielodisplásicas/terapia , Antineoplásicos/uso terapêutico , Transplante de Medula Óssea , Doenças Hematológicas/etiologia , Humanos , Pré-LeucemiaRESUMO
The authors reported their experience with the use of high-dose chemotherapy and autologous bone marrow rescue (ABMR) as salvage therapy in the treatment of patients with recurrent and refractory primary nonseminomatous mediastinal germ cell tumors (PMGCT). Since 1987, the authors have treated 12 patients with PMGCT with high-dose carboplatin (1500 mg/m2 to 1800 mg/m2) and etoposide (1200 mg/m2 to 1350 mg/m2) (in two patients ifosfamide [10 g/m2] was added) with ABMR. Patients were either in second relapse or cisplatin refractory (progression within 4 weeks of last cisplatin dosing). They had received a median of two prior chemotherapy regimens (range, one to three), all had had prior cisplatin therapy, and most had failed ifosfamide-based therapy. Six patients were cisplatin refractory and of these only one achieved a partial response (PR) that was of short duration. It was planned that all patients would undergo two rounds of therapy; however, only 5 of 12 patients received two courses. The remainder had only one round of therapy either because of inadequate response (three patients) or excessive toxicity (four patients). There were four patients who died in the peritransplant period due to sepsis (two patients) or bleeding (two patients). The median survival of the group was 107 days (range, 14 days to 347 days). No patient achieved a complete remission, but there were six partial remissions, four with stable disease, and two with progressive disease. The use of high-dose carboplatin and etoposide with or without ifosfamide and ABMR was not effective in the treatment of this group of patients with PMGCT who were in second relapse or cisplatin refractory.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante de Medula Óssea , Neoplasias do Mediastino/terapia , Neoplasias Embrionárias de Células Germinativas/terapia , Adulto , Carboplatina/administração & dosagem , Cisplatino/administração & dosagem , Terapia Combinada , Etoposídeo/administração & dosagem , Humanos , Ifosfamida/administração & dosagem , Transplante AutólogoRESUMO
Leukemic cell growth in the marrow microenvironment may be modulated by stromal cell products, including stimulatory growth factors and the inhibitory regulator prostaglandin E. The production of both of these stromal cell products induced by cytokine mediators appears to be closely linked. Cyclic AMP (cAMP) is an intracellular second messenger that inhibits myeloid cell proliferation and is produced in myeloid leukemia cells on stimulation of adenylate cyclase enzyme by prostaglandin E1 (PGE1). Cells expressing the product of an RAS oncogene have been observed to display diminished hormone-stimulated adenylate cyclase of membranes. If this observation were applicable to myeloid cells, a potentially important mode for leukemia cells expressing p21 RAS to escape inhibitory regulation within the hematopoietic microenvironment would be identified. We studied an interleukin-3 (IL-3)-dependent myeloid cell line, NFS/N1.H7, and a derivative line transfected with H-RAS codon 12 (T24) oncogene, H7 Neo Ras.F3, for inhibition of proliferation by PGE1, 1 microM, alone or in combination with pertussis toxin, which inactivates Gi, an inhibitory regulatory guanosine triphosphate (GTP)-binding protein of adenylate cyclase. NFS/N1.H7 cells were inhibited in interleukin-3-dependent proliferation (dose range, IL-3 10 to 100 U/mL) by PGE1 79 +/- 11%, by pertussis toxin 51 +/- 9%, and by the combination 92 +/- 2%, whereas H7 Neo RAS.F3 was inhibited 51 +/- 7%, 6 +/- 2%, or 58 +/- 9% by PGE1, pertussis toxin, and the combination, respectively. These differences in capacity for inhibition by adenylate cyclase agonists between RAS-transfectant cells (lower inhibition) versus parent cells (greater inhibition) were all highly significant (P less than .0005). Intracellular cAMP formed on PGE1 stimulation of pertussis-intoxicated cells was 150% lower in RAS-transfectant cells than in parent cells. The adenylate cyclase activity of membranes from pertussis-intoxicated RAS-transfected cells was 1.5 to two times lower than that of pertussis-intoxicated parent-cell membranes on Mg2+-dependent activation by hormone and/or guanine nucleotide. However, very similar adenylate cyclase activity was observed in oncogenic p21 RAS-containing membranes compared with parental membranes under conditions of direct activation by 4 mM Mn2+ and forskolin, where inhibitory or stimulatory G-protein influences are minimal. These studies showed diminished adenylate cyclase activity in mutant RAS-bearing myeloid-cell membranes compared with parent-cell membranes independent of the pertussis toxin-sensitive G protein, Gi.(ABSTRACT TRUNCATED AT 400 WORDS)
Assuntos
Toxina Adenilato Ciclase , Adenilil Ciclases/fisiologia , Alprostadil/farmacologia , Células da Medula Óssea , Genes ras , Interleucina-3/farmacologia , Toxina Pertussis , Fatores de Virulência de Bordetella/farmacologia , Adenosina Difosfato Ribose/metabolismo , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Membrana Celular/enzimologia , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Inibidores do Crescimento , Técnicas In Vitro , Manganês/farmacologia , Camundongos , TransfecçãoRESUMO
Tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide, NSC 286193), a selective inhibitor of the activity of IMP dehydrogenase (EC 1.1.1.205), the rate-limiting enzyme of de novo GTP biosynthesis, provided in end stage leukemic patients a rapid decrease of IMP dehydrogenase activity and GTP concentration in the blast cells and a subsequent decline in blast cell count. Sixteen consecutive patients with end stage acute nonlymphocytic leukemia or myeloid blast crisis of chronic granulocytic leukemia were treated with tiazofurin. Allopurinol was also given to inhibit xanthine oxidase activity to decrease uric acid excretion and to elevate the serum concentration of hypoxanthine, which should competitively inhibit the activity of hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8), the salvage enzyme of guanylate synthesis. Assays of IMP dehydrogenase activity and GTP concentration in leukemic cells provided a method to monitor the impact of tiazofurin and allopurinol and to adjust the drug doses. In this group of patients with poor prognosis, five attained a complete hematological remission and one showed a hematological improvement. A marked antileukemic effect was seen in two other patients. All five evaluable patients with myeloid blast crisis of chronic granulocytic leukemia reentered the chronic phase of their disease. Five patients with acute nonlymphocytic leukemia were refractory to tiazofurin and three were unevaluable for hematological effect because of early severe complications. Responses with intermittent 5- to 15-day courses of tiazofurin lasted 3-10 months. Tiazofurin had a clear antiproliferative effect, but the pattern of hematological response indicated that it appeared to induce differentiation of leukemic cells. In spite of toxicity with severe or life-threatening complications in 11 of 16 patients, tiazofurin was better tolerated in most patients than other antileukemic treatment modalities and provided a rational, biochemically targeted, and biochemically monitored chemotherapy which should be of interest in the treatment of leukemias and as a paradigm in enzyme pattern-targeted chemotherapy.
Assuntos
IMP Desidrogenase/antagonistas & inibidores , Cetona Oxirredutases/antagonistas & inibidores , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide/tratamento farmacológico , Ribavirina/uso terapêutico , Ribonucleosídeos/uso terapêutico , Antimetabólitos Antineoplásicos , Crise Blástica , Contagem de Células Sanguíneas/efeitos dos fármacos , Medula Óssea/patologia , Inibidores Enzimáticos/uso terapêutico , Guanosina Trifosfato/metabolismo , Humanos , Leucemia Mieloide/enzimologia , Leucemia Mieloide/patologia , Leucemia Mieloide Aguda/enzimologia , Leucemia Mieloide Aguda/patologia , Ribavirina/análogos & derivadosRESUMO
The impact of tiazofurin on inhibition of IMP dehydrogenase was discussed at the clinical and molecular levels. 1. Evidence was provided for the role of IMP dehydrogenase and guanylates in the expression of the neoplastic program in cancer cells with particular relevance to human leukemic cells. 2. The argument for expecting an impact of tiazofurin in human myelocytic cells was provided. 3. Similarity of the kinetics of human leukemic cell IMP dehydrogenase to the rat hepatoma enzyme was documented. 4. New evidence was provided for the role of salvage in chemotherapy and the function of hypoxanthine in inhibiting guanine salvage. 5. The action of tiazofurin and retinoic acid was reported in HL-60 leukemic cells. 6. The effect of tiazofurin and retinoic acid on proliferation and cytotoxicity was outlined for hepatoma 3924A cells. 7. The effect of guanine on induced differentiation by tiazofurin and retinoic acid was examined. 8. Biochemical basis was provided for the lack of development of resistance in patients treated with tiazofurin. 9. Presumptive evidence was provided that tiazofurin treatment induced differentiation of leukemic cells in the patients. 10. The molecular biology of tiazofurin-induced differentiation in K-562 cells was reviewed with the possible relevance to clinical treatment that tiazofurin might also act through down-regulation of ras oncogene.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , IMP Desidrogenase/antagonistas & inibidores , Cetona Oxirredutases/antagonistas & inibidores , Ribavirina/farmacologia , Ribonucleosídeos/farmacologia , Células Tumorais Cultivadas/citologia , Animais , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Guanosina/farmacologia , Humanos , Leucemia Promielocítica Aguda , Neoplasias Hepáticas Experimentais/enzimologia , Neoplasias Hepáticas Experimentais/patologia , Ratos , Ribavirina/análogos & derivados , Tretinoína/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/enzimologiaRESUMO
Four methods, latex agglutination, indirect fluorescent antibody, enzyme immunoassay, and complement fixation, were compared for cytomegalovirus antibody screening and for pre- and posttransplant determinations on bone marrow transplant recipients. Latex agglutination was most sensitive (98%) and specific (97%) for screening and pretransplant determinations and was quickest and easiest to perform. In posttransplant sera from allogeneic bone marrow transplant recipients, all methods except complement fixation detected cytomegalovirus antibody from therapeutically administered globulin preparations; this made it difficult to determine the significance of changes in cytomegalovirus antibody titer.
Assuntos
Anticorpos Antivirais/análise , Transplante de Medula Óssea , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Testes de Fixação de Complemento , Imunofluorescência , Humanos , Técnicas Imunoenzimáticas , Testes de Fixação do Látex , Valor Preditivo dos TestesRESUMO
Tiazofurin through its active metabolite thiazole-4-carboxamide adenine dinucleotide (TAD) inhibits IMP dehydrogenase, the rate-limiting enzyme of GTP biosynthesis. IMP dehydrogenase activity in human leukemic cell extracts (33.4 +/- 0.1 nmol/h/mg protein) was increased 11-fold compared to normal leukocytes (3.1 +/- 0.5). Km values for IMP and NAD+ of leukemic IMP dehydrogenase were 22.7 and 44.0 microM, respectively. XMP inhibited competitively with IMP and noncompetitively with NAD+. NADH exerted mixed type inhibition with respect to both IMP and NAD+. The inhibitory pattern of TAD was quite similar to that of NADH; however, the affinity of TAD to leukemic IMP dehydrogenase (Ki = 0.1 microM) was three orders of magnitude higher than the natural product NADH (Ki = 150 microM). These results contribute to an understanding of the mechanism of action of tiazofurin in the treatment of leukemia.
Assuntos
Antineoplásicos/farmacologia , Crise Blástica/enzimologia , IMP Desidrogenase/antagonistas & inibidores , Cetona Oxirredutases/antagonistas & inibidores , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Ribavirina/farmacologia , Ribonucleosídeos/farmacologia , Nucleotídeos de Adenina/farmacologia , Crise Blástica/sangue , Crise Blástica/tratamento farmacológico , Feminino , Humanos , IMP Desidrogenase/sangue , Cinética , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Pessoa de Meia-Idade , NADP/metabolismo , Ribavirina/análogos & derivadosRESUMO
The factors that initiate and maintain the abnormal hematopoietic clone in the myelo-dysplastic syndromes (MDS) remain largely unknown. We describe a patient with MDS associated with an abnormal karyotype, 46,XY,t(5;12)(q31;p12). According to the FAB cooperative group classification, the patient was classified as chronic myelomonocytic leukemia. Because of the particular chromosomal translocation, the structure-function relationship of three genes relevant to the translocation breakpoints, CSF2, FMS, and KRAS2, was studied in bone marrow and peripheral blood lymphocytes in this patient. No major structural alterations were observed at these three genetic loci. Although the levels of expression of the CSF2 and FMS genes remained unaltered, the KRAS2 oncogene was overexpressed approximately six-fold in bone marrow cells from the MDS patient compared with normal donors. We postulate that the RAS oncogene activation may be instrumental in the genesis of MDS.
Assuntos
Cromossomos Humanos Par 12 , Cromossomos Humanos Par 5 , Síndromes Mielodisplásicas/genética , Oncogenes , Translocação Genética , Adulto , Southern Blotting , Ciclo Celular , Bandeamento Cromossômico , DNA/genética , Marcadores Genéticos , Humanos , Cariotipagem , Masculino , Síndromes Mielodisplásicas/patologiaRESUMO
The hypothesis was tested that the increased IMP dehydrogenase activity in human myelocytic leukemic cells, and along with it guanylate biosynthesis, might be a sensitive target to chemotherapy by tiazofurin. 1. IMP dehydrogenase activity in normal leukocytes was 3.1 +/- 0.5 (means +/- S.E.) nmol/hr/mg protein and in leukemic cells it was elevated 15- to 41-fold. The activity of guanine phosphoribosyltransferase in normal leukocytes was 389 +/- 27 nmol/hr/mg protein and in the leukemic cells it increased 2.8- to 6.8-fold. 2. IMP dehydrogenase was purified 4,900-fold to homogeneity from rat hepatoma 3924A with a yield of 30%. The kinetic properties of the hepatoma enzyme were similar to those of the enzyme in human myelocytic leukemic blast cells because of the similarity of the Km's for IMP (23 microM), NAD (44 and 65 microM); the Ki for TAD was 0.1 microM in both enzymes. 3. There was a selectivity of the in vitro response to tiazofurin in human normal and leukemic leukocytes. When labeled tiazofurin was incubated with leukocytes from normal, healthy volunteers and from leukemic patients, the leukemic leukocytes made 20- to 30-fold more TAD and the GTP content decreased as compared to normal leukocytes. This procedure proved to be a suitable predictive test in a clinical setting because patients with positive tests responded to tiazofurin whereas those with negative ones did not. 4. The National Cancer Institute approved a chemotherapeutic phase I/II trial which concentrates on treatment of refractory acute myelocytic leukemia. Tiazofurin is infused in a 60-minute period with a pump to insure uniform delivery. A novel aspect of the trial was that it was directed primarily by the biochemical impact of tiazofurin on IMP dehydrogenase activity and GTP concentration and the tiazofurin doses were to be adjusted accordingly. Patients received allopurinol as a routine precaution against possible accumulation of uric acid in the kidney. 5. In the first eight patients, there was one complete remission, two entered the chronic phase, two entered into partial remission, one did not respond, and two were not evaluable. In the five patients who responded, there was a rapid, profound decrease in IMP dehydrogenase activity of the blast cells and a gradual decline in GTP concentrations. The blast cell count followed the decrease in the GTP concentration. The white blood cell count was largely preserved. 6. Bone marrow aspirates and peripheral blood samples showed that with tiazofurin treatment there was an induced differentiation of the myelocytes.(ABSTRACT TRUNCATED AT 400 WORDS)
Assuntos
Alopurinol/uso terapêutico , IMP Desidrogenase/metabolismo , Cetona Oxirredutases/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Ribavirina/uso terapêutico , Ribonucleosídeos/uso terapêutico , Adenina/biossíntese , Idoso , Animais , Avaliação de Medicamentos , Feminino , Guanina/biossíntese , Guanosina Trifosfato/fisiologia , Humanos , Leucemia/enzimologia , Neoplasias Hepáticas Experimentais/metabolismo , Masculino , Pessoa de Meia-Idade , Ratos , Ribavirina/análogos & derivados , Células Tumorais Cultivadas/metabolismoRESUMO
It is important to make the correct diagnosis of MDS and to exclude very carefully all other disorders that may induce dysplastic features in the bone marrow. In patients without excess of bone marrow blasts, cytogenetics and in vitro bone marrow cultures may aid in making the correct diagnosis. MDS patients without excess of bone marrow blasts or symptomatic cytopenia or cytogenetic abnormalities associated with poor prognosis should be followed on a regular basis with sequential examinations of blood counts and bone marrow specimens. In the absence of obvious disease progression, ie, increasing cytopenia or increasing percentage of marrow blasts, patients should only receive supportive care. An increase in RBC requirements alone is insufficient reason to start cytotoxic therapy. Once progression of the disease has been well documented, cytotoxic treatment is indicated. There is no reason to delay treatment until these patients have progressed to overt AML. In patients over the age of 50, the best available therapy is low-dose cytarabine with a 30% probability of a good response; this therapy requires careful supervision and the availability of intensive supportive care. In patients under 50 years with progressive disease, or with clear evidence of a poor prognosis, allogeneic BMT is the therapy of choice if a HLA-identical sibling can be identified. In those patients who lack a HLA-identical sibling, intensive combination therapy is the treatment of choice and should preferably include high-dose cytarabine. Intensive consolidation therapy will be necessary for a durable remission. Trials with inducers of differentiation remain experimental. Results to date have been disappointing.
Assuntos
Síndromes Mielodisplásicas/tratamento farmacológico , Transplante de Medula Óssea , Colecalciferol/uso terapêutico , Terapia Combinada , Citarabina/administração & dosagem , Hormônios/uso terapêutico , Humanos , Tretinoína/uso terapêuticoRESUMO
A patient with refractory acute myeloid leukemia was treated with tiazofurin, an agent that causes inhibition of tumor cell proliferation by depressing GTP concentrations in the malignant cells. The initial dose of 1100 mg/m2 was ineffective clinically and biochemically. Dose escalations to 1650, 2200, and finally 3300 mg/m2 resulted in a marked decrease in the absolute number of blasts without causing bone marrow hypoplasia or marked neutropenia. The decrease in the peripheral blast cell count was observed subsequent to a decline in GTP concentrations in the leukemic cells to less than 30% of the pretreatment value. Consecutive bone marrow examinations showed a remarkable shift from myeloblasts to more mature myeloid elements, suggesting an in vivo differentiative action of tiazofurin. Although a total dose of 23,650 mg/m2 was administered over a 13-day period, only very mild side effects were noted. The absence of complications reported by others in Phase I trials with tiazofurin may be related to our slow administration of the drug by pump over a 1-h period in this trial. Tiazofurin appears to be a promising agent in the treatment of leukemia because of its selective action on leukemic cells and the availability of a rapid in vitro method capable of predicting sensitivity of leukemic cells to the agent and monitoring its activity during treatment by measuring thiazole-4-carboxamide adenine dinucleotide and GTP concentrations. These observations are being tested in a larger group of leukemic patients.
Assuntos
Antineoplásicos/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Ribavirina/uso terapêutico , Ribonucleosídeos/uso terapêutico , Medula Óssea/efeitos dos fármacos , Guanosina Trifosfato/análise , Humanos , Leucemia Mieloide Aguda/sangue , Leucemia Mieloide Aguda/metabolismo , Masculino , Pessoa de Meia-Idade , Ribavirina/efeitos adversos , Ribavirina/análogos & derivados , Ribavirina/metabolismoAssuntos
Leucemia de Células Pilosas/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Clorambucila/uso terapêutico , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Seguimentos , Humanos , Leucemia de Células Pilosas/diagnóstico , Leucemia de Células Pilosas/tratamento farmacológico , Leucemia de Células Pilosas/fisiopatologia , Contagem de Leucócitos , Estadiamento de Neoplasias , Contagem de Plaquetas , Prednisona/administração & dosagem , Prognóstico , Esplenectomia , Vincristina/administração & dosagemRESUMO
Two white European males are reported with adult T-cell leukemia (ATL), a disease first described in Japan, but recently also in the U.K. and U.S.A. Both patients presented with lymphadenopathy, but without a mediastinal mass. In addition, one patient had skin infiltrates and the other had hepatosplenomegaly. Morphologic and ultrastructural examination of the blasts in bone marrow and lymph node biopsy revealed a predominance of polymorphic lymphoid cells with pronounced nuclear irregularities and a semi-mature chromatine pattern. Histopathology of the lymph nodes showed a diffuse infiltration with medium-sized lymphoblasts with irregular nuclei. The blasts in the bone marrow formed E rosettes with sheep erythrocytes, lacked terminal deoxynucleotidyl transferase (Tdt) activity but expressed the Ia-like antigen; although the majority of the cells reacted with a polyclonal anti-T-cell serum, they were negative for OKT3. In one patient a helper/inducer phenotype (OKT4+) was found in the lymphoblasts of bone marrow and lymph node, while in the other only in the lymph node. The difference between bone marrow and lymph node phenotype is discussed. To our knowledge, these are the first two European patients reported with ATL, a disease clearly different from convoluted T-cell acute lymphocytic leukemia.