RESUMO
BACKGROUND: Administration of granulocyte-macrophage colony stimulating factor (GM-CSF) is followed by a rapid increase in the proliferative activity of the hematopoietic precursors. Within 72 hours after its suspension, however, establishment of a negative feedback results in a reduction of the proliferative activity of the hyperplastic marrow to values below the baseline, suggesting refractoriness of hematopoietic progenitors to the action of cell-cycle-specific cytostatic agents. METHODS: The hypothesis that short treatment with GM-CSF before chemotherapy could reduce the hematopoietic toxicity of cytostatics was investigated by administering GM-CSF glycosylate (Sandoz, Basel, Switzerland/Schering-Plough, Kenilworth, NJ) subcutaneously with a 5.5 micrograms/kg protein dosage per day from day-6-day-4 before each course of adjuvant chemotherapy (cyclophosphamide, epirubicin, 5-fluorouracil/cyclophosphamide, methotrexate, 5-fluorouracil alternate) in patients with node-positive breast cancer. Twelve patients were randomized to receive GM-CSF before chemotherapy or only at chemotherapy. The hematologic picture and dose intensity of chemotherapy were compared in the two groups of patients. RESULTS: In the group of patients receiving chemotherapy only, 22% of the cycles had to be postponed because of leukopenia, with a consequent reduction of the dose intensity, whereas in the GM-CSF group, the neutrophil counts remained at significantly (P < 0.001) higher levels, and there were no delays in chemotherapy administration. No substantial systemic toxicity was associated with this brief GM-CSF schedule. Moreover, GM-CSF treatment did not result in delayed depletion of the hematopoietic pool. CONCLUSIONS: Short treatment with GM-CSF can enable the dose intensity of conventional protocols of proven efficacy to be increased.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Hematopoese/efeitos dos fármacos , Neutropenia/prevenção & controle , Trombocitopenia/prevenção & controle , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/terapia , Ciclofosfamida/administração & dosagem , Ciclofosfamida/efeitos adversos , Esquema de Medicação , Epirubicina/administração & dosagem , Epirubicina/efeitos adversos , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Humanos , Metotrexato/administração & dosagem , Metotrexato/efeitos adversos , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Trombocitopenia/induzido quimicamenteRESUMO
Based on pre-clinical findings and on more recent preliminary in vivo data it has been suggested that immunotherapy with Interleukin 2 (IL2) may be employed in the treatment of acute leukemia patients. Here we shall discuss the biological and clinical observations which indicate that this innovative therapeutic approach may play a role in the management of minimal residual disease.
Assuntos
Interleucina-2/uso terapêutico , Leucemia/terapia , Doença Aguda , Humanos , Interleucina-2/genética , TransfecçãoRESUMO
In an attempt to prolong disease-free survival in children with acute leukemia, we tested the feasibility of interleukin-2 (IL-2) administration after an autologous bone marrow transplantation (ABMT). We report the clinical and biological data obtained in three children with acute myelocytic leukemia (AML) in second complete remission (CR) and in seven children with acute lymphocytic leukemia (ALL) in second or subsequent CR, who received IL-2 at a median interval of 78 days (range 38-125) from ABMT. Patients were treated with 1-2 cycles of IL-2 given by continuous infusion over a 5-day period using a daily escalating protocol, from 100 micrograms/m2 per day to the maximum tolerated dose, followed after 3 weeks by low-dose IL-2 for 5 days monthly over a 6-h infusion on an out-patient basis. Side effects greater than grade 2 (WHO system), consisting of thrombocytopenia, fever, cutaneous rash, nausea and vomiting, diarrhoea were common during the high-dose IL-2 cycles, but resolved 24-48 h after stopping IL-2. Only one patient developed liver toxicity (grade 3, WHO) on day +3 of the first cycle which prompted us to stop the administration of IL-2. An increase in lymphocytes and eosinophils was also observed. IL-2 treatment was followed by a normalization of NK function and by the generation of a high proportion of endogenous LAK cells. All seven ALL patients relapsed at a median of 5 months (range 1-23). Two AML patients relapsed at 1 and 11 months, while the other is still in continuous CR at 23 months after IL-2 treatment. Our IL-2 schedule for treatment of leukemia in children after ABMT is thus feasible but its efficacy requires further investigation.
Assuntos
Transplante de Medula Óssea , Interleucina-2/uso terapêutico , Leucemia Mieloide Aguda/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Criança , Pré-Escolar , Terapia Combinada , Feminino , Humanos , Células Matadoras Ativadas por Linfocina/efeitos dos fármacos , Células Matadoras Naturais/efeitos dos fármacos , Leucemia Mieloide Aguda/imunologia , Masculino , Projetos Piloto , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Proteínas Recombinantes/uso terapêutico , Transplante AutólogoAssuntos
Interleucina-2/uso terapêutico , Leucemia Mieloide Aguda/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Crise Blástica/terapia , Transplante de Medula Óssea , Humanos , Leucemia Mieloide Aguda/patologia , Proteínas Recombinantes/uso terapêutico , Indução de RemissãoRESUMO
In this paper we review some of the preclinical findings which have led us to believe that immunotherapy with interleukin 2 (IL2)/lymphokine activated killer (LAK) cells may be a feasible approach in the management of acute myeloid leukemia. The main clinical and biological results so far obtained with IL2 treatment, and the currently ongoing protocols and strategies are discussed.
Assuntos
Interleucina-2/uso terapêutico , Leucemia Mieloide/terapia , Doença Aguda , Adulto , Criança , Esquema de Medicação , Estudos de Viabilidade , Humanos , Infusões Intravenosas , Itália , Indução de RemissãoRESUMO
Thanks to the impressive development and application of new sophisticated technologies, the last decade has offered remarkable advances in our understanding of the molecular and biological features of human neoplastic cells. DNA analysis in particular has contributed to the unravelling of some of the possible events which give rise to a transformed cell and which enable it to proliferate indiscriminately and to infiltrate. Cloning techniques which have allowed researchers to obtain and utilize purified molecules represent another milestone. This has opened the era of cytokines and growth factors, both in terms of their possible role in the establishment and/or progression of neoplastic conditions (autocrine/paracrine models) and of their use in clinical practice. Thus, growth factors such as granulocyte-macrophage colony stimulating factors (GM-CSF) and interleukin 3 (IL-3) are currently being employed in the management of cancer patients, mainly to support normal hemopoiesis. Conversely, recombinant interleukin 2 (IL-2) through its unique capacity to generate previously unrecognized cytotoxic activity, lymphokine active killer (LAK), has brought about new and more specific immunotherapeutic strategy. Further therapeutic possibilities will arise from the clinical use of monoclonal antibodies. Finally, the development of genetic engineering has opened the way to the early and revolutionary clinical exploitation of gene therapy; the possibility of utilizing in vivo anti-sense oligonucleotides in an attempt to block the action of specific genes is also being contemplated.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Oncologia/tendências , Oncogenes , Transformação Celular Neoplásica/genética , Humanos , Metástase Neoplásica , Neoplasias/genética , Neoplasias/terapia , Células Neoplásicas CirculantesRESUMO
In 26 myeloid and lymphoid acute leukemia patients at presentation the capacity to generate interleukin-2 (IL-2)-induced lymphokine-activated killer (LAK) cells effective against the natural killer (NK)-resistant Raji cell line, as well as the susceptibility of the blasts to normal peripheral blood (PB) LAK cells and to autologous LAK effectors was analyzed. The overall PB LAK activity against Raji cells was significantly lower in acute leukemia patients compared with normal controls (mean, 1,473 +/- 971 SD LU/10(8) LAK effectors v 3,340 +/- 1,862; P less than .001). The sensitivity of the blasts to autologous LAK cells was also significantly lower than to normal LAK effectors (517 +/- 593 LU/10(8) LAK effectors v 1,304 +/- 1,066; P less than .01). When the data were analyzed independently, four patterns of behavior could be recognized. The relatively largest group (9 of 26) included patients in whom effective LAK cells could be generated against the Raji line, but in whom the blasts were resistant to autologous PB-LAK effectors while being susceptible to normal LAK cells (defective specific LAK activity). In 5 of 26 cases, an incapacity to generate LAK activity against both allogeneic and autologous target cells was observed (defective LAK generation). In six further cases, the blasts were resistant to both allogeneic and autologous LAK populations, though the latter were effective against the Raji line (resistant blasts). The same defects could also be shown with bone marrow-derived LAK cells. Only in six cases did the leukemic blasts appear susceptible to autologous and allogeneic LAK cells. In four patients the analysis could be repeated at remission, and in three a restoration of the LAK function against the primary blasts was recorded. In the 10 cases studied at relapse, the blasts were resistant to autologous LAK effectors in nine and to normal LAK in seven. These data demonstrate that in most acute leukemia patients with active disease, a defect of the LAK machinery, either a deficient generation of LAK cells or the resistance of the blasts to LAK effectors, may be documented, pointing therefore to a possible contributory role of the LAK system in the control of leukemic cell growth. In view of the frequent normalization of the autologous LAK activity at the time of remission, immunotherapy with IL-2/LAK cells should be primarily aimed to patients with minimal residual disease.
Assuntos
Células Matadoras Ativadas por Linfocina/imunologia , Leucemia Mieloide Aguda/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Linhagem Celular , Citotoxicidade Imunológica , Humanos , Linfócitos/imunologiaRESUMO
Twelve patients with acute myeloid leukaemia (AML) with evidence of resistant disease were treated with recombinant interleukin 2 (rIL2) given intravenously by continuous infusion. No objective response to rIL2 alone was documented in the seven patients with advanced disease (20-90% resistant blasts in the marrow), except for a partial response to rIL2 plus chemotherapy in one. Of the five patients with limited disease (8-15% marrow blasts), three obtained a complete disappearance of the blasts following two to four 5d courses of rIL2 alone. One patient persists in fourth complete remission (CR) 30 months later, another obtained a third CR for 4 months, and the last remained in third CR for 9 months before relapsing. This latter patient achieved a fourth CR with low-dose cytarabine. The remissions have been maintained with low-dose monthly courses of rIL2 given on an out-patient basis. Two AML did not respond to rIL2 alone; one, however, obtained a fourth CR with chemotherapy and rIL2. Administration of rIL2 was accompanied by organomegaly and leucocytosis, with a frequent lymphocytosis and increase in eosinophils and large granular lymphocytes, both in the blood and in the marrow. Side effects, though often severe, were controllable using a daily dose escalating protocol and never required intensive care treatment. The results of this pilot study indicate that treatment of AML patients with rIL2 is feasible and may result in the disappearance of chemotherapy-resistant blasts in patients with limited but detectable disease. Further controlled trials in AML in CR appear warranted.
Assuntos
Interleucina-2/uso terapêutico , Leucemia Mieloide/terapia , Doença Aguda , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança , Terapia Combinada , Feminino , Humanos , Interleucina-2/efeitos adversos , Leucemia Mieloide/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico , Indução de RemissãoRESUMO
Sixty-three cases of Hodgkin's disease in intravenous drug users (IVDUs) have been collected by the Italian Cooperative Group on AIDS-Related Tumors (GICAT). In most patients (74%) the histological pattern was that of mixed cellularity and lymphocyte depletion. In 39% of patients the initial symptom was a persistent lymph node enlargement due to persistent generalized lymphadenopathy (PGL). Unusual presentations included Waldeyer's ring, skin, meninges, colon, and pleura. After MOPP alternated or followed by ABVD, MOPP alone, or ABVD alone, 15 of 32 patients (47%) had a complete remission (CR) and 15 of 32 (47%) had a partial remission (PR). The median duration of CR was 14 months, while the median survival of patients with CR has not been reached; the median survival of patients treated with chemotherapy who had CD4 levels at presentation greater than or equal to 400/mm3 was significantly superior to that of those who had CD4 less than 400/mm3. The overall median survival was only 14 months. Forty-four percent of patients receiving chemotherapy, with or without radiotherapy, developed opportunistic as well as nonopportunistic infections. Lethal hepatic toxicity was observed in one patient. Among IVDUs, unusual presentations of Hodgkin's disease occurred at a lower rate than was previously reported for homosexuals. Complete remissions could be achieved in almost half the patients, but non opportunistic infections, in addition to parenchymal function impairment due to drug abuse, may limit treatment administration in IVDUs.
Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Doença de Hodgkin/etiologia , Abuso de Substâncias por Via Intravenosa/complicações , Síndrome da Imunodeficiência Adquirida/mortalidade , Síndrome da Imunodeficiência Adquirida/terapia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bleomicina/administração & dosagem , Terapia Combinada , Dacarbazina/administração & dosagem , Doxorrubicina/administração & dosagem , Epirubicina/administração & dosagem , Feminino , Seguimentos , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/mortalidade , Humanos , Masculino , Mecloretamina/administração & dosagem , Infecções Oportunistas/complicações , Prednisona/administração & dosagem , Procarbazina/administração & dosagem , Indução de Remissão , Taxa de Sobrevida , Vimblastina/administração & dosagem , Vincristina/administração & dosagemRESUMO
The effect of treatment with interleukin 2 (IL2) on the phenotypic and functional immune system of acute leukemia patients was investigated. Fifteen acute myeloid leukemia and acute lymphoid leukemia patients with evidence of persistent disease were further subdivided into two groups according to the percentage of bone marrow (BM) blasts: group a had 6-15% blasts and group b had 30-65%. Following two cycles of IL2 (Glaxo Imb, Geneva, Switzerland) given i.v. by continuous infusion at escalating doses, no major changes in the proportion of CD3-, CD4-, and CD8-positive cells were encountered in the blood or in the marrow of either group of patients. When these could be retested after four cycles of IL2, a significant increase of CD3+ and CD4+ cells was documented in the peripheral blood (PB), as well as a significant increase of CD3+ cells in the BM. Irrespective of the number of cycles administered, the proportion of CD16+ cells increased significantly in the blood in both groups of patients and in the marrow of group a patients only. The expression of CD25 was significantly enhanced in all samples tested. Following IL2 administration, an enhancement of the natural killer compartment was documented. This was consistently more evident in patients with more limited disease. A significant amplification of the in vitro-induced lymphokine-activated killer function was noted in the BM of the treated patients. Furthermore, we documented the presence both in the PB and in the BM of "spontaneous" lymphokine-activated killer cells generated in vivo following IL2 administration. These results demonstrate that in acute leukemia of both myeloid and lymphoid origin, treatment with IL2 is capable of inducing profound immunophenotypic and functional modifications in PB and in BM lymphocytes, particularly in patients with more limited disease. The evidence of the in vivo activation of cytotoxic cells, particularly in the BM, may help to explain the clinical responses preliminarily observed in individual acute leukemia patients.
Assuntos
Imunofenotipagem , Interleucina-2/uso terapêutico , Células Matadoras Ativadas por Linfocina , Células Matadoras Naturais , Leucemia Mieloide/imunologia , Leucemia Mieloide/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Doença Aguda , Adolescente , Adulto , Criança , Feminino , Humanos , Células Matadoras Ativadas por Linfocina/efeitos dos fármacos , Células Matadoras Naturais/efeitos dos fármacos , Leucemia Mieloide/sangue , Masculino , Pessoa de Meia-Idade , Fenótipo , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangueRESUMO
Fifty cases of Hodgkin's disease in intravenous drug users (IVDU) have been collected by the Italian Cooperative Group on AIDS-Related Tumors (G.I.C.A.T.). Ninety-two per cent of the patients were males; the median age was 26 years. Persistent generalized lymphadenopathy (PGL) at onset was present in 54% of patients, AIDS in 9%, ARC in 9% while 28% were simply HIV-positive. The initial median absolute number of CD4 lymphocytes was 264/mmc. Opportunistic infections were diagnosed in 20% of patients. In most patients the histological pattern was that of mixed cellularity and lymphocytic depletion (76%). In almost half the initial symptom was a persistent lymph node enlargement due to PGL. In the majority of patients (58%) only a clinical staging and bone marrow biopsy could be performed due to the presence of opportunistic infections, rapid disease progression or refusal of pathologic staging procedures. One patient presented with a Waldeyer's ring involvement, but no other unusual presentations were observed. After MOPP alternated or followed by ABVD or MOPP alone, 15/29 CR (52%) and 14/29 PR (48%) were observed. The median duration of CR was 14 months, while the median survival of CR has not been reached; the median survival of patients treated with chemotherapy with CD4 values at presentation {geq}400/mmc was significantly superior to that in those with CD4 < 400/mmc. The overall median survival was 16 months. Twenty-eight per cent of patients receiving chemotherapy + radiotherapy developed opportunistic as well as non-opportunistic infections (21%). Lethal hepatic toxicity was observed in 2 patients. In conclusion, Hodgkin's disease in IVDU was not found to be associated with unusual presentations, as previously reported for homosexuals. Complete remissions could be achieved in over 50% of patients, but in IVDU non-opportunistic infections in addition to opportunistic infections may also limit treatment administration. The presence of parenchymal functional impairment due to drug abuse, or drug abuse-related infections, such as pneumonia, endocarditis and hepatitis, should lead to the choice of antitumour agents with no or only minor potential liver, lung and cardiac toxicity.
RESUMO
A new and rare type of Bcr/Abl junction between exon C3 of the 3' portion of the Bcr gene and Abl exon 2 has been identified in the leukemic cells of two Ph1-positive chronic myelogenous leukemia patients in chronic phase. This is the fourth type of Bcr/Abl junction so far identified in Ph1-positive hematologic malignancies and is a consequence of an unusual breakpoint position on chromosome 22 that falls approximately 20 kb downstream of the major breakpoint cluster region (bcr) of the Bcr gene. The new hybrid mRNA is 540 base pairs (bp) longer than that expressed by the K562 cell line and could codify for a Bcr/Abl protein carrying 180 additional aminoacids with respect to the larger P210 protein so far identified. The hematologic phenotype expressed by the two patients carrying this unusual type of Bcr/Abl rearrangement does not significantly differ from that commonly seen in chronic myelogenous leukemia.
Assuntos
Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Proteínas Tirosina Quinases , Sequência de Aminoácidos , Sequência de Bases , Mapeamento Cromossômico , Cromossomos Humanos Par 22 , Éxons , Rearranjo Gênico/genética , Genes abl/genética , Humanos , Dados de Sequência Molecular , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcrRESUMO
Five patients with lymphoid blastic transformation of chronic myeloid leukemia have been treated with IL2 associated with Vincristine (VCR) plus Prednisone (PDN). Our study indicates that IL2 may be employed in the management of this disease without excessive toxicity at the higher doses in hospitalized patients and at the lower doses as outpatients. Concerning the therapeutic efficacy, our preliminary results indicate that IL2 might be useful in enhancing the chemosensitivity of the leukemic blasts. It remains to be seen if this will result in a rapid return to the CP and in a prolongation of survival.
Assuntos
Crise Blástica/terapia , Fatores Imunológicos/uso terapêutico , Interleucina-2/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Crise Blástica/tratamento farmacológico , Transplante de Medula Óssea , Terapia Combinada , Avaliação de Medicamentos , Feminino , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prednisona/administração & dosagem , Vincristina/administração & dosagemAssuntos
Fatores Estimuladores de Colônias/administração & dosagem , Substâncias de Crescimento/administração & dosagem , Fatores Estimuladores de Colônias/uso terapêutico , Avaliação de Medicamentos , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Substâncias de Crescimento/uso terapêutico , Humanos , Infusões Intravenosas , Injeções Subcutâneas , Leucócitos/efeitos dos fármacos , Neoplasias/tratamento farmacológicoAssuntos
Interleucina-2/uso terapêutico , Leucemia Mieloide Aguda/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Medula Óssea/imunologia , Medula Óssea/patologia , Ensaios Clínicos como Assunto , Humanos , Imunoterapia , Interleucina-2/efeitos adversos , Células Matadoras Ativadas por Linfocina/imunologia , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Trombocitopenia/etiologiaAssuntos
Doenças da Medula Óssea/terapia , Fatores Estimuladores de Colônias/farmacologia , Substâncias de Crescimento/farmacologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Animais , Fatores Estimuladores de Colônias/efeitos adversos , Fatores Estimuladores de Colônias/uso terapêutico , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Granulócitos/citologia , Substâncias de Crescimento/efeitos adversos , Substâncias de Crescimento/uso terapêutico , Hematopoese/efeitos dos fármacos , Células-Tronco Hematopoéticas/citologia , Humanos , Fatores Imunológicos/uso terapêutico , Macrófagos/citologia , Camundongos , Camundongos Transgênicos , Neoplasias/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Receptores de Superfície Celular/efeitos dos fármacos , Receptores de Fator Estimulador de ColôniasRESUMO
Granulocyte-macrophage colony-stimulating factor (GM-CSF) was given for three days (8 micrograms/kg/day) to 14 subjects who had solid tumors and normal hemopoiesis. The treatment induced a rapid 3- to 5-fold increase in the number of circulating neutrophils, eosinophils and monocytes. Lymphocytes, platelets and reticulocytes were unmodified during treatment. Activation of circulating neutrophils during GM-CSF treatment was demonstrated by a significant, increased release of neutrophil-derived platelet-activating factor after stimulation with N-formyl-methionyl-leucyl-phenylalanine, tumor necrosis factor-alpha or phagocytosis. The granulomonocytosis was dependent on increased bone marrow production of mature cells. Using the thymidine suicide technique, we observed that GM-CSF more than doubled the percentage of granulocyte-macrophage and megakaryocyte colony-forming units (CFU-gm and CFU-meg) and erythroid burst-forming units (BFU-e) in the S phase of the cell cycle. However, at the level of morphologically recognizable cells with autoradiography, we observed that GM-CSF increased the labeling index of the granulo-monopoietic cells, whereas that of the erythroblasts was unchanged. These data suggest that in accordance with in vitro observations, GM-CSF exerts its activity through all granulo-monopoietic lineages, whereas other cytokines (erythropoietin, thrombopoiesis-stimulating factors) may be needed to fully exploit the proliferative stimulus of GM-CSF on BFU-e and CFU-meg. After treatment discontinuation, the proliferative activity drops to values lower than before treatment, suggesting a period of relative refractoriness of marrow progenitors to the cytocidal effect of cell cycle-specific antineoplastic agents. This hypothesis is under evaluation in a controlled clinical trial where GM-CSF is given prior to chemotherapy.
Assuntos
Fatores Estimuladores de Colônias/uso terapêutico , Substâncias de Crescimento/uso terapêutico , Hematopoese/efeitos dos fármacos , Leucemia/tratamento farmacológico , Transplante de Medula Óssea , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Humanos , Cinética , Leucemia/terapia , Contagem de Leucócitos , Neutrófilos/efeitos dos fármacosRESUMO
The pattern of immunoglobulin (Ig) gene rearrangement and the genomic structure of the Myc locus were investigated in the DNA of 20 lymphnode biopsies of patients suffering from lymphoadenopathy-associated syndrome (LAS) and from 3 patients with Burkitt's lymphoma. Although polyclonality was the prevalent pattern of Ig gene rearrangement observed in LAS, in 30% of the cases discrete bands of Ig heavy chain gene rearrangement were identifiable due to the presence of monoclonal or oligoclonal cell populations. However, structural alterations of the Myc gene were not detected in any cases. As expected, in all three Burkitt's lymphomas studied, the lymphnode DNA displayed a clonal pattern of Ig heavy chain gene rearrangement. The Myc was altered in two cases, which presented a truncation of the gene beginning within a very short region of the first intron. By contrast, the breakpoint positions on chromosome 14 mapped in different regions of the Ig loci, which in both cases involved the switch (SH) area. Data confirm the relatively common occurrence of oligoclonal expansions within B cells in LAS and the frequent involvement of the Myc oncogene in the process of lymphomagenesis in individuals positive for human immunodeficiency virus (HIV).