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It is well established that natural killer (NK) cells play an important role in the immunity against cancer, while the involvement of other recently identified, NK-related innate lymphoid cells is still poorly defined. In the haploidentical hematopoietic stem cell transplantation for the therapy of high-risk leukemias, NK cells have been shown to exert a key role in killing leukemic blasts residual after conditioning. While the clinical results in the cure of leukemias are excellent, the exploitation of NK cells in the therapy of solid tumors is still limited and unsatisfactory. In solid tumors, NK cell function may be inhibited via different mechanisms, occurring primarily at the tumor site. The cellular interactions in the tumor microenvironment involve tumor cells, stromal cells and resident or recruited leukocytes and may favor tumor evasion from the host's defenses. In this context, a number of cytokines, growth factors and enzymes synthesized by tumor cells, stromal cells, suppressive/regulatory myeloid and lymphoid cells may substantially impair the function of different tumor-reactive effector cells, including NK cells. The identification and characterization of such mechanisms may offer clues for the development of new immunotherapeutic strategies to restore effective anti-tumor responses. In order to harness NK cell-based immunotherapies, several approaches have been proposed, including reinforcement of NK cell cytotoxicity by means of specific cytokines, antibodies or drugs. These new tools may improve NK cell function and/or increase tumor susceptibility to NK-mediated killing. Hence, the integration of NK-based immunotherapies with conventional anti-tumor therapies may increase chances of successful cancer treatment.

Meningioma 1 (MN1) gene overexpression has been reported in acute myeloid leukaemia (AML) patients and identified as a negative prognostic factor. In order to characterize patients presenting gene overexpression and to verify if MN1 transcript could be a useful marker for minimal residual disease detection, MN1 was quantified in 136 AML patients with different cytogenetic risk and in 50 normal controls. In 20 patients bearing a fusion gene transcript suitable for minimal residual disease quantitative assessment and in 8 patients with NPM1 mutation, we performed a simultaneous analysis of MN1 and the fusion-gene transcript or NPM1 mutation during follow-up. Sequential MN1 and WT1 analysis was also performed in 13 AML patients lacking other molecular markers. The data obtained show that normal cells consistently express low levels of MN1 transcript. In contrast, high levels of MN1 expression are present in 47% of patients with normal karyotype and in all cases with inv(16). MN1 levels during follow-up were found to follow the pattern of other molecular markers (fusion gene transcripts, NPM1 and WT1). Increased MN1 expression in the BM during follow up was always found to be predictive of an impending hematological relapse.

Aim. To study the deposition of donor platelets (DP) in myelosuppressive thrombocytopenia (TP) in patients with acute leukemia (AL) or lymphosarcoma (LSA), by using a radionuclide label (51Cr) for DP. Subjects and methods. Complex clinical, hematological and radionuclide studies were conducted in 63 patients divided into 3 groups: 1) 7 healthy volunteers (a control group); 2) 37 patients with AL; 3) 19 patients with LSA. Results. Changes were found in the deposition of labeled DPs used to prevent and treat hemorrhagic syndrome in myelosuppressive TP in patients with AL or LSA. In AL, this function was established to be virtually completely suppressed whereas in LSA, some functional activity of mononuclear phagocytes was preserved. Different degrees of suppression of this function were probably related to the nature of these diseases and particularly due to varying degrees of leukemic infiltration of depot organs. A mechanism for increased consumption of transfused DP in profound TP, one of the causes of which is the myelosuppression as a result of programmed polychemotherapy, cannot be ruled out. Conclusion. By and large, the radionuclide labeling technique for DP may be useful in specifying a number of uncertain mechanisms for derangements of the thrombocytic component of hemostasis in oncohematologic diseases.

NPM mutations are the most common genetic abnormalities found in non-promyelocytic AML. NPM-positive patients usually show a normal karyotype, a peculiar morphologic appearance with frequent monocytic traits and good prognosis in the absence of an associated FLT3 mutation. This report describes the immunophenotypic and genetic characteristics of a consecutive series of NPM-mutated de novo AML patients enroled in the CETLAM trial. Eighty-three patients were included in the study. Complete immunophenotype was obtained using multiparametric flow cytometry. Associated genetic lesions (FLT3, MLL, CEBPA and WT1 mutations) were studied by standardized methods. Real-time PCR was employed to assess the minimal residual status. The most common pattern was CD34-CD15+ and HLA-DR+. Small CD34 populations with immunophenotypic aberrations (CD15 and CD19 coexpression, abnormal SSC) were detected even in CD34 negative samples. Nearly all cases expressed CD33 (strong positivity), CD13 and CD117, and all were CD123+. The stem cell marker CD110 was also positive in most cases. Biologic parameters such as a high percentage of intermediate CD45+ (blast gate) (> 75% nucleated cells), CD123+ and FLT3-ITD mutations were associated with a poor outcome. Quantitative PCR positivity had no prognostic impact either after induction or at the end of chemotherapy. Only PCR positivity (greater than 10 copies) detected in patients in haematological remission was associated with an increased relapse rate. Further studies are required to determine whether the degree of leukemic stem cell expansion (CD45 + CD123 + cells) increases the risk of acquisition of FLT3-ITD and/or provides selective advantages. (C) 2010 Elsevier Ltd. All rights reserved.

Hematopoietic stem cells (HSCs) balance self-renewal and differentiation in order to sustain lifelong blood production and simultaneously maintain the HSC pool. However, there is clear evidence that HSCs are subject to quantitative and qualitative exhaustion. In this review, we briefly discuss several known aspects of the stem cell aging process, including DNA damage, telomere shortening, and oxidative stress. Besides these known players, there is increasing evidence that higher order chromatin structure, largely defined by the histone code and affecting transcriptional activity, is important. A model is suggested which describes how epigenetic regulation of gene transcription by modulation of the chromatin structure in stem cells can account for regulation of the aging program.

Hematopoietic stem cells (HSCs) balance self-renewal and differentiation in order to sustain lifelong blood production and simultaneously maintain the HSC pool. However, there is clear evidence that HSCs are subject to quantitative and qualitative exhaustion. In this review, we briefly discuss several known aspects of the stem cell aging process, including DNA damage, telomere shortening, and oxidative stress. Besides these known players, there is increasing evidence that higher order chromatin structure, largely defined by the histone code and affecting transcriptional activity, is important. A model is suggested which describes how epigenetic regulation of gene transcription by modulation of the chromatin structure in stem cells can account for regulation of the aging program.

Natural Killer (NK) cells are major effector cells of the innate immunity. The discovery, over two decades ago, of major histocompatibility complex-class I-specific inhibitory NK receptors and subsequently of activating receptors, recognizing ligands expressed by tumor or virus-infected cells, paved the way to our understanding of the mechanisms of selective recognition and killing of tumor cells. Although NK cells can efficiently kill tumor cells of different histotypes in vitro, their activity may be limited in vivo by their inefficient trafficking to tumor lesions and by the inhibition of their function induced by tumor cells themselves and by the tumor microenvironment. On the other hand, the important role of NK cells has been clearly demonstrated in the therapy of high risk leukemias in the haploidentical hematopoietic stem cell (HSC) transplantation setting. NK cells derived from donor HSC kill leukemic cells residual after the conditioning regimen, thus preventing leukemia relapses. In addition, they also kill residual dendritic cells and T lymphocytes, thus preventing both GvH disease and graft rejection.

Background In Cote d’Ivoire, acute leukemias account for 12.5% of hematological malignancies. Acute leukemias are due to an anomaly of the stem cell characterized among other things by the expression of CD34 + CD38 - surface markers. This CD34 + CD38 - phenotype as well as other factors such as tumor syndrome, high leukocytosis and blasts are considered as important factors of poor prognosis. We therefore proposed to investigate the prognostic value of the expression of CD34 + CD38 - markers in acute leukemias in Abidjan. Methods We selected 23 patients aged 33 years on whom we performed Complete Blood Count, bone marrow aspiration and immunophenotyping. To search for myeloperoxydase, smears of blood or bone marrow were stained with benzidine and revealed by the use of Hydrogen peroxide. Acute leukemias were then identified and distributed using the score proposed by the European Group for the Immunological characterization of Leukemias. The definitive diagnosis was made by combining morphological characters that serve as the basis for the French-American-British classification as well as cytochemical and immunophenotypic characters. Results According to the cytological and immunophenotypic classifications, the acute lymphoid leukemia 2 and B IV predominated. 52.2% (12/33) of patients were CD34 + CD38 - . This phenotype was found in almost all cytological immunophenotypic types. The medullary invasion by blasts (reflection of the tumor mass) of the total sample of CD34 + , CD34 + CD38 - patients and those not expressing CD34 + was respectively 79.4%, 81.25%, 83.3% and 74.8%. Conclusion There was therefore no correlation between medullary blasts and the expression of CD34 + CD38 - . To the factors we selected it would have been necessary to associate the study ofcytogenetic and molecular anomalies to better understand the role of CD34 + CD38 - phenotype, concerning prognosis.

Bone Marrow and Acute Leukemias - WORKSHOP...

FLT3 is a tyrosine kinase (TK), member of the class III TK receptor family, normally expressed in hematopoietic, immune and neural systems, also playing an important role in the pathogenesis of acute leukemias, particularly acute myeloid leukemia (AML), where it is present in constitutively activated mutated forms, correlated with poor prognosis, in a notable percentage of patients. For these reasons FLT3 soon appeared as a promising target for the therapeutic intervention for this severe and aggressive malignancy; the recent determination of the crystal structure of the autoinhibited form of FLT3 gave new trend for the design and the synthesis of potent inhibitors. Small molecules tyrosine kinase inhibitors represent one of the largest drug family currently targeted by pharmaceutical companies for the treatment of cancer. Exciting examples of such molecules have reached advanced clinical trials and have been recently approved by FDA for the treatment of different solid or haematological tumors. Usually TK inhibitors share common features, namely two hydrophobic/aromatic regions bearing one or more hydrogen bonding substituents. These two regions can be connected by different spacers and almost all the molecules contain a component resembling the ATP purine structure. This review will deal with FLT3 synthetic inhibitors, reporting not only the most important molecules that are in clinical trials, but also the new compounds that have appeared in literature in the last few years. Our attention will be focused on chemical structures, mechanisms of action and structure-activity relationships.

Texto completo: acesso restrito. p. 622-626 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2014-01-21T11:18:29Z No. of bitstreams: 1 00043426-200709000-00009.pdf: 131072 bytes, checksum: e72f51ce46def6b00e814444cabe8870 (MD5) Made available in DSpace on 2014-01-21T11:18:29Z (GMT). No. of bitstreams: 1 00043426-200709000-00009.pdf: 131072 bytes, checksum: e72f51ce46def6b00e814444cabe8870 (MD5) Previous issue date: 2007 Objective: This study was to determine the prevalence and characteristics of the osteoarticular manifestations on initial clinical presentation of acute leukemias (ALs) on childhood in the state of Bahia, Brazil. Materials and Methods: This retrospective study assessed the medical records of 406 patients with AL from January 1995 to December 2004. Results: Acute lymphocytic leukemia (ALL) was diagnosed in 313 (77.1%) patients and acute myeloid leukemia (AML), in 93 (22.9%) patients, including 241 males (59.4%) and 165 females (40.6%). Age ranged from 9 months to 15 years (average: 6.18 y). The most common presenting features were fever (18.5%), musculoskeletal diffuse tenderness (15.0%), pallor (11.4%), and leg tenderness (5.7%). Prior referral to our center, the most frequent initial diagnosis was anemia (15.8%), leukemia (15.0%), amygdalitis (3.7%), and rheumatic fever (2.7%). Osteoarticular manifestations were found on 54.7% of the patients with AL, with a higher frequency among patients between 1 and 9 years of age (58.7%, P=0.0007). The presence of joint tenderness (16.2% in ALL×5.4% in AML), arthritis (26.6% in ALL×9.7 in AML), bone tenderness (26.1% in ALL×16.1% in AML), limb tenderness (49.5% in ALL×25.8% in AML), and antalgic gait (32.8% in ALL×9.7% in AML) had higher prevalence on ALL. The large joints, chiefly the knees (10.6%), ankles (9.4%), elbows (4.4%), and shoulders (3.6%) were more often affected. Conclusions: AL should be considered on the differential diagnosis of osteoarticular symptoms of unknown etiology in children.

Unsere Untersuchungen belegen, dass nichtmyeloablative Stammzelltransplantationen (NST) bei Patienten mit Hochrisiko-ALL oder -AML eine neue therapeutische Option darstellen. Die NST ermöglichte eine allogene Stammzelltransplantation bei Transplantationskandidaten mit Kontraindikationen gegen eine hochdosierte Strahlen- und Chemotherapie (Standardtransplantation). Nach NST kam es häufig zur Entwicklung von Infektionen und einer spät auftretenden akuten Transplantat-gegen-Wirt Reaktion (GvHD), diese waren aber mit einer geringeren Mortalität verbunden. Das erkrankungsfreie Überleben und das Gesamt-Überleben nach NST und nach Standardtransplantation waren fast gleich. Der höheren Rezidivrate nach NST stand eine höhere transplantationsassoziierte Mortalität nach Standardtransplantation gegenüber. Das Konditionierungsregime selber war ohne Einfluss auf das Überleben der Patienten. Sequenzielle Chimärismusuntersuchungen von Leukozytensubpopulationen erlaubten eine frühe Diagnose eines gemischten Chimärismus, der einen prädiktiven Wert für das Auftreten eines Rezidivs hatte. Ein stabiler gemischter Chimärismus wurde nicht beobachtet. Durch eine adoptive Immuntherapie mit Spenderlymphozyten (DLI) konnte bei der Mehrzahl der transplantierten Patienten mit gemischtem Chimärismus eine Chimärismuskonversion und eine lang anhaltende komplette Remission induziert werden, ein wichtiger Hinweis auf einen Transplantat-gegen-Leukämie Effekt (GvL) der Spenderzellen. Durch die NST rückt der immunologische Effekt der Transplantation gegenüber der Zytoreduktion bei der Standardtransplantation stärker in den Vordergrund. Unsere Ergebnisse sprechen für die Wirksamkeit eines GvL-Effektes bei akuten Leukämien auch nach NST. Die Erfahrungen mit der NST bei akuten Leukämien haben zu einer Anwendung bei refraktären Nierenzellkarzinomen geführt. Eine Tumorregression wurde erst nach Chimärismuskonversion und/oder Entwicklung einer GvHD beobachtet; diese Befunde sind vereinbar mit einem Transplantat-gegen-Tumor Effekt (GvT). Die transplantationsassoziierte Morbidität war allerdings bei diesen meist älteren Patienten erheblich. Die Therapie sollte ausschließlich im Rahmen klinischer Studien erfolgen, da es sich nach wie vor um ein experimentelles Therapieverfahren handelt. Die Analyse minimal residueller Erkrankung und der Einsatz hochauflösender Chimärismusuntersuchungen von Leukozytensubpopulationen sollte die Bedeutung des gemischten Chimärismus weiter klären und zu einem gezielteren Einsatz von DLI führen. Prospektive vergleichende Studien müssen in naher Zukunft den Stellenwert der NST untersuchen., Our clinical investigations demonstrate, that nonmyeloablative stem cell transplantation (NST) is a novel therapeutic option in patients with high-risk ALL or AML. NST can be administered to patients eligible for allogeneic stem cell transplantation with contraindications against high-dose radio- and chemotherapy (standard SCT). After NST, infections and late onset acute graft-versus-host disease (GvHD) frequently occurred, but transplant-related mortality was low in contrast to standard SCT. Leukemia-free survival and overall survival were similar after NST and standard SCT. A higher relapse rate after NST was balanced by a higher transplant-related mortality after standard SCT. The conditioning regimen itself had no relevant impact on survival. Sequential chimerism analyses of leukocyte subpopulations resulted in early diagnosis of mixed chimerism, which proved to be predictive for later relapses. Stable mixed chimerism was not established in these patients. Adoptive immunotherapy in patients, who were in hematologic remission but had mixed chimerism after transplantation, induced conversion to complete donor chimerism and long-lasting complete remissions in the majority of patients, a strong hint to a graft-versus-leukemia-effect (GvL) of donor T-lymphocyte infusions. A change in the character of stem cell transplantation was achieved by NST with a shift from the predominantly cytoreductive effect of standard SCT towards an emphasis on the immunologic GvL-effect. Our results demonstrated the efficacy of a GvL-effect in acute leukemias after NST. The experiences with NST in acute leukemias have prompted studies in patients with refractory advanced renal cell cancer. Tumor regressions were observed only after chimerism conversion and / or development of GvHD, these results being compatible with a graft-versus-tumor effect (GvT). However, transplant-related morbidity was substantial in these mostly elderly patients. Therapy within clinical studies is mandatory, because allogeneic stem cell transplantation still has to be regarded an experimental procedure in these patients. The analysis of minimal residual disease and application of high-resolution chimerism analysis of leukocyte subpopulations by microarrays could lead to a more profound understanding of mixed chimerism and to a more rational use of DLI in the near future. Prospective randomized trials should be conducted to evaluate the role of NST.

La citometría de flujo (CMF) es una técnica de avanzada, altamente sensible y automatizada, que se emplea para el inmunofenotipaje de las células normales y leucémicas. En este artículo se muestran los principales aspectos metodológicos a tener en cuenta para un mejor desarrollo e interpretación del inmunofenotipo por CMF, entre los que se encuentran: tipo, cantidad, conservación y transportación de la muestra, uso de anticoagulantes, empleo de anticuerpos monoclonales y fluorocromos, lisado de hematíes, fijación celular, así como la calibración y compensación de la auto-fluorescencia. Finalmente, se exponen las principales aplicaciones de esta metodología para definir el estado de maduración celular leucémico, clasificar las leucemias agudas en distintos subtipos inmunológicos, identificar subgrupos de mal pronóstico y detectar fenotipos aberrantes. Todo lo anterior resulta de gran utilidad para el diagnóstico de la enfermedad mínima residual que permite estratificar a los pacientes en diferentes grupos de riesgo e individualizar el tratamiento antileucémico.

Aim. To perform a dynamic study of Β-endorphin, hypoxia-inducible factor-1α (HIF-1α), and cytokines in hematologic patients. Subjects and methods. Fifty-nine patients with different types of acute leukemia (AL), 30 with anaplastic anemia (AA), 24 with thrombocytopenic purpura, and 20 healthy volunteers were examined during their 40-day stay at 3200 m above sea level. Β-Endorphin and HIF-1α were measured by a sandwich-type enzyme immunoassay using the Abcam antibodies. Cytokines (interleukin (IL)-2, IL-6, and tumor necrosis factor-α) were estimated by enzyme immunoassay applying the Pro Con kits (Saint Petersburg). Results. Serum Β-endorphin concentrations were 1.5-2-fold above the normal values in the majority of patients with AL. The patients with initial leukocytosis at onset of disease were noted to have elevated white blood cell Β-endorphin concentrations up to 85.9±22.4 pg/ml; moreover, during chemotherapy this index increased about two times (170.74±33.8 pg/ml). There was a direct correlation between the concentrations of Β-endorphin and HIF-1α (r = 0.9) and an inverse correlation between the levels of IL-6 and Β-endorphin (r = -0.7). On ascending to 3200 m, under the conditions of hypoxic hypoxia the patients with AA or idiopathic thrombocytopenic purpura showed a considerable increase in serum Β-endorphin concentrations, mainly in the acute period of being at high altitudes. Conclusion. Stress factors (tumor, use of cytostatics, pain, anemia, hypoxia, high environment temperature) stimulate the elaboration of Β-endorphin, particularly in the white blood cells of patients with AL during chemotherapy. The highest elevation in the index was seen during acute adaptation to hypoxic hypoxia.

Introduction: Despite all improvement in the treatment of acute myeloid leukemia (AML) patients, the management in relapsed or refractory disease is still controversial. The use of multiple chemotherapeutic agents will induce more toxicity and morbidity in patients. Fludarabin- containing therapy (FLAG and FLANG) mostly has been used in the treatment of relapsed or refractory AML patients. Methods: In this retrospective study, we evaluated the response of treatment in 40 adult leukemia patients treated with these regimens from October 2007 to December 2011 in our center. They took FLAG (fludarabine, cytarabine, GCSF) and FLANG (fludarabine, cytarabine, mitoxantrone) according to the approved protocol. They were taken packed cells or platelets as needed and antibiotics in cases of established or highly suspicious infections. After these therapies, 12 patients with suitable donor made ready for allogeneic hematopoietic stem cell transplantation (HSCT) and one patient without donor underwent autologous HSCT. Results: The median age of patients was 29.5 (range: 16- 50) years old. The male to female ratio was 30:10. The patients were diagnosed with ALL (15, 37.5%) and AML (25, 62.5%). The most common subtype of leukemia was ALL- L2 and AML- M4. The most common disease treated was AML-M4. Two patients had secondary leukemia (breast cancer and MDS). Except two patients which treated with FLAG regimen, others received FLANG. Most patients were primary refractory (18, 45%), first relapse (17, 42.5%) or second relapse (5, 12.5%) before this treatment. Thirteen patients underwent hematopoietic stem cell transplantation after FLANG. Four patients received FLANG as relapse treatment after transplantation. Pulmonary aspergillus infection occurred in 13 patients and aspergillus sinusitis in two after FLANG/ FLAG treatment. White blood cells and platelet recovery observed in 30 patients with a median time of 20 days after treatment. Treatment resulted in complete response (n=19), partial response (n=1) and no response (n=11) in patients. Early death (before 60 days) after treatment occurred in 9 (22.5%) patients. The most common causes of death were primary disease (relapse) (24, 60%) and infection (5, 12.5%). The one- year overall survival was 21.4% (SE: 7.1%). Among the survivors, only 5 patients received transplantation and 5 patients are alive without transplantation. Conclusion: The study shows that refractory and relapsed leukemia patients can achieve complete remission with FLAG/ FLANG treatment. The side effects include serious fungal infections and sepsis. Moreover, high mortality during these treatments was observed.

Aim. To analyze the causes of prolonged hematopoietic tissue aplasias in patients with acute leukemias (AL) after chemotherapy courses. Materials and methods. Data on 7 patients with acute myeloid leukemia, followed up at the Hematology Departments, Hematology Research Center, Russian Academy of Medical Sciences, over the period 2003 to 2007, who had developed deep bone marrow aplasia (BMA) inadequate to cytostatic drug exposure during chemotherapy, were analyzed. The authors compared in all the patients the values of peripheral blood and bone marrow (BM) puncture specimens and the results of blood tests using the polymerase chain reaction at different AL development stages with the results of an immunohistochemical study using the markers of viruses of hepatitis C and B, a herpes group (EBV, CMV, HSV-1, HSV-2) and parvovirus B19. Results. The marker of hepatitis C was detected in 6 of the 7 patients with prolonged BMA; 3 of these 6 patients showed a simultaneous infection with hepatitis B. Six of the 7 patients were found to have concomitant BM lesion with various herpes group viruses. Two patients had a resistant form of AL. Conclusion. Hepatitis C virus infection in patients and the resistant form of the disease were the principal causes of the development of BMA inadequate to cytostatic drug exposure. Affliction of abundant bone marrow cells with herpes group viruses was not a direct cause, but might substantially aggravate BMA.

Aim. To study the pattern of complex chromosome damages (CCD) in acute leukemias (AL) and their place in the development of post-transplant recurrences (PTR) of AL. Materials and methods. Cytogenetic and partially molecular biological studies of bone marrow cells were conducted in 10 patients with PTR. Of them, 6 patients were diagnosed as having acute lymphoblastic leukemia (ALL), including T-ALL and Ph-positive ALL in 2 and 4 patients, respectively; and 4 patients had acute non-lymphoblastic leukemia (ANLL), including one case secondarily induced by previous polychemotherapy (PCT) and irradiation. The standard G-band staining technique complemented by multicolor fluorescence in situ hybridization in one of the cases was used. Results. It was shown that CCD had the similar pattern in 4 patients before transplantation and in PTR, progressed in 4 more patients, was absent or unnoticed in the early stage of the disease. The other recurrent chromosomal abnormalities that are worthy of notice are as follows: a) the presence of two Ph chromosomes in the cells of two of the 4 patients with Ph+ ALL; b) the frequent involvement of chromosome pairs 9, 19, 5, and 7 into the numerical and structural rearrangements. Conclusion. The important feature of PTR of AL is cellular CCDs, a portion of which is clearly related to previous PCT and may be of pathogenetic value for the development of recurrences.