ALBERT

Description: T-cell prolymphocytic leukemia (T-PLL) is a poor-prognostic neoplasm. Differentiation stage and immune-effector functions of the underlying tumor cell are insufficiently characterized. Constitutive activation of the T-cell-leukemia-1A (TCL1A) oncogene distinguishes the (pre)leukemic cell from regular post-thymic T-cells. We assessed here activation-response patterns of the T-PLL lymphocyte and interrogated the modulatory impact by TCL1A. Immunophenotypic and gene expression profiles revealed a unique spectrum of memory-type differentiation of T-PLL with predominant central-memory stages and frequent non-canonical patterns. Virtually all T-PLL expressed a T-cell receptor (TCR) and/or CD28-coreceptor without overrepresentation of specific TCR-clonotypes. The highly activated leukemic cells also revealed losses of negative-regulatory TCR-coreceptors (e.g. CTLA4). TCR-stimulation of T-PLL cells evoked higher-than-normal cell-cycle transition and profiles of cytokine release that resembled those of normal memory T-cells. More activated phenotypes and higher TCL1A correlated with inferior clinical outcomes. TCL1A was linked to T-PLL's marked resistance to activation- and FAS-induced cell death. Enforced TCL1A enhanced phosho-activation of TCR-kinases, second-messenger generation, and JAK/STAT or NFAT transcriptional responses. This reduced the input thresholds for IL-2 secretion in a sensitizer-like fashion. Mice of TCL1A-initiated protracted T-PLL development resembled such features. When equipped with epitope-defined TCRs or CARs, these Lckpr-hTCL1Atg T-cells gained a leukemogenic growth advantage in scenarios of receptor stimulation. Overall, we propose a model of T-PLL pathogenesis in which TCL1A enhances TCR-signals and drives accumulation of death-resistant memory-type cells that utilize amplified low-level stimulatory input and whose loss of negative coregulators additionally maintains their activated state. Treatment rationales are provided by combined interception in TCR- and survival signaling.

Description: Key Points AML induction with liposomal daunorubicin (80 mg/m2 per day for 3 days) shows antileukemic activity comparable to idarubicin (12 mg/m2 per day for 3 days). Liposomal daunorubicin promises to be more active in the t(8;21) subgroup and causes less treatment-related toxicity.

Description: To study transplanted unperturbed and mobilized long-term hematopoiesis after selection with an alkylating agent, bone marrow (BM) from 5 C57BL/6J mice was pooled, repeatedly transduced with retroviruses encoding the alkylating agent resistance protein O6-Methylguanine-DNA and enhanced green fluorescent protein (eGFP) as an easily traceable marker. Between 1 to 9x105 transfected BM cells were transplanted into 15 myeloablatively irradiated sex-mismatched C57BL/6J mice. Subsequently, 3 to 4 selection rounds with BCNU/O6-BG were carried out, enriching eGFP marked hematopoiesis in these mice up to 70–90%. Between 1 and 7x107BM cells of different mice were transplanted according to marrow location into groups of 5 sex-matched Bri44[1] mice. Two mice each received BM from the hind limbs, two from the pelvis and one received cells from the spleen, only, respectively. Altogether the study comprised 15 groups divided into 6 female and 9 male groups. Of these, 4 male and 3 female groups received 3 HSC-mobilization courses with G-CSF at intervals of 2 months starting 3 month after transplantation. Hematopoiesis in the other fraction remained unperturbed. During the observation period of 11–14 months in these tertiary recipients, repeated FACS analyses as well as linear amplification mediated (LAM) PCRs were carried out to track the clonal contributions. A decrease in the percentage of eGFP expressing marked hematopoiesis was observed in most cases. However, eGFP expression never disappeared altogether and could still be detected in the different hematopoietic lineages and successfully sorted for further analyses by MoFlo (Dako-Cytomation). Assessment of the clonal status of the Bri44 by LAM-PCR displayed interesting results. In some mice a decline in clone numbers was observed, whereas clone numbers remained stable in others. Tertiary transplantation with long-term follow-up indicates that this observation may be related to the transplantation of limited long-term repopulating clone numbers and progenitor cell exhaustion over time.

Description: Abstract 2741 Cytogenetic analyses are essential for stratification and prognosis in childhood AML. We analysed the frequency of chromosomal aberrations and the outcome according to the cytogenetic findings in 386 patients with data (92%) out of the total group of 422 German patients in study AML-BFM 2004. The aim was to evaluate the prognostic impact of specific chromosomal aberrations in a large cohort of patients treated according to this BFM protocol. Patients were

Description: Although the therapy of Hodgkin lymphoma has improved, patients still suffer from late toxicities and insufficient treatment of relapses. Hence, new treatment strategies are needed. Statins are used to treat hypercholesterolaemia and prevent cardiovascular disease. There is evidence for a preventive effect of statins in cancer, including lymphoma. So far, nothing is known about a therapeutic activity of statins or related drugs in Hodgkin lymphoma. Statins block the conversion of 3-hydroxy-3-methylglutaryl-coenzyme A to downstream isoprenoid products like farnesyl and geranylgeranyl-pyrophosphate, inhibiting protein prenylation and leading to apoptosis in several malignancies. The anti-tumour activity of the statin simvastatin and three specific prenylation inhibitors (FTI-277, GGTI-298 and tipifarnib) in Hodgkin lymphoma cells was evaluated in cytotoxicity and apoptosis assays. Furthermore, simvastatin was tested in a xenograft model for human Hodgkin lymphoma. First simvastatin induced caspase-related apoptosis in Hodgkin lymphoma cells via the isoprenoid pathway. The IC50 of simvastatin in cytotoxicity assays was 〈 2 μM. Second simvastatin showed high activity in a mouse model for Hodgkin lymphoma, delaying tumour establishment and inhibiting tumour growth. Finally the geranylgeranyltransferase inhibitor GGTI-298 and the farnesyltransferase inhibitors FTI-277 and tipifarnib displayed anti-tumour activity in Hodgkin lymphoma cells (approximate IC50 in cytotoxicity assays: 20, 7.5 and 〈 0.1 μM respectively). Importantly, the concentration of simvastatin that induced apoptosis in Hodgkin lymphoma cells was in the range of 2 μM. This corresponds to plasma levels reached in humans in clinical trials with high dose statins in cancer. Thus, our results suggest two possible applications of simvastatin in Hodgkin lymphoma: First simvastatin in high doses could be included in polychemotherapy regimens to improve the remission rate of relapsed patients. Second simvastatin in the cholesterol-lowering dose should be evaluated as a preventive drug for patients in remission to avoid relapses. Moreover, in comparison to other haematological malignancies, the farnesyltransferase-inhibitor tipifarnib was highly cytotoxic in Hodgkin lymphoma cells. Given its activity in clinical trials in haematological neoplasia, its clinical evaluation in Hodgkin lymphoma is warranted. Taken together, prenylation inhibitors are promising drugs for the treatment of Hodgkin lymphoma.

Description: Background: Hemophilia is a bleeding disorder associated with frequent hemarthroses and ensuing debilitating arthropathies. Patients with hemophilia (PWH) are encouraged to participate in low impact physical activities to improve joint health, mobility, and quality of life (QoL). However, activities such as walking, swimming or physical therapy are often perceived as "boring", which results in participation in high risk activities that may cause injury or bleeding. Indoor therapeutic rock climbing is practiced successfully to improve physical and psychological well-being in patients with neuromuscular disorders, and may be a "fun" alternative for PWH. The aim of this study was to investigate the safety of therapeutic rock climbing and its effects on joint health for PWH with arthropathies. Methods: Twelve adult male patients (median age 31 years, IQR=24,41) with moderate to severe hemophilia A and arthropathies (defined by decreased normative range of motion (ROM)) were recruited from the Hemophilia Treatment Centers at University of California, San Diego, USA (UCSD) and Ludwig Maximilians University, Munich, Germany (LMU)). All participants completed 12 sessions of individually tailored indoor top rope rock climbing, instructed by a climbing coach and physical therapist. Functional and clinical joint status including ROM, Hemophilia Joint Health Score (HJHS) for elbows, knees, and ankles (n=12), climbing skills (UCSD: Yosemite Decimal Scale; LMU: Union Internationale des Associations d'Alpinisme scale), QoL measures (UCSD: Haem-A-Qol, Hep-Test-Q; LMU: Hemo-Qol-A), annual bleed rate (ABR), and clotting factor consumption were assessed in both cohorts (UCSD n=6; LMU n=6) pre and post climbing. Additionally, effects on cartilage health, joint inflammation and soft tissue hypertrophy were assessed by musculoskeletal ultrasound and power doppler (MSKUS/PD) in the UCSD cohort. Descriptive statistics and Wilcoxon matched-pairs signed-rank tests were used for data analysis. Data are expressed as median and inter-quartile range; p-values ≤ 0.05 were considered significant. Results: Compared to baseline, HJHS improved significantly after completion of the program (16.5 [IQR=6.0, 28.5] post vs 17.5 [6.0, 35.0] pre; n=12; p = 0.03). A significant increase in dorsiflexion was evident in arthropathic ankles (0 degrees [IQR= -4, 4] post vs -4 [IQR-10, -3] pre; n = 9; p

Description: The platelets of 11 patients with Glanzmann's thrombasthenia and their nearest family members were studied for the expression of the platelet- specific alloantigens of the Zw-, Ko- and Bak systems. The strength of the expression of the Zwa antigen was diminished on the platelets of 3 patients, and the antigen was absent from the platelets of the other 8. The platelets of none of the patients reacted with anti-Zwb serum. Therefore, Glanzmann's thrombasthenia is probably a “Zw-null disease.” The expression of the Zwa antigen on the platelets of all the relatives was normal, as indicated on the cytoflurograph. Investigations on the expression of the Koa antigen were complicated by agglutinations of the platelets from genetically Koa-negative thrombasthenic patients with the anti-Koa serum. The Kob antigen was normally expressed. The Baka antigen was absent from the platelets of all thrombasthenic patients and a relatively high percentage of the relatives. A close association between the Glanzmann gene and the Bak(a-) gene is assumed on statistical grounds. Thrombasthenic platelets showed no reaction with EDTA-dependent antibodies, which are reactive with all normal platelets. Owing to immunization by multiple blood and platelet transfusions, serum samples of most patients studied contained HLA antibodies and platelet-specific alloantibodies. However, antibodies directed against the Zw-antigen-bearing glycoproteins were detected in the serum of only one patient and, therefore, seem to be rare.

Description: Platelet immunofluorescence, together with other serologic tests on platelets, lymphocytes, and granulocytes, was used to investigate the sera of 38 mothers with newborns who suffered from thrombocytopenia. In sera of 33 mothers, platelet-specific IgG alloantibodies were demonstrable. Three sera also contained HLA antibodies, of which two were only detectable in the lymphocyte cytotoxicity test. Two other sera contained granulocyte-specific alloantibodies. In sera of 2 mothers, antibodies were found that reacted with all cell types in all tests. However, after further analysis, it became clear that platelet- specific alloantibodies were probably also present in these 2 sera. In 29 cases, the specificity of the platelet alloantibodies was anti-Zwa-- PlA1. One serum contained antibodies directed against a new antigen, Baka. This new antigen was defined after the investigation of the family and a small-scale population study. Two other sera had platelet antibodies with still undefined specificities. In all positive sera, IgG platelet alloantibodies were detected, and sometimes IgM antibodies were also present. The IgG antibodies were mostly of the IgG1 subclasses, but sometimes IgG3 and/or IgG4 was also found. In a few sera, only IgG3 antibodies were detected. In our series, we found no increased frequency of blood group ABO compatibility between mother and child, although it has been described by others and is well known to occur in rhesus alloimmunization. Of all the tests used, the platelet immunofluorescent test, especially the test on paraformaldehyde-fixed platelets in suspension, gave the best results in the detection of platelet antibodies in neonatal alloimmune thrombocytopenia.

Description: Mononuclear cells (MNCs) containing peripheral blood stem cells (PBSCs) were obtained from solid-tumor patients undergoing mobilizing chemotherapy followed by granulocyte colony-stimulating factor for PBSC transplantation-supported dose-intensified anticancer chemotherapy and were transplanted into unconditioned “nonleaky” young severe combined immunodeficient mice. Multilineage engraftment was shown by flow cytometry and immunocytochemistry using monoclonal antibodies to various human cell surface antigens as well as identification of human immunoglobulin in murine sera. Within a dose range of MNCs suitable for transplantation (10 to 36 x 10(6) cells/graft) the number of CD34+ cells injected (optimal at 〉 0.7 x 10(6)/graft) determined the yield of human cells produced in recipient animals. Engraftment of hu PBSC preparations resulted in prolonged generation of physiologic levels of human cytokines including interleukin-3 (IL-3), IL-6, and granulocyte- macrophage colony-stimulating factor, which were detectable in the murine blood over a period of at least 4 months. In vivo survival of immature human progenitor cells was preserved even 9 months after transplantation. Because human IL-3 is known to stimulate early hematopoiesis, a rat fibroblast cell line was stably transfected with a retroviral vector carrying the human IL-3 gene and cotransplanted subcutaneously as additional source of growth factor. Cotransplants of this cell line producing sustained in vivo levels of circulating human IL-3 for at least 12 weeks significantly accelerated the process of engraftment of huPBSC and spurred the spread of mature human cells to the murine spleen, liver, thymus, and peripheral blood. Cotransplants of allogeneic human bone marrow stromal cells derived from long-term cultures resulted in a comparable--though less prominent--support of engraftment.

Description: The platelets of 11 patients with Glanzmann's thrombasthenia and their nearest family members were studied for the expression of the platelet- specific alloantigens of the Zw-, Ko- and Bak systems. The strength of the expression of the Zwa antigen was diminished on the platelets of 3 patients, and the antigen was absent from the platelets of the other 8. The platelets of none of the patients reacted with anti-Zwb serum. Therefore, Glanzmann's thrombasthenia is probably a “Zw-null disease.” The expression of the Zwa antigen on the platelets of all the relatives was normal, as indicated on the cytoflurograph. Investigations on the expression of the Koa antigen were complicated by agglutinations of the platelets from genetically Koa-negative thrombasthenic patients with the anti-Koa serum. The Kob antigen was normally expressed. The Baka antigen was absent from the platelets of all thrombasthenic patients and a relatively high percentage of the relatives. A close association between the Glanzmann gene and the Bak(a-) gene is assumed on statistical grounds. Thrombasthenic platelets showed no reaction with EDTA-dependent antibodies, which are reactive with all normal platelets. Owing to immunization by multiple blood and platelet transfusions, serum samples of most patients studied contained HLA antibodies and platelet-specific alloantibodies. However, antibodies directed against the Zw-antigen-bearing glycoproteins were detected in the serum of only one patient and, therefore, seem to be rare.