Toxicity and efficacy of autologous hematopoietic cell transplantation in elderly patients with aggressive lymphoma: a historical prospective study.

High-dose therapy followed by autologous hematopoietic cell transplantation (HCT) prolongs overall survival in patients under 65 years old with relapsed aggressive lymphoma. We aimed to explore the toxicity and efficacy of HCT in patients over 65 years with aggressive lymphoma compared with younger patients. We compared the transplantation outcomes between patients ≥ 65 years (n = 58) and 55-64 years (n = 44) with chemosensitive aggressive lymphoma (DLBCL, MCL and TCL) that underwent HCT between 1999 and 2016 in the Tel-Aviv Medical Center. The median age was 68 (range, 65-74) and 61 (range, 55-64) years, respectively. There were no differences in the incidences of grade 3-4 mucositis, documented infections and pulmonary complications between the two groups. There was no difference in the incidences of secondary malignancies, relapse (p = .26), non-relapse mortality, (p = .77) and overall survival (p = .53). Multivariate analysis revealed that smoking was a risk factor for non-relapse mortality, while partial remission and > 2 lines of treatment prior HCT were associated with higher risk for relapse. Psycho-socioeconomic score was associated with prolonged hospitalization after HCT and recurrent hospitalizations. We conclude that patients ≥ 65 years old with aggressive lymphoma, compared to younger counterparts, have similar transplantation outcome. Improving habits and psychosocial factors may further improve outcomes in these patients.

JAK2 mutation: an aid in the diagnosis of occult myeloproliferative neoplasms in patients with major intraabdominal vein thrombosis and normal blood counts.

BACKGROUND: Janus kinase-2 (JAK2) is mutated in a high proportion of patients with polycythemia vera and in a smaller number with essential thrombocythemia and primary myelofibrosis. Mutated JAK2 is an important diagnostic marker for myeloproliferative neoplasm (MPN) and may also play a major role in the pathogenesis of MPN. OBJECTIVES: To evaluate the prevalence of mutated JAK2 (JAK2-V617F) among patients with major intraabdominal vein thrombosis who had normal blood counts at diagnosis of the initial event. METHODS: The medical records of patients who presented with a major intraabdominal venous thrombosis and normal peripheral blood counts were obtained. JAK2-V617F mutation status was determined by real-time polymerase chain reaction. RESULTS: Twenty-two patients were available for this analysis and 9 (41%) were found to have JAK2-V617F. Patients with positive JAK2-V617F were younger and had more frequent clinical splenomegaly than those with wild-type JAK2. CONCLUSIONS: A high proportion of patients presenting with "idiopathic" major intraabdominal vein thrombosis and normal blood counts carry JAK2-V617F. We recommend searching for the mutation in this clinical setting to detect patients with occult MPN.

Tellurium compound provides pro-apoptotic signaling in drug resistant multiple myeloma.

Multiple Myeloma, effectively treated by chemotherapeutic drugs, relapses due to drug resistance. We tested here the capacity of mesenchymal stromal cells, from the bone marrow of patients or from adipose tissue of healthy individuals, to induce drug resistance in Myeloma cell lines. We show that drug resistance can be achieved by factors secreted by the various MSC's. Mass spectrometry analysis of MSC's conditioned media revealed that fibronectin, was particularly instrumental in providing anti-apoptotic signals to MM cells. Moreover, we demonstrate that SAS ([octa-O-bis-(R,R)tartarate ditellurane]), an immunomodulator Tellurium compound, is not only able of blocking the physical interaction between MM cells and fibronectin but is also capable of re-sensitizing the cells to the chemotherapeutic drugs. Finally, we show that this re-sensitization is coupled with the blocking of pAKT induction, in MM cells, by the MSC's. These results indicate that SAS may be useful in the treatment of drug resistant MM.

Treatment of Multiple Myeloma Using Chimeric Antigen Receptor T Cells with Dual Specificity.

Chimeric antigen receptor (CAR) T-cell therapy has shown remarkable successes in fighting B-cell leukemias/lymphomas. Promising response rates are reported in patients treated with B-cell maturation antigen (BCMA) CAR T cells for multiple myeloma. However, responses appear to be nondurable, highlighting the need to expand the repertoire of multiple myeloma-specific targets for immunotherapy and to generate new CAR T cells. Here, we developed a "dual-CAR" targeting two multiple myeloma-associated antigens and explored its safety and efficacy. To reduce the "off-target" toxicity, we used the recognition of paired antigens that were coexpressed by the tumor to induce efficient CAR T-cell activation. The dual-CAR construct presented here was carefully designed to target the multiple myeloma-associated antigens, taking into consideration the distribution of both antigens on normal human tissues. Our results showed that the CD138/CD38-targeted dual CAR (dCAR138-38) elicited a potent anti-multiple myeloma response both in vitro and in vivo NSG mice transplanted with a multiple myeloma cell line and treated with dCAR138-38 showed median survival of 97 days compared with 31 days in the control group treated with mock-lymphocytes. The dCAR138-38 showed increased specificity toward cells expressing both targeted antigens compared with single-antigen-expressing cells and low activity toward primary cells from healthy tissues. Our findings indicated that the dCAR138-38 may provide a potent and safe alternative therapy for patients with multiple myeloma.

Impaired lymphocyte reconstitution after autologous transplant is associated with apoptosis of CD8+ T cells and adverse clinical outcome.

We noticed that the lymphocyte counts, after autologous hematopoietic stem cell transplantation, oscillated during the first 4 post-transplant months. Thereafter, the lymphocyte counts stabilized and segregated the patients into two groups, those who normalized their lymphocyte counts and those with prolonged lymphopenia. In both groups, the CD4 counts remained low for at least 6 months. However, in approximately half of the patient, the CD8 counts increased to normal or above normal values. Patients with prolonged lymphopenia had higher rates of lymphocytes' spontaneous apoptosis and the lymphocytes in patients who restored their counts expressed the intracellular CD14-derived MO2 epitope that protects the cells from apoptosis. These findings were translated to longer disease-free survival and overall survival in patients who restored the CD8 counts. Collectively, our data show that post-transplant lymphocytes that express intracellular CD14-MO2 epitope have survival advantage.

CXCR4 regulates migration and development of human acute myelogenous leukemia stem cells in transplanted NOD/SCID mice.

The chemokine stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 participate in the retention of normal hematopoietic stem cells within the bone marrow (BM) and their release into the circulation. Homing and engraftment of human stem cells in immunodeficient mice are dependent on cell surface CXCR4 expression and the production of BM SDF-1, which acts also as a survival factor for both human and murine stem cells. However, the role of SDF-1/CXCR4 interactions in the control of human acute myelogenous leukemia (AML) cell trafficking and disease progression is poorly understood. In this study, we report that although some AML cells do not express surface CXCR4, all AML cells tested express internal CXCR4 and SDF-1. Culture of AML cells with SDF-1 promoted their survival, whereas addition of neutralizing CXCR4 antibodies, SDF-1 antibodies, or AMD3100 significantly decreased it. Pretreatment of primary human AML cells with neutralizing CXCR4 antibodies blocked their homing into the BM and spleen of transplanted NOD/SCID/B2m(null) mice. Furthermore, weekly administrations of antihuman CXCR4 to mice previously engrafted with primary AML cells led to a dramatic decrease in the levels of human AML cells in the BM, blood, and spleen in a dose- and time-dependent manner. Interestingly, the same treatment did not affect significantly the levels of normal human progenitors engrafted into NOD/SCID mice. Taken together, our findings demonstrated the importance of the SDF-1/CXCR4 axis in the regulation of in vivo motility and development of human AML stem cells and identified CXCR4 neutralization as a potential treatment for AML.

Autoimmune thrombocytopenia in chronic myeloid leukemia treated with interferon-alpha: differential diagnosis and possible pathogenesis.

Interferon-alpha (INF-alpha) is an effective anti-neoplastic and anti-viral drug. Treatment with INF-alpha is frequently complicated by adverse effects, which may rarely be immune mediated. We report 2 patients with Ph+ chronic myeloid leukemia (CML) who developed autoimmune thrombocytopenia while receiving months of treatment with INF-alpha. This complication responded well to discontinuation of interferon and administration of steroids treatment. Here, we also summarize the literature on INF-alpha induced autoimmune thrombocytopenia, and discuss differential diagnosis and possible mechanisms involved in the development of thrombocytopenia during therapy with INF-alpha.

Enoxaparin can be used safely in patients with severe thrombocytopenia due to intensive chemotherapy regimens.

Treatment with intensive chemotherapy regimens is frequently complicated by severe thrombocytopenia. During the period of severe thrombocytopenia, anticoagulant treatment is not uncommonly indicated for thromboembolic events or thromboprophylaxis in these patients. We report 10 hematological patients treated with intensive chemotherapy protocols that were anticoagulated with enoxaparin for catheter related central venous thrombosis and thromboprophylaxis. During the period of severe thrombocytopenia the dosages of enoxaparin were reduced and no major bleeding occurred. Based on our experience we suggest that reduced dosages of low molecular weight heparins may be used relatively safely during transient severe thrombocytopenia.

Leukomogenic factors downregulate heparanase expression in acute myeloid leukemia cells.

Heparanase is a heparan sulfate-degrading endoglycosidase expressed by mature monocytes and myeloid cells, but not by immature hematopoietic progenitors. Heparanase gene expression is upregulated during differentiation of immature myeloid cells. PML-RARalpha and PLZF-RARalpha fusion gene products associated with acute promyelocytic leukemia abrogate myeloid differentiation and heparanase expression. AML-Eto, a translocation product associated with AML FAB M2, also downregulates heparanase gene expression. The common mechanism that underlines the activity of these three fusion gene products involves the recruitment of histone deacetylase complexes to specific locations within the DNA. We found that retinoic acid that dissociates PML-RARalpha from the DNA, and which is used to treat acute promyelocytic leukemia patients, restores heparanase expression to normal levels in an acute promyelocytic leukemia cell line. The retinoic acid effects were also observed in primary acute promyelocytic leukemia cells and in a retinoic acid-treated acute promyelocytic leukemia patient. Histone deacetylase inhibitor reverses the downregulation of heparanase expression induced by the AML-Eto fusion gene product in M2 type AML. In summary, we have characterized a link between leukomogenic factors and the downregulation of heparanase in myeloid leukemic cells.

Immunotherapy of murine leukemia following non-myeloablative conditioning with naïve or G-CSF mobilized blood or bone marrow stem cells.

Allogeneic stem cell transplantation (SCT) is the treatment of choice for a large number of hematologic malignancies. Its major advantage over conventional chemotherapy lies in the graft-versus-leukemia (GVL) effects mediated by allo- or tumor-reactive donor lymphocytes given in the course of SCT or post transplantation as donor lymphocyte infusions (DLI). The benefits of cell-mediated immunotherapy over myeloablative radiochemotherapy have also made it possible to reduce the intensity of conditioning regimens. Mobilized peripheral blood has proved preferable to bone marrow (BM) as a source of stem cells for transplantation, since it provides a larger number of stem cells on the one hand and immunologically competent lymphocytes on the other. The use of granulocyte colony stimulating factor (G-CSF), which is necessary to mobilize and increase the number of stem cells, may down-regulate the GVL effect by suppression of donor effector T lymphocytes by inducing Th1-->Th2 cytokine switch. It has previously been shown that GVL effects may be amplified by both in vivo and in vitro activation of donor lymphocytes with human recombinant interleukin-2 (rIL-2). Our studies using a leukemic murine model prepared for transplantation with low intensity conditioning prior to infusion of G-CSF-mobilized peripheral blood stem cells (PBSC) have demonstrated that mobilization of blood cells with G-CSF and in vivo treatment with rIL-2 following low-intensity conditioning enhances the GVL effects and prolongs survival of recipients inoculated with BCL1. Activation of donor lymphocytes with rIL-2 may thus be useful for amplifying GVL effects following mobilization with G-CSF.