Elimination of neoplastic cells from peripheral blood progenitor cells (PBPCs) is an important issue in transplantation-based high-dose chemotherapy in non Hodgkin’s lymphoma (NHL). The capacity to reliably assess the presence of residual lymphoma cells in PBPCs is mandatory in designing this type of protocols. Polymerase chain reaction (PCR) amplification of molecular rearrangements is widely used to detect minimal residual disease (MRD) in NHL patients. Although concordant data can be obtained in most of the cases from peripheral blood (PB) and bone marrow (BM) at diagnosis, the relationship between these two compartments and the role of their analysis in predicting the molecular status of PBPCs is still an open issue. Here we report data about MRD analysis in BM, PB and PBPCs in a series of mantle cell and indolent NHL patients who underwent high-dose chemotherapy: discordant results were obtained comparing PB, BM and PBPC molecular data. In addition, differences were noted among these results if molecular analysis was performed using well-known rearrangements (i.e., bcl-1/IgH and bcl-2/IgH) or patient specific oligonucleotides. We conclude that neither BM nor PB are reliable in predicting the molecular status of PBPCs and that caution must be adopted in interpreting molecular data obtained using patient specific oligonucleotides.

Immunotherapy is theoretically an attractive therapeutic option for patients with hematological malignancies. Various laboratory studies suggested the importance of the choice of tumor antigen for successful immunotherapy. Cancer-testis antigens (CTAs) are potentially suitable molecules for tumor vaccines of hematological malignancies because of their high immunogenicity in vivo, even in cancer-bearing patients, and their relatively restricted normal tissue distribution. Tumor cell kill using a CTA-based immunotherapy will, therefore, be more specific and associated with less toxicities when compared to chemotherapy. Many CTAs have been identified in various hematologic malignancies. In this review, we will take the readers through the journey of hopes and the disappointments arisen from the discovery of CTAs. We will describe the features of CTAs and their expression in hematologic malignancies. We will also discuss the mechanisms regulating the expression of these CTAs, from a primary regulatory mechanism involving DNA methylation to secondary controls by cytokines. Finally, we will address the potential obstacles that will prevent the successful use of CTAs as targets for tumor immunotherapy.

High mobility group box 1 (HMGB1) is a nuclear DNA-binding protein, which functions as Damage Associated Molecular Pattern molecule (DAMP) when released from cells under conditions of stress, such as injury and infection. Recent studies indicate that HMGB1 plays an important role in leukemia pathogenesis and chemotherapy resistance. Serum HMGB1 is increased in childhood acute lymphocytic leukemia as compared to healthy control and complete remission groups. Moreover, HMGB1 is a negative regulator of apoptosis in leukemia cells through regulation of Bcl-2 expression and caspase-3 activity. As a positive regulator of autophagy, intracellular HMGB1 interacts with Beclin 1 in leukemia cells leading to autophagosome formation. Additionally, exogenous HMGB1 directly induces autophagy and cell survival in leukemia cells. Experimental strategies that selectively target HMGB1 effectively reverse and prevent chemotherapy resistance in leukemia cells, suggesting that HMGB1 is a novel therapeutic target in leukemia.

Bim, a BH3-only Bcl-2-family protein, is essential for T-cell negative selection in the thymus as well as for the death of activated T cells in the periphery. The role of Bim has been extensively studied in T-cell responses to self-antigens and viral infections. Recent findings on Bim in autoimmunity triggered our interest in investigating whether Bim may play a role in another disease with inflammatory symptoms as graft-versus-host disease (GVHD). Here we report that Bim is required for optimal T-cell responses to alloantigens in vivo and for the development of GVHD. Using murine models of allogeneic bone marrow transplantation (BMT), we found that donor T cells deficient for Bim are impaired in the induction of GVHD primarily due to a significant defect in T cell activation and expansion in vivo. Upon TCR engagement, Bim-/- T cells exhibited selective defects in CD69 expression and phosphorylation of PLCγ1. Our studies uncover a novel aspect of Bim function in T-cell activation with important implications in understanding the mechanisms of T-cell activation and tolerance under allogeneic transplantation.

AL amyloidosis is the most common form of systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. The disease is often difficult to recognize because of its broad range of manifestations and, what are often, vague symptoms. Recent diagnostic and prognostic advances include the serum free light chain assay, cardiac magnetic resonance imaging, and serologic cardiac biomarkers. Treatment strategies that have evolved during the past decade are prolonging survival and preserving organ function in patients with this disease. This review outlines the role of high dose melphalan and stem cell transplantation in the treatment of AL amyloidosis.

The Vav family of proteins are guanine nucleotide exchange factors which have been shown to be deregulated in several types of human cancer. There are three members of the Vav family that have been identified which are members of the Dbl domain superfamily and have specificity towards Rho/Rac GTPases. The Vav family plays an important role in normal hematologic system development and homeostasis, and Vav1 is largely restricted to the hematologic system. While Vav1 was originally identified as a proto-oncogene, several recent studies have shown that Vav family deletion leads to the development of T-cell malignancies in mice. In addition, Vav1 has been shown to play a role in the ATRA-mediated differentiation of promyelocytic leukemia cells. In this concise review, the gene structure and normal function of Vav1, as well as a possible role for Vav1 in the development of hematologic and other malignancies is reviewed.

In recent years, the prospective isolation of hematopoietic stem and progenitor cells has identified the hierarchical structure of hematopoietic development and lineage-commitment. Moreover, these isolated cell populations allowed the elucitation of the molecular mechansims associated with lineage choice and revealed the indispensable functions of transcription factors as lineage determinants. This review summarizes current concepts regarding adult murine granulopoiesis and illustrates the importance of the transcription factors C/EBPα, PU.1 and GATA-2 for the development of neutrophil, eosinophil and basophil granulocytes.

Epidemiological studies performed over the last decade have demonstrated a positive association between persistent, hepatitis B surface antigen (HBsAg)-positive hepatitis B virus (HBV) infection and B-cell non-Hodgkin lymphoma (NHL), with HBV-infected patients having a 2-3-fold higher risk to develop NHL than non-infected patients. Moreover, there is evidence that also occult HBV infection (HBsAg-negative, HBV DNA-positive) associates with NHL. An association with HBV infection may exist also for other hematological malignancies, but available evidence is much less persuasive than for NHL. In this review article we will discuss available results on the association between HBsAg-positive HBV infection and NHL, as well as the significance of other serological markers of HBV infection in these subjects. We will also discuss the possible etiopathogenic role of HBV, and propose a multifactorial model for lymphomagenesis. Experimental evidence for multifactorial etiopathogenesis has been obtained in recent years for HBV-associated hepatocellular carcinoma (HCC), and we suggest that a similar model may apply to HBV-associated lymphoma as well. Eventually, we will also address some unresolved questions. Two of these are of particular relevance. First, do HBV-positive NHL patients show regression of their hematologic malignancy upon antiviral therapy? A positive answer would represent a direct demonstration of the necessary etiological role of the virus in the development of NHL, as has been shown previously for HCV-associated lymphomas. Second, if HBV plays a necessary role in lymphomagenesis, then expansion of HBV vaccination is expected to reduce the number of incident NHL cases, even though this effect might become evident only after a long time interval. Studies in those countries which have introduced universal HBV vaccination about two decades ago, like Italy, may soon provide results on this important point.

Hematopoietic stem cells (HSCs) that give rise to all blood cell types are important vehicles for cell-based and gene therapies. After isolation from the bone marrow, HSCs are often cultured in laboratory settings for purposes of ex vivo expansion, gene transduction, and bone marrow transplantation for the treatment of various disorders of the blood and immune systems. Here we demonstrate that during in vitro culturing outside of hypoxic bone marrow niches, HSCs may genetically alter even after short durations of time. Lineage- Scal-1+ c-Kit+ (LSK) cells that are enriched with HSCs revealed significant levels of genomic instability following culture, as evidenced by the emergence of aneuploid cells. To further determine the effects of in vitro culturing conditions, whole bone marrow cells were cultured in a hypoxic environment of 3% oxygen, mimicking conditions within the body's bone marrow, following which, cells proved to undergo less genetic alterations. Proper dosages of the antioxidant N-Acetyl-Cysteine (NAC) similarly decreased occurrences of chromosomal change. Furthermore, analysis of aged hematopoietic cells revealed enhanced in vitro normoxic culture-induced chromosomal instability compared to that of young hematopoietic cells due to noted increased oxidative stress in aged cells. These results reveal that in vitro cell culturing does indeed cause genomic instability in hematopoietic cells. Reduced oxygen to physiological levels and additions of antioxidants can be employed as possible strategies to lower oxidative stress and decrease chances of chromosomal transformation. Because hematopoietic cells are commonly processed in laboratory settings before transplantation for patient treatment, our findings also raise a concern on the therapeutic use of cultured hematopoietic cells.

Platelet-derived growth factors (PDGF) bind to two closely related receptor tyrosine kinases, PDGF receptor α and β, which are encoded by the PDGFRA and PDGFRB genes. Aberrant activation of PDGF receptors occurs in myeloid malignancies associated with hypereosinophilia, due to chromosomal alterations that produce fusion genes, such as ETV6-PDGFRB or FIP1L1-PDGFRA. Most patients are males and respond to low dose imatinib, which is particularly effective against PDGF receptor kinase activity. Recently, activating point mutations in PDGFRA were also described in hypereosinophilia. In addition, autocrine loops have been identified in large granular lymphocyte leukemia and HTLV-transformed lymphocytes, suggesting new possible indications for tyrosine kinase inhibitor therapy. Although PDGF was initially purified from platelets more than 30 years ago, its physiological role in the hematopoietic system remains unclear. Hematopoietic defects in PDGF-deficient mice have been reported but appear to be secondary to cardiovascular and placental abnormalities. Nevertheless, PDGF acts directly on several hematopoietic cell types in vitro, such as megakaryocytes, platelets, activated macrophages and, possibly, certain lymphocyte subsets and eosinophils. The relevance of these observations for normal human hematopoiesis remains to be established.

This report discusses the case of a 52 year old female with post-transplant lymphoproliferative disorder, confined to the central nervous system, which was managed with high dose methotrexate (HDMTX) in the context of end stage renal disease. The patient received two doses of HDMTX followed by extended hours high-flux hemodialysis, plasma methotrexate concentration monitoring and leucovorin rescue. The hemodialysis technique used was effective in clearing plasma methotrexate and allowed delivery of HDMTX to achieve complete remission with limited and reversible direct methotrexate-related toxicity. Dialysis-dependent renal failure does not preclude the use of HDMTX when required for curative therapy of malignancy.

Grb2-associated binding (Gab) scaffolding/adapter proteins are a family of three members including mammalian Gab1, Gab2, and Gab3 that are highly conserved. Since the discovery of these proteins, there has been an extensive amount of work done to better understand Gab functional roles in multiple signaling pathways, typically acting as a downstream effectors of receptor-tyrosine kinase (RTK)-triggered signal transduction. In addition to their participation in hematopoiesis, Gabs play important roles in regulation of immune response and in also in cancer cell signaling. Gabs may play complex roles and thus a complete understanding of their interactions and how they modulate hematopoietic and immune cell biology remains to be determined. This review will cover the most recent findings including the involvement of Gabs in disease development and signaling which will be important for design of future therapeutic interventions.

Multiple myeloma (MM) still remains incurable in most of the patients. Despite of treatments with high-dose chemotherapy, stem cell transplantation and other novel therapies, most patients will become refractory to the therapies and relapse. Thus, it is urgent to develop new approaches for MM treatment. Currently, antibody-targeted therapy has been extensively utilized in hematological malignancies, including MM. Several novel monoclonal antibodies (mAbs) against MM have been generated and developed over the past several years. These mAbs aim to target not only tumor cells alone but also tumor microenvironment, including interaction of tumor-bone marrow stromal cells and the components of bone marrow milieu, such as cytokines or chemokines that support myeloma cell growth and survival. These include mAbs specific for CD38, CS1, CD40, CD74, CD70, HM1.24, interleukin-6 and β2-microglobulin (β2M). We have shown that anti-β2M mAbs may be a potential antitumor agent for MM therapy due to their remarkable efficacy to induce myeloma cell apoptosis in tumor cell lines and primary myeloma cells from patients in vitro and in established myeloma mouse models. In this article, we will review advances in the development and mechanisms of MM-targeted mAbs and especially, anti-β2M mAbs. We will also discuss the potential application of the mAbs as therapeutic agents to treat MM.

C-MOPP is a chemotherapy regimen for the treatment of Non-Hodgkin lymphoma (NHL). Because rituximab improves results in B-cell NHL, we added rituximab to C-MOPP, giving it the term C-MOPP-R. We retrospectively report the results of C-MOPP-R treatment for follicular lymphoma at Saint Louis University Cancer Center from 2000-2009. Treatment response was assessed with fusion PET/CT using International Harmonization Project Criteria and toxicity using National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0. Thirty-seven patients with follicular lymphoma were treated at our institution with C-MOPP-R. The complete response rate was ninety-four percent and sixty-eight percent in untreated and relapsed patients, respectively. The median progression-free and overall survivals were not reached with median observation time of 34 months. Development of peripheral neuropathy required truncation of planned vincristine dosing in nearly half of patients. We believe that C-MOPP-R results in excellent response rates, progression-free, and overall survival for untreated and relapsed follicular lymphoma and capped vincristine dosing is essential to optimize safety.

The treatment of multiple myeloma has undergone important changes in the last few years. The use of novel agents, such as the immunomodulatory drugs thalidomide and lenalidomide, and the proteasome inhibitor bortezomib, has increased the treatment options available and significantly improved the outcome of this rare disease. Several trials have shown the advantages linked to the use of novel agents both in young patients, who are considered eligible for transplantation, and elderly patients, who are considered transplant ineligible. In the non-transplant setting, novel agent-containing regimens have replaced the traditional melphalan-prednisone approach. Preliminary data also support the role of consolidation and maintenance therapy to further improve outcomes. An appropriate management of side effects is fundamental for the success of the treatment, and outcome should always be balanced against the toxicity profile associated with the regimen used. This review provides an overview of the latest strategies including novel agents used to treat elderly patients with multiple myeloma.

Diagnosis of B-non Hodgkin lymphomas (NHLs) is based on clinical, morphological and immunohistochemi-cal features. However, in up to 10-15% of cases, analysis of immunoglobulin heavy (IGH) or light (IGK/IGL) chains genes is required to discriminate between malignant and reactive lymphoid proliferations. In this study, we evaluated the feasibility and efficiency of IGK analysis in the routine diagnostic of B-cell lymphoproliferative disorders (B-LD) when applied to formalin-fixed paraffin-embedded (FFPE) tissues. Clonality patterns were studied in 59 B-LD using the BIOMED-2 protocol for IGK assays, after failure of the IGH assay. PCR products were evaluated by both heterodu-plex and GeneScan analysis. IGK analysis was technically successful in all cases. Overall, it supported the histopa-thological suspicion in 52/59 cases (88%), the sensitivity and specificity being 83% and 80%, respectively. Further, positive and negative predictive values were 95% and 50%, respectively. Interestingly, among various lymphoma subtypes, marginal zone lymphoma and follicular lymphoma most frequently required IGK analysis. In conclusion, IGK study according to the BIOMED-2 protocol resulted feasible and extremely useful in supporting challenging diagnosis of B-LD even if applied on FFPE samples. Accordingly, when NHL is suspected, negative results at IGH analysis should not be considered as conclusive and further investigation of IGK is appropriate.

Background: Anemia is an important cause of morbidity in MDS patients, principally through increased cardiovascular disease. Transfusion status has been seen to be a significant prognostic factor for disease progression and mortality, yet the relationship between anemia levels and cardiovascular disease is not well understood. Objective: This study aimed to review the published literature on the effect of anemia on cardiovascular outcomes in patients with MDS. Methods: A systematic literature review was undertaken to identify studies that investigated the relationship between anemia (as defined by hemoglobin levels) and cardiovascular outcomes in patients with MDS (all subtypes). Results: Three studies were identified that explicitly evaluated the relationship between anemia and cardiovascular outcomes in MDS, and another study reported the relationship between hemoglobin levels and survival. The four studies consistently showed a strong relationship between lower hemoglobin levels and worse cardiovascular outcomes, including cardiac remodeling, congestive heart failure, coronary artery disease, myocardial infarction, arrhythmia, heart valve disease, and cardiovascular mortality. Anemia was seen to be an independent predictor of cardiovascular disease outcomes in patients with MDS, beyond transfusion status and IPSS. Conclusion: Based upon a relatively small body of evidence, there appears to be a strong and clinically significant association between anemia and cardiovascular morbidity and mortality in MDS. While further research is needed, clinicians should seek to actively manage hemoglobin levels in MDS patients before the point of transfusion dependency is reached.

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy which is cured in a minority of patients. A FLT3-internal tandem duplication (ITD) mutation, found in approximately a quarter of patients with de novo AML, imparts a particularly poor prognosis. Patients with FLT3-ITD AML often present with more aggressive disease and have a significantly higher propensity for relapse after remission. The therapeutic approach for these patients has traditionally included intensive induction chemotherapy, followed by consolidative chemotherapy or hematopoietic cell transplantation (HCT). In recent years, multiple small molecule inhibitors of the FLT3 tyrosine kinase have been studied preclinically and in clinical trials. The earlier generation of these agents, often non-specific and impacting a variety of tyrosine kinases, produced at best transient peripheral blood responses in early clinical trials. Additionally, the combination of FLT3 inhibitors with cytotoxic regimens has not, as of yet, demonstrated an improvement in overall survival. Nevertheless, multiple current trials, including those with sorafenib, lestaurtinib, and midostaurin, continue to study the combination of FLT3 inhibitors with standard chemotherapy. Factors such as sustained FLT3 inhibition, protein binding, pharmacokinetics, and the presence of elevated FLT3-ligand levels appear to significantly impact the potency of these agents in vivo. In recent years, the development of more specific and potent agents has generated hope that FLT3 inhibitors may play a more prominent role in the treatment of FLT3-ITD AML in the near future. Nevertheless, questions remain regarding the optimal timing and schedule for incorporation of FLT3 inhibitors. The suitability, type, and timing of allogeneic HCT in the therapeutic approach for these patients are also issues which require further study and definition. Recent retrospective data appears to support the efficacy of allogeneic HCT in first complete remission, possibly due to a graft versus leukemia effect. However, larger prospective studies are necessary to further elucidate the role of HCT and its potential combination with FLT3 inhibitor therapy. We are hopeful that current clinical investigation will lead to an optimization and improvement of outcomes for these patients.

Post-transplantation lymphoproliferative disorders (PTLD) arise in the immunosuppressed and are frequently Epstein-Barr virus (EBV) associated. The most common PTLD histological sub-type is diffuse large B-cell lymphoma (EBV+DLBCL-PTLD). Restoration of EBV-specific T-cell immunity can induce EBV+DLBCL-PTLD regression. The most frequent B-cell lymphoma in the immunocompetent is also DLBCL. ‘EBV-positive DLBCL of the elderly’ (EBV+DLBCL) is a rare but well-recognized DLBCL entity that occurs in the overtly immunocompetent, that has an adverse outcome relative to EBV-negative DLBCL. Unlike PTLD (which is classified as viral latency III), literature suggests EBV+DLBCL is typically latency II, i.e. expression is limited to the immuno-subdominant EBNA1, LMP1 and LMP2 EBV-proteins. If correct, this would be a major impediment for T-cell immunotherapeutic strategies. Unexpectedly we observed EBV+DLBCL-PTLD and EBV+DLBCL both shared features consistent with type III EBV-latency, including expression of the immuno-dominant EBNA3A protein. Extensive analysis showed frequent polymorphisms in EB-NA1 and LMP1 functionally defined CD8+ T-cell epitope encoding regions, whereas EBNA3A polymorphisms were very rare making this an attractive immunotherapy target. As with EBV+DLBCL-PTLD, the antigen presenting machinery within lymphomatous nodes was intact. EBV+DLBCL express EBNA3A suggesting it is amenable to immunotherapeutic strategies.

Multiple myeloma (MM) is the second most common hematologic malignancy in the United States and affects about 4 in 100,000 Americans. Even though much progress has been made in MM therapy, MM remains an incurable disease for the vast majority of patients. The existence of MM stem cell is considered one of the major causes of MM drug-resistance, leading to relapse. This highlights the importance and urgency of developing approaches to target MM stem cells. However, very little is known about the molecular characteristics of the MM stem cells, which makes it difficult to target MM stem cells therapeutically. Evidence of the existence of a myeloma stem cell has been provided by Matsui et al. showing that the CD138- and CD20+ fraction, which is a minor population of the MM cells, has a greater clonogenic potential and has the phenotype of a memory B-cell (CD19+, CD27+). In this review, we report recent progress of cell surface markers in cancer stem cells, especially in myeloma and the molecular mechanisms related to drug resistance and myeloma disease progression.

Carbohydrates are traditionally considered to be an important source of energy for living organisms. In the field of biology, they are defined as organic compounds composed of carbon, hydrogen, and oxygen that are organized into ring structures. The analysis of these structures and their functions has led to a new field of biology called “glycobiology.” In the biomedical sciences, glycobiology is rapidly emerging to be an integral part of complex biological processes. Changes in glycan structures and the interactions of these structures with endogenous carbohydrate-binding proteins, known as lectins, are now considered to be potential biomarkers on cancer cells for monitoring tumor progression. Evidence suggesting that the interactions between lectins and their ligands have a major role in the different steps of cancer progression has accumulated at a rapid pace and has gained the attention of several oncologists. This is particularly true for galectin family members because changes in their expression levels correlate with alterations in cancer cell growth, apoptosis, and cell-cell and cell-matrix interactions. Here we provide an integrated view of the role of galectins in hematological malignancies.

Background: Donor Lymphocyte Infusion (DLI) is a well-recognized tool for augmentation of the anti-leukemia effect after mismatched bone marrow transplantation. Experimental results show, however, that DLI efficacy is strongly dependent on the number of donor hematopoietic cells persisting in recipient after transplantation. It is strong in mixed chimeras and relatively weak in full chimeras (FC) that replace host antigen-presenting cells by donor antigen-presenting cells. In this study we applied a new in vivo cytotoxicity monitoring method for evaluation of the changes in FC anti-host immunity after co-transplantation of donor and host hematopoietic cells together. Method: Full hematopoietic chimeras and naïve control mice were transplanted with a mixture of equivalent numbers of donor and recipient or donor and third party splenocytes labeled by a cell-permeable fluorescent dye CFDA-SE. The animals were sacrificed at various time points, and their splenocyte suspensions were prepared, depleted of red blood cells, stained with allophycocyanin-labeled anti-H2b antibodies, and analyzed using fluorescence-activated cell sorting. The immune response was assessed according to the percentage of single positive CFDA-SE+/ H2b- cells of all CFDA-SE+ cells. Results: FC grafted with splenocytes from similar FC mixed with splenocytes from naïve host-type or third-party-type mice rejected host cells within 14 days, and third-party cells within 7 days. NK cell depletion in vivo had no influence on host cell rejection kinetics. Co-infusion of host-type splenocytes with splenocytes obtained from naïve donor-type mice resulted in significant acceleration of host cell rejection (10 days). Naïve mice rejected the same amount of allogeneic lymphocytes within 3 days. Conclusions: Proposed method provides a simple and sensitive tool to evaluate in vivo post-transplant cytotoxicity in different experimental settings. The method demonstrates that FC is specifically deficient in their ability to reject host lymphocytes even when antigen-presenting host cells are provided. DLI improve anti-host immune response in FC but can not restore it to the level observed in naïve donor-type mice.

Grb2-associated binding (Gab) scaffolding/adapter proteins are a family of three members including mammalian Gab1, Gab2, and Gab3 that are highly conserved. Since the discovery of these proteins, there has been an extensive amount of work done to better understand Gab functional roles in multiple signaling pathways, typically acting as a downstream effectors of receptor-tyrosine kinase (RTK)-triggered signal transduction. In addition to their participation in hematopoiesis, Gabs play important roles in regulation of immune response and in also in cancer cell signaling. Gabs may play complex roles and thus a complete understanding of their interactions and how they modulate hematopoietic and immune cell biology remains to be determined. This review will cover the most recent findings including the involvement of Gabs in disease development and signaling which will be important for design of future therapeutic interventions.