Purging in BCR-ABL-positive acute lymphoblastic leukemia using immunomagnetic beads: comparison of residual leukemia and purging efficiency in bone marrow vs peripheral blood stem cells by semiquantitative polymerase chain reaction

Separation mixed semen of two individuals using magnetic beads coupled ABH blood group antibody

In sexual assault cases, one of the most common samples collected is a mixed semen stain, which is often found on the vagina, female underwear, or bed sheets. However, it is usually difficult to identify the perpetrator based on this sample alone. One technique that has been developed to address this issue is magnetic bead-based separation. This method involves using modified magnetic microspheres to capture and enrich specific target cells, in this case, sperm cells. In this study, we utilized magnetic beads coupled with ABH blood group antibody to isolate sperm cells from an individual of a single ABO blood type. Subsequently, polymerase chain reaction amplification and capillary electrophoresis were employed to perform the genotyping the short tandem repeat (STR) loci. This approach allows for the identification of different individuals in a mixed seminal stain sample from two individuals, by first separating sperm cells based on ABH antigen differences and subsequently utilizing autosomal STR typing on the enriched single blood group cells.

Capturing B type acute lymphoblastic leukemia cells using two types of antibodies

One way to monitor minimal residual disease (MRD) is to screen cells for multiple surface markers using flow cytometry. In order to develop an alternative microfluidic based method, isolation of B type acute lymphoblastic cells using two types of antibodies should be investigated. The immunomagnetic beads coated with various antibodies are used to capture the B type acute lymphoblastic cells. Single beads, two types of beads and surface immobilized antibody were used to measure the capture efficiency. Both micro and nanosize immunomagnetic beads can be used to capture B type acute lymphoblastic cells with a minimum efficiency of 94% and maximum efficiency of 98%. Development of a microfluidic based biochip incorporating immunomagnetic beads and surface immobilized antibodies for monitoring MRD can be an alternative to current cost and time inefficient laboratory methods. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2737, 2019.

Differentiation of normal and leukemic cells by 2D light scattering label-free static cytometry

Two-dimensional (2D) light scattering patterns of single microspheres, normal granulocytes and leukemic cells are obtained by label-free static cytometry. Statistical results of experimental 2D light scattering patterns obtained from standard microspheres with a mean diameter of 4.19 μm agree well with theoretical simulations. High accuracy rates (greater than 92%) for label-free differentiation of normal granulocytes and leukemic cells, both the acute and chronic leukemic cells, are achieved by analyzing the 2D light scattering patterns. Our label-free static cytometry is promising for leukemia screening in clinics.

Oncolytic virotherapy for hematological malignancies

Hematological malignancies such as leukemias, lymphomas, multiple myeloma (MM), and the myelodysplastic syndromes (MDSs) primarily affect adults and are difficult to treat. For high-risk disease, hematopoietic stem cell transplant (HCT) can be used. However, in the setting of autologous HCT, relapse due to contamination of the autograft with cancer cells remains a major challenge. Ex vivo manipulations of the autograft to purge cancer cells using chemotherapies and toxins have been attempted. Because these past strategies lack specificity for malignant cells and often impair the normal hematopoietic stem and progenitor cells, prior efforts to ex vivo purge autografts have resulted in prolonged cytopenias and graft failure. The ideal ex vivo purging agent would selectively target the contaminating cancer cells while spare normal stem and progenitor cells and would be applied quickly without toxicities to the recipient. One agent which meets these criteria is oncolytic viruses. This paper details experimental progress with reovirus, myxoma virus, measles virus, vesicular stomatitis virus, coxsackievirus, and vaccinia virus as well as requirements for translation of these results to the clinic.

Recent advances in the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia

The advent of imatinib, a selective inhibitor of the ABL tyrosine kinase, has revolutionized the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Combined with chemotherapy, imatinib exerts remarkable efficacy in patients with newly diagnosed disease with a complete remission (CR) rate of 95% and a survival rate of 55% at 3 years. Profound eradication of leukemia cells not only provides patients with a better chance for receiving allogeneic hematopoietic stem cell transplantation during first CR but also contributes to durable CR even without transplantation. Despite such improvement, however, relapse does occur, mainly owing to acquisition of resistance. Growing comprehension of the molecular mechanisms of resistance to imatinib has led to the development of novel BCR-ABL inhibitors that yield higher affinity for BCR-ABL and/or potent inhibitory activity against other target molecules such as SRC family kinases. The second-generation ABL kinase inhibitors, namely dasatinib and nilotinib, are already showing clinical activity in patients with imatinib-resistant Ph+ ALL, and other novel agents are undergoing preclinical and early clinical evaluation. Further improvement in treatment results will be achieved by identifying each patient's disease profile based on information obtained before and during treatment and by optimizing subsequent treatment accordingly.

Viral purging of haematological autografts: should we sneeze on the graft?

High-dose cytotoxic chemotherapy followed by autologous haematopoietic stem cell transplantation (ASCT) is extensively used for the treatment of many haematopoietic, as well as several epithelial cancers. Disease relapse may be the result of tumour contamination within autograft as evidenced by gene marking studies. The multiple purging strategies that have been described to date have not proven effective in most ASCT settings. This review addresses the possibility of using oncolytic viruses as a novel purging strategy. DNA viruses such as genetically engineered adenoviral vectors have widely been used to deliver either a prodrug-activating enzyme or express wild-type p53 selectively in tumour cells in ex vivo purging protocols. In addition, conditionally replicating adenoviruses that selectively replicate in tumour cells and herpes simplex virus type 1 are other DNA viruses that have been tested as ex vivo purging agents under laboratory conditions. Vesicular stomatitis virus (VSV) and reovirus are naturally occurring RNA viruses that appear to hold promise as purging agents under ex vivo and in vivo settings. Preclinical data demonstrate reovirus's purging potential against breast, monocytic and myeloma cell lines as well as patient-derived tumours of diffuse large B-cell lymphoma, chronic lymphocytic leukaemia, Waldenstrom macroglobulinemia and small lymphocytic lymphoma. In addition, VSV has shown effective killing of leukaemic cell lines and multiple myeloma patient specimens. Given the increasing interest in the utilization of viruses as purging agents, the following review provides a timely summary of the potential and the challenges of oncolytic viruses as purging modalities during ASCT.

Imatinib combined chemotherapy for Philadelphia chromosome-positive acute lymphoblastic leukemia: major challenges in current practice

The prognosis of Philadelphia chromosome-positive (Ph+) and/or BCR-ABL-positive acute lymphoblastic leukemia (ALL) is extremely poor, and for decades allogeneic hematopoietic stem cell transplantation (HSCT) has been considered the only option for a cure. However, the treatment for Ph+ ALL has been rapidly changing since imatinib, a selective inhibitor of the ABL tyrosine kinase, was introduced. Earlier clinical trials in which a moderate anti-leukemic effect of imatinib monotherapy was demonstrated have prompted investigators to explore the combination of imatinib and chemotherapy. The results of multiple studies indicate that chemotherapy combined with imatinib is well tolerated, induces complete hematological remission in almost every patient with newly diagnosed Ph+ ALL, and molecular remission in more than half of the cases. Future clinical studies need to focus on how imatinib can be incorporated into chemotherapy more effectively by determining the optimal dosage of imatinib, the optimal combinational schedule, and the role of allogeneic HSCT.

Adult acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia (ALL) in adults is a relatively rare neoplasm with a curability rate around 30% at 5 years. This consideration makes it imperative to dissect further the biological mechanisms of disease, in order to selectively implement an hitherto unsatisfactory success rate. The recognition of discrete ALL subtypes (some of which deserve specific therapeutic approaches, like T-lineage ALL (T-ALL) and mature B-lineage ALL (B-ALL)) is possible through an accurate combination of cytomorphology, immunophenotytpe and cytogenetic assays and has been a major result of clinical research studies conducted over the past 20 years. Two-three major prognostic groups are now easily identifiable, with a survival probability ranging from <10 to 20% (Philadelphia-positive ALL) to about 50-60% (low-risk T-ALL and selected patients with B-lineage ALL). These issues are extensively reviewed and form the basis of current knowledge. The second major point relates to the emerging importance of studies that reveal a dysregulated gene activity and its clinical counterpart. It is now clear that prognostication is a complex matter ranging from patient-related issues to cytogenetics to molecular biology, including the evaluation of minimal residual disease (MRD) and possibly gene array tests. On these bases, the role of a correct, highly personalised therapeutic choice will soon become fundamental. Therapeutic progress may be obtainable through a careful integration of chemotherapy, stem cell transplantation, and the new targeted treatments with highly specific metabolic inhibitors and humanised monoclonal antibodies.

The role of diagnosis in patients failing peripheral blood progenitor cell mobilization

BACKGROUND

Failure to mobilize PBPCs for auto-logous transplantation has mostly been attributed to previous therapy and poses therapeutic problems.

STUDY DESIGN AND METHODS

The role of underlying disease was analyzed in 17 of 73 (23%) patients with PBPC mobilization failure, and secondary mobilization with high-dose filgrastim was attempted.

RESULTS

Of 16 patients with acute leukemia, 13 (81%) mobilized poorly. In contrast, of 57 patients with non-Hodgkin's lymphoma, Hodgkin's lymphoma, multiple myeloma, and solid tumor, 53 (93%, p < 0.001) showed good PBPC mobilization. Relapsed disease did not predispose to poor mobilization. As secondary mobilization attempt, 7 patients received 25 micro g per kg per day filgrastim without chemotherapy leading to a 3.7 +/- 2.8-fold (SD) increase in the maximum number of circulating CD34+ cells (p = 0.104). PBPC apheresis yielded 3.3 (+/-0.5) x 10(6) CD34+ cells per kg of body weight in 5 patients. Four poor mobilizers received 50 micro g per kg per day filgrastim as second or third mobilization attempt. Circulating CD34+ cells in these patients increased by 1.5 (+/-0.7) compared with the primary G-CSF application.

CONCLUSION

Selective PBPC mobilization failure was seen in patients with acute leukemia whereas remarkably good mobilization was seen in other malignancies. Increasing the filgrastim dose to 25 micro g per kg per day may allow PBPC collection in patients failing PBPC mobilization.

Bone marrow transplant in Ph+ ALL patients

Although the outcome for Philadelphia positive (Ph+) acute lymphoblastic leukemia (ALL) with conventional chemotherapy is poor, the outcome after a sibling-matched allogeneic bone marrow transplantation (BMT) seems to be significantly better. The surprising success of allogeneic BMT may be because of disease response to high-dose chemotherapy combined with a graft-versus-leukemia effect. However, less than 30% of patients have a matched related donor available, and some of them will be too old/not fit for conventional BMT. While young patients who do not have a matched related donor should be considered for matched unrelated donor (MUD) transplant, older patients may be treated with autologous stem cell transplantation (ASCT) or rarely considered for a low-intensity MUD transplant. The efficacy of autologous BMT compared with chemotherapy is still debatable, although the new tyrosine kinase inhibitor Imatinib may be used for pretransplant purging/post-transplant therapy, aiming to improve autologous and allogeneic BMT results. The advantage of low-intensity sib/MUD allograft compared with chemotherapy is not proven either and is currently under investigation. However, if shown to be curative, low-intensity allograft may significantly improve the outcome of older Ph+ ALL patients, who are not eligible for conventional allograft.

Autologous stem cell transplantation and purging in adult acute lymphoblastic leukaemia

The prognosis for adult acute lymphoblastic leukaemia (ALL) is poor. Only 20-30% of patients will be cured with conventional chemotherapy. Haematopoietic progenitor transplantation is thus an attractive option in these patients. Even if allogeneic transplantation allows a better control of the disease, autologous transplantation remains an important alternative for patients lacking a suitable donor or when allogeneic transplants imply excessive risk. Relapse is the main drawback of autologous transplants, but many strategies are being explored to overcome this problem. We focus here on transplant modality, the source of haematopoietic progenitors, and the best timing to apply the procedure. Also reviewed are the current situation and future strategies for improving results in this setting, such as ex vivo purging; immunotherapy and maintenance chemotherapy.

New approaches to hematopoietic cell transplantation in oncology

The use of high-dose chemotherapy followed by autologous HCT and the use of allogeneic HCT in children and adolescents with high-risk ALL, AML, and NBL has successfully improved outcomes. For other diseases, however, the role of HCT in treatment remains a subject of further research. The availability of HCT was significantly expanded by developing alternative graft sources that currently include BM, peripheral blood, and UCB from autologous and allogeneic related or unrelated donors. Progress in autologous HCT has been achieved by the identification of more effective and less toxic preparative regimens and by ex vivo purging of stem cell products. In allogeneic HCT, graft-versus-leukemia or graft-versus-tumor effects are being exploited increasingly to lower relapse rates. In addition, immunomodulation to promote tolerance, as well as allogeneic antitumor reactions have been achieved by antibody therapy, cytokine therapy, or cell-based immunotherapy. Future improvements are likely, as evidenced by promising preliminary results in the development of stem cell collection techniques, in vitro stem cell expansion, and purging techniques of stem cell grafts. The development of less intensive or nonmyeloablative preparative regimens may further reduce regimen-related morbidity and mortality Specific immunotherapy may facilitate tolerance induction in mismatched allogeneic HCT and support allogeneic HCT in the setting of donor-host HLA disparity. Ultimately, advances in cytokine therapy, tumor-specific vaccines, and gene therapy may decrease or even eradicate recurrence of the malignant disease after HCT.

Risk-adapted treatment according to minimal residual disease in adult ALL

The evaluation of minimal residual disease (MRD) is a new diagnostic method which is applicable in various malignant disorders. Acute lymphoblastic leukaemia (ALL) is a somewhat ideal disease in this respect because >90% of the patients show individual clonal markers and because several methods for MRD evaluation are already established. Futhermore, it was demonstrated that level and course of MRD are significantly correlated with relapse risk in childhood and in adult ALL. In clinical practice MRD evaluation may serve for several purposes such as follow-up of individual course of disease, identification of new prognostic factors or evaluation of single treatment elements. We discuss these options as well as general considerations for MRD-based risk stratification and treatment options for risk groups. Practical applications are analysed because prospective MRD-based clinical trials have been recently started. Finally, future options for application of MRD evaluation and also limitations and pitfalls of this method are reviewed.

Autologous stem cell transplantation in acute lymphocytic leukemia

Autologous stem cell transplantation (ASCT) as well as allogeneic stem cell transplantation and conventional chemotherapy (CT) are less effective at treating acute lymphocytic leukemia (ALL) than acute myelocytic leukemia (AML). Chemoresistance and late relapses are hallmarks of ALL. In this context, the question of whether ASCT is superior to CT remains unanswered. In vitro marrow purging using monoclonal antibodies is not routinely used. This review summarizes the results of ASCT for adult and childhood ALL. Statistics from the European Group for Blood and Marrow Transplantation reveal a transplant-related mortality at 5 years of 11% +/- 1%, a relapse incidence of 60% +/- 2%, and a leukemia-free survival (LFS) and overall survival (OS) of 36% +/- 2% and 42% +/- 2%, respectively in 1,366 adults autografted in first remission (CR1). In 269 children, the LFS and OS were 50% +/- 3% and 54% +/- 3%, respectively. There was no evidence in favor of purging the autograft in vitro. In contrast, multicentric and single-institution studies have found better results in adults autografted in CR1, with LFS at 5 years from 46% to 64%, possible efficacy of marrow in vitro purging with mafosfamide (LFS 52%), and improvement in outcome with additional measures post-ASCT, such as maintenance chemotherapy (LFS 57%). Further, as already observed for AML, analyses by risk groups suggest that ASCT may essentially benefit good- but not poor-risk patients. For patients with the Ph1/bcr-abl translocation, the role of STI571 anti-tyrosine kinase for in vivo purging before stem cell harvesting is being investigated.

Autologous stem cell transplantation for acute lymphocytic leukemia in adults

Autologous bone marrow transplantation remains an investigational treatment for adult ALL. Despite many anecdotal studies showing efficacy, the rarity of ALL has prevented the large randomized trials necessary to confirm effectiveness. Candidates for autoBMT include adult patients in first CR with adverse risk factors and all patients who have experienced disease relapse. It remains debatable which preparative regimen is optimal, whether purging is necessary, or if chemotherapy or immunotherapy administered after transplantation can decrease disease relapse. Overall, every effort should be made to enter ALL patients on well-designed randomized multi-institutional trials. These trials should compare autologous transplantation to newer more intensive chemotherapy regimens and should take into account the heterogeneity of ALL. A quality of life analysis should be performed as one high-dose treatment may be less toxic and better tolerated than multiple cycles of consolidation chemotherapy. Strategies aimed at enhancing an autologous graft-versus-leukemia effect after transplantation may enhance long-term survival. Many more studies are needed to further define the optimal role of autoBMT in adult ALL.

Rituximab can be useful as treatment for minimal residual disease in bcr-abl-positive acute lymphoblastic leukemia

We report the results of administering CD20 monoclonal antibody (MoAb) in a 32-year-old man with bcr-abl-positive acute lymphoblastic leukemia. Morphological complete remission was achieved after two lines of chemotherapy with persistence of blast cells (2%) in flow cytometric analysis of marrow cells. Since no HLA-matched donor for allogeneic bone marrow transplantation (BMT) was found, anti-CD20 MoAb therapy was administered for in vivo marrow purging, prior to autologous peripheral blood stem cell (PBSC) harvest and transplantation. After MoAb therapy <0.1% of blast cells were observed and the molecular abnormality (bcr-abl gene rearrangement) disappeared.

Treatment of Adult ALL according to protocols of the German Multicenter Study Group for Adult ALL (GMALL)

The German Multicenter Study Group for Adult Acute Lymphoblastic leukemia (GMALL) has conducted 5 consecutive trials with more than 3000 patients since 1981. This article provides an overview on aims, treatment concepts, and results of these studies. It includes brief summaries on the development of prognostic models within the GMALL group and on approaches for prophylaxis of CNS relapse, and it summarizes specific treatment concepts for mature B-lineage acute lymphocytic leukemia.

Recent approaches in acute lymphoblastic leukemia in adults

In the past 20 years major advances in terms of biological characterisation and outcome of adult acute lymphoblastic leukemia (ALL) have been achieved. More recently there was no further improvement of overall results in larger prospective trials but significant advances for distinct biological subgroups of ALL such as mature B-ALL and T-ALL. The paper will give a brief review on the results of chemotherapy, indications and results of bone marrow transplantation and CNS prophylaxis in adult ALL. Furthermore it will characterise immunological subgroups of ALL and give an overview on well known prognostic factors and new parameters such as minimal residual disease (MRD). These risk factors are included in a suggested new risk model for adult ALL. Subtype adjusted therapy, rational treatment decisions based on MRD and new, 'causative' treatment approaches are highlighted as the most promising perspectives for future improvement of treatment results in adult ALL.