Hematopoietic Cell Transplantation for Benign Hematological Disorders and Solid Tumors

Hematological Parameters and Demographic Distribution of Hemoglobinopathies and Various Hemoglobin Variants

Background The study was conducted to find the prevalence of hemoglobinopathies along with their geographical/ethnic distribution to highlight the region of high prevalence that can be used to guide screening. Method Results of blood samples received for hemoglobin variants determination by high-performance liquid chromatography (HPLC) were retrospectively analyzed at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore. Blood samples were assayed for CBC (complete blood count), red blood cell morphology, and hemoglobin analysis by HPLC. CBC was performed on Sysmex XN 9000 analyzer (Sysmex, Kobe Japan), peripheral smears to review RBC morphology were stained with Wright-Giemsa stain, and HPLC was performed on BIO-RAD variant II (Bio-Rad Laboratories, Hercules, USA). Results Hemoglobinopathies were identified in 9.7% (n=997) out of 10,297 samples. Beta thalassemia trait was the most common hemoglobinopathy recognized with a prevalence of 5% (n=516), with the maximum number of cases in the Lahore district of Punjab province. The next most common hemoglobinopathy identified was sickle cell disease with a frequency of 1.43% (n=148) and the maximum cases from the Dera Ismail Khan district of the Khyber Pakhtunkhwa province. The additional important hemoglobinopathies found were sickle cell trait, hemoglobin-D Punjab trait, and compound heterozygote for sickle and beta thalassemia. Conclusion Hemoglobinopathies are the most common inherited disorders in Pakistan and worldwide. Screening for hemoglobinopathies is recommended in high-prevalence districts of Pakistan. Sickle cell screening is also recommended in newborns in the high prevalence area of Pakistan, such as the northwest regions.

In Vivo HSC Gene Therapy Using a Bi-modular HDAd5/35++ Vector Cures Sickle Cell Disease in a Mouse Model

We have recently reported that, after in vivo hematopoietic stem cell/progenitor (HSPC) transduction with HDAd5/35++ vectors, SB100x transposase-mediated γ-globin gene addition achieved 10%-15% γ-globin of adult mouse globin, resulting in significant but incomplete phenotypic correction in a thalassemia intermedia mouse model. Furthermore, genome editing of a γ-globin repressor binding site within the γ-globin promoter by CRISPR-Cas9 results in efficient reactivation of endogenous γ-globin. Here, we aimed to combine these two mechanisms to obtain curative levels of γ-globin after in vivo HSPC transduction. We generated a HDAd5/35++ adenovirus vector (HDAd-combo) containing both modules and tested it in vitro and after in vivo HSPC transduction in healthy CD46/β-YAC mice and in a sickle cell disease mouse model (CD46/Townes). Compared to HDAd vectors containing either the γ-globin addition or the CRISPR-Cas9 reactivation units alone, in vivo HSC transduction of CD46/Townes mice with the HDAd-combo resulted in significantly higher γ-globin in red blood cells, reaching 30% of that of adult human α and βS chains and a complete phenotypic correction of sickle cell disease.

The role of macrophages in the differentiation process of ureteral polyps

Objective

To evaluate the role of macrophage infiltration in the differentiation process of ureteral polyps and cancers.

Methods

This retrospective immunohistochemical study analysed archival samples of pathologically-confirmed specimens of low- and high-grade ureteral cancer, ureteral papilloma and ureteral polyps. The samples were immunohistochemically stained for cluster of differentiation (CD)4, CD8, CD16, CD25, CD56 and CD68 using immunofluorescence in order to identify different T-lymphocyte populations and macrophages.

Results

A total of 70 specimens were included in the analysis: 21 specimens of ureteral cancer, 17 specimens of ureteral papilloma, and 32 specimens of ureteral polyps. The largest proportion of CD4+CD25+ regulatory T cells was observed in the low-grade ureteral cancer group and almost none were observed in ureteral papillomas. The largest proportion of CD8+ cytotoxic T-lymphocytes was observed in the ureteral polyps. The largest proportion of CD56+ natural killer cells was detected in the ureteral polyps, with very low levels observed in the other three groups. The largest proportion of CD16+CD68+ macrophages was observed in the high-grade ureteral cancer group, which was significantly higher than that observed in the ureteral papillomas.

Conclusions

This study revealed that CD16+CD68+ macrophages appear to participate in ureteral neoplastic transformation.

Preclinical modeling of hematopoietic stem cell transplantation - advantages and limitations

Hematopoietic stem cell transplantation, which was first successfully performed in the 1950s, remains a critical therapeutic modality for treatment of a diverse array of diseases, including a multitude of hematological malignancies, autoimmune disorders, amyloidosis and inherited genetic hematological disorders. Although great advances have been made in understanding and application of this therapy, significant complications still exist, warranting further investigation. Of critical importance, graft-versus-host disease (GVHD), in both acute and chronic forms, remains a major complication of hematopoietic stem cell transplantation, responsible for both the development of chronic illness and morbidity, as well as mortality. Use of an appropriate preclinical model may provide significant insight into the mechanistic pathways leading to the development and progression of graft-versus-host disease, as well as cancer in general. However, existing preclinical modeling systems exhibit significant limitations, and development of models that recapitulate the complex and comprehensive clinical scenario and provide a tool by which therapeutic intervention may be developed and assessed is of utmost importance. Here, we review the present status of the field of graft-versus-host disease research. We discuss and summarize the preclinical models currently in use, as well as their advantages and limitations.

Twenty years of experience on stem cell transplantation in iran

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is a new window to therapy of many diseases. From March 1991 through April 2011, a total of 3237 HSCT were performed in the Hematology-Oncology and Stem Cell Transplantation Research Center, affiliated to Tehran University of Medical Sciences. Here we report 20 years experience of HSCT.

OBJECTIVES

Our strategy and aim include the protraction of cytogenetic and molecular biological diagnostic tests, the expansion of the first Iranian Cord Blood Bank (ICBB) and development of the first Iranian Stem Cell Donor Program (ISCDP), and improvement the researches in new therapeutic fields.

PATIENTS AND METHODS

Totally, 3237 patients were undergone HSCT. Of these transplants, 2205 were allogeneic stem cell transplantation, 1016 autologous and 16 syngeneic. Among 2205 patients who were undergone allogenic-HSCT, 34 received cord blood stem cells as stem cell source for transplantation. It is important to point out that cord blood bank at our center provides reliable storage of cord blood stem cells for our patients. Stem cell transplantation was performed for treatment of various diseases such as acute myelogenous leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, chronic lymphoblastic leukemia, beta-thalassemia major, sickle- cell thalassemia, sickle- cell disease, multiple myeloma, myelodysplasia, mucopolysaccharidosis, paroxysmal nocturnal hemoglobinuria, non-Hodgkin's lymphoma, Hodgkin's disease, severe aplastic anemia, plasma cell leukemia, Niemann-Pick disease, Fanconi anemia, severe combined immunodeficiency, congenital neutropenia, leukocyte adhesion deficiencies, Chediak-Higashi syndrome, osteopetrosis, histiocytosis X, Hurler syndrome, amyloidosis, systemic sclerosis, breast cancer, Ewing's sarcoma, testicular cancer, germ cell tumors, neuroblastoma, medulloblastoma, renal cell carcinoma, nasopharyngeal carcinoma, ovarian cancer, Wilms' tumor, rhabdomyosarcoma, pancreatoblastoma, and multiple sclerosis. Also, we had 220 cellular therapies for post-myocardial infarction, multiple sclerosis, cirrhosis, head of femur necrosis, Diabetes Mellitus and GvHD treatment. 45 patients were undergone retransplantation in this center.

RESULTS

About 78.2% of the patients (2530 of 3237) remained alive between one to 211 months after stem cell transplantation. Nearly, 21.8% (707) of our patients died after stem cell transplantation. The main causes of death were relapse, infection, hemorrhagic cystitis, graft-versus- host disease and etc.

CONCLUSIONS

In Iran, HSCT has been successfully adapted in routine clinical care. Recently, new methods such as double cord blood and haploidentical transplantation have been used to treat many life-threatening diseases.

The potential role of cell penetrating peptides in the intracellular delivery of proteins for therapy of erythroid related disorders

The erythroid related disorders (ERDs) represent a large group of hematological diseases, which in most cases are attributed either to the deficiency or malfunction of biosynthetic enzymes or oxygen transport proteins. Current treatments for these disorders include histo-compatible erythrocyte transfusions or allogeneic hematopoietic stem cell (HSC) transplantation. Gene therapy delivered via suitable viral vectors or genetically modified HSCs have been under way. Protein Transduction Domain (PTD) technology has allowed the production and intracellular delivery of recombinant therapeutic proteins, bearing Cell Penetrating Peptides (CPPs), into a variety of mammalian cells. Remarkable progress in the field of protein transduction leads to the development of novel protein therapeutics (CPP-mediated PTs) for the treatment of monogenetic and/or metabolic disorders. The “concept” developed in this paper is the intracellular protein delivery made possible via the PTD technology as a novel therapeutic intervention for treatment of ERDs. This can be achieved via four stages including: (i) the production of genetically engineered human CPP-mediated PT of interest, since the corresponding native protein either is missing or is mutated in the erythroid progenitor cell (ErPCs) or mature erythrocytes of patients; (ii) isolation of target cells from the peripheral blood of the selected patients; (iii) ex vivo transduction of cells with the CPP-mediated PT of interest; and (iv) re-administration of the successfully transduced cells back into the same patients.

Hemoglobinopathies: clinical manifestations, diagnosis, and treatment

BACKGROUND

Hemoglobinopathies are among the most common inherited diseases around the world. They have become much more common recently in northern and central Europe, including Germany, due to immigration.

METHOD

Selective review of the literature with consideration of national guidelines.

RESULTS

The hemoglobinopathies encompass all genetic diseases of hemoglobin. They fall into two main groups: thalassemia syndromes and structural hemoglobin variants (abnormal hemoglobins). α- and β-thalassemia are the main types of thalassemia; the main structural hemoglobin variants are HbS, HbE and HbC. There are many subtypes and combined types in each group. The highly variable clinical manifestations of the hemoglobinopathies range from mild hypochromic anemia to moderate hematological disease to severe, lifelong, transfusion-dependent anemia with multiorgan involvement. Stem-cell transplantation is the preferred treatment for the severe forms of thalassemia. Supportive, rather than curative, treatment consists of periodic blood transfusions for life, combined with iron chelation. Drugs to treat the symptoms of sickle-cell disease include analgesics, antibiotics, ACE inhibitors and hydroxyurea. Blood transfusions should be given only when strictly indicated. More than 90% of patients currently survive into adulthood. Optimally treated patients have a projected life span of 50 to 60 years.

CONCLUSION

Hemoglobinopathies are a public health issue in today's multiethnic German population. Adequate care of the affected patients requires a wide variety of diagnostic and therapeutic measures.

Controlled major histocompatibility complex-T cell receptor signaling allows efficient generation of functional, antigen-specific CD8+ T cells from embryonic stem cells and thymic progenitors

Generation of early T cells by coculturing stem cells on notch-ligand-expressing OP9 stromal cells (OP9-DL1) has been widely reported. However, further differentiation of these cells into mature, antigen-specific, functional T cells, without retroviral transduction of T cell receptors (TcRs), is yet to be achieved. In the thymic niche this differentiation is controlled by the interaction of developing TcRs with major histocompatibility (MHC) molecules on stromal cells. We hypothesized that by providing exogenous antigen-specific MHC/TcR signals, stem and progenitor cells could be engineered into functional, effector T cells specific for the same antigen. Here we demonstrate that both thymus-derived immature T cells (double positive [DP]: CD4+CD8+) and mouse embryonic stem cells can be efficiently differentiated into antigen-specific CD8+ T cells using either MHC tetramers or peptide-loaded stromal cells. DP cells, following MHC/TcR signaling, retained elevated recombination activating gene-1 levels, suggesting continuing TcR gene rearrangement. Both DP and embryonic stem-cell-derived CD8+ T cells showed significant cytotoxic T lymphocytes activity against antigen-loaded target cells, indicating that these cells are functional. Such directed differentiation strategy could provide an efficient method for generating functional, antigen-specific T cells from stem cells for potential use in adoptive T cell therapy.

Allogeneic haematopoietic stem cell transplantation: individualized stem cell and immune therapy of cancer

The year 2009 marked the fiftieth anniversary of the first successful allogeneic haematopoietic stem cell transplant (HSCT). The field of HSCT has pioneered some of the most exciting areas of research today. HSCT was the original stem cell therapy, the first cancer immune therapy and the earliest example of individualized cancer therapy. In this Timeline article we review the history of the development of HSCT and major advances made in the past 50 years. We highlight accomplishments made by researchers who continue to strive to improve outcomes for patients and increase the availability of this potentially life-saving therapy for patients with otherwise incurable malignancies.

Hematopoietic stem cell transplantation for hemoglobinopathies: current practice and emerging trends

Despite improvements in the management of thalassemia major and sickle cell disease, treatment complications are frequent and life expectancy remains diminished for these patients. Hematopoietic stem cell transplantation (HSCT) is the only curative option currently available. Existing results for HSCT in patients with hemoglobinopathy are excellent and still improving. New conditioning regimens are being used to reduce treatment-related toxicity and new donor pools accessed to increase the number of patients who can undergo HSCT.

Stable long-term donor engraftment following reduced-intensity hematopoietic cell transplantation for sickle cell disease

Reduced-intensity conditioning (RIC) regimens have the potential to decrease toxicities related to hematopoietic stem cell transplantation (HCT) in patients with sickle cell disease (SCD) and thus make HCT a more acceptable therapeutic option for this group of patients. We report the results of 7 patients enrolled on a study to evaluate safety and efficacy of HCT using bone marrow from an HLA matched sibling donor following an RIC regimen for patients with high-risk SCD. The conditioning regimen consisted of busulfan, fludarabine, equine antithymocyte globulin, and total lymphoid irradiation with shielding of the liver, lungs, heart, and gonads on day 1. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and mycophenolate mofetil. The regimen was well tolerated, and all patients had hematopoietic recovery. Six of 7 patients are stably engrafted off immunosuppression and without sickle cell-related symptoms at 2 to 8.5 years after HCT. Consistent with the complete resolution of SCD related symptoms observed in the 6 engrafted patients, erythropoiesis of complete or predominantly donor origin was detected by red blood cell-specific chimerism assays, despite their having persistent mixed chimerism in the mononuclear and lymphoid compartments. These findings demonstrate the curative potential of allogeneic HCT after an RIC regimen in patients with SCD.

Hematopoietic cell transplantation: a curative option for sickle cell disease

Sickle cell disease is associated with considerable morbidity and premature mortality. Hematopoietic cell transplantation offers the possibility of cure and is associated with excellent results in pediatric patients receiving stem cell transplantation from a matched sibling donor. Reduced intensity conditioning regimen have the potential to further reduce regimen related morbidity and mortality. Improved understanding of the natural history of complications such as stroke and pulmonary hypertension, effects of treatments, such as hydroxyurea and blood transfusions, as well as the impact of transplantation on organ damage are likely to influence the timing and indication of transplantation. Improvements in preparative regimen may enable the safe use of alternate source of stem cells such as unrelated matched donors and further improve the applicability and acceptability of this treatment.

Low-dose parenteral busulfan provides an extended window for the infusion of hematopoietic stem cells in murine hosts

OBJECTIVE

Myeloablative total body irradiation (TBI) in the setting of autologous transplantation of genetically modified hematopoietic stem cells (HSC) is associated with substantial toxicity. Nonmyeloablative doses of TBI are less toxic, but result in low-level engraftment of genetically modified HSCs. As an alternative to TBI, escalating doses of parenteral busulfan were tested for their hematologic toxicity, their ability to promote donor leukocyte engraftment, and the time window for such engraftment.

MATERIALS AND METHODS

Hematologic toxicity of busulfan was assessed in C57BL6 mice after single nonmyeloablative doses of intraperitoneal busulfan ranging from 1 to 40 mg/kg by serial complete blood counts monitored up to 40 days. The level of donor engraftment attainable after nonmyeloablative busulfan was determined by infusion of 20 million congenic murine bone marrow nucleated cells (BMNC) following 5 to 40 mg/kg of busulfan. To determine the effects of delayed HSC infusions, BMNCs were infused 1, 10, 15, and 20 days after a single dose of 10 mg/kg of busulfan.

RESULTS

Busulfan doses from 1 to 40 mg/kg produced hematologic toxicity that was most pronounced in the 2nd to 3rd week. In transplantation experiments, dose-dependent donor leukocyte engraftment was attained with levels >70% after only 20 mg/kg of busulfan. Similar levels of engraftment were achieved even when infusion of BMNCs was delayed up to 20 days after busulfan injection.

CONCLUSION

Nonmyeloablative parenteral busulfan produced transient myelosuppressive effects, clinically relevant levels of engraftment, and an extended time window for HSC infusion in murine hosts.

Hematopoietic cell transplantation for sickle cell disease: state of the art

Sickle cell disease is associated with considerable morbidity and premature mortality. Hematopoietic cell transplantation offers the possibility of cure and is associated with excellent results in pediatric patients receiving stem cell transplantation from a matched sibling donor. A reduced-intensity conditioning regimen has the potential to further reduce regimen-related morbidity and mortality. Improved understanding of the natural history of complications, such as stroke and pulmonary hypertension, effects of treatments such as hydroxyurea and blood transfusions, as well as the impact of transplantation on organ damage, are likely to influence the timing and indication of transplantation. Improvements in preparative regimens may enable the safe use of an alternative source of stem cells, such as unrelated matched donors, and further improve the applicability and acceptability of this treatment.

Reduced intensity conditioning for allogeneic hematopoietic cell transplantation: current perspectives

Allogeneic HCT after myeloablative conditioning is an effective therapy for patients with hematologic malignancies. In an attempt to extend this therapy to older patients or those with comorbidities, reduced intensity or truly nonmyeloablative regimens have been developed over the past decade. The principle underlying reduced intensity regimens is to provide some tumor kill with lessened regimen-related morbidity and mortality and then rely on graft-versus-tumor (GVT) effects to eradicate remaining malignant cells, whereas nonmyeloablative regimens rely primarily on GVT effects. In this article, 3 representative approaches are described, demonstrating the clinical application for hematopoietic and nonhematopoietic malignancies. Current challenges include controlling GVHD while allowing GVT to occur. In the future, clinical trials using reduced intensity and nonmyeloablative conditioning will be compared with myeloablative conditioning in selected malignancies to extend the application to standard-risk patients.

Unrelated bone marrow transplantation for beta-thalassemia patients: The experience of the Italian Bone Marrow Transplant Group

Bone marrow transplantation (BMT) remains the only potentially curative treatment for patients with thalassemia major. However, most candidates for BMT do not have a suitable family donor. In order to evaluate whether BMT from an HLA-matched unrelated volunteer donor can offer a probability of cure comparable to that obtained when the donor is a compatible sibling, we carried out a study involving 68 thalassemia patients transplanted in six Italian BMT Centers. Thirty-three males and 35 females (age range, 2-37 years; median age, 15) were transplanted from unrelated volunteer donors, all selected using high-resolution molecular typing of both HLA class I and II loci. Fourteen patients were classified in risk class 1; 16 in risk class 2; and 38 in risk class III of the Pesaro classification system. Nine patients (13%) had either primary or secondary graft failure. Fourteen patients (20%) died from transplant-related causes. Grade II-IV acute graft-versus-host disease (GVHD) developed in 24 cases (40%), and chronic GVHD in 10 cases (18%). Overall survival (OS) in the cohort of 68 patients was 79.3% (CI 67-88%), whereas the Kaplan-Meier estimates of disease-free survival (DFS) with transfusion independence was 65.8% (CI 54-77%). In the group of 30 thalassemic patients in risk classes 1 and 2, the probability of OS and DFS were 96.7% (CI 90-100%) and 80.0% (CI 65-94%), respectively, whereas in the 38 patients in class 3 OS was 65.2% (CI 49-80%) and DFS was 54.5% (CI 38-70%). These data show that when donor selection is based on stringent compatibility criteria, the results of unrelated transplantation in thalassemia patients are comparable to those obtained when the donor is a compatible sibling.

Overcoming graft rejection in heavily transfused and allo-immunised patients with bone marrow failure syndromes using fludarabine-based haematopoietic cell transplantation

Allogeneic haematopoietic cell transplantation (HCT) can cure a variety of non-malignant haematological disorders. Although transplant outcomes for selected patients with severe aplastic anaemia (SAA) and paroxysmal nocturnal haemoglobinuria (PNH) have improved, older age, allo-immunisation from transfusions, prior immunosuppressive therapy and a prolonged time from diagnosis to transplantation are associated with worse outcome. Because of its potent immunosuppressive effects, we investigated a fludarabine-based non-myeloablative conditioning regimen in patients with transfusion-dependent non-malignant haematological disorders at increased risk for graft rejection with conventional transplant conditioning. Twenty-six patients with transfusion dependent/anti-thymocyte globulin (ATG)-refractory SAA, PNH or pure red cell aplasia underwent HCT from a human leucocyte antigen (HLA)-compatible relative. Transplant conditioning consisted of cyclophosphamide (120 mg/kg) and fludarabine (125 mg/m2) with or without ATG. Ciclosporine, alone or combined with mycophenolate mofetil or methotrexate, was used as graft-versus-host disease (GVHD) prophylaxis. All patients achieved durable engraftment and transfusion-independence. Twenty-four of 26 patients are alive at a median of 21 months following transplantation. Although a high cumulative incidence of acute (65% grades II-IV, 54% grades III-IV) and chronic GVHD (56%) was observed, only one patient died from transplant-related causes (cumulative incidence 7%). These data show that HCT following fludarabine-based non-myeloablative conditioning results in durable engraftment and excellent survival in SAA and PNH patients at high risk for graft rejection.

Extracorporeal membrane oxygenation for support of children after hematopoietic stem cell transplantation: the Extracorporeal Life Support Organization experience

PURPOSE

Extracorporeal membrane oxygenation (ECMO) is a means of respiratory and hemodynamic support for patients failing conventional therapies. Children requiring hematopoietic stem cell transplantation who develop complications during therapy may require ECMO. Such patients pose medical and ethical challenges for clinicians considering initiation of ECMO. The authors review the outcomes of these patients and propose recommendations.

METHODS

The Extracorporeal Life Support Organization Registry was queried for all patients younger than 18 years with an International Classification of Diseases, Ninth Revision, or Current Procedural Terminology code related to bone or stem cell transplant.

RESULTS

Nineteen children in the registry met inclusion criteria. The median age was 9.6 years (7 months to 17.5 years). Initiation of ECMO was for pulmonary support (n = 17), cardiac support (n = 1), or cardiopulmonary resuscitation (n = 1). The median duration of ECMO support was 5.1 days (range, 30 hours to 42 days). Pulmonary infections included 3 parainfluenza, 2 Pneumocystis carinii, 1 influenza A, and 1 respiratory syncytial virus. Overall, 15 (79%) died during their ECMO run, whereas only 4 (21%) survived to come off ECMO. Furthermore, of those who survived their ECMO run, only one patient survived to discharge from the hospital. Risk factors for death on ECMO include development of renal complications and development of multiorgan dysfunction.

CONCLUSION

Patients who require ECMO for cardiopulmonary support after hematopoietic stem cell transplantation have a poor prognosis. Clinicians must be cautious in presenting this option to parents and present them with appropriate expectations in this high-risk population.

Stem cell transplantation in patients with chronic myelogenous leukemia: when should it be used?

Hematopoietic stem cell transplantation has been a cornerstone of therapy for chronic myelogenous leukemia (CML) for more than 15 years and is still a standard treatment option for patients with CML. The advent of imatinib mesylate, an inhibitor of the molecular defect driving CML, the BCR-ABL tyrosine kinase, has rewritten treatment algorithms for this disease and has shifted focus away from allografting. Despite advances in stem cell transplantation, such as broader availability with the use of modified conditioning regimens, use of allografting has diminished. Also, the nearly universal patient exposure to imatinib or other kinase inhibitors before transplantation may affect the biology of the disease that is currently being treated with an allograft and ultimately may affect outcomes. Exceedingly high rates of meaningful and stable response with longer follow-up continue to drive enthusiasm for imatinib use, and understanding of resistance mechanisms has driven rapid investigation of second-generation tyrosine kinase inhibitors to address imatinib failure and suboptimal response. In most patients, imatinib reduces CML to a minimal residual disease state in which options to further deepen remission, such as immunotherapy, are sought; monitoring techniques and interpretation of response advance in parallel to meet demands; and uncertainty remains as a new natural history of CML is defined in an era of kinase inhibitor therapy. This review summarizes the state of transplant and nontransplant therapy for CML and discusses the decision making for patients with an aim to optimize the use of our best therapies for CML in an era of uncertainty.

Reduced-Intensity Regimens in Allogeneic Hematopoietic Stem Cell Transplantation for Hemoglobinopathies

The only well-established curative therapy for patients with hemoglobinopathies is allogeneic hematopoietic stem cell transplantation (HSCT), which, in the last 20 years, has been mainly performed from an HLA-matched, related donor, using bone marrow as source of hematopoietic progenitors. More recent studies indicate that HSCT from unrelated donors may offer results comparable to those obtained with HLA-identical family donors, provided that stringent criteria of compatibility are employed for selecting the donor. Cord blood transplantation was also suggested to be an equally effective, but safer, procedure than bone marrow transplantation, due to the lower incidence and severity of both acute and chronic graft-versus-host disease. In view of the early, as well as late, morbidity and mortality associated with conventional myeloablative transplantation in patients with hemoglobinopathies, it is not surprising that great interest and relevant expectations for patients with hemoglobinopathies have been raised by the introduction in the clinical practice of reduced-intensity preparative regimens. However, few reports have demonstrated the feasibility of using reduced-intensity preparative regimens for successfully treating these patients and many treatment failures, mainly due to the lack of sustained donor engraftment, have been reported. Despite these limitations, some of the concepts obtained from the use of reduced intensity regimens, such as the substitution of fludarabine for cyclophosphamide, may be important to further improve the outcome of patients with hemoglobinopathies, especially of those with poor prognostic characteristics, given HSCT.

Autologous hematopoietic stem cell transplantation for autoimmune diseases

Experimental data and early phase I/II studies suggest that high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (HSCT) can arrest progression of severe autoimmune diseases. We have evaluated the toxicity and disease response in 473 patients with severe autoimmune disease treated with autologous HSCT between 1995 and 2003, from 110 centers participating in the European Group for Blood and Marrow Transplantation (EBMT) autoimmune disease working party database. Survival, transplant-related mortality, treatment response and disease progression were assessed. In all, 420 patients (89%; 86+/-4% at 3 years, median follow-up 20 months) were alive, 53 (11%) had died from transplant-related mortality (N=31; 7+/-3% at 3 years) or disease progression (N=22; 9+/-4% at 3 years). Of 370 patients, 299 evaluable for response (81%) showed a treatment response, which was sustained in 213 (71% of responders). Response was associated with disease (P<0.001), was better in patients who received cyclophosphamide during mobilization (relative risk (RR)3.28 (1.57-6.83)) and was worse with increasing age (>40 years, RR0.29 (0.11-0.82)). Disease progression was associated with disease (P<0.001) and conditioning intensity (high intensity, RR1; intermediate intensity, RR1.81 (0.96-3.42)); low intensity, RR2.34 (1.074-5.11)). These data from the collective EBMT experience support the hypothesis that autologous HSCT can alter disease progression in severe autoimmune disease.

Nonmyeloablative stem cell transplantation in metastatic renal cell carcinoma: delayed graft-versus-tumor effect is associated with chimerism conversion but transplantation has high toxicity

Seven out of 29 patients with metastatic renal cell carcinoma (RCC) considered eligible for allogeneic stem cell transplantation underwent nonmyeloablative stem cell transplantation (NST) from HLA-identical donors. Conditioning comprised cyclophosphamide, fludarabine and antithymocyte globulin. Prolonged mixed chimerism (MC) after engraftment converted to complete donor chimerism (CC) after infusion of donor lymphocytes and/or graft-versus-host disease (GvHD) in six patients. Five patients developed severe GvHD. Two of seven patients had a delayed tumor response after conversion to CC. After a median follow-up of 10 months (4-24 months), 5/7 patients are alive, one in very good partial remission (PR), one with stable and three with progressive disease. One of the seven patients died from sepsis in PR and 1/7 died from rapid tumor progression after sustained MC. None of the 22 nontransplanted patients responded to further therapies. Survival after 1 year was 59% in transplanted and 66% in nontransplanted patients (n.s.). A pooled data analysis from the literature suggests a graft-versus-tumor effect after transplant in patients with metastatic RCC, which becomes effective after chimerism conversion. Available data demonstrate high nonrelapse mortality in these patients. NST in RCC still has to be regarded as an investigational approach requiring careful patients' selection and longer follow-up within clinical studies.

Allogeneic stem-cell transplantation for renalcellcancer

Metastatic renal-cell carcinoma (RCC) is resistant to chemotherapy, and patients with this disease have a poor outlook. Immunotherapy by use of cytokines and vaccines against tumour antigens has shown encouraging results in a small group of patients. Advances in the understanding of the graft-versus-tumour effect in haematological malignant disorders have led to the use of stem-cell transplantation for treatment of solid-organ malignant diseases such as RCC. Techniques of bone-marrow ablation have been superseded by safer conditioning regimens, with occasional complete remission and partial remission in some patients. Graft-versus-host disease, engraftment failure, and disease progression remain important obstacles to the widespread use of new techniques for metastatic RCC. Here, we summarise important issues surrounding immunotherapy for RCC, the problems encountered with use of immunotherapy, and the present use of non-myeloablative techniques for treatment of this disease.

Allogeneic hematopoietic cell transplantation as treatment for hematological malignancies: a review

Allogeneic hematopoietic cell transplantation (HCT) was originally developed as a form of rescue from high-dose chemoradiotherapy, which is given both to eradicate malignancy and provide sufficient immunosuppression for allogeneic engraftment. The first attempts of allogeneic HCT in humans met with little success. However, a better understanding of the complexities of the human leukocyte antigen (HLA) system has allowed selecting compatible sibling donors, and the development of postgrafting immunosuppressive regimens has helped prevent serious graft-versus-host disease, thereby changing the role of allogeneic HCT from a desperate therapeutic maneuver to a curative treatment modality for many patients with malignant hematological diseases. In addition, the establishment of large registries of HLA-typed volunteers has permitted finding suitable unrelated donors for many patients without family donors. Further advances in the immunogenetics of HLA, especially typing by molecular techniques, have improved results after unrelated HCT, which have begun resembling those obtained with HLA-identical sibling grafts, at least in young patients. Important advances have also been made in the prevention and treatment of infectious complications and in other areas of supportive care. Since the late seventies, it has been recognized that allogeneic immunocompetent cells transplanted with the stem cells, or arising from them, mediated therapeutic anti-tumor effects independent of the action of the high-dose therapy, termed graft-versus-tumor (GVT) effects. This has prompted the recent development of non-myeloablative conditioning regimens for allogeneic HCT that have opened the way to include elderly patients and those with comorbid conditions. Remaining challenges include further advances in the prevention and treatment of both severe graft-versus-host disease and infections. Also, progress in adoptive transfer of T cells with relative tumor specificity and disease-targeted therapy with agents such as Imatinib, Rituximab or radiolabeled monoclonal antibodies would make allogeneic HCT even more effective.

Allogeneic hematopoietic stem cell transplantation with a reduced-intensity conditioning regimen for treatment of metastatic renal cell carcinoma: single institution experience with a minimum 1-year follow-up

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of allogeneic hematopoietic stem cell transplantation with a reduced-intensity conditioning regimen (RIST) for interferon-alpha-refractory metastatic renal cell carcinoma (RCC).

PATIENTS AND METHODS

Of 26 patients referred to the National Cancer Center Hospital for possible RIST between June 2000 and April 2002, an HLA-identical relative was identified for 12 patients. Nine patients underwent RIST. The conditioning regimen consisted of fludarabine 180 mg/m2 or cladribine 0.66 mg/kg, plus busulfan 8 mg/kg and rabbit antithymocyte globulin 5 mg/kg. Graft-vs-host disease (GVHD) prophylaxis was cyclosporine alone.

RESULTS

All patients achieved engraftment without grade III to IV nonhematologic regimen-related toxicity. All patients achieved complete donor-type chimerism without donor lymphocyte infusion by day 60. Four patients developed acute GVHD, and four developed chronic GVHD. One patient (11%) achieved partial response. As of July 2003, six patients were alive at median follow-up of 681 days. The actuarial overall survival rate was 89% at 1 year and 74% at 2 years. The overall survival rate tended to be higher in the 12 patients with a matched donor than in the other 14 patients without a matched donor (p = 0.088).

CONCLUSION

Our RIST procedure is feasible without severe toxicity. The efficacy of RIST for RCC should be confirmed in phase II/III clinical trials.

Haematopoietic stem cell transplantation for autoimmune disease: limits and future potential

Stem cell transplantation (SCT) for autoimmune disease is handicapped by a lack of definitive clinical trials able to demonstrate an overall benefit. This deficiency will become more problematic as the impetus grows to introduce and evaluate additional technologies intended to improve the safety and efficacy of the procedure. The development of effective surrogate analyses to predict outcome by measuring resurgent autoimmune clones or by genomic- and proteomic-based technologies to detect early disease recurrence may be of value in assessing the benefits of these modifications without the need for full-scale, long-term, randomized trials. The introduction of safer allogeneic transplantation techniques may increase the effectiveness of the procedure, while work on marrow stem cell plasticity and/or fusion suggests that SCT may serve not simply to halt the autoimmune process, but also to contribute cells capable of healing or regenerating diseased organs. Finally, the introduction of therapeutic transgenes into transplanted cells may further increase the effectiveness of SCT, although the regulatory complexities of gene therapy trials will probably delay this process. All these innovations will ensure that the next decade will see major changes in the practice and purpose of SCT for autoimmune disease.