Autologous hematopoietic stem cell transplantation in refractory rheumatoid arthritis: sustained response in two of four patients

Cell-based therapies for the treatment of rheumatoid arthritis

Autoimmune diseases, including rheumatoid arthritis that is the most prevalent rheumatic autoimmune disorder, affect autologous connective tissues caused by the breakdown of the self-tolerance mechanisms of the immune system. During the last two decades, cell-based therapy, including stem cells and none-stem cells has been increasingly considered as a therapeutic option in various diseases. This is partly due to the unique properties of stem cells that divide and differentiate from the specialized cells in the damaged tissue. Moreover, stem cells and none-stem cells, impose immunomodulatory properties affecting the diseases caused by immunological abnormalities such as rheumatic autoimmune disorders. In the present review, the efficacy of cell-based therapy with four main types of stem cells, including mesenchymal stem cells, hematopoietic stem cells, embryonic stem cells, and human amniotic membrane cells, as well as none-stem cells, including regulatory T cells, chimeric antigen receptor T cells, and tolerogenic dendritic cells will be evaluated. Moreover, other related issues, including safety, changes in immunological parameters, suitable choice of stem cell and none-stem cell origin, conditioning regimen, limitations, and complications will be discussed.

Current State and Issues of Regenerative Medicine for Rheumatic Diseases

The prognosis of rheumatic diseases is generally better than that of malignant diseases. However, some cases with poor prognoses resist conventional therapies and cause irreversible functional and organ damage. In recent years, there has been much research on regenerative medicine, which uses stem cells to restore the function of missing or dysfunctional tissues and organs. The development of regenerative medicine is also being attempted in rheumatic diseases. In diseases such as systemic sclerosis (SSc), systemic lupus erythematosus (SLE), and rheumatoid arthritis, hematopoietic stem cell transplantation has been attempted to correct and reconstruct abnormalities in the immune system. Mesenchymal stem cells (MSCs) have also been tried for the treatment of refractory skin ulcers in SSc using the ability of MSCs to differentiate into vascular endothelial cells and for the treatment of systemic lupus erythematosus SLE using the immunosuppressive effect of MSCs. CD34-positive endothelial progenitor cells (EPCs), which are found in the mononuclear cell fraction of bone marrow and peripheral blood, can differentiate into vascular endothelial cells at the site of ischemia. Therefore, EPCs have been used in research on vascular regeneration therapy for patients with severe lower limb ischemia caused by rheumatic diseases such as SSc. Since the first report of induced pluripotent stem cells (iPSCs) in 2007, research on regenerative medicine using iPSCs has been actively conducted, and their application to rheumatic diseases is expected. However, there are many safety issues and bioethical issues involved in regenerative medicine research, and it is essential to resolve these issues for practical application and spread of regenerative medicine in the future. The environment surrounding regenerative medicine research is changing drastically, and the required expertise is becoming higher. This paper outlines the current status and challenges of regenerative medicine in rheumatic diseases.

The Outcome of Stem Cell-Based Therapies on the Immune Responses in Rheumatoid Arthritis

Rheumatoid arthritis as a common autoimmune inflammatory disorder with unknown etiology can affect 0.5-1% of adults in developed countries. It involves more than just the patient's joints and can be accompanied by several comorbidities and affect cardiovascular, pulmonary, and some other systems of the human body. Although cytokine-mediated pathways are mentioned to have a central role in RA pathogenesis, adaptive and innate immune systems and intracellular signaling pathways all have important roles in this process. Non-steroidal anti-inflammatory drugs, glucocorticoids, conventional disease-modifying anti-rheumatic drugs, and biological agents are some mentioned medications used for RA. They are accompanied by some adverse effects and treatment failures which elucidates the needing for novel and more powerful therapeutic approaches. Stem cell-based therapies and their beneficial effects on therapeutic processes of different diseases have been founded so far. They can be an alternative and promising therapeutic approach for RA, too; due to their effects on immune responses of the disease. This review, besides some explanations about RA characteristics, addresses the outcome of the stem cell-based therapies including mesenchymal stem cell transplantation and hematopoietic stem cell transplantation for RA and explains their effects on the disease improvement.

Hematopoietic stem cell therapy for autoimmune diseases - Clinical experience and mechanisms

With accumulating evidence and improved outcomes along with recognition that modern biological therapies are not universally effective, require chronic administration and have high acquisition costs, hematopoietic stem cell transplantation (HSCT) has become an emerging direction for cell therapy in autoimmune diseases (ADs). The goal of this therapy is to induce medication-free remissions by resetting the immune system into a naïve and self-tolerant state through eradication of the autoreactive immunologic memory and profound re-configuration of the immune system induced by the transplant procedure. Safety of HSCT has generally improved by implementing internal quality management and external accreditation. Inter-disciplinary guidelines for patient selection, transplant technique and supportive care along with greater center experience should optimize safe and appropriate delivery of HSCT in specific ADs. In this review, we discuss the current role and future perspectives of HSCT in AD, focusing on recent published clinical and scientific studies and recommendations in the field.

Immunological characteristics and T-cell receptor clonal diversity in children with systemic juvenile idiopathic arthritis undergoing T-cell-depleted autologous stem cell transplantation

Children with systemic Juvenile Idiopathic Arthritis (sJIA), the most severe subtype of JIA, are at risk from destructive polyarthritis and growth failure, and corticosteroids as part of conventional treatment can result in osteoporosis and growth delay. In children where there is failure or toxicity from drug therapies, disease has been successfully controlled by T-cell-depleted autologous stem cell transplantation (ASCT). At present, the immunological basis underlying remission after ASCT is unknown. Immune reconstitution of T cells, B cells, natural killer cells, natural killer T cells and monocytes, in parallel with T-cell receptor (TCR) diversity by analysis of the β variable region (TCRVb) complementarity determining region-3 (CDR3) using spectratyping and sequencing, were studied in five children with sJIA before and after ASCT. At time of follow up (mean 11·5 years), four patients remain in complete remission, while one child relapsed within 1 month of transplant. The CD8⁺ TCRVb repertoire was highly oligoclonal early in immune reconstitution and re-emergence of pre-transplant TCRVb CDR3 dominant peaks was observed after transplant in certain TCRVb families. Further, re-emergence of pre-ASCT clonal sequences in addition to new sequences was identified after transplant. These results suggest that a chimeric TCR repertoire, comprising T-cell clones developed before and after transplant, can be associated with clinical remission from severe arthritis.

Advancements in gene transfer-based therapy for hemophilia A

Gene therapy has promised clinical benefit to those suffering with hemophilia A, but this benefit has not yet been realized. However, during the past two decades, basic and applied gene therapy research has progressed and the goal of gene therapy for hemophilia A is once again in our sights. The hemophilia A patient population suffers from a disease that requires invasive, lifelong management, is exorbitantly expensive to treat, has geographically limited treatment access and can become untreatable due to immune reactions to the treatment product. Subsequent to the cloning of the factor VIII gene and cDNA in the early 1980s, academic and commercial research laboratories began to pursue gene transfer-based therapies to supplement or supplant the available protein replacement therapy. However, to date, clinical trials for gene therapy of hemophilia A have been unsuccessful. Three trials have been conducted with each having tested a different gene-transfer strategy and each demonstrating that there is a considerable barrier to achieving sustained expression of therapeutic amounts of factor VIII. Recent progress has been made in gene-transfer technology and, relevant to hemophilia A, towards increasing the biosynthetic efficiency of factor VIII. These advances are now being combined to develop novel strategies to treat and possibly cure hemophilia A.

The use of stem cells for the treatment of autoimmune diseases

Autoimmune diseases constitute a heterogeneous group of conditions commonly treated with anti-inflammatory, immunosuppressant and immunomodulating drugs, with satisfactory results in most cases. Nevertheless, some patients become resistant to conventional therapy. The use of high doses of drugs in such cases results in the need for bone marrow reconstitution, a situation which has stimulated research into the use of hematopoietic stem cells in autoimmune disease therapy. Stem cell transplantation in such diseases aims to destroy the self-reacting immune cells and produce a new functional immune system, as well as substitute cells for tissue damaged in the course of the disease. Significant results, such as the reestablishment of tolerance and a decrease in the recurrence of autoimmune disease, have been reported following stem cell transplantation in patients with autoimmune disease in Brazil and throughout the world. These results suggest that stem cell transplantation has the potential to become an important therapeutic approach to the treatment of various autoimmune diseases including rheumatoid arthritis, juvenile idiopathic arthritis, systemic lupus erythematosus, multiple sclerosis, systemic sclerosis, Crohn's disease, autoimmune blood cytopenias, and type I diabetes mellitus.

Hematopoietic stem cells encoding porcine factor VIII induce pro-coagulant activity in hemophilia A mice with pre-existing factor VIII immunity

The development of inhibitory antibodies directed against factor VIII (fVIII) remains the most significant clinical complication associated with the treatment of hemophilia A. Recently, we demonstrated that transplantation of genetically modified hematopoietic stem cells containing a high-expression porcine fVIII transgene promoted sustained high-level fVIII expression in naïve hemophilia A mice. In the current study, a similar gene transfer strategy was tested in hemophilia A mice harboring clinically significant anti-human factor VIII (anti-hfVIII) inhibitory antibody titers. Although the majority of mice contained circulating antibodies that cross-reacted with and inhibited porcine fVIII activity, transplantation of genetically modified hematopoietic stem cells containing a porcine fVIII transgene into myeloablated hemophilia A mice induced high-level fVIII activity. Furthermore, anti-hfVIII antibody titers steadily declined throughout the course of the study. However, non-myeloablative transplantation conditioning resulted in only partial success. No correlation between pre-transplantation antibody titers and post-transplantation fVIII activity levels or donor cell engraftment was observed. These data suggest that hematopoietic stem cell transplantation-based gene therapy incorporating a high-expression porcine fVIII transgene can be utilized successfully to treat hemophilia A patients harboring anti-hfVIII inhibitors.

Development of a secondary autoimmune disorder after hematopoietic stem cell transplantation for autoimmune diseases: role of conditioning regimen used

Patients undergoing autologous hematopoietic stem cell transplantation (auto-HSCT) for autoimmune disease may have an added propensity to develop a second autoimmune disorder, given the genetic predisposition to autoimmunity. Therefore, we undertook a retrospective analysis of all patients who have undergone auto-HSCT for an autoimmune disease in our institution to determine the occurrence of a second autoimmune disorder and possible risk factors. In all, 155 patients underwent auto-HSCT for various autoimmune diseases; of those patients, 6 manifested a distinct secondary autoimmune disease at a median of 8.5 months (range, 2-30 months) after auto-HSCT. There were 2 patients with systemic lupus erythematosus, conditioned with a regimen containing antithymocyte globulin (ATG), who developed factor VIII inhibitors with severe bleeding. There were 4 patients (2 with multiple sclerosis, one each with lupus and systemic sclerosis) who received an alemtuzumab-containing conditioning regimen who developed autoimmune cytopenias. Among the 155 patients, the frequency of secondary autoimmune complications was 16.0% with alemtuzumab (4/25), 1.9% for ATG (2/102), and 0% for conditioning regimens without lympho-depleting antibodies (0/28)-a difference that was found to be significantly higher with alemtuzumab exposure (P = .011). In contrast, sex, type of ATG used, and CD34-selection of peripheral blood stem cells were not found to be significantly associated with development of a secondary autoimmune disorder.

Immunoregulatory effects of allogeneic mixed chimerism induced by nonmyeloablative bone marrow transplantation on chronic inflammatory arthritis and autoimmunity in interleukin-1 receptor antagonist-deficient mice

OBJECTIVE

To investigate the immunoregulatory effects of allogeneic mixed chimerism induced by T cell-depleted, nonmyeloablative bone marrow transplantation (BMT) on chronic inflammatory arthritis and autoimmunity in mice deficient in interleukin-1 receptor antagonist (IL-1Ra).

METHODS

IL-1Ra(-/-) mice (H-2K(d)) were treated with antibody to asialoganglioside G(M1) (anti-natural killer cell), total body irradiation (500 cGy), and T cell-depleted, nonmyeloablative BMT derived from C57BL/6 mice (H-2K(b)). Engraftment and chimerism were evaluated in peripheral blood, lymph nodes, and spleen by multicolor flow cytometry. The severity of arthritis was evaluated by clinical scoring and histopathologic assessment. Levels of IgG1 and IgG2a subtypes of anti-type II collagen (anti-CII) antibodies were measured in serum samples. After T cells were stimulated with CII, ovalbumin, and phytohemagglutinin, T cell proliferative responses and levels of cytokine production (interferon-gamma [IFNgamma], tumor necrosis factor alpha [TNFalpha], interleukin-10 [IL-10], and IL-17) were assayed in culture supernatants.

RESULTS

All IL-1Ra(-/-) mice receiving BMT showed marked improvement in arthritis within 3 weeks, as well as successful induction of mixed chimerism. These mice showed higher levels of IgG1, and lower levels of IgG2a anti-CII antibodies and weaker T cell proliferative responses than did mice in the control groups (either no treatment or conditioning alone without bone marrow rescue). In mixed chimeras, the levels of IFNgamma, TNFalpha, and IL-17 produced from CII-stimulated T cells were significantly suppressed and IL-10 production was significantly higher as compared with controls.

CONCLUSION

The introduction of allogeneic mixed chimerism showed a strong immunoregulatory potential to correct established chronic inflammatory arthritis and autoimmunity originating from a dysregulated proinflammatory cytokine network.

Outcome of intensive immunosuppression and autologous stem cell transplantation in patients with severe rheumatoid arthritis is associated with the composition of synovial T cell infiltration

OBJECTIVE

To determine clinical and immunological correlates of high dose chemotherapy (HDC) + autologous stem cell transplantation (ASCT) in patients with severe rheumatoid arthritis (RA), refractory to conventional treatment.

METHODS

Serial samples of peripheral blood and synovial tissue were obtained from seven patients with RA treated with HDC and autologous peripheral blood grafts enriched for CD34+ cells. Disease activity was assessed with the Disease Activity Score (DAS), serum concentrations of C reactive protein (CRP), and human immunoglobulin (HIg) scans, and the extent of immunoablation was determined by immunophenotyping of peripheral blood mononuclear cells, and immunohistochemistry and double immunofluorescence of synovium.

RESULTS

Clinical responders (n = 5) had a larger number of cells at baseline expressing CD3, CD4, CD27, CD45RA, CD45RB, and CD45RO in synovium (p < 0.05), higher activity on HIg scans (p = 0.08), and a trend towards higher concentrations of CRP in serum than non-responders (n = 2). Subsequent remissions and relapses in responders paralleled reduction and re-expression, respectively, of T cell markers. A relatively increased expression of CD45RB and CD45RO on synovial CD3+ T cells was seen after HDC + ASCT. No correlations were found between DAS and changes in B cells or macrophage infiltration or synoviocytes.

CONCLUSIONS

HDC + ASCT results in profound but incomplete immunoablation of both the memory and naïve T cell compartment, which is associated with longlasting clinical responses in most patients. The findings provide strong circumstantial evidence for a role of T cells in established RA, and demonstrate a role for the synovium in post-transplantation T cell reconstitution.

Haemopoietic stem cell transplantation in autoimmune diseases: a European perspective

The potential of haemopoietic stem cell transplantation (HSCT) for the treatment of autoimmune and inflammatory diseases was originally supported by almost three decades of animal experiments and by the serendipitous remissions of autoimmune disease observed in patients undergoing transplantation for haematological disorders. Improved safety of both autologous and allogeneic HSCT over the last decade has been followed by increasing acceptance of HSCT as an experimental treatment for severe autoimmune diseases that are resistant to conventional treatment. International databases have collated over 700 procedures performed specifically for a variety of autoimmune diseases. Phase III clinical trials are in progress for some diseases. This review provides a comprehensive update on the efficacy and toxicity of HSCT in severe autoimmune disease. Future directions in the context of other evolving therapies are discussed.

Stem cell transplantation in autoimmune diseases: an update

Immunosuppressive or immunomodulatory treatments are often used in patients with various autoimmune diseases (AID). However, since conventional treatments are rarely curative, alternative treatment methods have been looked for. Based on animal experiments and anecdotal case reports, stem cell transplantation (SCT) has received considerable attention in the treatment of severe autoimmune diseases during the last decade. This review summarizes current experience of SCT in patients this field. Although early experience shows some promise, randomized studies are necessary to evaluate the real value of autologous SCT in various autoimmune diseases. Since autologous SCT may not be curative in patients with AID, also evaluation of allogeneic SCT is important in the future.

Non-myeloablative stem cell transplantation for autoimmune diseases

Treatment of life-threatening autoimmune diseases in animal models with induced or spontaneous autoimmune diseases can be accomplished by a 2-step procedure involving elimination of self-reactive lymphocytes with an immune ablative conditioning regimen followed by infusion of autologous or allogeneic stem cells, respectively. In animal models it was shown that using such a strategy, autoimmunity could be adequately controlled. It is speculated that de-novo development of the T and B cell repertoire from uncommitted progenitor cells in the presence of the autoantigens may be the best recipe for re-induction of self-tolerance, similarly to the normal ontogeny of the immune system during the induction of self tolerance in fetal stage. For both autologous and allogeneic hematopoietic stem cell transplantation, a non-myeloablative stem cell transplantation (NST) regimen may be used for safer lymphoablation rather than myeloablation. In addition, for allogeneic hematopoietic stem cell transplantation engraftment of disease resistant donor stem cells will alter the genetic predisposition towards autoimmune disease susceptibility.

Haematopoietic stem cell transplantation for autoimmune disorders: the American perspective

The hypothesis that haematopoietic stem cell transplantation (HSCT) might be useful in treating refractory autoimmune diseases (AID) was suggested by studies in animal models and by the improvement of concurrent autoimmune diseases in patients who had undergone transplantation for haematological disorders. This concept has now been tested in a substantial number of phase I/II clinical trials of autologous HSCT. These early results are promising, even in patients who have failed on multiple standard therapies for AID. Transplantation-related toxicity has decreased with growing experience in the application of this procedure, better patient selection and the modification of treatment protocols. Randomized trials currently under way or under consideration should clarify the role of HSCT in patients with autoimmune disorders.

Rheumatoid arthritis

Haematopoietic stem cell transplantation (HSCT) is now being investigated as a potential therapy for patients with severe refractory rheumatoid arthritis unresponsive to conventional therapies, including tumour necrosis factor-alpha blockade. Pilot studies and an analysis of worldwide cases included in the European Group for Blood and Marrow Transplantation/Autologous Blood and Marrow Transplant Registry registry have enabled the progression of the technique. HSCT is well tolerated in patients with rheumatoid arthritis, and there has been no transplant-related mortality. Although HSCT is not a cure, an improved response to previously ineffective therapies is often seen. Further research is, however, required, and this procedure is still considered appropriate only for those patients for whom there is no reasonable therapeutic alternative. This paper reviews all the previous data relating to HSCT in rheumatoid arthritis, outlines the current stand and discusses future protocol options and research.

Induction of remission of severe and refractory rheumatoid arthritis by allogeneic mixed chimerism

This report describes the first allogeneic hematopoietic stem cell transplantation (HSCT) performed for the indication of rheumatoid arthritis (RA). We used nonmyeloablative allogeneic HSCT to treat a 52-year-old woman who had treatment-refractory RA and a poor prognosis (24 swollen and 38 involved joints). She was treated with fludarabine, cyclophosphamide, CAMPATH-1H, and CD34-selected HSCT (8 million CD34+ donor cells/kg); the donor was the patient's HLA-matched, rheumatoid factor-negative sister. One year post-HSCT, the patient has had no infection except dermatomal varicella-zoster virus infection and no acute or chronic graft-versus-host disease (GVHD). Her RA has remained in remission with no immunosuppressive or immunomodulatory medications. The patient is a mixed chimera, with 55% donor T (CD3+) cells and 70% donor myeloid (CD33+) cells. This is the first published report of allogeneic HSCT performed for the indication of RA. Mixed chimerism has resulted in marked amelioration of RA, without GVHD.

Early recurrence of rheumatoid arthritis after nonmyeloablative allogeneic blood stem cell transplantation in a patient with multiple myeloma

Allogeneic blood stem cell transplantation with reduced conditioning has been proposed as a new, potentially curative treatment option for patients with rheumatoid arthritis (RA). We report a 60-year-old woman with RA and coexisting multiple myeloma who was treated with high-dose melphalan and autologous blood stem cell transplantation (BSCT) followed by a nonmyeloablative allogeneic BSCT from her healthy dizygotic twin brother. She achieved a complete remission of her RA after autologous BSCT, but relapsed early despite complete donor chimerism following successful allogeneic transplantation with reduced intensity conditioning. This case illustrates that allogeneic BSCT following nonmyeloablative conditioning may be an uncertain option for curing patients with RA.

Transduction of hematopoietic stem cells with a retroviral vector expressing the neomycin phosphotransferase gene

Transduction of stem cells with a marking gene holds promise to determine if tissue repair or regeneration is derived from the adult hematopoietic stem cell and if relapse of an autoimmune disease should occur whether relapse arises from the stem cell compartment or from lymphocytes surviving the conditioning regimen. New safety concerns about gene-modified stem cell would entail new safety testing such as documentation of the insertional site prior to release.

Hematopoietic stem cell transplantation for severe rheumatoid arthritis

The substantial morbidity and mortality associated with rheumatoid arthritis (RA), while not widely appreciated, provide adequate justification for consideration of high-dose immunoablative therapy followed by hematopoietic stem cell transplantation. While some patients with RA follow a benign course, selected subsets of patients have been identified with 5-year survival rates of 40-70%. A number of factors that can be easily determined serve as useful prognostic indicators for poor outcome. These include the presence of many involved joints (total joint count), the degree of functional disability as measured by the health assessment questionnaire and the presence of rheumatoid factor. This article summarises the present status of hematopoietic stem cell transplantation for rheumatoid arthritis and proposes future directions for research.

Intense immunosuppression and stem-cell transplantation for patients with severe rheumatic autoimmune disease: a review

BACKGROUND

Intense immunosuppression plus stem-cell transplantation (SCT) has emerged as a new treatment modality for patients with refractory, severe rheumatic autoimmune disease. Its rationale is based on eliminating autoaggressive lymphocytes by lympho- or myeloablative conditioning followed by stem-cell rescue. Preclinical studies in animal models of autoimmune disease and observations in patients with rheumatoid arthritis (RA) who were cured after allogeneic bone marrow transplantation for concomitant hematologic malignancy have provided support for the concept.

METHODS

The authors reviewed the results of recent phase I/II studies and data from the EBMT/EULAR Registry on more than 400 patients with autoimmune diseases including RA, systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and juvenile idiopathic arthritis (JIA).

RESULTS

Toxicity resulting from stem-cell grafting depended on underlying disease and the intensity of the conditioning regimen. Treatment-related mortality was low in RA (1.4%) but relatively high (>10%) in patients with JIA, SLE, and SSc, possibly related to visceral involvement in these patients. With the application of uniform and strict criteria, safety has improved. Long-term remissions up to 4 years have been observed in SSc and JIA, while relatively more relapses have occurred in patients with SLE and RA. Sensitivity to antirheumatic drugs was restored in RA and SLE patients, however, resulting in improved disease control.

CONCLUSIONS

Intense immunosuppression and SCT may be an effective therapy for selected patients with severe rheumatic autoimmune disease. Its merits need to be proven via multicenter phase III studies by comparing efficacy and safety with conventional therapy.

SLE - hematopoietic stem cell transplantation for systemic lupus erythematosus

Hematopoietic stem cell transplantation was first reported for patients with systemic lupus erythematosus in 1997. The procedure has since been performed worldwide including in Europe, in Brazil, and in China. A National Institutes of Health-funded phase III clinical trial of hematopoietic stem cell transplantation for refractory systemic lupus erythematosus is anticipated to begin in 2003. Encouraging responses are raising new hope about the role of adult hematopoietic stem cells in systemic lupus erythematosus.

A pilot randomized trial comparing CD34-selected versus unmanipulated hemopoietic stem cell transplantation for severe, refractory rheumatoid arthritis

OBJECTIVE

Evidence from animal studies, case reports, and phase I studies suggests that hemopoietic stem cell transplantation (HSCT) can be effective in the treatment of rheumatoid arthritis (RA). It is unclear, however, if depletion of T cells in the stem cell product infused after high-dose chemotherapy is beneficial in prolonging responses by reducing the number of infused autoreactive T cells. This pilot multicenter, randomized trial was undertaken to obtain feasibility data on whether CD34 selection (as a form of T cell depletion) of an autologous stem cell graft is of benefit in the HSCT procedure in patients with severe, refractory RA.

METHODS

Thirty-three patients with severe RA who had been treated unsuccessfully with methotrexate and at least 1 other disease-modifying agent were enrolled in the trial. The patients received high-dose immunosuppressive treatment with 200 mg/kg cyclophosphamide followed by an infusion of autologous stem cells that were CD34 selected or unmanipulated. Safety, efficacy (based on American College of Rheumatology [ACR] response criteria), and time to recurrence of disease were assessed on a monthly basis for up to 12 months.

RESULTS

All patients were living at the end of the study, with no major unexpected toxicities. Overall, on an intent-to-treat basis, ACR 20% response (ACR20) was achieved in 70% of the patients. An ACR70 response was attained in 27.7% of the 18 patients who had received CD34-selected cells and 53.3% of the 15 who had received unmanipulated cells (P = 0.20). The median time to disease recurrence was 147 days in the CD34-selected cell group and 201 days in the unmanipulated cell group (P = 0.28). There was no relationship between CD4 lymphopenia and response, but 72% of rheumatoid factor (RF)-positive patients had an increase in RF titer prior to recurrence of disease.

CONCLUSION

HSCT can be performed safely in patients with RA, and initial results indicate significant responses in patients with severe, treatment-resistant disease. Similar outcomes were observed in patients undergoing HSCT with unmanipulated cells and those receiving CD34-selected cells. Larger studies are needed to confirm these findings.

High dose chemotherapy and autologous hematopoietic stem cell transplantation for rheumatoid arthritis: a review

A new treatment approach, involving intense immunosuppression and autologous hematopoietic stem cell transplantation (SCT), has emerged in recent years for the treatment of severe, refractory rheumatic autoimmune diseases including rheumatoid arthritis (RA). The rationale of this strategy is based on the concept of immunoablation by intense immunosuppression with subsequent regeneration of naïve T lymphocytes derived from reinfused hematopoietic progenitor cells. Patients with a therapy-refractory, progressively erosive disease who are at risk of functional disability and early mortality are considered eligible for treatment with autologous SCT. The goal is long-term improvement of disease activity and quality of life. However, when offering SCT to RA patients these benefits should be balanced against toxicities and treatment-related mortality. In several patients with intractable RA, long-term remissions were observed with this strategy, but failures have been reported as well. Only small numbers of RA patients have been treated thus far. Although different treatment protocols have been used, high dose chemotherapy as a means to achieve immunoablation has been invariably used in all studies. In this review we discuss background, clinical results, protocols, and future prospects of high dose chemotherapy and autologous SCT for RA.

Induction of tolerance in autoimmune diseases by hematopoietic stem cell transplantation: getting closer to a cure?

Hematopoietic stem cells (HSCs) are the earliest cells of the immune system, giving rise to B and T lymphocytes, monocytes, tissue macrophages, and dendritic cells. In animal models, adoptive transfer of HSCs, depending on circumstances, may cause, prevent, or cure autoimmune diseases. Clinical trials have reported early remission of otherwise refractory autoimmune disorders after either autologous or allogeneic hematopoietic stem cell transplantation (HSCT). By percentage of transplantations performed, autoimmune diseases are the most rapidly expanding indication for stem cell transplantation. Although numerous editorials or commentaries have been previously published, no prior review has focused on the immunology of transplantation tolerance or development of phase 3 autoimmune HSCT trials. Results from current trials suggest that mobilization of HSCs, conditioning regimen, eligibility and exclusion criteria, toxicity, outcome, source of stem cells, and posttransplantation follow-up need to be disease specific. HSCT-induced remission of an autoimmune disease allows for a prospective analysis of events involved in immune tolerance not available in cross-sectional studies.

Factors affecting purification of CD34(+) peripheral blood stem cells using the Baxter Isolex 300i

A total of 201 patients with breast cancer, ovarian cancer, or hematological malignancies underwent mobilization of peripheral blood stem cells (PBSC) using chemotherapy and granulocyte-colony stimulating factor (G-CSF). Stem cell products were collected using the Baxter CS3000 pheresis machine. The Baxter Isolex 300i was used to perform 240 CD34(+) cell separations on the apheresis products. Factors affecting yield and purity of the CD34(+) cells were analyzed. Overall yield was 55% and overall purity was 91.7%. T cell contamination was limited to 0.43% of total cells. Variables including red blood cells (RBC) concentration, platelet concentration, CD34(+) cell concentration, total WBCs selected, and time until processing had little effect on yields and purities. Installation of version 2.5 of the software in the Isolex 300i showed a modest improvement in yield and purity. Patients were reinfused with the cryopreserved CD34(+) selected cells following high-dose chemotherapy. No infusion-related side effects were noted. Analysis of engraftment data using the CD34(+)-selected cells revealed an increased risk of delayed or failed platelet engraftment when <5.0 x 10(6) CD34(+) cells per kilogram were transplanted. The Baxter Isolex 300i provides reproducible CD34(+) cell purification over a wide range of starting conditions. To provide prompt engraftment, >5.0 x 10(6) CD34(+) cells per kilogram should be infused for transplantation.

Stem cell transplantation for autoimmune disease: progress and problems

The current status of stem cell transplantation in rheumatoid arthritis, juvenile chronic arthritis, systemic lupus erythematosus, and systemic sclerosis are reviewed. From a large European bone marrow transplant registry, a birds' eye view of stem cell transplantation for autoimmune disease can be obtained. Among 43 rheumatoid arthritis patients, 35 juvenile chronic arthritis patients, 34 systemic lupus erythematosus patients, and 58 systemic sclerosis patients who underwent stem cell transplantation, initial responses in most patients were good to excellent. Although initial transplant related mortality was low for rheumatoid arthritis, somewhat higher rates for juvenile chronic arthritis, systemic lupus erythematosus, and systemic sclerosis may be falling with modifications in the stem cell transplantation regimens. In rheumatoid arthritis and systemic lupus erythematosus treatment, the criteria for patient selection are still not clear and the therapeutic regimens for stem cell transplantation (and whether follow-up treatment is necessary) are not fully defined. In juvenile chronic arthritis, responses are encouraging although little fully published data beyond that from the European Bone Marrow Transplant Registry exist. In systemic sclerosis, criteria for patient selection and a limited number of stem cell transplantation regimens have been agreed on and controlled trials are underway.

Bone marrow progenitor cell reserve and function and stromal cell function are defective in rheumatoid arthritis: evidence for a tumor necrosis factor alpha-mediated effect

Based on previous reports for impaired hematopoiesis in rheumatoid arthritis (RA), and in view of the current interest in exploring the role of autologous stem cell transplantation (ASCT) as an alternative treatment in patients with resistant disease, we have evaluated bone marrow (BM) progenitor cell reserve and function and stromal cell function in 26 patients with active RA. BM progenitor cells were assessed using flow cytometry and clonogenic assays in short-term and long-term BM cultures (LTBMCs). BM stroma function was assessed by evaluating the capacity of preformed irradiated LTBMC stromal layers to support the growth of normal CD34(+) cells. We found that RA patients exhibited low number and increased apoptosis of CD34(+) cells, defective clonogenic potential of BM mononuclear and purified CD34(+) cells, and low progenitor cell recovery in LTBMCs, compared with healthy controls (n = 37). Patient LTBMC stromal layers failed to support normal hematopoiesis and produced abnormally high amounts of tumor necrosis factor alpha (TNF alpha). TNF alpha levels in LTBMC supernatants inversely correlated with the proportion of CD34(+) cells and the number of colony-forming cells, and positively with the percentage of apoptotic CD34(+) cells. Significant restoration of the disturbed hematopoiesis was obtained following anti-TNF alpha treatment in 12 patients studied. We concluded that BM progenitor cell reserve and function and BM stromal cell function are defective in RA probably due, at least in part, to a TNF alpha-mediated effect. The role of these abnormalities on stem cell harvesting and engraftment in RA patients undergoing ASCT remains to be clarified.

Stem cell transplantation for autoimmune diseases

Much progress has been made in the field of haemopoietic stem cell transplants (HSCTs) for severe autoimmune disorders. Theoretical considerations, animal data and anecdotal evidence suggested some time ago that intensive immunoablation followed by autologous HSCT could restore normal immune reactivity in patients with severe autoimmune disorders. Based on a concept statement issued in 1995, two European societies, the European League Against Rheumatism (EULAR) and the European Group for Blood and Marrow Transplantation (EBMT) began collecting phase I/II trial data in an international collaborative network. Sufficient information from more than 350 patients allows a preliminary assessment with level three evidence. Autologous HSCTs can induce remissions in all disease categories tested so far. Remissions can be transient or durable. HSCTs are associated with significant morbidity and mortality. Treatment-related mortality (TRM) is near 10% at 1 year and is associated with the intensity of the conditioning and the stage of the disease at the time of transplant. Marked interdisease differences exist. There are few data available in haematological autoimmune diseases, more in systemic sclerosis (SSc), systemic lupus erythematosus (SLE), juvenile idiopathic arthritis (JIA) and multiple sclerosis (MS). Patient selection has been recognized as a crucial element from the phase I-II trials. Patients with advanced disease, severely compromised organ function or irreversible organ damage should not be considered as candidates for HSCT. Prospective randomized studies should now determine the value of HSCT compared to standard therapy. Such trials are ongoing for patients with systemic sclerosis (ASTIS trial--Autologous Stem Cell Transplantation International Scleroderma Trial) or are planned for patients with multiple sclerosis (ASTIMS trial--Autologous Stem Cell Transplantation International Multiple Sclerosis Trial) and rheumatoid arthritis (ASTIRA trial--Autologous Stem Cell Transplantation International Rheumatoid Arthritis Trial). More phase II data are needed for other indications such as SLE and JIA.

Collection of hematopoietic stem cells from patients with autoimmune diseases

We reviewed data from 24 transplant centers in Asia, Australia, Europe, and North America to determine the outcomes of stem cell collection including methods used, cell yields, effects on disease activity, and complications in patients with autoimmune diseases. Twenty-one unprimed bone marrow harvests and 174 peripheral blood stem cell mobilizations were performed on 187 patients. Disease indications were multiple sclerosis (76 patients), rheumatoid arthritis (37 patients), scleroderma (26 patients), systemic lupus erythematosus (19 patients), juvenile chronic arthritis (13 patients), idiopathic autoimmune thrombocytopenia (8 patients), Behcet's disease (3 patients), undifferentiated vasculitis (3 patients), polychondritis (1 patient) and polymyositis (1 patient). Bone marrow harvests were used in the Peoples Republic of China and preferred worldwide for children. PBSC mobilization was the preferred technique for adult stem cell collection in America, Australia, and Europe. Methods of PBSC mobilization included G-CSF (5, 10, or 16 microg/kg/day) or cyclophosphamide (2 or 4 g/m2) with either G-CSF (5 or 10 microg/kg/day) or GM-CSF (5 microg/kg/day). Bone marrow harvests were without complications and did not affect disease activity. A combination of cyclophosphamide and G-CSF was more likely to ameliorate disease activity than G-CSF alone (P < 0.001). g-csf alone was more likely to cause disease exacerbation than the combination of cyclophosphamide and g-csf (P = 0.003). Three patients died as a result of cyclophosphamide-based stem cell collection (2.6% of patients mobilized with cyclophosphamide). When corrected for patient weight and apheresis volume, progenitor cell yields tended to vary by underlying disease, prior medication history and mobilization regimen. Trends in the approaches to, and results of, progenitor cell mobilization are suggested by this survey. While cytokine-based mobilization appears less toxic, it is more likely to result in disease reactivation. Optimization with regard to cell yields and safety are likely to be disease-specific and prospective disease-specific studies of mobilization procedures appear warranted.

High-dose chemotherapy and autologous hematopoietic stem cell transplantation in patients with rheumatoid arthritis: results of an open study to assess feasibility, safety, and efficacy

OBJECTIVE

To assess the feasibility, safety, and efficacy of high-dose chemotherapy and autologous hematopoietic stem cell transplantation (HSCT) in patients with severe, refractory rheumatoid arthritis (RA).

METHODS

Fourteen patients (3 male, 11 female, mean age 43 years, mean disease duration 10 years) with active, destructive, refractory RA entered the study. Autologous hematopoietic stem cells were collected by leukapheresis after mobilization with a single infusion of cyclophosphamide (CYC; 4 gm/m2) and subcutaneous injections of filgrastim (granulocyte colony-stimulating factor). Immunomagnetic selection of CD34+ cells from the leukapheresis products was performed to deplete potentially autoreactive lymphocytes. The conditioning regimen consisted of intravenous administration of high doses of CYC (cumulative dose 200 mg/kg), with subsequent reinfusion of the graft. Patients were monitored for disease activity, disability, adverse effects, and hematopoietic and immunologic reconstitution.

RESULTS

All 14 patients completed the mobilization and leukapheresis procedures successfully, and 12 proceeded to receive conditioning and transplantation. Engraftment occurred in all of these patients, with rapid hematologic recovery. No major unexpected toxicity was observed. Marked improvement of disease activity was recorded in 8 of 12 patients at >50% of the visits, with a followup ranging from 7 months to 21 months. The clinical responders included 2 patients who had previously failed treatment with tumor necrosis factor (TNF) blocking agents.

CONCLUSION

High-dose chemotherapy followed by autologous HSCT is feasible and safe, and can result in long-term improvement of disease activity in patients whose condition previously did not respond to conventional antirheumatic drugs or TNF blocking agents. The persistence of active disease in some patients may reflect the heterogeneity of the underlying disease process.

Sustained improvement in rheumatoid arthritis following a protocol designed to deplete B lymphocytes

OBJECTIVES

An open study of B-lymphocyte depletion was undertaken in rheumatoid arthritis (RA) patients to test the hypothesis that B lymphocytes may be essential to disease perpetuation.

METHODS

Five patients with refractory RA were treated with a monoclonal anti-CD20 antibody, cyclophosphamide and prednisolone and followed for 12-17 months. Patient 2 received further treatments at 8 and 12 months and patient 4 at 11 months.

RESULTS

At 26 weeks all patients satisfied the American College of Rheumatology ACR50 and patients 1-3 the ACR70 criteria of improvement, without further therapy. Patients 1, 3 and 5 achieved ACR70 at 1 yr and rheumatoid factor (RF) levels fell to normal. In patients 3 and 5, B lymphocytes returned without relapse. Patient 2 relapsed at 28 weeks and patient 4 at 38 weeks, coincident with the return of B lymphocytes in the presence of raised RF levels. Both achieved ACR70 on retreatment. Adverse events were limited to respiratory episodes (two patients) and marginal thrombocytopenia (one patient).

CONCLUSIONS

These findings are consistent with the concept that RA is critically dependent on B lymphocytes and suggest that B-lymphocyte depletion may be a safe and effective therapy.

Bone marrow transplantation in the treatment of systemic sclerosis

Systemic sclerosis (SSc) is an uncommon, progressive, sometimes lethal fibrotic disease whose pathogenesis probably includes immunologic elements, especially early in its course. There is no proven therapy for this disease, although some promising results have been obtained with the use of immunosuppressive drugs such as cyclophosphamide. There exists a subgroup of patients who have rapidly progressive disease or who are not responsive to conventional treatment, and who may benefit from intensive immunosuppression with stem cell rescue (stem cell transplantation). The rationale for bone marrow transplantation (BMT), and, more recently, peripheral blood stem cell transplantation (SCT), has been validated by studies on animal models of autoimmunity. Autologous transplantation has shown encouraging anecdotal results, and it is now being evaluated in phase I/II studies in patients with predictably poor outcome. In this light, reliably identifying patients early in the course of SSc is extremely important in order to establish correct eligibility criteria. For patients unable to tolerate transplant regimens, other approaches may be feasible. In this regard, nonmyeloablative approaches, such as immunosuppression without rescue and mixed chimerism, are also discussed.

Bone Marrow Transplantation for Non-Malignant Disease

This article reviews the experience in hematopoietic stem cell transplantation (HSCT) for non-malignant disease. HSCT has long been applied as treatment of life-threatening congenital immunodeficiency and metabolic diseases. In Section I, Dr. Parkman reviews that experience for severe combined immunodeficiency, Wiscott-Aldrich syndrome, hyper IGM syndrome, Chédiak-Higashi disease and hereditary lymphohistiocytosis. The value of HSCT in genetic metabolic diseases such as osteopetrosis, osteogenesis imperfecta and the storage diseases are reviewed. In Section II, Dr. Walters reviews the experience over the last decade with allogeneic stem cell transplantation in patients with thalassemia major and sickle cell disease. In Section III, Dr. Sullivan reviews the more recent investigations using stem cell transplantation in patients with advanced autoimmune diseases such as systemic sclerosis, systemic lupus erythematosus, multiple sclerosis and juvenile rheumatoid arthritis. The pathogenesis and outcome with conventional care of these patients, the selection criteria and current results for HSCT, and the future directions in clinical research and patient care using this modality are addressed.

Gene-marked autologous hematopoietic stem cell transplantation of autoimmune disease

In phase I (safety) trials, we have demonstrated the feasibility of autologous hematopoietic stem cell transplantation (HSCT) for patients with autoimmune diseases. Although this review comments on results of our phase I trials, the focus is on phase II (efficacy) trials using gene-marked autologous stem cells.

Bone Marrow Transplantation for Non-Malignant Disease

This article reviews the experience in hematopoietic stem cell transplantation (HSCT) for non-malignant disease. HSCT has long been applied as treatment of life-threatening congenital immunodeficiency and metabolic diseases. In Section I, Dr. Parkman reviews that experience for severe combined immunodeficiency, Wiscott-Aldrich syndrome, hyper IGM syndrome, Chédiak-Higashi disease and hereditary lymphohistiocytosis. The value of HSCT in genetic metabolic diseases such as osteopetrosis, osteogenesis imperfecta and the storage diseases are reviewed. In Section II, Dr. Walters reviews the experience over the last decade with allogeneic stem cell transplantation in patients with thalassemia major and sickle cell disease. In Section III, Dr. Sullivan reviews the more recent investigations using stem cell transplantation in patients with advanced autoimmune diseases such as systemic sclerosis, systemic lupus erythematosus, multiple sclerosis and juvenile rheumatoid arthritis. The pathogenesis and outcome with conventional care of these patients, the selection criteria and current results for HSCT, and the future directions in clinical research and patient care using this modality are addressed.