Haematopoietic stem cell transplantation for autoimmune disorders: the American perspective

Multiple sclerosis and cancer: when two wrongs make a right?

INTRODUCTION

Current treatments for multiple sclerosis (MS) remain partially successful, with certain patients remaining treatment resistant. A recent treatment, known as 'immunoablation' has been used in severe cases of adult MS with promising results. However, due to its high risk and reservation for severe or refractory cases, its full potential remains unknown.

METHODS

We report the case of MM, a 14-year-old boy diagnosed with MS and a concurrent diagnosis of Hodgkin's lymphoma.

RESULTS

After receiving aggressive chemotherapy (immunoablation) for Hodgkin's lymphoma, MM's MS symptoms appear to have remitted, and he has remained progression- and disease activity-free for over six years.

DISCUSSION

This case study will focus on MM's cognitive and behavioural development over this time, but will also discuss treatment implications raised by this rare case.

Current therapeutic leads for the treatment of autoimmune diseases: stem cell transplantation and inhibition of post-translational modifications of autoantigens

BACKGROUND

The complexity of autoimmune diseases is reflected on their clinicopathological heterogeneity and the failure to find treatments that cure them after over a century of research. Conventional treatments help ameliorate disease activity but they treat the symptoms whereas the diseases remain incurable in the vast majority of patients.

OBJECTIVE

To confront diseases of such nature it is essential to discover therapeutics that will lead to the induction of tolerance or the specific deletion of autoreactive lymphocytes. Current basic and clinical research strategies focus on the better identification of self-antigens, the induction of T regulatory cells that can suppress autoreactive cell activities or, more radically, the 'reformatting' of the immune system through hematopoietic stem cell transplantation (HSCT).

METHODS

We analyzed literature on autoimmune disease therapeutics, focusing on new antigens that may arise from post-translational modifications of common proteins and, also, the area of HSCT.

RESULTS/CONCLUSIONS

With the recent discovery that citrullination of self-epitopes may be a major pathogenic mechanism for, at least, certain types of autoimmune diseases, it becomes apparent that potentially any self-antigen in the body can be a target of an autoimmune attack. In addition, although the available data on HSCT applied to patients suffering from severe refractory autoimmune diseases do not allow for the determination of the efficacy of the various methods employed to re-educate the immune system, they contribute to our understanding of disease pathogenesis and the improvement on the therapeutic approaches.

Haematopoietic SCT in severe autoimmune diseases: updated guidelines of the European Group for Blood and Marrow Transplantation

In 1997, the first consensus guidelines for haematopoietic SCT (HSCT) in autoimmune diseases (ADs) were published, while an international coordinated clinical programme was launched. These guidelines provided broad principles for the field over the following decade and were accompanied by comprehensive data collection in the European Group for Blood and Marrow Transplantation (EBMT) AD Registry. Subsequently, retrospective analyses and prospective phase I/II studies generated evidence to support the feasibility, safety and efficacy of HSCT in several types of severe, treatment-resistant ADs, which became the basis for larger-scale phase II and III studies. In parallel, there has also been an era of immense progress in biological therapy in ADs. The aim of this document is to provide revised and updated guidelines for both the current application and future development of HSCT in ADs in relation to the benefits, risks and health economic considerations of other modern treatments. Patient safety considerations are central to guidance on patient selection and HSCT procedural aspects within appropriately experienced and Joint Accreditation Committee of International Society for Cellular Therapy and EBMT accredited centres. A need for prospective interventional and non-interventional studies, where feasible, along with systematic data reporting, in accordance with EBMT policies and procedures, is emphasized.

Autologous hematopoietic stem cell transplantation in autoimmune diseases

The term 'autoimmune diseases' encompasses a spectrum of diseases whose clinical manifestations and, possibly, biological features vary widely. The results of conventional treatment are considered unsatisfactory in aggressive forms, with subsets of patients having short life expectancies. Relying on wide experimental evidence and more feeble clinical data, some research groups have used autologous hematopoietic stem cell transplantation (HSCT) in the most disabling autoimmune diseases with the aim of resetting the patient's immune system. Immunoablative conditioning regimens are preferred over their myeloablative counterparts, and some form of in vivo and/or ex vivo T-cell depletion is generally adopted. Despite 15 years' experience, published controlled clinical trials are still lacking, with the evidence so far available coming from pilot studies and registry surveys. In multiple sclerosis, clinical improvement, or at least lasting disease stabilization, can be achieved in the majority of the patients; nevertheless, the worst results are observed in patients with progressive disease, where no benefit can be expected from conventional therapy. Concerning rheumatologic diseases, wide experience has been acquired in systemic sclerosis, with long-term improvements in cutaneous disease being frequently reported, although visceral involvement remains unchanged at best. Autografting has proved to be barely effective in rheumatoid arthritis and quite toxic in juvenile idiopathic arthritis, whereas it leads to clinical remission and the reversal of visceral impairment in the majority of patients with systemic lupus erythematosus. A promising indication is Crohn's disease, in which long-term endoscopic remission is frequently observed. Growing experience with autologous HCST in autoimmune diseases has progressively reduced concerns about transplant-related mortality and secondary myelodysplasia/leukemia. Therefore, a sustained complete remission seems to be within the reach of autografting in some autoimmune diseases; in others, the indications, risks and benefits of autografting need to be better defined. Consequently, the search for new drugs should also be encouraged.

Mobilization, harvesting and selection of peripheral blood stem cells in patients with autoimmune diseases undergoing autologous hematopoietic stem cell transplantation

Peripheral blood stem cells (PBSC) were mobilized in 130 patients with autoimmune diseases undergoing autologous hematopoietic stem cell transplantation using cyclophosphamide 2 g/m(2) and either granulocyte colony-stimulating factor (G-CSF) 5 mcg/kg/day (for systemic lupus erythematosus (SLE) and secondary progressive multiple sclerosis, SPMS) or G-CSF 10 mcg/kg/day (for relapsing remitting multiple sclerosis (RRMS), Crohn's disease (CD), systemic sclerosis (SSc), and other immune-mediated disorders). Mobilization-related mortality was 0.8% (one of 130) secondary to infection. Circulating peripheral blood (PB) CD34(+) cells/microl differed significantly by disease. Collected CD34(+) cells/kg/apheresis and overall collection efficiency was significantly better using Spectra apheresis device compared to the Fenwall CS3000 instrument. Patients with SLE and RRMS achieved the lowest and the highest CD34(+) cell yields, respectively. Ex vivo CD34(+) cell selection employing Isolex 300iv2.5 apparatus was significantly more efficient compared to CEPRATE CS device. Circulating PB CD34(+) cells/microl correlated positively with initial CD34(+) cells/kg/apheresis and enriched product CD34(+) cells/kg. Mean WBC and platelet engraftment (ANC>0.5 x 10(9)/l and platelet count >20 x 10(9)/l) occurred on days 9 and 11, respectively. Infused CD34(+) cell/kg dose showed significant direct correlation with faster white blood cell (WBC) and platelet engraftment. When adjusted for CD34(+) cell/kg dose, patients treated with a myeloablative regimen had significantly slower WBC and platelet recovery compared to non-myeloablative regimens.

Successful unrelated cord blood transplantation in a 7-year-old boy with Evans syndrome refractory to immunosuppression and double autologous stem cell transplantation

Evans syndrome is an autoimmunopathy characterized by thrombocytopenia and autoimmune hemolytic anemia with poor response to immunosuppression. A 2-yr-old boy with Evans syndrome showed only short-lasting responses to immunosuppressive treatment including double autologous peripheral stem cell transplantation (SCT). Intracranial bleeding required emergency splenectomy and external ventricular drainage. Unrelated umbilical cord blood was given following conditioning with busulfan, thiotepa, etoposide and antithymocyte globulin. One year after SCT the patient shows stable blood counts without immunosuppression. This is the first child reported with Evans syndrome successfully treated by means of unrelated cord blood transplantation.

Hematopoietic stem cell transplantation (HSCT): An approach to autoimmunity

HSCT provides the opportunity to replace a damaged tissue. It is the most important treatment for high risk hematologic malignant and non malignant disorders. An important challenge in the identification of matched donors/patients is the HLA diversity. The Mexican Bone Marrow Registry (DONORMO) has nowadays > 5000 donors. The prevalent alleles are Amerindian, Mediterranean (Semitic and Spanish genes) and African. In theory, it is possible to find 11% of 6/6 A-B-DR low resolution matches for 70% of patients with Mexican ancestry. We contributed with 39 unrelated, cord blood and autologous HSCT for patients with malignant, genetic and autoimmune disorders. Overall disease survival was 50% (2-7 years) depending on the initial diagnosis, conditioning, disease evolution or other factors. Clinical studies using autologous and unrelated HSC are performed on patients with refractory autoimmune diseases producing mixed results: mainly, T1D, RA, MS, SLE. Improvement has been observed in skin damage and quality of life in SLE and systemic sclerosis. Disease stabilization in 2/3 of MS patients. However, in RA and T1D, initial benefits have been followed by eventual relapse. With growing clinical experience and protocol improvement, treatment-related mortality is decreasing. Proof efficacy will be achieved by comparing HSCT with standard therapy in autoimmunity.

Chronic graft versus host disease of oral mucosa: Review of available therapies

The use of hematopoetic stem cell transplantation (HSCT) has greatly expanded in the recent years for many neoplastic and hematological disorders. Chronic graft versus host disease (cGVHD) is a major complication of allogeneic HSCT and a major cause of morbidity and mortality. Oral mucosal involvement is frequent in cGVHD and contributes significantly to the overall burden of the condition. Oral medicine professionals should be familiar with various treatment options for oral cGVHD. This review discusses treatment modalities available for the management of oral mucosal manifestations of cGVHD. Available evidence for efficacy and safety of various systemic and topical agents, including corticosteroids, calcineurin antagonists, mycophenolate mofetil, and extracorporeal photopheresis, is reviewed.

High-dose cyclophosphamide without stem cell rescue for refractory multifocal motor neuropathy

Patients with multifocal motor neuropathy (MMN) respond to intravenous immune globulin (IVIg) and cyclophosphamide, although the benefit is not sustained. High-dose cyclophosphamide can induce a remission in patients with autoimmune diseases, including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We describe a patient with refractory MMN who improved with high-dose cyclophosphamide (50 mg/kg for 4 days) without stem cell rescue. Following treatment she discontinued IVIg. At a 6-month examination, her strength had improved and she had regained the ability to write. High-dose cyclophosphamide may be a successful treatment for patients with MMN refractory to other therapies.

Treatment of severe autoimmune disease by stem-cell transplantation

Transplantation of haematopoietic stem cells--cells capable of self renewing and reconstituting all types of blood cell--can treat numerous lethal diseases, including leukaemias and lymphomas. It may now be applicable for the treatment of severe autoimmune diseases, such as therapy-resistant rheumatoid arthritis and multiple sclerosis. Studies in animal models show that the transfer of haematopoietic stem cells can reverse autoimmunity, and several mechanistic pathways may explain this phenomenon. The outcome of ongoing clinical trials, as well as of studies in patients and animal models, will help to determine the role that stem-cell transplantation can play in the treatment of autoimmune diseases.

High-dose therapy for autoimmune neurologic diseases

PURPOSE OF REVIEW

Autoimmune neurologic diseases are being increasingly recognized, and treated with conventional immunosuppressive agents. Patients with 'refractory' conditions have been treated with high-dose therapy, with or without autologous stem cell transplants. This paper reviews the rationale, methods, and recent results of high-dose therapy and the questions that it raises.

RECENT FINDINGS

High-dose therapy has been used in progressive multiple sclerosis and in myasthenia gravis and autoimmune neuropathies that are refractory to conventional immunotherapy. A variety of methods of immune ablation have been used; most require hematopoietic 'rescue' with stem cell transplantation. High-dose cyclophosphamide alone is immunoablative but not myeloablative, permitting the patient's endogenous stem cells to repopulate the hematopoietic/immune systems. The results have been highly encouraging in many but not all cases, with durable responses in the limited time they have been followed up. The treatments carry some risks and have been reserved for refractory cases until now.

SUMMARY

High-dose therapy, without or with stem cell transplantation, is a valuable resource for the treatment of patients with refractory autoimmune neurologic diseases. It is important to define the diseases and patient characteristics likely to lead to benefit, to optimize the methods of treatment and to establish when in the patient's course to administer it. High-dose therapy may eventually become the standard for treatment of severe progressive autoimmune neurologic disorders.

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.