Clinical and MRI outcome after autologous hematopoietic stem cell transplantation in MS

Autologous Hematopoietic Stem-Cell Transplantation in Multiple Sclerosis: A Systematic Review and Meta-Analysis

INTRODUCTION

In 1995, the use of autologous hematopoietic stem-cell transplantation (AHSCT), which was previously used to treat hematological tumors, was introduced for severe autoimmune diseases such as multiple sclerosis (MS). AHSCT has proven its safety over the past few years due to technical advances and careful patient selection in transplant centers. While most studies have reported that AHSCT led to decreased Expanded Disability Status Scale (EDSS) scores, some patients reported increased EDSS scores following the procedure. Given the contradictory results, we aimed to conduct a comprehensive systematic review and meta-analysis to investigate the efficacy and safety of AHSCT.

METHODS

PubMed, Web of Science, and Scopus were searched in March 2022 using a predefined search strategy. We included cohort studies, clinical trials, case-control studies, and case series that investigated the efficacy or safety of AHSCT in patients with MS. PICO in the present study was defined as follows: problem or study population (P): patients with MS; intervention (I): AHSCT; comparison (C): none; outcome (O): efficacy and safety.

RESULTS

After a two-step review process, 50 studies with a total of 4831 patients with MS were included in our study. Our analysis showed a significant decrease in EDSS score after treatment (standardized mean difference [SMD]: -0.48, 95% CI -0.75, -0.22). Moreover, the annualized relapse rate was also significantly reduced after AHSCT compared to the pretreatment period (SMD: -1.58, 95% CI -2.34, -0.78). The pooled estimate of progression-free survival after treatment was 73% (95% CI 69%, 77). Furthermore, 81% of patients with MS who received AHSCT remained relapse-free (95% CI 76%, 86%). Investigating event-free survival, which reflects the absence of any disease-related event, showed a pooled estimate of 63% (95% CI 54%, 73%). Also, the MRI activity-free survival was 89% (95% CI 84%) among included studies with low heterogeneity. New MRI lesions seem to appear in nearly 8% of patients who underwent AHSCT (95% CI 4%, 12%). Our meta-analysis showed that 68% of patients with MS experience no evidence of disease activity (NEDA) after AHSCT (95% CI 59%, 77). The overall survival after transplantation was 94% (95% CI 91%, 96%). In addition, 4% of patients died from transplant-related causes (95% CI 2%, 6%).

CONCLUSION

Current data encourages a broader application of AHSCT for treating patients with MS while still considering proper patient selection and transplant methods. In addition, with increasing knowledge and expertise in the field of stem-cell therapy, AHSCT has become a safer treatment approach for MS.

Stem Cell Therapy in Neuroimmunological Diseases and Its Potential Neuroimmunological Complications

Background: Since the 1990s, transplantations of hematopoietic and mesenchymal stem cells (HSCT and MSCT) and dendritic cell (DCT) have been investigated for the treatment of neurological autoimmune disorders (NADs). With the growing number of transplanted patients, awareness of neuroimmunolgical complications has increased. Therefore, an overview of SCT for the most common NADs and reports of secondary immunity after SCT is provided. Methods: For this narrative review, a literature search of the PubMed database was performed. A total of 86 articles reporting on different SCTs in NADs and 61 articles dealing with immune-mediated neurological complications after SCT were included. For multiple sclerosis (MS), only registered trials and phase I/II or II studies were considered, whereas all available articles on other disorders were included. The different transplantation procedures and efficacy and safety data are presented. Results: In MS patients, beneficial effects of HSCT, MSCT, and DCT with a decrease in disability and stabilization of disease activity have been reported. These effects were also shown in other NADs mainly in case reports. In seven of 132 reported patients with immune-mediated neurological complications, the outcome was fatal. Conclusions: Phase III trials are ongoing for MS, but the role of SCT in other NADs is currently limited to refractory patients due to occasional serious complications.

The current standing of autologous haematopoietic stem cell transplantation for the treatment of multiple sclerosis

Autologous haematopoietic stem cell transplantation (aHSCT) is gaining traction as a valuable treatment option for patients affected by severe multiple sclerosis (MS), particularly the relapsing–remitting form. We describe the current literature in terms of clinical trials, observational and retrospective studies, as well as immune reconstitution following transplantation, with a focus on the conditioning regimens used for transplantation. The evidence base predominantly consists of non-randomised, uncontrolled clinical trials or data from retrospective or observational cohorts, i.e. very few randomised or controlled trials. Most often, intermediate-intensity conditioning regimens are used, with promising results from both myeloablative and lymphoablative strategies, as well as from regimens that are low and high intensity. Efficacy of transplantation, which is likely secondary to immune reconstitution and restored immune tolerance, is, therefore, not clearly dependent on the intensity of the conditioning regimen. However, the conditioning regimen may well influence the immune response to transplantation. Heterogeneity of conditioning regimens among studies hinders synthesis of the articles assessing post-aHSCT immune system changes. Factors associated with better outcomes were lower Kurtzke Expanded Disability Status Scale, relapsing–remitting MS, younger age, and shorter disease duration at baseline, which supports the guidance for patient selection proposed by the European Society for Blood and Marrow Transplantation. Interestingly, promising outcomes were described for patients with secondary progressive MS by some studies, which may be worth taking into account when considering treatment options for patients with active, progressive disease. Of note, a significant proportion of patients develop autoimmune disease following transplantation, with alemtuzumab-containing regimens associated with the highest incidence.

Real-world application of autologous hematopoietic stem cell transplantation in 507 patients with multiple sclerosis

Objective

To investigate the results of real-world application of non-myeloablative autologous HSCT for multiple sclerosis (MS).

Methods

Between July 2003 and October 2019 at a single center (Northwestern University), 414 patients with relapsing remitting MS (RRMS) and 93 patients with newly diagnosed secondary progressive MS (SPMS) underwent non-myeloablative HSCT.

Results

There was one treatment-related death (0.19%) due to hospital-acquired legionella pneumonia, and one patient developed neutropenic bacteremia (Klebsiella pneumonia) without sepsis. Overall 5-year survival was 98.8%. Post HSCT secondary autoimmune diseases (2nd ADs) were idiopathic thrombocytopenia (ITP) and hypo or hyperthyroidism. ITP was highest with alemtuzumab (14%) and 0 to 2.8% for the non-alemtuzumab regimens. After HSCT, 16 patients developed hypothyroidism (3.5%) and 15 developed hyperthyroidism / Grave’s disease (3.3%). Relapse free survival (RFS) at 5 years for RRMS and SPMS was 80.1% and 98.1%, respectively, while progression free survival (PFS) at 4 years for RRMS and SPMS was 95% versus 66%, respectively. For patients with RRMS, the EDSS significantly improved (p < 0.0001) at each follow-up from a pre-HSCT mean of 3.87 to 2.51, 2.50, 2.41, 2.33, and 2.19 at 1, 2, 3, 4, and 5 years, respectively. For SPMS, the EDSS improved significantly only at 1 year but not thereafter. For SPMS, the mean baseline EDSS of 5.09 changed post-HSCT to 4.85 (p = 0.04), 4.88 (p = 0.2), 4.92 (p = .27), 4.72 (p = 0.07), and 4.2 (p = 0.21) at 1, 2, 3, 4, 5 years, respectively.

Conclusion

In patients with RRMS, autologous non-myeloablative HSCT is an effective one-time therapy, while HSCT appears of less benefit for newly diagnosed SPMS.

New autoimmune diseases after autologous hematopoietic stem cell transplantation for multiple sclerosis

Secondary autoimmune diseases (2ndADs), most frequently autoimmune cytopenias (AICs), were first described after allogeneic hematopoietic stem cell transplantation (HSCT) undertaken for malignant and hematological indications, occurred at a prevalence of ~5-6.5%, and were attributed to allogeneic immune imbalances in the context of graft versus host disease, viral infections, and chronic immunosuppression. Subsequently, 2ndADs were reported to complicate roughly 2-14% of autologous HSCTs performed for an autoimmune disease. Alemtuzumab in the conditioning regimen has been identified as a risk for development of 2ndADs after either allogeneic or autologous HSCT and is consistent with the high rates of 2ndADs when using alemtuzumab as monotherapy. Due to the significant consequences but variable incidence, depending on conditioning regimen, of 2ndADs and similarity in known immune reconstitution kinetics after autologous HSCT for autoimmune diseases and after alemtuzumab monotherapy, we propose that an imbalance between B and T lineage regeneration early after HSCT may underlie the pathogenesis of 2ndADs.

Hematopoietic Stem Cell Transplantation for Autoimmune Disease

The introduction of targeted biologic therapies has changed the treatment landscape for autoimmune diseases (ADs) substantially, but although these therapies provide more specificity, they require continuous administration, rarely restore organ function or reverse disability, and are not curative. Over the last 25 years, hematopoietic stem cell transplantation (HSCT) has been increasingly used to treat patients in whom the risk:benefit ratio of HSCT is acceptable. In contrast to chronic suppression of immune function, this intensive one-off procedure aims to provide treatment-free remissions by the reinduction of self-tolerance. The European Society for Blood and Marrow Transplantation (EBMT) Autoimmune Diseases Working Party (ADWP) has been central to development of this approach, with over 3,300 HSCT registrations for ADs. Recent data have improved the evidence base to support autologous HSCT in multiple sclerosis, systemic sclerosis, and Crohn's disease, along with a wide range of rarer disease indications, and autologous HSCT has become an integral part of treatment algorithms in various ADs.

Intensive immunosuppression followed by autologous hematopoietic stem cell transplantation for the treatment of multiple sclerosis

Autologous hematopoietic stem cell transplantation (AHSCT) to treat multiple sclerosis (MS) has mostly been used in devastating cases as the last option to stop further neurological deterioration. However, evidence from several retrospective clinical trials indicates that young, less disabled patients with highly inflammatory active MS are the most likely to benefit from AHSCT, and after moving from high-intensity to nonmyeloablative procedures the tolerability of AHSCT has increased and its associated risk and mortality have declined considerably. Recent meta-analyses and randomized clinical trials show that AHSCT is more effective than currently approved disease-modifying therapies (DMTs), with suppression of disease activity in 70–90% of patients and long-term cessation of disease activity in two-thirds of treated patients. The rationale for AHSCT is to eliminate autoimmunity and achieve immune resetting by intense immunosuppression followed by infusion of autologous hematopoietic stem cells. Similar effects on the immune system have been suggested for cladribine and alemtuzumab treatment and, together with AHSCT, they constitute the induction or immune-reconstitution therapies for MS. Although, further randomized controlled trials of AHSCT for MS are needed, it has become clear that improved patient selection and lower intensity conditioning regimens have reduced AHSCT associated risks and mortality and strengthened the position of AHSCT among other DMTs. Do we have enough experience and scientific support for AHSCT in MS to move from an exclusive treatment for aggressive, treatment-resistant MS and acquire broader indications, similar to other effective DMTs?

Effect of autologous hematopoietic stem cell transplantation on multiple sclerosis and neuromyelitis optica spectrum disorder: a PRISMA-compliant meta-analysis

We should consider both the treatment effects and adverse effects of autologous hematopoietic stem cell transplantation (AHSCT) on multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). Articles exploring the effect and safety of AHSCT in the treatment of MS and NMOSD and published before December 2019 were identified from the following databases (PubMed, Web of Science, Medline, EMBASE, Cochrane and Google Scholar). The study used STATA 13.0 software to compute the efficacy outcomes. Finally, the meta-analysis included 27 studies (including 1626 MS and 31 NMOSD patients). Regarding the effect of AHSCT on MS, the computed PFS was 74%. Subgroup analyses showed that intermediate-intensity regimen caused PFS 73%. Low-intensity regimen resulted in PFS 85%. High-intensity regimen resulted in PFS 58%. Subgroup analyses indicated that relapsing remitting MS (RRMS), primary progressive MS (PPMS) and secondary progressive MS (SPMS) patients showed PFS 81%, 78% and 60%, respectively. Computed transplant-related mortality (TRM) in MS was 1%. Regarding effect of AHSCT on NMOSD, the computed PFS and TRM was 76% and 0%, respectively. In conclusion, the study supported that AHSCT showed long-term effect on MS and NMOSD patients with a high safety. Low- and intermediate-intensity regimens and RRMS patients showed optimal benefit from AHSCT.

Clinical neurorestorative cell therapies: Developmental process, current state and future prospective

Clinical cell therapies (CTs) for neurological diseases and cellular damage have been explored for more than 2 decades. According to the United States Food and Drug Administration, there are 2 types of cell categories for therapy, namely stem cell-derived CT products and mature/functionally differentiated cell-derived CT products. However, regardless of the type of CT used, the majority of reports of clinical CTs from either small sample sizes based on single-center phase 1 or 2 unblinded trials or retrospective clinical studies showed effects on neurological improvement and the ability to either partially or temporarily thwart the deteriorating cellular processes of the neurodegenerative diseases. There have been only a few prospective, multicenter, randomized, double- blind placebo-control clinical trials of CTs so far in this developing novel area that have shown negative results, and more clinical trials are needed. This will expand our knowledge in exploring the type of cells that yield promising results and restore damaged neurological structure and functions of the central nervous system based on higher level evidence-based medical data. In this review, we briefly introduce the developmental process, current state, and future prospective for clinical neurorestorative CT.

Autologous Hematopoietic Cell Transplantation in Multiple Sclerosis: Changing Paradigms in the Era of Novel Agents

Autologous hematopoietic stem cell transplantation (AHSCT) is established as a standard of care for diseases ranging from hematological malignancies to other neoplastic pathologies and severe immunological deficiencies. In April 1995, our group performed the first AHSCT in progressive multiple sclerosis (MS). Since then, a plethora of studies have been published with encouraging but controversial results. Major challenges in the field include appropriate patient selection, improvements in AHSCT procedure, and timing of this treatment modality. Beyond AHSCT, several new intravenous or oral agents have been developed and approved over the last 20 years in MS. The emergence of multiple effective therapies for MS has created a challenging scenario for both treating physicians and patients. Novel cell-based therapies other than AHSCT are also currently investigated in MS patients with promising results. Our review is aimed at summarizing state-of-the-art knowledge on basic principles and results of AHSCT in MS and its role compared to novel agents.

Efficacy and safety of autologous hematopoietic stem-cell transplantation in multiple sclerosis: a systematic review and meta-analysis

BACKGROUND

Autologous hematopoietic stem-cell transplantation (AHSCT) has been utilized as a treatment option for multiple sclerosis (MS) since 1995. However, this procedure has not been widely implemented in clinical practice owing to its mortality risk. Here, we conduct a meta-analysis to evaluate the long-term efficacy and safety of AHSCT in MS treatment, aiming to optimize the benefit/risk ratio of this therapeutic strategy.

METHODS

We searched the PubMed Web site and clinicaltrials.gov databases. The efficacy endpoints were progression-free survival (PFS) and disease activity-free survival. The safety outcomes were transplant-related mortality (TRM) and overall deaths.

RESULTS

Eighteen eligible studies with a total of 732 participants were enrolled. The PFS was 75% (95% CI, 0.69-0.81), and the estimate of disease activity-free survival was 61% with 48-month follow-up. Subgroups analysis showed that low- and intermediate-intensity regimens were associated with higher PFS 80%. Relapsing remitting MS (RRMS) benefited more from AHSCT than other MS subtypes with PFS 85%. Patients with Gd+ lesions at baseline MRI responded better to AHSCT with PFS 77%. The estimate of TRM was 1.34% (95% CI, 0.39-2.30), and the overall mortality was 3.58%. TRM was significantly higher in high-intensity regimen studies (3.13%) and in older studies (1.93%) performed before 2006.

CONCLUSIONS

This meta-analysis provides evidences that AHSCT can induce long-term remissions for MS patients with a high degree of safety. We indicate low- and intermediate-intensity regimens and RRMS patients with the presence of Gd+ lesions at baseline MRI can obtain the optimal benefit/risk ratio from AHSCT.

[Indications and follow-up for autologous hematopoietic stem cell transplantation in multiple sclerosis: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) in association with the Francophone Society of Multiple Sclerosis]

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organized the 8th allogeneic hematopoietic stem cell transplantation clinical practices harmonization workshop series in September 2017 in Lille, France. In this article we give the indications of autologous stem cell transplantation in multiple sclerosis as well as recommendations regarding post-transplant follow-up of patients under the hospice of the SFGM-TC and the Francophone Society of Multiple Sclerosis.

Autologous haematopoietic stem cell transplantation for neurological diseases

Neuroinflammatory diseases such as multiple sclerosis, neuromyelitis optica, chronic inflammatory demyelinating polyneuropathy and myasthenia gravis are leading causes of physical disability in people of working age. In the last decades significant therapeutic advances have been made that can ameliorate the disease course. Nevertheless, many affected will continue to deteriorate despite treatment, and the costs associated with disease-modifying drugs constitute a significant fiscal burden on healthcare in developed countries. Autologous haematopoietic stem cell transplantation is a treatment approach that aims to ameliorate and to terminate disease activity. The erroneous immune system is eradicated using cytotoxic drugs, and with the aid of haematopoietic stem cells a new immune system is rebuilt. As of today, more than 1000 patients with multiple sclerosis have been treated with this procedure. Available data suggest that autologous haematopoietic stem cell transplantation is superior to conventional treatment in terms of efficacy with an acceptable safety profile. A smaller number of patients with other neuroinflammatory conditions have been treated with promising results. Herein, current data on clinical effect and safety of autologous haematopoietic stem cell transplantation for neurological disease are reviewed.

Autologous haematopoietic stem cell transplantation for treatment of multiple sclerosis

Autologous haematopoietic stem cell transplantation (AHSCT) is a multistep procedure that enables destruction of the immune system and its reconstitution from haematopoietic stem cells. Originally developed for the treatment of haematological malignancies, the procedure has been adapted for the treatment of severe immune-mediated disorders. Results from ∼20 years of research make a compelling case for selective use of AHSCT in patients with highly active multiple sclerosis (MS), and for controlled trials. Immunological studies support the notion that AHSCT causes qualitative immune resetting, and have provided insight into the mechanisms that might underlie the powerful treatment effects that last well beyond recovery of immune cell numbers. Indeed, studies have demonstrated that AHSCT can entirely suppress MS disease activity for 4-5 years in 70-80% of patients, a rate that is higher than those achieved with any other therapies for MS. Treatment-related mortality, which was 3.6% in studies before 2005, has decreased to 0.3% in studies since 2005. Current evidence indicates that the patients who are most likely to benefit from and tolerate AHSCT are young, ambulatory and have inflammatory MS activity. Clinical trials are required to rigorously test the efficacy, safety and cost-effectiveness of AHSCT against highly active MS drugs.

Cell Therapy for Multiple Sclerosis

Cell therapy is considered a promising potential treatment for multiple sclerosis, perhaps particularly for the progressive form of the disease for which there are currently no useful treatments. Over the past two decades or more, much progress has been made in understanding the biology of MS and in the experimental development of cell therapy for this disease. Three quite distinct forms of cell therapy are currently being pursued. The first seeks to use stem cells to replace damaged myelin-forming oligodendrocytes within the CNS; the second aims, in effect, to replace the individual's misfunctioning immune system, making use of haematopoietic stem cells; and the third seeks to utilise endogenous stem cell populations by mobilisation with or without in vitro expansion, exploiting their various reparative and neuroprotective properties. In this article we review progress in these three separate areas, summarising the experimental background and clinical progress thus far made.

Hematopoietic stem cell transplantation in autoimmune disorders: From immune-regulatory processes to clinical implications

Autoimmune diseases are characterized by the development of autoreactive T- and B-cells targeting self-antigens, which eventually can result in chronic and persistent organ damage. The autologous hematopoietic stem cell transplantation (AHSCT) opened new avenues in the treatment of patients with severe, treatment-resistant autoimmune diseases. This paper reviews the immune-regulatory mechanisms behind AHSCT, and also summarizes the experiences of clinical practice related to the therapy in organ-specific and systemic autoimmune diseases. It seems that the intricate interplay of various immune competent cells with regulatory capacity control in a synergistic manner the repopulated immune system after AHSCT, which potentially leads to a significant clinical improvement in certain autoimmune diseases. However, the widespread use of AHSCT was intrinsically limited, due to the serious side-effects of conditioning treatment and relatively high treatment-related mortality; moreover, the development of new effective and safe therapeutic approaches and the dawn of biological agents further limited its indications in the last decade. Nevertheless, with an appropriate patient selection and increased experience of transplant centres, the risks can be minimized, and AHSCT remained still a reasonable choice in multiple sclerosis and systemic sclerosis when the conventional therapy failed and further progression of disease is inevitable.

Autologous hematopoietic stem cell transplantation in multiple sclerosis

Objective:

To summarize the evidence on immunoablative therapy followed by autologous hematopoietic stem cell transplantation (aHSCT) to manage severe and treatment-refractory multiple sclerosis (MS).

Methods:

We collected all the published studies of aHSCT in any form of MS from 1995 to 2016, carefully excluding reports that were updated in subsequent studies. Endpoints were transplant-related mortality (TRM), rate of disease progression, and no evidence of disease activity (NEDA) status. A weighted metaregression based on a Poisson model was run, assessing whether there were study-specific characteristics with an effect on TRM and progression.

Results:

Fifteen studies including 764 transplanted patients were pooled in the meta-analysis. The pooled estimate of TRM was 2.1% (95% confidence interval [CI] 1.3%–3.4%). TRM was higher in older studies (p = 0.014) and in studies with a lower proportion of patients with relapsing-remitting MS (RRMS) (p = 0.028). A higher baseline Expanded Disability Status Scale (p = 0.013) was also significantly associated with a higher TRM. Pooled rate of progression was 17.1% at 2 years (95% CI 9.7%–24.5%) and 23.3% (95% CI 16.3%–31.8%) at 5 years. Lower 2-year progression rate was significantly associated with higher proportions of patients with RRMS (p = 0.004). The pooled proportion of NEDA patients at 2 years was 83% (range 70%–92%) and at 5 years was 67% (range 59%–70%).

Conclusions:

The emerging evidence on this therapeutic approach in MS indicates that the largest benefit/risk profile form this therapeutic approach can be obtained in patients with aggressive MS with a relapsing-remitting course and who have not yet accumulated a high level of disability.

Survival, and time to an advanced disease state or progression, of untreated patients with moderately severe multiple sclerosis in a multicenter observational database: relevance for design of a clinical trial for high dose immunosuppressive therapy with autologous hematopoietic stem cell transplantation

Despite prolonged survival, patients with multiple sclerosis (MS) experience considerable morbidity, which adversely impacts quality of life. To assess the risk-benefit of a clinical trial of high dose immunosuppressive therapy with autologous hematopoietic stem cell transplantation for MS, we sought to determine the natural history of the disease in a comparison group of untreated patients. We identified 285 individuals with 2132 combined observation years (median: 5.6 years; 5th to 95th percentile: 1-21 years), with Expanded Disability Status Scale (EDSS) scores of 3.0-5.5 at baseline observation. Disease-related mortality was zero at five years, 5.4% at 10 years, and 22% at 15 years (40 patients contributing to the data point; 95% confidence interval: 4-32%). Risk for progression to advanced disability, defined as an EDSS score of 8, was very low for the subgroup with a baseline EDSS score of 3-3.5; however, for those with a baseline EDSS score of 4-5.5, 3% had advanced disability after two years, 5% after three years, 6% after four years, 12% after five years, and 40% after 10 years. The estimated probability of disease progression, defined as an increase in EDSS score by ≥ 1.0 sustained for at least 180 days, was 5% after one year, 14% after two years, 22% after three years, 38% after five years, 57% after 10 years, and-80% after 20 years of observation. The relevance of these features to the design of the clinical trial is discussed.

Autologous bone marrow transplantation for the treatment of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system and represents one of the leading causes of neurologic disability in young adults. Current treatments for MS have shown limited efficacy in patients with either a progressive or an aggressive disease course. Hematopoietic stem cell transplantation (HSCT) has been proposed to control or even cure refractory cases of MS. Indeed, HSCT is able to temporarily eradicate the autoreactive cells and to reset the aberrant immune response to self-antigens. In the last decade, owing to the growing experience in selecting the most appropriate patients to transplant and the recent advances in chemotherapeutic and support regimens, the transplant-related mortality of autologous HSCT in MS patients dropped down to 1,3 % and the progression-free survival ranges from 47 % to 100 %. Altogether, these data support autologous HSCT as a possible second-line therapy for refractory MS.

Low intensity lympho-ablative regimen followed by autologous hematopoietic stem cell transplantation in severe forms of multiple sclerosis: A MRI-based clinical study

BACKGROUND

Autologous hematopoietic stem cell transplantation (AHSCT) has been successfully used to treat aggressive forms of multiple sclerosis (MS) that are unresponsive to approved therapies. In the last years, in view of the risk of mortality related to the procedure, the utilization of low-intensity conditioning regimens has been considered.

OBJECTIVE

To report magnetic resonance imaging (MRI) and clinical data in a small cohort of patients treated with a low-intensity lympho-ablative regimen, followed by AHSCT.

METHODS

Seven patients affected by relapsing-remitting MS (RRMS) underwent AHSCT, with cyclophosphamide 120 mg/kg in 2 days as the conditioning regimen; and were then followed with serial MRI evaluations until 36 months, with clinical evaluations until 60 months.

RESULTS

The mean number of gadolinium (Gd)-enhancing lesions significantly decreased after treatment, but a complete suppression of inflammatory activity was not obtained. No deaths occurred, but every patient developed adverse events, although not severe. After 5 years of follow-up, two patients remained stable, one patient markedly improved and four patients had a mild progression of the disease. Only one patient experienced a relapse after treatment.

CONCLUSION

A low-intensity conditioning regimen with AHSCT has a profound effect on MRI inflammation and relapses, but is not able to completely abrogate MRI activity and disease progression of aggressive RRMS.

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.

Cognitive change and neuroimaging following immunoablative therapy and hematopoietic stem cell transplantation in multiple sclerosis: A pilot study

BACKGROUND

Individuals with MS undergoing immunoablative therapy and hematopoietic stem cell transplantation (HSCT) show substantial decrease in brain volume over 2.4 months, presumably from chemotoxic effects, although other mechanisms have also been postulated.

OBJECTIVE

We examined whether volume loss was accompanied by a concomitant decrease in cognition. White and gray matter volumes, and the effect of stem cell dosage were considered.

METHODS

Seven individuals with rapidly progressing MS and poor prognosis underwent high dose immunosuppression and autologous HSCT. Neuropsychological testing and MRI scans were performed at baseline, 2 and 24 months post-procedure.

RESULTS

Cognitive impairment was noted at all times in most participants. Median decline of 1.39% in total brain volume was noted 2 months post-HSCT. By 24 months a further decline of 1.65% was noted. At 2 months significant decline was observed for areas of executive functioning. At 24 months almost no significant declines were noted. No significant correlations were found between cognitive decline and change in imaging variables or stem cell dosage.

CONCLUSIONS

Cognition changed in the early period following treatment but with little apparent relationship to volume changes. With temporal distance from the HSCT procedure, cognition returned to baseline levels. With the caution of a very small sample, preliminary results suggest that immunoablation and HSCT may have no lasting deleterious effects on cognition.

Autologous hematopoietic stem cell transplantation as a treatment option for aggressive multiple sclerosis

OPINION STATEMENT

Despite the development of several injectable or oral treatments for relapsing-remitting multiple sclerosis (RRMS), it remains difficult to treat patients with aggressive disease, and many of these continue to develop severe disability. During the last two decades autologous hematopoietic stem cell transplantation (aHSCT) has been explored with the goal to eliminate an aberrant immune system and then re-install a healthy and tolerant one from hematopoietic precursor cells that had been harvested from the patient prior to chemotherapy. Clinical studies have shown that aHSCT is able to completely halt disease activity in the majority of patients with aggressive RRMS. Research on the mechanisms of action supports that aHSCT indeed leads to renewal of a healthy immune system. Below we will summarize important aspects of aHSCT and mention the currently best-examined regimen.

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.

Long-term efficacy of autologous haematopoietic stem cell transplantation in multiple sclerosis at a single institution in China

Autologous haematopoietic stem cell transplantation (AHSCT) is a promising treatment for multiple sclerosis (MS) patients who have not adequately responded to conventional therapies. We retrospectively evaluated the safety and long-term clinical outcome of AHSCT in MS patients in China. Twenty-five patients with various types of MS were treated with AHSCT. Peripheral blood stem cells were derived by leukapheresis after mobilized with granulocyte colony-stimulating factor. Then CD34+ cell selection of the graft was performed and anti-thymocyte globulin was given for T-cell depletion, with the conditioning regimen BEAM adopted and early and late toxicities recorded. Long-term responses were evaluated by the expanded disability status scale (EDSS), progression-free survival and gadolinium-enhanced magnetic resonance imaging scans. 10, 7 and 8 patients experienced neurological improvement, stabilization and progression, respectively. The median EDSS scores observed over 1-year follow-up after transplantation (5.5-7.0) were consistently lower than the baseline (8.0). The progression-free survival rate was 74, 65 and 48% at 3, 6 and 9 years post-transplant. 58% cases (7/12) had active lesions at baseline and all turned to inactive status in the years of follow-up. 25% cases (3/12) experienced progression after transplantation but had no active lesions in MRI over the whole follow-up period. 17% cases (2/12) without active lesions at baseline progressed active lesions in MRI. The major early toxicity resulted in fever and late toxicity caused transplantation-related mortality due to severe pneumonia and varicella-zoster virus hepatitis, respectively. AHSCT is a feasible treatment for severe MS and its long-term efficacy is favorable.

Escalating immunotherapy of multiple sclerosis

Basic disease-modifying treatment for relapsing forms of active multiple sclerosis (MS) is now available in many countries with high prevalence rates, for this chronic inflammatory disease of the central nervous system. Several lines of evidence support early immunomodulatory treatment with either recombinant interferon-beta or glatiramer acetate, and positive results from phase III trials encourage start of treatment even in patients with clinically isolated syndromes (CIS). However, currently available drugs for basic therapy are only partially effective and patients may still encounter relapses or disease progression. As treatment-refractory, clinically active MS can quickly lead to irreversible neurological disability there is an urgent need for effective escalating strategies. Patients with suboptimal treatment response to basic therapy have been treated with combination therapies, cytotoxic drugs (such as mitoxantrone and cyclophosphamide) or autologous hematopoietic stem cell transplantation. Recently, the monoclonal antibody, natalizumab, was added to this armamentarium. None of these strategies have been vigorously evaluated in large randomized, controlled phase III trials with patients who failed basic therapy. Therefore, the decision to escalate immunotherapy is still based on limited evidence. This article will review potential candidates for intensified immunosuppression and call for innovative study designs to better evaluate escalating immunotherapy in MS.

Autologous hematopoietic cell transplantation for multiple sclerosis: a systematic review

BACKGROUND AND OBJECTIVES

The purpose of this systematic review was to evaluate the safety and efficacy of autologous hematopoietic cell transplantation in patients with progressive multiple sclerosis (MS) refractory to conventional medical treatment.

METHODS

Eight case series met our a priori inclusion criteria for the primary outcome of progression-free survival. Individual study quality was rated using an 11-item scale for case series. The strength of the overall body of evidence for each outcome was rated using a system developed by the ECRI Institute. Data from different studies were statistically combined using meta-analysis. An additional six studies were included for a summary of mortality and morbidity.

RESULTS

For secondary progressive MS, immunoablative therapy with autologous bone marrow/peripheral blood stem cell transplantation was associated with higher progression-free survival (up to 3 years following treatment) when using intermediate-intensity conditioning regimens compared with high-intensity conditioning regimens. The evidence was insufficient to determine whether the treatment was effective in patients with other types of MS. Treatment-related mortality was about 2.7%.

CONCLUSIONS

Patients with secondary progressive MS refractory to conventional medical treatment have longer progression-free survival following autologous stem cell transplantation with intermediate-intensity conditioning regimens than with high-intensity conditioning regimens.

Autologous stem cell transplantation in autoimmune and rheumatic diseases: from the molecular background to clinical applications

Autoimmune diseases have a multifactorial origin. Because of disturbances of the immune system, autoreactive T and B cells target self-antigens, leading to permanent organ damage. Despite novel therapeutic protocols, the disease course is chronic and in many instances the outcome is lethal. The efficacy of stem cell therapy has been observed in autoimmune animal models and in autoimmune diseases related to haematological abnormalities. Although the therapy is more than 30 years old, its broad spread has been delayed by the serious side-effects due to the conditioning treatments based on oncological protocols. Evaluation of the data of patients who have undergone autologous stem cell therapy reinforced the view that protocols used for conditioning treatments, mostly causing lymphoablation, and procedures carried out in specialist centres significantly reduced mortality, with an almost optimal therapeutical efficacy. New, multicentre investigations have been launched to compare the efficacy of various protocols. In this review, we summarize certain aspects of the molecular background of autologous stem cell transplantation and also depict the response to therapy in various autoimmune and rheumatic diseases.

Hematopoietic stem cell transplantation in multiple sclerosis

Intensive immunosuppresion followed by hematopoietic stem cell transplantation (HSCT) has been suggested as potential treatment in severe forms of multiple sclerosis (MS). Since 1995 ca. 400 patients have been treated with HSCT. Stabilization or improvement occurred in almost 70% of cases at least for 3 years post-transplant. Magnetic resonance revealed the capacity of autologous HSCT to suppress or markedly reduce gadolinium-enhancing lesions. The progression of brain atrophy declined after two years post-HSCT. The profound immunological changes following autologous HSCT may result in restoration of self-tolerance. Relatively young patients with active inflammatory lesions of relatively short duration and rapidly progressive disease, but still low disability scores, unresponsive to conventional therapy seem the best candidates for transplantation. Transplant-related mortality was 6% in the first EBMT report and 5.3% in the second one. No deaths were reported since 2001. Very high-intensity conditioning regimen is associated with higher risk of toxicity without significant increase in efficacy. The effects of transplantation and transplantation-related morbidity are dependent on patient-selection, time of transplantation and conditioning regimens used.This review is a comprehensive study of the results obtained in several single-center and multicenter studies. Patient characteristics, transplantations steps, toxicity and clinical outcome have been monitored and compared.

Back to the future for multiple sclerosis therapy: focus on current and emerging disease-modifying therapeutic strategies

The last decade has seen numerous advances in the treatment of multiple sclerosis with six immunotherapeutic agents licensed for use. Although these therapeutic agents have powerful effects upon the inflammatory phase of disease, they have limitations in treating the progression of disability and in their safety profile. This review focuses on our current understanding of first- and second-line treatments for multiple sclerosis, including combination therapies, and also discusses the most promising novel therapeutic strategies on the horizon. Such agents include orally administered immunosuppressive drugs, monoclonal antibodies, antigen-specific tolerance, and neural protection and repair strategies. The challenge ahead lies in the delivery of potent drugs to inhibit inflammation and neurodegeneration while limiting side effects. Further elucidation of the pathophysiology of disease may provide new clinical targets and disease-relevant biomarkers that, in combination with proteomics, may help personalize treatment to individual patients.

Relapse of chronic inflammatory demyelinating polyneuropathy 5 years after autologous stem cell transplantation

We describe relapse of chronic inflammatory demyelinating polyneuropathy in a patient who had been in remission for 5 years after treatment with autologous stem cell transplantation. Before the transplant, he needed higher doses of immunosuppressive treatment than are now necessary to maintain his improved condition. He now receives intravenous immunoglobulins at monthly intervals.

Early highly aggressive MS successfully treated by hematopoietic stem cell transplantation

Background

During the last 15 years, high-dose chemotherapy with autologous hematopoietic stem cell transplantation (HSCT) has globally been performed for severe multiple sclerosis (MS). Most patients have been in progressive phase with long disease duration. As a rule, treatment effect has been minor or moderate.

Patients

Since 2004, we have performed HSCT in nine young patients with “malignant” relapsing–remitting MS. Criteria for treatment were short duration of disease; very frequent, severe relapses; recent improvement periods indicating potential for recovery after strong immunosuppression.

Findings

Median age at treatment was 27 (range 9–34) years, MS duration 26 (4–100) months, and annualized relapse rate 10 (4–12). Median Disability Status Scale (extended disability status scale, EDSS) at HSCT was 7.0 (3.5–8.0). Median follow-up time April 2008 is 29 (23–47) months. Median EDSS improvement is 3.5 (1.0–7.0), clearly surpassing most previous reports. One patient relapsed mildly with rapid recovery 7 months after HSCT. All patients are otherwise stable, median EDSS being 2.0 (0–6.0). Before HSCT, 61 relapses occurred in 82 patient months; during follow-up, one relapse in 289 patient months.

Conclusion

This small series of patients with “malignant” relapsing–remitting MS suggests HSCT to be an effective treatment option for this relatively rare disease course. It further suggests that future criteria for HSCT in MS should be close to the present ones.

Autologous haematopoietic stem-cell transplantation in multiple sclerosis

Intense immunosuppression followed by autologous haematopoietic stem-cell transplantation has been assessed over the past few years as a possible new therapeutic strategy in severe forms of multiple sclerosis. Pioneering studies began in 1995, and since then, more than 400 patients worldwide have been treated with this procedure. Small uncontrolled studies show that about 60-70% of treated cases do not progress in the follow-up period of at least 3 years. Transplant-related mortality, which was 5-6% in the first reported series, has reduced in the past 5 years to 1-2%. Relapses dramatically decrease and inflammatory MRI activity is almost completely suppressed. Autologous haematopoietic stem-cell transplantation is associated with qualitative immunological changes in the blood, suggesting that, beyond its immunosuppressive potential, it could also have some beneficial effect for the resetting of the immune system. Patients with severe, rapidly worsening multiple sclerosis who are unresponsive to approved therapies could be candidates for this treatment, but its clinical efficacy has still to be shown in large, prospective, controlled studies.

Autologous and allogeneic hematopoietic stem cell transplantation for Multiple Sclerosis: perspective on mechanisms of action

Multiple Sclerosis (MS) is a frequent demyelinating immune-mediated disease of the central nervous system (CNS) that affects principally young adults and leads to severe physical and cognitive impairment. The current standard treatment makes use of the immune modulators beta-interferon, glatiramer acetate and natalizumab, or immunosuppressants such as mitoxantrone. However, these agents are only partially effective and in a number of patients fail to achieve satisfactory disease control. Autologous hematopoietic stem cell transplantation (HSCT) is being explored in the treatment of severe MS as a means of delivering high-dose immunosuppression followed by 'rescue' of the immuno-hematopoietic system with autologous HSC. The potential therapeutic benefit is based on the concept of so-called 'resetting' the immune system. The use of allogeneic HSCT as a possible therapeutic approach for severe MS is inspired by case reports of MS patients that underwent allogeneic HSCT for a concomitant hematological malignancy, and subsequently is supported by data from rodent models of MS. Allogeneic HSCT may offer specific therapeutic effects, such as the replacement of the autoreactive immune compartment by healthy allogeneic cells and the development of a graft-versus-autoimmunity (GVA) effect. Here, we review the currently available experimental and clinical evidence to support the role of autologous and allogeneic HSCT in MS.

Rituximab in a patient with multiple sclerosis--effect on B cells, plasma cells and intrathecal IgG synthesis

OBJECTIVE

To study the time course of immunoglobulin, B and plasma cells in the blood and cerebrospinal fluid (CSF) before and during rituximab treatment in a patient with severe relapsing-remitting multiple sclerosis (MS) in relation to clinical and MRI findings.

METHODS

Immunoglobulins in the CSF were measured by nephelometry and detected by isoelectrical focussing. CSF and blood cell subtypes from seven time points were analysed by flow cytometry.

RESULTS

Treatment with rituximab induced a dramatic and sustained improvement in clinical and MRI findings over a follow-up period of 20 months. By contrast, the initially completely suppressed B and plasma cells in both the blood and CSF reappeared after 5 and 10 months, CSF cells being the first to reappear. Interestingly, intrathecal IgG synthesis persisted throughout the study period.

DISCUSSION

Although highly effective in this case, the clinical effect in larger series and the mechanism of rituximab in MS deserves further evaluation.

[Immunoablation and autologous hematopoietic stem cell transplantation (AHSCT) in multiple sclerosis]

Numerous pathophysiological arguments supporting immunosuppression for multiple sclerosis have been collected during recent years. The relevance of intense immunosuppression, in terms of clinical benefit and early or late risk, remains a matter of discussion. Immunoablation followed by autologous hematopoietic stem cell transplantation (AHSCT) in multiple sclerosis uses intense immunosuppression, followed by reinjection of AHSC, a rescue procedure for the induced aplasia. This method targets disappearance of the immune disorder, and thus, in theory, the interruption of the disease course. Use of AHSCT to treat several types of autoimmune diseases has been performed with contrasted results. In multiple sclerosis, the experience has been gained over the past 10 years through short series of patients treated at a late stage of their disease. This article highlights the recent data of this particular treatment option in multiple sclerosis as well as the therapeutic aims that should be investigated in further trials.

Intense immunosuppression in patients with rapidly worsening multiple sclerosis: treatment guidelines for the clinician

Several lines of evidence link immunosuppression to inflammation in patients with multiple sclerosis (MS) and provide a rationale for the increasing use of immunosuppressive drugs in the treatment of MS. Treatment-refractory, clinically active MS can quickly lead to devastating and irreversible neurological disability and treating these patients can be a formidable challenge to the clinician. Patients with refractory MS have been treated with intense immunosuppression, such as cyclophosphamide or mitoxantrone, or with autologous haematopoeitic stem cell transplants. Evidence shows that intense immunosuppression might be effective in patients who are unresponsive to immunomodulating therapy, such as interferon beta and glatiramer acetate. Natalizumab, a new addition to the armamentarium for treating MS, might also have a role in the treatment of this MS phenotype. This Review describes the use of intense immunosuppressant drugs and natalizumab in patients with rapidly worsening MS and provides clinicians with guidelines for the use of these drugs in this patient group.

Emerging therapies for multiple sclerosis

This review examines the mode of action, safety profile and clinical efficacy of some of the most promising new therapeutic strategies for multiple sclerosis. Autologous hematopoietic stem cell transplantation can regenerate a new and tolerant immune system and is a potentially effective rescue therapy in a subset of patients with aggressive forms of MS refractory to approved immunomodulatory and immunosuppressive agents. High-dose cyclophosphamide without stem cell support is suggested to induce prolonged remissions through similar immunological mechanisms with less toxicity. Fingolimod (FTY720) is a novel oral immunomodulating agent that acts through preventing lymphocyte recirculation from lymphoid organs. Monoclonal antibody therapy has provided scientists and clinicians the opportunity to rationally direct the therapeutic intervention against specific molecules. Targeting molecules of the immune system such as CD52 (alemtuzumab), CD25 (daclizumab), VLA-4 (natalizumab) and CD20 (rituximab) have resulted in potent immunomodulatory effects through sometimes unpredicted mechanisms. The potential of immunoglobulins to induce remyelination in the CNS is being investigated in an attempt to develop therapies promoting tissue repair and functional recovery. The evidence supporting the potential of these emerging immunotherapies suggests that strong progress is being made in the development of effective cures for multiple sclerosis.

Relapse of chronic inflammatory demyelinating polyneuropathy 5 years after autologous stem cell transplantation

We describe relapse of chronic inflammatory demyelinating polyneuropathy in a patient who had been in remission for 5 years after treatment with autologous stem cell transplantation. Before the transplant, he needed higher doses of immunosuppressive treatment than are now necessary to maintain his improved condition. He now receives intravenous immunoglobulins at monthly intervals.

A three-year study of brain atrophy after autologous hematopoietic stem cell transplantation in rapidly evolving secondary progressive multiple sclerosis

BACKGROUND AND PURPOSE

In multiple sclerosis (MS), autologous hematopoietic stem cell transplantation (AHSCT) induces a profound suppression of clinical activity and MR imaging-detectable inflammation, but it may be associated with a rapid brain volume loss in the months subsequent to treatment. The aim of this study was to assess how AHSCT affects medium-term evolution of brain atrophy in MS.

MATERIALS AND METHODS

MR imaging scans of the brain from 14 patients with rapidly evolving secondary-progressive MS obtained 3 months before and every year after AHSCT for 3 years were analyzed. Baseline normalized brain volumes and longitudinal percentage of brain volume changes (PBVCs) were assessed using the Structural Image Evaluation of Normalized Atrophy software.

RESULTS

The median decrease of brain volume was 1.92% over the first year after AHSCT and then declined to 1.35% at the second year and to 0.69% at the third year. The number of enhancing lesions seen on the pretreatment scans was significantly correlated with the PBVCs between baseline and month 12 (r = -0.62; P = .02); no correlation was found with the PBVCs measured over the second and third years.

CONCLUSIONS

After AHSCT, the rate of brain tissue loss in patients with MS declines dramatically after the first 2 years. The initial rapid development of brain atrophy may be a late consequence of the pretransplant disease activity and/or a transient result of the intense immunoablative conditioning procedure.

Bone marrow transplantation: Does it stop MS progression?

Based upon the theory that MS is an acquired autoimmune disease and not purely genetically defined, complete ablation of the defective immune system and replacement with a naive non-disease-causing system de novo from stem cells autologously-obtained should lead to a long-lasting remission of disease. The rationale and methodology are discussed along with recommendations for patient selection. Results of several small studies are presented along with some preliminary results from the ongoing Canadian effort.

Allogeneic bone marrow transplantation in models of experimental autoimmune encephalomyelitis: evidence for a graft-versus-autoimmunity effect

Autologous hematopoietic stem cell transplantation (HSCT) is being explored in the treatment of severe multiple sclerosis (MS), and is based on the concept of "resetting" the immune system. The use of allogeneic HSCT may offer additional advantages, such as the replacement of the autoreactive immune compartment by healthy allogeneic cells and development of a graft-versus-autoimmunity (GVA) effect. However, in clinical practice, the genetic susceptibility to MS of allogeneic stem cell donors is generally unknown, and GVA may therefore be an important mechanism of action. Experimental autoimmune encephalomyelitis (EAE)-susceptible and -resistant mouse strains were used to determine the roles of genetic susceptibility, level of donor-chimerism, and alloreactivity in the therapeutic potential of syngeneic versus allogeneic bone marrow transplant (BMT) for EAE. After transplantation and EAE induction, animals were evaluated for clinical EAE and ex vivo myelin oligodendrocyte glycoprotein-specific proliferation. Early after BMT, both syngeneic and allogeneic chimeras were protected from EAE development. On the longer term, allogeneic but not syngeneic BMT conferred protection, but this required high-level donor-chimerism from EAE-resistant donors. Importantly, when EAE-susceptible donors were used, robust protection from EAE was obtained when active alloreactivity, induced by donor lymphocyte infusions, was provided. Our findings indicate the requirement of a sufficient level of donor-chimerism from a nonsusceptible donor in the therapeutic effect of allogeneic BMT. Importantly, the data indicate that, independently of genetic susceptibility, active alloreactivity is associated with a GVA effect, thereby providing new evidence to support the potential role of allogeneic BMT in the treatment of MS.

Autologous stem cell transplantation for progressive multiple sclerosis: update of the European Group for Blood and Marrow Transplantation autoimmune diseases working party database

Over the last decade, hematopoietic stem cells transplantation (HSCT) has been increasingly used in the treatment of severe progressive autoimmune diseases. We report a retrospective survey of 183 multiple sclerosis (MS) patients, recorded in the database of the European Blood and Marrow Transplantation Group (EBMT). Transplant data were available from 178 patients who received an autologous graft. Overall, transplant related mortality (TRM) was 5.3% and was restricted to the period 1995-2000, with no further TRM reported since then. Busulphan-based regimens were significantly associated with TRM. Clinical status at the time of transplant and transplant techniques showed some correlations with toxicity. No toxic deaths were reported among the 53 patients treated with the BEAM (carmustine, etoposide, cytosine-arabinoside, melphalan)/antithymocyte globulin (ATG) regimen without graft manipulation, irrespective of their clinical condition at the time of the transplant. Improvement or stabilization of neurological conditions occurred in 63% of patients at a median follow-up of 41.7 months, and was not associated with the intensity of the conditioning regimen. In this large series, HSCT was shown as a promising procedure to slow down progression in a subset of patients affected by severe, progressive MS; the safety and feasibility of the procedure can be significantly improved by appropriate patient selection and choice of transplant regimen.