Stem cell transplantation for autoimmune diseases

Immunomodulatory Mechanism and Potential Application of Dental Pulp-Derived Stem Cells in Immune-Mediated Diseases

Dental pulp stem cells (DPSCs) are mesenchymal stem cells (MSCs) derived from dental pulp tissue, which have high self-renewal ability and multi-lineage differentiation potential. With the discovery of the immunoregulatory ability of stem cells, DPSCs have attracted much attention because they have similar or even better immunomodulatory effects than MSCs from other sources. DPSCs and their exosomes can exert an immunomodulatory ability by acting on target immune cells to regulate cytokines. DPSCs can also migrate to the lesion site to differentiate into target cells to repair the injured tissue, and play an important role in tissue regeneration. The aim of this review is to summarize the molecular mechanism and target cells of the immunomodulatory effects of DPSCs, and the latest advances in preclinical research in the treatment of various immune-mediated diseases, providing new reflections for their clinical application. DPSCs may be a promising source of stem cells for the treatment of immune-mediated diseases.

Efficacy and safety of autologous haematopoietic stem cell transplantation in systemic sclerosis: a systematic review of the literature

We aimed to assess the efficacy of autologous haematopoietic stem cell transplantation (HSCT) for skin sclerosis (SSc) and lung function in SSc. We performed a systematic literature review in the PubMed and Scopus databases from the earliest records to March 2016. We assessed study quality using the Cochrane tool for randomized studies, the Newcastle-Ottawa Scale for controlled cohort studies and an 18-item quality-appraisal checklist for case series. The primary outcome was the improvement of skin thickening using the modified Rodnan Skin Score (mRSS). The secondary outcome was efficacy on lung function, using diffusing capacity of the lungs for carbon monoxide and forced vital capacity (FVC). The safety of the procedure was evaluated. The literature search identified 431 citations. There were 38 studies involving a total of 344 patients who fulfilled our inclusion criteria. No meta-analysis was performed due to a high heterogeneity. There was a significant improvement in mRSS in the majority of the reports (P < 0·05), and the results were sustained for up to 8 years after autologous HSCT. The randomized studies and the four cohort studies each showed a slight but statistically significant improvement in FVC at 1 or 2 years. The treatment-related mortality calculated by pooling patients of 35 studies (336 patients with a follow-up up to 146 months) was 8·3% after autologous HSCT and 1% in cyclophosphamide-treated groups. Despite heterogeneity among the studies, we determined that autologous HSCT significantly improved cutaneous fibrosis and slightly improved FVC. Safety of autologous HSCT is acceptable given the severity of the disease. This systematic review was registered on PROSPERO, number CRD42016027951.

The impact of P2X7 receptor antagonist, brilliant blue G on graft-versus-host disease in mice after allogeneic hematopoietic stem cell transplantation

The purpose of this study was to investigate the role of P2X7 on liver inflammation in mice after HSCT. Hematopoietic stem cells obtained from C57BL/6 mice were administrated into BALB/c mice to establish GVHD model. On day 7, 14, 21 and 28 after HSCT, mice received P2X7R antagonist brilliant blue G (BBG) or not were sacrificed for analysis of weight loss, liver inflammation, cytokine secretion, P2X7, NLRP3 expression as well as caspase-1 activation. Liver inflammation with neutrophils and macrophases infiltration as well as weight loss increase was present after HSCT, but improved after administration with high dose of BBG compared with lower dose. High dose of P2X7R inhibitor administration after HSCT previously reduced levels of IL-1β, IL-18, caspase-1, NLRP3 as well as P2X7, and the level of alanine transaminase (ALT) and the ratio of aspartate amino transferase (AST)/ALT compared with that receiving low dose of BBG. Meanwhile, P2X7R blockage also reduced infiltration of macrophages and neutrophils and levels of CXCL8 and CCL2 in peripheral blood as well as improved liver function. In conclusion, blockage of P2X7R by BBG exerts a protective effect on GVHD post HSCT and improves liver function suggesting that this receptor could be considered as an attractive target for treatment of GVHD.

Myelodysplastic syndrome and associated coagulopathy: a case report and review

Myelodysplastic syndrome (MDS) is a primary bone marrow disorder whose hallmark is the development of peripheral cytopenias and a predilection toward the development of acute myeloid leukemia (AML). Patients often have hypercellular bone marrows with dysplastic features that may involve multiple lineages. An increased awareness of MDS has led to the reporting of a number of associated autoimmune and paraneoplastic conditions in the medical literature. We present the case of an elderly man who was transferred to our institution with persistent, refractory bleeding several weeks after the resection of a sebaceous cyst. Despite reoperation, treatment with topical and intravenous hemostatic agents, and transfusion of blood products, the patient's bleeding persisted. A comprehensive evaluation for the cause of his coagulopathy was undertaken. Bone marrow evaluation was consistent with MDS. A paraneoplastic consumptive coagulopathy or fibrinolytic process in conjunction with MDS-related platelet dysfunction was felt to be the most likely etiology of the patient's bleeding.

Therapy with stem cells in inflammatory bowel disease

Inflammatory bowel disease (IBD) affects a part of the young population and has a strong impact upon quality of life. The underlying etiology is not known, and the existing treatments are not curative. Furthermore, a significant percentage of patients are refractory to therapy. In recent years there have been great advances in our knowledge of stem cells and their therapeutic applications. In this context, autologous hematopoietic stem cell transplantation (HSCT) has been used in application to severe refractory Crohn’s disease (CD), with encouraging results. Allogenic HSCT would correct the genetic defects of the immune system, but is currently not accepted for the treatment of IBD because of its considerable risks. Mesenchymal stem cells (MSCs) have immune regulatory and regenerative properties, and low immunogenicity (both autologous and allogenic MSCs). Based on these properties, MSCs have been used via the systemic route in IBD with promising results, though it is still too soon to draw firm conclusions. Their local administration in perianal CD is the field where most progress has been made in recent years, with encouraging results. The next few years will be decisive for defining the role of such therapy in the management of IBD.

Hematopoietic stem cell transplantation for pediatric autoimmune disease: where we stand and where we need to go

In children, autoimmune diseases and their therapies cause significant morbidity, especially in those with severe or refractory disease. The constant development of new immunosuppressants and targeted biological therapies leads to a unique 'moving target' with regard to the gold standard of treatment for these patients. However, incidental findings of cure after hematopoietic stem cell transplant (HSCT) in patients with concomitant benign or malignant hematologic disorders and autoimmune disease raise the question of whether HSCT can be used as upfront therapy for patients with severe autoimmune diseases. Animal data have been helpful in investigating both the efficacy of this modality and the mechanisms underlying cure. The potential for a therapeutic 'graft vs autoimmunity' (GVA) effect with an allogeneic approach highlights the already acknowledged need for clinical trials of allogeneic vs autologous transplant in these diseases where an autologous transplant would be the 'intuitive' albeit potentially erroneous choice. We critically review the data generated in the field thus far, and emphasize the need for an organized, interdisciplinary approach to conduct prospective clinical trials to answer these and other questions and advance the field.

Autologous hematopoietic stem cell transplantation for autoimmune diseases

Ten years have passed since the first published consensus statement on the use of hematopoietic stem cell transplantation (HSCT) in the treatment of severe autoimmune disease (AD) appeared. During that time, around 700 patients suffering from severe AD have undergone HSCT in the frame of phase I/II clinical trials from over 20 countries including the US. The majority have received an autologous HSCT using one of a limited number of regimens, consistent with the original consensus statement. Long-term drug-free remissions, remission then relapse, no response and treatment-related mortality (TRM) were seen in all the subgroups of AD. An overall TRM of 7% was observed, with marked variation between ADs, i.e. 11% in systemic lupus erythematosus (SLE) and only 1 patient in rheumatoid arthritis (RA). Phase III prospective, comparative randomized trials are running or being planned in multiple sclerosis (MS), systemic sclerosis (SSc), SLE and RA. Basic science programs are also being undertaken to study the immunological mechanisms underlying the clinical events observed.

Autologous hematopoietic stem cell transplantation for autoimmune diseases

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

Progress in hematopoietic stem cell transplantation for autoimmune diseases

An international co-ordinated Phase I/II program commenced 8 years ago to study the role of profound immunoablation with hematopoietic stem cell transplantation in the treatment of severe, refractory autoimmune disease. Almost 700 patients have been treated for a variety of autoimmune diseases, mostly multiple sclerosis, systemic sclerosis, also referred to as scleroderma, systemic lupus erythematosis, rheumatoid arthritis and juvenile idiopathic arthritis. An overall treatment-related mortality of 7% was observed, with significant differences between diseases; 11% in systemic lupus erythematosis and only one patient with rheumatoid arthritis. Although outcomes are disparate in different diseases, there were significant durable, clinically useful remissions, relapses, and nonresponders in all groups. Although different protocols were employed, a clear advantage from the more intensive myeloablative regimens was not observed, although an increased toxicity did occur. The Phase I/II data was exploited in designing the Phase III randomized, comparative trials that are running in systemic sclerosis, multiple sclerosis and rheumatoid arthritis in Europe, and at the advanced planning stage in systemic sclerosis, multiple sclerosis and systemic lupus erythematosis in the USA. In parallel, a basic science program is proceeding with the prospective studies to improve understanding of the mechanisms of autoimmune disease activity and remission.

Haematopoietic stem cell transplantation for the treatment of systemic sclerosis and other autoimmune disorders

Systemic sclerosis (SSc) with involvement of vital organs has up to 50% 5-year mortality and no treatment is known which changes the natural history. Although components of vascular, immunological and fibrotic processes are involved, drugs such as cyclophosphamide (CY), an alkylating agent and a potent immunosuppressive, have been partially effective in uncontrolled studies. The dose of such agents is limited by the inevitable toxicity on the bone marrow, but this threshold may be superseded by first removing the patient's own haematopoietic stem cells, followed by reconstitution of the marrow after high-dose myeloablative CY or other therapy. This autologous haematopoietic stem cell transplantation (HSCT) technique has been applied to approximately 650 patients with severe autoimmune diseases worldwide, > 100 of whom had SSc. Of these, 75 are included in the Basle registry. Around 70% of patients responded with a significant (> 25%) improvement of the thickened skin and stabilisation of vital organ involvement. Approximately a third achieved a durable remission. The treatment-related mortality was 8.5%. Based on these encouraging Phase I/II study results, several multi-centre, international, prospective randomised Phase III trials are running or being planned. The preliminary data suggest that through such a jolt of heavy immunosuppression, the dysregulated autoaggressive immune system may be re-regulated. It is hypothesised that this results in fewer autoinflammatory and unwanted stimulatory signals to other systems such as vascular endothelium and fibroblasts, and these mechanisms are currently under study.

Stem cell transplantation for autoimmune disorders. Coincidental autoimmune disease in patients transplanted for conventional indications

The practice of stem cell transplantation for severe autoimmune diseases refractory to conventional therapy originated from two landmark discoveries: the excellent results of animal experiments, and serendipitous observations in human coincidental diseases. The latter include patients with an often long-standing autoimmune disease who have developed a haematological condition (aplasia, leukaemia, lymphoma) requiring stem cell transplantation (from marrow as well as from blood). Allogeneic and autologous transplants have been performed. The initial information deriving from both procedures is their feasibility, even more convincing since the patients were affected by two simultaneous severe diseases. The information derived from autologous transplants has, however, now been superseded by the considerable and increasing number of those transplants performed for primary autoimmune diseases. On the other hand, allogeneic stem cell transplantation for very severe autoimmune diseases is being cautiously explored in current protocols. Allogeneic transplants in coincidental disease have also suggested a graft-versus-autoimmunity effect, which may become relevant in conjunction with non-myeloablative, less toxic condition regimens.

Disappearance of diffuse calcinosis following autologous stem cell transplantation in a child with autoimmune disease

A 12-year-old girl presented with arthritis, myalgia, anemia and positive ANA. Subsequently, she developed recurrent episodes of pulmonary hemorrhage, thrombocytopenia, CNS abnormalities, skin ulcers and diffuse calcinosis. This was followed by secondary antiphospholipid syndrome. Despite vigorous immunosuppression, the patient became bedridden. A peripheral blood stem cell autograft was offered when she developed pulmonary hypertension and digital ischemia at the age of 16 years. The post-transplantation course was uneventful. Liquefaction of calcinosis nodules with improvement of mobility occurred gradually. She is now 24 months post-transplant with no sign of disease activity and total disappearance of calcinosis nodules.

Pulmonary complications of solid organ and hematopoietic stem cell transplantation

The ability to successfully transplant solid organs and hematopoietic stem cells represents one of the landmark medical achievements of the twentieth century. Solid organ transplantation has emerged as the standard of care for select patients with severe vital organ dysfunction and hematopoietic stem cell transplantation has become an important treatment option for patients with a wide spectrum of nonmalignant and malignant hematologic disorders, genetic disorders, and solid tumors. Although advances in surgical techniques, immunosuppressive management, and prophylaxis and treatment of infectious diseases have made long-term survival an achievable goal, transplant recipients remain at high risk for developing a myriad of serious and often life-threatening complications. Paramount among these are pulmonary complications, which arise as a consequence of the immunosuppressed status of the recipient as well as from such factors as the initial surgical insult of organ transplantation, the chemotherapy and radiation conditioning regimens that precede hematopoietic stem cell transplantation, and alloimmune mechanisms mediating host-versus-graft and graft-versus-host responses. As the population of transplant recipients continues to grow and as their care progressively shifts from the university hospital to the community setting, knowledge of the pulmonary complications of transplantation is increasingly germane to the contemporary practice of pulmonary medicine.

Novel Approaches to Therapy for SLE

Systemic lupus erythematosus (SLE) is an autoimmune disease manifested by multi-organ involvement and elevated titers of anti-DNA antibodies. Current therapies for SLE are broadspectrum, and include steroids and immunosuppressive cytotoxic agents that are counterbalanced by the toxicity and side effects of the medications. One of the goals is to target therapies by altering specific known mechanisms of inflammation and autoimmunity. Although the inciting antigen is still unknown in SLE, it may be possible to alter the regulation of the immune response by targeted molecular therapy. Methods under investigation, which may be beneficial, are manipulation of second-signal stimulation of the immune response (anti-CD40L), manipulation of cytokines (monoclonal anti-IL-10), inducing tolerance by administration of blocking peptides (LJP394), and the manipulation of idiotypes (IVIg). In this article, we also discuss modalities that are steroid-sparing (MTX), and selective immunosuppression (stem-cell restoration and MMF). We review the ongoing literature from 2000-2002, utilizing the MEDLINE search. Controlled trials, open trials, and trials in phase I and II have been included, and anecdotal reports were excluded. The major advances have been with mycophenolate mofetil (MMF) and LJP 394.

The promise of hematopoietic stem cell transplantation for autoimmune diseases

Hematopoietic stem cell transplantation (HSCT) is being increasingly utilized for the treatment of a whole spectrum of severe autoimmune diseases refractory to conventional therapy. Although allogeneic HSCT has been followed by durable complete remission in a restricted number of patients with coincidental disease, the autologous procedure is generally preferred because of its lesser toxicity. Most autoimmune diseases are the consequence of a multistep process, mainly originating from the interplay of genetic, environmental, and hormonal factors. It has been postulated that if immunosuppressive regimens can eliminate or effectively reduce the level of autoreactive T and B cells, then regeneration of de novo immunity even in the autologous setting may bypass the initial breakdown of self-tolerance and ensure prolonged disease remission. As mentioned in a recent review of this field, protocol design including conditioning regimen, patient selection, stem cell source and final outcome are likely to be disease-specific. The following is a summary of the 2002 International Bone Marrow Transplantation Registry/American Society of Blood and Bone Marrow Transplantation (IBMTR/ASBMT) satellite symposium in Orlando, Florida on 24 February 2002 on 'Expanding the Promise of Hematopoietic Stem Cell Transplantation in Autoimmune Diseases'.

Isolation and therapeutic potential of human haemopoietic stem cells

The haemopoietic stem cell (HSC) has long been regarded as an archetypal, tissue specific, stem cell, capable of completely regenerating haemopoiesis after myeloablation. It has proved relatively easy to harvest HSC, from bone marrow or peripheral blood. In turn, isolation of these cells has allowed therapeutic stem cell transplantation protocols to be developed, that capitalise on their prodigious self renewal and proliferative capabilities. Ex vivo approaches have been described to isolate, genetically manipulateand expand pluripotent stem cell subsets. These techniques have been crucial to the development of gene therapy, and may allow adults to enjoy the potential advantages of cord blood transplantation. Recently, huge conceptual changes have occurred in stem cell biology. In particular, the dogma that, in adults, stem cells are exclusively tissue restricted has been questioned and there is great excitement surrounding the potential plasticity of these cells, with the profound implications that this has, for developing novel cellular therapies. Mesenchymal stem cells, multipotent adult progenitor cells and embryonic stem cells are potential sources of cells for transplantation purposes. These cells may be directed toproduce HSC, in vitro and in the future may be used for therapeutic, or drug development, purposes.

Refractory Evans' syndrome treated with allogeneic SCT followed by DLI. Demonstration of a graft-versus-autoimmunity effect

Evans' syndrome, a combination of autoimmune haemolytic anaemia and autoimmune (idiopathic) thrombocytopenic purpura, is generally harder to treat and more refractory than the single entities. In a male patient with refractory disease, predominantly thrombocytopenic, an allogeneic reduced intensity BMT from his human leukocyte antigen (HLA)-identical sister was followed by a dramatic platelet peak while he was still experiencing initial engraftment (presumably of autologous origin), but subsequently by progressive relapse associated with mixed chimerism. Five gradually incremental DLI achieved complete donor chimerism, which was associated not only with grade II graft-versus-host disease (GVHD), but also with complete clinical and biological remission for 2 years post-transplant. Long-term FU is necessary before claiming that allogeneic stem cell transplantation (SCT) is capable of curing an autoimmune blood disease. However, there is evidence for a graft-versus-autoimmunity effect in this case.