High-dose immune suppression and autologous hematopoietic stem cell transplantation in refractory Crohn disease

From the updated landscape of the emerging biologics for IBDs treatment to the new delivery systems

Inflammatory bowel diseases (IBDs) treatments have shifted from small-molecular therapeutics to the oncoming biologics. The first-line biologics against the moderate-to-severe IBDs are mainly involved in antibodies against integrins, cytokines and cell adhesion molecules. Besides, other biologics including growth factors, antioxidative enzyme, anti-inflammatory peptides, nucleic acids, stem cells and probiotics have also been explored at preclinical or clinical studies. Biologics with variety of origins have their unique potentials in attenuating immune inflammation or gut mucosa healing. Great advances in use of biologics for IBDs treatments have been archived in recent years. But delivering issues for biologic have also been confronted due to their liable nature. In this review, we will focus on biologics for IBDs treatments in the recent publications; summarize the current landscapes of biologics and their promise to control disease progress. Alternatively, the confronted challenges for delivering biologics will also be analyzed. To combat these drawbacks, some new delivering strategies are provided: firstly, designing the functional materials with high affinity toward biologics; secondly, the delivering vehicle systems to encapsulate the liable biologics; thirdly, the topical adhering delivery systems as enema. To our knowledge, this review is the first study to summarize the updated usage of the oncoming biologics for IBDs, their confronted challenges in term of delivery and the potential combating strategies.

Hematopoietic Stem Cell Transplantation in Refractory Crohn's Disease: Should It Be Considered?

Hematopoietic stem cell transplantation (HSCT) is widely used in benign and malignant hematological diseases. During the last decade, HSCT, mainly autologous, also gained increasing attention in the treatment of refractory autoimmune diseases. Crohn's disease (CD) is an inflammatory bowel disease leading to transmural inflammation potentially affecting all parts of the luminal gastrointestinal tract. Despite improving therapeutic options, including various biologics, some patients are refractory to all lines of available conservative therapy, leading to increased morbidity and reduced quality of life. Apart from surgery, HSCT might be a reasonable treatment alternative for refractory CD patients. This review aims to describe the current role of HSCT in CD and discusses the procedure, the correct patient selection, the clinical efficacy from initial remission to following relapse rates, and complications of this treatment.

Stem cell transplantation for induction of remission in medically refractory Crohn's disease

BACKGROUND

Crohn's disease (CD) is an inflammatory bowel disease that causes inflammation and stricture, of any part of the mucosa and the gut wall. It forms skip lesions, sparing the areas in between the affected parts of the gastrointestinal tract. Crohn's disease could have one of three complications; fistula, intestinal obstruction due to stricture, or gastrointestinal inflammation presenting as severe diarrhoea. Stem cell therapy (SCT) is an innovative treatment that has been recently used in CD. The exact role of SCT in CD is still unclear. Stem cells modify the immunity of the patients or act as a "reset tool" for the immune system as in the case of systemically-injected stem cells, or regenerate the affected area of necrotic and inflammatory tissue as in the case of local injection into the lesion. Stem cells are a wide variety of cells including pluripotent stem cells or differentiated stem cells. The hazards range from rejection to symptomatic manifestations as fever or increase infection.  OBJECTIVES: The objective of this Cochrane systematic review is to assess the effects of stem cell transplantation compared to standard of care alone or with placebo on efficacy and safety outcomes in patients with refractory CD.

SEARCH METHODS

We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and clinical trial registries (Clinicaltrials.gov, World Health Organization-International Clinical Trials Registry Platform WHO ICTRP) from inception to 19 March 2021, without any language, publication year, or publication status restrictions. In addition, we searched references of included studies and review articles for further references. An update of the published studies was done during the writing of the review.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) that assessed the effectiveness and safety of SCT in refractory CD versus standard care alone (control) or with placebo.

DATA COLLECTION AND ANALYSIS

Two review authors (SEN and SFA) independently screened the studies retrieved from the search results for inclusion, extracted data and assessed the risk of bias. Any disagreement was resolved through a consensus between the authors. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We conducted our search on 19 March 2021 and identified 639 records. We added two records by a manual search of the published reviews on the topic to a total of 641 records. The Covidence program removed 125 duplicates making a total of 516 reports. Two review authors (SEN and SFA) screened titles and abstracts and excluded 451 records with the remaining 65 for full-text records screened independently by the two authors; only 18 studies were considered for inclusion.  We included seven RCTs with a total of 442 participants for the meta-analysis. The intervention group included 234 patients, and the control group included 208 patients. Nine trials are ongoing and, two abstracts are awaiting classification. All patients in the control and intervention groups received the standard therapy for CD. Only three studies used blinding methods for the control group in the form of a placebo, with one study of the three stated that the blinding method was inefficient. The patients and personnel were aware of the intervention in the rest of the four studies as they were open-label trials. However, the effect of unblinding was balanced by the low risk of detection bias in five of the included studies. The evidence is uncertain about the effect of SCT on achieving clinical remission as compared to control/placebo (risk ratio (RR) 1.88, 95% Confidence Interval (CI) 0.80 to 4.41; 3 studies; low-certainty evidence). The evidence is very uncertain about the effect of SCT on achieving Crohn's Disease Activity Index (CDAI) <150 at 24 weeks compared to control (RR1.02 95% CI 0.67 to 1.56; 4 studies; very-low certainty evidence). SCT is likely to achieve fistula closure as compared to the control/placebo both in the short term (RR 1.48, 95% CI 1.12 to 1.96); low-certainty evidence) and in the long term (RR 1.42, 95% CI 1.09 to 1.87; 4 studies; low-certainty evidence) follow-up. The evidence is very uncertain about the effect of SCT to cause no difference in the number of total adverse events as compared to the control/placebo (RR 0.99, 95% CI [0.88 to  1.13); 4 studies; very-low-certainty evidence). However, SCT is likely to increase the number of serious adverse events as compared to the control/placebo (RR 1.22, 95% CI 0.88 to 1.67; 7 studies; low-certainty evidence). The evidence is very uncertain about the effect of SCT to decrease the withdrawal due to adverse events as compared to the control/placebo (RR 0.78, 95% CI 0.32 to 1.89; 3 studies; very-low certainty evidence). Funding by pharmaceutical companies was found in three studies, with one including more than 50% of our studied population.

AUTHORS' CONCLUSIONS

SCT shows an uncertain effect on clinical remission with low certainty of evidence. SCT shows an uncertain effect on CDAI score to reach <150 after 24 weeks of treatment, with very low certainty evidence. SCT shows beneficial effects on fistula-closure during short and long-term follow-up with low-certainty evidence in both outcomes. There was no change in the total number of adverse events with SCT as compared to control, with very low certainty evidence. While there was a moderate effect on increasing the number of serious adverse events in the SCT group, as compared to the control with low-certainty evidence. Withdrawal due to adverse events was slightly higher in the control group with very low certainty evidence. All the participants were refractory to standard medical treatment, but the number of participants was small, this may limit the generalizability of the results. Further research is needed for validation. More objective outcomes are needed in the assessment of stem cell effectiveness in the treatment of Crohn's disease, especially the intestinal CD subtype; with standardization of the dose, methods of stem cell preparation, route of administration, and inclusion criteria to the studies to achieve clear results.

Pharmacologically Enhanced Regulatory Hematopoietic Stem Cells Revert Experimental Autoimmune Diabetes and Mitigate Other Autoimmune Disorders

Type 1 diabetes (T1D) is characterized by the loss of immune self-tolerance, resulting in an aberrant immune responses against self-tissue. A few therapeutics have been partially successful in reverting or slowing down T1D progression in patients, and the infusion of autologous hematopoietic stem cells (HSCs) is emerging as an option to be explored. In this study, we proposed to pharmacologically enhance by ex vivo modulation with small molecules the immunoregulatory and trafficking properties of HSCs to provide a safer and more efficacious treatment option for patients with T1D and other autoimmune disorders. A high-throughput targeted RNA sequencing screening strategy was used to identify a combination of small molecules (16,16-dimethyl PGE₂ and dexamethasone), which significantly upregulate key genes involved in trafficking (e.g., CXCR4) and immunoregulation (e.g., programmed death ligand 1). The pharmacologically enhanced, ex vivo-modulated HSCs (regulatory HSCs [HSC.Regs]) have strong trafficking properties to sites of inflammation in a mouse model of T1D, reverted autoimmune diabetes in NOD mice, and delayed experimental multiple sclerosis and rheumatoid arthritis in preclinical models. Mechanistically, HSC.Regs reduced lymphocytic infiltration of pancreatic β cells and inhibited the activity of autoreactive T cells. Moreover, when tested in clinically relevant in vitro autoimmune assays, HSC.Regs abrogated the autoimmune response. Ex vivo pharmacological modulation enhances the immunoregulatory and trafficking properties of HSCs, thus generating HSC.Regs, which mitigated autoimmune diabetes and other autoimmune disorders.

Treatment of Inflammatory Bowel Disease: A Comprehensive Review

Inflammatory bowel disease (IBD), as a global disease, has attracted much research interest. Constant research has led to a better understanding of the disease condition and further promoted its management. We here reviewed the conventional and the novel drugs and therapies, as well as the potential ones, which have shown promise in preclinical studies and are likely to be effective future therapies. The conventional treatments aim at controlling symptoms through pharmacotherapy, including aminosalicylates, corticosteroids, immunomodulators, and biologics, with other general measures and/or surgical resection if necessary. However, a considerable fraction of patients do not respond to available treatments or lose response, which calls for new therapeutic strategies. Diverse therapeutic options are emerging, involving small molecules, apheresis therapy, improved intestinal microecology, cell therapy, and exosome therapy. In addition, patient education partly upgrades the efficacy of IBD treatment. Recent advances in the management of IBD have led to a paradigm shift in the treatment goals, from targeting symptom-free daily life to shooting for mucosal healing. In this review, the latest progress in IBD treatment is summarized to understand the advantages, pitfalls, and research prospects of different drugs and therapies and to provide a basis for the clinical decision and further research of IBD.

A review of hematopoietic stem cell transplantation for autoimmune diseases: multiple sclerosis, systemic sclerosis and Crohn's disease. Position paper of the Brazilian Society of Bone Marrow Transplantation

Autoimmune diseases are an important field for the development of bone marrow transplantation, or hematopoietic stem cell transplantation. In Europe alone, almost 3000 procedures have been registered so far. The Brazilian Society for Bone Marrow Transplantation (Sociedade Brasileira de Transplantes de Medula Óssea) organized consensus meetings for the Autoimmune Diseases Group, to review the available literature on hematopoietic stem cell transplantation for autoimmune diseases, aiming to gather data that support the procedure for these patients. Three autoimmune diseases for which there are evidence-based indications for hematopoietic stem cell transplantation are multiple sclerosis, systemic sclerosis and Crohn's disease. The professional stem cell transplant societies in America, Europe and Brazil (Sociedade Brasileira de Transplantes de Medula Óssea) currently consider hematopoietic stem cell transplantation as a therapeutic modality for these three autoimmune diseases. This article reviews the evidence available.

Medical, ethical, and legal aspects of hematopoietic stem cell transplantation for Crohn’s disease in Brazil

Crohn's disease (CD) is a chronic inflammatory bowel disease that can affect any part of the gastrointestinal tract. The etiology of CD is unknown; however, genetic, epigenetic, environmental, and lifestyle factors could play an essential role in the onset and establishment of the disease. CD results from immune dysregulation due to loss of the healthy symbiotic relationship between host and intestinal flora and or its antigens. It affects both sexes equally with a male to female ratio of 1.0, and its onset can occur at any age, but the diagnosis is most commonly observed in the range of 20 to 40 years of age. CD diminishes quality of life, interferes with social activities, traumatizes due to the stigma of incontinence, fistulae, strictures, and colostomies, and in severe cases, affects survival when compared to the general population. Symptoms fluctuate between periods of remission and activity in which complications such as fistulas, strictures, and the need for bowel resection, surgery, and colostomy implantation make up the most severe aspects of the disease. CD can be progressive and the complications recurrent despite treatment with anti-inflammatory drugs, corticosteroids, immunosuppressants, and biological agents. However, over time many patients become refractory without treatment alternatives, and in this scenario, hematopoietic stem cell transplantation (HSCT) has emerged as a potential treatment option. The rationale for the use of HSCT for CD is anchored in animal studies and human clinical trials where HSCT could reset a patient's immune system by eliminating disease-causing effector cells and upon immune recovery increase regulatory and suppressive immune cells. Autologous HSCT using a non-myeloablative regimen of cyclophosphamide and anti-thymocyte globulin without CD34+ selection has been to date the most common transplant conditioning regimen adopted. In this review we will address the current situation regarding CD treatment with HSCT and emphasize the medical, ethical, and legal aspects that permeate the procedure in Brazil.

CELL THERAPY IN INFLAMMATORY BOWEL DISEASE

In recent years, cell-based therapies have been explored in various immune-mediated inflammatory diseases, including inflammatory bowel disease (IBD). Cell therapy is the process of introducing new cells into an organism or tissue in order to treat a disease. The most studied cellular treatment in IBD was "stem cells-based therapy", which was explored according to different protocols in terms of type of donors, stem cells sources, study design and clinical endpoints. More recently, preliminary studies have also described the clinical use of "regulatory cells", which include T-reg and Tr1 cells, and "tolerogenic" dendritic cells. Finally, induced pluripotent stem cells are the subject of an intensive preclinical research program on animal models, including those related to colitis.

Development of Colonic Organoids Containing Enteric Nerves or Blood Vessels from Human Embryonic Stem Cells

The increased interest in organoid research in recent years has contributed to an improved understanding of diseases that are currently untreatable. Various organoids, including kidney, brain, retina, liver, and spinal cord, have been successfully developed and serve as potential sources for regenerative medicine studies. However, the application of organoids has been limited by their lack of tissue components such as nerve and blood vessels that are essential to organ physiology. In this study, we used three-dimensional co-culture methods to develop colonic organoids that contained enteric nerves and blood vessels. The development of enteric nerves and blood vessels was confirmed phenotypically and genetically by the use of immunofluorescent staining and Western blotting. Colonic organoids that contain essential tissue components could serve as a useful model for the study of colon diseases and help to overcome current bottlenecks in colon disease research.

Organoid-based regenerative medicine for inflammatory bowel disease

Inflammatory bowel disease (IBD) consists of two major idiopathic gastrointestinal diseases: ulcerative colitis and Crohn's disease. Although a significant advance has been achieved in the treatment of IBD, there remains a particular population of patients that are refractory to the conventional treatments, including the biologic agents. Studies have revealed the importance of "mucosal healing" in improving the prognosis of those difficult-to-treat patients, which indicates the proper and complete regeneration of the damaged intestinal tissue. In this regard, organoid-based regenerative medicine may have the potential to dramatically promote the achievement of mucosal healing in refractory IBD patients, and thereby improve their long-term prognosis as well. So far, studies have shown that hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) may have some beneficial effect on IBD patients through their transplantation or transfusion. Recent advance in stem cell biology has added intestinal stem cells (ISCs) as a new player in this field. It has been shown that ISCs can be grown in vitro as organoids and that those ex-vivo cultured organoids can be employed as donor cells for transplantation studies. Further studies using mice colitis models have shown that ex-vivo cultured organoids can engraft onto the colitic ulcers and reconstruct the crypt-villus structures. Such transplantation of organoids may not only facilitate the regeneration of the refractory ulcers that may persist in IBD patients but may also reduce the risk of developing colitis-associated cancers. Endoscopy-assisted transplantation of organoids may, therefore, become one of the alternative therapies for refractory IBD patients.

Stem Cell Applications for Treatment of Cancer and Autoimmune Diseases: Its Promises, Obstacles, and Future Perspectives

Since the original discovery of stem cells, a new era of promising results has emerged in the clinical application of stem cells for the treatment of several important diseases, including cancer and autoimmune diseases. The plentiful research on stem cells during the past decades has provided significant information on the developmental, morphological, and physiological processes that govern tissue and organ formation, maintenance, and regeneration; cellular differentiation; molecular processes; and tissue homeostasis. In this review, we present the history of the use of stem cells in different clinical applications. Furthermore, we discuss the various therapeutic options for stem cells in cancer, followed by the role of stem cells in the treatment of autoimmune disorders. Additionally, we highlight the risks of and obstacles to the application of stem cells in clinical practice. Ultimately, we show future perspectives in stem cell use, with an aim to improve the clinical usefulness of stem cells.

Autologous Haematopoietic Stem Cell Transplantation for Crohn's Disease: A Retrospective Survey of Long-term Outcomes From the European Society for Blood and Marrow Transplantation

BACKGROUND AND AIMS

Autologous haematopoietic stem cell transplantation [AHSCT] is a therapeutic option for patients with severe, treatment-refractory Crohn's disease [CD]. The evidence base for AHSCT for CD is limited, with one randomised trial [ASTIC] suggesting benefit. The aim of this study was to evaluate safety and efficacy for patients undergoing AHSCT for CD in Europe, outside the ASTIC trial.

METHODS

We identified 99 patients in the European Society for Blood and Marrow Transplantation [EBMT] registry, who were eligible for inclusion. Transplant and clinical outcomes were obtained for 82 patients from 19 centres in seven countries.

RESULTS

Median patient age was 30 years [range 20-65]. Patients had failed or been intolerant to a median of six lines of drug therapy; 61/82 [74%] had had surgery. Following AHSCT, 53/78 [68%] experienced complete remission or significant improvement in symptoms at a median follow-up of 41 months [range 6-174]; 22/82 [27%] required no medical therapy at any point post-AHSCT. In patients who had re-started medical therapy at latest follow-up, 57% [24/42] achieved remission or significant symptomatic improvement with therapies to which they had previously lost response or been non-responsive. Treatment-free survival at 1 year was 54%. On multivariate analysis, perianal disease was associated with adverse treatment-free survival (hazard ratio 2.34, 95% confidence interval [CI] 1.14-4.83, p = 0.02). One patient died due to infectious complications [cytomegalovirus disease] at Day +56.

CONCLUSIONS

In this multicentre retrospective analysis of European centres, AHSCT was relatively safe and appeared to be effective in controlling otherwise treatment-resistant Crohn's disease. Further prospective randomised controlled trials against standard of care are warranted.

Mesenchymal Stem Cells to Treat Crohn's Disease with Fistula

Crohn's disease, which mainly affects the gastrointestinal tract, is a refractory inflammatory disease that has clinical manifestations of abdominal pain, fever, bowel obstruction, and diarrhea with blood or mucus. Together, these symptoms can severely impair a patient's quality of life. Besides the common complication of intestinal obstruction, fistulas, particularly anorectal fistulas, are common in Crohn's disease patients. Since radical surgical cures can be difficult to achieve and relapse is common, Crohn's disease patients often seek other effective treatments in addition to surgery. Stem-cell therapies have recently been proposed as a method to address the challenges and prospective medical needs of Crohn's disease patients in general and those with fistulas. Several studies suggest that mesenchymal stem cells (MSCs) could improve Crohn's disease and Crohn's fistula. Moreover, studies concerning MSC transplantation or local rejection of stem cells derived from bone marrow or adipose tissue-derived stem cells have assessed stem cell-based treatments for refractory Crohn's disease. Many patients in these studies are now in remission. A number of clinical trials for refractory Crohn's disease have also evaluated transplantation of autologous or allogenic MSCs and showed that MSCs can be safely administered to Crohn's disease patients, with some achieving positive clinical responses.

Efficacy and safety of autologous hematopoietic stem cell therapy for refractory Crohn's disease: A systematic review and meta-analysis

BACKGROUND

Autologous hematopoietic stem cell transplantation (HSCT) has been proposed for patients with refractory Crohn's disease (CD), but it is associated with mortality and adverse events; the balance between risks and benefits becomes significantly important in the therapy. The aim of the study was to assess the efficacy and safety of autologous HSCT therapy for refractory CD.

METHODS

We conducted a comprehensive search of PubMed, Embase, the Cochrane library, and Web of Science from inception to February 2017. The pooled estimate rates for efficacy and safety of refractory CD was performed by meta-analysis and reported according to the standard Cochrane guidelines and the PRISMA statement.

RESULTS

Four prospective uncontrolled cohort studies, 4 prospective case series, and 1 randomized controlled trial (RCT) were included. Autologous HSCT had a high rate of clinical and endoscopic remission in refractory CD [79.4%, 95% confidence interval (95% CI): 0.550-0.924; 81.9%, 95% CI: 0.603-0.931, respectively]. In the case of safety, it had a relatively high incidence rate of transplant-related mortality (6.4%, 95% CI: 0.028-0.140). A significant association was observed between autologous HSCT and the incidence of febrile neutropenia (83.2%, 95% CI: 0.632-0.934). About 18.5% (95% CI: 0.061-0.442) of patients with refractory CD reached clinical remission at mobilization phase. Besides, 82.1% (95% CI: 0.692-0.903) and 54.1% (95% CI: 0.261-0.797) patients with refractory CD could achieve immunosuppressive-free and steroid-free remission for at least 12 months after the therapy.

CONCLUSION

Autologous HSCT could be a complicated treatment with relatively high mortality and significantly high efficacy for refractory CD, which should be used with caution. However, more RCTs of larger samples using refined and standardized protocols and longer period of follow-up time are needed to further assess the outcomes of autologous HSCT therapy.

Anti-thymocyte serum as part of an immunosuppressive regimen in treating haematological immune-mediated diseases in dogs

OBJECTIVES

To report the outcomes associated with the use of rabbit anti-dog thymocyte serum in dogs with haematological immune-mediated diseases.

METHODS

Medical records from 2000 to 2016 of patients diagnosed with immune-mediated haemolytic anaemia, immune-mediated thrombocytopenia, pancytopenia and myelofibrosis were reviewed. All dogs had a severe or refractory disease and received rabbit anti-dog thymocyte serum. Lymphocyte counts were used to monitor the immediate anti-thymocyte effect of therapy; long-term patient outcome was recorded.

RESULTS

A total of 10 dogs were included. All dogs except one had a notable decrease in their lymphocyte count after rabbit anti-dog thymocyte serum; four of nine had a decrease to less than 10% of the initial lymphocyte count and one dog reached 10·8%. All dogs were discharged from the hospital following their treatment. The dog with no alteration of lymphocyte count following therapy with rabbit anti-dog thymocyte serum had refractory immune mediated haemolytic anemia and was euthanised within two weeks. All other cases achieved clinical remission with immunosuppressive therapy eventually being tapered (3 of 10) or discontinued (6 of 10).

CLINICAL SIGNIFICANCE

Rabbit anti-dog thymocyte serum therapy might be of interest as an adjunctive therapy in refractory immune-mediated diseases and suppressed lymphocyte counts in most dogs.

Autologous hematopoietic stem cells for refractory Crohn's disease

INTRODUCTION

Autologous hematopoietic stem cells are gaining ground as an effective and safe treatment for treating severe refractory Crohn's disease (CD). Autologous hematopoietic stem cell therapy (AHSCT) induces resetting of the immune system by de novo regeneration of T-cell repertoire and repopulation of epithelial cells by bone-marrow derived cells to help patients achieve clinical and endoscopic remission. Areas covered: Herein, the authors discuss the use of AHSCT in treating patients with CD. Improvements in disease activity have been seen in patients with severe autoimmune disease and patients with severe CD who underwent AHSCT for a concomitant malignant hematological disease. Clinical and endoscopic remission has been achieved in patients treated with AHSCT for CD. The only randomized trial published to date, the ASTIC Trial, did not support further use of AHSCT to treat CD. Yet, critics of this trial have deemed AHSCT as a promising treatment for severe refractory CD. Expert opinion: Even with the promising evidence presented for HSCT for refractory CD, protocols need to be refined through the collaboration of GI and hemato-oncology professionals. The goal is to incorporate safe AHSCT and restore tolerance by delivering an effective immune 'cease fire' as a treatment option for severe refractory CD.

Investigating cell therapy for inflammatory bowel disease

INTRODUCTION

Advances in immuno-modulatory therapies, including anti-TNF-α therapies, have greatly increased the chance to achieve long-term remission of inflammatory bowel disease (IBD) patients. However, as the importance of mucosal healing has been demonstrated in a number of clinical studies, new cell-based therapies that can regenerate and fully restore the intestinal mucosal functions are currently under development.

AREA COVERED

In this review, we feature the recent challenges of cell-based therapies that are applied to the treatment of IBD. In particular, we will focus on hematopoietic stem cells (HSC), mesenchymal stem cells (MSCs) and intestinal stem cells (ISCs) as the candidate source for cell-based therapy targeted to treat IBD. The current status, as well as the expected advantages and disadvantages of those transplantations will be summarized and discussed.

EXPERT OPINION

Transplantation of HSC, MSC and ISC may have different levels of potential in their ability to exert an immunomodulatory or pro-regenerative effect. Combined cell therapies, such as co-transplantation of MSC and ISC, may provide improved therapeutic outcome compared to transplantation of a single cell population. Those cell-based therapies may not only improve the disease activity or tissue regeneration, but may also have the potential to decrease the risk of developing colitis-associated cancers.

Concise Review: Cellular Therapies: The Potential to Regenerate and Restore Tolerance in Immune-Mediated Intestinal Diseases

Chronic inflammatory enteropathies, including celiac disease, Crohn's disease, and ulcerative colitis, are lifelong disabling conditions whose cure is still an unmet need, despite the great strides made in understanding their complex pathogenesis. The advent of cellular therapies, mainly based on the use of stem cells, represents a great step forward thanks to their multitarget strategy. Both hematopoietic stem cells (HSC) and mesenchymal stem/stromal cells (MSC) have been employed in the treatment of refractory cases with promising results. The lack of immunogenicity makes MSC more suitable for therapeutic purposes as their infusion may be performed across histocompatibility locus antigen barriers without risk of rejection. The best outcome has been obtained when treating fistulizing Crohn's disease with local injections of MSC. In addition, both HSC and MSC proved successful in promoting regeneration of intestinal mucosa, and favoring the expansion of a T-cell regulatory subset. By virtue of the ability to favor mucosal homeostasis, this last cell population has been exploited in clinical trials, with inconsistent results. Finally, the recent identification of the epithelial stem cell marker has opened up the possibility of tissue engineering, with an array of potential applications for intestinal diseases. However, the underlying mechanisms of action of these interconnected therapeutic strategies are still poorly understood. It is conceivable that over the next few years their role will become clearer as the biological interactions with injured tissues and the hierarchy by which they deliver their action are unraveled through a continuous moving from bench to bedside and vice versa. Stem Cells 2016;34:1474-1486.

Stem cell therapy for inflammatory bowel disease

Inflammatory bowel disease (IBD) could be curable by "immune rest" and correction of the genetic predisposition inherent in allogeneic hematopoietic stem cell transplantation. However, balancing risks against benefits remains challenging. The application of mesenchymal stem cells (MSCs) serving as a site-regulated "drugstore" is a recent concept, which suggests the possibility of an alternative treatment for many intractable diseases such as IBD. Depending on the required function of MSC, such as a cell provider, immune moderator, and/or trophic resource, MSC therapy should be optimized to maximize its therapeutic benefit. Therapeutic effects do not always require full engraftment of MSCs. Therefore, optimization of pleiotropic gut trophic factors produced by MSCs, which favoring not only regulating immune responses but also promoting tissue repair, must directly enhance new drug discoveries for treatment of IBD. Stem cell biology holds great promise for a new era of cell-based therapy, sparking considerable interest among scientists, clinicians, and patients. However, the translational arm of stem cell science remains in a relatively primitive state. Although several clinical studies using MSCs have been initiated, early results suggest several inherent problems. In each study, optimization of MSC therapy appears to be the most urgent problem, and can be resolved only by scientifically unveiling the mechanisms of therapeutic action. In the present review, the authors outline how such information would facilitate the critical steps in the paradigm shift from basic research on stem cell biology to clinical practice of regenerative medicine for conquering IBD in the near future.

Hematopoietic stem cell transplantation for non-malignant gastrointestinal diseases

Both, autologous and allogeneic hematopoietic stem cell transplantation (HSCT) can be used to cure or ameliorate a variety of malignant and non-malignant diseases. The rationale behind this strategy is based on the concept of immunoablation using high-dose chemotherapy, with subsequent regeneration of naive T-lymphocytes derived from reinfused hematopoietic progenitor cells. In addition, the use of HSCT allows for the administration of high-dose chemotherapy (whether or not combined with immunomodulating agents such as antithymocyte globulin) resulting in a prompt remission in therapy-refractory patients. This review gives an update of the major areas of successful uses of HSCT in non-malignant gastrointestinal disorders. A Medline search has been conducted and all relevant published data were analyzed. HSCT has been proved successful in treating refractory Crohn’s disease (CD). Patients with refractory celiac disease type II and a high risk of developing enteropathy associated T-cell lymphoma have shown promising improvement. Data concerning HSCT and mesenchymal SCT in end-stage chronic liver diseases are encouraging. In refractory autoimmune gastrointestinal diseases high-dose chemotherapy followed by HSCT seems feasible and safe and might result in long-term improvement of disease activity. Mesenchymal SCT for a selected group of CD is promising and may represent a significant therapeutic alternative in treating fistulas in CD.

Advancements in gene transfer-based therapy for hemophilia A

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

In vivo reprogramming in inflammatory bowel disease

The direct reprogramming of somatic cells has immense implications in various areas of medicine. Although remarkable progress has been made in developing novel reprogramming methods, the efficiency and fidelity of reprogramming still need to be improved. Inflammatory bowel disease (IBD) involves chronic inflammatory diseases of the gastrointestinal tract with a complex etiology caused by various genetic, immunological and environmental factors. Recently, the role of stem cells has been proposed in pathogenesis and therapy of IBD. However, the efficiency and the safety of the stem cell treatments depend on the origin of the stem cell and the administration method. We hypothesize that the reprogramming of the intestinal cells into a pluripotent state is of huge importance for IBD therapy and prevention. The vectors carrying reprogramming genes encoding pluripotency factors can be transferred to the damaged tissue, in this case the intestine, by means of invasive bacterial vectors able to colonize colon mucosa. Reconstruction of tissues in vivo might avoid problems encountered in tissue rebuilding in vitro because of lack of appropriate scaffolds and microenvironments. Herein we present a review of recent literature and a perspective of in vivo reprogramming in IBD using bacterial vectors and analyze the rationale for such approach.

Remission of refractory Crohn's disease by high-dose cyclophosphamide and autologous peripheral blood stem cell transplantation

BACKGROUND

Despite advances in immunosuppressive therapy, up to 10% of patients with severe Crohn's disease (CD) remain refractory to conventional treatment. Limited evidence from pilot trials suggests that high-dose immunosuppression and autologous peripheral blood stem cell transplantation (autoPBSCT) may induce remission in these patients, but there is substantial controversy regarding the safety and efficacy of this approach.

AIM

To address this issue, a monocentre phase I/II trial of autoPBSCT was performed in patients with refractory CD in our hospital.

METHODS

Here, we report on the outcome of 12 patients with refractory CD treated with autoPBSCT. Briefly, CD34(+) -selected PBSCs were harvested after mobilisation therapy with cyclophosphamide and granulocyte-colony stimulating factor. Later, immunoablative conditioning therapy with high-dose cyclophosphamide followed by autoPBSCT was applied and clinical and endoscopic responses were analysed after a mean follow-up of 3.1 years (range 0.5-10.3 years).

RESULTS

PBSC harvest following mobilisation chemotherapy was successful in 11/12 patients and resulted in a clinical and endoscopic improvement in 7/12 patients. Subsequent conditioning and autoPBSCT were performed in nine patients and were relatively well tolerated. Among those, five patients achieved a clinical and endoscopic remission within 6 months after autoPBSCT. However, relapses occurred in 7/9 patients during follow-up, but disease activity could be controlled by low-dose corticosteroids and conventional immunosuppressive therapy.

CONCLUSION

Immunoablation by cyclophosphamide and autologous peripheral blood stem cell transplantation is safe and effective to induce remission of refractory Crohn's disease, and should be further evaluated in randomised controlled trials.

Autologous cord blood harvesting in North Eastern Italy: ethical questions and emerging hopes for curing diabetes and celiac disease

Background

The Friuli Venezia Giulia (FVG), a region of North Eastern Italy, has passed legislation (Decree No 2324/2010) to regulate the banking of umbilical cord blood samples for personal, autologous, or family-directed use, and to implement the Agreement of the State-Regions Permanent Conference (Decree No 62/CSR/2010). This paper aims to identify the formalities and the reasons why families collect and bank their cord blood in foreign banks for both personal and private use.

Methods

To this end, at the Institute for Maternal and Child Health of Trieste (the regional capital city of the FVG), Italy, which assists about 1800 pregnant women a year, 129 questionnaires, drafted from January 2010 to December 2011 and concerning the granting of authorization to export samples, were examined.

Results

The collected data showed that 75% of involved families had resorted to anonymous public collection, which is available to anyone with therapeutic needs, and provided compatibility and hematologic protocols recognized by the scientific and international community (main indications: leukemia, hemoglobinopaties, and inherited hematologic and immunologic disorders). Conversely, 25.0% requested private storage at a foreign bank for personal or family-dedicated use. The principal motivation by disease was for treatment for diabetes (22.4%) and celiac disease (19.7%) (a multiorgan disease for which the FVG region has provided safeguards by approving a specific law granting support to families; Decree No 561/2007). For these two types of disease we found that information was received from the internet and not from general medical physicians, with a significant difference found using the χ² test (P < 0.01).

Conclusion

The indication of treating these diseases with cord blood stem cell transplantation appears to be well grounded and encouraging, and has recently been corroborated by the international literature; however, the economic and social motivations promoting cord blood storage, for a fee, in the event of diseases that are still under study, require accurate information through general medical physicians on the actual possibilities of treatment.

Transplantation for autoimmune diseases in north and South America: a report of the Center for International Blood and Marrow Transplant Research

Hematopoietic cell transplantation (HCT) is an emerging therapy for patients with severe autoimmune diseases (AID). We report data on 368 patients with AID who underwent HCT in 64 North and South American transplantation centers reported to the Center for International Blood and Marrow Transplant Research between 1996 and 2009. Most of the HCTs involved autologous grafts (n = 339); allogeneic HCT (n = 29) was done mostly in children. The most common indications for HCT were multiple sclerosis, systemic sclerosis, and systemic lupus erythematosus. The median age at transplantation was 38 years for autologous HCT and 25 years for allogeneic HCT. The corresponding times from diagnosis to HCT were 35 months and 24 months. Three-year overall survival after autologous HCT was 86% (95% confidence interval [CI], 81%-91%). Median follow-up of survivors was 31 months (range, 1-144 months). The most common causes of death were AID progression, infections, and organ failure. On multivariate analysis, the risk of death was higher in patients at centers that performed fewer than 5 autologous HCTs (relative risk, 3.5; 95% CI, 1.1-11.1; P = .03) and those that performed 5 to 15 autologous HCTs for AID during the study period (relative risk, 4.2; 95% CI, 1.5-11.7; P = .006) compared with patients at centers that performed more than 15 autologous HCTs for AID during the study period. AID is an emerging indication for HCT in the region. Collaboration of hematologists and other disease specialists with an outcomes database is important to promote optimal patient selection, analysis of the impact of prognostic variables and long-term outcomes, and development of clinical trials.

Reappraisal of total body irradiation followed by bone marrow transplantation as a therapy for inflammatory bowel disease

The main current therapies for inflammatory bowel diseases (IBD) are aimed at controlling the exacerbated inflammation in the gut. Although these therapies have been successful, they are not curative and it is not possible to predict whether a beneficial response will occur or which patients will be refractory to the treatment. Total body irradiation (TBI) associated with chemotherapy is the first choice in the treatment of some hematological disorders and is an applicable option in the preparation of patients with hematologic diseases for hematopoietic stem cell transplantation. Then, in this study we investigated the association of TBI as immunosuppressive therapy and bone marrow cell (BMC) transplantation as a strategy to induce colitis recovery and immune reconstitution in the TNBS model of intestinal inflammation. TNBS mice treated with TBI associated with BMC transplantation presented elevated gain of weight and an overall better outcome of the disease when compared to those treated only with TBI. In addition, TBI associated or not with BMC reduced the frequency of inflammatory cells in the gut and restored the goblet cell counts. These results were accompanied by a down regulation in the production of inflammatory cytokines in the colon of mice treated with TBI alone or in association with BMC transplantation. The BMC infused were able to repopulate the ablated immune system and accumulate in the site of inflammation. However, although both treatments (TBI or TBI+BMC) were able to reduce gut inflammation, TBI alone was not enough to fully restore mice weight and these animals presented an extremely reduced survival rate when their immune system was not promptly reconstituted with BMC transplantation. Finally, these evidences suggest that the BMC transplantation is an efficient strategy to reduce the harmful effects of TBI in the colitis treatment, suggesting that radiotherapy may be an important immunosuppressive therapy in patients with IBD, by modulating the local inflammatory response.

Hyperbaric oxygen treatment for inflammatory bowel disease: a systematic review and analysis

Background

Traditionally, hyperbaric oxygen treatment (HBOT) has been used to treat a limited repertoire of disease, including decompression sickness and healing of problem wounds. However, some investigators have used HBOT to treat inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis.

Methods

Comprehensive searches were conducted in 8 scientific databases through 2011 to identify publications using HBOT in IBD. Human studies and animal models were collated separately.

Results

Thirteen studies of HBOT in Crohn's disease and 6 studies in ulcerative colitis were identified. In all studies, participants had severe disease refractory to standard medical treatments, including corticosteroids, immunomodulators and anti-inflammatory medications. In patients with Crohn's disease, 31/40 (78%) had clinical improvements with HBOT, while all 39 patients with ulcerative colitis improved. One study in Crohn's disease reported a significant decrease in proinflammatory cytokines (IL-1, IL-6 and TNF-alpha) and one study in ulcerative colitis reported a decrease in IL-6 with HBOT. Adverse events were minimal. Twelve publications reported using HBOT in animal models of experimentally-induced IBD, including several studies reporting decreased markers of inflammation or immune dysregulation, including TNF-alpha (3 studies), IL-1beta (2 studies), neopterin (1 study) and myeloperoxidase activity (5 studies). HBOT also decreased oxidative stress markers including malondialdehyde (3 studies) and plasma carbonyl content (2 studies), except for one study that reported increased plasma carbonyl content. Several studies reported HBOT lowered nitric oxide (3 studies) and nitric oxide synthase (3 studies) and one study reported a decrease in prostaglandin E₂ levels. Four animal studies reported decreased edema or colonic tissue weight with HBOT, and 8 studies reported microscopic improvements on histopathological examination. Although most publications reported improvements with HBOT, some studies suffered from limitations, including possible publication and referral biases, the lack of a control group, the retrospective nature and a small number of participants.

Conclusions

HBOT lowered markers of inflammation and oxidative stress and ameliorated IBD in both human and animal studies. Most treated patients were refractory to standard medical treatments. Additional studies are warranted to investigate the effects of HBOT on biomarkers of oxidative stress and inflammation as well as clinical outcomes in individuals with IBD.

Stem cells in clinical practice: applications and warnings

Stem cells are a relevant source of information about cellular differentiation, molecular processes and tissue homeostasis, but also one of the most putative biological tools to treat degenerative diseases. This review focuses on human stem cells clinical and experimental applications. Our aim is to take a correct view of the available stem cell subtypes and their rational use in the medical area, with a specific focus on their therapeutic benefits and side effects. We have reviewed the main clinical trials dividing them basing on their clinical applications, and taking into account the ethical issue associated with the stem cell therapy.

Stem cell transplantation for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is comprised of ulcerative colitis and Crohn's disease and characterized by chronic inflammation of the intestinal tract. The etiology of IBD is still unknown. Traditional treatment mainly controls active inflammation and regulates immunologic derangements. Commonly used drugs include 5-aminosalicylic acid, glucocorticoid and immunosuppressant. Some cases of IBD require surgical treatment eventually. Due to multipe etiologies, IBD should be managed comprehensively. The appearance of biological agents, genetically modified methods, anticoagulant therapies, and stem cell transplantation therapies has made it more likely to cure IBD. Stem cell transplantation represents a new type of treatment for IBD. In this article, we review the role of stem cell transplantation in the treatment of IBD.

Targeting the CXCR4-CXCL12 axis mobilizes autologous hematopoietic stem cells and prolongs islet allograft survival via programmed death ligand 1

Antagonism of CXCR4 disrupts the interaction between the CXCR4 receptor on hematopoietic stem cells (HSCs) and the CXCL12 expressed by stromal cells in the bone marrow, which subsequently results in the shedding of HSCs to the periphery. Because of their profound immunomodulatory effects, HSCs have emerged as a promising therapeutic strategy for autoimmune disorders. We sought to investigate the immunomodulatory role of mobilized autologous HSCs, via target of the CXCR4-CXL12 axis, to promote engraftment of islet cell transplantation. Islets from BALB/c mice were transplanted beneath the kidney capsule of hyperglycemic C57BL/6 mice, and treatment of recipients with CXCR4 antagonist resulted in mobilization of HSCs and in prolongation of islet graft survival. Addition of rapamycin to anti-CXCR4 therapy further promoted HSC mobilization and islet allograft survival, inducing a robust and transferable host hyporesponsiveness, while administration of an ACK2 (anti-CD117) mAb halted CXCR4 antagonist-mediated HSC release and restored allograft rejection. Mobilized HSCs were shown to express high levels of the negative costimulatory molecule programmed death ligand 1 (PD-L1), and HSCs extracted from wild-type mice, but not from PD-L1 knockout mice, suppressed the in vitro alloimmune response. Moreover, HSC mobilization in PD-L1 knockout mice failed to prolong islet allograft survival. Targeting the CXCR4-CXCL12 axis thus mobilizes autologous HSCs and promotes long-term survival of islet allografts via a PD-L1-mediated mechanism.

Immunotherapy of systemic sclerosis

Scleroderma is a multisystem autoimmune disease characterized by an abnormal immune activation associated with the development of underlying vascular and fibrotic disease manifestations. This article highlights the current use of drugs targeting the immune system in scleroderma. Nonselective immunosuppression, and in particular cyclophosphamide, remains the main treatment for progressing skin involvement and active interstitial lung disease. Mycophenolate mofetil is a promising alternative to cyclophosphamide. The use of cyclosporine has been limited by modest efficacy and serious renal toxicity. Newer T-cell (sirolimus and alefacept) and B-cell (rituximab)-targeted therapies have provided some encouraging results in small pilot studies. Hematopoietic stem cell transplantation can be effective for severe fibrotic skin disease, but toxicity remains a concern. Clinical efficacy and safety of antifibrotic treatments (e.g., imatinib) await confirmation. Newer biological agents targeting key molecular or cellular effectors in scleroderma pathogenesis are now available for clinical testing.

Biological therapies of inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by increasing morbidity and, if suboptimally treated, poor prognosis. Recent evidence strongly suggests that dysfunctional immune responses play an important role in the pathogenesis of IBD. Therefore, immunologically downregulating the overactivated innate and adaptive immune responses may be a better approach to treat IBD than currently used pharmaceutical therapies. In recent years, many new biological therapies have been developed. These therapies are shown to be effective for inducing remission, preventing complications, improving life quality of the patients, and reducing hospitalization and surgical rates. This article introduces and discusses these new biological agents that have been used effectively in clinic for IBD patients.

Stem cells as potential therapeutic targets for inflammatory bowel disease

The incidence and prevalence of Crohn's disease and ulcerative colitis, the two major forms of inflammatory bowel disease (IBD), are rising. According to some estimates >1 million new cases of IBD arise in the United States annually. The conventional therapies available for IBD range from anti-inflammatory drugs to immunosuppressive agents, but these therapies generally fail to achieve satisfactory results due to their side effects. Interest in a new therapeutic option, that is, biological therapy, has gained much momentum recently due to its focus on different stages of the inflammatory process. Stem cell (SC) research has become a new direction for IBD therapy due to our recent understanding of cell populations involved in the pathogenic process. To this end, hematopoietic and mesenchymal stem cells are receiving more attention from IBD investigators. The intestinal environment, with its crypts and niches, supports incoming embryonic and hematopoietic stem cells and allows them to engraft and differentiate. The above findings suggest that, in the future, SC-based therapy will be a promising alternative to conventional therapy for IBD. In this review, we discuss SCs as potential therapeutic targets for future treatment of IBD.

Contribution of bone marrow-derived cells to the pro-inflammatory effects of protease-activated receptor-2 in colitis

Objective

Our aim was to determine the contribution of proteinase-activated receptor-2 (PAR₂)-expressing bone marrow-derived cells on the development of colonic inflammation.

Materials

Chimeric mice were generated by injecting bone marrow cells from wildtype (PAR₂^+/+) or PAR₂ knockout mice (PAR₂^−/−) into irradiated PAR₂^+/+ or PAR₂^−/− mice. Treatments: Colitis was induced by giving 2.5% dextran sodium sulfate (DSS) solution for 7 days or by a single intracolonic administration of trinitrobenzene sulphonic acid (TNBS, 2 mg dissolved in 40% ethanol).

Methods

Seven days after the induction of colitis, bowel thickness, inflammatory parameters [myeloperoxidase (MPO) activity, macroscopic/microscopic damage scores], and leukocyte trafficking (visualized via intravital microscopy) were assessed.

Results

Total deficiency of PAR₂ resulted in a marked reduction in severity of both TNBS and DSS induced colitis as assessed by MPO activity, macroscopic damage, bowel thickness, and leukocyte adherence. Colitis was attenuated in all chimeric lines in which there was loss of PAR₂ in the host, non-bone marrow-derived tissue, independent of the status of PAR expression by bone marrow-derived cells. Interestingly, TNBS colitis was attenuated in PAR₂^+/+ chimeric mice with PAR₂^−/− derived bone marrow but these animals were not protected from DSS colitis.

Conclusions

Expression of PAR₂ by host-derived tissues plays a dominant role in regulating colonic inflammation. PAR₂ expression by bone marrow-derived cells appears to play a role in TNBS colitis but not in DSS induced injury.

Electronic supplementary material

The online version of this article (doi:10.1007/s00011-010-0181-9) contains supplementary material, which is available to authorized users.

Therapeutic leukocytapheresis in inflammatory bowel disease: clinical efficacy and mechanisms of action

Intense infiltration of the intestinal mucosa by activated leukocytes is a hallmark of inflammatory bowel disease (IBD). Therefore, removal of circulating leukocytes may be an attractive approach for treating IBD. Leukocytapheresis with Cellsorba, a column of polyethylenephtarate fibers that captures monocytes, granulocytes and lymphocytes, has been used to treat IBD, particularly ulcerative colitis, in Japan and Europe. This article reviews the clinical efficacy and safety data and the mechanisms of action of leukocytapheresis in IBD. Although the majority of clinical studies enrolled only small numbers of patients and had open-labeled designs, leukocytapheresis showed clinical efficacy with an excellent safety profile. Leukocytapheresis depletes granulocytes, monocytes, lymphocytes and platelets, alters cell population profiles, modulates cytokine production, and induces bone marrow-derived cells. In conclusion, leukocytapheresis exerts anti-inflammatory and tissue-repairing effects on the intestinal mucosa in IBD. Further studies are needed to explain the exact mechanism of action and to determine the true efficacy of this approach.

Inflammatory bowel disease: Moving toward a stem cell-based therapy

The incidence and prevalence of Crohn's disease (CD) and ulcerative colitis (UC), the two major forms of inflammatory bowel diseases (IBD), are rising in western countries. The modern hygienic lifestyle is probably at the root of a disease where, in genetically susceptible hosts, the intestinal commensal flora triggers dysregulated immune and inflammatory responses. Current therapies ranging from anti-inflammatory drugs to immunosuppressive regimens, remain inadequate. Advances in our understanding of the cell populations involved in the pathogenetic processes and recent findings on the regenerative, trophic and immunoregulatory potential of stem cells open new paths in IBD therapy. Hematopoietic and mesenchymal stem cells are catalyzing the attention of IBD investigators. This review highlights the pivotal findings for stem cell-based approaches to IBD therapy and collects the encouraging results coming in from clinical trials.

Mobilization of bone marrow cells by leukocytapheresis in patients with ulcerative colitis

While several trials have suggested that leukocytapheresis by filtration can benefit patients with active ulcerative colitis (UC), mechanisms underlying these benefits are largely unknown. We studied how leukocytapheresis mobilizes bone marrow cells into the peripheral circulation in patients with active UC. Leukocytapheresis transiently reduced peripheral leukocytes, followed by an overshoot increase with emergence of immature leukocytes. The numbers of colonies and CD34(+) cells were comparable between UC patients and normal controls. Shortly after leukocytapheresis, the numbers of both colonies and CD34(+) cells increased significantly in UC patients (P < 0.0001 and P = 0.0372, respectively). This was not associated with changes in the concentration of circulating cytokines or epinephrine. These results indicate that leukocytapheresis mobilizes bone marrow cells into the circulation. This cell replacement may partly explain the therapeutic benefit in UC. The functional role of the mobilized bone marrow cells in affected intestine remains to be characterized.

Phagocyte dysfunction and inflammatory bowel disease

Inflammatory bowel diseases are common chronic inflammatory disorders. The majority are idiopathic and can be broadly divided into Crohn's disease and ulcerative colitis. Their cause is unknown, but most hypotheses focus on a primary role for T-cell dysfunction. Conversely, there is a collection of congenital disorders of phagocyte function that result not only in immunodeficiency but also in noninfectious inflammatory bowel disease. In all cases, the latter is strikingly reminiscent of the clinical and pathological features of Crohn's disease. This coincides with recent work demonstrating that despite previous emphasis on adaptive immune dysfunction, patients with Crohn's disease actually possess an unusually weak acute innate inflammatory response. This review consolidates the literature on inflammatory bowel disease in congenital immunodeficiencies and considers the role of phagocyte dysfunction in Crohn's disease. Concepts about pathogenesis and treatment that can be carried across these disorders are also discussed.

Inflammatory bowel disease: Moving toward a stem cell-based therapy

The incidence and prevalence of Crohn's disease (CD) and ulcerative colitis (UC), the two major forms of inflammatory bowel diseases (IBD), are rising in western countries. The modern hygienic lifestyle is probably at the root of a disease where, in genetically susceptible hosts, the intestinal commensal flora triggers dysregulated immune and inflammatory responses. Current therapies ranging from anti-inflammatory drugs to immunosuppressive regimens, remain inadequate. Advances in our understanding of the cell populations involved in the pathogenetic processes and recent findings on the regenerative, trophic and immunoregulatory potential of stem cells open new paths in IBD therapy. Hematopoietic and mesenchymal stem cells are catalyzing the attention of IBD investigators. This review highlights the pivotal findings for stem cell-based approaches to IBD therapy and collects the encouraging results coming in from clinical trials.

[Stem cell transplantation in the treatment of gastrointestinal diseases]

The stem cells with self-renewal ability are capable to form one or more cell types. They will be in the target of cell and gene therapy because of their multipotency and easy retrieval. Application of adult mesenchymal, neuronal, epidermal and haematopoietic stem cell can be favourable in the treatment of cardiac (myocardial infarction), bone (osteoarthritis), neurological (Parkinson's, Alzheimer's) and hematological (hemophilia, thrombocytopenia) disorders. Authors summarize the knowledge in connection with their application in the therapy of gastrointestinal diseases. Haematopoietic stem cell transplantation has been successful for the treatment of refractory Crohn's disease, as well as in selected group of celiac patients. Mesenchymal stem cell transplantation has been proved beneficial in the prevention of liver fibrotic process. It will gain more grounds in the treatment of autoimmune liver diseases: autoimmune hepatitis, primary biliary cirrhosis and primary sclerosing cholangitis in the future. Well-designed, multicentric, prospective studies are needed to confirm the results of case reports and clinical studies with small group of patients.

Stem cells as potential novel therapeutic strategy for inflammatory bowel disease

Hematopoietic stem cell transplantation and mesenchymal stromal cell therapy are currently under investigation as novel therapies for inflammatory bowel diseases. Hematopoietic stem cells (HSC) are thought to repopulate the immune system and reset the immunological response to luminal antigens. Mesenchymal stromal cells (MSC) are cells that have the capacity to differentiate into wide variety of distinct cell lineages and suppress immune responses in vitro and in vivo. Recent results from animal models and early human experience in graft-versus-host disease but also Crohn's Disease suggest that ex vivo expanded MSCs may have clinically useful immunomodulatory effects.

Treatment of intractable ulcerating enterocolitis of infancy by allogeneic bone marrow transplantation

BACKGROUND & AIMS

Intractable ulcerating enterocolitis of infancy (IE) is an uncommon, autosomal-recessive, and devastating inflammatory bowel disorder that arises as a consequence of a poorly defined underlying immunologic disorder. Infants with IE suffer from recurrent severe oro-anal disease and an enterocolitis that is unresponsive to conventional immunosuppressive therapy and requires early pancolectomy to control the severity of the disease. Despite such aggressive treatment these individuals remain at high risk of Epstein-Barr virus-driven lymphomatous proliferations, including non-Hodgkin's lymphoma. The underlying genetic basis for this disease remains undefined. This report aims to describe the use of bone marrow transplantation as a treatment for this condition.

METHODS

This was a case series report.

RESULTS

We describe the successful treatment of IE by allogeneic bone marrow transplantation in 2 brothers, now aged 7 and 11 years, one of whom had developed an Epstein-Barr virus-related monomorphous B-lymphocyte lymphoproliferative disorder. This treatment has resulted in prolonged clinical remission in both boys and abrogated the need for aggressive immunosuppression.

CONCLUSIONS

Bone marrow transplantation can be used for the treatment of intractable ulcerating enterocolitis of infancy, which may support a role in other intractable inflammatory bowel conditions in the pediatric population.

Novel therapeutic options in the inflammatory bowel disease world

Advances in the understanding of the pathogenesis of inflammatory bowel disease have encouraged the development of many new therapies targeted at specific and non-specific mediators of the inflammatory bowel disease inflammatory pathway. The role of these therapies, including novel anti-tumour necrosis factor-alpha agents, anti-adhesion molecules, recombinant cytokines, myeloid growth factors, helminths, and probiotics, in the management of paediatric onset inflammatory bowel disease is promising and warrants further investigation.

Review article: Stem cell transplantation for the treatment of gastrointestinal diseases--current applications and future perspectives

BACKGROUND

Haematopoietic stem cell transplantation (HSCT) can be used to cure or ameliorate a variety of non-malignant diseases. These range from inherent defects of haematopoiesis, through metabolic diseases, to severe autoimmune diseases. The rationale for this strategy is based on the concept of immunoablation using high-dose chemotherapy, with subsequent regeneration of naïve T-lymphocytes derived from reinfused haematopoietic progenitor cells. Possibly the use of SCT allows the administration of high-dose chemotherapy resulting in a prompt remission in these therapy-refractory patients.

AIM

This review highlights the major scientific developments and defines the areas of successful use of HSCT in gastrointestinal disorders and gives a perspective on possible future applications.

METHODS

A search in the Medline has been conducted and all relevant published data were analysed.

RESULTS

HSCT has been proved successful in treating refractory Crohn's disease. A selected group of refractory coeliac patients having a high risk of developing enteropathy associated T-cell lymphoma has been recently treated with promising results. In cryptogenic cirrhosis, basic research and unpublished data concerning mesenchymal SCT are encouraging.

CONCLUSION

In refractory autoimmune gastrointestinal diseases, it seems that high-dose chemotherapy followed by HSCT is feasible and safe and might result in long-term improvement of disease activity.

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

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

Role of intestinal subepithelial myofibroblasts in inflammation and regenerative response in the gut

Inflammatory bowel disease (IBD) is characterized by an ongoing mucosal inflammation caused by a dysfunctional host immune response to commensal microbiota and dietary factors. In the pathophysiology of IBD, mesenchymal cells such as intestinal subepithelial myofibroblasts (ISEMF) affect the recruitment, retention and activation of immune cells. Mesenchymal cells also promote resolution of inflammatory activity accompanied with balanced repair processes. The transient appearance of mesenchymal cells is a feature of normal wound healing, but the persistence of these cells is associated with tissue fibrosis. Recent studies suggest that mesenchymal cells derived from bone marrow (BM) stem cells play a crucial role in intestinal repair and fibrosis. This article focuses on recent knowledge about ISEMF in the field of immune response inflammation and repair. Two major topics were documented: interaction between interleukin (IL)-17-secreting CD4+ cells (Th-17 cells) and about role of BM-derived stem cells in mucosal regenerative response via differentiation to ISEMF. Recent therapeutic strategies targeting BM stem cells for IBD patients were also documented.