Immune Reconstitution After Autologous Hematopoietic Stem Cell Transplantation in Crohn's Disease: Current Status and Future Directions. A Review on Behalf of the EBMT Autoimmune Diseases Working Party and the Autologous Stem Cell Transplantation In Refractory CD-Low Intensity Therapy Evaluation Study Investigators

Cell Therapy as a Way to Increase the Effectiveness of Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is a standard method for treating a number of pathologies, primarily blood diseases. Timely restoration of the immune system after HSCT is a critical factor associated with the development of complications such as relapses or secondary tumors and various infections, as well as the graft-versus-host reaction in allogeneic transplantation, which ultimately affects the survival of patients. Introduction into the recipient's body of immune system cells that are incapable of sensitization by recipient antigens during the period of immune reconstitution can increase the rate of restoration of the immune system, as well as reduce the risk of complications. This review presents the results of studies on cell therapy with various cell subpopulations of both bone marrow and mesenchymal origin during HSCT.

Stem cell-based therapy for systemic lupus erythematous

Systemic lupus erythematosus (SLE), an autoimmune disease, is among the most prevalent rheumatic autoimmune disorders. It affects autologous connective tissues caused by the breakdown of self-tolerance mechanisms. During the last two decades, stem cell therapy has been increasingly considered as a therapeutic option in various diseases, including parkinson's disease, alzheimer, stroke, spinal cord injury, multiple sclerosis, inflammatory bowel disease, liver disease, diabete, heart disease, bone disease, renal disease, respiratory diseases, and hematological abnormalities such as anemia. This is due to the unique properties of stem cells that divide and differentiate to the specialized cells in the damaged tissues. Moreover, they impose immunomodulatory properties affecting the diseases caused by immunological abnormalities such as rheumatic autoimmune disorders. In the present manuscript, efficacy of stem cell therapy with two main types of stem cells, including mesenchymal stem cell (MSC), and hematopoietic stem cells (HSC) in animal models or human patients of SLE, has been reviewed. Taken together, MSC and HSC therapies improved the disease activity, and severity in kidney, lung, liver, and bone (improvement in the clinical manifestation). In addition, a change in the immunological parameters occurred (improvement in immunological parameters). The level of autoantibodies, including antinuclear antibody (ANA), and anti-double-stranded deoxyribonucleic acid antibodies (dsDNA Abs) reduced. A conversion of Th1/Th2 ratio (in favor of Th2), and Th17/Treg (in favor of Treg) was also detected. In spite of many advantages of MSC and HSC transplantations, including efficacy, safety, and increased survival rate of SLE patients, some complications, including recurrence of the disease, occurrence of infections, and secondary autoimmune diseases (SAD) were observed after transplantation that should be addressed in the next studies.

French protocol for the diagnosis and management of hematopoietic stem cell transplantation in autoimmune diseases

Hematopoietic stem cell transplantation (HSCT) for severe ADs was developed over the past 25years and is now validated by national and international medical societies for severe early systemic sclerosis (SSc) and relapsing-remitting multiple sclerosis (MS) and available as part of routine care in accredited center. HSCT is also recommended, with varying levels of evidence, as an alternative treatment for several ADs, when refractory to conventional therapy, including specific cases of connective tissue diseases or vasculitis, inflammatory neurological diseases, and more rarely severe refractory Crohn's disease. The aim of this document was to provide guidelines for the current indications, procedures and follow-up of HSCT in ADs. Patient safety considerations are central to guidance on patient selection and conditioning, always validated at the national MATHEC multidisciplinary team meeting (MDTM) based on recent (less than 3months) thorough patient evaluation. HSCT procedural aspects and follow-up are then carried out within appropriately experienced and Joint Accreditation Committee of International Society for Cellular Therapy and SFGM-TC accredited centres in close collaboration with the ADs specialist. These French recommendations were performed according to HAS/FAI2R standard operating procedures and coordinated by the Île-de-France MATHEC Reference Centre for Rare Systemic Autoimmune Diseases (CRMR MATHEC) within the Filière FAI2R and in association with the Filière MaRIH. The task force consisted of 3 patients and 64 clinical experts from various specialties and French centres. These data-derived and consensus-derived recommendations will help clinicians to propose HSCT for their severe ADs patients in an evidence-based way. These recommendations also give directions for future clinical research in this area. These recommendations will be updated according to newly emerging data. Of note, other cell therapies that have not yet been approved for clinical practice or are the subject of ongoing clinical research will not be addressed in this document.

Thrombopoietin receptor agonists for refractory thrombocytopenia in patients after autologous hematopoietic stem cell transplantation

OBJECTIVE

Autologous hematopoietic stem cell (ASC) transplantation (ASCT) is an effective treatment method for patients with hematological disorders and malignant diseases. The patient's ASCs are harvested prior to radiotherapy/chemotherapy, cryopreserved and then transfused back after the high-dose radiotherapy/chemotherapy conditioning treatment. Since some patients develop thrombocytopenia after receiving ASCT, it is difficult for them to bear simultaneously the management of their original disease and thrombocytopenia. The present study aimed to evaluate the efficacy and safety of thrombocytopenia therapy with thrombopoietin receptor agonists (TPORAs) after ASCT.

METHODS

We retrospectively analyzed the clinical safety and efficacy of TPORA treatment for the enrolled 20 patients who developed thrombocytopenia after ASCT. The measured parameters were prolonged isolated thrombocytopenia (PIT), secondary failure of platelet recovery (SFPR) and other calculated response index. Patients with platelet count (PC) ≤ 50×109/L were treated with TPORA, namely with either eltrombopag (Elt), hetrombopag (Het), or avatrobopag (Ava).

RESULTS

The group of 20 patients, who received TPORA administration for their thrombocytopenia after ASCT, had a median age of 50 years (ranging between 17 and 60 years). The median administration time of TPORA application was 48 days (ranging from 7 to 451 days); an overall response rate (ORR) was 85% with no response in 15% of patients, while with complete response (CR) in 70% of patients and partial response (PR) in 15% of patients. The median platelet count was 19 × 109/L before TPORA treatment and increased to 87×109)/L after the treatment. The TPORA treatment was safe as only 4 patients (20%) displayed a mild transaminase elevation. No other reported side effects occurred, such as thrombosis, joint pain, diarrhea, and myelofibrosis. It was demonstrated that the short response time to TPORA treatment correlated to the fast platelet recovery, when the number of megakaryocytes in the bone marrow smear exceeded 35/4.5 cm2 under a low magnification of 100 times (p = 0.015).

CONCLUSION

TPORA therapy for thrombocytopenia occurring after the radiotherapy/ chemotherapy-conditioned ASCT was well tolerated and effective for platelets recovery.

Stem cells in treatment of crohn's disease: Recent advances and future directions

BACKGROUND AND AIM

Crohn's disease (CD) is an inflammatory bowel disease that can affect any part of the intestine. There is currently no recognized cure for CD because its cause is unknown. One of the modern approaches that have been suggested for the treatment of CD and other inflammatory-based disorders is cell therapy.

METHODS

Search terms were stem cell therapy, CD, adipose-derived stem cells, mesenchymal stem cells, and fistula. Of 302 related studies, we removed duplicate and irrelevant papers and identified the ones with proper information related to our scope of the research by reviewing all the abstracts and categorizing each study into the proper section.

RESULTS AND CONCLUSION

Nowadays, stem cell therapy is widely implied in treating CD. Although mesenchymal and adipose-derived tissue stem cells proved to be safe in treating Crohn's-associated fistula, there are still debates on an optimal protocol to use. Additionally, there is still a lack of evidence on the efficacy of stem cell therapy for intestinal involvement of CD. Future investigations should focus on preparing a standard protocol as well as luminal stem cell therapy in patients.

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-Based Therapies for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic, relapsing disease that severely affects patients' quality of life. The exact cause of IBD is uncertain, but current studies suggest that abnormal activation of the immune system, genetic susceptibility, and altered intestinal flora due to mucosal barrier defects may play an essential role in the pathogenesis of IBD. Unfortunately, IBD is currently difficult to be wholly cured. Thus, more treatment options are needed for different patients. Stem cell therapy, mainly including hematopoietic stem cell therapy and mesenchymal stem cell therapy, has shown the potential to improve the clinical disease activity of patients when conventional treatments are not effective. Stem cell therapy, an emerging therapy for IBD, can alleviate mucosal inflammation through mechanisms such as immunomodulation and colonization repair. Clinical studies have confirmed the effectiveness of stem cell transplantation in refractory IBD and the ability to maintain long-term remission in some patients. However, stem cell therapy is still in the research stage, and its safety and long-term efficacy remain to be further evaluated. This article reviews the upcoming stem cell transplantation methods for clinical application and the results of ongoing clinical trials to provide ideas for the clinical use of stem cell transplantation as a potential treatment for IBD.

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.

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.

[Autologous hematopoietic cells for severe autoimmune diseases: Guidelines of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) for immune monitoring and biobanking]

Autologous hematopoietic cell transplantation (AHCT) is a new treatment option for patients with severe autoimmune diseases (AD), based on the use of intensive or myeloablative chemotherapy to eradicate the pathogenic autoreactive immune cells and to allow the installation of a new and tolerant immune system during immune reconstitution process. Immune reconstitution analysis after AHCT is required for patients clinical follow-up and to further identify biological and immunological markers of the clinical response to develop individualized AHCT protocols. These MATHEC-SFGM-TC good clinical practice guidelines were developed by a multidisciplinary group of experts including members of the french reference center for stem Cell Therapy in Auto-immune Diseases (MATHEC), hematologists from the French speaking Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) and experts in immune monitoring and biobanking. The objectives are to provide practical recommandations for immune monitoring and biobanking of samples in patients with AD undergoing AHCT, for routine care purposes and investigational studies.

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.

Hematopoietic stem cell transplantation for autoimmune diseases in the time of COVID-19: EBMT guidelines and recommendations

Coronavirus disease-19 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), represents one of the biggest challenges of 21st century, threatening public health around the globe. Increasing age and presence of co-morbidities are reported risk factors for severe disease and mortality, along with autoimmune diseases (ADs) and immunosuppressive treatments such as haematopoietic stem cell transplantation (HSCT), which are also associated with adverse outcomes. We review the impact of the pandemic on specific groups of patients with neurological, rheumatological, and gastroenterological indications, along with the challenges delivering HSCT in adult and pediatric populations. Moving forward, we developed consensus-based guidelines and recommendations for best practice and quality of patient care in order to support clinicians, scientists, and their multidisciplinary teams, as well as patients and their carers. These guidelines aim to support national and international organizations related to autoimmune diseases and local clinical teams delivering HSCT. Areas of unmet need and future research questions are also highlighted. The waves of the COVID-19 pandemic are predicted to be followed by an "endemic" phase and therefore an ongoing risk within a "new normality". These recommendations reflect currently available evidence, coupled with expert opinion, and will be revised according to necessary modifications in practice.

Hematopoietic Stem Cell Transplantation for Autoimmune Disease

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

Allogeneic hematopoietic stem cell transplantation for Crohn disease complicated with myelodysplastic syndrome: A case report

RATIONALE

Myelodysplastic syndrome (MDS) can be complicated with Crohn disease (CD). Irritable bowel disease (IBD) associated with MDS has already been reported in the past; however, hematopoietic stem cell transplantation (HSCT) is rarely performed. Herein, we report a case of CD with MDS for HSCT.

PATIENT CONCERNS

A 41-year-old man was hospitalized due to abdominal pain and intermittent fever for 40 days. Two years later, he was readmitted due to abdominal pain and diarrhea with fever for 10 days.

DIAGNOSIS

Symptoms, laboratory examinations, and imaging findings of the patient were indicative of CD complicated with MDS.

INTERVENTIONS

An allogeneic HSCT was performed.

OUTCOMES

He died of severe lung infection 125 days post-transplantation.

LESSONS

The number of cases of CD combined with MDS remains insufficient, and no consensus opinions are available to date. Hence, HSCT is a very potential treatment method. Additional experiences are needed to determine its effectiveness.

Stem and Progenitor Cells in the Pathogenesis and Treatment of Digestive Diseases

The global epidemic of chronic degenerative diseases expands rapidly. The pathogenesis of these noncommunicable disorders revolves around innate immunity, microbiome, and stem cell alterations. Understanding the mechanisms behind stem cell biology and their regulatory pathways is a key to understanding the origin of human disease. Stem cells are involved in tissue and organ damage and regeneration. The evidence is mounting that not only eukaryotic cells but also gut microbiota may release extracellular microvesicles that are absorbed from the gut into the portal and systemic circulation. Linking the fields of stem cells, innate immunity and microbiome research opens up new avenues to develop novel diagnostic (e.g., biomarkers), therapeutic (e.g., microbiome modulation, stem cell-based medicines), and prognostic (personalized diets) tools. In this chapter, we present the short overview of various stem and progenitor cells of adult tissues circulating in peripheral blood and their role in the pathogenesis and treatment of digestive diseases. We also briefly discuss the role of host-stem cell-microbial interactions as a new frontier of research in gastroenterology.

Novel Peptide CM 7 Targeted c-Met with Antitumor Activity

Anomalous changes of the cell mesenchymal–epithelial transition factor (c-Met) receptor tyrosine kinase signaling pathway play an important role in the occurrence and development of human cancers, including gastric cancer. In this study, we designed and synthesized a novel peptide (CM 7) targeting the tyrosine kinase receptor c-Met, that can inhibit c-Met-mediated signaling in MKN-45 and U87 cells. Its affinity to human c-Met protein or c-Met-positive cells was determined, which showed specific binding to c-Met with high affinity. Its biological activities against MKN-45 c-Met-positive cells were evaluated in vitro and in vivo. As a result, peptide CM 7 exhibited moderate regulation of c-Met-mediated cell proliferation, migration, invasion, and scattering. The inhibitory effect of peptide CM 7 on tumor growth in vivo was investigated by establishing a xenograft mouse model using MKN-45 cells, and the growth inhibition rate of tumor masses for peptide CM 7 was 62%. Based on our data, CM 7 could be a promising therapeutic peptide for c-Met-dependent cancer patients.

Tolerance regeneration by T regulatory cells in autologous haematopoietic stem cell transplantation for autoimmune diseases

Autologous haematopoietic stem cell transplantation shows increasing promise as a therapeutic option for patients with treatment-refractory autoimmune disease, particularly systemic sclerosis and multiple sclerosis. However, this intensive chemotherapy-based procedure is not always possible due to potential treatment toxicities and comorbidities. The biological mechanisms of how this procedure induces long-term remission in autoimmune disease are increasingly understood. The focus of this review is on recent research findings on the role of CD4+ T regulatory cells (Tregs) in resetting the immune system leading to the eradication of the autoimmune disease after transplantation. Discovery of the precise mechanisms of this process will allow development of novel Treg-based therapies and thus avoid the need for intensive chemotherapy-based treatment for these autoimmune diseases in the future.

Autologous stem cell transplantation in refractory Crohn's disease - low intensity therapy evaluation (ASTIClite): study protocols for a multicentre, randomised controlled trial and observational follow up study

BACKGROUND

Intestinal inflammation in Crohn's disease (CD) is caused by mucosal immune system reactivity to luminal antigen and results in debilitating symptoms, reduced quality of life, impaired work productivity and significant health care costs. Not all patients respond to conventional and biologic therapies, with chronic inflammation ensuing. Although surgical resection may be required, disease frequently returns and surgery may not be an option, or may be declined. Case reports suggest potential benefit after haematopoietic stem cell transplant (HSCT) for patients with refractory CD. The ASTIC trial asked whether HSCT could cure CD. Few patients achieved the primary endpoint of clinical remission for 3 months, off all medication with no evidence of active disease, and there were a high number of adverse events (AEs) and serious adverse events (SAEs), including one patient death. However, beneficial effects were observed in some aspects of disease activity. The ASTIClite trial will investigate these potential benefits and safety using a lower intensity regimen than ASTIC.

METHODS

Ninety-nine participants will be recruited from secondary care IBD centres in the UK into a multicentre, randomised controlled trial (RCT, ASTIClite) and an observational follow-up, and randomised to autologous HSCT versus standard care (ratio 2:1). The primary endpoint is treatment success at week 48, defined as mucosal healing without surgery or death. Secondary endpoints relating to efficacy, safety and mechanistic analyses will be evaluated at week 8, 14, 24, 32, 40 and 48. Long-term safety of the low intensity HSCT regimen forms the primary endpoint for the EBMT follow-up study and will be assessed annually for 4-7 years.

DISCUSSION

ASTIClite will compare HSCTlite with standard care with respect to safety, efficacy and quality of life, and capture outcomes allowing findings to be generalised to current clinical practice in the UK. It will also provide significant mechanistic insights into the immunological consequences of HSCTlite and its impact on treatment outcomes. The observational follow-up will provide information, which is currently unavailable for this population.

TRIAL REGISTRATION

The ASTIClite RCT was registered on 31st October 2017 ( ISRCTN17160440 ) and the EBMT follow-up study on 19th January 2018 ( ISRCTN31981313 ).

Differences in Peripheral and Tissue Immune Cell Populations Following Haematopoietic Stem Cell Transplantation in Crohn's Disease Patients

BACKGROUND AND AIMS

Recent studies have shown the efficacy of autologous haematopoietic stem cell transplantation [HSCT] in severely refractory Crohn's disease [CD] patients. HSCT is thought to eliminate auto-reactive cells; however, no specific studies of immune reconstitution in CD patients are available.

METHODS

We followed a group of CD patients [n = 18] receiving autologous HSCT, with 50% of them achieving endoscopic drug-free remission. To elucidate the mechanisms driving efficacy, we monitored changes after HSCT in blood and intestine immune-cell composition. CD patients [n = 22] receiving anti-tumour necrosis factor [TNF]-α were included for comparison.

RESULTS

Severe immune ablation followed by HSCT induced dramatic changes in both peripheral blood T and B cells in all patients regardless of the efficacy of the treatment. Endoscopic remission at week 52 following HSCT was associated with significant intestinal transcriptional changes. A comparison of the remission signature with that of anti-TNFα identified both common and unique genes in the HSCT-induced response. Based on deconvolution analysis of intestinal biopsy transcriptome data, we show that response to HSCT, but not to anti-TNFα, is associated with an expansion of naïve B-cells, as seen in blood, and a decrease in the memory resting T-cell content. As expected, endoscopic remission, in response to both HSCT and anti-TNFα, led to a significant reduction in intestinal neutrophil and M1 macrophage content.

CONCLUSIONS

Peripheral blood immune remodelling after HSCT does not predict efficacy. In contrast, a profound intestinal T-cell depletion that is maintained long after transplant is associated with mucosal healing following HSCT, but not anti-TNFα.

Autologous Hematopoietic Stem Cell Transplantation for Autoimmune Diseases: From Mechanistic Insights to Biomarkers

Phase I/II clinical trials of autologous hematopoietic stem cell transplantation (AHSCT) have led to increased safety and efficacy of this therapy for severe and refractory autoimmune diseases (AD). Recent phase III randomized studies have demonstrated that AHSCT induces long-term disease remission in most patients without any further immunosuppression, with superior efficacy when compared to conventional treatments. Immune monitoring studies have revealed the regeneration of a self-tolerant T and B cell repertoire, enhancement of immune regulatory mechanisms, and changes toward an anti-inflammatory milieu in patients that are responsive to AHSCT. However, some patients reactivate the disease after transplantation due to reasons not yet completely understood. This scenario emphasizes that additional specific immunological interventions are still required to improve or sustain therapeutic efficacy of AHSCT in patients with AD. Here, we critically review the current knowledge about the operating immune mechanisms or established mechanistic biomarkers of AHSCT for AD. In addition, we suggest recommendations for future immune monitoring studies and biobanking to allow discovery and development of biomarkers. In our view, AHSCT for AD has entered a new era and researchers of this field should work to identify robust predictive, prognostic, treatment-response biomarkers and to establish new guidelines for immune monitoring studies and combined therapeutic interventions to further improve the AHSCT protocols and their therapeutic efficacy.

Autologous haematopoietic stem cell transplantation (aHSCT) for severe resistant autoimmune and inflammatory diseases - a guide for the generalist

Autologous haematopoietic stem cell transplantation (aHSCT) is commonly used for the treatment of haematological cancers, but is increasingly used in the treatment of patients severely affected by autoimmune diseases (ADs). In fact, ADs have become the fastest growing indication for aHSCT. A wide range of diseases have been treated, but the field has focused on three areas: multiple sclerosis, diffuse cutaneous systemic sclerosis and Crohn's disease, where there are populations of patients for whom disease control remains unsatisfactory despite the advent of biological and targeted small molecule therapies. Scientific studies of immune reconstitution have provided support for a 'rebooting' of the immune system through a re-diversification of naive and regulatory immune effector cells. In addition, there may be health economic benefits from a single one-off procedure. Even so, the treatment with aHSCT is intensive with a range of toxicities and risks which, despite being routine to transplant haematologists, are less familiar to disease specialists. Close collaboration between transplant haematologists and relevant disease specialists in patient selection, clinical management and follow-up is mandatory. Ideally, patients should be treated on a clinical trial if available.

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

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