A Phase IB/IIA study of allogeneic bone marrow derived mesenchymal stem cells for the treatment of refractory ileal anal anastomosis and peripouch fistulas in the setting of Crohn's disease of the pouch

Exploiting regulatory T cells (Tregs): Cutting-edge therapy for autoimmune diseases

Regulatory T cells (Tregs) are a specialized subset of suppressive T cells that are essential for maintaining self-tolerance, regulating effector T cells, managing microbial infections, preventing tumors, allergies, and autoimmune disorders, and facilitating allograft transplantation. Disruptions in Treg function or abundance contribute to an imbalance between pathogenic and protective immune cells in autoimmune diseases. Recently, one promising treatment strategy to restore immune balance involves the selective expansion or manipulation of Tregs using low-dose IL-2 therapy, adoptive Treg cell transfer, and chimeric antigen receptor (CAR)-Treg approaches. Tregs have been shown in an increasing number of research studies to prevent or even treat a variety of disorders, such as tumors, autoimmune and allergic diseases, transplant rejection, and graft-versus-host disease. A thorough comprehension of Treg function is anticipated to provide clear prospects for effective Treg immunotherapy in the treatment of a wide range of diseases. This review provides an overview of Tregs biology, including their functions, suppressive mechanisms, phenotypic markers, as well as their involvement in disease settings. Furthermore, we discuss the therapeutic potential of different Treg subpopulations and their translational applications in the treatment of autoimmune diseases.

Clinical Progress in Mesenchymal Stem Cell Therapy: A Focus on Rheumatic Diseases

BACKGROUND

Rheumatic diseases are chronic immune-mediated disorders affecting multiple organ systems and significantly impairing patients' quality of life. Current treatments primarily provide symptomatic relief without offering a cure. Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic option due to their ability to differentiate into various cell types and their immunomodulatory, anti-inflammatory, and regenerative properties. This review aims to summarize the clinical progress of MSC therapy in rheumatic diseases, highlight key findings from preclinical and clinical studies, and discuss challenges and future directions.

METHODOLOGY

A comprehensive review of preclinical and clinical studies on MSC therapy in rheumatic diseases, including systemic lupus erythematosus, rheumatoid arthritis, ankylosing spondylitis, osteoarthritis, osteoporosis, Sjögren's syndrome, Crohn's disease, fibromyalgia, systemic sclerosis, dermatomyositis, and polymyositis, was conducted. Emerging strategies to enhance MSC efficacy and overcome current limitations were also analyzed.

RESULTS AND DISCUSSION

Evidence from preclinical and clinical studies suggests that MSC therapy can reduce inflammation, modulate immune responses, and promote tissue repair in various rheumatic diseases. Clinical trials have demonstrated potential benefits, including symptom relief and disease progression delay. However, challenges such as variability in treatment response, optimal cell source and dosing, long-term safety concerns, and regulatory hurdles remain significant barriers to clinical translation. Standardized protocols and further research are required to optimize MSC application.

CONCLUSION

MSC therapy holds promise for managing rheumatic diseases, offering potential disease-modifying effects beyond conventional treatments. However, large-scale, well-controlled clinical trials are essential to establish efficacy, safety, and long-term therapeutic potential. Addressing current limitations through optimized treatment protocols and regulatory frameworks will be key to its successful integration into clinical practice.

Emerging Technologies in Inflammatory Bowel Disease: A Minireview on Future Treatment Modalities

Inflammatory bowel disease (IBD) can present as either Crohn's disease or ulcerative colitis. Both phenotypes are inflammatory conditions of the gastrointestinal tract. Despite scientific advances, the overall incidence and morbidity of IBD continues to increase worldwide. Fortunately, we continue to develop novel therapies, in hopes of providing safer, more effective treatment options. Such therapies include cell therapy, exosome therapy, hyperbaric oxygen therapy, and central nerve stimulation. The aim of this review is to briefly highlight each of these novel therapeutic interventions as they relate to the treatment of IBD.

How to Approach the Difficult Perineum in Crohn's Disease

Crohn's disease (CD) is a chronic, inflammatory bowel disease with a wide range of presentations, including perianal disease. Presentation is variable, ranging from skin tags to complex fistulas, strictures, and nonhealing wounds. Symptoms of perianal CD can be devastating and may impact quality of life. Optimal management requires coordinated medical and surgical therapy. When possible, conservative treatment of perianal disease should be attempted. However, surgical treatment is often required, and some patients may ultimately require total proctocolectomy with permanent diversion due to the severity of disease. Even with close attention and treatment, disease can be recurrent, and complications of treatment are sometimes worse than the initial presentation. Novel treatments, including use of mesenchymal stem cells and autologous fat grafting, hold some promise, but are not yet widely available. Thorough knowledge of treatment options, careful patient selection, coordination between medical and surgical providers, and setting realistic expectations are important in the successful treatment of difficult perineal CD.

Crohn's-like Ileal Pouch Illness and Ileal Pouch Salvage Strategies

De novo Crohn's disease (CD) of the pouch or Crohn's-like Ileal Pouch Illness (CLIPI) is an increasingly common occurrence in an ever-growing ileal pouch population. Although currently undetermined if a subset of classic CD or a completely new entity, it primarily affects the prepouch afferent limb, pouch, and rectal cuff. Symptoms can mimic other more common disorders, such as pouchitis, and requires a thorough workup, including pouchoscopy with biopsy and often cross-sectional imaging, for the diagnosis to be made. There is an increased risk of long-term pouch failure in this population. Treatment is typically dependent upon the disease phenotype with surgical management considered in a step-up fashion. Medical management is primarily performed with "biologics," such as antitumor necrosis factor agents, although data are limited due to the lack of randomized controlled trials. Surgical management for CLIPI can include endoscopic, anorectal, and abdominal approaches to assist as "pouch-salvage strategies." The performance of advanced pouch-salvage techniques in the CLIPI population requires careful patient selection and should preferably be performed at high-volume pouch centers.

Perianal Fistulizing Crohn's Disease: Outcomes of Surgical Repairs and Current State of Stem Cell-Based Therapies

Perianal fistulizing Crohn's disease is one of the most disabling phenotypes of Crohn's disease, due to the severe impairment in quality of life including social and personal wellbeing. A multimodal approach with patient-tailored care is the key to optimal management of this condition. Medical therapy is needed to optimize the luminal disease, and surgical intervention is required to control any associated perianal sepsis and attempt palliative or definitive fistula repair. While several medical and surgical options are available, the majority of patients continue to have symptomatic disease. Fortunately, this continues to drive novel innovations which are revolutionizing the treatment and outcomes of perianal fistulizing Crohn's disease. However, there continues to be a need for randomized trials and consistent metrics utilized for classification and treatment outcomes in order to accurately describe optimal treatment outcomes.

Trained mesenchymal stromal cell-based therapy HXB-319 for treating diffuse alveolar hemorrhage in a pristane-induced murine model

INTRODUCTION

Mesenchymal stromal cells (MSCs) can modulate immune responses and suppress inflammation in autoimmune diseases. Although their safety has been established in clinical trials, the efficacy of MSCs is inconsistent due to variability in potency among different preparations and limited specificity in targeting mechanisms driving autoimmune diseases.

METHODS

We utilized high-dimensional design of experiments methodology to identify factor combinations that modulate gene expression by MSCs to mitigate inflammation. This led to a novel MSC-based cell therapy, HXB-319. Its anti-inflammatory properties were validated in vitro by flow cytometry, RT-PCR, and mass spectrophotometry. To evaluate in vivo efficacy, we treated a diffuse alveolar hemorrhage (DAH) mouse model (C57Bl/6). Seven days post-DAH induction with pristane, mice received either MSCs or HXB-319 (2X106 cells, IP). On day 14, peritoneal lavage fluid (PLF) and lung tissue were collected for flow cytometry, histopathological examination, and mRNA.

RESULTS

HXB-319 increased gene expression levels of anti-inflammatory, angiogenic, and anti-fibrotic factors (eg, TSG-6, VEGF, and HGF). KEGG pathway analysis confirmed significant activation of relevant anti-inflammatory, angiogenic, and anti-fibrotic proteins, corroborating RT-PCR results. In the DAH model, HXB-319 significantly reduced lung inflammation and alveolar hemorrhage compared to MSC-treated and untreated DAH mice. HXB-319 treatment also significantly decreased neutrophils, plasmacytoid dendritic cells, and RORγT cells, increased FoxP3+ cells in PLF, and reversed alterations in mRNA encoding IL-6, IL-10, and TSG-6 in lung tissue compared to DAH mice.

CONCLUSION

HXB-319 effectively controls inflammation and prevents tissue damage in pristine-induced DAH, highlighting its therapeutic potential for autoimmune inflammatory diseases.

Optimization of transplantation methods using isolated mesenchymal stem/stromal cells: clinical trials of inflammatory bowel diseases as an example

Mesenchymal stem/stromal cells (MSCs) are distributed in various tissues and are used in clinical applications as a source of transplanted cells because of their easy harvestability. Although MSCs express numerous cell-surface antigens, single-cell analyses have revealed a highly heterogeneous cell population depending on the original tissue and donor conditions, including age and interindividual differences. This heterogeneity leads to differences in their functions, such as multipotency and immunomodulatory effects, making it challenging to effectively treat targeted diseases. The therapeutic efficacy of MSCs is controversial and depends on the implantation site. Thus, there is no established recipe for the transplantation of MSCs (including the type of disease, type of origin, method of cell culture, form of transplanted cells, and site of delivery). Our recent preclinical study identified appropriate MSCs and their suitable transplantation routes in a mouse model of inflammatory bowel disease (IBD). Three-dimensional (3D) cultures of MSCs have been demonstrated to enhance their properties and sustain engraftment at the lesion site. In this note, we explore the methods of MSC transplantation for treating IBDs, especially Crohn's disease, from clinical trials published over the past decade. Given the functional changes in MSCs in 3D culture, we also investigate the clinical trials using 3D constructs of MSCs and explore suitable diseases that might benefit from this approach. Furthermore, we discuss the advantages of the prospective isolation of MSCs in terms of interindividual variability. This note highlights the need to define the method of MSC transplantation, including interindividual variability, the culture period, and the transplantation route.

A Comparative Analysis of the Advances in Stem Cell Therapy in Plastic Surgery: A Systematic Review of Current Applications and Future Directions

Stem cell (SC) therapy is revolutionizing the field of plastic surgery by harnessing the regenerative abilities of SCs derived from adipose tissue and bone marrow to boost tissue repair and enhance aesthetic outcomes. This groundbreaking method enhances results in procedures such as fat grafting, facial rejuvenation, and wound healing. As studies advance, SC therapy shows potential for more sophisticated uses in both reconstructive and cosmetic surgery. The objective of this review is to comprehensively examine the advances in SC therapy within the field of plastic surgery, highlighting its current applications and exploring future directions. The systematic review was conducted on SC therapy in plastic surgery adhering to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and specific search criteria. This systematic review highlights these main outcomes, and SC therapy in plastic surgery enhances tissue repair and aesthetic outcomes by utilizing mesenchymal SCs such as adipose-derived SCs (ADSCs) and bone marrow-derived SCs (BMSCs), with platelet-rich plasma (PRP) providing additional support. Techniques such as scaffolds and cellular reprogramming are employed to guide SC growth, enabling tailored tissue engineering for complex regenerative procedures. This innovative approach accelerates healing, reduces scarring in reconstructive surgeries, improves skin texture, and ensures the natural integration of treated areas, ultimately yielding enhanced aesthetic results and transforming facial rejuvenation processes. SC therapy in plastic surgery holds great promise, but challenges such as protocol standardization, cost, and regulations still need to be addressed. SC therapy is leading innovative advancements in plastic surgery, offering superior outcomes and improved quality of life for patients. Interestingly, the future of plastic surgery is focused on integrating SC therapy for personalized and transformative treatments. Furthermore, interdisciplinary collaboration among bioengineers, clinicians, and regulatory bodies is essential for overcoming challenges and advancing SC research into clinical practice.

Long-term outcomes of fistula-tract laser closure for complex perianal fistulizing Crohn's disease

BACKGROUND

Fistula-tract laser closure (FiLaC™) has shown promising outcomes in perianal fistulizing Crohn's disease (pfCD). However, most studies assessed a mixed cohort encompassing pfCD and cryptoglandular fistulas during a short follow-up period. This study aimed to evaluate the long-term treatment outcomes of FiLaC™ in patients with complex pfCD.

METHODS

Data from patients with complex pfCD who underwent FiLaC™ during deep remission of Crohn's disease between January 2019 and December 2020 were retrospectively analyzed. Patient demographics, surgery history, and medication strategy were registered before surgery. Follow-ups were scheduled at 1, 2, and 3 months after FiLaC™, and at 2-month intervals thereafter. The primary endpoint was clinic healing, while clinic remission/unhealed/recurrence were classified as unhealed. Additionally, adverse events and Wexner fecal incontinence score were documented.

RESULTS

Forty-nine patients (40 men and 9 women) with a median age of 26.0 (19.0-35.5) years were included with a median follow-up of 50.0 (39.5-54.0) months. Of these, 31 (63.3%) patients achieved fistula healing, 3 (6.1%) experienced improvement, 3 (6.1%) remained unhealed, and 12 (24.5%) experienced recurrence. Montreal A category was lower in the healed group (P < 0.001). No major complications, such as bleeding or fecal or urinary incontinence, were observed, and pain was transient. The Wexner incontinence score decreased significantly at the last available follow-up, indicating an intact postoperative continence function (P = 0.014). PCDAI scores were significantly higher in the unhealed group (P = 0.041).

CONCLUSION

FiLaC™ is an efficient and safe sphincter-saving procedure for patients with complex pfCD.

Stem Cells and Stem Cell-Derived Factors for the Treatment of Inflammatory Bowel Disease with a Particular Focus on Perianal Fistulizing Disease: A Minireview on Future Perspectives

Inflammatory bowel disease remains a difficult disease to effectively treat, especially fistulizing Crohn's disease. Perianal fistulas in the setting of Crohn's disease remain an area of unmet need with significant morbidity in this patient population. Up to one third of Crohn's patients will have perianal fistulizing disease and current medical and surgical interventions are of limited efficacy. Thus, most patients experience significant morbidity, narcotic use, and loss of employment and end up with multiple surgical interventions. Mesenchymal stem cells (MSCs) have shown efficacy in phase 3 clinical trials, but considerable infrastructure challenges make MSCs limited with regard to scalability in clinical practice. Extracellular vesicles, being derived from MSCs and capturing the secretome functionality of MSCs, offer similar physiological utility regarding mechanism, while also providing an off the shelf regenerative medicine product that could be widely used in daily clinical practice.

Radiographic Evaluation of Ileal Pouch Disorders: A Systematic Review

BACKGROUND

Radiographic imaging of the abdomen and pelvis plays an important role in the diagnosis and management of ileal pouch disorders with modalities including CT, MRI, contrasted pouchography, and defecography.

OBJECTIVES

To perform a systematic review of the literature and describe applications of cross-sectional imaging, pouchography, defecography, and ultrasonography.

DATA SOURCES

PubMed, Google Scholar, and Cochrane database.

STUDY SELECTION

Relevant articles on endoscopy in ileal pouches published between January 2003 and June 2023 in English were included on the basis of Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

INTERVENTION

Main abdominal and pelvic imaging modalities and their applications in the diagnosis of ileal pouch disorders were included.

MAIN OUTCOME MEASURES

Accuracy in characterization of ileal pouch disorders.

RESULTS

CT is the test of choice for the evaluation of acute anastomotic leaks, perforation, and abscess(es). MRI of the pelvis is suitable for the assessment of chronic anastomotic leaks and their associated fistulas and sinus tracts, as well as for the penetrating phenotype of Crohn's disease of the pouch. CT enterography and magnetic resonance enterography are useful in assessing intraluminal, intramural, and extraluminal disease processes of the pouch and prepouch ileum. Water-soluble contrast pouchography is particularly useful for evaluating acute or chronic anastomotic leaks and outlines the shape and configuration of the pouch. Defecography is the key modality to evaluate structural and functional pouch inlet and outlet obstructions. Ultrasonography can be performed to assess the pouch in experienced IBD centers.

LIMITATIONS

This is a qualitative, not quantitative, review of mainly case series and case reports.

CONCLUSIONS

Abdominopelvic imaging, along with clinical and endoscopic evaluation, is imperative for accurately assessing structural, inflammatory, functional, and neoplastic disorders. See video from symposium .

Therapeutic Prospects of Mesenchymal Stem Cell and Their Derived Exosomes in the Regulation of the Gut Microbiota in Inflammatory Bowel Disease

Mesenchymal stem cells (MSCs) have shown great potential in the treatment of several inflammatory diseases due to their immunomodulatory ability, which is mediated by exosomes secreted by MSCs (MSC-Exs). The incidence of inflammatory bowel disease (IBD) is increasing globally, but there is currently no long-term effective treatment. As an emerging therapy, MSC-Exs have proven to be effective in alleviating IBD experimentally, and the specific mechanism continues to be explored. The gut microbiota plays an important role in the occurrence and development of IBD, and MSCs and MSC-Exs can effectively regulate gut microbiota in animal models of IBD, but the mechanism involved and whether the outcome can relieve the characteristic dysbiosis necessary to alleviate IBD still needs to be studied. This review provides current evidence on the effective modulation of the gut microbiota by MSC-Exs, offering a basis for further research on the pathogenic mechanism of IBD and MSC-Ex treatments through the improvement of gut microbiota.

Patient engagement and satisfaction with early phase cell therapy clinical trials at a tertiary inflammatory bowel disease center

Several clinical trials are underway investigating cell and gene therapy, and while these trials are meant to significantly impact patient care, they rely on patient engagement and participation. Unfortunately, clinical trials generally require extensive commitment by subjects. While several studies are using validated surveys to measure patient-reported outcomes, there is a lack of characterization of the patient experience as a subject in these trials. As such, we surveyed mesenchymal stromal cell (MSC) trial participants to understand their perspective. We found that there exists a reliance on one's gastroenterologist and colorectal surgeons for trial introduction and that time and cost were the main barriers to participation. Overall, participants demonstrated high satisfaction with MSC trial participation, but future protocols could incorporate increased use of virtual appointments to optimize patient experience.

Treatment effect of ex vivo expanded allogeneic bone marrow-derived mesenchymal stem cells for the treatment of fistulizing Crohn's disease are durable at 12 months

BACKGROUND

Mesenchymal stem cells have been administered via direct injection to treat perianal Crohn's fistulizing disease. We herein sought to determine the safety and durability of treatment response to 12 months with 3 individual phase IB/IIA clinical trials of mesenchymal stem cells for refractory perianal, rectovaginal, and ileal pouch fistulas in the setting of Crohn disease.

METHODS

Three phase IB/IIA randomized placebo-controlled single-blinded clinical trials were performed for (1) perianal fistulas, (2) rectovaginal fistula, and (3) ileal pouch in situ with anovaginal and/or perianal fistulas. Bone marrow-derived mesenchymal stem cells (75 million in 7.5 mL) were injected at the time of exam under anesthesia on day 0 and month 3. Outcome measures were adverse events and combined clinical and pelvic magnetic resonance imaging healing at month 6 and month 12.

RESULTS

Across all 3 trials, 64 patients were enrolled; 49 were treatment and 15 were control. At 6 months, combined clinical and radiographic healing was achieved in 83.3%, 33.3%, and 30.8% of the perianal, rectovaginal, and pouch fistula treatment cohorts, respectively. At 12 months, the treatment response was durable, with 67.7% of perianal, 37.5% of rectovaginal, and 46.2% of peripouch fistulas maintaining complete clinical and radiographic healing. Two patients in the perianal fistula control cohort achieved combined clinical and radiographic healing at 12 months, whereas 0% of rectovaginal and pouch control patients healed.

CONCLUSION

Bone marrow-derived mesenchymal stem cells offer a safe and effective alternative treatment approach for severe perianal, rectovaginal, and peripouch fistulizing Crohn's disease. Treatment results are durable at 12 months.

Efficacy and safety of stem cell therapy for Crohn's disease: a meta-analysis of randomized controlled trials

PURPOSE

Small-scale clinical trials have provided evidence suggesting the effectiveness of stem-cell therapy (SCT) for patients diagnosed with Crohn's disease (CD). The objective of the research was to systematically assess the effectiveness and safety of SCT for individuals diagnosed with CD through a comprehensive review and meta-analysis.

METHODS

A search was conducted in Medline (PubMed), CENTER (Cochrane Library), and Embase (Ovid) to find randomized controlled trials (RCTs) that assessed the impact of SCT on the occurrence of clinical remission (CR) and severe adverse events (SAE) among patients diagnosed with CD. The Cochrane Q test and estimation of I2 were used to assess heterogeneity among studies. After incorporating heterogeneity, a random-effects model was employed for data pooling.

RESULTS

Overall, 12 RCTs involving 632 adult patients with medically refractory CD or CD-related fistula were included. In comparison with placebo or no treatment, SCT showed a greater likelihood of CR (odds ratio [OR] 2.08, 95% CI 1.39-3.12, p < 0.001) without any notable heterogeneity (I2 = 0%). Consistent results were observed in subgroup analyses based on study design, patient diagnosis, source and type of stem cells, and follow-up durations, with all p-values for subgroup analyses being greater than 0.05. The occurrence of SAE was similar among patients assigned to SCT and the placebo/no treatment cohorts (OR 0.70, 95% CI 0.37-1.33, p = 0.28; I2 = 0%).

CONCLUSIONS

For patients with medically refractory CD or CD-related fistula, SCT may be an alternatively effective and safe treatment.

Current state of stem cell research in non-human primates: an overview

The remarkable similarity between non-human primates (NHPs) and humans establishes them as essential models for understanding human biology and diseases, as well as for developing novel therapeutic strategies, thereby providing more comprehensive reference data for clinical treatment. Pluripotent stem cells such as embryonic stem cells and induced pluripotent stem cells provide unprecedented opportunities for cell therapies against intractable diseases and injuries. As continue to harness the potential of these biotechnological therapies, NHPs are increasingly being employed in preclinical trials, serving as a pivotal tool to evaluate the safety and efficacy of these interventions. Here, we review the recent advancements in the fundamental research of stem cells and the progress made in studies involving NHPs.