Long-term Efficacy and Safety of Stem Cell Therapy (Cx601) for Complex Perianal Fistulas in Patients With Crohn's Disease

Perianal Fistulizing Crohn's Disease: Utilizing the TOpClass Classification in Clinical Practice to Provide Targeted Individualized Care

BACKGROUND & AIMS

Perianal fistulation is a challenging phenotype of Crohn's disease, with significant impact on quality of life. Historically, fistulae have been classified anatomically in relation to the sphincter complex, and management guidelines have been generalized, with lack of attention to the clinical heterogenicity seen. The recent 'TOpClass classification system' for perianal fistulizing Crohn's disease (PFCD) addresses this issue, and classifies patients into defined groups, which provide a focus for fistula management that aligns with disease characteristics and patient goals. In this article, we discuss the clinical applicability of the TOpClass model and provide direction on its use in clinical practice.

METHODS

An international group of perianal clinicians participated in an expert consensus to define how the TOpClass system can be incorporated into real-life practice. This included gastroenterologists, inflammatory bowel disease surgeons, and radiologists specialized in PFCD. The process was informed by the multi-disciplinary team management of 8 high-volume fistula centres in North America, Europe, and Australia.

RESULTS

The process produced position statements to accompany the classification system and guide PFCD management. The statements range from the management of patients with quiescent perianal disease to those with severe PFCD requiring diverting-ostomy and/or proctectomy. The optimization of medical therapies, as well as the use of surgery, in fistula closure and symptom management is explored across each classification group.

CONCLUSION

This article provides an overview of the system's use in clinical practice. It aims to enable clinicians to have a pragmatic and patient goal-centered approach to medical and surgical management options for individual patients with PFCD.

Systematic review and meta-analysis of the efficacy and safety of stem cell treatment of anal fistulas

BACKGROUND

Since anal fistulas can be challenging to treat; numerous innovative treatments have been proposed, including stem cell therapy. This systematic review aimed to assess pooled rates of fistula healing and adverse events associated with stem cell treatment.

METHODS

In this PRISMA-compliant systematic review we searched PubMed and Scopus for observational and randomized studies reporting outcomes of stem cell treatment for anal fistulas. The main outcome measures were successful healing and adverse effects of stem cell therapy.

RESULTS

In total, 43 studies incorporating 1160 patients (53.6% male) were included. Underlying fistula etiologies were Crohn's disease (30 studies) and cryptoglandular disease (12 studies). The main origin of stem cells was from adipose tissue (34 studies) or bone marrow (6 studies). The median follow-up duration was 12 months. The combined overall pooled healing rate was 58.1% (95% confidence interval (CI) 51.5-64.7%). The pooled healing rate for Crohn's fistulas was 60.4% (95% CI 54.7-66.2%) with adipose-derived stem cells and 63.6% (95% CI 49.4-77.7%) with bone-marrow-derived cells. The pooled healing rate for cryptoglandular fistulas was 53.8% (95% CI 35.5-72.2%) with adipose-derived stem cells. The pooled complication rate was 37.3% (95% CI 27.1-47.5%). Stem cells were associated with higher odds of anal fistula healing (odds ratio (OR): 1.81, p = 0.003) and similar odds of complications (OR: 1, p = 0.986) compared with controls.

CONCLUSIONS

Stem cell treatment of anal fistulas was associated with promising results. The healing rate in Crohn's anal fistulas was higher than in cryptoglandular fistulas. Bone-marrow-derived stem cells were associated with marginally better outcomes than were adipose-derived cells. This finding suggests that the autoimmune inflammatory etiology of Crohn's disease may respond better to autologous myoblasts than does the infectious etiology of cryptoglandular fistulas.

Consecutive intrabronchial administration of Wharton's jelly-derived mesenchymal stromal cells in ECMO-supported pediatric patients with end-stage interstitial lung disease: a safety and feasibility study (CIBA method)

BACKGROUND

Patients ineligible for lung transplant with end-stage Interstitial Lung Disease (ILD) on Extra-Corporeal Membrane Oxygenation (ECMO) face an appalling prognosis with limited therapeutic options. Due to the beneficial effect of Mesenchymal Stromal Cells (MSC) on inflammatory, immunological and infectious diseases, cell therapy has been proposed as an option, but administration is hampered by the ECMO.

METHODS

Cryopreserved Wharton-jelly derived MSC (WJ-MSC) were conveniently diluted and directly applied consecutively on each lobule (5,1 ml = 107 cells) at a continuous slow rate infused over one hour via flexible bronchoscopy (Consecutive IntraBronchial Administration method, CIBA method).

RESULTS

Intrabronchial administration of MSC to a patient on ECMO was well tolerated by the patient even though it did not reverse the patient's ILD. This manuscript presents preliminary evidence from ongoing clinical trials program on Cell Therapy of Inflammatory, Immune and Infectious Diseases and, to our knowledge, is the first report of intrabronchial administration of MSC in a paediatric ECMO patient with ILD. Even more, MSC administered by this method do not reach the systemic circulation and do get blocked on ECMO membrane.

CONCLUSIONS

Direct intrabronchial administration of MSC in a patient on ECMO is feasible and safe, and may be a new avenue to be assayed in ECMO patients with inflammatory, immunological and infectious diseases of the lung.

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.

Darvadstrocel for complex perianal fistulas in Crohn's disease: A systematic review and meta-analysis

BACKGROUND

Local injection of darvadstrocel, a suspension of expanded adipose-derived allogenic mesenchymal stem cells, has been used for treatment-refractory perianal fistulas in Crohn's disease (CD).

OBJECTIVE

This study aimed to investigate efficacy and safety of darvadstrocel for complex perianal fistulas in CD.

METHODS

A systematic search was conducted through April 2024 in relevant databases for observational studies evaluating darvadstrocel. A random-effects meta-analysis model was used to calculate the pooled effect sizes (proportions or incidence rates [IRs]) with 95% confidence intervals (CIs) of effectiveness and safety outcomes. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Tool. The I2 value assessed heterogeneity. Sensitivity and subgroup analyses were also conducted.

RESULTS

Twelve studies were included with 595 patients. The pooled rate of patients achieving clinical remission, defined as fistula healing, was 68.1% at month 6 (95% CI 63.4-72.7) and 77.2% (95% CI 70.1-83.8) at month 12. Combined remission, defined as clinical remission and absence of collections >2 cm confirmed by magnetic resonance imaging, was reported in 60.6% and in 69.7% of patients at months 6 and 12, respectively. The rate of patients with treatment failure, defined as no clinical remission at the last follow-up (mean 18.7 months; SD 9.9), was 34.5%. Failure rate was independent of follow-up time (p = 0.85). For effectiveness outcomes, between-study heterogeneity was negligible. Subgroup analysis indicated that none of the covariates modified the treatment effect. Pooled IRs per 100 patient-years of adverse events (AE), serious AEs, perianal abscesses, and reoperations were 19.6, 3.2, 16.9 and 7.1, respectively.

CONCLUSION

Evidence from observational studies supports the efficacy and safety of darvadstrocel for complex perianal fistulas in CD. Studies have reported high fistula healing rates that can be sustained long-term in most patients, with negligible between-study heterogeneity, as well as a favorable safety profile.

Sequential Applications of Adipose Tissue-derived Stem Cells Enhance Healing in Complex Wounds: Experimental Model

Background

Complex wounds represent a challenge to global health, incurring significant healthcare costs and compromising patients' quality of life. Recently, research has investigated the potential of adipose tissue-derived stem cells (ASC) for therapeutic stem cells' immunomodulatory properties. This study aimed to evaluate the effect of sequential applications of ASC in an experimental model of a complex wound.

Methods

Thirty male Wistar rats were subjected to a complex wound model of enterocutaneous fistula. After 4 weeks, the rats were divided into 3 groups: control, 2 applications of culture medium, and 2 applications of 1 × 106 allogeneic ASC. The animals were euthanized and analyzed 4 weeks after the first application regarding the macroscopic reduction of the wound, histopathologic changes, and gene expression related to wound healing (Cd68, Il1rap, Il10, Mmp3, Mmp9, and Tnf).

Results

Animals treated with ASC showed a reduction in wound diameter of 68% compared with the control group (P = 0.002) and a reduction of 65% compared with the culture medium group (P = 0.011). The ASC group also showed a more than 100% increase in blood vessel count compared with the control group (P = 0.02). Gene expression analysis showed a decrease in the Mmp9 levels in the ASC group compared with the control group.

Conclusions

This study demonstrated that the treatment with ASC improves the healing of enterocutaneous fistula wounds.

Extracellular Vesicles Delivered by a Nanofiber-Hydrogel Composite Enhance Healing In Vivo in a Model of Crohn's Disease Perianal Fistula

Perianal fistulas represent a common, aggressive, and disabling complication of Crohn's disease (CD). Despite recent drug developments, novel surgical interventions as well as multidisciplinary treatment approaches, the outcome is dismal, with >50% therapy failure rates. Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) offer potential therapeutic benefits for treating fistulizing CD, due to the pro-regenerative paracrine signals. However, a significant obstacle to clinical translation of EV-based therapy is the rapid clearance and short half-life of EVs in vivo. Here, an injectable, biodegradable nanofiber-hydrogel composite (NHC) microgel matrix that serves as a carrier to deliver MSC-derived EVs to a rat model of CD perianal fistula (PAF) is reported. It is found that EV-loaded NHC (EV-NHC) yields the best fistula healing when compared to other treatment arms. The MRI assessment reveals that the EV-NHC reduces inflammation at the fistula site and promotes tissue healing. The enhanced therapeutic outcomes are contributed by extended local retention and sustained release of EVs by NHC. In addition, the EV-NHC effectively reduces inflammation at the fistula site and promotes tissue healing and regeneration via macrophage polarization and neo-vascularization. This EV-NHC platform provides an off-the-shelf solution that facilitates its clinical translation.

Mesenchymal Stromal Cell-Based Therapy: A Promising Approach for Autoimmune Diseases

Autoimmune diseases are characterized by immune dysregulation, resulting in aberrant reactivity of T cells and antibodies to self-antigens, leading to various patterns of inflammation and organ dysfunction. However, current therapeutic agents exhibit broad-spectrum activity and lack disease-specific selectivity, leading to enduring adverse effects, notably severe infections, and malignancies, and patients often fail to achieve the intended clinical goals. Mesenchymal stromal cells (MSCs) are multipotent stromal cells that can be easily derived from various tissues, such as adipose tissue, umbilical cords, Wharton's jelly, placenta, and dental tissues. MSCs offer advantages due to their immunomodulatory and anti-inflammatory abilities, low immunogenicity, and a high capacity for proliferation and multipotent differentiation, making them excellent candidates for cell-based treatment in autoimmune disorders. This review will cover preclinical studies and clinical trials involving MSCs in autoimmune diseases, as well as the primary challenges associated with the clinical application of MSC therapies and strategies for maximizing their therapeutic potential.

Injectable DAT-ALG Hydrogel Mitigates Senescence of Loaded DPMSCs and Boosts Healing of Perianal Fistulas in Crohn's Disease

Perianal fistulas (PAFs) are a severe complication of Crohn's disease that significantly impact patient prognosis and quality of life. While stem-cell-based strategies have been widely applied for PAF treatment, their efficacy remains limited. Our study introduces an injectable, temperature-controlled decellularized adipose tissue-alginate hydrogel loaded with dental pulp mesenchymal stem cells (DPMSCs) for in vivo fistula treatment. The experimental group demonstrated higher healing rates compared to surgical and DPMSCs groups, as evidenced by magnetic resonance imaging, multiplex immunohistochemical, and ELISA analyses. KEGG enrichment of differential genes suggested cellular senescence involvement in cell therapy efficacy, further confirmed by β-galactosidase staining and senescence markers (p21 and p53). Collectively, our research provides a novel therapy for PAFs and illuminates underlying mechanisms.

Mesenchymal stromal cell therapy: Progress to date and future outlook

In clinical trials, mesenchymal stromal/stem cells (MSCs) have consistently demonstrated safety. However, demonstration of efficacy has been inconsistent and many MSC trials have failed to meet their efficacy endpoint. This disappointing reality is reflected by the limited number MSC therapies approved by regulatory agencies, despite the large number of MSC trials registered on clinicaltrials.gov. Notably, there has been a recent approval of an MSC therapy for pediatric graft-vs.-host disease in the United States, marking the first MSC therapy approved by the U.S. Food and Drug Administration. This review provides a background of the history and potential therapeutic value of MSCs, an overview of MSC products with regulatory approval, and a summary of registered MSC trials. It concludes with a discussion on current and ongoing challenges and questions surrounding MSC therapy that remains to be resolved before becoming available for routine clinical use outside of clinical trials.

Evaluation of the Effectiveness and Safety of Mesenchymal Stem Cell Treatment in Fistulising Crohn's Disease: An International Real-Life Retrospective Multicentre Cohort Study

BACKGROUND

Perianal fistulas of Crohn's disease (CD) create a significant burden on patients' lives. However, the efficacy and safety of adipose-derived mesenchymal stem cell treatment are contradicting, and real-world evidence is lacking.

AIMS

To examine the usability of darvadstrocel therapy in managing perianal CD.

METHODS

We enrolled patients with CD and perianal fistulas in this retrospective multicenter study. The primary outcome was perianal clinical remission (defined as all treated fistulas closed) at weeks 26 and 52. Secondary outcomes were clinical response rates (≥ 1 fistulas closed), perianal activity (PDAI), patient satisfaction, and adverse events. Data were recorded at baseline and weeks 12, 26 and 52. Prediction of primary outcomes was performed by logistic regression.

RESULTS

Overall, among 223 patients (male/female ratio: 0.48), perianal clinical remission was achieved in 78.2% and 62.3% until weeks 26 and 52. Baseline PDAI score (OR 0.75), number of fistulas (OR 0.28) and the number of weeks after preparation for surgery (OR 0.98) were associated with treatment failure. The clinical response rates were 84.8% and 79.8% at weeks 26 and 52. Improvement of subjective perianal symptoms was achieved in 77.8% and 78.4% of patients, respectively. Adverse events occurred in 13.5% of patients; perianal abscesses and proctalgia were the most frequently reported.

CONCLUSION

Effectiveness data were higher than in clinical trials. The safety profile was reassuring, and patients' satisfaction was high. Appropriate patient selection, fistula preparation and expertise may help to achieve treatment success.

Patient and Healthcare Professional Perspectives on Crohn's Perianal Fistula Treatment: Results From a Discrete Choice Experiment

Background

Crohn's perianal fistulas (CPF) are difficult to manage and often require multiple interventions. This study aimed to assess the preferences of patients and healthcare professionals (HCPs) for attributes of CPF-related procedures/surgeries to better inform CPF management.

Methods

This US cross-sectional, observational study was conducted via a web-enabled questionnaire (October 2021-January 2022) among patients aged 21-89 years with a self-reported physician diagnosis of CPF (with or without CPF-related surgery experience) and HCPs (gastroenterologists and colorectal surgeons who managed ≥3 patients with CPF in the past 12 months). Patient and HCP preferences for CPF-related procedure/surgery attributes were assessed using a discrete choice experiment and stated preference methodology.

Results

In total, 100 patients and 137 HCPs were recruited. Benefits of therapy (symptom control and/or fistula closure) were rated as the most important CPF treatment attribute by both patients and HCPs influencing treatment decisions (mean relative importance 23.9 and 36.3, respectively). The mean relative importance of procedure invasiveness and postoperative discomfort was higher for patients (19.3 and 20.2, respectively) than for HCPs (14.3 and 11.0, respectively), whereas the mean relative importance of fecal incontinence was greater for HCPs than patients (25.0 vs. 19.3, respectively).

Conclusions

Patients and HCPs have different perspectives on the importance of specific CPF-related procedure/surgery attributes. The attributes identified as important to patients and HCPs in this study should be considered when managing patients with CPF and making treatment decisions.

Predictive modeling to evaluate long-term treatment effectiveness of darvadstrocel in patients with complex perianal fistulas in Crohn's disease

BACKGROUND

Current therapies for complex Crohn's perianal fistulas (CPF) have a limited ability to achieve long-term healing. Darvadstrocel (DVS) is an expanded allogeneic adipose-derived mesenchymal stem cell therapy that has demonstrated efficacy in treating complex CPF in clinical trials. There are, however, limited long-term comparative data with standard of care (SoC). The aim of this study was to combine clinical trial data and real-world evidence using statistical methodologies to predict long-term effectiveness of DVS versus SoC in patients with CPF.

METHODS

Data were pooled from a clinical trial (ADMIRE-CD) and two retrospective chart review studies (INSPECT and PREFACE). Predictive statistical models extrapolated clinical outcomes beyond observed follow-up using parametric curves, which were implemented into a semi-Markov model to obtain the number of patients in remission. The setting was multinational and multicenter. ADMIRE-CD was conducted in 49 hospitals in 7 European countries and Israel. INSPECT used data from the ADMIRE study. PREFACE involved patients from Belgium, France, Germany, Italy, and Spain. The participants were patients with complex CPF treated with DVS or SoC. Times to remission and relapse (clinical, and clinical plus patient-centric remission) were analyzed. Additionally, the proportion of patients in clinical and patient-centric remission was examined.

RESULTS

In total, 513 patients were included in the analysis (ADMIRE-CD [N = 200] and PREFACE [N = 313]). Patients in ADMIRE-CD and PREFACE were similar in age (median [interquartile range, IQR], 36 [20.0] versus 36 [22.0] years, respectively) and gender (males, 54% and 52%, respectively). The median (IQR) duration of Crohn's disease was 9.4 [11.3] years for patients in ADMIRE-CD and 6.5 [12.9] years for patients in PREFACE. The estimated time to remission was shorter for patients treated with DVS versus SoC. The estimated time to relapse was longer for patients treated with DVS versus SoC. A higher estimated proportion of patients treated with DVS versus SoC had clinical and patient-centric remission at 24 months (48% and 35%, respectively) and 48 months (49% and 32%, respectively).

CONCLUSION

This novel approach enabled pooled data from a clinical trial and real-world settings to predict long-term effectiveness of DVS versus SoC in patients with complex CPF.

Cell-based and extracellular vesicle-based MSC therapies for acute radiation syndrome affecting organ systems

Exposure to ionizing radiation can induce harmful biological effects on the human body, particularly in cases of high-dose γ-irradiation affecting the gastrointestinal tract, bone marrow, skin and lung. Such exposures lead to lethal outcomes as individuals experience a breakdown in their immune system's ability to defend against pathogens, predisposing them to sepsis-induced multiple organ failures. Mesenchymal stromal/stem cells (MSCs) possess diverse biological characteristics, including immunomodulation, anti-inflammation and tissue regeneration. Off-the-shelf culture-expanded human bone marrow- or adipose tissue-derived MSCs are clinically available to treat graft-versus-host disease following hematopoietic cell transplantation and perianal fistulas in Crohn's disease in Japan. While preclinical studies showcase encouraging outcomes in radiation-induced injuries, the effectiveness of MSC transplantation in addressing acute radiation syndrome affecting organs in irradiated individuals is limited. Recent studies have highlighted MSC-releasing extracellular vesicles as nanoparticle substances responsible for outlining the mechanism of action and have identified various components, including proteins and microRNA, that serve as functional molecules. MSC-releasing extracellular vesicle-based therapy emerges as a promising avenue, offering a potential solution to the challenges posed by radiation-induced injuries. However, further investigation is required, especially regarding whether MSC-releasing extracellular vesicles have regenerative effects on tissue-resident stem cells. These unresolved issues represent key aspects that need to be addressed to optimize the therapeutic potential of cell-based and extracellular vesicle-based MSC therapies for interventions in the context of radiation-induced injuries.

Localized Administration of Mesenchymal Stem Cell-Derived Exosomes for the Treatment of Refractory Perianal Fistula in Patients With Crohn's Disease: A Phase II Clinical Trial

BACKGROUND

Crohn's disease perianal fistulas are often resistant to standard anti-tumor necrosis factor-α therapies. Mesenchymal stem cell-derived exosomes are extracellular vesicles with highly potent anti-inflammatory effects, and the previous phase of this study demonstrated their safety in the treatment of refractory perianal fistulas.

OBJECTIVE

To evaluate the efficacy of mesenchymal stem cell-derived exosomes for the treatment of refractory perianal fistulas.

DESIGN

Nonrandomized, nonblinded single-center phase II clinical trial.

SETTINGS

Tertiary university hospital.

PATIENTS

Twenty-three patients were enrolled, 20 of whom completed the study. Refractory perianal fistula was defined as resistance to at least 1 course of treatment with anti-tumor necrosis factor-α therapy.

INTERVENTIONS

After clinical assessment and MRI, the patients received general anesthesia, and 5 mL of exosome solution was injected directly into the fistula tracts. The injections were repeated 3 times at 2-month intervals, and patients were followed monthly for 6 months after the last injection. Tissue samples from the tracts were obtained before each injection and subjected to immunohistopathological assessment. MRI data were obtained before and 6 months after the last injection.

MAIN OUTCOME MEASURES

The primary outcome of this study was fistula tract closure on clinical examination and MRI. The secondary outcome was an improvement in the discharge from the tracts.

RESULTS

Fistula tracts were fully closed in 12 patients (60%). Four patients showed clinical improvement, with some tracts remaining open, and 4 patients were completely resistant to treatment. A total of 43 fistula tracts were treated during the trial, 30 of which (69.7%) showed complete closure. Histopathological analysis revealed substantial reductions in local inflammation and signs of enhanced tissue regeneration. Immunohistochemical analysis of CD68, CD20, and CD31 reaffirmed these results.

CONCLUSIONS

Mesenchymal stem cell-derived exosomes are safe and effective for treating refractory perianal fistulas in patients with Crohn's disease. See Video Abstract .

ADMINISTRACIN LOCALIZADA DE EXOSOMAS DERIVADOS DE CLULAS MADRE MESENQUIMALES PARA EL TRATAMIENTO DE LA FSTULA PERIANAL REFRACTARIA EN PACIENTES CON ENFERMEDAD DE CROHN ENSAYO CLNICO DE FASE II

ANTECEDENTES:Las fístulas perianales de la enfermedad de Crohn a menudo son resistentes a las terapias anti-TNF-α estándares. Los exosomas derivados de células madre mesenquimales (MSC) son vesículas extracelulares que tienen efectos antiinflamatorios muy potentes, y la fase anterior de este estudio demostró su seguridad en el tratamiento de fístulas perianales refractarias.OBJETIVO:Evaluar la eficacia de los exosomas derivados de MSC para el tratamiento de fístulas perianales refractarias.DISEÑO:Ensayo clínico de fase II, no aleatorizado y no ciego, unicéntrico.LUGARES:Hospital universitario terciario.PACIENTES:Se inscribieron veintitrés pacientes, 20 de los cuales completaron el estudio. La fístula perianal refractaria se definió como la resistencia a al menos un ciclo de tratamiento con terapia anti-TNF-α.INTERVENCIONES:Después de la evaluación clínica y la resonancia magnética, los pacientes fueron sometidos a anestesia general y se inyectaron 5 ml de solución de exosoma directamente en los trayectos de la fístula. Las inyecciones se repitieron tres veces a intervalos de 2 meses y los pacientes fueron seguidos mensualmente durante 6 meses después de la última inyección. Se obtuvieron muestras de tejido de los tractos antes de cada inyección y se sometieron a evaluación inmunohistopatológica. Los datos de imágenes de resonancia magnética se obtuvieron antes y seis meses después de la última inyección.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario de este estudio fue el cierre del trayecto de la fístula en el examen clínico y la imagen de resonancia magnética. El resultado secundario fue una mejora en la descarga de los tractos.RESULTADOS:Los trayectos de la fístula se cerraron completamente en 12 (60%) de los pacientes. Cuatro pacientes mostraron mejoría clínica, algunos tractos permanecieron abiertos y cuatro pacientes fueron completamente resistentes al tratamiento. Durante el ensayo se trataron un total de 43 trayectos fistulosos, 30 (69,7%) de los cuales mostraron un cierre completo. El análisis histopatológico reveló reducciones sustanciales en la inflamación local y signos de una mayor regeneración tisular. El análisis inmunohistoquímico del grupo de diferenciación 68, 20 y 31 reafirmó estos resultados.CONCLUSIONES:Los exosomas derivados de MSC son seguros y eficaces para el tratamiento de fístulas perianales refractarias en pacientes con enfermedad de Crohn. (Traducción-Dr. Aurian Garcia Gonzalez ).

Application of mesenchymal stem/stromal cells in periodontal regeneration: Opportunities and challenges

Guided tissue regeneration (GTR) has been widely used in the periodontal treatment of intrabony and furcation defects for nearly four decades. The treatment outcomes have shown effectiveness in reducing pocket depth, improving attachment gain and bone filling in periodontal tissue. Although applying GTR could reconstruct the periodontal tissue, the surgical indications are relatively narrow, and some complications and race ethic problems bring new challenges. Therefore, it is challenging to achieve a consensus concerning the clinical benefits of GTR. With the appearance of stem cell-based regenerative medicine, mesenchymal stem/stromal cells (MSCs) have been considered a promising cell resource for periodontal regeneration. In this review, we highlight preclinical and clinical periodontal regeneration using MSCs derived from distinct origins, including non-odontogenic and odontogenic tissues and induced pluripotent stem cells, and discuss the transplantation procedures, therapeutic mechanisms, and concerns to evaluate the effectiveness of MSCs.

Artificial intelligence powers regenerative medicine into predictive realm

The expanding regenerative medicine toolkit is reaching a record number of lives. There is a pressing need to enhance the precision, efficiency, and effectiveness of regenerative approaches and achieve reliable outcomes. While regenerative medicine has relied on an empiric paradigm, availability of big data along with advances in informatics and artificial intelligence offer the opportunity to inform the next generation of regenerative sciences along the discovery, translation, and application pathway. Artificial intelligence can streamline discovery and development of optimized biotherapeutics by aiding in the interpretation of readouts associated with optimal repair outcomes. In advanced biomanufacturing, artificial intelligence holds potential in ensuring quality control and assuring scalability through automated monitoring of process-critical variables mandatory for product consistency. In practice application, artificial intelligence can guide clinical trial design, patient selection, delivery strategies, and outcome assessment. As artificial intelligence transforms the regenerative horizon, caution is necessary to reduce bias, ensure generalizability, and mitigate ethical concerns with the goal of equitable access for patients and populations.

Unveiling the immunogenicity of allogeneic mesenchymal stromal cells: Challenges and strategies for enhanced therapeutic efficacy

Mesenchymal stromal cells (MSCs) exhibit significant potential in the context of cell therapy because of their capacity to perform a range of interconnected functions in damaged tissues, including immune modulation, hematopoietic support, and tissue regeneration. MSCs are hypoimmunogenic because of their diminished expression of major histocompatibility molecules, absence of costimulatory molecules, and presence of coinhibitory molecules. While autologous MSCs reduce the risk of rejection and infection, variability in cell numbers and proliferation limits their potential applications. Conversely, allogeneic MSCs (allo-MSCs) possess broad clinical applications unconstrained by donor physiology. Nonetheless, preclinical and clinical investigations highlight that transplanted allo-MSCs are subject to immune attack from recipients. These cells exhibit anti-inflammatory and proinflammatory phenotypes contingent on the microenvironment. Notably, the proinflammatory phenotype features enhanced immunogenicity and diminished immunosuppression, potentially triggering allogeneic immune reactions that impede long-term clinical efficacy. Consequently, preserving the low immunogenicity of allo-MSCs in vivo and mitigating immune rejection in diverse microenvironments represent crucial challenges for the widespread clinical application of MSCs. In this review, we elucidate the immune regulation of allo-MSCs, specifically focusing on two distinct subgroups, MSC1 and MSC2, that exhibit varying polarization states and immunogenicity. We discuss the factors and underlying mechanisms that induce MSC immunogenicity and polarization, highlighting the crucial role of major histocompatibility complex class I/II molecules in rejection post-transplantation. Additionally, we summarize the immunogenic regulatory targets and applications of allo-MSCs and outline strategies to address challenges in this promising field, aiming to enhance allo-MSC therapeutic efficacy for patients.

Real-life effectiveness of allogeneic expanded adipose-derived mesenchymal stem cell therapy for perianal fistulizing refractory Crohn's disease

BACKGROUND

Real life data about the long-term efficacy of darvadstrocel for treating perianal fistulas in Crohn's disease (CD) remain scarce.

AIM

To report the effectiveness and safety of darvadstrocel therapy to close perianal fistula in a real-life cohort of CD patients.

METHODS

All patients with CD suffering complex draining perianal fistulas who consecutively underwent administration of a single local injection of darvadstrocel at two centres were followed up and evaluated. The primary endpoint was clinical remission (closure of all external openings with no discharge at pressure) at week 24. Combined remission (defined as clinically plus MRI-assessed fistula closure) were also assessed at week 24 and 52.

RESULTS

A total of 36 CD patients (19 Male, mean age 38.5 years) were included with a median follow up of 16 months. Clinical remission was achieved in 17 out of 36 patients (47.2 %) and combined remission in 15 out of 36 patients (41.6 %) at week 24. At week 52, clinical and combined remission was achieved in 17 out of 36 patients (47.2 %) and in 15 out of 33 evaluable patients (45.4 %), respectively.

CONCLUSION

In this real-world setting, a successful response to darvadstrocel therapy based on clinical remission was reported in around half of the patients and combined remission including radiological assessment in more than 4 out of 10 patients.

Therapeutic potential of mesenchymal stem cell-derived extracellular vesicles: A focus on inflammatory bowel disease

BACKGROUND

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as key regulators of intercellular communication, orchestrating essential biological processes by delivering bioactive cargoes to target cells. Available evidence suggests that MSC-EVs can mimic the functions of their parental cells, exhibiting immunomodulatory, pro-regenerative, anti-apoptotic, and antifibrotic properties. Consequently, MSC-EVs represent a cell-free therapeutic option for patients with inflammatory bowel disease (IBD), overcoming the limitations associated with cell replacement therapy, including their non-immunogenic nature, lower risk of tumourigenicity, cargo specificity and ease of manipulation and storage.

MAIN TOPICS COVERED

This review aims to provide a comprehensive examination of the therapeutic efficacy of MSC-EVs in IBD, with a focus on their mechanisms of action and potential impact on treatment outcomes. We examine the advantages of MSC-EVs over traditional therapies, discuss methods for their isolation and characterisation, and present mechanistic insights into their therapeutic effects through transcriptomic, proteomic and lipidomic analyses of MSC-EV cargoes. We also discuss available preclinical studies demonstrating that MSC-EVs reduce inflammation, promote tissue repair and restore intestinal homeostasis in IBD models, and compare these findings with those of clinical trials.

CONCLUSIONS

Finally, we highlight the potential of MSC-EVs as a novel therapy for IBD and identify challenges and opportunities associated with their translation into clinical practice.

HIGHLIGHTS

The source of mesenchymal stem cells (MSCs) strongly influences the composition and function of MSC-derived extracellular vesicles (EVs), affecting their therapeutic potential. Adipose-derived MSC-EVs, known for their immunoregulatory properties and ease of isolation, show promise as a treatment for inflammatory bowel disease (IBD). MicroRNAs are consistently present in MSC-EVs across cell types and are involved in pathways that are dysregulated in IBD, making them potential therapeutic agents. For example, miR-let-7a is associated with inhibition of apoptosis, miR-100 supports cell survival, miR-125b helps suppress pro-inflammatory cytokines and miR-20 promotes anti-inflammatory M2 macrophage polarisation. Preclinical studies in IBD models have shown that MSC-EVs reduce intestinal inflammation by suppressing pro-inflammatory mediators (e.g., TNF-α, IL-1β, IL-6) and increasing anti-inflammatory factors (e.g., IL-4, IL-10). They also promote mucosal healing and strengthen the integrity of the gut barrier, suggesting their potential to address IBD pathology.

Management of Perianal Fistulas Associated with Crohn Disease: A Nurse's Perspective

Crohn disease perianal fistulas are associated with considerable morbidity and impaired quality of life. Nurses who specialize in inflammatory bowel disease (IBD) play a vital role in the management of Crohn disease perianal fistulas from diagnosis to long-term care; however, there is little evidence available to inform Crohn associated perianal fistula management strategies for nurses. This narrative review aims to provide IBD nurses with an up-to-date overview of Crohn perianal fistulas. It discusses the vital role IBD nurses play within the multidisciplinary team; the physical, social, and psychological impacts of Crohn perianal fistulas on patients; available treatment options; and how IBD nurses can support patients in their perianal fistula journey to enable optimum outcomes for patients. It also reviews diagnostic techniques and IBD nurses' involvement in Crohn perianal fistula diagnosis. While this article is aimed at IBD nurses, it is relevant to all nurses irrespective of their role (unit, clinic, community, and stoma) who interact with patients with Crohn perianal fistulas because awareness of the signs and symptoms of this condition will enable timely referrals and diagnosis.

The landscape of new therapeutic opportunities for IBD

This chapter presents an overview of the emerging strategies to address the unmet needs in the management of inflammatory bowel diseases (IBD). IBD poses significant challenges, as over half of patients experience disease progression despite interventions, leading to irreversible complications, and a substantial proportion do not respond to existing therapies, such as biologics. To overcome these limitations, we describe a diverse array of novel therapeutic approaches. In the area of immune homeostasis restoration, the focus is on targeting cytokine networks, leukocyte trafficking, novel immune pathways, and cell therapies involving regulatory T cells and mesenchymal stem cells (MSC). Recognizing the critical role of impaired intestinal barrier integrity in IBD, we highlight therapies aimed at restoring barrier function and promoting mucosal healing, such as those targeting cell proliferation, tight junctions, and lipid mediators. Addressing the challenges posed by fibrosis and fistulas, we describe emerging targets for reversing fibrosis like kinase and cytokine inhibitors and nuclear receptor agonists, as well as the potential of MSC for fistulas. The restoration of a healthy gut microbiome, through strategies like fecal microbiota transplantation, rationally defined bacterial consortia, and targeted antimicrobials, is also highlighted. We also describe innovative approaches to gut-targeted drug delivery to enhance efficacy and minimize side effects. Reinforcing these advancements is the critical role of precision medicine, which emphasizes the use of multiomics analysis for the discovery of biomarkers to enable personalized IBD care. Overall, the emerging landscape of therapeutic opportunities for IBD holds great potential to surpass the therapeutic ceiling of current treatments.

Current and emerging therapeutic strategies for perianal fistula in Crohn's disease patients

The long-term remission rates achieved with current treatment options for Crohn's disease with perianal fistula (CD-PAF)-including antibiotics, biologics, immunomodulators, and Janus kinase inhibitors, often combined with advanced surgical interventions-remain unsatisfactory. This chapter explores several innovative biomaterials-based solutions, such as plugs, adhesives, fillers, and stem cell-based therapies. The key approaches and treatment outcomes of these advanced therapies are examined, focusing on their ability to modulate the immune response, promote tissue healing, and improve patient outcomes. Additionally, the chapter discusses future directions, including the optimization of biomaterial designs, enhancement of delivery and retention of regenerative therapies, and a deeper understanding of the underlying mechanisms of healing.

ECCO Guidelines on Therapeutics in Crohn's Disease: Surgical Treatment

This article is the second in a series of two publications on the European Crohn's and Colitis Organisation [ECCO] evidence-based consensus on the management of Crohn's disease. The first article covers medical management; the present article addresses surgical management, including preoperative aspects and drug management before surgery. It also provides technical advice for a variety of common clinical situations. Both articles together represent the evidence-based recommendations of the ECCO for Crohn's disease and an update of prior ECCO Guidelines.

Effectiveness of autologous emulsified stromal vascular fraction tissue injection for the treatment of complex perianal fistulas in inflammatory bowel diseases patients: a pilot study

Complex fistulizing perianal disease is a disabling manifestation of inflammatory bowel disease (IBD), seriously compromising patients 'quality of life'. The success rate of available treatments is quite low, and nearly half of the patients will develop chronically active fistulas or experience fistula recurrence. Mesenchymal stem cell therapy has shown interesting results, but the complexity and the cost of production limit its widespread use. This study aims to report the results of the innovative use of autologous emulsified adipose-derived stromal vascular fraction tissue for treating complex fistulizing perianal disease. From March 2021 to March 2022, 10 patients underwent a two-step procedure: (1) examination under anaesthesia, with loose seton drainage and 4 weeks later and (2) curettage of the fistulous tract, internal fistula closure and an injection of autologous emulsified adipose-derived stromal vascular fraction tissue harvested from the subcutaneous layer of the patient's hip. Clinical and radiological (through magnetic resonance imaging) healing were assessed at 6 months. We included five patients affected by Crohn's disease, three by ulcerative colitis and two by indeterminate colitis. All patients were on concomitant biological therapy (50% on Infliximab). One patient required a re-treatment for a relapse and two different fistulas were separately treated in another one. Out of 12 total procedures performed, clinical healing was achieved in 10 cases (83%), while radiological healing in 6 patients (50%). No adverse events were recorded. Autologous emulsified adipose-derived stromal vascular fraction tissue can represent an effective, safe and cheap add-on therapy for patients with complex perianal fistulas in IBDs.

Management of Perianal Fistulizing Crohn's Disease

Perianal fistulizing Crohn's disease (CD) represents a severe phenotype of CD that is associated with significant morbidity and reduction in quality of life. Perianal fistulizing CD is caused by a complex interplay of genetic predisposition, immune dysregulation, gut dysbiosis, and various unknown physiological and mechanical factors. A multidisciplinary approach is hence required for optimal management . A detailed anatomical description and classification of perianal fistula, including comprehensive clinical, endoscopic, and radiological diagnostic workup, is an important prerequisite to treatment. For simple perianal fistulas, use of antibiotics and immunomodulators, with or without fistulotomy, are appropriate measures. The medical management of complex perianal fistula, on the other hand, requires adequate control of infection before initiation of therapy with immunomodulators. In active complex perianal fistula, anti-tumor necrosis factors remain the most accepted therapy, with concomitant use of antibiotics or immunomodulators enhancing the efficacy. For patients refractory to anti-tumor necrosis factors, treatment with anti-integrins, anti-interleukins, and small molecules is being evaluated. Mesenchymal stem cells, hyperbaric oxygen therapy, and exclusive enteral nutrition have also been investigated as adjunct therapies. Despite the expansion of the medical armamentarium, a large proportion of the patients require surgical interventions. In this review, we provide an up-to-date overview of the pathophysiology, clinical presentation, diagnosis, and medical management of perianal fistulizing CD. A brief overview of the surgical management of perianal fistulizing CD is also provided.

Closing the internal opening with a rectal advancement flap increases the efficacy of mesenchymal stem cell injection for complex Crohn's disease anal fistulas

BACKGROUND

The efficacy of injections of mesenchymal stem cells (MSC) for anal fistula treatment may be impaired by the persistence of stools passing into the fistula, causing bacterial contamination and a local inflammatory reaction. We aimed to compare remission rates between patients treated by MSC injection with simple sutures and those treated with a rectal advancement flap.

METHODS

This single-center prospective study compared the first patients who underwent internal opening closure with sutures with the subsequent patients treated with a flap. Complete clinical remission was defined as complete closure of the external opening(s) without pain or discharge, and complete radiological remission was defined as a Magnifi-CD score of 0.

RESULTS

We compared the first 42 patients who had sutures with the 20 subsequent patients who had an advancement flap. The median follow-up was 15.5 [8.8-24.9] months. The cumulative incidence of complete clinical response at M12 was 53.8% [38.1-69.6%] in the suture group versus 93.3% [77.4-100.0] in the flap group (p < 0.001). The Magnifi-CD score was 0 for 41.7% [25.5-59.2%]) of patients treated with sutures versus 72.7% [39.0-63.9%]) of patients treated with a flap (p = 0.093). Anal incontinence score did not differ between the two groups. Practicing an advancement flap was the only significant factor associated with complete clinical remission over time (adjusted HR [95% CI] of 2.6 [1.4-4.9], p = 0.003).

CONCLUSIONS

Complete clinical remission rates following MSC injection are significantly higher after closure of the internal opening with a rectal flap than after closure with sutures, without consequences on anal continence.

Adipose-derived mesenchymal stromal cells in clinical trials: Insights from single-cell studies

Mesenchymal Stromal Cells (MSCs) offer tremendous potential for the treatment of various diseases and their healing properties have been explored in hundreds of clinical trials. These trails primarily focus on immunological and neurological disorders, as well as regenerative medicine. Adipose tissue is a rich source of mesenchymal stromal cells and methods to obtain and culture adipose-derived MSCs (AD-MSCs) have been well established. Promising results from pre-clinical testing of AD-MSCs activity prompted clinical trials that further led to the approval of AD-MSCs for the treatment of complex perianal fistulas in Crohn's disease and subcutaneous tissue defects. However, AD-MSC heterogeneity along with various manufacturing protocols or different strategies to boost their activity create the need for standardized quality control procedures and safety assessment of the intended cell product. High-resolution transcriptomic methods have been recently gaining attention, as they deliver insight into gene expression profiles of individual cells, helping to deconstruct cellular hierarchy and differentiation trajectories, and to understand cell-cell interactions within tissues. This article presents a comprehensive overview of completed clinical trials evaluating the safety and efficacy of AD-MSC treatment, together with current single-cell studies of human AD-MSC. Furthermore, our work emphasizes the increasing significance of single-cell research in elucidating the mechanisms of cellular action and predicting their therapeutic effects.

The Role of Small-Bowel Capsule Endoscopy in the Diagnostic Algorithm of Complicated Perianal Disease

INTRODUCTION

Complicated perianal disease (cPD) may be the sole presentation of Crohn's disease (CD). The role of small-bowel capsule endoscopy (SBCE) in the diagnostic algorithm of cPD is unclear. We aimed to evaluate the role of SBCE as a diagnostic tool, in patients with cPD, after a negative standard workup for CD.

METHODS

A multicenter, retrospective, cross-sectional study, in patients with cPD, and negative standard workup for CD (ileocolonoscopy and cross-sectional imaging), who underwent SBCE for suspected CD. Demographics, biomarkers, and the Lewis Score (LS) were recorded and analyzed. An LS ≥ 135 was considered a positive SBCE for diagnosing CD.

RESULTS

Ninety-one patients were included: 65 (71.4%) males; median age: 37 (29-51) years; cPD duration: 25.1 (12.5-66.1) months. Positive SBCE: 24/91 (26.4%) patients. Fecal calprotectin (FC) positively correlated with LS (r = 0.81; p < 0.001). FC levels of 100 µg/g and 50 µg/g had a sensitivity of only 40% and 55% to rule out small-bowel CD, with a negative predictive value (NPV) of only 76% and 80%, respectively.

CONCLUSIONS

SBCE contributed to CD diagnosis in a quarter of patients with cPD after a negative standard workup. FC levels correlated with the degree of inflammation defined by the LS. However, the NPV of FC was low, suggesting that SBCE should be considered for patients with cPD even after a negative standard workup.

Multimodal single-cell analyses reveal mechanisms of perianal fistula in diverse patients with Crohn's disease

BACKGROUND

Crohn's disease complicated by perianal fistulae is more prevalent and severe in patients of African ancestry.

METHODS

We profiled single cells from diverse patients with Crohn's disease with perianal fistula from colorectal mucosa and fistulous tracts. Immunofluorescence was performed to validate predicted cell-cell interactions. Unstimulated monocytes were chronically cultured in diverse cohorts. A subset was analyzed by single-nucleus RNA + ATAC sequencing.

FINDINGS

Fistulous tract cells from complete proctectomies demonstrated enrichment of myeloid cells compared to paired rectal tissues. Ligand-receptor analysis highlights myeloid-stromal cross-talk and cellular senescence, with cellular co-localization validated by immunofluorescence. Chitinase-3 like-protein-1 (CHI3L1) is a top upregulated gene in stromal cells from fistulae expressing both destructive and fibrotic gene signatures. Monocyte cultures from patients of African ancestry and controls demonstrated differences in CHI3L1 and oncostatin M (OSM) expression upon differentiation compared to individuals of European ancestry. Activating protein-1 footprints are present in ATAC-seq peaks in stress response genes, including CHI3L1 and OSM; genome-wide chromatin accessibility including JUN footprints was observed, consistent with reported mechanisms of inflammatory memory. Regulon analyses confirm known cell-specific transcription factor regulation and implicate novel ones in fibroblast subsets. All pseudo-bulked clusters demonstrate enrichment of genetic loci, establishing multicellular contributions. In the most significant African American Crohn's genetic locus, upstream of prostaglandin E receptor 4, lymphoid-predominant ATAC-seq peaks were observed, with predicted RORC footprints.

CONCLUSIONS

Population differences in myeloid-stromal cross-talk implicate fibrotic and destructive fibroblasts, senescence, epigenetic memory, and cell-specific enhancers in perianal fistula pathogenesis. The transcriptomic and epigenetic data provided here may guide optimization of promising mesenchymal stem cell therapies for perianal fistula.

FUNDING

This work was supported by grants U01DK062422, U24DK062429, and R01DK123758.

Vascular endothelial growth factor secretion and immunosuppression are distinct potency mechanisms of human bone marrow mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) are investigated as cellular therapeutics for inflammatory bowel diseases and associated perianal fistula, although consistent efficacy remains a concern. Determining host factors that modulate MSCs' potency including their secretion of angiogenic and wound-healing factors, immunosuppression, and anti-inflammatory properties are important determinants of their functionality. We investigated the mechanisms that regulate the secretion of angiogenic and wound-healing factors and immune suppression of human bone marrow MSCs. Secretory analysis of MSCs focusing on 18 angiogenic and wound-healing secretory molecules identified the most abundancy of vascular endothelial growth factor A (VEGF-A). MSC viability and secretion of other angiogenic factors are not dependent on VEGF-A secretion which exclude the autocrine role of VEGF-A on MSC's fitness. However, the combination of inflammatory cytokines IFNγ and TNFα reduces MSC's VEGF-A secretion. To identify the effect of intestinal microvasculature on MSCs' potency, coculture analysis was performed between human large intestine microvascular endothelial cells (HLMVECs) and human bone marrow-derived MSCs. HLMVECs do not attenuate MSCs' viability despite blocking their VEGF-A secretion. In addition, HLMVECs neither attenuate MSC's IFNγ mediated upregulation of immunosuppressive enzyme indoleamine 2,3-dioxygenase nor abrogate suppression of T-cell proliferation despite the attenuation of VEGF-A secretion. We found that HLMVECs express copious amounts of endothelial nitric oxide synthase and mechanistic analysis showed that pharmacological blocking reverses HLMVEC-mediated attenuation of MSC's VEGF-A secretion. Together these results suggest that secretion of VEGF-A and immunosuppression are separable functions of MSCs which are regulated by distinct mechanisms in the host.

Interventional endoscopy in inflammatory bowel disease: a comprehensive review

Interventional endoscopy can play a key role in the multidisciplinary management of complex inflammatory bowel disease (IBD) as an adjunct to medical and surgical therapy. The primary role of interventional IBD (IIBD) includes the treatment of Crohn's disease-related stricture, fistula, and abscess. Endoscopic balloon dilation (EBD), endoscopic stricturotomy, and placement of endoscopic stents are different forms of endoscopic stricture therapy. EBD is the most widely used therapy whereas endoscopic stricturotomy has higher long-term efficacy than EBD. Fully covered and partially covered self-expanding metal stents are useful in long and refractory strictures whereas lumen-apposing metal stents can be used in short, and anastomotic strictures. Endoscopic fistula/abscess therapy includes endoscopic fistulotomy, seton placement, endoscopic ultrasound-guided drainage of rectal/pelvic abscess, and endoscopic injection of filling agents (fistula plug/glue/stem cell). Endoscopic seton placement and fistulotomy are mainly feasible in short, superficial, single tract fistula and in those with prior surgical seton placement. Similarly, endoscopic fistulotomy is usually feasible in short, superficial, single-tract fistula. Endoscopic closure therapies like over-the-scope clips, suturing, and self-expanding metal stent should be avoided for de novo/bowel to hollow organ fistulas. Other indications include management of postoperative complications in IBD such as management of surgical leaks and complications of pouchitis in ulcerative colitis. Additional indications include endoscopic resection of ulcerative colitis-associated neoplasia (by endoscopic mucosal resection, endoscopic submucosal dissection, and endoscopic full-thickness resection), retrieval of retained capsule endoscope, and control of bleeding. IIBD therapies can potentially act as a bridge between medical and surgical therapy for properly selected IBD patients.

Efficacy of injection of autologous adipose tissue in the treatment of patients with complex and recurrent fistula-in-ano of cryptoglandular origin

BACKGROUND

Adipose tissue injections, a rich source of mesenchymal stem cells, have been successfully used to promote anal fistula healing. This study aimed to investigate the efficacy of adipose tissue injection in treating patients with complex and recurrent fistulas of cryptoglandular origin.

METHODS

We conducted a prospective, single-center, open-label, non-randomized, interventional clinical trial from January 2020 to December 2022. We enrolled nine patients, who were evaluated after at least 12 months of follow-up. All patients had seton removal, fistula tract excision or curettage, and a mucosal flap if possible or, alternatively, an internal opening suture. We used a commercially available system to collect and process adipose tissue prior to injection. This system allowed the collection, microfragmentation, and filtration of tissue.

RESULTS

Selected cases included six men and three women with a median age of 42 (range 31-55) years. All patients had an extended disease course period, ranging from 3 to 13 (mean 6.6) years, and a history of multiple previous surgeries, including two to eight interventions (a mean of 4.4 per case). All fistulas were high transsphincteric, four cases horseshoe and two cases with secondary suprasphincteric or peri-elevator tract fistulas. Six cases (66%) achieved complete fistula healing at a mean follow-up of 18 (range 12-36) months. Three cases (33.3%) experienced reduced secretion and decreased anal discomfort.

CONCLUSIONS

In patients with complex and recurrent fistulas, such as the ones described, many from palliative treatments with setons, the adjuvant injection of adipose tissue might help achieve complete healing or improvement in a significant percentage of cases.

CLINICALTRIALS

The study protocol was prospectively registered on ClinicalTrials.gov (NCT04750499).

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.

Navigating the complexities of drug development for inflammatory bowel disease

Inflammatory bowel disease (IBD) - consisting of ulcerative colitis and Crohn's disease - is a complex, heterogeneous, immune-mediated inflammatory condition with a multifactorial aetiopathogenesis. Despite therapeutic advances in this arena, a ceiling effect has been reached with both single-agent monoclonal antibodies and advanced small molecules. Therefore, there is a need to identify novel targets, and the development of companion biomarkers to select responders is vital. In this Perspective, we examine how advances in machine learning and tissue engineering could be used at the preclinical stage where attrition rates are high. For novel agents reaching clinical trials, we explore factors decelerating progression, particularly the decline in IBD trial recruitment, and assess how innovative approaches such as reconfiguring trial designs, harmonizing end points and incorporating digital technologies into clinical trials can address this. Harnessing opportunities at each stage of the drug development process may allow for incremental gains towards more effective therapies.

Organoids as regenerative medicine for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic disorder with an increasing global prevalence. Managing disease activity relies on various pharmacological options. However, the effectiveness of current therapeutics is limited and not universally applicable to all patients and circumstances. Consequently, developing new management strategies is necessary. Recent advances in endoscopically obtained intestinal biopsy specimens have highlighted the potential of intestinal epithelial organoid transplantation as a novel therapeutic approach. Experimental studies using murine and human organoid transplantations have shown promising outcomes, including tissue regeneration and functional recovery. Human trials with organoid therapy have commenced; thus, this article provides readers with insights into the necessity and potential of intestinal organoid transplantation as a new regenerative therapeutic option in clinical settings and explores its associated challenges.

Diagnosis and Medical Treatment of Acute and Chronic Idiopathic Pouchitis in Inflammatory Bowel Disease

Despite the decreased rates in inflammatory bowel disease (IBD) colectomies due to high advances in therapeutic options, a significant number of patients still require proctocolectomy with ileal pouch-anal anastomosis (IPPA) for ulcerative colitis (UC). Pouchitis is the most common complication in these patients, where up to 60% develop one episode of pouchitis in the first two years after UC surgery with IPAA with severe negative impact on their quality of life. Acute cases usually respond well to antibiotics, but 15% of patients will still develop a refractory disease that requires the initiation of advanced immunosuppressive therapies. For chronic idiopathic pouchitis, current recommendations suggest using the same therapeutic options as for IBD in terms of biologics and small molecules. However, the available data are limited regarding the effectiveness of different biologics or small molecules for the management of this condition, and all evidences arise from case series and small studies. Vedolizumab is the only biologic agent that has received approval for the treatment of adult patients with moderately to severely active chronic refractory pouchitis. Despite the fact that IBD treatment is rapidly evolving with the development of novel molecules, the presence of pouchitis represents an exclusion criterion in these trials. Recommendations for the approach of these conditions range from low to very low certainty of evidence, resulting from small randomized controlled trials and case series studies. The current review focuses on the therapeutic management of idiopathic pouchitis.

Mesenchymal stem cell therapy for therapy refractory complex Crohn's perianal fistulas: a case series

BACKGROUND

Mesenchymal stem cell treatment (MST) has emerged as a new therapeutic strategy for Crohn's perianal fistulas. It has been demonstrated that a fibrotic tract on MRI with a MAGNIFI-CD score ≤ 6 is the best predictor for long-term clinical closure. Therefore, the aim of the current study was to analyse the effectiveness of MST for complex Crohn's perianal fistulas based on MRI.

METHODS

Consecutive patients with complex Crohn's perianal fistulas, previously failing both anti-TNF treatment and surgical closure, who had surgical closure of the internal opening with MST were included. The primary endpoint was radiological remission of the fistula(s) defined as a MAGNIFI-CD ≤ 6 on MRI, read by an experienced radiologist.

RESULTS

Between December 2019 and March 2023, 30 patients (15 males) with 48 fistula tracts were included with a median follow-up of 16.5 months. Radiological remission was achieved in thirteen patients (43.3%) after a median follow-up of 5.0 months (IQR 3.0-6.0). The median MAGNIFI-CD at baseline was 15.0 (IQR 7.0-20.0) which significantly decreased to 8.0 (IQR 3.0-15.0) after treatment (p = 0.001). Clinical closure was achieved in 21 patients (70.0%). Three patients (14.3%) developed a recurrence during long-term FU, all with clinically closed fistula(s), but no radiological remission. The median PDAI decreased significantly from 10.5 (IQR 7.0-14.0) to 4.0 (IQR 0.0-7.3) (p = 0.001).

CONCLUSION

MST is a promising treatment strategy for therapy refractory Crohn's perianal fistulas, resulting in > 40% radiological remission, clinical closure in 70% and a significant improvement in quality of life. No recurrences were seen in patients with radiological remission.

Efficacy and Safety of Filgotinib for the Treatment of Perianal Fistulising Crohn's Disease [DIVERGENCE 2]: A Phase 2, Randomised, Placebo-controlled Trial

BACKGROUND AND AIMS

There is an unmet need in the treatment of perianal fistulising Crohn's disease [PFCD]. This study evaluated the efficacy and safety of the Janus kinase 1 preferential inhibitor, filgotinib, for the treatment of PFCD.

METHODS

This phase 2, double-blind, multicentre trial enrolled adults with PFCD and prior treatment failure. Participants were randomised [2:2:1] to receive filgotinib 200 mg, filgotinib 100 mg, or placebo, once daily orally for up to 24 weeks. The primary endpoint was combined fistula response (reduction from baseline of at least one draining external opening determined by physical assessment, and no fluid collections >1 cm on pelvic magnetic resonance imaging [MRI]) at Week 24.

RESULTS

Between April 2017 and July 2020, 106 individuals were screened and 57 were randomised. Discontinuations were lowest in the filgotinib 200 mg group (3/17 [17.6%] versus 13/25 [52.0%] for filgotinib 100 mg and 9/15 [60.0%] for placebo). The proportion of participants who achieved a combined fistula response at Week 24 was 47.1% (8/17; 90% confidence interval [CI] 26.0, 68.9%) in the filgotinib 200 mg group, 29.2% [7/24; 90% CI 14.6, 47.9%] in the filgotinib 100 mg group, and 25.0% [3/12; 90% CI 7.2, 52.7%] in the placebo group. Serious adverse events occurred more frequently with filgotinib 200 mg (5/17 [29.4%]) than with placebo (1/15 [6.7%]). There were no treatment-related serious adverse events or deaths.

CONCLUSIONS

Filgotinib 200 mg was associated with numerical reductions in the number of draining perianal fistulas based on combined clinical and MRI findings compared with placebo, and was generally well tolerated [NCT03077412].

A phase I/II clinical trial of ex-vivo expanded human bone marrow derived allogeneic mesenchymal stromal cells in adult patients with perianal fistulizing Crohn's Disease

BACKGROUND

Perianal fistulas (PF) affect one-third patients with Crohn's disease (CD) with limited therapeutic options. There is dearth of literature on safety and efficacy of bone marrow-derived mesenchymal stromal cells (BMSCs) in this population.

METHODS

An open-label, phase I/II, single-arm study was conducted involving local administration of human allogeneic bone marrow-derived mesenchymal stromal cells in perianal fistula of patients with Crohn's disease refractory to standard therapies. Clinical severity and biomarkers were assessed at baseline and periodically until week 104 , and MRI at week 24 and 104. Primary and secondary objectives were to assess safety and efficacy respectively. Fistula remission was complete closure of fistula openings with < 2 cm perianal collection on MRI, and fistula response was decrease in drainage by ≥ 50%. Change in perianal disease activity index, quality-of-life and Van Assche index on MRI over time was assessed using mixed-effect linear regression model.

RESULTS

Ten patients (male:8, mean age:27.4 ± 12.0years) were recruited. Self-resolving procedure-related adverse events occurred in three patients, with no follow-up adverse events. In intention to treat analysis at week 24, two patients (20%) achieved fistula remission and seven (70%) had fistula response. At week 52, two (20%) patients were in remission and seven (70%) maintained response. At 104 weeks, two (20%) patients maintained response and one (10%) was in remission. Statistically significant decrease in perianal disease activity index (P = 0.008), Van Assche Index (P = 0.008) and improvement in quality-of-life (P = 0.001) were observed over time.

CONCLUSIONS

Allogeneic BMSCs are safe and effective for the treatment of perianal fistulizing CD with significant improvement in clinical severity and radiological healing.

TRIAL REGISTRATION

The study was prospectively registered on Clinical trials registry - India (CTRI), CTRI/2020/01/022743 on 14 January 2020, http://ctri.nic.in .

Efficacy of cx601 (darvadstrocel) for the treatment of perianal fistulizing Crohn's disease-A prospective nationwide multicenter cohort study

BACKGROUND

The use of mesenchymal stem cells is considered a novel and promising therapeutic option for patients with perianal fistulizing Crohn's disease; however, data on its clinical application remain scarce. This multicenter nationwide study aimed to assess the clinical efficacy of mesenchymal stem cells in closing complex anal fistulas.

METHODS

In this study 14 Crohn's disease patients (3 males, 11 females) with complex anal fistulas treated in 3 tertiary hospitals in Austria were included between October 2018 and April 2021. Injection of 120 million allogeneic expanded adipose-derived mesenchymal stem cells (Cx601-darvadstrocel) was performed in each patient. Closure of the external fistula opening without secretion by external manual compression was defined as treatment success.

RESULTS

The median age of the patient population at the time of surgery was 32 years (range 26-53 years) with a median body mass index of 21.7 kg/m2 (range 16.7-26.6 kg/m2). Of the patients 12 (86%) received monoclonal antibodies (infliximab, adalimumab, ustekinumab, vedolizumab) at the time of surgery. The median number of complex fistulas was 1.4 (range 1-2), The median operative time was 20 min (range 6-50 min) with no perioperative complications. After a median follow-up of 92 weeks, we found successful fistula closure in 57.1% (n = 8) of treated patients. The perianal disease activity index did not improve significantly from initially 7 to a median of 6 after 52 weeks (p = 0.495).

CONCLUSION

Darvadstrocel is a safe, minimally invasive surgical technique without significant perioperative complications. Clinical success can be expected in about half of the treated patients.

Development of an MRI-Based Prediction Model for Anti-TNF Treatment Failure in Perianal Crohn's Disease: A Multicenter Study

BACKGROUND & AIMS

Clinical and radiologic variables associated with perianal fistula (PAF) outcomes are poorly understood. We developed prediction models for anti-tumor necrosis factor (TNF) treatment failure in patients with Crohn's disease-related PAF.

METHODS

In a multicenter retrospective study between 2005 and 2022 we included biologic-naive adults (>17 years) who initiated their first anti-TNF therapy for PAF after pelvic magnetic resonance imaging (MRI). Pretreatment MRI studies were prospectively reread centrally by blinded radiologists. We developed and internally validated a prediction model based on clinical and radiologic parameters to predict the likelihood of anti-TNF treatment failure, clinically, at 6 months. We compared our model and a simplified version of MRI parameters alone with existing imaging-based PAF activity indices (MAGNIFI-CD and modified Van Assche MRI scores) by De Long statistical test.

RESULTS

We included 221 patients: 32 ± 14 years, 60% males, 76% complex fistulas; 68% treated with infliximab and 32% treated with adalimumab. Treatment failure occurred in 102 (46%) patients. Our prediction model included age at PAF diagnosis, time to initiate anti-TNF treatment, and smoking and 8 MRI characteristics (supra/extrasphincteric anatomy, fistula length >4.3 cm, primary tracts >1, secondary tracts >1, external openings >1, tract hyperintensity on T1-weighted imaging, horseshoe anatomy, and collections >1.3 cm). Our full and simplified MRI models had fair discriminatory capacity for anti-TNF treatment failure (concordance statistic, 0.67 and 0.65, respectively) and outperformed MAGNIFI-CD (P = .002 and < .0005) and modified Van Assche MRI scores (P < .0001 and < .0001), respectively.

CONCLUSIONS

Our risk prediction models consisting of clinical and/or radiologic variables accurately predict treatment failure in patients with PAF.

Pharmacological Therapies for the Management of Fistulizing Crohn's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Fistulas are a debilitating complication of Crohn's disease [CD]. We conducted a systematic review to assess the efficacy of medical therapies for fistulizing CD.

METHODS

MEDLINE, Embase, and CENTRAL were searched on May 26, 2022, for randomized controlled trials [RCTs] of pharmacological therapy in adults with fistulizing CD. The primary outcome was induction and maintenance of fistula response. Pooled risk ratios [RRs] and 95% confidence intervals [CIs] were calculated. GRADE was used to assess the certainty of evidence.

RESULTS

Thirty-eight RCTs were included. Nineteen trials [50%] exclusively involved perianal fistula. The remaining studies included some participants with non-perianal fistula. Pooled RRs for anti-tumour necrosis factor [TNF] agents were not statistically significant for induction [RR 1.36, 95% CI 0.97-1.91] or maintenance of fistula response [RR 1.48, 95% CI 0.97-2.27]. However, in a sensitivity analysis of studies with fistula response as the primary outcome, anti-TNFs were superior to placebo for induction [RR 1.94, 95% CI 1.10-3.41] and maintenance [RR 1.88, 95% CI 1.23-2.88] of fistula response. Oral small molecules [RR 2.56, 95% CI 1.18-5.53] and mesenchymal stem cell [MSC] therapy [RR 1.26, 95% CI 1.01-1.57] were effective for induction of fistula response. Ustekinumab was associated with maintenance of fistula response [RR 1.80, 95% CI 1.04-3.11]. Vedolizumab was not superior to placebo. The certainty of evidence ranged from very low to moderate.

CONCLUSION

Very low- to moderate-certainty evidence suggests that anti-TNF therapy, oral small molecules, ustekinumab, and MSCs are effective for perianal fistulizing CD. Dedicated fistula studies evaluating biologics and small molecules are needed.

A first-in-human clinical study of laparoscopic autologous myoblast sheet transplantation to prevent delayed perforation after duodenal endoscopic mucosal dissection

BACKGROUND

The detection rate of superficial non-ampullary duodenal epithelial tumors (SNADETs) has recently been increasing. Large tumors may contain malignant lesions and early therapeutic intervention is recommended. Endoscopic mucosal dissection (ESD) is considered a feasible treatment modality, however, the anatomical and physiological characteristics of the duodenum create a risk of postoperative perforation after ESD.

METHODS

To explore whether myoblast sheet transplantation could prevent delayed perforation after ESD, a first-in-human (FIH) clinical trial of laparoscopic autologous myoblast sheet transplantation after duodenal ESD was launched. Autologous myoblast sheets fabricated from muscle tissue obtained seven weeks before ESD were transplanted laparoscopically onto the serous side of the ESD. The primary endpoints were the onset of peritonitis due to delayed perforation within three days after surgery and all adverse events during the follow-up period.

RESULTS

Three patients with SNADETs ≥ 20 mm in size underwent transplantation of a myoblast sheet onto the serous side of the duodenum after ESD. In case 1, The patient's postoperative course was uneventful. Endoscopy and abdominal computed tomography revealed no signs of delayed perforation. Despite incomplete mucosal closure in case 2, and multiple micro perforations during ESD in case 3, cell sheet transplantation could prevent the postoperative massive perforation after ESD, and endoscopy on day 49 after transplantation revealed no stenosis.

CONCLUSIONS

This clinical trial showed the safety, efficacy, and procedural operability of this novel regenerative medicine approach involving transplanting an autologous myoblast sheet laparoscopically onto the serosa after ESD in cases with a high risk of delayed perforation. This result indicates the potential application of cell sheet medicine in treating various abdominal organs and conditions with minimal invasiveness in the future.

TRIAL REGISTRATION

jRCT, jRCT2073210094. Registered November 8 2021, https://jrct.niph.go.jp/latest-detail/jRCT2073210094 .

First Mexican Consensus on Crohn's disease

INTRODUCTION

Crohn's disease (CD) is a subtype of chronic and incurable inflammatory bowel disease. It can affect the entire gastrointestinal tract and its etiology is unknown.

OBJECTIVE

The aim of this consensus was to establish the most relevant aspects related to definitions, diagnosis, follow-up, medical treatment, and surgical treatment of Crohn's disease in Mexico.

MATERIAL AND METHODS

Mexican specialists in the areas of gastroenterology and inflammatory bowel disease were summoned. The consensus was divided into five modules, with 69 statements. Applying the Delphi panel method, the pre-meeting questions were sent to the participants, to be edited and weighted. At the face-to-face meeting, all the selected articles were shown, underlining their level of clinical evidence; all the statements were discussed, and a final vote was carried out, determining the percentage of agreement for each statement.

RESULTS

The first Mexican consensus on Crohn's disease was produced, in which recommendations for definitions, classifications, diagnostic aspects, follow-up, medical treatment, and surgical treatment were established.

CONCLUSIONS

Updated recommendations are provided that focus on definitions, classifications, diagnostic criteria, follow-up, and guidelines for conventional medical treatment, biologic therapy, and small molecule treatment, as well as surgical management.

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.