Small bowel Crohn's disease (SBCD) is increasingly treated with biological therapies. Predicting response or remission (RoR) for individual patients is difficult and complicates treatment strategy. We aimed to determine if motility magnetic resonance imaging (mMRI) is superior to CRP and fecal calprotectin (FC) for the prediction of RoR at 1 year in patients commencing biologics for SBCD.

Prospective, multicenter (n = 13) cohort study of patients with active non-stricturing SBCD requiring anti-TNFα or anti-IL-12/23 treatment. We measured mMRI and CRP at baseline and post-induction (visit 2: 12-30 weeks), and FC in a subset. RoR was assessed at 1 year using clinical and structural magnetic resonance enterography parameters. We compared sensitivity, specificity, and area under the receiver operating characteristic curve (ROC-AUC) of changes in mMRI and CRP to predict RoR at 1 year. Secondary outcomes compared mMRI with FC, and prediction of improved quality of life (QoL).

Eighty-six participants completed all assessments. Stable or improved mMRI at visit 2 was more sensitive than normalization of CRP for RoR (mMRI:71.0%, 95%CI 52.0-85.8; CRP:45.2%, 95%CI 27.3-64.0%, P = .008) but less specific (mMRI:30.9%, 95%CI 19.1-44.8; CRP:67.3%, 95%CI 53.3-79.3%, P < .001). There was no significant difference in ROC-AUC (mMRI:0.48; CRP:0.53, P = .65). Similar results were obtained for FC. None of mMRI, CRP, or FC predicted patient QoL at 1 year.

Although improved mMRI is more sensitive than CRP and FC to predict RoR at 1 year, it is less specific. No factor predicted patient QoL. Motility MRI remains a marker of disease activity at given timepoints.

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.

There is an increasing need for objective treatment monitoring in perianal fistulising Crohn's disease (pfCD). Therefore, the magnetic resonance novel index for fistula imaging in CD (MAGNIFI-CD) index has been designed and internally validated on the ADMIRE-CD trial cohort. The aim of this study was to externally validate the MAGNIFI-CD index to monitor response to medical and surgical treatment regimens in pfCD.

A retrospective longitudinal cohort was established of consecutive patients with complex pfCD treated with surgical and/or medical therapy and a baseline and follow-up MRI between January 2007 and May 2021. The MAGNIFI-CD index was scored by two independent, abdominal radiologists blinded for time points and clinical outcomes. Responsiveness, reliability, and test accuracy regarding clinically important improvement were assessed. Cut-offs for response and remission were selected classified on fistula drainage assessment and physician global assessment.

A total of 65 patients (51% female, median age 32 years) were included. A clinically relevant responsiveness of the MAGNIFI-CD was shown, with a significant decrease in clinical remitters and responders with a median MAGNIFI-CD of 18.0 [7.5-20.0] to 9.0 [0.8-16.0] (p < 0.001) and non-significant change in non-responders with a median MAGNIFI-CD of 20.0 [12.0-23.0] to 18.0 [13.0-21.0] (p = 0.22). There was an 'almost perfect' interobserver agreement (ICC = 0.87; 95% CI 0.80-0.92) for the MAGNIFI-CD index. An optimal cut-off value was defined as a decrease of 2 points for clinical response, and a MAGNIFI-CD ≤ 6 for remission at follow-up MRI.

The MAGNIFI-CD index is a responsive and reliable MRI scoring instrument for treatment monitoring in perianal fistulising Crohn's disease.

The MAGNIFI-CD index is a well-structured, responsive scoring instrument to assess fistula severity and activity that allows quantitative detection of changes in therapy response in patients with perianal fistulising Crohn's disease, thereby facilitating endpoints in clinical trials.

Well-defined cut-offs for response and remission are needed for objective treatment monitoring of perianal fistulising Crohn's disease (pfCD). Cut-off values for remission and for response at 6 months follow-up were defined. Interobserver agreement was good. The MAGNIFI-CD index is responsive and reliable for treatment monitoring and is suitable for use in clinical trials.

Advanced therapies (ADT) that encompass biological agents and small molecules have been approved for the treatment of inflammatory bowel disease (IBD), broadening the spectrum of available treatment options. Nevertheless, a substantial proportion of patients fail to achieve satisfactory responses, necessitating surgical intervention. Treatment objectives have evolved beyond clinical remission, reduction of inflammation, and mucosal healing, shifting focus toward enhancing the quality of life, acknowledging the profound impact of IBD on physical and mental well-being.

This comprehensive review describes the current landscape of ADT for IBD, including dual biologic therapy (DBT), which involves the combination of two biologics or a single biologic with a small-molecule compound, as well as considerations surrounding the discontinuation of biologics.

ADT is the standard treatment for moderate to severe IBD, while DBT appears promising for specific subsets of patients, including those with refractory disease or extraintestinal manifestations. However, these approaches may increase the risk of adverse effects, including malignancy. To optimize individualized treatment strategies in patients with refractory IBD, further trials are needed to refine ADT's predictive value, establish DBT's safety and indications, define biologic discontinuation criteria, and evaluate emerging biomarkers, artificial intelligence, and bowel ultrasound in patient management.

Perianal fistulizing Crohn's disease (PFCD) is a challenging and debilitating phenotype of Crohn's disease that can negatively affect quality of life. Studies have begun to uncover the physiologic mechanisms involved in wound repair as it relates to PFCD and how aberrations in these mechanisms may contribute to fistula persistence.

To review the physiologic and pathophysiologic mechanisms of wound repair in PFCD and how specific therapeutic strategies may impact their outcomes.

We reviewed the latest published literature on wound repair as it relates to PFCD.

Wound repair can be categorised into three overlapping biological phases: localised inflammation, cell recruitment/proliferation and tissue remodelling. Each is tightly regulated since insufficient or excessive activation can result in, respectively, chronic wounds and fibrotic tissue, both of which can impair organ function. In PFCD, the outcomes of wound repair include restitution (complete healing), epithelialisation and chronic wounds. Treatment of PFCD should take into consideration the distinct phases of wound repair. Therefore, the ability to differentiate between each phase of wound repair and their outcomes may help physicians deliver the most effective treatment strategy at the most appropriate time.

This review provides a comprehensive overview of the phases of wound repair and specific treatment strategies for each to provide clinicians with a rational framework for managing PFCD.

Inflammatory bowel disease (IBD), encompassing ulcerative colitis and Crohn's disease, is a group of chronic, immune-mediated disorders of the gastrointestinal tract that present substantial clinical challenges owing to their complex pathophysiology and tendency to relapse. A treat-to-target approach is recommended, involving iterative treatment adjustments to achieve clinical response, reduce inflammatory markers and achieve long-term goals such as mucosal healing. Lifelong medication is often necessary to manage the disease, maintain remission and prevent complications. The therapeutic landscape for IBD has evolved substantially; however, a ceiling on therapeutic efficacy remains and surgery is sometimes required (owing to uncontrolled disease activity or complications). Effective IBD management involves comprehensive care, including medication adherence and a collaborative clinician-patient relationship. This Review discusses current therapeutic options for IBD, detailing mechanisms of action, efficacy, safety profiles and guidelines for use of each drug class. We also explore emerging therapies and the role of surgery. Additionally, the importance of a multidisciplinary team and personalized care in managing IBD is emphasized, advocating for patient empowerment and involvement in treatment decisions. By synthesizing current knowledge and emerging trends, this Review aims to equip healthcare professionals with a thorough understanding of therapeutic options for IBD, enhancing informed, evidence-based decisions in clinical practice.

Crohn's disease (CD) causes gastrointestinal symptoms (i.e., diarrhea and abdominal pain), systemic symptoms (i.e., fatigue, anemia, weight loss, and fever), and perianal fistulas that produce anal pain. Because of the frequent occurrence of diarrhea and ulcers in the rectum, CD is often exacerbated by perianal abscesses and/or fistulas. Perianal fistulizing CD (PFCD) has an unknown etiology and recurring symptoms such as pain and discharge, which seriously affects the patient's quality of life (QOL). In the past, radical surgery was performed for PFCD, but due to the risk of anal sphincter impairment, conservative therapy using antibiotics and immunosuppressive medications is currently the first treatment option. PFCD management has greatly improved with the use of biologics such as the antitumor necrosis factor alpha (TNF-α) antibodies infliximab and adalimumab. In this review, the results of the administration of anti-TNF-α (certolizumab pegol), anti-interleukin-12/23 (ustekinumab), and anti-α4β7 integrin antibodies (vedolizumab) were evaluated. Our investigation showed that these medications may be effective for maintenance therapy to prevent the recurrence of anal fistulas. In addition to biologics, molecular target drugs and even regenerative medicine using mesenchymal stem cells have been introduced to further expand the treatment options for consideration by medical personnel. We herein discuss the management of PFCD by focusing on studies conducted in the United States and Europe where researchers used recommended guidelines and consensus statements to evaluate the efficacy of each medication and published their findings in peer-reviewed journals.

Extensive research has investigated the etiology of Crohn's disease (CD), encompassing genetic predisposition, lifestyle factors, and environmental triggers. Recently, the gut microbiome, recognized as the human body's second-largest gene pool, has garnered significant attention for its crucial role in the pathogenesis of CD. This paper investigates the mechanisms underlying CD, focusing on the role of 'creeping fat' in disease progression and exploring emerging therapeutic strategies, including fecal microbiota transplantation, enteral nutrition, and therapeutic diets. Creeping fat has been identified as a unique pathological feature of CD and has recently been found to be associated with dysbiosis of the gut microbiome. We characterize this dysbiotic state by identifying key microbiome-bacteria, fungi, viruses, and archaea, and their contributions to CD pathogenesis. Additionally, this paper reviews contemporary therapies, emphasizing the potential of biological therapies like fecal microbiota transplantation and dietary interventions. By elucidating the complex interactions between host-microbiome dynamics and CD pathology, this article aims to advance our understanding of the disease and guide the development of more effective therapeutic strategies for managing CD.

Crohn's perianal fistula healing rates remain low. We evaluated the efficacy of a protocolized multidisciplinary treatment strategy optimizing care in adults with Crohn's perianal fistulas.

A new treatment strategy was established at a single tertiary center. The strategy comprised 3 dynamic stages of care directed toward achieving and maintaining fistula healing. Stage A, active disease, focused on early commencement and proactive escalation of biologic therapies and structured surgical reviews ensuring adequate fistula drainage and conditioning. Stage B, optimized disease with a seton in situ, focused on consideration for seton removal and appropriateness of definitive surgical closure and/or ablative techniques. Stage C, healed disease, focused on proactive care maintenance. Sixty patients were sequentially enrolled and prospectively followed for ≥12 months. Endpoints included clinical healing and radiologic remission in those with clinically active fistulas, and relapse in those with healed fistulas.

At baseline, 52% (n = 31) and 48% (n = 29) had clinically active and healed fistulas, respectively. For patients with clinically active fistulas, 71% achieved clinical healing after 22 months, with estimated healing rates of 39% and 84% at 1 and 2 years, respectively. Radiologic remission was achieved in 25%, significantly higher than baseline inclusion rates of 6%. For patients with healed fistulas, 7% experienced clinical relapse after 23 months, with no significant change in radiologic remission, 80% versus 86% at baseline.

A protocolized treatment strategy proactively optimizing care resulted in high rates of clinical healing and improved radiologic remission of Crohn's perianal fistulas. Controlled-matched studies are needed.

In contrast to previous network meta-analysis using classical frequentist methods, we evaluated the efficacy and safety of six frequently-used biologics through a Bayesian method.

Web of Science, Scopus, CENTRAL, ClinicalTrials.gov and ICTRP were searched to collect randomized controlled trials (RCTs) in adults with moderate-to-severe Crohn's disease, comparing Infliximab, Adalimumab, Certolizumab pegol, Ustekinumab, Risankizumab, or Vedolizumab, relative to placebo or an active comparator for induction of clinical response (two different definitions) and maintenance of clinical remission. A random-effects model was performed with rankings according to the surface under cumulative ranking curve (SUCRA) probability. Finally, we completed sensitivity and consistency analyses, and evaluated the certainty of evidence through GRADE working group guidance.

We identified 22 and 20 RCTs for induction and maintenance therapy, respectively. Infliximab combined with azathioprine was most effective for inducing clinical response in TNF (tumor necrosis factor) antagonist-naïve patients. For TNF antagonist-experienced patients, Ustekinumab (SUCRA 86.19) and Risankizumab (SUCRA 62.56) have the largest SUCRA in induction of clinical response. Risankizumab has the lowest risk of adverse events (SUCRA 84.81), serious adverse events (SUCRA 94.23), and serious infections (SUCRA 79.73) in induction therapy. Adalimumab and the 10 mg/kg regimen of Infliximab rank highest for maintaining clinical remission.

This analysis suggests that Infliximab in combination with azathioprine may be preferred biologic agents for induction therapy in TNF antagonist-naïve patients. For TNF antagonist-experienced patients, Ustekinumab and Risankizumab may be preferred biologic agents for induction therapy. Risankizumab potentially has the lowest safety risk worth exploring in induction therapy. Adalimumab and the 10 mg/kg regimen of Infliximab have maintenance efficacy benefits for responders to induction therapy.

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=458609, Identifier CRD42023458609.

The treatment options for chronic inflammatory bowel diseases (IBD) have been greatly expanded due to a better understanding of the underlying pathogenesis. A total of five classes of advanced treatment are available.

A practical overview of advanced treatment of IBD.

Narrative review.

Advanced treatments are indicated for moderate to severe IBD. A timely use is recommended to achieve better response rates and to avoid irreversible bowel damage. Tumor necrosis factor (TNF) inhibitors and Janus kinase (JAK) inhibitors have a broad efficacy, also for extraintestinal disease manifestations. The risk of reactivation of varicella zoster virus is increased with JAK inhibitors. In high-risk patients and an age >65 years there is possibly a moderately elevated cardiovascular risk and neoplastic side effects. The integrin alpha4beta7 inhibitor vedolizumab and the interleukin (IL) 12 and 23 inhibitor ustekinumab have very good safety profiles. Selective IL-23 inhibitors are sometimes superior to ustekinumab with comparable safety profiles with respect to efficacy. The sphingosine-1-phosphate receptor modulators ozanimod and etrasimod are approved for oral treatment of ulcerative colitis. The treatment success of the medications remains still limited and a minority of patients will not respond to every individual treatment. Thus, sequential administration of several treatments is often needed. Due to the lack of comparative studies, the personalized choice, sequence and decision for treatments are usually based on personal experience and should take patient preferences, efficacy, safety and individual patient profiles into consideration.

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.

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.

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).

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.

Herein, we described a case of small bowel Crohn's disease with recurrent, unexplained fevers, pain in the right lower back, hip, and groin area over 20 months. The patient did not present any gastrointestinal symptoms and colonoscopy showed no abnormalities. Imaging revealed a liver abscess and multiple lesions with pneumatosis in the muscles of the right lower back region. Initially, disseminated infection was suspected and the antibiotics was administered without success. Subsequently, Magnetic resonance (MR) enterography suggested the possibility of a small bowel fistula which was confirmed during exploratory laparotomy. Inflammation was prominent in a 27-cm segment starting from 30-cm proximal to the ileocecal junction. The segment was resected and pathological examination confirmed Crohn's disease. Postoperatively, mesalazine was administered, but showed limited efficacy. After modifying the treatment plan to infliximab and azathioprine, the patient was symptom-free and no obvious inflammation was found in the colonoscopy reexamination.

In order to better understand the incidence of IBD in China, we conducted a retrospective study to analyze the clinical information of IBD patients in Shanghai, China.

From January 2014 to December 2021, patients diagnosed with IBD and hospitalized were enrolled. The demographic, clinical features, symptoms, laboratory tests and treatment data of the patients were retrospectively analyzed.

This study included 454 patients with UC and 333 patients with CD. The rate of hospitalization for IBD showed an escalating trend throughout the period, the number of hospitalizations was significantly higher in CD patients than in UC patients. The male patients had more complications than the female patients (p < 0.05). Definitive diagnosis of IBD in older patients was difficult (p < 0.05), and misdiagnosis was common. The incidence of complications and extraintestinal manifestations in elderly IBD patients was lower, but the incidence of intestinal obstruction was higher (p < 0.05). There was a significant correlation between the disease activity grades of IBD and fibrinogen, hemoglobin, albumin. Elderly IBD patients presented with lower rates of immunosuppressant, biologics, surgery or enteral nutrition.

This study analyzed the incidence, characteristics and treatment of IBD patients in Shanghai, and provided evidence-based evidence for doctors to more effectively diagnose and treat IBD in the future.

Nowadays, there is a clear need for new viable therapeutic options to face complex perianal Crohn's disease (PCD). Results of our previous pilot study demonstrated the efficacy and safety of local injection of autologous microfragmented adipose tissue (MFat) in this setting. This study aims to evaluate the long-term follow-up results in the same cohort of patients.

Data on clinical and radiological remission and surgical recurrence rates were prospectively collected on the 15 patients with complex fistulizing PCD refractory to combined bio-surgical therapy, originally treated with local MFat injection, with a mean 6.7 years follow-up.

In our previous study, at 24-week follow-up, combined remission was reported in 66.7% of patients, while clinical remission was achieved in 93% of cases. At a 6.7-year follow-up, 9 of the 10 healed patients maintained remission. The patient with recurrence was successfully reoperated. Three out of 5 patients who failed primary combined remission were retreated, with 2 obtaining combined remission and 1 failing. One patient refused any subsequent treatment due to good quality of life. The last patient presented delayed healing at a 1-year follow-up. Overall success rate after rescue therapy at the final follow-up reached 86.6%. Safety was maintained throughout all follow-up periods.

This is the longest follow-up published trial on MFat injection for PCD. Our results show that patients who achieved closure in the first 24 weeks sustained response at long-term evaluation. In addition, there may be a rationale in repeating treatment as rescue therapy in not responding to patients.

This study aimed to evaluate the impact of the WSES-AAST guidelines in clinical practice and to investigate the knowledge, attitudes, and practices of emergency surgeons in managing the complications of ulcerative colitis (UC) and Crohn's disease (CD).

The MIBODI survey is a cross-sectional study among WSES members designed as an international web-based survey, according to the Checklist for Reporting Results of Internet E-Surveys, to collect data on emergency surgeons' knowledge, attitudes, and practices concerning the management of patients presenting with acute complications of CD and UC. The questionnaire was composed of 30 questions divided into five sections: (1) demographic data, (2) primary evaluation, (3) non-operative management, (4) operative management, and (5) perianal sepsis management.

Two hundred and forty-two surgeons from 48 countries agreed to participate in the survey. The response rate was 24.2% (242/1000 members on WSES mail list). Emergency surgeons showed high adherence to recommendations for 6 of the 21 assessed items, with a "correct" response rate greater than or equal to 60%, according to WSES-AAST recommendations. Nine critical issues were highlighted, with correct answers at a rate of less than 50%.

Inflammatory bowel disease is a complex disease that requires a multidisciplinary approach with close collaboration between gastroenterologists and surgeons. Emergency surgeons play a crucial role in managing complications related to IBD. One year after publication, the MIBODI study showed significant global implementation of the WSES-AAST guidelines in clinical practice, offering an imperative tool in the improved management of IBD in emergency and urgent settings.

Fistulizing Crohn's Disease (fCD) affects up to 50% of people with Crohn's Disease over their lifetime. Despite this high prevalence, the burden of disease, treatment and natural history in the current biologic era are poorly described. This study explores demographic, disease and treatment factors in a real-world Australasian cohort.

A large real-world cohort of people with inflammatory bowel disease under routine care was interrogated in August 2023. Current fCD was defined as fistula(e) on most recent clinical, radiologic or endoscopic investigation; prior fCD was defined as the resolution of fistula(e) on most recent documentation.

Of 3075 people with Crohn's Disease, 7.4% had current and 10.1% prior fCD (n = 224 & 311). Most patients were in Australia (77%), where 19.3% had current or previous fCD compared to 11% in New Zealand (P < .001). Patients with current or previous fCD were younger compared to those without (P = .003 & P < .001). Males were more commonly affected (P = .021). Current or prior fCD were more likely to be on biologic therapy (P < .001), with anti-tumor necrosis factor agents most frequently utilized. Conversely, those without fCD were more likely on Ustekinumab or Vedolizumab compared to current and prior fCD groups. People with fistulizing disease had higher hospitalization rates, while the prior fCD cohort had longer hospital admissions and more frequently required surgical intervention.

People with fCD used more health-care resources, making this an important area for further research into care gaps to improve outcomes and optimal treatment approaches.

This article discusses the literature review article by Pacheco et al published in July 2024; the authors provided good reviews of perianal Crohn's disease (CD), and challenges faced by clinicians in the management. CD, characterized by its chronic and relapsing nature, is an idiopathic condition that can involve any segment of the gastrointestinal tract. Perianal disease impacts up to 40% of patients with CD, with perianal fistulas constituting up to 80% of perianal lesions. Perianal CD can be highly incapacitating and profoundly diminish the overall well-being of patients. The management focuses on controlling the perianal sepsis and treating luminal CD. Biologics are crucial to the treatment approach, and results have been encouraging. The surgery focuses on controlling the sepsis, with more definitive treatments being fistula surgery, fecal diversion, and proctectomy as the last resort. This manuscript briefly describes the burden of CD, the challenges posed by perianal CD, and the role of different treatment modalities from colorectal surgeon's perspective.

The use of infliximab to treat Crohn's disease patients has been evaluated for decades. The current work aimed to identify the historical roots of this research topic.

The literature database Web of Science Core Collection was searched to identify relevant papers. Cited reference analysis on the identified literature set was performed using CRExplorer, a dedicated bibliometric software. The disruption index was computed with an automated routine described by Leydesdorff and Bornmann, which is freely available online. Based on data from citation count and reference list, the disruption index can range from -1 to +1, with -1 meaning a continuity from existing research and +1 meaning a disruption.

This analysis successfully identified key references dealing with infliximab use on Crohn's disease patients, such as the original report that introduced the Crohn's Disease Activity Index (CDAI) in 1976, the first case series reporting a favourable outcome of infliximab infusion on 10 patients published in 1995, the first randomized controlled trial published in 1997, the ACCENT I and ACCENT II trials published in 1999 and 2002, and a couple of European consensus guidelines on the diagnosis and management of Crohn's disease.

Cited reference analysis could reveal the historical origins of the use of infliximab in treating Crohn's disease. Highly cited references included CDAI, important early clinical studies, and European consensus guidelines. The important cited references identified by the analysis provided solid foundation to support subsequent research.

Infliximab (IFX) is a recombinant DNA-derived chimeric IgG monoclonal antibody protein that inhibits tumor necrosis factor alpha (TNF-α). IFX, like other agents derived from foreign proteins, can cause infusion reactions both during and after the infusion. The incidence of infusion reactions ranges between 0% and 15% in pediatric patients. The potential underlying mechanisms for these reactions may include anaphylaxis and anaphylactoid reactions, cytokine release syndrome, serum sickness-like reactions, and the development of antibodies against IFX. Several precautions can help reduce the risk of a new infusion reaction, such as a gradual increase in the infusion rate, scheduled infusions, and administering premedication or immunomodulators alongside IFX. Acute mild to moderate reactions often resolve spontaneously after a temporary cessation of the infusion or reduction in the infusion rate. Strategies like graded dose challenges and premedication can be utilized to prevent recurrence. In cases of severe reactions, desensitization or switching to an alternative biologic may be considered. This article aims to review the most recent guidelines for managing IFX-related infusion reactions in pediatric patients with inflammatory bowel disease (IBD), relying on the best available evidence.

Perianal fistulas are a debilitating complication of Crohn's disease (CD). Due to unknown reasons, CD-associated fistulas are in general more difficult to treat than cryptoglandular fistulas (non-CD-associated). Understanding the immune cell landscape is a first step towards the development of more effective therapies for CD-associated fistulas. In this work, we characterized the composition and spatial localization of disease-associated immune cells in both types of perianal fistulas by high-dimensional analyses.

We applied single-cell mass cytometry (scMC), spectral flow cytometry (SFC), and imaging mass cytometry (IMC) to profile the immune compartment in CD-associated perianal fistulas and cryptoglandular fistulas. An exploratory cohort (CD fistula, n = 10; non-CD fistula, n = 5) was analyzed by scMC to unravel disease-associated immune cell types. SFC was performed on a second fistula cohort (CD, n = 10; non-CD, n = 11) to comprehensively phenotype disease-associated T helper (Th) cells. IMC was used on a third cohort (CD, n = 5) to investigate the spatial distribution/interaction of relevant immune cell subsets.

Our analyses revealed that activated HLA-DR+CD38+ effector CD4+ T cells with a Th1/17 phenotype were significantly enriched in CD-associated compared with cryptoglandular fistulas. These cells, displaying features of proliferation, regulation, and differentiation, were also present in blood, and colocalized with other CD4+ T cells, CCR6+ B cells, and macrophages in the fistula tracts.

Overall, proliferating activated HLA-DR+CD38+ effector Th1/17 cells distinguish CD-associated from cryptoglandular perianal fistulas and are a promising biomarker in blood to discriminate between these 2 fistula types. Targeting HLA-DR and CD38-expressing CD4+ T cells may offer a potential new therapeutic strategy for CD-related fistulas.

The efficacy of ustekinumab and vedolizumab for treating complex perianal fistula in Crohn's disease has been barely studied. We aimed to assess treatment persistence, clinical remission, and safety of these drugs in this context.

Crohn's disease patients who had received ustekinumab or vedolizumab for the indication of active complex perianal fistula, were included. Clinical remission was defined according to Fistula Drainage Assessment Index (no drainage through the fistula upon gentle pressure) based on physicians' assessment.

Of 155 patients, 136 received ustekinumab, and 35 vedolizumab (16 received both). Median follow-up for ustekinumab was 27 months. Among those on ustekinumab, 54 % achieved remission, and within this group, 27 % relapsed during follow-up. The incidence rate of relapse was 11 % per patient-year. Multivariate analysis found no variables associated with treatment discontinuation or relapse. Median follow-up time for patients receiving vedolizumab was 19 months. Remission was achieved in 46 % of the patients receiving vedolizumab, and among them, 20 % relapsed during follow-up. The incidence rate of relapse was 7 % per patient-year. Adverse events were mild in 6 % on ustekinumab and 8 % on vedolizumab.

Ustekinumab and vedolizumab appear effective, achieving remission in around half of complex perianal fistula patients, with favorable safety profiles.

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.

In this editorial we comment on the article by Pacheco et al published in a recent issue of the World Journal of Gastroenterology. We focus specifically on the burden of illness associated with perianal fistulizing Crohn's disease (PFCD) and the diagnostic and therapeutic challenges in the management of this condition. Evolving evidence has shifted the diagnostic framework for PFCD from anatomical classification systems, to one that is more nuanced and patient-focused to drive ongoing decision making. This editorial aims to reflect on these aspects to help clinicians face the challenge of PFCD in day-to-day clinical practice.

Infliximab (IFX) has transformed the management of inflammatory bowel diseases (IBD). While intravenous (IV) IFX has been effective, a subcutaneous (SC) formulation offers advantages in convenience and cost. However, there is lack of evidence regarding the transition from IV to SC-IFX, especially for patients with inadequate responses. This study investigates the effectiveness of switching from IV to SC-IFX in patients with inadequate responses during IV maintenance therapy. A retrospective study enrolled IBD patients who transitioned to SC-IFX after demonstrating inadequate responses during IV maintenance therapy. The study collected data of demographics of patients and dose and therapies administered prior to the IV-IFX. Primary outcomes included improvements in C-reactive protein (CRP) or fecal calprotectin (FC) levels. This study evaluated the trough levels and its differences between pre- and post-switching. Among 44 patients included, 10 exhibited CRP elevation before the switch, with 6 showing normalization post-switch. Similarly, 42 patients had elevated FC levels pre-switch, with 26 experiencing reductions post-switch. Trough levels increased after the switch. However, there were no significant differences between responders and non-responders. This study is the first study to investigate the transition therapy of IV to SC-IFX in patients with inadequate response. This suggests that SC-IFX could be a viable alternative in the management of IBD. However, further research is necessary to evaluate its efficacy in a larger population of patients who exhibit inadequate responses during IV-IFX maintenance therapy.

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.

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).

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

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.

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.

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.

Crohn's disease (CD) has a progressive nature and commonly perianal involvement. The aim of this study is to assess the prevalence, surgical treatment, and outcome of perianal fistulizing CD with associated risk factors in a large Chinese cohort.

Hospitalized patients diagnosed with CD in our center were consecutively enrolled between January 2000 and December 2018. Transition of disease behavior was classified according to the presence or absence of penetrating behavior (B3 in the Montreal classification) at diagnosis and at a median follow-up of 102 months.

A total of 504 patients were included, of whom 207 (41.1%) were classified as B3 and 348 (69.0%) as L2/3 at follow-up. Transition of behavior to B3 was observed in 86 patients (17.1%). The incidence of perianal fistulizing lesions was 10.9% at 10 years with a final prevalence of 27.0% (n = 136) at the end of follow-up. Multivariate Cox regression identified independent risks of perianal fistulizing lesions for persistent B3 (hazard ratio, 4.72; 95% confidence interval, 1.91-11.66) and behavior transition of progressed to B3 (hazard ratio, 9.90; 95% confidence interval, 4.60-21.33). Perianal surgical treatments were performed in 104 patients (20.6%). Thirty-six cases (7.1%) were refractory, and it is independently associated with behavior of persistent B3 (P= 0.011).

Perianal fistulizing lesions occurred frequently in Chinese CD patients. Its incidence and refractory outcome were closely associated with the penetrating CD behavior. An additional risk of perianal fistulizing lesions was indicated for CD patients with behavior of progressing to B3, suggesting further attention.

Introduction: Therapeutic drug monitoring (TDM) has proven to be a valuable strategy for optimizing biologic therapies, among which are anti-tumor necrosis factor (anti-TNF) treatments in inflammatory bowel disease (IBD). In particular, reactive TDM has been shown to manage treatment failures more cost-effectively than empirical dose adjustments for anti-TNF drugs. However, several challenges currently impede the widespread adoption of TDM in clinical practice, particularly addressing the delay between sample collection and result availability. To overcome this limitation, the use of point-of-care technology tests (POCTs) is a potential solution. Point-of-care technology tests are medical diagnostic tests performed at the site of patient care to provide immediate results, allowing for quicker decision-making and treatment. The current standard of care (SOC) for drug level measurement relies on the enzyme-linked immunosorbent assay (ELISA), a method that is time-consuming and requires specialized personnel. This study aims to evaluate a novel, user-friendly, and efficient POCT method (ProciseDx Inc.) and compare its performance with the SOC ELISA in assessing infliximab and adalimumab levels in blood samples from IBD patients. Methods: In this prospective, single-center study, we collected blood samples from IBD patients, both CD and UC, receiving infliximab (87 IBD patients; 50% UC and 50% CD) or adalimumab (60 patients; 14% UC and 48% CD) and we analyzed the blood's drugs levels using both the ProciseDx Analyzer POC and the SOC ELISA. We examined the correlation between the two methods using statistical analyses, including the Deming regression test. Additionally, we assessed the ease of use, turnaround time, and overall practicality of the POCT in a clinical setting. Results: The ProciseDx test demonstrated a strong correlation with the SOC ELISA for measuring both infliximab and adalimumab levels. In particular, the overall correlation between the ProciseDx POCT and the ELISA assessments showed an r coefficient of 0.83 with an R squared value of 0.691 (95% CI 0.717-0.902) for IFX measurements, and an r coefficient of 0.85 with an R squared value of 0.739 (95% CI 0.720-0.930). Conclusions: the ProciseDx POC test offers significantly faster turnaround times and is more straightforward to use, making it a viable alternative for routine clinical monitoring. Despite its promising potential, further refinement and validation of the ProciseDx test are necessary to ensure its effectiveness across diverse patient populations and clinical settings. Future research should focus on optimizing the POC tests' performance and evaluating its long-term impact on IBD management.

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.

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.

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.

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).

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.