Monoclonal Antibodies Against Mature Interleukin-18 Ameliorate Colitis and Repair Goblet Cell Function.

BACKGROUND: Numerous biological interventions and small molecules are used to treat Crohn's disease; however, the effectiveness of these treatments varies largely. Non-responsiveness to biological therapies is associated with interleukin (IL)-18 gene polymorphisms and high IL-18 expression has been implicated in the pathogenesis of Crohn's disease. AIMS: The aim of this study was to elucidate the expression of precursor and mature IL-18 in patients with Crohn's disease who exhibited varied responses to cytokine-targeted treatments and determine whether selective inhibition of mature IL-18 offers a novel therapeutic avenue. METHODS: We generated a monoclonal antibody that specifically recognizes the neoepitope of caspase-cleaved mature IL-18. Expression of precursor and mature IL-18 was analyzed in patients with Crohn's disease. Anti-mature IL-18 monoclonal antibodies were intraperitoneally administered in an acute colitis mouse model, and the disease activity index, body weight loss, tissue pathology, proinflammatory cytokine expression, goblet cell function, and microbiota composition were assessed. RESULTS: Precursor and mature IL-18 expression was upregulated and goblet cell function was impaired in patients with Crohn's disease who were unresponsive to biological therapies. Administration of anti-mature IL-18 antibodies ameliorated induced colitis by repairing goblet cell function and restoring the mucus layer. CONCLUSIONS: The newly developed monoclonal antibody holds promise as a therapeutic alternative for Crohn's disease.

Monoclonal Antibody Against Mature Interleukin-18 Ameliorates Colitis in Mice and Improves Epithelial Barrier Function.

BACKGROUND: Antitumor necrosis factor (TNF)-α antibodies have improved the outcome of inflammatory bowel disease (IBD); but half of patients remain unresponsive to treatment. Interleukin-18 (IL-18) gene polymorphism is associated with resistance to anti-TNF-α antibodies, but therapies targeting IL-18 have not been clinically applied. Only the mature protein is biologically active, and we aimed to investigate whether specific inhibition of mature IL-18 using a monoclonal antibody (mAb) against a neoepitope of caspase-cleaved mature IL-18 could be an innovative treatment for IBD. METHODS: The expression of precursor and mature IL-18 in patients with UC was examined. Colitis was induced in C57/BL6 mice by administering dextran sulfate sodium (DSS), followed by injection with anti-IL-18 neoepitope mAb. Colon tissues were collected and subjected to histological analysis, immunohistochemistry, immunoblotting, and quantitative polymerase chain reaction. Colon epithelial permeability and microbiota composition were analyzed. RESULTS: Mature IL-18 expression was elevated in colon tissues of patients with active ulcerative colitis. Administration of anti-IL-18 neoepitope mAb ameliorated acute and chronic DSS-induced colitis; reduced interferon-γ, TNF-α, and chemokine (CXC motif) ligand-2 production and epithelial cell permeability; promoted goblet cell function; and altered the intestinal microbiome composition. The suppressive effect of anti-IL-18 neoepitope mAb was superior to that of anti-whole IL-18 mAb. Furthermore, combination therapy with anti-TNF-α Ab suppressed acute and chronic colitis additively by suppressing cytokine expressions and reducing cell permeability by upregulating claudin1 and occludin expression. CONCLUSIONS: Anti-IL-18 neoepitope mAb ameliorates acute and chronic colitis, suggesting that this mAb will be an innovative therapeutic option for IBD.

We investigate a novel monoclonal antibody that specifically recognizes a neoepitope of caspase-cleaved IL-18 and alleviates dextran sulfate sodium-induced colitis by suppressing the secretion of inflammatory cytokines, improving intestinal epithelial permeability, promoting goblet cell function, and regulating intestinal microbiota.

The establishment of a regression model from four modes of ultrasound to predict the activity of Crohn's disease.

To establish a multi-parametric regression model from four modes of ultrasound to predict the activity of Crohn's disease (CD) noninvasively. Score of 150 of the Crohn's Disease Activity Index (CDAI) was taken as the cut-off value to divide the involved bowel segments of 51 patients into the active and inactive group. Eleven parameters from four modes of ultrasound (B-mode ultrasonography, color Doppler flow imaging, contrast-enhanced ultrasonography and shear wave elastography) were compared between the two groups to investigate the relationship between multimodal ultrasonic features and CD activity. P < 0.05 was considered statistically significant. Parameters with AUC larger than 0.5 was selected to establish the prediction model of CDAI. Totally seven ultrasound parameters (bowel wall thickness, mesenteric fat thickness, peristalsis, texture of enhancement, Limberg grade, bowel wall perforation and bowel wall stratification) were significantly different between active and inactive group. A regression model was established based on the seven parameters as followed: CDAI = 211.325 + 3.186BWT - 53.003BWS + 6.280BWP + 0.392MFT + 22.239PS + 79.012LG + 72.793TE. (R2 = 0.72, P = 0.037). The multimodal ultrasound parametric regression model was designed to predict CDAI score invasively. The model has the potential to provide an alternative method for quantifying the CD activity.

Transient Receptor Potential Channels and Inflammatory Bowel Disease.

The transient receptor potential (TRP) cation channels are present in abundance across the gastrointestinal (GI) tract, serving as detectors for a variety of stimuli and secondary transducers for G-protein coupled receptors. The activation of TRP channels triggers neurogenic inflammation with related neuropeptides and initiates immune reactions by extra-neuronally regulating immune cells, contributing to the GI homeostasis. However, under pathological conditions, such as inflammatory bowel disease (IBD), TRP channels are involved in intestinal inflammation. An increasing number of human and animal studies have indicated that TRP channels are correlated to the visceral hypersensitivity (VHS) and immune pathogenesis in IBD, leading to an exacerbation or amelioration of the VHS or intestinal inflammation. Thus, TRP channels are a promising target for novel therapeutic methods for IBD. In this review, we comprehensively summarize the functions of TRP channels, especially their potential roles in immunity and IBD. Additionally, we discuss the contradictory findings of prior studies and offer new insights with regard to future research.

COVID-19 With Preexisting Hypercoagulability Digestive Disease.

The outbreak of coronavirus disease of 2019 (COVID-19) has become a global public health and economic crisis. The advent of hypercoagulability and thrombotic complications can substantially influence the prognosis of COVID-19 patients. In this review, we elaborate on the clinical findings, potential underlying pathogenesis, and therapeutic strategy of hypercoagulability and thromboembolism in COVID-19, particularly focusing on the COVID-19 patients with preexisting digestive hypercoagulability disease.

High level of IgG4 as a biomarker for a new subset of inflammatory bowel disease.

The roles of B and plasma cells in the pathogenesis of inflammatory bowel disease (IBD) are largely unrevealed. Data on the characteristics of IgG4 in patients with IBD are scarce. In this case-control study, serum IgG4 levels were comparable between patients with IBD and healthy individuals, whereas patients with IBD had dramatically higher mucosal IgG4 counts than healthy individuals. In patients with UC, mucosal IgG4 counts were positively correlated with serum IgG4 levels, serum IgG4/IgG ratios, and the Mayo Index; serum IgG4 levels and IgG4/IgG ratios were associated with a history of intestinal surgery and medications. A significant mucosal IgG4 count was found in 33.3% of patients with IBD, whereas, elevated serum IgG4 levels were found in only 9.9% of patients with IBD. Lesions were more severe and extensive in IBD patients with high levels of serum and mucosal IgG4. High levels of serum and mucosal IgG4 decreased after treatment with glucocorticoids or other immunosuppressants. High IgG4 level may be a biomarker for a new subset of IBD. More studies are warranted to explore this new subset of IBD for personalized therapy in the future.

Primary Intestinal Epstein-Barr Virus-associated Natural Killer/T-cell Lymphoproliferative Disorder: A Disease Mimicking Inflammatory Bowel Disease.

BACKGROUND AND AIMS: Primary intestinal Epstein-Barr virus [EBV]-associated natural killer/T-cell lymphoproliferative disorder [PIEBV+ NK/T-LPD] is a rare clinical entity, which is difficult to differentiate from inflammatory bowel disease [IBD]. We present a series of Chinese patients with PIEBV+ NK/T-LPD to increase awareness among clinicians of this condition. METHODS: Patients diagnosed with PIEBV+ NK/T-LPD at West China hospital between 2014 and 2016 were included. Clinical and histopathological characteristics were reviewed, and key aspects of differential diagnosis were presented. RESULTS: Twelve patients diagnosed with PIEBV+ NK/T-LPD were identified. Initial symptoms included intermittent fever [11/12 patients], abdominal pain [9/12], haematochezia [8/12], and diarrhoea [3/12]. Main endoscopic findings included multisegmental irregular, variable-sized ulcers, isolated giant ulcers, and diffuse inflammation. Colon and ileocaecum were mainly affected in 11 patients. The main PIEBV+ NK/T-LPD immunophenotypic profile of the infiltrating cells was CD3ε-positive NK/T cells characterised by positive T-cell intracellular antigen-1 and granzyme B, with CD5 deletion. In situ hybridisation was positive for EBV-encoded small RNAs 1/2 in all patients. Eleven patients were misdiagnosed with ulcerative colitis [4/11], Crohn's disease [4/11], or tuberculosis [TB, 3/11], owing to the similar endoscopic and histopathological features. The mean number of endoscopic procedures performed before reaching the diagnosis of PIEBV+ NK/T-LPD was 3.58; in four patients, the diagnosis was confirmed only after surgical resection following complications. CONCLUSIONS: PIEBV+ NK/T-LPD may be difficult to differentiate from IBD or TB owing to overlapping endoscopic and pathological findings. Early identification of EBV reactivation in tissue samples is essential for the accurate diagnosis.

Chinese research into severe ulcerative colitis has increased in quantity and complexity.

AIM: To investigate the current state of research output from Chinese studies into severe ulcerative colitis (SUC) using a bibliometric analysis of publications. METHODS: The contents of the Chinese periodical databases WANFANG, VIP, and China National Knowledge Infrastructure were searched for all papers regarding UC or SUC published in last the 15 years (from 2001 to 2015). The number of publications in each year was recorded to assess the temporal trends of research output. All SUC related publications were downloaded and the complexity of this research was evaluated with methods described previously. The number of patients with SUC reported each year was recorded and their clinical characteristics were analyzed using information available in the relevant papers. RESULTS: There were 13499 publications regarding UC published in Chinese medical journals between 2001 and 2015, of which 201 focused on SUC. The number of publications increased rapidly with more than half of all papers being published in the most recent 5-year period. There was a significant increase in analytical studies and clinical trials over the study period (P < 0.01), with research into the management of SUC, included pharmacotherapy, nutrition support as well as surgery, predominating. Almost half (46.2%) of the observational analytical studies and clinical trials focused on Traditional Chinese Medicine, with little research on the efficacy of cyclosporin and infliximab in disease management. About 6222 patients with SUC were reported in the 201 SUC relevant papers, with a ratio of male/female of 1.38. The number of patients reported in each 5-year period significantly increased. The colectomy rate and short-term mortality rate were 7.7% and 0.8% respectively. The most commonly employed operation was total proctocolectomy with ileal pouch-anal anastomosis. CONCLUSION: The output and complexity of research related to SUC in China increased significantly over the previous 15 years, however few of these studies focused on salvage therapy.

Upregulation of the transient receptor potential vanilloid 1 in colonic epithelium of patients with active inflammatory bowel disease.

Transient receptor potential vanilloid 1 (TRPV1), the receptor of capsaicin, is a nonselective cation channel that is highly permeable to Ca2+. TRPV1 is involved in the activation of immune cells and plays a role in the pathogenesis of experimental colitis. The expression of TRPV1 in colonic epithelium and its correlation with inflammatory bowel disease (IBD) are poorly understood. In this study, colonic biopsies were taken from 60 patients with active inflammatory bowel disease, including 30 patients with ulcerative colitis (UC) and 30 patients with Crohn's disease (CD), and 30 healthy controls. Disease activity was assessed according to the Mayo score, Crohn's disease activity index (CDAI) score, and the level of C-reactive protein (CRP). The severity of histological inflammation was graded using a scoring system that was previously described. For immunohistochemical staining, sections were incubated with a polyclonal anti-TRPV1 antibody. Next, image analysis was performed to obtain an integrated option density (IOD) value to evaluate TRPV1 immunoreactivity of five random fields per section, which was 60973±29112 for the UC group, 61942±32083 for the CD group, and 35154±21293 for the control group. Our data showed that TRPV1 expression was significantly upregulated in colonic epithelium of IBD patients compared with controls (P<0.001). In addition, no significant differences were observed in TRPV1 expression between UC and CD groups (P>0.05). Although TRPV1 immunoreactivity was highly expressed on epithelial cells and infiltrating inflammatory cells in colonic biopsies of active IBD patients, TRPV1 expression did not significantly correlate with disease severity (P>0.05). Therefore, our findings suggested a crucial role of TRPV1 in inflammatory bowel disease, and indicated that further studies are clearly warranted to determine whether TRPV1 is a potential target for therapy.