The Use of Biologics in Patients with Inflammatory Bowel Disease and Primary Sclerosing Cholangitis

Inflammation drives pathogenesis of early intestinal failure-associated liver disease

Patients with intestinal failure who receive long-term parenteral nutrition (PN) often develop intestinal failure-associated liver disease (IFALD). Although there are identified risk factors, the early pathogenesis is poorly understood and treatment options are limited. Here, we perform a transcriptomic analysis of liver tissue in a large animal IFALD model to generate mechanistic insights and identify therapeutic targets. Preterm Yorkshire piglets were provided PN or bottle-fed with sow-milk replacer for 14 days. Compared to bottle-fed controls, piglets receiving PN developed biochemical cholestasis by day of life 15 (total bilirubin 0.2 vs. 2.9 mg/dL, P = 0.01). RNA-Seq of liver tissue was performed. Ingenuity Pathway Analysis identified 747 differentially expressed genes (343 upregulated and 404 downregulated) with an adjusted P < 0.05 and a fold-change of > |1|. Enriched canonical pathways were identified, demonstrating broad activation of inflammatory pathways and inhibition of cell cycle progression. Potential therapeutics including infliximab, glucocorticoids, statins, and obeticholic acid were identified as predicted upstream master regulators that may reverse the PN-induced gene dysregulation. The early driver of IFALD in neonates may be inflammation with an immature liver; identified therapeutics that target the inflammatory response in the liver should be investigated as potential treatments.

Ileal Pouch-anal Anastomosis in Primary Sclerosing Cholangitis-inflammatory Bowel Disease (PSC-IBD): Long-term Pouch and Liver Transplant Outcomes

OBJECTIVE

To compare the effect of liver transplantation (LT) on ileal pouch-anal anastomosis (IPAA) outcomes in patients with primary sclerosing cholangitis and inflammatory bowel disease (PSC-IBD).

BACKGROUND

Patients with PSC-IBD may require both IPAA for colitis and LT for PSC.

METHODS

Patients with PSC-IBD from out institutional pouch registry (1985-2022) were divided according to LT status and timing of LT (before and after IPAA) and their outcomes analyzed.

RESULTS

A total of 160 patients were included: 112 (70%) nontransplanted at last follow-up; 48 (30%) transplanted, of which 23 (14%) before IPAA and 25 (16%) after. Nontransplanted patients at IPAA had more laparoscopic procedures [37 (46%) vs 8 (18%), P =0.002] and less blood loss (median 250 vs 400 mL, P =0.006). Morbidity and mortality at 90 days were similar. Chronic pouchitis was higher in transplanted compared with nontransplanted patients [32 (67%) vs 51 (45.5%), P =0.03], but nontransplanted patients had a higher rate of chronic antibiotic refractory pouchitis. Overall survival was similar, but nontransplanted patients had more PSC-related deaths (12.5% vs 2%, P =0.002). Pouch survival at 10 years was 90% for nontransplanted patients and 100% for transplanted patients (log-rank P =0.052). Timing of LT had no impact on chronic pouchitis, pouch failure, or overall survival. PSC recurrence was 6% at 10 years. For transplanted patients, graft survival was similar regardless of IPAA timing.

CONCLUSIONS

In patients with PSC-IBD and IPAA, LT is linked to an increased pouchitis rate but does not affect overall and pouch survival. Timing of LT does not influence short-term and long-term pouch outcomes.

The Immunobiological Agents for Treatment of Antiglomerular Basement Membrane Disease

Combination therapy with glucocorticoids, cyclophosphamide, and plasmapheresis is recommended as the standard treatment for anti-glomerular basement membrane (anti-GBM) disease, but the prognosis of this disease remains poor. Several immunobiological agents have been administered or are expected to be useful for anti-GBM disease in light of refractory disease or the standard treatments' tolerability. Many data regarding the use of biologic agents for anti-GBM disease have accumulated, verifying the effectiveness and potential of biologic agents as a new treatment option for anti-GBM disease. Tumor necrosis factor (TNF) inhibitors were shown to be useful in animal studies, but these agents have no clinical use and were even shown to induce anti-GBM disease in several cases. Although the efficacy of the TNF-receptor antagonist has been observed in animal models, there are no published case reports of its clinical use. There are also no published reports of animal or clinical studies of anti-B-cell-activating factor, which is a member of the TNF family of agents. Anti-interleukin (IL)-6 antibodies have been demonstrated to have no effect on or to exacerbate nephritis in animal models. Anti-C5 inhibitor was observed to be useful in a few anti-GBM disease cases. Among the several immunobiological agents, only rituximab has been demonstrated to be useful in refractory or poor-tolerance patients or small uncontrolled studies. Rituximab is usually used in combination with steroids and plasma exchange and is used primarily as an alternative to cyclophosphamide, but there is insufficient evidence regarding the efficacy of rituximab for anti-GBM disease, and thus, randomized controlled studies are required.

Current Therapeutics in Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is an orphan, cholestatic liver disease that is characterized by inflammatory biliary strictures with variable progression to end-stage liver disease. Its pathophysiology is poorly understood. Chronic biliary inflammation is likely driven by immune dysregulation, gut dysbiosis, and environmental exposures resulting in gut-liver crosstalk and bile acid metabolism disturbances. There is no proven medical therapy that alters disease progression in PSC, with the commonly prescribed ursodeoxycholic acid being shown to improve liver biochemistry at low-moderate doses (15-23 mg/kg/day) but not alter transplant-free survival or liver-related outcomes. Liver transplantation is the only option for patients who develop end-stage liver disease or refractory complications of PSC. Immunosuppressive and antifibrotic agents have not proven to be effective, but there is promise for manipulation of the gut microbiome with fecal microbiota transplantation and antibiotics. Bile acid manipulation via alternate synthetic bile acids such as norursodeoxycholic acid, or interaction at a transcriptional level via nuclear receptor agonists and fibrates have shown potential in phase II trials in PSC with several leading to larger phase III trials. In view of the enhanced malignancy risk, statins, and aspirin show potential for reducing the risk of colorectal cancer and cholangiocarcinoma in PSC patients. For patients who develop clinically relevant strictures with cholestatic symptoms and worsening liver function, balloon dilatation is safer compared with biliary stent insertion with equivalent clinical efficacy.

Clinical course of inflammatory bowel disease and impact on liver disease outcomes in patients with autoimmune sclerosing cholangitis

BACKGROUND & AIMS

Autoimmune sclerosing cholangitis (ASC) is a childhood sclerosing cholangitis frequently associated with inflammatory bowel disease (IBD). We describe the IBD phenotype in ASC patients and associated liver disease outcomes.

METHODS

Single center retrospective observational review of ASC patients, with a control population of pediatric IBD. Demographic and clinical parameters were obtained. Clinical endpoints were escalation of IBD therapy (biologic or colectomy) and transplant-free survival.

RESULTS

In 93 ASC patients (53.8% female) and median follow up of 172 months: 70% had IBD, 25.8% underwent liver transplant. Median age at liver transplant was 21.7 years, at 131 months from ASC diagnosis. There was no association between presence of IBD and transplant-free survival, whilst those requiring second-line immunomodulators for ASC had poorer long-term liver prognosis. During follow-up 22 (33.8%) ASC-IBD required biologic or colectomy. On multivariate analysis ASC was associated with a lower risk of escalation of IBD therapy (HR 0.14, 95% CI 0.05-0.42; P=.001), including biologic therapy (HR 0.21, 95% CI 0.08-0.55, P=.002), but not colectomy on univariate analysis (HR 1.54, 95% CI 0.43-5.44, P=.51).

CONCLUSIONS

IBD is common in ASC and during longterm follow up a third of ASC-IBD required escalation of IBD therapy; however ASC-IBD was lower risk compared to IBD alone. IBD does not appear to impact on transplant-free survival in patients with ASC, however second-line immunomodulators for ASC are associated with poorer IBD and liver outcomes.

Choosing the right biologic for complications of inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic, inflammatory condition that involves the intestinal tract, and can also present with extra-intestinal manifestations (EIM). Choosing the right treatment for IBD is often nuanced and decisions can become even more complicated when a patient presents with or develops a complication of the disease.

AREAS COVERED

We aimed to provide an overview of the most common complications of IBD, specifically intestinal and EIM, and summarize the data regarding biologic therapy for treatment of these conditions. A comprehensive literature review was performed using PubMed and Medline databases to identify studies published in the English language relevant to the broad scope of this review.

EXPERT OPINION

There are still significant gaps in our understanding of the pathophysiology of IBD and its treatment, especially in regards to complications of the disease. As novel therapies continue to emerge for treatment of IBD, we feel concurrent examination of their impact on intestinal complications and EIM of IBD is important and should be a priority of future research.

TNF in the liver: targeting a central player in inflammation

Tumour necrosis factor-α (TNF) is a multifunctional cytokine. First recognized as an endogenous soluble factor that induces necrosis of solid tumours, TNF became increasingly important as pro-inflammatory cytokine being involved in the immunopathogenesis of several autoimmune diseases. In the liver, TNF induces numerous biological responses such as hepatocyte apoptosis and necroptosis, liver inflammation and regeneration, and autoimmunity, but also progression to hepatocellular carcinoma. Considering these multiple functions of TNF in the liver, we propose anti-TNF therapies that specifically target TNF signalling at the level of its specific receptors.

Revisiting an Expression Dataset of Discordant Inflammatory Bowel Disease Twin Pairs Using a Mutation Burden Test Reveals CYP2C18 as a Novel Marker

The aim of this study was to investigate the expression features of discordant inflammatory bowel disease (IBD) twin pairs to identify novel molecular features and markers. We collected an expression dataset of discordant twin pairs with ulcerative colitis and performed integrative analysis to identify the genetic-independent expression features. Through deconvolution of the immune cell populations and tissue expression specificity, we refined the candidate genes for susceptibility to ulcerative colitis. We found that dysregulated immune systems and NOD-related pathways were enriched in the expression network of the discordant IBD twin pairs. Among the identified factors were significantly increased proportions of immune cells, including megakaryocytes, neutrophils, natural killer T cells, and lymphatic endothelial cells. The differentially expressed genes were significantly enriched in a gene set associated with cortical and medullary thymocytes. Finally, by combining these expression features with genetic resources, we identified some candidate genes with potential to serve as novel markers of ulcerative colitis, such as CYP2C18. Ulcerative colitis is a subtype of inflammatory bowel disease and a polygenic disorder. Through integrative analysis, we identified some genes, such as CYP2C18, that are involved in the pathogenesis of IBD as well as some candidate therapeutic targets, such as LOXL2.

Bile acids modulate colonic MAdCAM-1 expression in a murine model of combined cholestasis and colitis

Primary sclerosing cholangitis (PSC) is a progressive fibrosing cholestatic liver disease that is strongly associated with inflammatory bowel disease (IBD). PSC-associated IBD (PSC-IBD) displays a unique phenotype characterized by right-side predominant colon inflammation and increased risk of colorectal cancer compared to non-PSC-IBD. The frequent association and unique phenotype of PSC-IBD suggest distinctive underlying disease mechanisms from other chronic liver diseases or IBD alone. Multidrug resistance protein 2 knockout (Mdr2-/-) mice develop spontaneous cholestatic liver injury and fibrosis mirroring human PSC. As a novel model of PSC-IBD, we treated Mdr2-/- mice with dextran sulfate sodium (DSS) to chemically induce colitis (Mdr2-/-/DSS). Mdr2-/- mice demonstrate alterations in fecal bile acid composition and enhanced colitis susceptibility with increased colonic adhesion molecule expression, particularly mucosal addressin-cell adhesion molecule 1 (MAdCAM-1). In vitro, ursodeoxycholic acid (UDCA) co-treatment resulted in a dose dependent attenuation of TNF-α-induced endothelial MAdCAM-1 expression. In the combined Mdr2-/-/DSS model, UDCA supplementation attenuated colitis severity and downregulated intestinal MAdCAM-1 expression. These findings suggest a potential mechanistic role for alterations in bile acid signaling in modulating MAdCAM-1 expression and colitis susceptibility in cholestasis-associated colitis. Together, our findings provide a novel model and new insight into the pathogenesis and potential treatment of PSC-IBD.

Review of primary sclerosing cholangitis with increased IgG4 levels

Primary sclerosing cholangitis (PSC) is a chronic progressive liver disease. Sub-types of PSC have been described, most recently PSC with elevated serum and/or tissue IgG4 subclass. We aim to summarise the clinical phenotype, disease associations, differential diagnosis, response to therapy and pathogenic mechanisms underlying PSC-high IgG4 subtype. We reviewed PubMed, MEDLINE and Embase with the search terms "primary sclerosing cholangitis", "IgG4", and "IgG4-related sclerosing cholangitis (IgG4-SC)". Elevated serum IgG4 are found in up-to one-quarter, and abundant IgG4-plasma cell infiltrates in the liver and bile ducts are found in up-to one-fifth of PSC patients. This group have a distinct clinical phenotype, with some studies reporting a more aggressive course of liver and associated inflammatory bowel disease, compared to PSC-normal IgG4 and the disease mimic IgG4-SC. Distinguishing PSC-high IgG4 from IgG4-SC remains challenging, requiring careful assessment of clinical features, organ involvement and tissue morphology. Calculation of serum IgG4:IgG1 ratios and use of a novel IgG4:IgG RNA ratio have been reported to have excellent specificity to distinguish IgG4-SC and PSC-high IgG4 but require validation in larger cohorts. A role for corticosteroid therapy in PSC-high IgG4 remains unanswered, with concerns of increased toxicity and lack of outcome data. The immunological drivers underlying prominent IgG4 antibodies in PSC are incompletely defined. An association with PSC-high IgG4 and HLA class-II haplotypes (B*07, DRB1*15), T-helper2 and T-regulatory cytokines (IL4, IL10, IL13) and chemokines (CCL1, CCR8) have been described. PSC-high IgG4 have a distinct clinical phenotype and need careful discrimination from IgG4-SC, although response to immunosuppressive treatments and long-term outcome remains unresolved. The presence of IgG4 likely represents chronic activation to persistent antigenic exposure in genetically predisposed individuals.

An update on treatment options for primary sclerosing cholangitis

Primary sclerosing cholangitis is a chronic cholestatic liver disease defined by strictures of the biliary tree which could ultimately lead to liver cirrhosis and cholangiocarcinoma. Although the exact underlying etiology of this disorder is not fully understood, the pathology is believed to be caused by immune mediated mechanisms. Growing body of evidence suggests several treatment modalities mainly focusing on the inflammation aspect of this disorder. However, there is still no consensus regarding the best treatment option for these patients. Thus, the present study aimed to review the current treatment options for patients with primary sclerosing cholangitis.

Effects of Vedolizumab in Patients With Primary Sclerosing Cholangitis and Inflammatory Bowel Diseases

BACKGROUND & AIMS

Gut-homing lymphocytes that express the integrin α4β7 and CCR9 might contribute to development of primary sclerosing cholangitis (PSC). Vedolizumab, which blocks the integrin α4β7, is used to treat patients with inflammatory bowel diseases (IBD), but there are few data on its efficacy in patients with PSC. We investigated the effects of vedolizumab in a large international cohort of patients with PSC and IBD.

METHODS

We collected data from European and North American centers participating in the International PSC Study Group from patients with PSC and IBD who received at least 3 doses of vedolizumab (n = 102; median vedolizumab treatment duration, 412 days). Demographic and clinical data were collected from baseline and during the follow-up period (until liver transplantation, death, or 56 days after the final vedolizumab infusion). We analyzed overall changes in biochemical features of liver and proportions of patients with reductions in serum levels of alkaline phosphatase (ALP) of 20% or more, from baseline through last follow-up evaluation. Other endpoints included response of IBD to treatment (improved, unchanged, or worsened, judged by the treating clinician, as well as endoscopic score) and liver-related outcomes.

RESULTS

In the entire cohort, the median serum level of ALP increased from 1.54-fold the upper limit of normal at baseline to 1.64-fold the upper limit of normal at the last follow-up examination (P = .018); serum levels of transaminases and bilirubin also increased by a small amount between baseline and the last follow-up examination. Serum levels of ALP decreased by 20% or more in 21 patients (20.6%); only the presence of cirrhosis (odds ratio, 4.48; P = .019) was independently associated with this outcome. Of patients with available endoscopic data, 56.8% had a response of IBD to treatment. Liver-related events occurred in 21 patients (20.6%), including bacterial cholangitis, cirrhosis decompensation, or transplantation.

CONCLUSIONS

In an analysis of patients with PSC and IBD in an international study group, we found no evidence for a biochemical response to vedolizumab, although serum level of ALP decreased by 20% or more in a subset of patients. Vedolizumab appears to be well tolerated and the overall response of IBD was the same as expected for patients without PSC.