Protective potential of the gallbladder in primary sclerosing cholangitis

[Primary sclerosing cholangitis-Diagnosis and treatment 2024]

The etiology of primary sclerosing cholangitis (PSC) remains unclear, which explains in part the lack of a causal treatment. The differential diagnostic distinction from the even rarer immunoglobulin 4 (IgG4)-associated cholangitis (IAC) is becoming increasingly more successful. Advances in the understanding of different clinical courses, improvements in noninvasive diagnostics through modern magnetic resonance imaging (MRI) and the introduction of liver elastography have led to the development of improved prognostic models. The evidence for recommendations on medicinal (e.g., ursodeoxycholic acid) or endoscopic treatment (e.g., balloon dilatation and/or stent insertion) for PSC is still low. In contrast, the long-term results of liver transplantation in PSC patients are constantly improving. Due to the lack of highly sensitive and specific screening methods the early recognition of cholangiocellular carcinoma (CCC) as the most important complication is rarely successful. The continuous improvement of endoscopic retrograde cholangiopancreatography (ERCP) and direct cholangioscopy in combination with molecular biological and fluorescence in situ hybridization (FISH) analyses of bile duct tissue samples are promising for refined diagnostics. Due to the significantly increased risk of colorectal cancer, an annual colonoscopy is recommended in the presence of inflammatory bowel disease. Improvement of the early diagnostics of PSC and successful testing of new treatment strategies raise hope for a continuous improvement in the medical support of these complex patients.

Spontaneous perforation of the common bile duct: an uncommon complication of primary sclerosing cholangitis

OBJECTIVES

To describe the MR features and prognosis of patients with an uncommon complication of primary sclerosing cholangitis (PSC) characterized by a spontaneous perforation of the common bile duct (CBD) resulting in a peri-biliary collection and a pseudo-cystic appearance of the CBD.

METHODS

A single-center cohort of 263 patients with PSC who had at least two MRIs between 2003 and 2022 and a minimum follow-up of 1 year was retrospectively analyzed. MRI data (characteristics of CBD perforation and MR features of PSC) and clinical data were assessed. Analysis of survival without liver transplantation according to type of PSC (classical or CBD spontaneous perforation) was performed according to the Kaplan-Meier method and the curves were compared using the Log-Rank test.

RESULTS

A total of nine (3.4%) PSC patients (5 males) had perforation of the CBD with a median age at diagnosis of 18 years compared to 33 years for the control group (p = 0.019). The peri-biliary collections were variable in appearance (fusiform or pedunculated), with a diameter ranging from 5 to 54 mm. All nine patients showed intra- and extra-hepatic bile duct involvement, dysmorphia, and high ANALI scores. The clinical course was characterized by numerous complications in most patients, and five patients (56%) underwent liver transplantation at a median time of 5 years from diagnosis, compared to 40 patients (16%) in the control group (p = 0.02).

CONCLUSION

The spontaneous perforation of the common bile duct is an uncommon complication of primary sclerosing cholangitis that affects young patients and is associated with a poor prognosis.

CLINICAL RELEVANCE STATEMENT

This uncommon complication of primary sclerosing cholangitis with perforation of the common bile duct resulting in a peri-biliary collection and a pseudo-cystic appearance of the common bile duct is characterized by a poor prognosis in younger patients.

KEY POINTS

• Among 263 patients with primary sclerosing cholangitis (PSC), nine patients (3.6%) had an uncommon complication characterized on MRI by perforation of the common bile duct (CBD). • This perforation of the CBD was responsible in all nine cases for the formation of a peri-biliary collection, giving a pseudo-cystic appearance to the CBD. • The spontaneous perforation of the common bile duct is an uncommon complication of primary sclerosing cholangitis that affects young patients with a poor prognosis.

Targeting bile salt homeostasis in biliary diseases

PURPOSE OF REVIEW

Advances in the understanding of bile salt synthesis, transport and signalling show the potential of modulating bile salt homeostasis as a therapeutic strategy in cholestatic liver diseases. Here, recent developments in (pre)clinical research in this field is summarized and discussed.

RECENT FINDINGS

Inhibition of the apical sodium-dependent bile salt transporter (ASBT) and Na + -taurocholate cotransporting polypeptide (NTCP) seems effective against cholestatic liver diseases, as well as Farnesoid X receptor (FXR) agonism or a combination of both. While approved for the treatment of primary biliary cholangitis (PBC) and intrahepatic cholestasis of pregnancy (ICP), ursodeoxycholic acid (UDCA) has retrospectively shown carefully promising results in primary sclerosing cholangitis (PSC). The side chain shortened derivate norUDCA is of further therapeutic interest since its mechanisms of action are independent of the bile salt transport machinery. In the pathogenesis of sclerosing cholangiopathies, a skewed T-cell response with alterations in gut microbiota and bile salt pool compositions are observed. In PSC pathogenesis, the bile salt receptor Takeda G-protein-coupled receptor 5 (TGR5) in cholangiocytes is implicated, whilst in immunoglobulin G4-related cholangitis the autoantigens annexin A11 and laminin 511-E8 are involved in protecting cholangiocytes.

SUMMARY

Modulating bile salt homeostasis has proven a promising treatment strategy in models of cholestasis and are continuously being further developed. Confirmatory clinical studies are needed in order to assess the proposed treatment strategies in patients allowing for a broader therapeutic arsenal in the future.

Primary Sclerosing Cholangitis: Diagnostic Criteria

Primary sclerosing cholangitis is a chronic cholestatic liver disease characterized by inflammation and fibrosis of intra- and/or extrahepatic bile ducts leading to the formation of multifocal strictures alternated to bile duct dilatations. The diagnosis of the most common subtype of the disease, the large duct PSC, is based on the presence of elevation of cholestatic indices, the association of typical cholangiographic findings assessed by magnetic resonance cholangiography and the exclusion of causes of secondary sclerosing cholangitis. Liver biopsy is not routinely applied for the diagnosis of large duct PSC but is mandatory in the case of suspicion of small duct PSC or overlap with autoimmune hepatitis.

Developing a Prognostic Model for Primary Biliary Cholangitis Based on a Random Survival Forest Model

Background: Primary biliary cholangitis (PBC) is a rare autoimmune liver disease with few effective treatments and a poor prognosis, and its incidence is on the rise. There is an urgent need for more targeted treatment strategies to accurately identify high-risk patients. The use of stochastic survival forest models in machine learning is an innovative approach to constructing a prognostic model for PBC that can improve the prognosis by identifying high-risk patients for targeted treatment. Method: Based on the inclusion and exclusion criteria, the clinical data and follow-up data of patients diagnosed with PBC-associated cirrhosis between January 2011 and December 2021 at Taizhou Hospital of Zhejiang Province were retrospectively collected and analyzed. Data analyses and random survival forest model construction were based on the R language. Result: Through a Cox univariate regression analysis of 90 included samples and 46 variables, 17 variables with p-values <0.1 were selected for initial model construction. The out-of-bag (OOB) performance error was 0.2094, and K-fold cross-validation yielded an internal validation C-index of 0.8182. Through model selection, cholinesterase, bile acid, the white blood cell count, total bilirubin, and albumin were chosen for the final predictive model, with a final OOB performance error of 0.2002 and C-index of 0.7805. Using the final model, patients were stratified into high- and low-risk groups, which showed significant differences with a P value <0.0001. The area under the curve was used to evaluate the predictive ability for patients in the first, third, and fifth years, with respective results of 0.9595, 0.8898, and 0.9088. Conclusion: The present study constructed a prognostic model for PBC-associated cirrhosis patients using a random survival forest model, which accurately stratified patients into low- and high-risk groups. Treatment strategies can thus be more targeted, leading to improved outcomes for high-risk patients.