Controversies in the management of primary sclerosing cholangitis

The Emerging Role of Macrophages in Chronic Cholangiopathies Featuring Biliary Fibrosis: An Attractive Therapeutic Target for Orphan Diseases

Cholangiopathies are a heterogeneous group of chronic liver diseases caused by different types of injury targeting the biliary epithelium, such as genetic defects and immune-mediated attacks. Notably, most cholangiopathies are orphan, thereby representing one of the major gaps in knowledge of the modern hepatology. A typical hallmark of disease progression in cholangiopathies is portal scarring, and thus development of effective therapeutic approaches would aim to hinder cellular and molecular mechanisms underpinning biliary fibrogenesis. Recent lines of evidence indicate that macrophages, rather than more conventional cell effectors of liver fibrosis such as hepatic stellate cells and portal fibroblasts, are actively involved in the earliest stages of biliary fibrogenesis by exchanging a multitude of cues with cholangiocytes, which promote their recruitment from the circulating compartment owing to a senescent or an immature epithelial phenotype. Two cholangiopathies, namely primary sclerosing cholangitis and congenital hepatic fibrosis, are paradigmatic of this mechanism. This review summarizes current understandings of the cytokine and extracellular vesicles-mediated communications between cholangiocytes and macrophages typically occurring in the two cholangiopathies to unveil potential novel targets for the treatment of biliary fibrosis.

3,5-Diethoxycarbonyl-1,4-Dihydrocollidine Diet: A Rodent Model in Cholestasis Research

Liver cholestasis is characterized by impairment in bile flow. Among cholestatic diseases, primary biliary cholangitis and primary sclerosing cholangitis represent relevant causes of chronic liver disease, associated to significant morbidity and mortality. To better understand and to address therapeutic strategies to cholangiopathies is essential to develop an in vivo model which recapitulates the pathological features of the disease. Chronic feeding of 3,5-diethoxycarbonyl-1,4-dihydrocollidine, named DDC, has been proposed as an in vivo model for cholestatic disease due to the formation of intraductal porphyrin plugs. Chronic feeding of DDC in mice reproduces the main histopathological hallmarks of human cholestatic disease such as (1) remodeling of biliary compartments giving rise to ductular reaction, (2) periductular fibrosis, and (3) inflammatory infiltrate. This chapter describes the materials and methods necessary for the development and characterization of DDC diet-based mouse model.

PRIMARY SCLEROSING CHOLANGITIS IN CHILDREN AND ADOLESCENTS

ABSTRACT BACKGROUND: Primary sclerosing cholangitis is a rare disease, but its prevalence has been underestimated in children and adolescents due to broad variation in clinical presentation as well as diagnostic challenges in this life period. OBJECTIVE: To evaluate children and adolescents with primary sclerosing cholangitis and to describe their clinical, laboratorial, histopathological, and cholangiography conditions. METHODS: This is an observational descriptive research that took place from 2005 to 2016 and included all the patients seen in the Outpatient Unit for Pediatric Hepatology of Hospital das Clinicas of UFMG who had been diagnosed with primary sclerosing cholangitis before the age of 18. Diagnosis was established through clinical, laboratory, radiographic and/or histopathologic criteria. Other chronic liver diseases were excluded, as well as secondary causes of cholangitis. Data analysis used statistic resources in SPSS software. Variables were expressed as averages, standard deviation, absolute frequency, and percentage. RESULTS: Twenty-one patients fulfilled criteria to be included in the research sample. Male patients predominated (3.2:1) and average age at diagnosis was 6.7±3.9 years. Five (23.8%) patients had associated inflammatory bowel disease, four had ulcerative colitis and one indeterminate colitis. Signs and symptoms vary and are usually discrete at presentation. The most frequent symptom was abdominal pain (47.6%) followed less frequently by jaundice (28.6%) and itching (14.3%). The reason for medical investigation was asymptomatic or oligosymptomatic enzyme alterations in 33.3% of patients. All patients presented increased hepatic enzymes: aminotransferases, gamma glutamyl transferase, and alkaline phosphatase. Twenty patients had alterations compatible to primary sclerosing cholangitis in their cholangiography exam; one patient had no alterations at magnetic resonance cholangiography, but presented histopathologic alterations that were compatible to small duct cholangitis. Hepatic fibrosis was present in 60% of 15 patients who were biopsied upon admission; cirrhosis being present in four (26.7%) patients. A total of 28.5% of patients had unfavorable outcomes, including two (9.5%) deaths and four (19%) transplants. CONCLUSION: Primary sclerosing cholangitis is a rare disease in childhood and adolescence and its initial diagnosis may be delayed or overlooked due to asymptomatic or unspecific clinical manifestations. The association with inflammatory bowel disease is common. Prognosis may be unfavorable as the disease progresses and hepatic transplant is the definitive treatment.

Emerging treatments for primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic, cholestatic, idiopathic liver disease that can progress to end-stage liver disease, cirrhosis and cholangiocarcinoma. PSC is an uncommon and highly heterogeneous disease, associated with inflammatory bowel disease and a complex pathophysiology. To date, no medical therapies have proved effective. The only available treatment for end-stage PSC is liver transplant, but recurrence is a significant complication. Areas covered: This review will explore previously tested treatments, discuss current treatment strategies and present viewpoints about future emerging therapies in PSC. We searched PubMed using the noted keywords. We included data from full-text articles published in English. Further relevant articles were identified from the reference lists of review articles. Expert commentary: The development of new therapies in PSC has been challenging. However, with greater awareness of the disease nowadays, new insights into the disease may help in the design of future therapeutic agents in PSC and ultimately in effective therapies.

Macrophage Depletion Attenuates Extracellular Matrix Deposition and Ductular Reaction in a Mouse Model of Chronic Cholangiopathies

Chronic cholangiopathies, such as primary and secondary sclerosing cholangitis, are progressive disease entities, associated with periportal accumulation of inflammatory cells, encompassing monocytes and macrophages, peribiliary extracellular matrix (ECM) deposition and ductular reaction (DR). This study aimed to elucidate the relevance of macrophages in the progression of chronic cholangiopathies through macrophage depletion in a 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) mouse model. One group of mice received a single i.p. injection of Clodronate encapsulated liposomes (CLOLipo) at day 7 of a 14 day DDC treatment, while control animals were co-treated with PBSLipo instead. Mice were sacrificed after 7 or respectively 14 days of treatment for immunohistochemical assessment of macrophage recruitment (F4/80), ECM deposition (Sirius Red, Laminin) and DR (CK19). Macrophage depletion during a 14 day DDC treatment resulted in a significant inhibition of ECM deposition. Porto-lobular migration patterns of laminin-rich ECM and ductular structures were significantly attenuated and a progression of DR was effectively inhibited by macrophage depletion. CLOLipo co-treatment resulted in a confined DR to portal regions without amorphous cell clusters. This study suggests that therapeutic options selectively directed towards macrophages might represent a feasible treatment for chronic cholestatic liver diseases.