Several lines of evidence show that serum alkaline phosphatase (AP) is not only a signpost of cholestasis but also a surrogate marker of the severity of primary biliary cirrhosis and primary ...sclerosing cholangitis. In the present opinion article, we review and discuss the putative role of liver AP in health and in cholestatic diseases. In inflammatory cholestatic conditions, loss of activity of liver AP (resulting from its relocation from canaliculi and the acidic milieu) might promote hyper‐adenosine triphosphate‐bilia, lipopolysaccharide overload, and subsequent exacerbation and perpetuation of inflammation. Drugs that can restore the polarity of hepatocytes and canalicular export of bile acids or act as bile alkalinity modifiers are predicted to exert anti‐inflammatory effects and to benefit both primary biliary cirrhosis and primary sclerosing cholangitis. Oral administration of intestinal AP could be a valid therapeutic intervention that deserves further study under experimental conditions as well as in human diseases. Overall, the key role of the liver microenvironment that might shape the different facets of the inflammatory processes in fibrosing cholangiopathies is highlighted. (Hepatology 2015;61:2080–2090)
Summary Cholestasis is an impairment of bile formation/flow at the level of the hepatocyte and/or cholangiocyte. The first, and for the moment, most established medical treatment is the natural bile ...acid (BA) ursodeoxycholic acid (UDCA). This secretagogue improves, e.g. in intrahepatic cholestasis of pregnancy or early stage primary biliary cirrhosis, impaired hepatocellular and cholangiocellular bile formation mainly by complex post-transcriptional mechanisms. The limited efficacy of UDCA in various cholestatic conditions urges for development of novel therapeutic approaches. These include nuclear and membrane receptor agonists and BA derivatives. The nuclear receptors farnesoid X receptor (FXR), retinoid X receptor (RXR), peroxisome proliferator-activated receptor α (PPARα), and pregnane X receptor (PXR) are transcriptional modifiers of bile formation and at present are under investigation as promising targets for therapeutic interventions in cholestatic disorders. The membrane receptors fibroblast growth factor receptor 4 (FGFR4) and apical sodium BA transporter (ASBT) deserve attention as additional therapeutic targets, as does the potential therapeutic agent nor UDCA, a 23-C homologue of UDCA. Here, we provide an overview on established and future promising therapeutic agents and their potential molecular mechanisms and sites of action in cholestatic diseases.
Background & Aims The biochemical response to ursodeoxycholic acid (UDCA) in primary biliary cirrhosis (PBC) correlates with the long-term prognosis and thus could allow the identification of the ...patients needing new therapeutic approaches. Due to variation in both endpoints and studied populations, there is still no full agreement on the definition of the biochemical response. The aim of our study was to determine, in a population of patients with only early-stage disease, the best biochemical criteria of response to UDCA allowing to predict the absence of poor outcome, as defined by liver-related death, liver transplantation, complications of cirrhosis, or histological evidence of cirrhosis development. Methods The efficiency of several combinations of serum bilirubin, alkaline phosphatase (ALP), and aspartate aminotransferase (AST) threshold values to predict outcome was assessed after 1 year of UDCA in 165 patients with early-stage PBC followed up for an average 7 years. The Barcelona, Paris, Rotterdam, and Toronto criteria were also assessed. Results The most accurate discrimination of the patients according to the multiple endpoints was given by the following criteria: ALP and AST ⩽1.5× upper limit of normal, with a normal bilirubin level. Responders and non-responders were equally distributed, while all adverse events were observed in non-responders ( p <0.001). These criteria remained valid when early PBC was defined by both normal bilirubin and albumin concentrations at baseline. Conclusions This study defines the best efficient biochemical response to UDCA that identifies patients with early PBC at very low risk of long-term development of liver failure or cirrhosis.
Summary The liver is selectively enriched in innate immune cells, macrophages (Kupffer cells), natural killer, and natural killer T cells. These cells release an array of mediators with cytotoxic, ...pro- and anti-inflammatory, angiogenic, fibrogenic, and mitogenic activity that function to fight infections, limit tissue injury, and promote wound healing. The diverse activity of macrophages is mediated by distinct subpopulations that develop in response to signals within their microenvironment. Understanding the mechanisms and role of the microenvironment contributing to modulation of macrophage populations is crucial for comprehension of the pathophysiology of liver injury in diverse conditions. Several studies initiated in the 1990s have shown that bile acids modulate innate and adaptive immunity. In the last decade, bile acids turned into hormones and signalling molecules involved in many metabolic and inflammatory processes. Biological properties of bile acids are thought to be mediated mainly through activation of the nuclear receptor FXR, the membrane receptor TGR5, as well as PK, ERK, MAP kinases signalling pathways. FXR and TGR5 agonists are currently under development for clinical purpose. This review analyses the mechanisms involved in the immunomodulatory effects of bile acids on the macrophage and discuss their implications in the pathophysiology of cholestasis, primary biliary cirrhosis and primary sclerosing cholangitis.
Biochemical response to ursodeoxycholic acid (UDCA) in patients with primary biliary cirrhosis (PBC) is variable. It has been recently proposed that an alkaline phosphatase (ALP) decline of more than ...40% in baseline value or a normal level after 1 year of UDCA treatment (Barcelona criteria) could serve as a good marker of long‐term prognosis. Our aim was to define the best efficient set of biochemistries able to identify UDCA‐treated patients at risk of death or liver transplantation (LT). The efficiency of several combinations of serum bilirubin, ALP, and aspartate aminotransferase (AST) threshold values to predict outcome was assessed after 1 year of treatment in 292 patients with PBC. Patients showing ALP <3 upper limit of normal (ULN), AST <2 ULN, and bilirubin ≤1 mg/dL after 1 year of UDCA had a 10‐year transplant‐free survival rate of 90% (95% confidence interval, 81%–95%), compared to 51% (95% confidence interval, 38%–64%) for those who did not (P < 0.001). Patients were less well discriminated by the Barcelona criteria (79% versus 63%). Independent predictive factors of death or LT were baseline serum bilirubin level >1 mg/dL (relative risk RR, 1.7), histologic stage ≥3 (RR, 1.5), interface hepatitis (RR, 1.9), and the absence of biochemical response (ALP >3 ULN or AST >2 ULN, or bilirubin >1 mg/dL) (RR, 2.3). Antinuclear antibodies against gp210 or Sp100 proteins were associated with death or LT in univariate but not in multivariate analysis. Conclusion: This study defines the best efficient biochemical response to UDCA, which, independent of baseline predictive factors, identifies patients with PBC with a good long‐term prognosis. Patients who fail to achieve this response and those with interface hepatitis or advanced histological stage should be targeted for further therapeutic research. (HEPATOLOGY 2008.)
Primary biliary cirrhosis (PBC) is a chronic inflammatory autoimmune disease that mainly targets the cholangiocytes of the interlobular bile ducts in the liver. The condition primarily affects ...middle-aged women. Without treatment, PBC generally progresses to cirrhosis and eventually liver failure over a period of 10–20 years. PBC is a rare disease with prevalence of less than 1/2000. PBC is thought to result from a combination of multiple genetic factors and superimposed environmental triggers. The contribution of the genetic predisposition is evidenced by the familial clustering. Several risk factors, including exposure to infectious agents and chemical xenobiotics, have been suggested. Ursodeoxycholic acid (UDCA) is currently the only FDA-approved medical treatment for PBC. When administered at doses of 13–15 mg/kg/day, a majority of patients with PBC have a normal life expectancy without additional therapeutic measures. One out of three patients does not adequately respond to UDCA therapy and may need additional medical therapy and/or liver transplantation. This review summarises current knowledge on the epidemiology, ethiopathogenesis, clinical, and therapeutic aspects of PBC.
Low phospholipid-associated cholelithiasis (LPAC) is characterized by the association of ABCB4 mutations and low biliary phospholipid concentration with symptomatic and recurring cholelithiasis. This ...syndrome is infrequent and corresponds to a peculiar small subgroup of patients with symptomatic gallstone disease. The patients with the LPAC syndrome present typically with the following main features: age less than 40 years at onset of symptoms, recurrence of biliary symptoms after cholecystectomy, intrahepatic hyperechoic foci or sludge or microlithiasis along the biliary tree. Defect in ABCB4 function causes the production of bile with low phospholipid content, increased lithogenicity and high detergent properties leading to bile duct luminal membrane injuries and resulting in cholestasis with increased serum gamma-glutamyltransferase (GGT) activity. Intrahepatic gallstones may be evidenced by ultrasonography (US), computing tomography (CT) abdominal scan or magnetic resonance cholangiopancreatography, intrahepatic hyperechogenic foci along the biliary tree may be evidenced by US, and hepatic bile composition (phospholipids) may be determined by duodenoscopy. In all cases where the ABCB4 genotyping confirms the diagnosis of LPAC syndrome in young adults, long-term curative or prophylactic therapy with ursodeoxycholic acid (UDCA) should be initiated early to prevent the occurrence or recurrence of the syndrome and its complications. Cholecystectomy is indicated in the case of symptomatic gallstones. Biliary drainage or partial hepatectomy may be indicated in the case of symptomatic intrahepatic bile duct dilatations filled with gallstones. Patients with end-stage liver disease may be candidates for liver transplantation.
Hepatocellular carcinoma (HCC) is an infrequent yet critical event in primary biliary cirrhosis (PBC); however, predictive tools remain ill-defined. Our objective was to identify candidate risk ...factors for HCC development in patients with PBC.
Risk factor analysis was performed in over 15 centres from North America and Europe spanning >40 years observation period using Cox proportional hazards assumptions, logistic regression, and Kaplan-Meier estimates.
Of 4565 patients with PBC 123 developed HCC, yielding an incidence rate (IR) of 3.4 cases/1000 patient-years. HCC was significantly more common in men (p<0.0001), and on univariate analysis factors at PBC diagnosis associated with future HCC development were male sex (unadjusted HR 2.91, p<0.0001), elevated serum aspartate transaminase (HR 1.24, p<0.0001), advanced disease (HR 2.72, p=0.022), thrombocytopenia (HR 1.65, p<0.0001), and hepatic decompensation (HR 9.89, p<0.0001). As such, non-treatment with ursodeoxycholic acid itself was not associated with cancer development; however, 12-month stratification by biochemical non-response (Paris-I criteria) associated significantly with future risk of HCC (HR 4.52, p<0.0001; IR 6.6 vs 1.4, p<0.0001). Non-response predicted future risk in patients with early stage disease (IR 4.7 vs 1.2, p=0.005), advanced disease (HR 2.79, p=0.02; IR 11.2 vs 4.4, p=0.033), and when restricting the analysis to only male patients (HR 4.44, p<0.001; IR 18.2 vs 5.4, p<0.001). On multivariable analysis biochemical non-response remained the most significant factor predictive of future HCC risk (adjusted HR 3.44, p<0.0001).
This uniquely powered, internationally representative cohort robustly demonstrates that 12-month biochemical non-response is associated with increased future risk of developing HCC in PBC. Such risk stratification is relevant to patient care and development of new therapies.
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