Florid biliary duct lesions in an AMA -positive patient in absence of cholestatic liver biochemistry

Caffeic acid borate functionalized linear polyglycidol for targeted siRNA delivery in the treatment of primary biliary cholangitis

Interfering with protein arginine methyltransferase 5 (PRMT5) gene expression with siRNA targeting is a promising strategy for precision primary biliary cholangitis (PBC) therapy, yet achieving effective and specific delivery of therapeutic agents to the liver remains challenging. In this study, we develop a caffeic acid borate derived linear polyglycidol polymer micelle CAPG, which can efficiently deliver siRNA to liver. The degradation of borate and hydrazone bonds in the high-ROS and acidic environment of inflammatory cells triggers micelle disintegration, facilitating siRNA release. Comprehensive in vivo experiments demonstrate that siRNA1@CAPG can significantly reduce the concentration of liver inflammation-related biomarkers and pro-inflammatory factors and notably increase superoxide dismutase (SOD) levels in mice, outperforming free siRNA1 in suppressing PRMT5 expression. Therefore, our study offers valuable reference for the treatment of primary biliary cholangitis.

Primary biliary cholangitis with normal alkaline phosphatase: A neglected clinical entity challenging current guidelines

BACKGROUND & AIM

The diagnosis of primary biliary cholangitis (PBC), an uncommon immune-mediated cholestatic liver disease, is based on positive circulating anti-mitochondrial (AMA) and/or PBC-specific anti-nuclear autoantibodies (ANA), coupled with elevated serum alkaline phopsphatase (ALP) levels. Timely initiation of treatment with ursodeoxycholic acid prevents progression to cirrhosis and liver failure. We aimed at investigating liver histology in patients with normal ALP level and positive AMA and/or PBC-specific ANA.

METHODS

We searched the Swiss PBC Cohort Study database, which includes subjects with positive PBC autoimmune serology and normal ALP levels, for patients who underwent a liver biopsy. Histological slides were centrally reviewed by an expert liver pathologist, and sera were centrally re-tested for AMA and ANA.

RESULTS

30 patients were included; 90% females, median age 53 (range 27-72) years. Twenty-four (80%) had liver histology typical for (n = 2), consistent with (n = 16) or suggestive of (n = 6) PBC, including three of four AMA-negative ANA-positive patients. Among 22 ursodeoxycholic acid treated patients, 14 had elevated GGT levels before treatment; a significant decrease of the median GGT level between pre- (1.46 x ULN) and post- (0.43 x ULN) treatment (p = 0.0018) was observed.

CONCLUSIONS

In our series, a high proportion of AMA positive patients with normal ALP levels have PBC. For the first time we show histological diagnosis of PBC in AMA-negative/PBC-specific ANA-positive subjects and the potential role of GGT as a biomarker in PBC patients with normal baseline ALP levels. Current guidelines for the diagnosis of PBC do not cover the whole extent of PBC presentation, with important clinical implications in terms of timely treatment initiation.

Recurrence of disease following organ transplantation in autoimmune liver disease and systemic lupus erythematosus

Disease recurrence after organ transplantation associated with graft failure is a major clinical challenge in autoimmune diseases. Primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune Hepatitis (AIH) are the three most common (autoimmune liver diseases) ALD for which liver transplantation (LT) is the most effective treatment option for patients with end-stage diseases. Although the 5- and 10-year survival rates of post-LT patients are remarkable (80-84% and 71-79% in PBC, 73-87% and 58-83% in PSC, 76-79% and 67-77% respectively in AIH patients), post-LT disease recurrence is not uncommon. Here, we summarize literature findings on disease recurrence of these ALD with emphasis on the incidence, risk factors and impact on long-term outcome. We noted that the incidence of disease recurrence varies between studies, which ranges from 53% to 10.9% in PBC, 8.2% to 44.7% in PSC and 7% to 42% in AIH. The variations are likely due to differences in study design, such as sample size, duration of studies and follow up time. This is further compounded by the lack of precise clinical diagnosis criteria and biomarkers of disease recurrence in these ALD, variation in post-LT treatment protocols to prevent disease recurrence and a multitude of risk factors associated with these ALD. While recurrence of PBC and AIH does not significantly impact long term outcome including overall survival, recurrent PSC patients often require another LT. Renal transplantation, like LT, is the treatment of choice in patients with end-stage lupus nephritis. While calcineurin inhibitor (CNI) and immunosuppressive drugs have improved the survival rate, post-transplant recurrence of lupus nephritis from surveillance-biopsy proven lupus nephritis range from 30% to 44%. On the other hand, recurrence of post-transplant lupus nephritis from registry survey analysis were only 1.1% to 2.4%. In general, risk factors associated with an increased frequency of post-transplant recurrence of autoimmune diseases are not clearly defined. Large scale multi-center studies are needed to further define guidelines for the diagnosis and clinical management to minimize disease recurrence and improve outcomes of post-transplant patients.

The challenges of primary biliary cholangitis: What is new and what needs to be done

Primary Biliary Cholangitis (PBC) is an uncommon, chronic, cholangiopathy of autoimmune origin and unknown etiology characterized by positive anti-mitochondrial autoantibodies (AMA), female preponderance and progression to cirrhosis if left untreated. The diagnosis is based on AMA- or PBC-specific anti-nuclear antibody (ANA)-positivity in the presence of a cholestatic biochemical profile, histologic confirmation being mandatory only in seronegative cases. First-line treatment is ursodeoxycholic acid (UDCA), which is effective in preventing disease progression in about two thirds of the patients. The only approved second-line treatment is obeticholic acid. This article summarizes the most relevant conclusions of a meeting held in Lugano, Switzerland, from September 23rd-25th 2018, gathering basic and clinical scientists with various background from around the world to discuss the latest advances in PBC research. The meeting was dedicated to Ian Mackay, pioneer in the field of autoimmune liver diseases. The role of liver histology needs to be reconsidered: liver pathology consistent with PBC in AMA-positive individuals without biochemical cholestasis is increasingly reported, raising the question as to whether biochemical cholestasis is a reliable disease marker for both clinical practice and trials. The urgent need for new biomarkers, including more accurate markers of cholestasis, was also widely discussed during the meeting. Moreover, new insights in interactions of bile acids with biliary epithelia in PBC provide solid evidence of a role for impaired epithelial protection against potentially toxic hydrophobic bile acids, raising the fundamental question as to whether this bile acid-induced epithelial damage is the cause or the consequence of the autoimmune attack to the biliary epithelium. Strategies are needed to identify difficult-to-treat patients at an early disease stage, when new therapeutic approaches targeting immunologic pathways, in addition to bile acid-based therapies, may be effective. In conclusion, using interdisciplinary approaches, groundbreaking advances can be expected before long in respect to our understanding of the etiopathogenesis of PBC, with the ultimate aim of improving its treatment.