Sex differences in clinical presentation and prognosis in patients with primary biliary cholangitis

The treatment of primary biliary cholangitis: from shadow to light

Primary biliary cholangitis (PBC) is a chronic autoimmune cholestatic disease characterized by the destruction of the small intrahepatic bile ducts, which can progress to liver cirrhosis. The gold standard in the treatment of PBC is ursodeoxycholic acid (UDCA), which is indicated in all patients with PBC because it improves not only biochemical parameters but also patients' survival. An important milestone in the identification of patients at risk is the assessment of biochemical response to UDCA. Patients who respond to treatment have a lower incidence of hepatic events and better prognosis than patients who do not. Several scoring systems can be used to assess the response and identify non-responders who will benefit from second-line treatment. Obeticholic acid (OCA) is currently the only approved second-line treatment for PBC, which is effective for non-responders to UDCA therapy or patients, who have not tolerated UDCA therapy. However, OCA is contraindicated in advanced liver cirrhosis and portal hypertension. Moreover, pruritus may be a limiting factor for the administration of OCA. Fibrates have shown promising data supporting their use in non-responders to UDCA because they improve the biochemical parameters and elastographic findings and have possible antipruritic effects. Therefore, the idea of a triple treatment seems interesting. Clinical research is focusing on several other groups of drugs: peroxisome proliferator-activated receptor (PPAR) δ- and α/δ agonists, non-steroidal farnesoid X receptor agonists, fibroblast growth factor 19 modulators, and inhibitors of nicotinamide adenine dinucleotide phosphate oxidase 1 and 4.

Sex-Dependent Differences in Cholestasis: Why Estrogen Signaling May Be a Key Pathophysiological Driver

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are cholestatic liver diseases that have significant clinical impact with debilitating symptoms and mortality. While PBC is predominantly seen in perimenopausal and postmenopausal women, men who are diagnosed with PBC have worse clinical outcomes and all-cause mortality. In contrast, 60% to 70% of patients with PSC are men; the data indicate that female sex may be an independent factor against PSC-related complications. These findings suggest a sex-dependent biological basis for these differences. Estrogen has been implicated in the pathogenesis of intrahepatic cholestasis of pregnancy and may induce cholestasis through a variety of interactions. However, it is unclear why some sexual dimorphic features may provide a protective effect despite known estrogen models that induce cholestasis. This article provides a brief introductory background and discusses the sexual dimorphism in clinical presentation in PSC and PBC. It also explores the role of estrogen signaling in pathogenesis and how it relates to intrahepatic cholestasis of pregnancy. Studies have already targeted certain molecules involved in estrogen signaling, and this review discusses these studies that identify estrogen-related receptor, estrogen receptor-α, estrogen receptor-β, farnesoid X receptor, and mast cells as possible targets, in addition to long noncoding RNA H19-induced cholestasis and sexual dimorphism. It also explores these interactions and their role in the pathogenesis of PBC and PSC.

Risk Stratification in Primary Biliary Cholangitis

Primary Biliary Cholangitis (PBC) is a chronic cholestatic liver disease with a heterogeneous presentation, symptomatology, disease progression, and response to therapy. The current risk stratification assessment, aimed at identifying patients with a higher risk of disease progression, encompasses an in-depth analysis of demographic data, clinical and laboratory findings, antibody profiles, and the evaluation of liver fibrosis using both invasive and noninvasive techniques. Treatment response scores after one year of therapy remain to date a major factor influencing the prognosis of PBC patients. While the initial therapeutic approach with ursodeoxycholic acid (UDCA) is universally applied, new second-line treatment options have recently emerged, with many others under investigation. Consequently, the prevailing one-size-fits-all approach is poised to be supplanted by tailored strategies, ensuring high-risk patients receive the most appropriate treatment regimen from diagnosis. This will require the development of a risk prediction model to assess, at the time of diagnosis, the course, outcome, and response to first and additional treatments of PBC patients. This manuscript provides a comprehensive overview of the current and emerging tools used for risk stratification in PBC and speculates on how these developments might shape the disease landscape in the near future.

The impact of recipient and donor gender-match and mismatch on the post-liver transplant outcomes of patients with primary biliary cholangitis

BACKGROUND & AIMS

In this study, we evaluate the effects of donor gender on post-liver transplant (LT) prognosis. We specifically consider patients with primary biliary cholangitis (PBC).

METHODS

The 2005 to 2019 UNOS transplant registry was used to select patients with PBC. The study cohort was stratified by donor gender. All-cause mortality and graft failure hazards were compared using iterative Cox regression analysis. Subanalyses were performed to evaluate gender mismatch on post-LT prognosis.

RESULTS

There were 1885 patients with PBC. Of these cases, 965 entries had male donors and 920 had female donors. Median follow-up was 4.82 (25-75% IQR 1.83-8.93) years. Having a male donor was associated with higher all-cause mortality (aHR 1.28 95%CI 1.03-1.58) and graft failure (aHR 1.70 95%CI 1.02-2.82). Corresponding incidence rates were also relatively increased. In the sub-analysis of female recipients (n = 1581), those with gender-mismatch (male donors, n = 769) were associated with higher all-cause mortality (aHR 1.41 95%CI 1.11-1.78) but not graft failure. In the male recipient subanalysis (n = 304), no associations were found between gender-mismatch (female donors, n = 108) and all-cause mortality or graft failure.

CONCLUSION

This study shows that recipients who have male donors experienced higher rates of all-cause mortality following LT. This finding was consistent in the female recipient-male donor mismatch cohort.

Primary Biliary Cholangitis: Promising Emerging Innovative Therapies and Their Impact on GLOBE Scores

Primary biliary cholangitis (PBC), previously referred to as primary biliary cirrhosis, is an autoimmune disorder leading to the destruction of intra-hepatic bile ducts. If untreated, progressive bile duct damage and cholestasis can lead to ductopenia and result in cirrhosis. Ursodiol, the first drug approved for PBC, has changed the natural history of this disease and improved patient outcomes. Subsequently, several new prediction models incorporating a response to ursodiol were developed. These include the GLOBE score, which was shown to predict long-term outcomes in patients with PBC. In 2016, obeticholic acid (OCA) became the second drug to be approved by the FDA, predominantly based on improvement in alkaline phosphatase (ALP) levels. This trial has subsequently influenced the design of clinical trials. Several drugs are currently being evaluated as therapeutic options for PBC, with improvement in ALP being a main endpoint. In this review, we will discuss the impact of new therapies on GLOBE scores in patients with PBC.

Gender and Autoimmune Liver Diseases: Relevant Aspects in Clinical Practice

Autoimmune liver diseases (AILDs) include autoimmune hepatitis, primary biliary cholangitis and primary sclerosing cholangitis. The etiologies of AILD are not well understood but appear to involve a combination of genetic and environmental factors. AILDs commonly affect young individuals and are characterized by a highly variable clinical course. These diseases significantly influence quality of life and can progress toward liver decompensation or the onset of hepatocellular or cholangiocarcinoma; a significant number of patients eventually progress to end-stage liver disease, requiring liver transplantation. In this review, we focus on the sex characteristics and peculiarities of AILD patients and highlight the relevance of a sex-specific analysis in future studies. Understanding the sex differences underlying AILD immune dysregulation may be critical for developing more effective treatments.

Current Trends and Characteristics of Hepatocellular Carcinoma in Patients with Autoimmune Liver Diseases

Hepatocellular carcinoma (HCC), the commonest among liver cancers, is one of the leading causes of mortality among malignancies worldwide. Several reports demonstrate autoimmune liver diseases (AILDs), including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) to confer increased risk of hepatobiliary malignancies, albeit at lower frequencies compared to other liver diseases. Several parameters have been recognized as risk factors for HCC development in AIH and PBC, including demographics such as older age and male sex, clinical features, the most decisive being cirrhosis and other co-existing factors, such as alcohol consumption. Moreover, biochemical activity and treatment response have been increasingly recognized as prognostic factors for HCC development in AIH and PBC. As available treatment modalities are effective only when HCC diagnosis is established early, surveillance has been proven essential for HCC prognosis. Considering that the risk for HCC is not uniform between and within disease groups, refinement of screening strategies according to prevailing demographic, clinical, and molecular risk factors is mandated in AILDs patients, as personalized HCC risk prediction will offer significant advantage in patients at high and/or medium risk. Furthermore, future investigations should draw attention to whether modification of immunosuppression could benefit AIH patients after HCC diagnosis.

The Effects of Androgens on T Cells: Clues to Female Predominance in Autoimmune Liver Diseases?

The immune system responds differently in women and in men. Generally speaking, adult females show stronger innate and adaptive immune responses than males. This results in lower risk of developing most of the infectious diseases and a better ability to clear viral infection in women (1–5). On the other hand, women are at increased risk of developing autoimmune diseases (AID) such as rheumatoid arthritis, multiple sclerosis (MS), systemic lupus erythematosus (SLE), Sjögren's syndrome, and the autoimmune liver diseases autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) (6). Factors contributing to the female sex bias in autoimmune diseases include environmental exposure, e.g., microbiome, behavior, and genetics including X chromosomal inactivation of genes. Several lines of evidence and clinical observations clearly indicate that sex hormones contribute significantly to disease pathogenesis, and the role of estrogen in autoimmune diseases has been extensively studied. In many of these diseases, including the autoimmune liver diseases, T cells are thought to play an important pathogenetic role. We will use this mini-review to focus on the effects of androgens on T cells and how the two major androgens, testosterone and dihydrotestosterone, potentially contribute to the pathogenesis of autoimmune liver diseases (AILD).