The Epidemiology of Primary Biliary Cholangitis in European Countries: A Systematic Review and Meta-Analysis

Epidemiology of autoimmune liver disease in Korea: evidence from a nationwide real-world database

BACKGROUND

Autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) are all immune-mediated chronic inflammatory liver diseases. Autoimmune liver diseases are rare, making identification and treatment difficult. To improve clinical outcomes and enhance patient quality of life, we performed an epidemiological study of autoimmune liver diseases based on real-world comprehensive data.

RESULTS

We used National Health Insurance Service claims data in Korea from 2005 to 2019. Patients were identified using the International Classification of Disease 10th Revision code, and rare intractable disease codes assigned according to the strict diagnostic criteria. In the AIH cohort, 8,572 (83.9%) were females and the mean age at diagnosis was 56.3 ± 14.3 years. PBC also showed female dominance (83.3%) and the mean age was 57.8 ± 12.6 years. Patients with PSC showed no sex predominance and had a mean age of 57.8 ± 21.5 years. During the study period, there were 10,212, 6,784, and 888 AIH, PBC, and PSC patients, respectively. The prevalence of AIH, PBC, and PSC in 2019 were 18.4, 11.8, and 1.5 per 100,000 population, while the corresponding incidences were 2.3, 1.4, and 0.3 per 100,000 population, respectively. Analysis of sex-age-standardized data showed that the annual prevalence of these diseases is increasing. The 10-year survival rates were 89.8%, 74.9%, and 73.4% for AIH, PBC, and PSC, respectively.

CONCLUSIONS

The number of patients with autoimmune liver disease in South Korea is increasing over time. Further research on autoimmune liver disease is needed to fulfill unmet clinical needs.

Primary biliary cirrhosis and psoriasis: a two-sample Mendelian randomization study

Background

Primary biliary cirrhosis (PBC) and psoriasis are frequently observed to co-occur in clinical settings. However, the causal associations and underlying mechanisms between PBC and psoriasis remain poorly defined.

Methods

In this study, we conducted bidirectional MR analysis to explore the causal relationship between PBC and psoriasis using four MR methods: inverse-variance weighted, MR-Egger regression, weighted median, and weighted mode. Sensitivity analyses were carried out, employing different models and testing methods for comparison to assess the influence of heterogeneity and pleiotropy on our findings and to confirm the robustness of these results.

Results

A causal relationship between the risk of PBC and psoriasis was identified, as confirmed by IVW analysis (OR: 1.081, 95%CI: 1.028~1.137, P<0.05). The other three MR methods also produced similar results. However, psoriasis did not have a causal effect on PBC risk (OR: 1.022, 95%CI: 0.935~1.118, P>0.05). The intercept of MR-Egger regression was 0.0013 (P>0.05), indicating that genetic pleiotropy did not influence the results. Additionally, the leave-one-out analysis demonstrated the robustness of our MR findings.

Conclusion

This study reveals a causal relationship between PBC and psoriasis, with PBC increasing the risk of psoriasis, but not the reverse. This potential causal relationship offers a new perspective on the etiology of PBC.

Autoimmune liver disease and multiple sclerosis: state of the art and future perspectives

Clinical observations suggest that the prevalence of autoimmune diseases is changing over time. Both autoimmune liver diseases and multiple sclerosis have shown a significant increase in the last decades. Although the coexistence of autoimmune diseases within individuals and families is a common phenomenon, the extent to which liver disease and multiple sclerosis co-occur is not clear. Case reports and few studies have reported the possible coexistence of multiple sclerosis with thyroid diseases, inflammatory bowel disease, psoriasis, and rheumatoid arthritis. It is unknown whether there is a definite association between multiple sclerosis and autoimmune liver diseases. We reviewed the literature to summarize the available studies on the association between different autoimmune liver diseases (autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis) and treated or untreated multiple sclerosis.

Sequence of events leading to primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease that is observed more frequently in middle-aged women. This disorder is considered an autoimmune disease, since liver injury is sustained by the presence of self-directed antimitochondrial antibodies targeting the bile duct cells. The prognosis may vary depending on an early diagnosis and response to therapy. However, nearly a third of patients can progress to liver cirrhosis, thus requiring a liver transplant. Traditional immunosuppressive therapies, commonly employed for other autoimmune diseases, have limited effects on PBC. In fact, dramatic functional changes that occur in the biliary epithelium in the course of inflammation play a major role in perpetuating the injury. In this minireview, after a background on the disease and possible predisposing factors, the sequential cooperation of cellular/molecular events leading to end-stage PBC is discussed in detail. The rise and maintenance of the autoimmune process, as well as the response of the biliary epithelia during inflammatory injury, are key factors in the progression of the disease. The so-called "ductular reaction (DR)", intended as a reactive expansion of cells with biliary phenotype, is a process frequently observed in PBC and partially understood. However, recent findings suggest a strict relationship between this pathological picture and the progression to liver fibrosis, cell senescence, and loss of biliary ducts. All these issues (onset of chronic inflammation, changes in secretive and proliferative biliary functions, DR, and its relationship with other pathological events) are discussed in this manuscript in an attempt to provide a snapshot, for clinicians and researchers, of the most relevant and sequential contributors to the progression of this human cholestatic disease. We believe that interpreting this disorder as a multistep process may help identify possible therapeutic targets to prevent evolution to severe disease.

Characteristic geoepidemiology of primary biliary cholangitis in Taiwan: A nationwide population-based study

AIM

Data on the geoepidemiology and outcomes of primary biliary cholangitis (PBC) in Asia are limited; thus, we aimed to collect and assess this information for Taiwan.

METHODS

A nationwide population-based cohort study was undertaken using data from the Taiwan National Health Insurance Research Database. Primary biliary cholangitis was defined by the International Classification of Diseases, Ninth Revision, Clinical Modification code 571.6 based on alkaline phosphatase and antimitochondrial antibody measurements and ursodeoxycholic acid treatment.

RESULTS

During 2002-2015, 2737 patients (2137 female patients; mean age, 57.78 years) had PBC. The average annual age- and sex-adjusted prevalence and incidence rates of PBC were 8.092/105 and 1.148/105 , respectively. Prevalent cases peaked in patients aged 50-59 years; the female-to-male ratio was 4.21. Annual prevalence rates increased with time (average percentage change, 12.03%; p < 0.0001). The annual incidence rates decreased with time (-7.39%; p = 0.000011) in female patients (-8.94%; p = 0.000003) but remained steady in male patients. Female-to-male and northern-to-southern relative risks of PBC incidence rates ranged from 2.2675 to 4.3318 and from 1.5707 to 3.1725, respectively. The 14-year hepatocellular carcinoma (HCC) cumulative incidence was 9.11%, and the mortality rate was 32.44%; the cumulative incidences of dyslipidemia, thyroid disease, and extrahepatic cancers were 65.13%, 24.40%, and 12.79%, respectively. Higher cumulative incidences of HCC (p = 0.0064) and mortality (p < 0.0001) were noted in male than female PBC patients; southern Taiwan PBC patients had higher cumulative incidences of mortality (p < 0.0001) than their northern counterparts.

CONCLUSION

In Taiwan, decreasing trends in incidence rates and the female-to-male ratio of PBC patients and specific sex and geographic impacts on the incidence rates and outcomes of PBC demand further investigation.

Emerging Therapeutic Strategies in The Fight Against Primary Biliary Cholangitis

The liver has a vital role in many metabolic and regulatory processes in the body. Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is a chronic cholestatic autoimmune disease of the intrahepatic bile ducts associated with loss of tolerance to mitochondrial antigens. At this time there is no definitive cure for PBC; however, ursodeoxycholic acid (UDCA) has been shown to reduce injury when administered as the first line of treatment. Additional therapeutics can be given concurrently or as an alternative to UDCA to manage the symptoms and further curb disease progression. Currently, a liver transplant is the only potentially curative option when the patient has developed end-stage liver disease or intractable pruritus. This review aims to delineate the pathogenesis of primary biliary cholangitis and shed light on current therapeutic strategies in the treatment of PBC.

Current Therapies for Cholestatic Diseases

Cholestasis is a condition characterized by decrease in bile flow due to progressive pathological states that lead to chronic cholestatic liver diseases which affect the biliary tree at the intrahepatic level and extrahepatic level. They induce complications such as cirrhosis, liver failure, malignancies, bone disease and nutritional deficiencies that merit close follow-up and specific interventions. Furthermore, as those conditions progress to liver cirrhosis, there will be an increase in mortality but also an important impact in quality of life and economic burden due to comorbidities related with liver failure. Therefore, it is important that clinicians understand the treatment options for cholestatic liver diseases. With a general view of therapeutic options and their molecular targets, this review addresses the pathophysiology of cholangiopathies. The objective is to provide clinicians with an overview of the safety and efficacy of the treatment of cholangiopathies based on the current evidence.

Changing epidemiology of cirrhosis from 2010 to 2019: results from the Global Burden Disease study 2019

BACKGROUND

Liver cirrhosis is a significant yet largely preventable and underappreciated cause of global health loss. This study aimed to profile the global and regional burdens of liver cirrhosis between 2010 and 2019 and the contributions of various aetiologies.

METHOD

Data on the incidence, mortality, and disability-adjusted life years (DALYs) of cirrhosis were obtained from the Global Burden of Disease 2019 study. The burden of cirrhosis was estimated by age, sex, region, aetiology, and socio-demographic index (SDI). The temporal trend was quantified using the annual percentage changes (APC.).

RESULTS

Globally, there were 2.05 million new cases and 1.47 million deaths due to cirrhosis in 2019. From 2010 to 2019, the age-standardized incidence rate (ASIR) for cirrhosis increased slightly from 25.19 to 25.35 worldwide, while the age-standardized death rate (ASDR) and age-standardized DALYs (ASDALYs) decreased from 20.37 to 18.00 and 639.86 to 560.43, respectively. Cirrhosis incidence, mortality and DALYs were consistently higher in males than females. Stratification according to the socio-demographic index (SDI) revealed that low SDI countries had the highest ASDR and ASDALYs in 2019, while middle SDI countries had the highest ASIR. Regarding the aetiology of cirrhosis, hepatitis C accounted for the largest proportion of cirrhosis-related incidence (26.9%), death (26.8%) and DALYs (26.3%); however, non-alcoholic fatty liver disease (NAFLD) exhibited a rapidly growing cause of incident cirrhosis (+26.7%), cirrhosis-related death (+25.1%), and DALYs (+21.0%) worldwide during this period. The ASIR for NAFLD also significantly increased with APC 1.080 over the study period.

CONCLUSIONS

Albeit the global burden of cirrhosis incidence increased from 2010 to 2019, cirrhosis-associated deaths and DALYs declined significantly. Notably, NAFLD exhibited the most significant increase as a contributor to cirrhosis worldwide.

Contemporary Epidemiology of Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a cholestatic liver disease with potential evolution to liver cirrhosis when left untreated. Despite being rare, PBC has a substantial impact on the quality of life and survival of affected patients. Women are the most diagnosed worldwide; however, male subjects seem to have more aggressive disease and worse prognosis. Changing epidemiologic trends are emerging in PBC, with increasing global prevalence and slight smoothing of sex differences. In this review we present available data on incidence rates and prevalence of PBC worldwide, highlighting geographic differences and factors impacting clinical outcomes.

Diagnostic and Clinical Value of Specific Autoantibodies against Kelch-like 12 Peptide and Nuclear Envelope Proteins in Patients with Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by the presence of antimitochondrial and antinuclear antibodies in patients’ serum. Here, we analyzed the reactivity of autoantibodies against a novel autoantigen, kelch-like 12 (KLHL12) protein, in a cohort of 138 PBC and 90 non-PBC patients. Additionally, we compared the reactivity of KLHL12 with antinuclear envelope antibodies: anti-gp210, anti-p62, and anti-LBR. Commercially available kits and an ‘in-house’ ELISA were used in the studies. Antinuclear envelope antibodies were detected in 65% of PBC patients and the presence of these antibodies was observed more frequently in patients diagnosed with later stages (III/IV) of PBC, according to Ludwig’s classification (p < 0.05) and were found to correlate with a higher concentration of bilirubin. Overall, anti-KLHL12 antibodies were found more frequently in PBC patients than in non-PBC controls (p < 0.001). Anti-KLHL12 antibodies were detected in 36% of the tested PBC cohort, including PBC patients negative for antimitochondrial antibodies. Presence of anti-KLHL12 was also associated with a higher concentration of bilirubin and correlated with fibrosis (p < 0.05). Anti-KLHL12 antibodies were detected in 30% of PBC individuals positive for antinuclear envelope antibodies, while anti-KLHL12 and antinuclear envelope antibodies were found in 17% of all PBC cases. Concluding, our data confirm that antibodies against the KLHL12 protein are highly specific for PBC and when used in combination with other markers, may significantly increase the diagnosis of PBC.

May Previous Hepatitis B Virus Infection Be Involved in Etiology and Pathogenesis of Autoimmune Liver Diseases?

INTRODUCTION

Viral infections, especially with hepatotropic viruses, may trigger autoimmune liver diseases (AILDs) and deteriorate their course. However, association of previous hepatitis B virus (HBV) infection (presence of anti-HBc with or without anti-HBs or HBV DNA in serum) with AILDs is poorly studied so far. The aim of the study was to assess the prevalence of previous hepatitis B virus infection markers and its clinical significance in patients with autoimmune liver diseases.

METHODS

The study was based on the data obtained from 234 consecutive HBsAg-negative patients with AILDs [81 with autoimmune hepatitis (AIH), 122 with primary biliary cholangitis (PBC) and 31 with primary sclerosing cholangitis (PSC)] and 131 subjects of the control group without liver diseases. Blood samples of the enrolled patients were tested for anti-HBc and HBV DNA. Samples of liver tissue were examined by standard morphologic protocol and, in anti-HBc positive subjects, for HBV DNA. We assessed estimated risks of AILDs according to anti-HBc positivity and association of anti-HBc positivity with stage of liver fibrosis.

RESULTS

Anti-HBc was detected in 14.5% participants in the control group vs 26.1% (p = 0.016) in patients with AILDs (including 27.1% subjects with PBC (p = 0.021 vs control group), in 29% of PSC and 23.5% in AIH. HBV DNA was detected in three patients with PBC and in one with AIH. Positive anti-HBc test result was associated with higher risk of AILDs-odds ratio (OR) = 2.078 [95% confidence interval (CI) 1.179-3.665], especially in PBC: OR (95% CI) 2.186 (1.165-4.101). Odds of advanced stage of liver fibrosis (F3-F4 by METAVIR) in anti-HBc-positive subjects with PBC were also higher compared to those who had no previous HBV infection: OR (95% CI) 2.614 (1.153-5.926).

CONCLUSIONS

Significant proportions of patients with AILDs are anti-HBc positive, and some of them have OBI. Among patients with AILDs, anti-HBc-positivity is most widespread in the PBC group and in subjects with advanced stage of liver fibrosis. Our data may support the idea of an important role of previous HBV infection in the etiology and pathogenesis of AILDs (namely PBC).

Von Willebrand factor exerts hepatoprotective effects in acute but not chronic cholestatic liver injury in mice

Acute and chronic liver disease are associated with substantial alterations in the hemostatic system, including elevated levels of the platelet-adhesive protein von Willebrand factor (VWF). Carbon tetrachloride-induced liver fibrosis is reduced in VWF-deficient mice, but it is unclear if VWF plays a pathologic role in all settings of liver fibrosis. Indeed, several studies suggest an anti-fibrotic role for components of the hemostatic system, including platelets, in experimental settings of bile duct fibrosis. However, the role of VWF in this specific pathology has not been examined. We tested the hypothesis that VWF exerts hepatoprotective effects in experimental bile duct injury. Wild-type and VWF-deficient (VWF^-/-) mice were challenged with the bile duct toxicant alpha-naphthylisothiocyanate (ANIT) and the impact of VWF deficiency on acute cholestatic liver injury and chronic liver fibrosis was determined. Acute ANIT (60 mg/kg, po)-induced cholestatic liver injury was associated with increased VWF plasma antigen and activity levels. VWF deficiency enhanced ANIT-induced hepatocellular injury, evidenced by increased plasma ALT activity and area of hepatocellular necrosis. Surprisingly, platelet accumulation within necrotic areas was increased in ANIT-challenged VWF^-/- mice compared to wild-type mice. Compared to acute ANIT challenge, hepatic platelet accumulation was modest and appeared to be VWF-dependent in mice exposed to ANIT diet (0.05 %) for 6 weeks. However, contrasting the role of VWF after acute ANIT challenge, VWF deficiency did not impact biliary fibrosis induced by chronic ANIT exposure. The results suggest that VWF plays dichotomous roles in experimental acute and chronic ANIT-induced cholestatic liver injury.

Real-World Management of Patients with Primary Biliary Cholangitis-A Retrospective Study from a Tertiary Medical Center in Israel

Background: Primary biliary cholangitis (PBC) is a rare autoimmune liver disease with variation in prevalence, phenotype and prognosis across different geographical regions. Little is known about PBC in Israel. Our aim was to characterize the demography, clinical presentation, treatment patterns and prognosis in a cohort of PBC patients followed in a referral center in central Israel. Methods: Clinical, demographic and laboratory data were collected from the medical records of PBC patients followed at Tel Aviv Medical Center in the years 2003–2020. Results: We have identified 189 patients with a confirmed diagnosis of PBC; 92.6% were female and the mean age at diagnosis was 54.7 years. Thirty-nine percent were diagnosed with another autoimmune disease and 5.9% were diagnosed with a PBC-AIH (autoimmune hepatitis) variant syndrome. Ninety-six percent were treated with ursodeoxycholic acid (UDCA) at a mean dose of 13.3 mg/kg. A total of 28.1% were found with inadequate response to UDCA according to the Toronto criteria, and 53% of the UDCA non-responders were treated with bezafibrate. Younger age at diagnosis, higher baseline levels of alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT), AIH-PBC variant and positive anti-smooth muscle antibodies (ASMA) were associated with an inadequate UDCA response. In a multivariable analysis, higher ALP at diagnosis (OR = 1.92 CI 1.11–3.20 per 50-unit change, p = 0.018) and ASMA (OR = 27.6 CI 2.58–295, p = 0.006) independently predicted inadequate UDCA response. Higher alanine transaminase (ALT), ALP and GGT, lower albumin, younger age at diagnosis and pruritus conferred an increased risk for disease progression. Conclusions: Disease characteristics, treatment patterns, response to therapy and prognosis of a PBC patient cohort in a tertiary center in central Israel were revealed. The results highlight the importance of risk stratification in PBC, specifically in younger patients, those presenting with a high level of liver enzymes and in ASMA-positive patients with an assumed diagnosis of the AIH-PBC variant.