Epidemiology and liver transplantation burden of primary biliary cholangitis: a retrospective cohort study

A population-based characterization study of anti-mitochondrial M2 antibodies and its consistency with anti-mitochondrial antibodies

OBJECTIVE

This study aims to estimate the prevalence of anti-mitochondrial antibody subtype M2 (AMA-M2) and assess its consistency with AMA in a general population.

METHODS

A total of 8954 volunteers were included to screen AMA-M2 using enzyme-linked immunosorbent assay. Sera with AMA-M2 >50 RU/mL were further tested for AMA using an indirect immunofluorescence assay.

RESULTS

The population frequency of AMA-M2 positivity was 9.67%, of which 48.04% were males and 51.96% were females. The AMA-M2 positivity in males had a peak and valley value of 7.81% and 16.88% in those aged 40 to 49 and ≥70 years, respectively, whereas it showed a balanced age distribution in females. Transferrin and immunoglobulin M were the risk factors for AMA-M2 positivity and exercise was the only protective factor. Of 155 cases with AMA-M2 >50 RU/mL, 25 cases were AMA-positive, with a female-to-male ratio of 5.25:1. Only 2 people, with very high AMA-M2 of 760 and >800 RU/mL, met the diagnostic criteria of primary biliary cholangitis (PBC), making the prevalence of PBC 223.36 per million in southern China.

CONCLUSION

We found that AMA-M2 has a low coincidence rate with AMA in the general population. A new decision-making point for AMA-M2 is needed to improve consistency with AMA and diagnostic accuracy.

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.

Linking Human Betaretrovirus with Autoimmunity and Liver Disease in Patients with Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by the production of diagnostic antimitochondrial antibodies (AMA) reactive to the pyruvate dehydrogenase complex. A human betaretrovirus (HBRV) resembling mouse mammary tumor virus has been characterized in patients with PBC. However, linking the viral infection with the disease is not a straight-forward process because PBC is a complex multifactorial disease influenced by genetic, hormonal, autoimmune, environmental, and other factors. Currently, PBC is assumed to have an autoimmune etiology, but the evidence is lacking to support this conjecture. In this review, we describe different approaches connecting HBRV with PBC. Initially, we used co-cultivation of HBRV with biliary epithelial cells to trigger the PBC-specific phenotype with cell surface expression of cryptic mitochondrial autoantigens linked with antimitochondrial antibody expression. Subsequently, we have derived layers of proof to support the role of betaretrovirus infection in mouse models of autoimmune biliary disease with spontaneous AMA production and in patients with PBC. Using Hill’s criteria, we provide an overview of how betaretrovirus infection may trigger autoimmunity and propagate biliary disease. Ultimately, the demonstration that disease can be cured with antiviral therapy may sway the argument toward an infectious disease etiology in an analogous fashion that was used to link H. pylori with peptic ulcer disease.

Clinical characterization of patients with primary biliary cholangitis: A report from multiple Canadian centres

BACKGROUND

Primary biliary cholangitis (PBC) is a rare, chronic autoimmune, cholestatic liver disease affecting approximately 318 per million Canadians. There is limited information regarding the characterization of this patient population in Canada. Consequently, we aim to describe a cohort of PBC patients managed across liver centres serving this type of population.

METHODS

A cross-sectional examination of 1,125 PBC patient charts at 15 liver centres across Canada was conducted between January 2016 and September 2017.

RESULTS

Data from 1,125 eligible patients were collected from 7 Canadian provinces. The patient population was largely female (90.2%), had a median overall age of 61.3 years, and a median overall time since diagnosis of 6.4 years. Of the patients included in the study, 89% were on ursodeoxycholic acid (UDCA) therapy at a median dose of 14.0 mg/kg/day and 4.4% were previously treated with UDCA, whereas 6.6% were never treated with UDCA. Of the patients with available data (n = 1067), 289 (27.1%) presented with alkaline phosphatase (ALP) levels ≥200 IU/L and/or total bilirubin levels ≥21 µmol/L. Assessment of UDCA treatment response revealed that 26.6% and 38.3% of patients were inadequate responders according to the Toronto and Paris-II criteria, respectively. Mortality occurred in 1.2% (14) of patients, with liver-related adverse outcomes being more commonly observed in patients who discontinued UDCA compared to those who are currently on treatment (36.3% and 19.6%, respectively).

CONCLUSION

This study showed that Canadian PBC patients present with demographics and features commonly reported in the literature for this disease. Over one third of PBC patients had inadequate response to UDCA treatment or were not currently being treated with UDCA. Consequently, there is a significant unmet therapeutic need in this Canadian PBC population.

Regional variation and temporal trend of primary biliary cholangitis epidemiology: A systematic review and meta-analysis

BACKGROUND AND AIM

We aimed to estimate the worldwide incidence and prevalence, with focus on the geographical differences and temporal trends.

METHODS

Studies on epidemiology of primary biliary cholangitis (PBC) in PubMed, Embase, and Cochrane Library were systematically retrieved from inception to October 2, 2020. Random-effect model was applied to estimate the pooled PBC incidence and prevalence rates. Subgroup analysis, meta-regression, and sensitivity analysis were conducted to find out the cause for heterogeneity.

RESULTS

Out of 3974 records identified through database searching, 47 population-based studies were finally included. The pooled global incidence and prevalence of PBC were 1.76 and 14.60 per 100 000 persons, respectively. Both the PBC incidence and prevalence were lower in the Asia-Pacific region (0.84, 9.82 per 100 000 persons) than that in North America (2.75, 21.81 per 100 000 persons) and Europe (1.86, 14.59 per 100 000 persons) (P < 0.05). The incidence and prevalence showed an increasing tendency in all three regions, with the fastest growth of prevalence in North America (P < 0.05). We found a similar incidence and a lower prevalence of PBC in Northern Europe than that in Southern Europe. A higher incidence and prevalence were observed in female individuals and in the elderly (60-79).

CONCLUSION

The PBC incidence and prevalence varied widely across regions, with North America being the highest, followed by Europe, and the lowest in the Asia-Pacific region. Both the incidence and prevalence showed an increasing tendency worldwide, especially in North America.

Identification of the Representative Primary Biliary Cholangitis Cohort in Taiwan: A Comparison of Four Nationwide Cohorts

BACKGROUND/PURPOSE

The rates and outcomes of primary biliary cholangitis (PBC) in Taiwan remain unclear.

METHODS

A nationwide population-based cohort study (Taiwan National Health Insurance Research Database, 2002-2015) was conducted. Data from four PBC cohorts with various definitions were compared (cohort 1 (C1): ICD-9-CM (571.6); C2: alkaline phosphatase (Alk-P) and antimitochondrial antibody (AMA) measurements; C3: Alk-p and AMA measurements and ursodeoxycholic acid (UDCA) treatment; C4: ICD-9-CM (571.6), Alk-p and AMA measurements and UDCA treatment).

RESULTS

The average prevalence rate ranged from 9.419/10⁵ (C4) to 307.658/10⁵ (C2), and the female-to-male ratio ranged from 1.192 (C1) to 3.66 (C4). Prevalence rates increased over time in all cohorts. The average incidence rates ranged from 1.456/10⁵ (C4) to 66.386/10⁵ (C2). Incidence rates decreased over time in C1 (-9.09%, p < 0.0001) and C4 (-6.68%, p < 0.0001) and remained steady in the others. C4 had the lowest prevalence and incidence rates and highest female-to-male ratio. Cirrhosis rates ranged from 7.21% (C2) to 39.34% (C4), hepatoma rates ranged from 2.77%(C2) to 6.66%(C1), liver transplantation (LT) rates ranged from 1.07% (C2) to 6.77% (C4), and mortality rates ranged from 18.24% (C2) to 47.36% (C1). C4 had the highest LT (6.77%), osteoporosis (13.87%) and dyslipidemia rates (17.21%).

CONCLUSIONS

Based on the reported ranges of reasonable rates, female predominance and characteristic outcomes, C4 was the most representative Taiwanese PBC cohort, with average prevalence and incidence rates of 9.419/10⁵ and 1.456/10⁵, respectively, and a female-to-male ratio of 3.66. In a 14-year period, cirrhosis, hepatoma, LT, and mortality were noted in 39.34%, 5.52%, 6.77%, and 34.22% of C4 patients, respectively.

Review article: pathophysiology and management of primary biliary cholangitis

BACKGROUND

Primary biliary cholangitis (PBC), an immune-mediated disease characterised by destruction of intrahepatic bile ducts, results in progressive damage to the biliary tree, cholestasis and ultimately advanced liver disease. In the last decade, advances in practice have improved clinical care, driven novel therapeutic options and improved risk stratification tools.

AIMS

To provide an overview of the disease characteristics of PBC and review a patient-centred management approach for the clinical team caring for those with PBC.

METHODS

We reviewed the current literature and guidelines on PBC with a focus on management and therapies.

RESULTS

A confident diagnosis of PBC is usually made based on serum liver tests and immune serology. Management of PBC should focus on three main 'process' pillars: (a) treat and risk-stratify through use of biochemical and prognostic criteria; (b) manage concurrent symptoms and other associated diseases; and (c) stage disease, monitor progression and prevent complications. With ongoing complexities in management, including a newly licensed therapy (obeticholic acid) and alternative non-licensed treatments and ongoing clinical trials, discussion with PBC expert centres is encouraged.

CONCLUSIONS

PBC is a dynamic disease wherein current treatment goals have become appropriately ambitious. Goals of care should prioritise prevention of end-stage liver disease and amelioration of patient symptom burden for all.

Real-World Effectiveness of Obeticholic Acid in Patients with Primary Biliary Cholangitis

Patients with primary biliary cholangitis (PBC) with incomplete response to ursodeoxycholic acid are at risk of disease progression and need additional therapy. Obeticholic acid (OCA) was approved in Canada in May 2017, but its effectiveness in a real‐world setting has not been described. We sought to describe our experience with OCA in a Canadian cohort. OCA‐naive patients treated at two Canadian centers were included. Clinical and biochemical data were collected at OCA initiation and during follow‐up. Primary outcomes were changes in serum alkaline phosphatase (ALP), gamma‐glutamyl transferase (GGT), and total bilirubin (TB) over the duration of therapy. Secondary outcomes were changes in alanine aminotransferase (ALT), aspartate aminotransferase (AST), immunoglobulin M (IgM), platelets, and albumin; and achievement of the primary endpoint of the original phase 3 study that led to OCA approval (A Placebo‐Controlled Trial of Obeticholic Acid in Primary Biliary Cholangitis [POISE]), dose reductions, discontinuations, and tolerability. Repeated‐measures models were used to assess changes in biochemistry over time. Sixty‐four patients were included; 4 carried a diagnosis of overlap with autoimmune hepatitis. Mean age was 54.6 years, median ALP was 250 U/L, TB was 13 µmol/L, platelet count was 225 × 10⁹/L, and 24% had liver stiffness measurements ≥16.9 kPa. There was a significant reduction in mean ALP of 55 U/L (P < 0.001), GGT of 138 U/L (P < 0.001), ALT of 11.9 U/L (P < 0.001), AST of 5.7 U/L (P < 0.05), and IgM of 0.70 g/L (P < 0.001) over 12 months; TB remained stable (P = 0.98). Forty‐four patients met POISE‐inclusion criteria, 39% (n = 17) of whom had 12‐month biochemical measurements. In this subset, 18% (n = 3/17) met the 12‐month POISE primary endpoint, but considering follow‐up to 19 months, 43% achieved this target (n = 9/21). Pruritus was the most commonly reported complaint. Conclusion: Use of OCA was associated with improvement in biochemical surrogates of outcome in PBC in a real‐world setting.

Race/Ethnicity and Insurance-Specific Disparities in In-Hospital Mortality Among Adults with Primary Biliary Cholangitis: Analysis of 2007-2014 National Inpatient Sample

BACKGROUND

Primary biliary cholangitis (PBC) is a progressive autoimmune liver disease that can result in cirrhosis and end-stage liver disease.

AIMS

We aim to evaluate hospitalization burden and in-hospital mortality among PBC patients in the USA.

METHODS

Using data from the Nationwide Inpatient Sample from 2007 to 2014, hospitalizations among US adults with PBC were stratified by sex, age, and race/ethnicity. Overall in-hospital mortality was stratified by these variables and adjusted multivariate regression models evaluated for predictors of in-hospital mortality.

RESULTS

From 2007 to 2014, there were 18,279 hospitalizations among adults with PBC (15.0% male, mean age 63.8 years, 41.3% cirrhosis). Among non-Hispanic whites, the proportion of total PBC hospitalizations increased from 57.8% in 2007 to 71.2% in 2014, compared to 4.1-6.3% for African-Americans, 8.6-10.9% for Hispanics, and 1.7-2.8% for Asians (p < 0.001 for all). While overall in-hospital mortality was low (4.2%), increasing age was associated with higher odds of in-hospital mortality (OR: 1.02, 95% CI 1.01-1.03, p < 0.001). Compared to non-Hispanic white PBC patients, higher in-hospital mortality was observed in African-American PBC patients (OR: 1.40, 95% CI 1.16-2.03, p < 0.05). Compared to patients with private/commercial insurance, significantly higher odds of in-hospital mortality were observed in patients with Medicaid insurance (OR 1.42, 95% CI 1.00-1.99, p < 0.05).

CONCLUSION

In summary, among adults with PBC hospitalized in the USA from 2007 to 2014, the overall number of hospitalizations is increasing. Significant disparities in in-hospital mortality were observed; African-Americans with PBC and Medicaid patients with PBC have disproportionately higher odds of in-hospital mortality.

Epidemiology and clinical course of primary biliary cholangitis in the Asia-Pacific region: a systematic review and meta-analysis

AIMS

Epidemiological studies on primary biliary cholangitis (PBC) show heterogeneity. The aim of the present study was to synthesize the prevalence, incidence and clinical course of PBC in the Asia-Pacific region.

METHODS

PubMed, Medline, Cochrane library and EMBASE were searched for epidemiology and clinical course of PBC published up to July, 2019. Meta-analysis was conducted on the epidemiology and clinical course (decompensation, hepatocellular carcinoma and death/liver transplantation) of PBC patients. Random-effect model and fixed-effect model were used to evaluate the pooled prevalence, incidence, mortality/liver transplantation and their 95% confidence intervals as appropriate. Subgroup analysis was performed by stratification with gender, pre- and post-UDCA era, sub-region and publication year. Meta-regression was used to examine the heterogeneity.

RESULTS

Out of 3460 studies, 18 studies from 7 countries/regions were finally included. The overall prevalence of PBC was 118.75 cases per million (95% CI 49.96-187.55) in the Asia-Pacific region, with the high, medium and low prevalence being in Japan and China (191.18 cases per million), New Zealand (99.16 cases per million) and South Korea and Australia (39.09 cases per million), respectively. The incidence of PBC was 8.55 cases per million per year (95% CI 8.05-9.06). The 5-year accumulative incidence of decompensation, HCC and death/liver transplantation in PBC patients was 6.95% (95% CI 2.07-11.83%), 1.54% (95% CI 0.9-2.19%) and 4.02% (95% CI 2.49-5.54%), respectively.

CONCLUSION

In the Asia-Pacific region, the prevalence and incidence of PBC are higher than once expected. PBC tends to be diagnosed at older age and has a relatively low incidence of HCC in this region.

Increase trend in the prevalence and male-to-female ratio of primary biliary cholangitis, autoimmune hepatitis, and primary sclerosing cholangitis in Japan

AIM

Autoimmune liver diseases (AILD) including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) impose a significant burden on public health, and it is important to estimate their prevalence. We carried out a nationwide, hospital-based, epidemiological survey of AIH, PBC, and PSC, and compared the results with those from previous surveys.

METHOD

We randomly selected health-care facilities used in the survey from a list of all facilities in Japan. The selection rate was determined according to a stratification based on the facility characteristics and scale. We sent questionnaires to the selected facilities enquiring about the number and sex of patients with AILD who visited the facility in 2016. An identical survey was undertaken for AIH/PBC in 2004 and for PSC in 2007; we carried out a comparative analysis of these data.

RESULTS

We selected 1793 departments from health centers all over Japan. Of them, 1078 (60.1%) responded to the questionnaires. The number of reported patients with AIH, PBC, and PSC was 8505, 10 847, and 906, respectively, and point prevalence was 23.9 (95% confidence interval, 23.3-24.5) for AIH (8.7 in 2004), 33.8 (33.0-34.6) for PBC (11.6 in 2004), and 1.80 (1.75-1.85) for PSC (0.95 in 2007) per 100 000 population. Male-to-female patient ratio of AILD was 1:4.3 for AIH (1:6.9 in 2004), 1:3.9 for PBC (1:7.1 in 2004), and 1:0.88 for PSC (1:1.4 in 2007).

CONCLUSION

The current study indicates an increasing trend of prevalence as well as male-to-female patient ratio of AILD in Japan.