Update on the epidemiology of primary biliary cirrhosis

Clinical Updates in Primary Biliary Cholangitis: Trends, Epidemiology, Diagnostics, and New Therapeutic Approaches

Primary biliary cholangitis, formerly known as primary biliary cirrhosis, is a chronic, autoimmune, and cholestatic disease ameliorating the biliary epithelial system causing fibrosis and end-stage liver disease, over time. Patients range from an asymptomatic phase early in the disease course, to symptoms of decompensated cirrhosis later in its course. This review focuses on the current consensus on the epidemiology, diagnosis, and management of patients with primary biliary cholangitis. We also discuss established medical management as well as novel and investigational therapeutics in the pipeline for management of PBC.

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

BACKGROUND

There is a wealth of data documenting the epidemiology of primary biliary cholangitis (PBC) globally; however, the epidemiology of PBC has not been as well studied in Canada. Our study characterized the Canadian prevalence of PBC and the number of liver transplantations because of PBC.

METHODS

For this retrospective cohort study we used national hospital administrative records from the Canadian Institute for Health Information, with the exception of Quebec for the prevalence estimate and Quebec and British Columbia for the transplant analysis. Prevalent patients were identified through a diagnostic code for PBC of the Canadian version of the 10th revision of the International Classification of Diseases. PBC transplant patients were identified from their transplant record. Descriptive statistics were used to summarize the characteristics of the study cohorts.

RESULTS

In 2015, 8680 patients with PBC were identified in Canada, translating to a prevalence of 318 cases per million. Annual prevalence by province varied, ranging from 283 (95% confidence interval [CI] 269-297) cases per million to 465 (95% CI 426-504) cases per million, and the 6-year PBC liver transplantation rate ranged from 3.17 (95% CI 1.27-6.54) to 5.92 (95% CI 3.71-9.08) per million. The Atlantic provinces exhibited the highest PBC prevalence and close to the highest 6-year liver transplantation rate (465 [95% CI 426-504] cases per million and 5.70 [95% CI 426-504, 3.19-9.56] cases per million, respectively). We observed the lowest PBC prevalence (283 [95% CI 269-297] cases per million) and the second lowest 6-year liver transplantation rate in Ontario (3.37 [95% CI 2.47-4.50] cases per million).

INTERPRETATION

The prevalence of PBC that we found in Canada is similar to the prevalence reported in other studies, but our work also indicates geographic variation within this country. Given our finding of geographic clustering of PBC across Canada, we hypothesize that environmental and genetic factors contribute to the pathogenesis of this condition.

Underestimated Male Prevalence of Primary Biliary Cholangitis in China: Results of a 16-yr cohort study involving 769 patients

For primary biliary cholangitis (PBC), a sex ratio was reported to be significantly lower than previously cited in the West; we sought to evaluate sex ratio and long-term outcomes in PBC by studying a PBC cohort at a high-volume hospital from January 2001 to July 2016. A retrospective analysis including 769 PBC patients was conducted. The gender ratio was 6.1:1. Of the patients, 30.6% had one or more extrahepatic autoimmune (EHA) conditions. The proportion of patients with decompensated PBC at diagnosis increased from 25.0% in period 1 to 47.0% in period 4 (p < 0.05). Of the 420 patients without complications on presentation, the Kaplan-Meier estimate revealed distinct outcomes between non-cirrhotic PBC and cirrhotic PBC, with estimated mean survival times of 145.1 months and 104.5 months, respectively (p < 0.001). According to a subgroup analysis, gender and anti-mitochondrial antibody (AMA) status did not affect long-term prognosis, whereas patients with EHA conditions showed better prognoses. This study reveals evolving trends in male prevalence similar to their Western counterparts. Cirrhotic PBC patients were distinct from those with non-cirrhotic PBC at diagnosis based on difference in long-term outcome.