Increasing prevalence of primary biliary cholangitis in Victoria, Australia

A nationwide study of primary biliary cholangitis prevalence, geographic distribution, and health care providers

BACKGROUND

Prevalence estimates of primary biliary cholangitis (PBC) in the United States have evolved with the introduction of newer real-world data capture approaches. Little is known about the geographic distribution of PBC in the United States and the health care provider (HCP) landscape for patients with PBC. This real-world study aimed to estimate the prevalence of PBC in the United States, assess regional variability in its prevalence, and describe HCPs for patients with PBC.

METHODS

Patients with PBC were identified using Komodo's Healthcare Map, a large national administrative claims database. PBC prevalence per 100,000 adults was adjusted by age and gender at the 3-digit ZIP Code tabulation area level. Patients' PBC-related medical or pharmacy claims were used to determine HCP specialties and affiliations (academic vs. nonacademic); the latest claim and all claims were examined.

RESULTS

The adjusted 2021 PBC prevalence was 40.9 per 100,000 adults. The highest absolute number of patients with PBC in the United States was in heavily populated urban areas, but prevalence adjusted for population size was highest in some rural areas. Among all claims, most (83.2%) patients received care from a specialist (gastroenterologist/hepatologist) at one time. However, only approximately half (53.5%) of patients with PBC, irrespective of therapy use, were most recently treated for PBC by a specialist.

CONCLUSIONS

This is the most comprehensive and contemporary estimation of PBC prevalence in the United States to date. The pockets of high prevalence of PBC located in some rural areas highlight the need to better evaluate PBC risk factors and potential barriers in access to specialist care once patients are diagnosed. Greater awareness of PBC and its management are needed.

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.

Efficacy and safety of pharmacological interventions for pruritus in primary biliary cholangitis: A systematic review and meta-analysis

Background and objective: Pruritus is a common complication in patients with primary biliary cholangitis (PBC). The pathogenesis is not clear, and also the precise therapeutic measures remain alluring. In order to systematically evaluate the efficacy and safety of drug interventions in the treatment of pruritus associated with PBC, this systemic review and meta-analysis was conducted.

Methods: The randomized controlled trials (RCTs) on drug interventions in the treatment of pruritus associated with primary cholangitis were searched in the electronic databases of PubMed, EMBASE, Cochrane Library, Web of Science, and ClinicalTrials.gov. Two researchers independently screened the literature, extracted and integrated the data, and assessed the bias risk of the selected literature, according to the Cochrane handbook. Finally, the STATA 15.0 software was used for the meta-analysis.

Results: A total of 23 RCTs involving 2,194 patients were studied, that included 12 pharmacological interventions. In terms of itching relief, compared with placebo, UDCA, methotrexate and GSK2330672 had a definite effect in improving pruritus (pruritus remission rate before and after treatment, p < 0.05). In terms of serum indexes, compared with placebo group, UDCA, OCA, rifampicin, cyclosporine, NGM282, seladelpar and colchicine may improve blood alkaline phosphatase (ALP) (p < 0.05), but only rifampicin showed low heterogeneity. UDCA, bezafibrate, OCA, rifampicin, NGM282 and others may improve blood γ-glutamyl transpeptidase (γ-GGT) (p < 0.05), but due to the high heterogeneity and the limitation of research samples, a clear conclusion cannot be drawn. In terms of adverse events, except high (>15 mg/kg/day) and low doses (<13 mg/kg/day) of UDCA increased the incidence of adverse events, there were no risk of increasing the incidence of adverse events compared with placebo (p > 0.05), and a moderate dose of UDCA (13–15 mg/kg/day) and malotilate (1,500 mg/day) may also help in reducing the incidence of adverse events (p < 0.05).

Conclusion: UDCA, methotrexate and GSK2330672 may relieve itching in patients with PBC, but there is a lack of robust evidence to support their effect on ALP or γ-GGT. Due to the heterogeneity in the published studies, based on the present review, we cannot explicitly recommend any specific drug for the treatment of PBC-related pruritus.

Systematic Review Registration:link-https://osf.io/2g8ya, identifier 10.17605/OSF.IO/2G8YA

Alcohol intake is associated with a decreased risk of developing primary biliary cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic progressive liver disease of unknown aetiology characterised by immune-mediated destruction of small and medium-sized intrahepatic bile ducts. There are few well-established risk factors and epidemiological studies are needed to further evaluate the pathogenesis of the disease.

AIM

To evaluate the relationship between alcohol intake, smoking and marijuana use with PBC development.

METHODS

We conducted a prevalent case control study of 200 cases and 200 age (within a five year age band) and sex-matched controls, identified from the Victorian PBC prevalence study. We assessed lifetime alcohol intake and smoking behaviour (both tobacco and marijuana) prior to PBC onset and used conditional logistic regression for analyses.

RESULTS

Alcohol intake consistently showed a dose-dependent inverse association with case status, and this was most substantial for 21-30 years and 31-40 years (P_trend < 0.001). Smoking was associated with PBC, with a stronger association with a longer duration of smoking [e.g., adjusted OR 2.27 (95%CI: 1.12- 4.62) for those who had smoked for 20-35 years]. There was no association between marijuana use and PBC.

CONCLUSION

Alcohol appears to have an inverse relationship with PBC. Smoking has been confirmed as an environmental risk factor for PBC. There was no association between marijuana use and PBC.

Identification of a Latitude Gradient in the Prevalence of Primary Biliary Cholangitis

INTRODUCTION

The prevalence of primary biliary cholangitis (PBC) reported in different countries varies significantly and seems to have a latitudinal gradient with the highest prevalence reported in higher latitudes, as has been observed with other autoimmune diseases. This study aimed to determine whether there is a latitudinal gradient of PBC prevalence in Australia using 2 methods of case ascertainment.

METHODS

We investigated the latitudinal variation of PBC prevalence across the states and territories of Australia (latitudinal range 18.0°-42.7°S) using pathology-based (private pathology antimitochondrial antibody results and PBC-specific prescription databases (prescriptions for ursodeoxycholic acid, the only publicly subsidized treatment for this disease).

RESULTS

PBC prevalence was significantly positively associated with latitude, and the postcodes in the highest quintile of latitude (encompassing the south coastal areas of the Australian mainland and Tasmania; latitude range -37.75° to -42.72°) had a prevalence estimate that was 1.78 times higher using the pathology-based prevalence estimation than those in the lowest quintile (encompassing tropical and southern Queensland; latitude range -18.02° to -27.59°). Comparing prevalence estimates between states/territories, the result was 2.53 and 2.21 times higher in Tasmania compared with Queensland when using the pathology-based and prescription-based methods, respectively.

DISCUSSION

Using 2 different case-ascertainment methods, we have demonstrated that prevalence estimates of PBC vary significantly with latitude in Australia. Further studies are needed to determine whether factors such as variations in ultraviolet radiation exposure and/or vitamin D levels are responsible for this observation and to investigate the latitudinal prevalence of PBC in other populations.

Extrahepatic autoimmune diseases in primary biliary cholangitis: Prevalence and significance for clinical presentation and disease outcome

BACKGROUND AND AIM

The prevalence and clinical significance of extrahepatic autoimmune diseases (EHAIDs) have not been evaluated in a large cohort of primary biliary cholangitis (PBC).

METHODS

The medical records of 1554 patients with PBC from 20 international centers were retrospectively reviewed. Development of decompensated cirrhosis (ascites, variceal bleeding, and/or hepatic encephalopathy) and hepatocellular carcinoma were considered clinical endpoints.

RESULTS

A total of 35 different EHAIDs were diagnosed in 440 (28.3%) patients with PBC. Patients with EHAIDs were more often female (92.5% vs 86.1%, P < 0.001) and seropositive for anti-mitochondrial antibodies (88% vs 84%, P = 0.05) and antinuclear antibodies and/or smooth muscle antibodies (53.8% vs 43.6%, P = 0.005). At presentation, patients with EHAIDs had significantly lower levels of alkaline phosphatase (1.76 vs 1.98 × upper limit of normal [ULN], P = 0.006), aspartate aminotransferase (1.29 vs 1.50 × ULN, P < 0.001), and total bilirubin (0.53 vs 0.58 × ULN, P = 0.002). Patients with EHAIDs and without EHAIDs had similar rates of GLOBE high-risk status (12.3% vs 16.1%, P = 0.07) and Paris II response (71.4% vs 69.4%, P = 0.59). Overall, event-free survival was not different in patients with and without EHAIDs (90.8% vs 90.7%, P = 0.53, log rank). Coexistence of each autoimmune thyroid diseases (10.6%), Sjögren disease (8.3%), systemic sclerosis (2.9%), rheumatoid arthritis (2.7%), systemic lupus erythematosus (1.7%), celiac disease (1.7%), psoriasis (1.5%), and inflammatory bowel diseases (1.3%) did not influence the outcome.

CONCLUSIONS

Our study confirms that EHAIDs are frequently diagnosed in patients with PBC. The presence of EHAIDs may influence the clinical phenotype of PBC at presentation but has no impact on PBC outcome.

Current understanding of primary biliary cholangitis

Primary biliary cholangitis (PBC) causes chronic and persistent cholestasis in the liver, eventually resulting in cirrhosis and hepatic failure without appropriate treatment. PBC mainly develops in middle-aged women, but it is also common in young women and men. PBC is considered a model of autoimmune disease because of the presence of disease-specific autoantibodies, that is, antimitochondrial antibodies (AMAs), intense infiltration of mononuclear cells into the bile ducts, and a high prevalence of autoimmune diseases such as comorbidities. Histologically, PBC is characterized by degeneration and necrosis of intrahepatic biliary epithelial cells surrounded by a dense infiltration of mononuclear cells, coined as chronic non-suppurative destructive cholangitis, which leads to destructive changes and the disappearance of small- or medium-sized bile ducts. Since 1990, early diagnosis with the detection of AMAs and introduction of ursodeoxycholic acid as first-line treatment has greatly altered the clinical course of PBC, and liver transplantation-free survival of patients with PBC is now comparable to that of the general population.