Incidence, prevalence and clinical course of primary biliary cirrhosis in a Spanish community

Retrieval and treatment of patients with primary biliary cholangitis who are lost in the health system

INTRODUCTION

hepatitis C patients loss to follow-up in the health care system has been shown to have negative consequences. This study aimed to investigate this issue as regards primary biliary cholangitis.

METHODS

the databases (immunology, biochemistry, clinical reports, drug dispensation, appointments) of 4 reference hospitals in Spain (serving a population of 1,450,000 inhabitants) were analyzed. The diagnosis of primary biliary cholangitis was based on an antimitochondrial antibody titer ≥ 1:80, chronically elevated alkaline phosphatase, and the absence of other liver disease. Patients were classified as lost in the absence of reports indicating a diagnosis, specific medical follow-up, and/or treatment with bile salts.

RESULTS

a total of 1372 patients with antimitochondrial antibody titers ≥ 1:80 were included between January 2010 and June 2019. A total of 697 (50.8 %) were classified as having primary biliary cholangitis, and 100 patients (14.3 %; 95 % CI: 11.8-17.2) were identified as lost. Of these, 30 were contacted and retrieved. The median age was 70 years, 93 % were female, median alkaline phosphatase was 185 IU/L, 10 % had pruritus, and 27 % had a transient elastography value > 9.5 kPa. The disease was confirmed and ursodeoxycholic acid was started in all 30 patients. Death was liver-related in 6 of the 100 patients classified as lost.

CONCLUSION

up to 14.3 % of patients (1 out of 7) with a definitive diagnosis of primary biliary cholangitis remain undiagnosed, thus preventing monitoring and treatment. More than a quarter are at risk of advanced liver disease and its complications. Patients lost in the system must be identified and retrieved, and searching hospital databases is a suitable approach to meet this goal.

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

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic autoimmune cholestatic liver disease with wide ranges of reported incidence and prevalence.

AIM

To map the incidence and prevalence of PBC in European countries from 2000 through 2020.

METHODS

Following PRISMA recommendations, we searched the Medline and Scopus databases for studies with information on either the incidence or prevalence of PBC. After data extraction, we used a random-effects model to estimate both the pooled annual incidence rate and pooled point-prevalence rate and performed subgroup analyses to identify components contributing to between-study heterogeneity.

RESULTS

We performed a qualitative and quantitative analysis of 18 studies. The pooled point-prevalence rate was 22.27 cases per 100,000 inhabitants (95% CI: 17.98-27.01), and the pooled annual incidence rate was 1.87 new cases per 100,000 inhabitants (95% CI: 1.46-2.34). In the subgroup analyses, we proved that a small part of the between-study heterogeneity is significantly associated with a history of being part of the Eastern Bloc.

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.

Epidemiology and clinical course of primary biliary cholangitis in Eastern Slovakia

OBJECTIVE

To determine both the incidence and the prevalence of primary biliary cholangitis (PBC) in Eastern Slovakia and to describe its clinical course and the response to ursodeoxycholic acid (UDCA).

METHODS

We recorded data of patients with PBC, who were followed up in gastroenterology and hepatology centers in Eastern Slovakia during the period from June 30, 1999, through June 30, 2019.

RESULTS

The annual incidence of PBC varied from 0.7 to 1.5 cases per 100,000 inhabitants between 2014 and 2018. PBC prevalence steadily increased from initial 10.2 cases per 100,000 inhabitants in 2014 to 14.9 cases per 100,000 inhabitants in June 2019. The mean age at the time of diagnosis was 56.3 ± 10.9 years. 95.7% of patients were females, and female/male gender ratio was 22.3:1. In June 2019, prevalence in the female population was 28 cases per 100,000 women. At the time of diagnosis, three-quarters of patients were symptomatic and 10% of patients had liver cirrhosis. The mean follow-up was 7.3 ± 5.2 years. Response to UDCA was observed in 72.1% of patients. Patients with higher baseline alkaline phosphatase (ALP) levels, liver cirrhosis at entry or at the end of follow-up and women younger than 45 years responded worse to UDCA. One-quarter of patients had liver cirrhosis at the end of follow-up. During follow-up, 1.6% of patients underwent liver transplantation and 5.5% of patients died. Five-year and 10-year liver-related mortalities were 2.7% and 4.3%, respectively.

CONCLUSION

PBC prevalence in Eastern Slovakia is increasing, and most of the patients respond to therapy with UDCA.

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.

Primary biliary cholangitis in Spain. Results of a Delphi study of epidemiology, diagnosis, follow-up and treatment

INTRODUCTION

primary biliary cholangitis (PBC) is a rare disease with limited data regarding its epidemiology and standard clinical management in Spain.

OBJECTIVE

to gain insight into the epidemiology, patient flow, diagnosis, follow-up and treatment of PBC in Spain.

METHODS

a review of the literature and Delphi study involving 28 specialists in two rounds of consultations and an in-person results validation workshop.

RESULTS

there are approximately 9,400 patients with PBC in Spain, with an annual incidence of 0.51-3.86 cases/100,000 population. Albeit, a high error margin may be presumed due to the scarcity of relevant studies on this subject. Several months may elapse from suspicion to a confirmed diagnosis, usually by a gastroenterologist or hepatologist. The role of the liver biopsy for diagnosis and follow-up is heterogeneous. Overall, 95% of patients are treated with ursodeoxycholic acid (UDCA) and response is primarily monitored using the Barcelona criteria. Follow-up is performed every six months, with a heterogeneous use of the various available techniques. No recommendations or second-line commercial drugs are available in the case of no response, inadequate response or intolerance to UDCA.

CONCLUSIONS

while epidemiology may be estimated based on expert opinions, national registries are needed to provide accurate, up-to-date information on epidemiological parameters, disease stage and response to treatment in patients with PBC. Furthermore, novel therapies are required for selected patient groups.

The British Society of Gastroenterology/UK-PBC primary biliary cholangitis treatment and management guidelines

Primary biliary cholangitis (formerly known as primary biliary cirrhosis, PBC) is an autoimmune liver disease in which a cycle of immune mediated biliary epithelial cell injury, cholestasis and progressive fibrosis can culminate over time in an end-stage biliary cirrhosis. Both genetic and environmental influences are presumed relevant to disease initiation. PBC is most prevalent in women and those over the age of 50, but a spectrum of disease is recognised in adult patients globally; male sex, younger age at onset (<45) and advanced disease at presentation are baseline predictors of poorer outcome. As the disease is increasingly diagnosed through the combination of cholestatic serum liver tests and the presence of antimitochondrial antibodies, most presenting patients are not cirrhotic and the term cholangitis is more accurate. Disease course is frequently accompanied by symptoms that can be burdensome for patients, and management of patients with PBC must address, in a life-long manner, both disease progression and symptom burden. Licensed therapies include ursodeoxycholic acid (UDCA) and obeticholic acid (OCA), alongside experimental new and re-purposed agents. Disease management focuses on initiation of UDCA for all patients and risk stratification based on baseline and on-treatment factors, including in particular the response to treatment. Those intolerant of treatment with UDCA or those with high-risk disease as evidenced by UDCA treatment failure (frequently reflected in trial and clinical practice as an alkaline phosphatase >1.67 × upper limit of normal and/or elevated bilirubin) should be considered for second-line therapy, of which OCA is the only currently licensed National Institute for Health and Care Excellence recommended agent. Follow-up of patients is life-long and must address treatment of the disease and management of associated symptoms.

Geoepidemiology and (epi-)genetics in primary biliary cholangitis

Primary biliary cholangitis (PBC) is a rare female preponderant chronic autoimmune cholestatic liver disease, characterized by intrahepatic ductopenia and progressive fibrosis. During last decades incidence and prevalence showed an increasing rate which vary widely worldwide demonstrating an important interaction between environmental and genetic factors. Heritability suggested by familial occurrence and monozygotic twins concordance have been confirmed in more studies. Epigenetics mechanisms such as histone modification and DNA methylation can partially explain predisposition and inheritance of this disease. Nevertheless, an association with specific class II human leukocyte antigen (HLA) variants have been reported, showing an increase risk in susceptibility. More recently, data regarding a strong protective association between PBC and HLA alleles confirmed this association. After recent genome-wide association studies (GWAS), a more intricate interaction between PBC and the HLA region has been shown. Furthermore, GWAS also identified several immune-related-genes implicated. More genome-wide association studies on this disease are needed to reach a complete and systematic knowledge of this disease. In this review we discuss more recent issued data on geoepidemiology of PBC and the role of (epi-)genetic mechanisms in its pathogenesis.

Milder disease stage in patients with primary biliary cholangitis over a 44-year period: A changing natural history

Changes over time in the presenting features and clinical course of patients with primary biliary cholangitis are poorly described. We sought to describe temporal trends in patient and disease characteristics over a 44-year period across a large international primary biliary cholangitis cohort of 4,805 patients diagnosed between 1970 and 2014, from 17 centers across Europe and North America. Patients were divided into five cohorts according to their year of diagnosis: 1970-1979 (n = 143), 1980-1989 (n = 858), 1990-1999 (n = 1,754), 2000-2009 (n = 1,815), and ≥2010 (n = 235). Age at diagnosis, disease stage, response to ursodeoxycholic acid, and clinical outcomes were compared. Mean age at diagnosis increased incrementally by 2-3 years per decade from 46.9 ± 10.1 years in the 1970s to 57.0 ± 12.1 years from 2010 onward (P < 0.001). The female to male ratio (9:1) and antimitochondrial antibody positivity (90%) were not significantly variable. The proportion of patients presenting with mild biochemical disease (according to Rotterdam staging) increased from 41.3% in the 1970s to 72.2% in the 1990s (P < 0.001) and remained relatively stable thereafter. Patients with a mild histological stage at diagnosis increased from 60.4% (1970-1989) to 76.5% (1990-2014) (P < 0.001). Correspondingly, response to ursodeoxycholic acid according to Paris-I criteria increased; 51.7% in the 1970s and 70.5% in the 1990s (P < 0.001). Recent decades were also characterized by lower decompensation rates (18.5% in the 1970s to 5.8% in the 2000s, P < 0.001) and higher 10-year transplant-free survival (48.4%, 68.7%, 79.7%, and 80.1% for each respective cohort; P < 0.001).

CONCLUSION

In recent decades, a pattern of primary biliary cholangitis presentation consistent with an older age at diagnosis alongside reduced disease severity has been noted; the observed trends may be explained by an increase in routine testing of liver function and/or a changing environmental trigger. (Hepatology 2018;67:1920-1930).

National incidence of autoimmune liver diseases and its relationship with the human development index

Objective

Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), autoimmune hepatitis (AIH) and immunoglobulin G4 related cholangitis represent the major autoimmune liver diseases (AILD). However, the relationship between AILD incidence and socioeconomic development levels is yet to be explored.

Results

A total of 43 studies were included. There was a positive but not significant correlation between the PBC incidence and HDI on a global level (r=0.348, P=0.082). However, in Europe, a significantly positive correlation existed between the PBC incidence and HDI (r=0.455, P=0.044). No statistical correlation between PSC incidence and HDI was observed (r=0.116, P=0.706). The incidence of AIH revealed a positive correlation with the national HDI both globally (r=0.638, P=0.014) and in Europe (r=0.644, P=0.045). Moreover, the PBC incidence demonstrated a positive correlation with the health index (r=0.422, P=0.036), but a negative correlation with the education index (r= −0.650, P<0.01). Moreover, the income index presented a positive correlation with both the PSC incidence (r=0.599, P=0.031) and the AIH incidence (r=0.649, P=0.012).

Methods

PubMed was searched to identify relevant epidemiological studies on AILD. The human development index (HDI) was applied as an indicator for socioeconomic development. HDI data were obtained and calculated based on the 2014 Human Development Report. Pearson coefficient and linear regression analysis were conducted to estimate the correlation between incidence and HDI.

Conclusions

There is positive association between the national incidence of AILD and the socioeconomic status, as measured by HDI. In less-developed countries, the incidence of AILD, especially PBC and AIH, might be less common.

Geoepidemiology and changing mortality in primary biliary cholangitis

Primary biliary cholangitis (PBC), formerly called primary biliary cirrhosis, is a chronic cholestatic disease characterized by an autoimmune-mediated destruction of small and medium-sized intrahepatic bile ducts. Originally PBC was considered to be rare and almost invariably fatal, mainly because the diagnosis was made in patients presenting with advanced symptomatic disease (jaundice and decompensated cirrhosis). However, the development of a reproducible indirect immunofluorescence assay for antimitochondrial antibody made it possible to diagnose the disease at an earlier stage, and introduction of ursodeoxycholic acid therapy as the first-line therapy for PBC drastically changed PBC-related mortality. At present, patients with an early histological stage have survival rates similar to those of an age- and sex-matched control population. Although 30% of patients treated with ursodeoxycholic acid may exhibit incomplete responses, obeticholic acid and drugs currently in development are expected to be effective for these patients and improve outcomes. Meanwhile, more etiology and immunopathology studies using new technologies and novel animal models are needed to dissect variances of clinical course, treatment response, and outcome in each patient with PBC. Precision medicine that is individualized for each patient on the basis of the cause identified is eagerly awaited.

Pharmacological interventions for primary biliary cholangitis: an attempted network meta-analysis

BACKGROUND

Primary biliary cholangitis (previously primary biliary cirrhosis) is a chronic liver disease caused by the destruction of small intra-hepatic bile ducts resulting in stasis of bile (cholestasis), liver fibrosis, and liver cirrhosis. The optimal pharmacological treatment of primary biliary cholangitis remains uncertain.

OBJECTIVES

To assess the comparative benefits and harms of different pharmacological interventions in the treatment of primary biliary cholangitis through a network meta-analysis and to generate rankings of the available pharmacological interventions according to their safety and efficacy. However, it was not possible to assess whether the potential effect modifiers were similar across different comparisons. Therefore, we did not perform the network meta-analysis, and instead, assessed the comparative benefits and harms of different interventions using standard Cochrane methodology.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and randomised controlled trials registers to February 2017 to identify randomised clinical trials on pharmacological interventions for primary biliary cholangitis.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) in participants with primary biliary cholangitis. We excluded trials which included participants who had previously undergone liver transplantation. We considered any of the various pharmacological interventions compared with each other or with placebo or no intervention.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We calculated the odds ratio (OR) and rate ratio with 95% confidence intervals (CI) using both fixed-effect and random-effects models based on available-participant analysis with Review Manager 5. We assessed risk of bias according to Cochrane, controlled risk of random errors with Trial Sequential Analysis, and assessed the quality of the evidence using GRADE.

MAIN RESULTS

We identified 74 trials including 5902 participants that met the inclusion criteria of this review. A total of 46 trials (4274 participants) provided information for one or more outcomes. All the trials were at high risk of bias in one or more domains. Overall, all the evidence was low or very low quality. The proportion of participants with symptoms varied from 19.9% to 100% in the trials that reported this information. The proportion of participants who were antimitochondrial antibody (AMA) positive ranged from 80.8% to 100% in the trials that reported this information. It appeared that most trials included participants who had not received previous treatments or included participants regardless of the previous treatments received. The follow-up in the trials ranged from 1 to 96 months.The proportion of people with mortality (maximal follow-up) was higher in the methotrexate group versus the no intervention group (OR 8.83, 95% CI 1.01 to 76.96; 60 participants; 1 trial; low quality evidence). The proportion of people with mortality (maximal follow-up) was lower in the azathioprine group versus the no intervention group (OR 0.56, 95% CI 0.32 to 0.98; 224 participants; 2 trials; I2 = 0%; low quality evidence). However, it has to be noted that a large proportion of participants (25%) was excluded from the trial that contributed most participants to this analysis and the results were not reliable. There was no evidence of a difference in any of the remaining comparisons. The proportion of people with serious adverse events was higher in the D-penicillamine versus no intervention group (OR 28.77, 95% CI 1.57 to 526.67; 52 participants; 1 trial; low quality evidence). The proportion of people with serious adverse events was higher in the obeticholic acid plus ursodeoxycholic acid (UDCA) group versus the UDCA group (OR 3.58, 95% CI 1.02 to 12.51; 216 participants; 1 trial; low quality evidence). There was no evidence of a difference in any of the remaining comparisons for serious adverse events (proportion) or serious adverse events (number of events). None of the trials reported health-related quality of life at any time point.

FUNDING

nine trials had no special funding or were funded by hospital or charities; 31 trials were funded by pharmaceutical companies; and 34 trials provided no information on source of funding.

AUTHORS' CONCLUSIONS

Based on very low quality evidence, there is currently no evidence that any intervention is beneficial for primary biliary cholangitis. However, the follow-up periods in the trials were short and there is significant uncertainty in this issue. Further well-designed randomised clinical trials are necessary. Future randomised clinical trials ought to be adequately powered; performed in people who are generally seen in the clinic rather than in highly selected participants; employ blinding; avoid post-randomisation dropouts or planned cross-overs; should have sufficient follow-up period (e.g. five or 10 years or more); and use clinically important outcomes such as mortality, health-related quality of life, cirrhosis, decompensated cirrhosis, and liver transplantation. Alternatively, very large groups of participants should be randomised to facilitate shorter trial duration.

Clinical Course and Genetic Susceptibility of Primary Biliary Cirrhosis: Analysis of a Prospective Cohort

BACKGROUND

Natural history of primary biliary cirrhosis (PBC) is partially characterized in patients from the Mediterranean area whose genetic background differs from that of Northern Europeans.

OBJECTIVES

We aimed to describe genetic susceptibility and clinical course of PBC in patients from Southern Italy.

METHODS

Socio-demographic, clinical, biochemical and histological data at diagnosis as well as disease progression of 81 PBC consecutive patients were collected. All subjects were treated with Ursodeoxycholic acid at a dose of 15 mg/kg. HLA class II DRB1 alleles were compared with those of 237 healthy control subjects. IL28B genotyping for IL28B rs12979860 C/T and rs80899917 G/T was performed in a sub-group of patients.

RESULTS

HLA-DRB1*07 (RR 5.3, P = 0.0008) and HLA-DRB1*08 (RR n.c. P = 0.0005) were significantly associated with the risk of PBC development. Patients younger than 45 years had significantly higher alanine aminotransferase (P = 0.038) and alkaline phosphatase levels (P = 0.047) than older cases. In comparison to non-CC rs12979860, patients with CC rs12979860 genotype showed an early histological stage at onset (93.8% vs. 62.5%, P = 0.03). After a mean follow-up of 61 months, three patients died, one underwent liver transplantation and sixteen (21.9%) had progression of the disease. At multivariate analysis, extrahepatic autoimmune disease (P = 0.04), pruritus (P = 0.008) and advanced histological stage (P < 0.0001) were independent risk factors for disease progression.

CONCLUSIONS

HLA-DRB1*07 and HLA-DRB1*08 alleles increase susceptibility to disease development. At onset, higher biochemical activity was observed in younger patients, whereas rs12979860 CC genotype was associated with milder histological stage. Pruritus and coexistence of extrahepatic autoimmune diseases were significantly associated with poorer prognosis.

Extrahepatic malignancies in primary biliary cirrhosis: a comparative study at two European centers

Limited information and divergent results are available on the prevalence/incidence, survival, and risk factors for developing extrahepatic malignancies (EMs) in primary biliary cirrhosis (PBC). The aim of the study was to analyze the epidemiology and survival rates for EM in PBC patients. The study was conducted on two series of patients followed up at two European centers (361 in Padova, Italy, and 397 in Barcelona, Spain) for a mean 7.7 ± 7 and 12.2 ± 7 years, respectively. The cancer incidence was compared with the standardized incidence ratios (SIRs) calculated using the Cancer Registry of the Veneto Region (Italy) and the Cancer Registry of Tarragona (Spain). Seventy-two patients developed EM. The prevalence of cases was similar in Padova (9.7 %) and Barcelona (9.4 %). The overall cancer incidence was similar to the expected incidence for the general population in the same geographical area (SIR = 1.2), and so was the crude EM rate (855.01 vs 652.86 per 100,000 patient-years, respectively, RR = 1.3). Logistic regression analysis showed that advanced histological stage and extrahepatic autoimmune diseases were significantly associated with the onset of EM. Survival was similar for PBC patients with and without EM (p = n.s.), and actual survival was similar to the one predicted by the Mayo model. The incidence of EM in PBC patients was found similar in Italy and Spain and no different from that of the general population. Advanced histological stage and extrahepatic autoimmune disease were risk factors significantly associated with EM developing in PBC. The onset of cancer in PBC patients does not influence the natural history of their liver disease.

Geoepidemiology and space-time analysis of Primary biliary cirrhosis in Crete, Greece

BACKGROUND & AIMS

The prevalence of Primary biliary cirrhosis varies in different geographical areas. This might reflect genetic or environmental risk factors. We aimed to define Primary biliary cirrhosis prevalence and incidence, describe patient's spatial distribution, generate prediction maps and detect any possible routing pattern of time-spatial appearance of the disease in Crete, Greece.

METHODS

From 1990-2010, 245 Primary biliary cirrhosis patients diagnosed and followed up at the Gastroenterology Department of the University Hospital and the District Hospitals of the island, were contacted and 222 were included in the time-spatial analysis. To map their spatial distribution per 5-year periods, geospatial models were applied in Gis-ArcMap 9.3 software. Kriging Interpolation methods were used to generate prediction maps for the disease in Crete. Areas of high and low probability of disease occurrence were estimated through multicriteria modelling. The disease route was defined by Gis-ArcMap's toolbox.

RESULTS

Prevalence was found to be 365 cases per million, with a mean incidence of 20.88 (range 3.79-35.99). Prediction map estimates from 1.22 to 11 patients per 50 km2 all over Crete. Areas of high risk of disease occurrence are located in the Eastern part, while low risk in the Western part of the island.

DISCUSSION

Prevalence and incidence of Primary biliary cirrhosis in Crete are among the higher published in Europe. Given the homogeneous and stable study population and the geopolitics of the island, the heterogeneity in the time-spatial distribution and the route of disease appearance strongly suggest a role for environmental causative agents.

The diagnosis of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic liver disease characterized by the immune mediated destruction of small intrahepatic bile duct epithelial cells leading to cholestasis and cirrhosis. The autoimmune basis of PBC is supported by the highly specific anti-mitochondrial antibodies (AMAs) and autoreactive T cells, the former being the basis for diagnosis in the vast majority of cases. Although a rare disease, the incidence rates of PBC have been increasing, possibly due to increased testing and diagnosis as opposed to a true increase in disease incidence. Presently, most cases are asymptomatic and only suspected based upon routine liver tests. Those with symptoms typically complain of pruritus and fatigue. The diagnosis of PBC is based on the presence of at least 2 of 3 key criteria including a persistently elevated serum alkaline phosphatase, the presence of serum AMAs, and liver histology consistent with PBC. Anti-nuclear antibodies specific to PBC are useful in cases in which AMAs are not detected and may indicate a more aggressive course. Ursodeoxycholic acid is the only proven therapy for PBC and in most cases can delay or prevent disease progression. However, a subgroup of patients does not adequately respond to ursodeoxycholic acid and for whom new therapies are needed.

Primary biliary cirrhosis in Southern Israel: a 20 year follow up study

BACKGROUND

The epidemiology of primary biliary cirrhosis (PBC) in Israel is unknown. We aimed to determine the epidemiology, long-term survival and outcomes of PBC in Southern Israel from 1990 to 2010.

METHODS

Case-finding methods and population-based administrative data were used to estimate and evaluate the incidence, prevalence and prognostic factors of outcome in our PBC cohort.

RESULTS

138 cases of PBC were identified. The average annual prevalence of PBC was 255 cases per million. The overall age/sex-adjusted annual incidence of PBC was 10 cases per million from 1990 through 1999 and 20 cases per million from 2000 to 2010. Among 138 incident cases with a total follow-up of 960 persons-years from diagnosis, 30 patients (21.7%) died. Survival in PBC patients was significantly lower than that of the age/sex-matched Israeli population. Mortality was significantly increased in patients with an initial MELD score greater than 8 (P<0.001), with portal hypertension (P<0.001), and in non-responders to ursodeoxycholic acid (UDCA) therapy according to Barcelona criteria (P=0.005). Out of 138 patients, 95 patients (68.0%) responded to UDCA therapy according to Barcelona and Paris criteria. None of the responders died during the follow-up period as opposed to 30 out of 43 (69.8%) of non-responders. In multivariate analysis the factors associated with response to UDCA were: albumin levels above 3.5 g/dL (P<0.001) and lower degree of fibrosis per liver biopsy (P=0.003).

CONCLUSIONS

This study addresses the increasing burden of PBC in Israel and confirms the importance of some clinical and therapeutic factors as predictors of long-term prognosis.

The epidemiology and natural history of primary biliary cirrhosis: a nationwide population-based study

BACKGROUND AND AIMS

Very few population-based studies exist on the epidemiology of primary biliary cirrhosis (PBC), and none have been conducted in the last decade. We aimed to determine the epidemiology and prognosis of PBC over the past two decades.

METHODS

Patients were identified by multiple case finding strategies, covering the total population of Iceland. A search was conducted in the centralized database of antimitochondrial antibody (AMA) measurements and computerized diagnosis and pathological registries. All AMA measurements taken in Iceland between 1991 and 2010 were analyzed. Relevant clinical information was gathered from medical records, pathology reports, and death certificates. Incidence was compared between two periods, 1991-2000 versus 2001-2010.

RESULTS

A total of 168 patients were identified, of which 138 were female (82%), with a median age 62 years (range 13-92). Prevalence at the end of the study period was 38.3 cases per 100 000 person-years. Age-standardized incidence for female patients during the first period was 3.4 versus 4.1 during the second (NS) and that for male patients was 0.6 during the first period versus 1.0 per 100 000 during the second (NS). Overall incidence in the first period was 2.0 and that in the second was 2.5 per 100 000 (NS). Stage III-IV liver fibrosis was present in 28% of patients at diagnosis with no significant differences between the two decades. Median survival after diagnosis was 15 years. Five patients underwent liver transplantation.

CONCLUSION

The incidence and prevalence figures of PBC in Iceland are among the highest reported and have been stable over the last two decades. The prognosis of patients in this population-based cohort is better than that previously reported.

Epidemiology of primary sclerosing cholangitis and primary biliary cirrhosis: a systematic review

OBJECTIVE

Studies on the epidemiology of primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC) show variable outcome. We aimed at systematically reviewing the incidence and prevalence rates, as well as geographical distribution and temporal trends of PSC and PBC.

DATA SOURCES

A systematic search of literature was performed in Medline and EMBASE (search last conducted January 10th, 2011).

STUDY SELECTION

Population-based epidemiological studies reporting incidence and/or prevalence rates for PSC or PBC in a defined geographical area of at least 100,000 adult inhabitants were considered relevant.

DATA EXTRACTION

Study area, study period, number of patients, number of inhabitants, incidence per 100,000 inhabitants per year, prevalence per 100,000 inhabitants, method of case-finding, method of case-ascertainment, male/female ratio and in case of PSC, occurrence of inflammatory bowel diseases (IBD) were extracted from retrieved articles.

RESULTS

The literature search yielded 2286 abstracts of which 31 articles fulfilled all inclusion criteria. Studies varied in size from 10 to 770 patients in catchment areas from 100,312 to 19,230,000 inhabitants. The incidence and prevalence rates for PSC range from 0 to 1.3 per 100,000 inhabitants/year and 0-16.2 per 100,000 inhabitants, respectively. PBC incidence rates range from 0.33 to 5.8 per 100,000 inhabitants/year and prevalence rates range from 1.91 to 40.2 per 100,000 inhabitants; prevalence rates are increasing in time.

CONCLUSIONS

Incidence and prevalence rates of both PSC and PBC vary widely and seem to be increasing. True population-based studies are scarce and therefore large population-based studies combining meticulous case-finding and case-ascertainment strategies are necessary.

Updated assessment of the prevalence, spectrum and case definition of autoimmune disease

Autoimmune diseases are heterogeneous with regard to prevalence, manifestations, and pathogenesis. The classification of autoimmune diseases has varied over time. Here, we have compiled a comprehensive up-to-date list of the autoimmune diseases, and have reviewed published literature to estimate their prevalence. We identified 81 autoimmune diseases. The overall estimated prevalence is 4.5%, with 2.7% for males and 6.4% for females. For specific diseases, prevalence ranges from 1% to <1/10(6). Considering all diseases in the class, the most common mean age-of-onset was 40-50 years. This list of autoimmune diseases has also yielded information about autoantigens. Forty-five autoimmune diseases have been associated with well-defined autoantigens. Of the diseases with known autoantigens, 33.3% had highly repetitive sequences, 35.6% had coiled-coil arrangements and 57.8% were associated with cellular membranes, which means that based on these structural motifs alone, autoantigens do not appear to be a random sample of the human proteome. Finally, we identified 19 autoimmune diseases that phenocopy diseases arising from germline mutations in the corresponding autoantigen. Collectively, our findings lead to a tentative proposal for criteria for assigning autoimmune pathogenesis to a particular disease.

Primary biliary cirrhosis and Sjögren's syndrome: autoimmune epithelitis

Primary biliary cirrhosis (PBC) has been often coined a model autoimmune disease based on the homogeneity amongst patients, the frequency and similarity of antimitochondrial antibodies, including the highly directed immune response to pyruvate dehydrogenase (PDC-E2). A significant number of patients with PBC suffer from sicca and amongst these, there are patients who also have classic Sjögren's syndrome. Indeed, both PBC and Sjögren's syndrome are characterized by inflammation of target epithelial elements. Both diseases can be considered on the basis of a number of other related clinical aspects, including proposed unique apoptotic features of the target tissue, the role of secretory IgA, and the frequency with which both diseases overlap with each other. Indeed, PBC may be considered a Sjögren's syndrome of the liver, whereas Sjögren's syndrome can be equally discussed as PBC of the salivary glands. Dissection of the genetic predispositions for both diseases and especially the molecular basis of effector mechanisms, will become critical elements in developing new therapies.

Diagnosis of primary biliary cirrhosis

Primary biliary cirrhosis is the archetypal autoimmune liver disease, with the disease label describing a chronic granulomatous lymphocytic small bile duct cholangitis, which now most commonly presents asymptomatically and at an early pre-cirrhotic stage. Disease is more common than thought, with 1 in 1000 women over the age of 40 affected. Characteristic immunologic features of the disease assist clinicians in ready non-invasive diagnosis of patients, even if asymptomatic with only anicteric/cholestatic liver biochemical profiles. Over 90% of patients are anti-mitochondrial antibody positive, and for those negative, a significant proportion have highly specific anti-nuclear antibody profiles. Liver biopsy remains useful in certain settings where clarity is needed to confirm diagnosis, exclude alternative disease, and assess the relative contribution of PBC to other co-existent liver injury, and seeks to demonstrate in particular the classic bile duct lesions, as well as the degree of interface activity.

Update on the epidemiology of primary biliary cirrhosis

The epidemiology of primary biliary cirrhosis was described as early as the 1970s, yet decades later the true frequency of this disease and its associated risk factors are still in question. There has been a wealth of data documenting the various incidence and prevalence rates across the world, demonstrating potential risk factors inherent to geographic differences. Studies that follow primary biliary cirrhosis in a set population over time have offered the most reliable picture of disease frequency. Analysis of clustering effects through region and time has offered valuable information on the complexity of the disease development. Improved epidemiologic surveillance of primary biliary cirrhosis around the world will be necessary to provide definitive evidence on the phenomenon of clustering and its associations with proposed risk factors in the literature.

Primary biliary cirrhosis

Primary biliary cirrhosis is a chronic liver disease characterised by intrahepatic bile-duct destruction, cholestasis, and, in some cases, cirrhosis. Evidence supporting the autoimmune nature of this disorder includes the appearance of highly specific antimitochondrial antibodies (AMAs) and autoreactive T cells. Concordance rates in monozygotic twins, familial prevalence, and genetic associations underscore the importance of genetic factors, whereas findings of epidemiological studies and murine models suggest a possible role for exogenous chemicals and infectious agents through molecular mimicry. The incidence of primary biliary cirrhosis has increased over recent decades, possibly attributable to augmented testing of liver biochemistry rather than a rise in disease incidence. AMAs remain the hallmark of diagnosis in most cases and allow detection of asymptomatic patients. Symptomatic individuals usually present with either pruritus or fatigue and, more rarely, with either jaundice or complications of cirrhosis. The prognosis of primary biliary cirrhosis has improved because of early diagnosis and use of ursodeoxycholic acid, the only established medical treatment for this disorder. Although not a cure, treatment can slow disease progression and delay the need for liver transplantation. However, some patients do not respond adequately to ursodeoxycholic acid and might need alternative therapeutic approaches.

Baseline ductopenia and treatment response predict long-term histological progression in primary biliary cirrhosis

OBJECTIVES

Laboratory and pathological predictors of future histological progression in primary biliary cirrhosis (PBC) are needed for routine practice and clinical trials. We sought to develop clinically meaningful markers for those with predominantly early disease at risk of progressive liver damage.

METHODS

Patients with PBC (n=69) with a follow-up liver biopsy performed approximately 10 years after initial histological diagnosis were identified and reviewed.

RESULTS

Histological progression in the stage of fibrosis observed in paired liver biopsies from the same patient was associated with the absence of biochemical response to ursodeoxycholic acid (UDCA) at 2 years: alkaline phosphatase (ALP) >1.67 × ULN (upper limit of normal) (P=0.001, odds ratio (OR) 12.14, 95% confidence interval (CI) 2.69-54.74) when defined as an increase in one stage and ALP > 1.76 × ULN (P=0.03, OR 5.07, 95% CI 1.17-21.95) when defined as an increase in two stages. Ductopenia (>50% loss), as formally evaluated through blinded biopsy review of liver tissue obtained at initial diagnosis in a subset of 34 patients, predicted histological progression (P=0.012), along with biochemical response to UDCA (P=0.002). The presence of interface hepatitis in the same biopsies did not.

CONCLUSIONS

Patients with PBC who fail to show a biochemical response to UDCA or who have ductopenia on baseline biopsy progress histologically during extended follow-up. Such patients may benefit from novel treatments, with our exploratory data providing a means of identifying these individuals early in their disease.

Prevalence of primary biliary cirrhosis in adults referring hospital for annual health check-up in Southern China

BACKGROUND

Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterized by the presence of anti-mitocondrial autoantibodies (AMA) which has an essential role also for diagnosis. In addition, also some anti-nuclear antibodies (ANA) have been shown to be highly specific PBC. The purpose of this study was to assess the prevalence of PBC among the adults referring hospital for annual health check-up in Southern China by screening sera for PBC-specific autoantibodies.

METHODS

AMA and ANA were screened in 8,126 adults (mean age 44 ± 15 years, 48% females) by indirect immunofluorenscence (IIF). Positive sera were tested by ELISA/immunoblotting for AMA-M2, anti-sp100 and anti-gp210. A diagnosis of PBC was re-assessed six months after the initial testing.

RESULTS

Out of 8,126 individuals 35 were positive for AMA and 79 positive for ANA. Nineteen, 4, and 3 of the subjects positive for AMA and/or ANA showed reactivity for AMA-M2, anti-sp100 or gp210, respectively, further tested with ELISA/immunoblotting. Fourteen in the 39 individuals positive for AMA at IIF, AMA-M2, anti-gp210, or anti-sp100 had abnormal cholestatic liver functional indices. One definite and 3 probable PBC diagnosis could be made in 4 cases including 3 females and 1 male after half a year.

CONCLUSIONS

We found a point prevalence rate of PBC among Southern Chinese adults attending for yearly health check-up of 492 cases per million (95% CI, 128 to 1,093) and 1,558 cases per million (95% CI, 294 to 3,815) for women over 40, a finding similar to prevalence reported in other geographical areas.

Environmental factors and the induction of autoimmunity in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic disease with an autoimmune pathogenesis and an unknown etiology, predominantly affecting postmenopausal women. The term PBC is a misnomer since most cases currently diagnosed have limited probability to develop cirrhosis. Antimitochondrial autoantibodies, elevated IgM and selective destruction of the intrahepatic bile ducts are the hallmarks of PBC. A permissive genetic background is critical in producing susceptibility despite limited associations with alleles within the MHC. The disease has incomplete concordance in monozygotic twins and its geoepidemiology suggests a role for environmental factors in the induction of PBC. This hypothesis is further supported by clinical (risk factors) and experimental evidence. Some of the factors incriminated model molecular mimicry by infectious agents and xenobiotic chemicals. Additional candidates are being proposed through large screening; all proposed associations ultimately require confirmation in animal models and clinical practice.

Recent insights in the epidemiology of autoimmune diseases: improved prevalence estimates and understanding of clustering of diseases

Previous studies have estimated a prevalence of a broad grouping of autoimmune diseases of 3.2%, based on literature review of studies published between 1965 and 1995, and 5.3%, based on national hospitalization registry data in Denmark. We examine more recent studies pertaining to the prevalence of 29 autoimmune diseases, and use these data to correct for the underascertainment of some diseases in the hospitalization registry data. This analysis results in an estimated prevalence of 7.6-9.4%, depending on the size of the correction factor used. The rates for most diseases for which data are available from many geographic regions span overlapping ranges. We also review studies of the co-occurrence of diseases within individuals and within families, focusing on specific pairs of diseases to better distinguish patterns that may result in insights pertaining to shared etiological pathways. Overall, data support a tendency for autoimmune diseases to co-occur at greater than expected rates within proband patients and their families, but this does not appear to be a uniform phenomenon across all diseases. Multiple sclerosis and rheumatoid arthritis is one disease pair that appears to have a decreased chance of coexistence.

New insights into autoimmune liver diseases

Autoinflammatory liver disease represents an important aspect of global hepatological practice. The three principal disease divisions recognized are autoimmune hepatitis, primary sclerosing cholangitis and primary biliary cirrhosis. Largely, but not exclusively, these diseases are considered to be autoimmune in origin. Increased recognition of outlier and overlap syndromes, changes in presentation and natural history, as well as the increased awareness of IgG4-associated sclerosing cholangitis, all highlight the limitations of the classic terminology. New insights continue to improve the care given to patients, and have arisen from carefully conducted clinical studies, therapeutic trials, as well as genetic and laboratory investigations. The challenges remain to treat patients before liver injury becomes permanent and to prevent the development of organ failure.

Clinical features and management of primary biliary cirrhosis

Primary biliary cirrhosis (PBC), which is characterized by progressive destruction of intrahepatic bile ducts, is not a rare disease since both prevalence and incidence are increasing during the last years mainly due to the improvement of case finding strategies. The prognosis of the disease has improved due to both the recognition of earlier and indolent cases, and to the wide use of ursodeoxycholic acid (UDCA). New indicators of prognosis are available that will be useful especially for the growing number of patients with less severe disease. Most patients are asymptomatic at presentation. Pruritus may represent the most distressing symptom and, when UDCA is ineffective, cholestyramine represents the mainstay of treatment. Complications of long-standing cholestasis may be clinically relevant only in very advanced stages. Available data on the effects of UDCA on clinically relevant end points clearly indicate that the drug is able to slow but not to halt the progression of the disease while, in advanced stages, the only therapeutic option remains liver transplantation.

Primary biliary cirrhosis: the future

Primary biliary cirrhosis is a progressive cholestatic liver disease of presumed autoimmune etiology. Patterns of disease are changing with earlier recognition and better access to investigation and treatment. With the convergence of animal, genetic, and clinical studies over the coming years, it is hoped that a greater understanding in the pathophysiology of the disease will translate into improved clinical endpoints for patients.

Presentation and diagnosis of primary biliary cirrhosis in the 21st century

Primary biliary cirrhosis is a slowly progressive, cholestatic, and chronic liver disease in which the epithelium of the intrahepatic biliary tree is destroyed by a chronic inflammatory process. The origin of this disease, which mainly affects middle-aged women, is unknown but has characteristics favoring an autoimmune etiology. This article reviews the presentation and diagnosis of PBC in the 21st century.