Natural history of primary biliary cirrhosis

Gut Microbiome and Bile Acid Interactions: Mechanistic Implications for Cholangiocarcinoma Development, Immune Resistance, and Therapy

Cholangiocarcinoma (CCA) is a rare but highly malignant carcinoma of bile duct epithelial cells with a poor prognosis. The major risk factors of CCA carcinogenesis and progression are cholestatic liver diseases. The key feature of primary sclerosing cholangitis and primary biliary cholangitis is chronic cholestasis. It indicates a slowdown of hepatocyte secretion of biliary lipids and metabolites into bile as well as a slowdown of enterohepatic circulation (bile acid recirculation) of bile acids with dysbiosis of the gut microbiome. This leads to enterohepatic recirculation and an increase of toxic secondary bile acids. Alterations of serum and liver bile acid compositions via the disturbed enterohepatic circulation of bile acids and the disturbance of the gut microbiome then activate a series of hepatic and cancer cell signaling pathways that promote CCA carcinogenesis and progression. This review focuses on the mechanistic roles of bile acids and the gut microbiome in the pathogenesis and progression of CCA. It also evaluates the therapeutic potential of targeting the gut microbiome and bile acid-mediated signaling pathways for the therapy and prophylaxis of CCA.

On a deterministic mathematical model which efficiently predicts the protective effect of a plant extract mixture in cirrhotic rats

In this work, we propose a mathematical model that describes liver evolution and concentrations of alanine aminotransferase and aspartate aminotransferase in a group of rats damaged with carbon tetrachloride. Carbon tetrachloride was employed to induce cirrhosis. A second groups damaged with carbon tetrachloride was exposed simultaneously a plant extract as hepatoprotective agent. The model reproduces the data obtained in the experiment reported in [Rev. Cub. Plant. Med. 22(1), 2017], and predicts that using the plants extract helps to get a better natural recovery after the treatment. Computer simulations show that the extract reduces the damage velocity but does not avoid it entirely. The present paper is the first report in the literature in which a mathematical model reliably predicts the protective effect of a plant extract mixture in rats with cirrhosis disease. The results reported in this manuscript could be used in the future to help in fighting cirrhotic conditions in humans, though more experimental and mathematical work is required in that case.

Efficacy of ursodeoxycholic acid for primary biliary cholangitis: Experience from a tertiary care centre in Saudi Arabia

Background

Primary biliary cholangitis (PBC) is a progressive autoimmune cholestatic liver disease that primarily affects females more than males and may lead to end-stage liver disease. We studied baseline characteristics, and the biochemical and clinical response to ursodeoxycholic acid (UDCA), a first-line treatment option for patients with PBC, in a cohort of patients diagnosed with PBC from Saudi Arabia.

Methods

A total of 30 patients meeting the diagnostic criteria of PBC who were being followed in the King Faisal Specialist Hospital and Research Centre in Riyadh, Saudi Arabia, between January 1, 2008, and December 31, 2017, were enrolled in the study. The patients with autoimmune hepatitis, primary sclerosing cholangitis, and overlap syndromes were excluded. The baseline characteristics of the patients were recorded. The response to UDCA treatment was assessed according to the Barcelona, Paris I, Paris II, and Toronto criteria, and clinical outcomes, and biochemical changes were ascertained.

Results

The mean age was 46 years ± 11.7 with a female gender predominance of 93% (n = 28). Pruritus was the predominant symptom reported by 90% (n = 27) of the patients. A total of 23 (77.7%) patients underwent liver biopsy and all of them showed histological features suggestive of PBC. Cirrhosis was documented in 30% (n = 9) of the patients at baseline. Overall, 86.7% (n = 26) of the patients were positive for antimitochondrial antibodies. The biochemical response rates to UDCA based on Paris I, Paris II, Barcelona, and Toronto criteria were 73.3, 40, 56.7, and 53.3%, respectively.

Conclusion

Over 10 years, 30 patients with PBC were diagnosed at a large referral center in Saudi Arabia. The response to UDCA treatment was inadequate.

Bezafibrate therapy in primary biliary cholangitis refractory to ursodeoxycholic acid: a longitudinal study of paired liver biopsies at 5 years of follow up

BACKGROUND

Ursodeoxycholic acid (UDCA) is the first-line therapy for primary biliary cholangitis (PBC). However, nearly 40% of patients have an incomplete response to UDCA. The addition of bezafibrate has shown biochemical benefit in this group of patients.

AIM

To evaluate the long-term effects of UDCA in combination with bezafibrate on histological outcomes in patients with UDCA-refractory PBC.

METHODS

Fifty-nine patients refractory to UDCA were included. Clinical parameters were monitored and paired liver biopsy (PLB) was performed after 5 years of follow-up.

RESULTS

Of the total cohort, 49 subjects were analysed and 31 had PLB at 5 years. Values for serum ALP, AST, ALT and GGT significantly improved with UDCA-bezafibrate. This beneficial effect was observed at 12 months where 86% achieved ALP at normal levels. Analyses of PLB showed a significant decrease in liver damage as reflected by Ludwig (baseline 2.29 ± 1.2, to 1.84 ± 1 at year 5, P = 0.0242) and Ishak (baseline 6.19 ± 2.2 to 4.77 ± 2.2 at year 5, P = 0.0008) scores. Overall, regression of fibrosis was attained in 48% of patients. Furthermore, we observed a significant reduction in the proportion with cirrhosis from 19% at baseline to 3% at 5 years (P < 0.001). These beneficial effects were associated with better predictive risk scores using the GLOBE and UK-PBC prognosis models.

CONCLUSIONS

Adding bezafibrate to UDCA in patients with UDCA-refractory PBC showed a significant decrease in fibrosis and inflammatory histological scores at 5 years. These beneficial effects warrant further evaluation in long-term cohort studies and controlled trials.

Autoimmunity affecting the biliary tract fuels the immunosurveillance of cholangiocarcinoma

Cholangiocarcinoma (CCA) results from the malignant transformation of cholangiocytes. Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are chronic diseases in which cholangiocytes are primarily damaged. Although PSC is an inflammatory condition predisposing to CCA, CCA is almost never found in the autoimmune context of PBC. Here, we hypothesized that PBC might favor CCA immunosurveillance. In preclinical murine models of cholangitis challenged with syngeneic CCA, PBC (but not PSC) reduced the frequency of CCA development and delayed tumor growth kinetics. This PBC-related effect appeared specific to CCA as it was not observed against other cancers, including hepatocellular carcinoma. The protective effect of PBC was relying on type 1 and type 2 T cell responses and, to a lesser extent, on B cells. Single-cell TCR/RNA sequencing revealed the existence of TCR clonotypes shared between the liver and CCA tumor of a PBC host. Altogether, these results evidence a mechanistic overlapping between autoimmunity and cancer immunosurveillance in the biliary tract.

Anxiety and Depression in Patients with Primary Biliary Cholangitis: Current Insights and Impact on Quality of Life

Primary biliary cholangitis (PBC), formerly known as primary biliary cirrhosis, is a chronic cholestatic immune-mediated liver disease characterized by injury to intrahepatic bile ducts that may ultimately progress to cirrhosis and liver failure and result in the need for liver transplant or death without treatment. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) are approved therapies for PBC and are associated with a reduced risk of progression of disease, although patients may continue to experience significant symptoms of pruritus and fatigue independent of liver disease. The two most commonly reported symptoms among patients with PBC are fatigue and pruritus which may be debilitating, and negatively impact physical, mental, emotional, and social wellbeing. Intense symptom burden has been associated with depressive symptoms, cognitive defects, poor sleep schedules, and social isolation. This literature review explores the presence of anxiety and depressive symptoms in chronic liver disease, the impact of symptom burden on patients' wellbeing, and available pharmaceutical and natural therapies.

Systematic Influence of Circulating Bilirubin Levels on Osteoporosis

Observational studies report some association between circulating bilirubin levels and osteoporosis, but it is unknown if this association is causal or confounded. In this two-sample Mendelian randomization (MR) study, we included a large genome-wide association study (GWAS) associated with total bilirubin levels among 317,639 people, a large meta-analysis to identify genetic variants associated with bone mineral density (BMD) estimated by heel quantitative ultrasound (eBMD) among 426,824 individuals and fracture among 1.2 million individuals. The results revealed that circulating bilirubin levels had no causal influence on eBMD (beta-estimate: 0.004, 95% confidence interval [CI]: -0.019 to 0.028, SE:0.012, P-value=0.705) or the risk of fracture (beta-estimate: -0.009, 95% CI: -0.035 to 0.017, SE:0.013, P-value=0.488), which were both confirmed by multiple sensitivity analyses. Our results confirm that circulating bilirubin levels have no causal role in eBMD or the incidence of fracture, indicating that circulating bilirubin levels is unlikely to be a causal risk factor for osteoporosis or fracture.

3,5-Diethoxycarbonyl-1,4-Dihydrocollidine Diet: A Rodent Model in Cholestasis Research

Liver cholestasis is characterized by impairment in bile flow. Among cholestatic diseases, primary biliary cholangitis and primary sclerosing cholangitis represent relevant causes of chronic liver disease, associated to significant morbidity and mortality. To better understand and to address therapeutic strategies to cholangiopathies is essential to develop an in vivo model which recapitulates the pathological features of the disease. Chronic feeding of 3,5-diethoxycarbonyl-1,4-dihydrocollidine, named DDC, has been proposed as an in vivo model for cholestatic disease due to the formation of intraductal porphyrin plugs. Chronic feeding of DDC in mice reproduces the main histopathological hallmarks of human cholestatic disease such as (1) remodeling of biliary compartments giving rise to ductular reaction, (2) periductular fibrosis, and (3) inflammatory infiltrate. This chapter describes the materials and methods necessary for the development and characterization of DDC diet-based mouse model.

Primary biliary cholangitis

Primary cholangitis (cirrhosis) is a chronic cholestatic disease with an unquestionable female predominance. It is characterised by inflammation of the small and medium size bile ducts, and can eventually progress to cirrhosis. Most patients remain asymptomatic and are diagnosed by the casual finding of an anicteric biochemical cholestasis with increased alkaline phosphatase. The pathogenesis is unknown and of presumed autoimmune origin in genetic susceptible subjects. M2-type antimitochondrial antibodies, and specific antinuclear antibodies (gp210 and Sp100) are typical and specific of the disease. The positivity of these antibodies and a biochemical cholestasis are sufficient for diagnosis, without the need for liver biopsy. Ursodeoxycholic acid is the specific treatment with an excellent response in more than 60% of patients. When this optimal response is not observed, it can be combined with new agents, but those that have shown to be effective are those that improve cholestasis such as fibrates and obeticholic acid.

Primary biliary cholangitis and bone disease

Osteoporosis, characterized by compromised bone strength leading to fragility fractures, is a common event in patients with primary biliary cholangitis (PBC). Osteomalacia, defined by poor bone mineralization is very uncommon. The pathogenesis of osteoporosis is not well clarified, but it mainly results from low bone formation. Few reports have revealed increased bone resorption, particularly in end-stage disease. The prevalence of osteoporosis is about 35% in the most significant studies, and it depends on the diagnostic criteria and severity of liver damage. Osteoporosis is associated with age, postmenopausal status, duration of PBC and advanced histological stage. Bone densitometry is the common method for the diagnosis of osteoporosis and should be performed in all patients with PBC. Lateral X-rays of the dorsal and lumbar spine should also be carried out to disclose vertebral fractures. There is no specific treatment but bisphosphonates, especially alendronate and ibandronate, efficiently increases bone mass and prevents bone loss. Despite these positive effects on bone mass no clear results on decreasing the fracture rate have been demonstrated, probably because the low number of patients included in the trials. The potential value of new agents requires further evaluation.

Symptoms of PBC - Pathophysiology and management

Primary biliary cholangitis is a chronic cholestatic liver disease characterised by progressive bile duct damage and, ultimately, biliary cirrhosis. Though up to fifty percent of the patients can be asymptomatic at presentation, symptoms when present are frequently debilitating with significant impact on quality of life and functional status. Characteristic symptoms include pruritus, fatigue and an increasingly recognised mild cognitive impairment. With the exception of pruritus, the "classic" cholestatic symptom, therapeutic options to treat PBC related symptoms are currently limited leaving patients with often significant residual problems. Symptoms can frequently contribute to depression and social isolation further compounding the quality of life impairment. There is need to better understand the current therapeutic options available in order to optimise their use, and to explore newer avenues to understand the pathophysiology of the symptom-generating processed in PBC in order to develop new therapies.

External validation of the United Kingdom-primary biliary cholangitis risk scores of patients with primary biliary cholangitis treated with ursodeoxycholic acid

The United Kingdom-Primary Biliary Cholangitis (UK-PBC) risk scores are a set of prognostic models that estimate the risk of end-stage liver disease in patients with PBC at 5-, 10- and 15-year intervals. They have not been externally validated outside the United Kingdom. In this retrospective, external validation study, data were abstracted from outpatient charts and discrimination and calibration of the UK-PBC risk scores were assessed. A total of 464 patients with PBC treated with ursodeoxycholic acid were included. The median diagnosis age was 52.4 years, and 88% were female patients. The cumulative incidence of events was 6%, 9%, and 15% at 5, 10, and 15 years, respectively. Concordance (c-statistic) was 0.88, 0.85, and 0.84 using the 5-, 10- and 15-year risk scores, respectively, which was slightly lower than values observed in the United Kingdom validation cohort. Using the 5-year risk score, more events were observed than predicted (25 versus 16.8; P = 0.046); using the 10-year risk score, there was no difference between the observed and predicted number of events (35 versus 44.9; P = 0.14); conversely, using the 15-year risk score, fewer events were observed than predicted (46 versus 67.5; P = 0.009). Limiting evaluation by the 15-year UK-PBC risk score to those with >10 years of follow-up demonstrated no difference between observed and predicted events. Using the 5-year risk score, patients within the highest quartile had statistically significant worse event-free survival compared to the rest of the cohort: 82% versus 98% at 5 years, 73% versus 97% at 10 years, and 58% versus 93% at 15 years. Conclusion: In patients assessed at a North American tertiary medical center, the UK-PBC risk score had excellent discrimination and was reasonably calibrated both in the short and long term. (Hepatology Communications 2018;2:676-682).

Novel strategies and therapeutic options for the management of primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease. It has a varied course of progression ranging from being completely asymptomatic to aggressive disease leading to cirrhosis and resulting in liver transplantation. In addition, symptoms can be debilitating and can have a major impact on quality of life. For decades, there was only one anti-cholestatic agent available to target this disease and that was only effective in around half of patients, with little or no effect on symptoms. With increasing understanding of the pathogenic mechanisms of PBC and potential targets for drug treatment, pharmaceutical companies have shown a greater interest in this rare disease. A large number of novel therapeutic molecules have been developed and are currently being evaluated. In this review article all the novel molecules in use and in trials targeting cholestasis and symptoms in PBC are discussed.

The management of autoimmunity in patients with cholestatic liver diseases

Cholestatic liver diseases are rare diseases that often lead to cirrhosis and its consequent complications. In addition to liver-related morbidity, patients with cholestatic liver diseases often suffer from autoimmune diseases that affect several organs and tissues. The robust and efficient data collection and collaboration between hepatologists and rheumatologists have led to significant advancements in understanding the relationship between the cholestatic liver diseases and associated autoimmune diseases. In this paper, we discuss the cholestatic liver diseases (primary biliary cirrhosis, primary sclerosing cholangitis and immunoglobulin G4 associated cholangitis) and associated autoimmune diseases.

Autotaxin, Pruritus and Primary Biliary Cholangitis (PBC)

Autotaxin (ATX) is a 125-kD type II ectonucleotide pyrophosphatase/phosphodiesterase (ENPP2 or NPP2) originally discovered as an unknown "autocrine motility factor" in human melanoma cells. In addition to its pyrophosphatase/phosphodiesterase activities ATX has lysophospholipase D (lysoPLD) activity, catalyzing the conversion of lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA). ATX is the only ENPP family member with lysoPLD activity and it produces most of the LPA in circulation. In support of this, ATX heterozygous mice have 50% of normal LPA plasma levels. The ATX-LPA signaling axis plays an important role in both normal physiology and disease pathogenesis and recently has been linked to pruritus in chronic cholestatic liver diseases, including primary biliary cholangitis (PBC). Several lines of evidence have suggested that a circulating puritogen is responsible, but the identification of the molecule has yet to be definitively identified. In contrast, plasma ATX activity is strongly associated with pruritus in PBC, suggesting a targetable molecule for treatment. We review herein the biochemistry of ATX and the rationale for its role in pruritus.

Risk of cerebrovascular accident in patients with primary biliary cirrhosis: a systematic review and meta-analysis

OBJECTIVE

Dyslipidemia is common among patients with primary biliary cirrhosis (PBC) and might increase the risk of cerebrovascular accident (CVA). However, data from epidemiologic studies remain inconclusive. This study aims to further investigate this association.

MATERIALS AND METHODS

We carried out a systematic review and meta-analysis of observational studies that compared the risk of CVA in patients with PBC versus controls. Pooled risk ratios and 95% confidence intervals were combined using a random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Four studies with 2309 patients with PBC were identified and included in our data analysis. The pooled risk ratio of CVA in patients with PBC was 1.11 (95% confidence interval, 0.81-1.51). The statistical heterogeneity was insignificant, with an I of 14%.

CONCLUSION

A significantly increased risk of CVA among patients with PBC was not observed in this study.

Coronary artery disease in primary biliary cirrhosis: A systematic review and meta-analysis of observational studies

AIM

To investigate the association between primary biliary cirrhosis (PBC) and risk of coronary artery disease (CAD).

METHODS

We conducted a systematic review and meta-analysis of published observational studies that reported relative risks, odd ratios, hazard ratios or standardized incidence ratios with 95% confidence intervals (CI) comparing CAD risk in patients with PBC versus non-PBC controls. Pooled risk ratios and 95% confidence intervals were combined using a random-effect model and generic inverse variance of DerSimonian and Laird methods.

RESULT

Four studies with 3362 patients with PBC were identified and included in our data analysis. The pooled risk ratio of CAD in patients with PBC was 1.57 (95% CI, 1.21-2.06). The statistical heterogeneity was low with an I(2) of 38%.

CONCLUSION

Our study demonstrated a statistically significant increased risk of CAD among patients with PBC.

Primary biliary cirrhosis: Clinical and laboratory criteria for its diagnosis

Primary biliary cirrhosis (PBC) is a chronic progressive cholestatic granulomatous, and destructive inflammatory lesion of small intralobular and septal bile ducts, which is likely to be caused by an autoimmune mechanism with a the presence of serum antimitochondrial antibodies and a potential tendency to progress to cirrhosis. Despite the fact that the etiology of this disease has been unknown so far, there has been a considerable body of scientific evidence that can reveal the clinical and laboratory signs of PBC and the individual components of its pathogenesis and elaborate diagnostic criteria for the disease and its symptomatic therapy. Deficiencies in autoimmune tolerance are critical factors for the initiation and perpetuation of the disease. The purpose of this review is to summarize the data available in the literature and the author's findings on clinical and laboratory criteria for the diagnosis of PBC. This review describes the major clinical manifestations of the disease and the mechanisms of its development. It presents the immunological, biochemical, and morphological signs of PBC and their significance for its diagnosis. A great deal of novel scientific evidence for the problem of PBC has been accumulated. However, the inadequate efficiency of therapy for the disease lends impetus to the quest for its etiological factors and to further investigations of its pathogenetic mechanisms and, on this basis, to searches for new methods for its early diagnosis.

Effects of total bilirubin on the prevalence of osteoporosis in postmenopausal women without potential liver disease

It is still uncertain whether total bilirubin per se is a risk factor for osteoporosis in postmenopausal women and no study has so far examined this important issue. This study was designed to assess the sheer effects of total bilirubin on the prevalence of osteoporosis in postmenopausal women without potential liver disease. In the present study, postmenopausal female subjects without potential liver disease (n = 918) who underwent measurement of bone mineral density were enrolled. Correlation and logistic regression analysis were used to assess the relationship between total bilirubin and other variables. As a result, subjects with osteoporosis had a significantly lower total bilirubin level (P = 0.005). A 0.1 mg/dl increase in total bilirubin was associated with reduced odds ratio of the risk by 38 % for osteoporosis [OR 0.62 (95 % CI 0.52-0.88), P = 0.012] after adjustment for several variables. Total bilirubin was independently associated with BMD [coefficient = 0.41, 95 % CI (0.35-0.47), P < 0.001 for lumbar spine and coefficient = 0.44, 95 % CI (0.36-0.48), P < 0.001 for femur neck]. A positive correlation could be observed with significant difference between total bilirubin and z-score (r = 0.33, P < 0.001 for lumbar spine and r = 0.37, P < 0.001 for femur neck) and total bilirubin was positively correlated with serum calcium (r = 0.13, P < 0.001) as well. Therefore, this study demonstrates an independent inverse association between total bilirubin and the prevalence of osteoporosis in postmenopausal women without potential liver disease. Total bilirubin would be useful as a provisional new risk factor of osteoporosis in such a population.

Prognostic indicators in primary biliary cirrhosis: significance of revised IAHG (International Autoimmune Hepatitis Group) score

Background/Aims

Primary biliary cirrhosis (PBC) is a slowly progressing autoimmune disease of the liver that is characterized by portal inflammation and immune-mediated destruction of the intrahepatic bile ducts. Serum total bilirubin is one of the various prognostic factors that have been proposed. A recent study found that PBC with accompanying autoimmune hepatitis (AIH) carries a negative prognosis. This study examined the clinical characteristics of PBC and analyzed the factors that affect its prognosis.

Methods

Patients diagnosed with PBC between January 1998 and December 2010 based on clinical and histopathological findings were compiled and analyzed retrospectively.

Results

Among 27 patients, 24 (1 male and 23 females, ages 50.0±9.3 years) were followed up. The follow-up period was 8.6±0.9 years. Of the 24 patients, 9 patients progressed to liver cirrhosis (LC). Comparison between patients who did and did not progress to LC revealed statistically significant differences in the patients' serum total bilirubin (2.7±1.8 vs. 0.8±0.4, P=0.012), the Mayo risk score (5.1±0.7 vs. 3.9±0.6, P=0.001), the revised IAHG (International Autoimmune Hepatitis Group) score (9.2±2.3 vs. 5.4±3.0, P=0.004) and frequency of AIH overlap (5/9 [55.6%] vs. 0/15 [0%], P=0.001) at the time of diagnosis.

Conclusions

We propose that serum total bilirubin, the Mayo risk score, and the revised IAHG score at the time of diagnosis are helpful for predicting PBC prognosis. In particular, since all of the patients with accompanying AIH progressed to LC, the presence of overlap syndrome at the time of diagnosis is helpful for predicting PBC prognosis and providing an adequate treatment.

Clinical features of primary biliary cirrhosis: An analysis of 114 cases

AIM: To summarize the clinical characteristics of primary biliary cirrhosis (PBC) and to explore the clinical significance of serum anti-mitochondrial antibodies (AMAs) in the diagnosis and assessment of severity of PBC.

METHODS: A retrospective analysis of clinical manifestations, serum biochemical parameters, serum antibodies and pathological features was performed in 114 patients with PBC. M2 antibody-positive patients (105 cases) were divided into four groups: those positive for only M2 (61 cases), for both M2 and M9 (9 cases), for both M2 and M4 (25 cases), and for M2, M4, and M9 (10 cases). Serological markers and complications were compared among the four groups.

RESULTS: Main clinical manifestations of PBC include fatigue, jaundice, and skin itching. The levels of alkalinity phosphatase (ALP), γ-glutamyl transpeptidase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) increased to varying degrees. Serum AMA and M2 antibodies had a very high specificity and sensitivity in diagnosing PBC. Compared to the M2-positive group, the levels of ALP and IgM in M2-M4-positive group were higher (P = 0.010, 0.014, P < 0.05). Compared to the M2-M9-positive group, the levels of AST, TBIL, and IgG in the M2-M4-M9 positive group were higher (P = 0.039, 0.016, 0.039, P < 0.05). Compared to the M2-positive group, the level of TBIL in the M2-M4-M9 positive group was higher (P = 0.023, P < 0.05). Compared to the M2-M9 positive group, the level of IgG in the M2-positive group was higher (P = 0.031, P < 0.05). Thus, serum M4 and M9 levels have clinical significance in the diagnosis of PBC.

CONCLUSION: Understanding the clinical characteristics of PBC can help improve the diagnosis, treatment, and prognosis of this disease.

Primary biliary cirrhosis and liver transplantation

Primary biliary cirrhosis (PBC) is an immune-mediated chronic progressive inflammatory liver disease, predominantly affecting middle-aged women, characterized by the presence of antimitochondrial antibodies (AMAs), which can lead to liver failure. Genetic contributions, environmental factors including chemical and infectious xenobiotics, autoimmunity and loss of tolerance have been aggressively investigated in the pathogenesis of PBC, however, the actual impact of these factors is still controversial. Survival of PBC patients has been largely improved with the widespread use of ursodeoxycholic acid (UDCA), however, one third of patients still do not respond to the treatment and proceed to liver cirrhosis, requiring liver transplantation as a last resort for cure. The outcome of liver transplantation is excellent with 5- and 10-year survival rates around 80% and 70%, respectively, while along with long survival, the recurrence of the disease has become an important outcome after liver transplantation. Prevalence rates of recurrent PBC rage widely between 1% and 35%, and seem to increase with longer follow-up. Center-specific issues, especially the use of protocol biopsy, affect the variety of incidence, yet, recurrence itself does not affect patient and graft survival at present, and retransplantation due to recurrent disease is extremely rare. With a longer follow-up, recurrent disease could have an impact on patient and graft survival.

The diagnosis and treatment of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a slowly progressive cholestatic liver disease of autoimmune etiology. The initial presentation of PBC is various from asymptomatic, abnormal liver biochemical tests to overt cirrhosis. The diagnosis of PBC is based on cholestatic biochemical liver tests, presence of antimitochondrial antibody and histologic findings of nonsuppurative destructive cholangitis. Although the diagnosis is straightforward, it could be underdiagnosed because of its asymptomatic presentation, or underrecognition of the disease. UDCA in a dose of 13-15 mg/kg is the widely approved therapy which can improve the prognosis of patients with PBC. However, one-third of patients does not respond to UDCA therapy and may require liver transplantation. Every effort to diagnose PBC in earlier stage and to develop new therapeutic drugs and clinical trials should be made.

Recent insights into the relationship between inflammatory liver diseases and atherosclerosis

Atherosclerosis is a dynamic process in the human body. Many studies have evaluated atherosclerosis and its relationship with other systems in the body. Our perception of its pathogenesis is evolving with the introduction of new players in the game. It is no longer possible to consider the atherosclerosis as an independent process, unaffected by the liver and its function. Although several tasks performed by the liver, such as lipid metabolism, have been implicated in the pathogenesis of atherosclerosis, the role of other disorders of the liver (autoimmune diseases, viral hepatitis, and cirrhosis) are not fully understood. In this review, the most commonly encountered inflammatory liver diseases and their effects on atherosclerosis are discussed.

Immune-mediated bile duct injury: The case of primary biliary cirrhosis

Autoimmune cholangitis would be the appropriate name to define the immune-mediated bile duct injury following the breakdown of tolerance to mitochondrial proteins and the appearance of serum autoantibodies and autoreactive T cells. Nevertheless, the condition is universally named primary biliary cirrhosis (PBC). The disease etiology and pathogenesis remain largely unknown despite the proposed lines of evidence. One twin study and numerous epidemiology reports suggest that both a susceptible genetic background and environmental factors determine disease onset while a recent genome-wide association study proposed highly significant associations with several common genetic polymorphisms in subgroups of patients. Specific infectious agents and chemicals may contribute to the disease onset and perpetuation in a genetically susceptible host, possibly through molecular mimicry. Importantly, several murine models have been proposed and include strains in which PBC is genetically determined or induced by immunization with chemicals and bacteria. From a pathogenetic standpoint, new exciting data have demonstrated the unique apoptotic features of bile duct cells that allow the mitochondrial autoantigens to be taken up in their intact form within apoptotic blebs. We are convinced that the application of the most recent molecular techniques will soon provide developments in PBC etiology and pathogenesis with likely implications in diagnostics and therapeutics.

Fatigue in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic, autoimmune, cholestatic liver disease with a slowly progressive course. Without treatment, most patients eventually develop fibrosis of the liver and may need liver transplantation in the late stage of disease. Fatigue and pruritus are the most common symptoms of PBC, but the majority of patients are asymptomatic at first presentation. There is no specific treatment for fatigue in PBC, but modafinil has shown some potential beneficial effects, such as increased energy levels and decreased total sleep time. This Review article discusses the natural history and the measurement of fatigue in patients with PBC. The central and the peripheral mechanisms that have been suggested for the pathogenesis of fatigue in PBC are also discussed and treatment options are reviewed.

Experimental evidence on the immunopathogenesis of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease for which an autoimmune pathogenesis is supported by clinical and experimental data, including the presence of autoantibodies and autoreactive T cells. The etiology remains to be determined, yet data suggest that both a susceptible genetic background and unknown environmental factors determine disease onset. Multiple infectious and chemical candidates have been proposed to trigger the disease in a genetically susceptible host, mostly by molecular mimicry. Most recently, several murine models have been reported, including genetically determined models as well as models induced by immunization with xenobiotics and bacteria.

Primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an immune-mediated chronic cholestatic liver disease with a slowly progressive course. Without treatment, most patients eventually develop fibrosis and cirrhosis of the liver and may need liver transplantation in the late stage of disease. PBC primarily affects women (female preponderance 9–10:1) with a prevalence of up to 1 in 1,000 women over 40 years of age. Common symptoms of the disease are fatigue and pruritus, but most patients are asymptomatic at first presentation. The diagnosis is based on sustained elevation of serum markers of cholestasis, i.e., alkaline phosphatase and gamma-glutamyl transferase, and the presence of serum antimitochondrial antibodies directed against the E2 subunit of the pyruvate dehydrogenase complex. Histologically, PBC is characterized by florid bile duct lesions with damage to biliary epithelial cells, an often dense portal inflammatory infiltrate and progressive loss of small intrahepatic bile ducts. Although the insight into pathogenetic aspects of PBC has grown enormously during the recent decade and numerous genetic, environmental, and infectious factors have been disclosed which may contribute to the development of PBC, the precise pathogenesis remains enigmatic. Ursodeoxycholic acid (UDCA) is currently the only FDA-approved medical treatment for PBC. When administered at adequate doses of 13–15 mg/kg/day, up to two out of three patients with PBC may have a normal life expectancy without additional therapeutic measures. The mode of action of UDCA is still under discussion, but stimulation of impaired hepatocellular and cholangiocellular secretion, detoxification of bile, and antiapoptotic effects may represent key mechanisms. One out of three patients does not adequately respond to UDCA therapy and may need additional medical therapy and/or liver transplantation. This review summarizes current knowledge on the clinical, diagnostic, pathogenetic, and therapeutic aspects of PBC.

Clinical and pathological features of primary biliary cirrhotic patients with negative anti-mitochondria antibody M2 subtype

AIM: To explore the clinical and pathological features of primary biliary cirrhotic (PBC) patients with negative anti-mitochondria antibody M₂ subtype (AMA-M₂).

METHODS: Fifty six PBC cases from the second affiliated hospital of Kunming Medical College between AD 2000 and 2007 were selected. The clinical data (general status, laboratory findings) and pathologic data were reviewed in 22 cases of negative AMA-M₂ antibody. And the clinical data of the negative AMA-M₂ anti-body cases were compared with the positive ones.

RESULTS: The general status and laboratory findings (biochemical data, immune function) of AMA-M₂ antibody negative were compared with the positive ones, with no significant difference observed (all P > 0.05). Remarkable changes in bile ducts, especially in small bile ducts were observed in 22 negative AMA-M₂ antibody cases. Those changes were related to staging. Inflammatory cells, mainly lymphocytes were seen around the bile duct. Remarkable infiltrated inflammatory cells, mainly lymphocytes, even lymphoid follicles were observed in the portal area. Liver cells changed mildly and were non-specific. The changes of different stages existed and intermixed in one sample.

CONCLUSION: Liver biopsy is useful to confirm to diagnosis of PBC with negative M₂ antibody and an important criteria for staging determination.

Advances in antifibrotic therapy

Sustained progress in defining the molecular pathophysiology of hepatic fibrosis has led to a comprehensive framework for developing antifibrotic therapies. Indeed, the single greatest limitation in bringing new drugs to the clinical setting is a lack of clarity regarding clinical trial and treatment end points, not a lack of promising agents. A range of treatments, including those developed for other indications, as well as those specifically developed for hepatic fibrosis, are nearing or in clinical trials. Most are focused on attacking features of either hepatic injury and/or activated stellate cells and myofibroblasts, which are the primary sources of extracellular matrix (scar) proteins. Thus, features of injury and stellate cell activation provide a useful template for classifying these emerging agents and point to a new class of therapies for patients with fibrosing liver disease.

Plasma adiponectin levels in primary biliary cirrhosis: a novel perspective for link between hypercholesterolemia and protection against atherosclerosis

INTRODUCTION

Hypercholesterolemia is a common finding in primary biliary cirrhosis (PBC), but the risk of cardiovascular events in PBC patients is not increased in respect to the general population. High serum adiponectin levels appear to play a protective role in the development of either metabolic syndrome or cardiovascular disease.

AIM

To investigate factors potentially preventing atherosclerosis in PBC patients.

METHODS

Circulating levels of adiponectin, resistin, leptin, and tumor necrosis factor-alpha (TNF-alpha) were measured in 137 consecutive PBC patients (125 women, 12 men; mean age 61.6 +/- 12.3 yr), 137 sex- and age-matched healthy controls, and 30 female patients with nonalcoholic steatohepatitis (NASH) and associated metabolic syndrome.

RESULTS

The body mass index (BMI) was comparable in the three groups, whereas total cholesterol was significantly higher in both PBC and NASH cases than in controls (221.6 +/- 50.5 mg/dL in PBC vs 221.7 +/- 39.7 mg/dL in NASH vs 209.8 +/- 39.2 mg/dL in controls, P < 0.05). Serum concentrations of adiponectin, resistin, and leptin were significantly higher in PBC patients than in either NASH cases or controls (P < 0.05). Among the PBC patients, only adiponectin correlated positively with histological progression of the disease (P= 0.001) and negatively with BMI (P= 0.01). Logistic regression analysis revealed that adiponectin correlated independently with age, BMI, Mayo score, and gamma-glutamyl transpeptidase.

CONCLUSIONS

The high adiponectin concentrations observed in PBC patients should be regarded as a possible protective factor against atherogenesis. The search for further protective factors should be encouraged.

Hepatic fibrosis -- overview

The study of hepatic fibrosis, or scarring in response to chronic liver injury, has witnessed tremendous progress in the past two decades. Clarification of the cellular sources of scar, and emergence of hepatic stellate cells not only as a fibrogenic cell type, but also as a critical immunomodulatory and homeostatic regulator are among the most salient advances. Activation of hepatic stellate cells remains a central event in fibrosis, complemented by evidence of additional sources of matrix-producing cells including bone marrow, portal fibroblasts, and epithelial-mesenchymal transition from both hepatocytes and cholangiocytes. A growing range of cytokines and their receptors and inflammatory cell subsets have further expanded our knowledge about this dynamic process. Collectively, these findings have laid the foundation for continued elucidation of underlying mechanisms, and more importantly for the implementation of rationally based approaches to limit fibrosis, accelerate repair and enhance liver regeneration in patients with chronic liver disease.

Natural history of primary biliary cirrhosis

The natural history of primary biliary cirrhosis (PBC) has improved significantly over the last two decades. Most patients are diagnosed with asymptomatic PBC (a-PBC). The prognosis of a-PBC is usually better than that of symptomatic PBC (s-PBC). Among a-PBC patients, some remain asymptomatic, whereas others progress to s-PBC. The prognosis of s-PBC is still poor and the main cause of death in PBC is liver failure. Other complications, such as esophageal varices and hepatocellular carcinoma, also affect the prognosis of PBC patients. Ursodeoxycholic acid treatment improves the prognosis of PBC patients in the early stage. There seems to be several types of PBC progression.

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 is not an additional risk factor for bone loss in women receiving regular calcium and vitamin D supplementation: a controlled longitudinal study

BACKGROUND AND GOALS

Alterations in bone metabolism in primary biliary cirrhosis (PBC) are generally considered to be highly prevalent and severe, but no data are available from prospective studies with adequate control groups. The aims of this study were: (1) to measure changes in bone mineral density (BMD) over time; (2) to correlate the degree of bone loss with the severity of liver disease; and (3) to characterize bone disease in PBC patients receiving regular calcium and vitamin D supplementation.

STUDY

We enrolled 118 women with PBC (mean age+/-SD: 56+/-11 y; 72% postmenopausal; 43% with cirrhosis), and measured BMD (lumbar spine, DXA-Hologic) at entry and serially over the following 5 years. The controls were 472 healthy women selected from a large observational group matched for age and menopausal status (mean age+/-SD: 55+/-10 y; 73% postmenopausal).

RESULTS

Mean BMD was 0.851+/-0.142 g/cm2 in the PBC group and 0.857+/-0.158 g/cm2 in the control group; the prevalence of osteoporosis was 28% and 29%, respectively. BMD significantly correlated with age and postmenopausal status, but not with liver cirrhosis or serum bilirubin levels. The biochemical markers of bone turnover were high in about 50% of the patients. The yearly bone loss in the PBC group was 0.008 g/cm2 (95% confidence interval: 0.014-0.003) similar to that calculated in the control group.

CONCLUSIONS

Among patients with PBC, the prevalence of osteoporosis and the yearly rate of BMD loss are similar to those observed in the general population, and are not associated with the severity of liver disease.

Autoimmune liver disease 2007

Autoimmune liver disease (ALD) includes a spectrum of diseases which comprises both cholestatic and hepatitic forms: autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and the so called "overlap" syndromes where hepatitic and cholestatic damage coexists. All these diseases are characterized by an extremely high heterogeneity of presentation, varying from asymptomatic, acute (as in a subset of AIH) or chronic (with aspecific symptoms such as fatigue and myalgia in AIH or fatigue and pruritus in PBC and PSC). The detection and characterization of non organ specific autoantibodies plays a major role in the diagnostic approach of autoimmune liver disease; anti nuclear reactivities (ANA) and anti smooth muscle antibodies (SMA) mark type 1 AIH, liver kidney microsomal antibody type 1 (LKM1) and liver cytosol type 1 (LC1) are the serological markers of type 2 AIH; antimitochondrial antibodies (AMA) are associated with PBC, while no specific marker is found in PSC, since anticytoplasmic neutrophil antibodies with perinuclear pattern (atypical p-ANCA or p-ANNA) are also detected in a substantial proportion of type 1 AIH cases. Treatment options rely on immunosoppressive therapy (steroids and azathioprine) in AIH and on ursodeoxycholic acid in cholestatic conditions; in all these diseases liver transplantation remains the only therapeutical approach for the end stage of liver disease.

Risk factors for intrahepatic and extrahepatic cholangiocarcinoma in the United States: a population-based case-control study

BACKGROUND & AIMS

Intrahepatic and extrahepatic cholangiocarcinomas are rare and highly malignant cancers of the bile duct. Although the incidence of extrahepatic cholangiocarcinoma (ECC) has remained constant, the incidence of intrahepatic cholangiocarcinoma (ICC) has increased in the United States. Because the etiology of both tumors is poorly understood, a population-based case-control study was conducted to examine the association of ECC and ICC with preexisting medical conditions.

METHODS

Medical conditions among 535 ICC patients, 549 ECC patients (diagnosed 1993-1999), and 102,782 cancer-free controls were identified by using the Surveillance, Epidemiology and End Results-Medicare databases. Logistic regression analysis was used to calculate adjusted odds ratios.

RESULTS

In addition to established risk factors (choledochal cysts, cholangitis, inflammatory bowel disease), several other conditions were significantly associated with ECC and ICC: biliary cirrhosis (ECC, ICC: P < .001), cholelithiasis (ECC, ICC: P < .001), alcoholic liver disease (ECC, P < .001; ICC, P = .01), nonspecific cirrhosis (ECC, ICC: P < .001), diabetes (ECC, ICC: P < .001), thyrotoxicosis (ECC, P = .006; ICC, P = .04), and chronic pancreatitis (ECC, ICC: P < .001). Conditions only associated with ICC were obesity (ECC, P = .71; ICC, P = .01), chronic nonalcoholic liver disease (ECC, P = .08; ICC, P = .02), HCV infection (ECC, P = .67; ICC, P = .01), and smoking (ECC, P = .07; ICC, P = .04).

CONCLUSIONS

Several novel associations with ECC and ICC were identified. HCV infection, chronic nonalcoholic liver disease, and obesity, all of which are increasing in incidence, and smoking were associated only with ICC, suggesting that these conditions might explain the divergent incidence trends of the tumors.

Clinical epidemiology of primary biliary cirrhosis: incidence, prevalence, and impact of therapy

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease of unknown etiology. It is typically characterized by a trio of criteria including cholestatic liver biochemistry tests for at least 6 month's duration, the presence of a positive serum antimitochondrial antibody, and histologic findings from liver biopsy that are compatible or diagnostic with PBC. Although no unifying mechanism of action has been described to explain the pathogenesis of PBC to date, the natural history of this condition is greatly influenced by several known and unknown risk factors. In turn, a number of publications have focused on describing the burden of disease and prognosis in patients with PBC, This review article will summarize the descriptive epidemiology of PBC including new insights on risk factors, prognosis, and the effect of medical therapy in contemporary patients.

Primary biliary cirrhosis, hyperlipidemia, and atherosclerotic risk: a systematic review

Primary Biliary Cirrhosis (PBC) is a chronic, progressive liver disease associated with markedly elevated serum lipids, but it is not clear if PBC is associated with accelerated atherosclerosis. The present systematic review examined the relationship of PBC to atherosclerotic risk. The lipid abnormalities in PBC are complex, depend on the stage of hepatic dysfunction and affect most lipoprotein classes. Increased cholesterol levels in PBC are primarily due to LP-X, an abnormal LDL particle. LP-X has anti-atherogenic properties and may reduce the atherosclerotic risk. Few studies have examined coronary artery disease (CAD) events in PBC, and none have sufficient sample size of follow-up to determine CAD risk in PBC patients. Nevertheless, one study suggested that 12% of PBC patients died from circulatory system diseases suggesting that lipid treatment is appropriate in some patients. Additional larger scale, prospective studies are required to determine the necessity of lipid treatment in this patient group. In the interim, decisions on the use of lipid lowering agents depend largely on the prognosis of the PBC and physician and patient preference for treatment.

Concept on the pathogenesis and treatment of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an organ-specific autoimmune disease that predominantly affects women and is characterized by chronic, progressive destruction of small intrahepatic bile ducts with portal inflammation and ultimately fibrosis, leading to liver failure in the absence of treatment. Little is known about the etiology of PBC. PBC is characterized by anti-mitochondrial antibodies and destruction of intra-hepatic bile ducts. The serologic hallmark of PBC is the presence of auto-antibodies to mitochondria, especially to the E2 component of the pyruvate dehydrogenase complex (PDC). Current theories on the pathogenesis of PBC favor the hypothesis that the disease develops as a result of an inappropriate immune response following stimulation by an environmental or infectious agent. Some reports suggest that xenobiotics and viral infections may induce PBC. The pathogenetic mechanism is believed to be caused by a defect in immunologic tolerance, resulting in the activation and expansion of self-antigen specific T and B lymphocyte clones and the production of circulating autoantibodies in addition to a myriad of cytokines and other inflammatory mediators. This leads to ductulopenia and persistent cholestasis, by developing end-stage hepatic-cell failure. In this review are given our own and literary data about mechanisms of development of intrahepatic cholestasis and possible ways of its correction.

Primary biliary cirrhosis: solving the enigma

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease, most commonly affecting female patients between 40 and 60 years of age. Patient sera present autoantibodies against mitochondrial antigens (AMA) and elevated serum IgM. Histologic studies demonstrate progressive destruction of small- and medium-sized intrahepatic bile ducts and, ultimately, liver cirrhosis. The precise mechanisms leading to selective destruction of such biliary epithelial cells are still unknown, although a number of immunomediated pathways have been proposed. Genetic background is critical in determining susceptibility to the disease, although no clear association with haplotypes of the major histocompatibility complex has been identified. Molecular mimicry by either infectious agents or xenobiotics has been proposed as a means of breaking tolerance in genetically predisposed individuals, thus leading to the onset of PBC. In this review, available data and current theories regarding the immunomediated pathogenesis of PBC will be described.

Mitochondrial antigens as targets of cellular and humoral auto-immunity in primary biliary cirrhosis

Several factors point toward an auto-immune pathogenesis for primary biliary cirrhosis(PBC), mostly based on the presence of serum auto-antibodies to mitochondrial antigens(AMAs) and autoreactive T cells (both helper and cytotoxic). Interestingly, epitopes recognized by AMA and T-cell clones are located within overlapping areas of the antigens. Moreover,a role for an imbalance in cytokine pattern and for natural-killer lymphocytes has also been proposed. Despite several experimental reports, no clear evidence is available regarding the interaction of these factors leading to bile duct destruction. This article reviews the current reports regarding the auto-immune reaction against mitochondrial auto-antigens in PBC.

Hyperbilirubinemia is not a major contributing factor to altered bone mineral density in patients with chronic liver disease

Reduced bone density is commonly encountered in patients with chronic liver disease. Prior studies have shown that unconjugated bilirubin inhibits osteoblast activity and function in vitro and in animal models of bone mineralization. To determine whether hyperbilirubinemia promotes the development of hepatic osteodystrophy, bone mineral density (BMD) was measured by dual energy X-ray absorptiometry in a cohort of 86 consecutive patients with chronic liver disease referred for liver transplant evaluation. The mean age of the study population was 52 years (range, 22-73), in which 52% were female and 90% were white. Average bone density values were significantly lower than expected for age, race, and sex, with Z-scores for the femoral neck and spine of -0.50 (95% confidence interval [CI] -0.63 to -0.37; p=0.0003) and -0.69 (95% CI -0.85 to -0.52; p=0.0001), respectively. Sixty-one subjects (71%) exhibited reduced BMD (T-score of femoral neck or spine<or=-1 standard deviation [SD] below the young-adult mean), and 18 subjects (21%) met criteria for osteoporosis (T-score<-2.5 SD). Stepwise logistic regression analyses identified significant associations between BMD and serum creatinine, alkaline phosphatase, age, and gender. On the other hand, neither unconjugated, nor conjugated, nor total serum bilirubin levels were found to predict diminished BMD. The lack of association between serum unconjugated bilirubin levels and bone mineralization was validated in hyperbilirubinemic Gunn rats, in which BMD and serum osteocalcin levels were no different than in wild-type rodents. In conclusion, the finding that serum bilirubin levels do not correlate with reduced BMD in patients with end-stage liver disease, and that chronic unconjugated hyperbilirubinemia does not lead to alterations in bone mineralization in Gunn rats, suggests that bilirubin is not a major contributing factor to hepatic osteodystrophy.

Risk factors and comorbidities in primary biliary cirrhosis: a controlled interview-based study of 1032 patients

Primary biliary cirrhosis (PBC) is an autoimmune disease of unknown etiology, often associated with other autoimmune conditions. Controlled studies have so far provided conflicting data on risk factors and comorbidity rates in PBC. We enrolled patients with PBC (n = 1032) from 23 tertiary referral centers for liver diseases in the United States and random-digit-dialed controls (n = 1041) matched for sex, age, race, and geographical location. Patients and controls were administered a modified version of the US National Health and Nutrition Examination Study (NHANES III) questionnaire by trained personnel to evaluate associations between PBC and social, demographic, personal and family medical histories, lifestyle, and reproductive factors and the rates of comorbidity in affected individuals. Data indicate that having a first-degree relative with PBC (adjusted odds ratio [AOR] 10.736; 95% confidence interval 4.227-27.268), history of urinary tract infections (AOR 1.511, 95% CI 1.192-1.915), past smoking (AOR 1.569, 95% CI 1.292-1.905), or use of hormone replacement therapies (AOR 1.548, 95% CI 1.273-1.882) were significantly associated with increased risk of PBC. The frequent use of nail polish slightly increased the risk of having PBC. Other autoimmune diseases were found in 32% of cases and 13% of controls (P<0.0001). In conclusion, environmental factors, possibly including infectious agents through urinary tract infections or chemicals contained in cigarette smoke, may induce PBC in genetically susceptible individuals. Exogenous estrogens may also contribute to explain the female predominance of the disease.