Primary biliary cirrhosis: past, present, and future

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.

Chlorambucil for patients with primary biliary cirrhosis

BACKGROUND

Chlorambucil has been used for patients with primary biliary cirrhosis as it possesses immunosuppressive properties. But it is unknown whether it benefits or harms these patients.

OBJECTIVES

To evaluate the beneficial and any harmful effects of chlorambucil for primary biliary cirrhosis patients.

SEARCH METHODS

Eligible trials were identified by searching the Cochrane Hepato-Biliary Group Controlled Trials Register (March 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2012, Issue 2), MEDLINE (1946 to March 2012), EMBASE (1974 to March 2012), Science Citation Index EXPANDED (1900 to March 2012), The Chinese Biomedical Database (1976 to March 2012), The Chinese Medical Current Contents (1994 to March 2012), The China Hospital Knowledge Database (1994 to March 2012), and a database of ongoing trials (http://www.controlled-trials.com/mrct/) (accessed 6 March 2012). The reference lists of the retrieved publications and review articles were also read through, and pharmaceutical companies known to produce chlorambucil were contacted.

SELECTION CRITERIA

Randomised clinical trials, irrespective of language, year of publication, and publication status, comparing chlorambucil at any dose versus placebo, no intervention, another active drug, or one dose of chlorambucil with another dose.

DATA COLLECTION AND ANALYSIS

We planned to assess continuous data with mean differences (MD), and dichotomous outcomes with relative risk (RR), both with 95% confidence intervals (CI). As we only identified one trial, Fisher's exact tests were employed.

MAIN RESULTS

Only one randomised trial was identified and included in the review. The bias risk in the trial was high. The trial compared chlorambucil versus no intervention in 24 patients with primary biliary cirrhosis. Fisher's exact test did not show a significant reduction of mortality when comparing chlorambucil with no treatment (0/13 (0%) versus (2/11 (18.2%); P = 0.20). There was no significant difference regarding adverse events for chlorambucil compared with no treatment, but all patients receiving chlorambucil experienced adverse events (13/13 (100%) versus (3/11 (27%); P = 0.1). According to the authors of the trial, chlorambucil led to a significant improvement in mean serum levels of bilirubin (P < 0.05), albumin (P < 0.05), immunoglobulin M (P < 0.01), serum aspartate aminotransferase activity (P < 0.01), and hepatic inflammatory infiltrates (P < 0.01).

AUTHORS' CONCLUSIONS

There is not sufficient evidence to support or reject the use of chlorambucil for patients with primary biliary cirrhosis. Chlorambucil may show benefit in some unvalidated surrogate outcome measures (for example, serum bilirubin and immunoglobulin M levels). Chlorambucil is, however, connected with a number of adverse events. Bone marrow suppression should be noted in particular. Further randomised clinical trials are necessary to assess the benefits and harms of chlorambucil in this indication.

Application of a new histological staging and grading system for primary biliary cirrhosis to liver biopsy specimens: Interobserver agreement

Recently the authors proposed a new staging and grading system for primary biliary cirrhosis (PBC) that takes into account necroinflammatory activity and histological heterogeneity. Herein is proposed a convenient version of this system. Scores for fibrosis, bile duct loss, and chronic cholestasis were combined for staging: stage 1, total score of 0; stage 2, score 1-3; stage 3, score 4-6; and stage 4, score 7-9. Cholangitis activity (CA) and hepatitis activity (HA) were graded as CA0-3, and HA0-3, respectively. Analysis of interobserver agreement was then conducted. Digital images of 62 needle liver biopsy specimens of PBC were recorded as virtual slides on DVDs that were sent to 28 pathologists, including five located overseas. All participants were able to apply this version in all 62 cases. For staging, kappa was 0.385 (fair agreement) and the concordance rate was 63.9%. For necroinflammatory activity, the kappa and concordance rate were 0.110 (slight agreement) and 36.9% for CA, and 0.197 (slight agreement) and 47% for HA, respectively. In conclusion, this new staging and grading system for PBC seems to be more convenient and practical than those used at present, but more instruction and guidance are recommended for the grading of necroinflammatory activity in practice.

Biochemical markers for non-invasive assessment of disease stage in patients with primary biliary cirrhosis

AIM: To evaluate different biochemical markers and their ratios in the assessment of primary biliary cirrhosis (PBC) stages.

METHODS: This study included 112 patients with PBC who underwent a complete clinical investigation. We analyzed the correlation (Spearman's test) between ten biochemical markers and their ratios with different stages of PBC. The discriminative values were compared using areas under receiver operating characteristic (ROC) curves.

RESULTS: The mean age of patients included in the study was 53.88 ± 10.59 years, including 104 females and 8 males. We found a statistically significant correlation between PBC stage and Aspartate aminotransferase (AST), Alanine aminotransferase (ALT) to platelet ratio (APRI), ALT/platelet count, AST/ALT, ALT/AST and ALT/Cholesterol ratios, with the values of Spearman’s rho of 0.338, 0.476, 0.404, 0.356, 0.351 and 0.325, respectively. The best sensitivity and specificity was shown for AST/ALT, with an area under ROC of 0.660.

CONCLUSION: Biochemical markers and their ratios do correlate with different sensitivity to and specificity of PBC disease stage. The use of biochemical markers and their ratios in clinical evaluation of PBC patients may reduce, but not eliminate, the need for liver biopsy.

CD56 as a useful marker in the regenerative process of the histological progression of primary biliary cirrhosis

OBJECTIVE

Owing to recent contradicting results in the study of the regenerative process after hepatic injury in primary biliary cirrhosis, we investigated the use of CD56 in tissue repair during the histological progression of primary biliary cirrhosis.

METHODS

Fifty-three specimens were classified into Ludwig's stages (1-4) as follows: 14 specimens as stage 1, 23 as stage 2, 14 as stage 3, and two as stage 4. Immunohistochemical stain was performed for CD56. The cell types expressing the marker were morphologically analyzed to determine their origin.

RESULTS

In normal liver biliary epithelial cells (including the epithelium of terminal bile ducts and bile ductules), hepatocytes, and intermediate cells (features between hepatocytes and biliary cells, distributed in interface between hepatic parenchyma and portal tract) were CD56. In primary biliary cirrhosis specimens, biliary epithelial cells, hepatocytes, and intermediate cells were CD56 distributed as 10 out of 14 cases as stage 1 (71.43%), 18 out of 23 as stage 2 (78.26%), nine out of 14 as stage 3 (64.28%), and two out of two as stage 4 (100%). The total positive cases were 39 of 53 (73.58%). CD56 was expressed equally in all three types of cells.

CONCLUSION

These findings indicate that the consistent and uniform expression of CD56 in biliary epithelial cells, hepatocytes, and intermediate cells during hepatic injury in primary biliary cirrhosis is probably related to cellular damage and may be important in tissue regeneration. Furthermore, we cannot distinguish a specific cell type from the three above mentioned ones (biliary epithelial cells, hepatocytes, intermediate cells) as a putative stem cell in primary biliary cirrhosis.

Demonstration of PDC-E1 subunits as major antigens in the complement-fixing fraction M4 and re-evaluation of PDC-E1-specific antibodies in PBC patients

BACKGROUND

Primary biliary cirrhosis (PBC) is characterized by the presence of antimitochondrial antibodies (AMA). Autoantibodies specific for the mitochondrial M4 antigen can be detected by a complement fixation test (CFT) but not by immunoblotting. The aim of this study was to elucidate the identity of the M4 antigen.

PATIENTS AND METHODS

M4 proteins were purified by affinity chromatography using IgG fractions of PBC marker sera being CFT positive (n=5) or negative (n=5) and identified by Western blotting, silver staining and sequence analysis. Further, a cohort of 57 PBC patients was tested for the reactivity to M4 and pyruvate dehydrogenase complex (PDC).

RESULTS

Two AMA patterns of the marker sera were visualized: CFT-positive sera were defined as PDC-E2(+)/E1(+) and the CFT-negative sera as PDC-E2(+)/E1(-). The major proteins in the M4 fraction could be related to the PDC-E1 subunits. A clear-cut association between anti-M4 reactivity in the CFT and the reactivity to both PDC subunits could also be documented in the cohort of 57 PBC patients showing anti-PDC-E1alpha and E1beta antibodies at a frequency of 74% and 67%.

CONCLUSIONS

CFT reactivity against M4 antigens could be preferentially identified as a reaction against PDC-E1. As PDC-E1 subunits as compared with PDC-E2 lack lipoyl-binding sites, they probably have to be considered as an independent and important target.

Upregulation of a basolateral FXR-dependent bile acid efflux transporter OSTalpha-OSTbeta in cholestasis in humans and rodents

Organic solute transporter (OSTalpha-OSTbeta) is a novel heteromeric bile acid and sterol transporter expressed at the basolateral membranes of epithelium in the ileum, kidney, and liver. To determine whether OSTalpha-OSTbeta undergoes farnesoid X receptor (FXR)-dependent adaptive regulation following cholestatic liver injury, mRNA and protein expression levels were analyzed in patients with primary biliary cirrhosis (PBC) and following common bile duct ligation (CBDL) in rats and Fxr null and wild-type mice. Hepatic OSTalpha and OSTbeta mRNA increased 3- and 32-fold, respectively, in patients with PBC compared with controls, whereas expression of Ostalpha and Ostbeta also increased in the liver of rats and mice following CBDL. In contrast, expression of Ostalpha and Ostbeta mRNA was generally lower in Fxr null mice, and CBDL failed to enhance expression of Ostalpha and Ostbeta compared with wild-type mice. HepG2 cells treated for 24 h with chenodeoxycholic acid, a selective FXR ligand, had higher levels of OSTalpha and OSTbeta mRNA and protein. Increases in OST protein were visualized by confocal microscopy at the plasma membrane. These results indicate that expression of Ostalpha and Ostbeta are highly regulated in response to cholestasis and that this response is dependent on the FXR bile acid receptor.

Primary biliary cirrhosis: when and why does the disease develop?

Primary biliary cirrhosis is a chronic cholestatic liver disease with an autoimmune pathogenesis, that generally develops in adult life, often in perimenopausal age. The clinical features are heterogeneous, ranging from an asymptomatic presentation to end-stage liver disease. Primary biliary cirrhosis is unknown in children and its natural history has yet to be elucidated. Following a Canadian report of primary biliary cirrhosis in two girls (16 and 15 years old), we describe a clinical case developing at 17 years of age. A temporal association between Borrelia Burgdorferi infection and diagnosis of primary biliary cirrhosis was observed.

Hyperhomocysteinemia and hypercoagulability in primary biliary cirrhosis

AIM: To assess the hypercoagulability in PBC and its relationship with homocysteine (HCY) and various components of the haemostatic system.

METHODS: We investigated 51 PBC patients (43F/8M; mean age: 63 ± 13.9 yr ) and 102 healthy subjects (86 women/16 men; 63 ± 13 yr), and evaluated the haemostatic process in whole blood by the Sonoclot analysis and the platelet function by PFA-100 device. We then measured HCY (fasting and after methionine loading), tissue factor (TF), thrombin-antithrombin complexes (TAT), D-dimer (D-D), thrombomodulin (TM), folic acid, vitamin B6 and B12 plasma levels. C677T 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphism was analyzed.

RESULTS: Sonoclot RATE values of patients were significantly (P < 0.001) higher than those of controls. Sonoclot time to peak values and PFA-100 closure times were comparable in patients and controls. TAT, TF and HCY levels, both in the fasting and post-methionine loading, were significantly (P < 0.001) higher in patients than in controls. Vitamin deficiencies were detected in 45/51 patients (88.2%). The prevalence of the homozygous TT677 MTHFR genotype was significantly higher in patients (31.4%) than in controls (17.5%) (P < 0.05). Sonoclot RATE values correlated significantly with HCY levels and TF.

CONCLUSION: In PBC, hyper-HCY is related to hypovitaminosis and genetic predisposing factors. Increased TF and HCY levels and signs of endothelial activation are associated with hypercoagulability and may have an important role in blood clotting activation.

Kupffer cells abrogate cholestatic liver injury in mice

BACKGROUND & AIMS

Biliary obstruction and cholestasis can cause hepatocellular apoptosis and necrosis. Ligation of the common bile duct in mice provides an excellent model in which to study the underlying mechanisms. Kupffer cells play a key role in modulating the inflammatory response observed in most animal models of liver injury. This study was performed to determine the role of Kupffer cells in the injury attending cholestasis.

METHODS

Mice were not treated or were rendered Kupffer cell-depleted by intravenous inoculation of multilamellar liposome-encapsulated dichloromethylene diphosphonate, the common bile duct was ligated and divided; sham-operated animals served as controls. Similarly, interleukin-6 (IL-6)-deficient and tumor necrosis factor-receptor-deficient mice underwent bile duct ligation (BDL) or sham operations.

RESULTS

Serum alanine transaminase levels were increased in all BDL mice at 3 days after surgery, but were significantly higher in IL-6-deficient mice or mice rendered Kupffer cell-depleted before ligation. Histologic examination of BDL livers showed portal inflammation, neutrophil infiltration, bile duct proliferation, and hepatocellular necrosis. Photoimage analyses confirmed more necrosis in the livers of Kupffer cell-depleted and IL-6-deficient animals. Purified Kupffer cells derived from BDL animals produced more IL-6 in culture. Similarly, Kupffer cells obtained by laser capture microdissection from the livers of BDL mice expressed increased levels of IL-6 messenger RNA. Recombinant mouse IL-6 administered 1 hour before BDL completely reversed the increased liver damage assessed otherwise in Kupffer cell-depleted mice.

CONCLUSIONS

These findings indicate that Kupffer cells abrogate cholestatic liver injury by cytokine-dependent mechanisms that include the production of IL-6.

Human leukocyte antigen class II alleles in Caucasian women with primary biliary cirrhosis

In the current study, we investigated human leukocyte antigen (HLA) class II alleles in Caucasian women with primary biliary cirrhosis (PBC), a disease that preferentially affects women. Alleles of DRB1, DQA1, and DQB1 were determined by DNA-based HLA typing for women with PBC (n = 72) and healthy women (n = 381). All study subjects were Caucasian. HLA DRB1*08 was significantly increased in women with PBC compared to healthy women. The increase was primarily due to the DRB1*0801 allele, also the most common DRB1*08 allele among controls. DQB1*04 and DQA1*0401 were significantly increased. DRB1*1501, DQA1*0102, and DQB1*0602 were associated with decreased risk. Analyses conducted comparing parous women with PBC to parous healthy women (n = 68 and n = 282, respectively) yielded similar significant results. Although the DRB1*08-DQA1*0401-DQB1*04 haplotype was significantly associated with PBC, consistent with other studies, this haplotype nevertheless represented only 19% (14/72) of all PBC patients and can account for only a minority of the risk of PBC.

The effect of ursodeoxycholic acid therapy on the natural course of primary biliary cirrhosis

BACKGROUND AND AIMS

We used a multistate modeling approach to assess the effect of ursodeoxycholic acid (UDCA) therapy on the natural course of primary biliary cirrhosis (PBC), which remains controversial.

METHODS

Our population included 262 patients with PBC who had received 13-15 mg/kg UDCA daily for a mean of 8 years (range, 1-22 years). Data were analyzed using a multistate Markov model, with histologic stage progression, death, and orthotopic liver transplantation (OLT) as main end points. Survival without OLT was compared with that predicted by the updated Mayo model and with the expected survival in the control population.

RESULTS

Forty-five patients developed cirrhosis, 20 underwent OLT, and 16 died by the censor date. Ten deaths were due to liver disease. The overall survival rates were 92% at 10 years and 82% at 20 years. Survival rates without OLT were 84% and 66% at 10 and 20 years, respectively, which were slightly lower than the survival rate of an age- and sex-matched control population (relative risk [RR], 1.4; P = .1) but better than the spontaneous survival rate as predicted by the updated Mayo model (RR, .5; P < .01). The survival rate of patients in stage 1 and 2 was similar to that in the control population (RR, .8; P = .5), whereas the probability of death or OLT remained significantly increased in treated patients in late histologic stages (RR, 2.2; P < .05).

CONCLUSIONS

Treatment with UDCA alone normalizes the survival rate of patients with PBC when given at early stages. However, there is a continued need for new therapeutic options in patients with advanced disease.

Genetic polymorphisms influencing xenobiotic metabolism and transport in patients with primary biliary cirrhosis

Epidemiological data suggest that environmental factors may trigger autoimmunity in genetically susceptible individuals. In primary biliary cirrhosis (PBC), it has been postulated that halogenated xenobiotics can modify self-molecules, facilitating the breakdown of tolerance to mitochondrial antigens. The transport and metabolism of xenobiotics is highly dependent on key genetic polymorphisms that alter enzymatic phenotype. We analyzed genomic DNA from 169 patients with PBC and 225 geographically and sex-matched healthy subjects for polymorphisms of genes coding for cytochromes P450 (CYPs) 2D6 (CYP2D6*4, CYP2D6*3, CYP2D6*5, and CYP2D6*6) and 2E1 (cl/c2), multidrug resistance 1 (MDR1 C3435T) P-glycoprotein, and pregnane X receptor (PXR C-25385T, C8055T, and A7635G). We compared the genotype frequencies in patients and controls and also correlated polymorphisms with PBC severity. The distributions of the studied genotypes did not significantly differ between patients and controls. However, when clinical characteristics of patients with PBC were compared according to genotype, the CYP2E1 c2 allele was associated with signs of more severe disease. In conclusion, genetic polymorphisms of CYP 2D6 and 2E1, PXR, and MDR1 do not appear to play a role in the onset of PBC.

Long-term outcome of liver transplantation in patients with PSC: a comparative analysis with PBC

BACKGROUND

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are reported to have the best outcomes after liver transplantation. Based on excellent 5-yr survival results after transplantation, it has been suggested that PSC patients may benefit from "preemptive" transplantation to reduce the risk of cholangiocarcinoma. In this study, we compared 10-yr survival of patients with PSC and PBC using a large database after adjusting for other confounding risk factors.

METHODS

The United Network for Organ Sharing (UNOS) database of all patients who had liver transplantation from 1987 to 2001 was used for analysis after excluding patients with multiple organ transplantation, children, and incomplete data.

RESULTS

Patients with PSC (n = 3,309) were younger than those with PBC (n = 3,254). Retransplantation rate was high in PSC (12.4%vs 8.5%; p< 0.01), and PSC was an independent predictor for retransplantation on multivariate analysis. Cox regression analysis showed that PSC patients had significantly lower graft and patient survival compared to PBC patients after adjusting for other risk factors. Lower survival in PSC became apparent 7 yr after transplantation.

CONCLUSIONS

Patients with PSC had a higher retransplantation rate and lower survival when compared to PBC. Based on this analysis, we do not recommend preemptive liver transplantation for patients with PSC.

Cholestatic syndromes

Further insights into the cellular and molecular mechanisms underlying hepatobiliary transport function and its regulation now permit a better understanding of the pathogenesis and treatment options of cholestatic liver diseases. Identification of the molecular basis of hereditary cholestatic syndromes will result in an improved diagnosis and management of these conditions. New insights into the pathogenesis of extrahepatic manifestations of cholestasis (eg, pruritus) have facilitated new treatment strategies. Important new studies have been published about the pathogenesis, clinical features, diagnosis, and treatment of primary biliary cirrhosis, primary sclerosing cholangitis, cholestasis of pregnancy, total parenteral nutrition-induced cholestasis, drug-induced cholestasis, and viral cholestatic syndromes.

A rapid non-enzymatic method for the preparation of HMW DNA from blood for RFLP studies

AIMS

To define a new histological staging and grading system for primary biliary cirrhosis (PBC), to provide more information reflecting clinical laboratory data and the prognosis to hepatologists.

METHODS AND RESULTS

First, 17 histological lesions of PBC were scored in 188 needle liver biopsy specimens. Factor analysis yielded three independent groups of factors: factor 1 (fibrosis, fibrous piecemeal necrosis, orcein-positive granules, bile plugs, Mallory bodies, feathery degeneration, bile duct loss and atypical ductular proliferation); factor 2 (portal inflammation, eosinophilic infiltration, lymphoid follicles, epithelioid granulomas, interface hepatitis and chronic cholangitis); and factor 3 (interface hepatitis, lobular hepatitis, acidophilic bodies and pigmented macrophages). The eight findings of factor 1, but not factors 2 and 3, were significantly correlated with clinical laboratory data and scores in the Mayo Clinic's prognostic model. Factor 1 lesions may reflect histological progression (staging), while factor 2 and 3 lesions may relate to necroinflammatory activity (grading). Then, we devised a staging and grading system using three lesions (bile duct loss, fibrosis and orcein-positive granules) from factor 1 and three from factors 2 and 3 (chronic cholangitis, interface hepatitis and lobular hepatitis).

CONCLUSION

This new system might provide more pathological information on PBC patients for hepatologists.