Primary biliary cirrhosis

Natural killer T cells exacerbate liver injury in a transforming growth factor beta receptor II dominant-negative mouse model of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an organ-specific autoimmune liver disease characterized by the presence of antimitochondrial antibodies and the destruction of small intrahepatic bile ducts with portal inflammation. In previous studies, we reported that both CD1d expression and the frequency of CD1d-restricted natural killer T (NKT) cells were increased in the livers of patients with PBC. To define a specific role of CD1d-restricted NKT cells in the pathogenesis of PBC, particularly early events, we investigated the function of hepatic CD1d-restricted NKT cells in our transforming growth factor beta (TGF-beta) receptor II dominant-negative (dnTGFbetaRII) mouse model of PBC. We generated CD1d(-/-) and CD1d(+/-) dnTGFbetaRII mice and performed a comparative study of liver immunopathology. We report herein that these dnTGFbetaRII mice demonstrate a massive increase of hyperactive CD1d-restricted NKT cells within the hepatic tissues. CD1d(-/-)dnTGFbetaRII mice, which lack CD1d-restricted CD1d-restricted NKT cells, exhibit significantly decreased hepatic lymphoid cell infiltrates and milder cholangitis compared with CD1d(+/-)dnTGFbetaRII mice. Interestingly, there was a significant increase in the production of interferon-gamma in hepatic CD1d-restricted NKT cells activated by alpha-galactosylceramide in young but not older dnTGFbetaRII mice, suggesting an age-dependent role of CD1d-restricted NKT cells.

CONCLUSION

These data demonstrate that CD1d-restricted NKT cells in dnTGFbetaRII mice are a critical factor in liver injury.

Comparison of the clinical features of Japanese patients with primary biliary cirrhosis in 1999 and 2004: utilization of clinical data when patients applied to receive public financial aid

BACKGROUND

In Asia there are few reports considering time intervals in the examination of clinical features of primary biliary cirrhosis (PBC). Therefore, we tried to compare the characteristics of patients with PBC in two different years.

METHODS

In two fiscal years (1999 and 2004), 9,761 and 13,142 patients with symptomatic PBC were registered to receive public financial aid from the Ministry of Health, Labour and Welfare of Japan, respectively. For the present study, clinical data from 2,127 patients in 1999 and 6,423 ones in 2004 were available. We compared the data in the two different years, including sex, age, major symptoms, and laboratory data.

RESULTS

Male/female ratios were the same figure (0.13 for 1999 and 2004). The median age was significantly older in 2004 than in 1999 (59 years for 1999, 63 years for 2004, respectively, p<0.01). Jaundice and esophageal varices were found significantly less frequent in 2004 than in 1999 (p<0.01 for each item). Levels of total bilirubin, γ-glutamyl transpeptidase (γ-GTP), total cholesterol, and immunoglobulin M were significantly lower in 2004 than in 1999 (p< 0.02 for total bilirubin, and p<0.01 for other each item). The positive rate of antimitochondrial antibodies was significantly higher in 1999 than in 2004 (87.0% for 1999, 83.5% for 2004, respectively, p<0.01)). Complicated autoimmune dis­eases such as Sjögren's syndrome, rheumatoid arthritis, and chronic thyroiditis were found significantly more frequent in 2004 than in 1999 (p<0.01 for each item).

CONCLUSIONS

Among the patients with PBC in 2004, an increase in median age, and lower levels of laboratory data such as γ-GTP have been found compared to 1999. These results may show an accu­mulation of patients with better prognosis and the recent medical progress in controlling patients with PBC.

Screening for specific biomarkers in serum for diagnosis of primary biliary cirrhosis using proteomic fingerprint technology

AIM: To screen for the potential protein biomarkers in serum for the diagnosis of primary biliary cirrhosis (PBC) using proteomic fingerprint technology.

METHODS: Proteomic fingerprint technology combining magnetic beads with MALDI-TOF-MS was used to profile and compare the serum proteins from 44 patients with PBC, 32 patients with other hepatic diseases and 43 healthy blood donors. Proteomic patterns associated with PBC were identified by Biomarker Patterns Software. Model of biomarkers was constructed and evaluated using the Biomarker Patterns Software.

RESULTS: A total of 69 discriminating m/z peaks were identified that were related to PBC (P < 0.05). The model of biomarkers constructed by the Biomarker Patterns Software based on the four biomarkers (3445, 4260, 8133 and 16290) generated excellent separation between the PBC and control groups. The sensitivity was 93.3% and the specificity was 95.1%. Blind test data indicated a sensitivity of 92.9% and a specificity of 82.4%.

CONCLUSION: Biomarkers for PBC can be discovered in serum by MALDI-TOF-MS combining the use of magnetic beads. The pattern of combined markers provides a powerful and reliable diagnostic method for PBC with a high sensitivity and specificity.

Primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology characterized by injury of the intrahepatic bile ducts that may eventually lead to liver failure. Affected individuals are usually in their fifth to seventh decades of life at time of diagnosis, and 90% are women. Annual incidence is estimated between 0.7 and 49 cases per million-population and prevalence between 6.7 and 940 cases per million-population (depending on age and sex). The majority of patients are asymptomatic at diagnosis, however, some patients present with symptoms of fatigue and/or pruritus. Patients may even present with ascites, hepatic encephalopathy and/or esophageal variceal hemorrhage. PBC is associated with other autoimmune diseases such as Sjogren's syndrome, scleroderma, Raynaud's phenomenon and CREST syndrome and is regarded as an organ specific autoimmune disease. Genetic susceptibility as a predisposing factor for PBC has been suggested. Environmental factors may have potential causative role (infection, chemicals, smoking). Diagnosis is based on a combination of clinical features, abnormal liver biochemical pattern in a cholestatic picture persisting for more than six months and presence of detectable antimitochondrial antibodies (AMA) in serum. All AMA negative patients with cholestatic liver disease should be carefully evaluated with cholangiography and liver biopsy. Ursodeoxycholic acid (UDCA) is the only currently known medication that can slow the disease progression. Patients, particularly those who start UDCA treatment at early-stage disease and who respond in terms of improvement of the liver biochemistry, have a good prognosis. Liver transplantation is usually an option for patients with liver failure and the outcome is 70% survival at 7 years. Recently, animal models have been discovered that may provide a new insight into the pathogenesis of this disease and facilitate appreciation for novel treatment in PBC.

Serum autoantibodies: a road map for the clinical hepatologist

The widespread use of serum autoantibodies in the practice of clinical hepatology has led to novel challenges in the interpretation of results obtained with routine techniques, such as indirect immunofluorescence (IIF) or with recombinant antigens. In fact, the laboratory methods are often overlooked factors in the interpretation of data by the bedside clinician despite being critical in the interpretation of data. Importantly, the sensitivity and specificity of these serum hallmarks are not defined in all cases. Taken altogether, these observations point towards the need for a systematic discussion of autoimmune serology in the clinical setting of everyday practice. The target of this review article is therefore, to illustrate the current knowledge and available experimental evidence to guide the diagnostic and prognostic decision making in autoimmune and viral chronic liver diseases.

Impaired indoleamine 2,3-dioxygenase production contributes to the development of autoimmunity in primary biliary cirrhosis

The immunomodulatory effects of the tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) have been elucidated at a cellular level and implicated in the pathogenesis of several complex diseases. Defects within the regulatory T cell compartment are one of the characteristics of primary biliary cirrhosis (PBC), an autoimmune chronic cholestatic liver disease, a phenotype that has also been shown in disease-mimicking animal models of this disease. We hypothesized that IDO dysregulation could lead to altered frequency and/or function of T cells at the level of antigen processing/presentation and we thus investigated IDO in peripheral monocytes and bile duct cells from patients with PBC. Both expression and activation manifested an impaired IFN-gamma response in peripheral monocytes while a peculiar IDO expression profile in bile duct cells characterized early stage PBC. Further, we observed an increased frequency of a gain-of-function SNP within the TGF-beta promoter region, a molecule known to suppress IDO transcription. In conclusion, we submit that an impaired IDO induction characterizes PBC and might represent a contributing factor in disease pathogenesis in association with several specific defects in the target tissue.

Effect of tumor necrosis factor alpha antagonists in a patient with rheumatoid arthritis and primary biliary cirrhosis

The proinflammatory cytokine tumor necrosis factor alpha seems to play a major role in the pathogenesis of both rheumatoid arthritis and primary biliary cirrhosis. We describe the case of a 46-year-old female patient with rheumatoid arthritis and concomitant primary biliary cirrhosis treated with anti-tumor necrosis factor alpha agents. During infliximab treatment we observed a poor clinical response and persistence of liver function test abnormalities. After infliximab interruption the levels of alkaline phosphatase dropped and had nearly reached normal values when etanercept was started. This new therapeutic regimen was well tolerated with joint clinical improvement and normalization of alkaline phosphatase. This single case shows that etanercept therapy maintained liver enzymes within the normal range and controlled the arthritis with a 30-month follow-up whereas infliximab did not account for similar results.

Successful radiofrequency ablation therapy for hepatocellular carcinoma in a male patient with early stage primary biliary cirrhosis and positive serum hepatitis B core antibody

Hepatocellular carcinoma (HCC) occurring in a 66-year-old male patient with early stage primary biliary cirrhosis (PBC) was successfully treated by radiofrequency ablation (RFA) therapy. He was diagnosed with PBC based on the findings of pruritus, elevated serum alkaline phosphate level and positive serum antimitochondrial antibody in 2005. The serologic tests for hepatitis B surface antigen, hepatitis B surface antibody and hepatitis C virus antibody were all negative. But antibody against hepatitis B core antigen was positive. Abdominal ultrasonography and dynamic computed tomography revealed 1 hypervascular tumor, 2.6 cm in diameter, in segment V of the liver in 2007. Liver biopsy showed a moderately differentiated HCC. Non-tumorous liver was compatible with Scheuer's classification of stage II PBC. The tumor was successfully treated by RFA. This case report demonstrates that HCC can arise from precirrhotic PBC and can be successfully treated by RFA. Regular surveillance for HCC is warranted for all patients with PBC, irrespective of stage.

Primary biliary cirrhosis in female subjects with sicca-associated antibodies

The aim of this study is to clarify the time course of primary biliary cirrhosis (PBC) in subjects possessing anticentromere antibodies (ACA), anti-Ro, and/or anti-La antibodies, and who used alkaline phosphatase (ALP) as a serological marker for PBC. Female subjects (n = 165), who had at least one of ACA, anti-Ro, and/or anti-La, were enrolled in this study. Groups A (ACA alone, n = 44), B (anti-Ro alone, n = 54), E (anti-Ro and anti-La, n = 52), and DFG (ACA with anti-Ro and/or anti-La, n = 14) were analyzed. Healthy females (n = 65) were used as a control. The frequencies of the PBC in groups A (13.6%) and DFG (14.3%) were higher than those in groups B (1.9%) and E (0.0%). The ALP levels increased with age in groups A and DFG and slightly increased with age in groups B and C, and the control group. After correcting for age by analysis of covariance, a comparison of ALP levels among the groups not having anti-M(2) was as follows: group A falling dots group DFG > group B falling dots group E falling dots the control group. The subjects with ACA might thus have PBC more frequently than either those with anti-Ro and/or anti-La, or the control subjects.

X monosomy in female systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease, predominantly occurring in women of childbearing age. SLE, like several other autoimmune diseases, is characterized by a striking female predominance and, although sex hormone influences have been suggested as an explanation for this phenomenon, definitive data are still unavailable. Our group recently reported an increased X monosomy in lymphocytes of women, affected with primary biliary cirrhosis (PBC), systemic sclerosis (SSc), and autoimmune thyroiditis (AITD) in comparison to healthy women, thus suggesting the involvement of this chromosome in female predominance and in the deregulation of the immune system that characterizes autoimmunity. We have now evaluated X monosomy rates in SLE using fluorescence in situ hybridization (FISH) on peripheral mononuclear white blood cells (PBMCs) from female patients compared to healthy age-matched controls. In addition, because of a previous finding of microchimerism as a pathogenetic cause of a number of autoimmune diseases, we investigated the presence of cells carrying the Y chromosome. We did not identify an increased X monosomy in women with SLE compared to controls (P = 0.3960, SLE vs. HCs, Student's t-test), thus suggesting that a different mechanism of immune deregulation might be predominant in the female population of patients with SLE.

Genetic polymorphisms of transforming growth factor beta-1 promoter and primary biliary cirrhosis in Japanese patients

As suggested by concordance rates in twins, genetic factors are critical to the susceptibility and progression of primary biliary cirrhosis (PBC). Among cytokines, transforming growth factor beta-1 (TGF-beta1) plays an important role in autoimmunity and liver fibrosis and a TGF-beta1 receptor knockout mouse has been recently proposed as a model for PBC. The promoter region of the TGF-beta1 gene has two single nucleotide polymorphisms (SNPs) at positions -800 and -509, which influence serum concentrations of latent and active TGF-beta1. We studied genomic DNA from 65 Japanese patients with PBC and 71 matched healthy controls for the association of TGF-beta1 SNPs analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with susceptibility and disease progression of PBC. The -800 G to A SNP was not found in the Japanese population and no significant difference in the distribution of TGF-beta1 promoter gene -509 SNP was found between PBC cases and controls. Further, TGF-beta1 genotypes failed to correlate with clinical parameters, including histological stage and prognostic score. In conclusion, the TGF-beta1 promoter gene SNPs are not associated with disease susceptibility or progression in Japanese patients with PBC.

The unfolded protein response in hereditary haemochromatosis

To cope with the accumulation of unfolded or misfolded proteins the endoplasmic reticulum (ER) has evolved specific signalling pathways collectively called the unfolded protein response (UPR). Elucidation of the mechanisms governing ER stress signallinghas linked this response to the regulation of diverse physiologic processes as well as to the progression of a number of diseases. Interest in hereditary haemochromatosis (HH) has focused on the study of proteins implicated in iron homeostasis and on the identification of new alleles related with the disease. HFE has been amongst the preferred targets of interest, since the discovery that its C282Y mutation was associated with HH. However, the discrepancies between the disease penetrance and the frequency of this mutation have raised the possibility that its contribution to disease progression might go beyond the mere involvement in regulation of cellular iron uptake. Recent findings revealed that activation of the UPR is a feature of HH and that this stress response may be involved in the genesis of immunological anomalies associated with the disease. This review addresses the connection of the UPR with HH, including its role in MHC-I antigen presentation pathway and possible implications for new clinical approaches to HH.

Quality of life and everyday activities in patients with primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is generally a slowly progressive disease that may lead to cirrhosis and liver failure. However, patients with PBC often suffer from a variety of symptoms long before the development of cirrhosis that include issues of daily living that have an impact on their work environment and their individual quality of life. We therefore examined multiple parameters by taking advantage of the database of our cohort of 1032 patients with PBC and 1041 matched controls. The data were obtained from patients from 23 tertiary referral centers throughout the United States and from rigorously matched controls by age, sex, ethnicity, and random-digit dialing. The data showed that patients with PBC were more likely than controls to have significant articular symptoms, a reduced ability to perform household chores, and the need for help with routine activities. Patients with PBC rated their overall activity similar or superior to that of controls; however, more of them reported limitations in their ability to carry out activities at work or at home and difficulties in everyday activities. PBC cases also more frequently reported limitations in participating in certain sports or exercises and pursuing various hobbies; however, they did not report significant limitations in social activities. In a multivariable analysis, household income, a diagnosis of systemic lupus erythematosus, limitations in work activities, a reduction in work secondary to disability, and church attendance were independently increased in PBC cases with respect to controls.

CONCLUSION

Our data indicate that the quality of life of patients with PBC in the United States is generally well preserved. Nevertheless, patients with PBC suffer significantly more than controls from a variety of symptoms that are beyond the immediate impact of liver failure and affect their lifestyle, personal relationships, and work activities.

Overlap syndromes with autoimmune hepatitis in chronic cholestatic liver diseases

Conditions exhibiting features of two different autoimmune liver diseases are commonly designated overlap syndromes, although there is no current agreement on what constitutes an overlap syndrome or specific diagnostic criteria. As in the classic autoimmune liver diseases, such as autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC), the etiology is unknown but presumed to be related to alterations of immune regulation. Distinction of these clinical entities is important for management as outcomes may differ from outcomes of patients with diagnosis of classic autoimmune liver diseases. Due to their presumed rarity, no large therapeutic trials are available and treatment of overlap conditions is empirical and based upon extrapolation of data from the primary autoimmune liver diseases. PBC-AIH overlap is the most frequently described overlap syndrome and may be associated with a poor prognosis. This may represent an important and unrecognized cause of resistance to ursodeoxycholic acid in patients with PBC. PSC-AIH overlap is less commonly reported. Prognosis may be better than in patients with PSC alone; however, worse than in patients with AIH alone. Further studies are needed for determining diagnosis, natural history and optimal therapeutic strategies of overlap syndromes of autoimmune liver disease.

Anti-CD16 autoantibodies and delayed phagocytosis of apoptotic cells in primary biliary cirrhosis

Primary biliary cirrhosis is characterized by chronic hepatic inflammation and immune mediated apoptosis of bile duct epithelial cells. Delayed macrophage phagocytosis of opsonized apoptotic cells, noted in other autoimmune diseases, may promote inflammation. Recent studies suggest serum anti-CD16 autoantibodies contribute to impaired macrophage phagocytosis by blocking complement receptor 3 (CR3) signaling via CD16. Therefore, serum anti-CD16 levels and the ability of monocyte derived macrophages from individuals with PBC to phagocytosis apoptotic cells were compared to controls. The mean level of anti-CD16 IgM autoantibodies (0.86+/-0.62 v. 0.35+/-0.22, respectively, p=0.031) was increased in PBC compared to control sera, and mean PBC phagocytosis of opsonized apoptotic cells was significantly decreased compared to controls (23.9+/-12.2% v. 43.9+/-14.4%, respectively, p=0.020). However, PBC phagocytosis of opsonized apoptotic cells was not significantly affected by the presence or absence of autologous serum (20.8+/-13.5% v. 23.9+/-12.2%, respectively, p=0.560). PBC phagocytosis of opsonized apoptotic cells inversely correlated with CD16 (and CR3) expression levels on Day 5 after culture in the presence or absence of autologous serum (r=-0.546, p=0.033 and r=-0.519, p=0.042, respectively). Phagocytosis of non-opsonized apoptotic cells did not correlate with CD16 or CR3 expression (p>0.050). In conclusion, PBC macrophage phagocytosis of opsonized apoptotic cells is impaired, irrespective of serum factors and may increase hepatic inflammation.

Peripheral tolerance and the qualitative characteristics of autoreactive T cell clones in primary biliary cirrhosis

Primary biliary cirrhosis is characterized by autoreactive T cells specific for the mitochondrial Ag PDC-E2(163-176). We studied the ability of eight T cell clones (TCC) specific for PDC-E2(163-176) to proliferate or become anergic in the presence of costimulation signals. TCC were stimulated with either human PDC-E2(163-176), an Escherichia coli 2-oxoglutarate dehydrogenase mimic (OGDC-E2(34-47)), or analogs with amino acid substitutions using HLA-matched allogeneic PBMC or mouse L-DR53 fibroblasts as APC. Based on their differential responses to these peptides (human PDC-E2(163-176), E. coli OGDC-E2(34-47)) in the different APC systems, TCC were classified as costimulation dependent or independent. Only costimulation-dependent TCC could become anergic. TCC with costimulation-dependent responses to OGDC-E2 become anergic to PDC-E2 when preincubated with mimic, even if costimulation is independent for PDC-E2(163-176). Anergic TCC produced IL-10. One selected TCC could not become anergic after preincubation with PDC-E2(163-176)-pulsed L-DR53 but became anergic using L-DR53 pulsed with PDC-E2 peptide analogs with a substitution at a critical TCR binding site. TCC that only respond to peptide-pulsed PBMC, but not L-DR53, proliferate with peptide-pulsed CD80/CD86-transfected L-DR53; however, anergy was not induced with peptide-pulsed L-DR53 transfected with only CD80 or CD86. These data highlight that costimulation plays a dominant role in maintaining peripheral tolerance to PBC-specific Ags. They further suggest that, under specific circumstances, molecular mimicry of an autoantigen may restore rather than break peripheral tolerance.

Transplantation trends in primary biliary cirrhosis

BACKGROUND & AIMS

Ursodeoxycholic acid (UDCA) has shown efficacy in primary biliary cirrhosis (PBC), a chronic, slowly progressive disease. We hypothesized that UDCA use would reduce the need for liver transplantation in PBC. Our study's aim was to assess liver transplantation requirements in PBC over a 12-year period. For comparison, we studied patients with primary sclerosing cholangitis (PSC) because it shares similar characteristics to PBC, but with a decreased response to UDCA.

METHODS

PBC and PSC transplant data of first-time liver recipients from the United Network for Organ Sharing database were collected from 1995 to 2006.

RESULTS

The absolute number of liver transplantations in the United States increased an average of 249 transplants per year (P < .001). The absolute number of transplants performed for PBC decreased an average of 5.4 cases per year (P = .004). The absolute number of transplantations for PSC showed no statistical change (P = .621). The trends for the absolute number of individuals added to the transplant waitlist showed a similar pattern: (1) an increase in total listings for transplants of all diagnoses (beta = 265; P = .001); (2) a decrease in PBC (beta = -12.1; P < .001); (3) and no change for PSC (beta = -5.434; P = .083).

CONCLUSIONS

The liver transplantation burden of PBC in the United States decreased between 1995 and 2006. This is despite an increase in total liver transplants and no change in transplant rates for PSC.

Antimitochondrial antibodies of immunoglobulin G3 subclass are associated with a more severe disease course in primary biliary cirrhosis

BACKGROUND/AIMS

Primary biliary cirrhosis (PBC) is characterised by the presence of immunoglobulin (Ig) G antimitochondrial antibodies (AMA), which are routinely detected by indirect immunofluorescence (IFL) using composite rodent tissue substrate. The IgG subclass distribution and clinical significance of IFL-detected AMA in patients with PBC have not been previously studied in detail.

METHODS

We have examined IgG subclass-specific AMA detected by IFL on rodent liver, kidney and stomach tissue substrate using affinity-purified IgG subclass monospecific antisera as revealing reagents in 95 AMA-positive PBC patients from Greece.

RESULTS

AMA of any of the IgG1, IgG2 or IgG3 subclasses were present in 89/95 (93.7%) patients. Among those 89, 55 (61.8%) had IgG1, 2, 3 AMA positivity; eight (9%) had IgG1, 2; seven (7.9%) had IgG2, 3; eight (9%) had IgG1, 3; nine (10.1%) had IgG1 subclass and two (2.2%) single IgG3 AMA reactivity. IgG4 AMA was absent. IgG3 titres were higher than IgG2 and IgG1 (P<0.001) and IgG1 higher than IgG2 (P<0.001). IgG3 AMA-positive patients had a histologically more advanced disease (P<0.01) and were more frequently cirrhotic compared with those who were negative (P<0.01). There was a positive correlation between AMA IgG3 titre and Mayo risk score (r=0.55, P=0.009, Spearman's correlation).

CONCLUSIONS

Our findings suggest that AMA are not restricted to a specific IgG subclass. AMA of the IgG3 subclass are associated with a more severe disease course, possibly reflecting the peculiar ability of this isotype to engage mediators of damage.

Prevalence and incidence of primary biliary cirrhosis are increasing in Finland

OBJECTIVE

To examine the epidemiology of primary biliary cirrhosis (PBC) in Finland and to evaluate whether the possible increase in prevalence was attributable to the increasing incidence, better survival, or both.

MATERIAL AND METHODS

The Hospital Discharge Register, pathology registers, and death certificates for the years 1988 99 were scrutinized, and the patients identified were followed-up for survival until 31 October 2004. The study area covered four university hospital districts: a total of 25 hospitals. The diagnosis of PBC was regarded as definite (or probable) if three (or two) of the following criteria were fulfilled: positive antimitochondrial antibodies, constantly elevated alkaline phosphatase, and compatible liver histology.

RESULTS

In the total population of the study areas, the age-standardized prevalence of PBC increased during the study period from 103 (95% CI: 97-110) to 180 (172-189) per million inhabitants. Incidence increased from 12 (10-14) to 17 (15-20) per million inhabitants per year. The annual average increase in prevalence was 5.1% (4.2-5.9%, p <0.0001) and in incidence 3.5% (0.9%-6.0%, p =0.008). In gender-specific analyses among women, the prevalence of PBC increased from 161 (151-171) to 292 (277-207) per million during the study period and the incidence from 20 (16-24) to 27 (23-32) per million per year. The death rate was 4% per year and half the deaths were from liver-related causes. Survival after diagnosis during the study period lengthened.

CONCLUSIONS

The prevalence of PBC increased in Finland during 1988-99, owing to both the increased incidence and the prolonged survival.

New insights on the molecular and cell biology of human cholangiopathies

Cholangiopathies are diseases of high social impact representing the main indication for liver transplantation in the infanthood and the third in adulthood. Despite the heterogeneous etiology and pathogenesis, cholangiopathies share many different common morphological features and, chronically progress toward a ductupenic condition clinically evidenced by the classical features of a cholestatic syndrome. The primary target of damage in the course of cholangiopathies are cholangiocytes, the epithelia cells lining the biliary tree. A bulk of researches performed in the last decade, highlighted the extraordinary biological properties of cholangiocytes involved in a number of important processes such as bile formation, proliferation, injury repair, fibrosis, angiogenesis and regulation of blood flow. Recent advances on the molecular and cell biology of human cholangiopathies are opening new potential therapeutic perspectives for these diseases.

Recurrence of primary biliary cirrhosis and primary sclerosing cholangitis after liver transplantation in Japan

Although there was some initial controversy, there is now a consensus that primary biliary cirrhosis (PBC) does indeed recur in both cadaveric and living donated allografts. Recurrence rate after deceased donor liver transplantation (LT) was reported to be 10.9-23% at 5 years. In the present study, we reviewed 221 PBC patients who underwent living-donor liver transplantation (LDLT) in Japan. The 5-year overall survival rate was 79%, and the rate of recurrence based on histological findings was 10% (7/70) after a median time of 36 months. Primary immunosuppression, withdrawal of corticosteroids and human leukocyte antigen matches were not associated with the recurrence. Recurrent PBC appears to have little impact on graft function and survival, but this may become a greater problem with longer follow up. It is noteworthy that the 10-year survival of primary sclerosing cholangitis (PSC) patients who underwent LDLT wasfound to be only 39.1% in Japan, whereas that of PBC was 72.9%. Factors associated with the poor prognosis include biliary strictures, hepatobiliary and colorectal malignancies, and recurrence of PSC. In our study, we reviewed 66 patients with PSC who underwent LDLT in Japan. The 5-year survival rate was 72%, and the rate of recurrence diagnosed on histological and cholangiographic findings was 25% (11/44). Well-defined diagnostic criteria and longer studies are required to characterize the nature of recurrent PSC and its impact on graft survival in more detail.

Environmental factors in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease more commonly found in women (with most cases being diagnosed in the fourth to fifth decades of life) that share peculiar features. Among these, serum antimitochondrial autoantibodies (AMA), serum hyper-immunoglobulin M, and progressive destruction of intrahepatic bile ducts are the most common clinical findings. The pathogenesis of the selective destruction of small-duct biliary epithelial cells is still unknown, although an autoimmune mechanism appears likely due to the detection of autoreactive T and B cells. Genetic background is critical in determining susceptibility to the disease, despite the limited associations with alleles within the major histocompatibility complex. However, among other observations, incomplete concordance of the disease in monozygotic twins and epidemiology strongly support a role for environmental factors in PBC onset. Molecular mimicry by either infectious agents or chemicals has been proposed to induce breakdown of immune tolerance in genetically predisposed individuals. This hypothesis is further supported by clinical (risk factors) and experimental evidence obtained also in animal models.

Autoimmune intrahepatic cholangiopathy associated with antiphospholipid antibody syndrome

We report the case of a 26-year-old woman who developed thrombophlebitis in her left leg in 2002, followed by fever, asthenia and headache in 2004. Antinuclear antibodies, antimitochondrial antibodies, anti-liver kidney microsome, anti-Smith, antiphospholipid (aPL) and antineutrophil cytoplasmic antibodies, as well as lupus- anticoagulant activity were positive. Systemic lupus erythematosus (SLE) with aPL syndrome was diagnosed and the patient was treated with azathioprine and heparin. Symptoms persisted and itching arose in the following months. The patient was admitted to our department in January 2005 for jaundice and skin rash. Elevated levels of acute phase proteins and cholestasis and liver necrosis indexes were present. Antinuclear antibodies, aPL and antimitochondrial antibodies (M5) antibodies were positive. Liver histology showed minimal focal hepatocyte necrosis, intrahepatic biliary stasis and intralobular inflammatory cell infiltrate. The absence of clinical signs that are characteristic of SLE as well as the failure to confirm antiSmith antibody positivity led us to rule out a diagnosis of SLE. On the basis of clinical, immunological and histological data, autoimmune intrahepatic cholangiopathy associated with primary aPL syndrome was diagnosed. The patient was treated with intravenous methylprednisolone followed by oral prednisone, warfarin and ursodeoxycholic acid. Liver necrosis and cholestasis indexes rapidly improved within 1 month and progressively reached the normal range. To our knowledge, this is the first description of a patient with an association of intrahepatic cholangiopathy and aPL, thus suggesting that autoimmune liver disease might associate with aPL syndrome.

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

BACKGROUND AND AIMS

Primary biliary cirrhosis (PBC) is characterized by the autoimmune inflammatory response of small intrahepatic bile ducts. Prevalence in Spain is estimated as 61.9 cases per million inhabitants, whereas Northern Europe rates over 200 cases/million. Our objective was to determine the incidence and prevalence of PBC in our health area.

MATERIAL AND METHODS

PBC was defined by the presence of abnormal liver tests (dissociated cholestasis) with positive antimitochondrial antibodies and/or compatible liver histology. Medical records from patients diagnosed between 1990 and 2002 were reviewed retrospectively. The following data were collected: diagnostic data, demographic and analytic data, liver histology and stage and treatment and disease outcome.

RESULTS

In a population of 389 758 inhabitants, 87 patients were diagnosed with PBC. Mean age at diagnosis was 63.9+/-12.6 years. Eighty-four (96.6%) were women. Mean annual incidence was 17.2 per 10 inhabitants and the prevalence at the end of study was 195 per 10. Biopsy was performed in 71 (81.6%) patients, 61 of whom (86%) did not have fibrosis. Time of follow-up was 63.6+/-43.2 (2.28-153.9) months.

CONCLUSION

Incidence and prevalence in our reference area are higher than in some Spanish areas, as per the results previously published; however, they are comparable with those obtained in Northern Europe and the US.

Role of X chromosome defects in primary biliary cirrhosis

Similar to the majority of autoimmune conditions, primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease characterized by a striking female predominance; it is characterized by high titer serum autoantibodies to mitochondrial antigens, elevated serum immunoglobulin M, progressive destruction of intrahepatic bile ducts, and ultimately liver cirrhosis and failure. Familiarity and high concordance rates for the disease among monozygotic twins strongly support the role of genetics in the disease. Experimental efforts have been dedicated by our and other research groups to investigate the role of X chromosome abnormalities (i.e. monosomyrates and inactivation patterns) in autoimmunity. Our recent work has demonstrated enhanced X monosomy in women with PBC as well as two other female-predominant autoimmune diseases, systemic sclerosis and autoimmune thyroid disease. We will review herein the most recent evidence on the role of the X chromosome in PBC onset and discuss the potential implications. Future developments of these findings will be discussed.

The clinical significance of IgA antimitochondrial antibodies in sera and saliva in primary biliary cirrhosis

It still remains unclear how antimitochondrial autoantibodies (AMA) are involved with immunopathogenesis of primary biliary cirrhosis (PBC). We have suggested the potential role of IgA-AMA in damage to epithelial cells in PBC. In the current study, we investigated whether IgA-AMA were detectable in sera and saliva of PBC patients, to examine the association between detectable IgA-type autoantibodies in sera or saliva and progression of liver diseases. Fifty-three patients with PBC were enrolled, and IgA-AMA in sera and saliva were sought by immunoblotting using pork heart mitochondria as antigens. The progression of PBC was determined as Scheuer's classification consisting of four histological stages. We found IgA-AMA, IgA-anti-PDC-E2, and IgA-anti-E3BP in 43/53 (81%), 37/53 (70%), and 35/53 (66%) sera of patients with PBC, but none of controls. The progression of PBC was statistically associated with presence of IgA-anti-PDC-E2 (P = 0.0124), but neither with IgA-AMA (P = 0.1296) nor anti-IgA-E3BP (P = 0.5973). In saliva, detectable IgA-AMA, IgA-anti-PDC-E2, and IgA-anti-E3BP were noted in 12/26 (46%), 6/26 (23%), and 11/26 (42%), respectively. Detection of IgA-anti-PDC-E2 was strongly associated with progression of PBC (P = 0.0002), whereas detection of IgA-AMA and IgA-anti-E3BP were not associated (P = 0.2145 and P = 0.5118). The current findings suggest that the presence of IgA-anti-PDC-E2 in sera or saliva might be associated with progression of PBC, although a prospective study with PBC patients with detectable IgA-anti-PDC-E2 at early stages will be required to conclude the contribution of IgA-anti-PDC-E2 to the progression of PBC.

Antibodies to SS-A/Ro-52kD and centromere in autoimmune liver disease: a clue to diagnosis and prognosis of primary biliary cirrhosis

BACKGROUND

Primary biliary cirrhosis (PBC) may be associated with various rheumatological disorders.

AIM

To investigate the frequency and significance of 'rheumatological' antinuclear antibodies in the field of autoimmune chronic liver disease, with special regard to PBC.

METHODS

We studied 105 patients with PBC, 162 autoimmune liver disease controls (type 1 and 2 autoimmune hepatitis, primary sclerosing cholangitis), 30 systemic lupus erythematosus and 50 blood donors. Sera were tested for the presence of antibodies to extractable nuclear antigens (anti-ENA) by counterimmunoelectrophoresis, enzyme-linked and immunoblot (IB) assay, and for the presence of anti-centromere antibodies (ACA) by indirect immunofluorescence on HEp-2 cells and IB.

RESULTS

The overall prevalence of IB-detected anti-ENA in PBC (30%) was higher than in type 1 autoimmune hepatitis (2.5%, P < 0.0001), type 2 autoimmune hepatitis (0%, P < 0.0001) and primary sclerosing cholangitis (11.5%, P = 0.006) and lower than in systemic lupus erythematosus (53%, P = 0.03). The most frequent anti-ENA reactivity in PBC was anti-SSA/Ro-52kD (28%). ACA were detected by IB in 21% PBC patients and never in the other subjects (P < 0.0001). Anti-SS-A/Ro/52kD positive PBC patients had at the time of diagnosis a more advanced histological stage (P = 0.01) and higher serum levels of bilirubin (P = 0.01) and IgM (P = 0.03) compared with negative ones.

CONCLUSIONS

In the autoimmune liver disease setting, anti-SS-A/Ro-52kD and ACA have a high specificity for PBC and can thus be of diagnostic relevance in anti-mitochondrial antibodies negative cases. If confirmed in further studies with adequate follow-up, anti-SS-A/Ro-52kD antibodies might identify PBC patients with a more advanced and active disease.

Atorvastatin in patients with primary biliary cirrhosis and incomplete biochemical response to ursodeoxycholic acid

Statin therapy may target both hypercholesterolemia and cholestasis in primary biliary cirrhosis (PBC). However, little is known about the efficacy and safety of statins in PBC. The aim of this single-center study was therefore to prospectively examine the effects of atorvastatin on serum markers of cholestasis, aminotransferases, and lipid and bile acid metabolism as well as inflammatory and immunological markers in patients with PBC. Fifteen patients with early-stage PBC and an incomplete biochemical response to ursodeoxycholic acid (UDCA) therapy (defined as alkaline phosphatase 1.5-fold above the upper limit of normal after 1 year) were treated with atorvastatin 10 mg/day, 20 mg/day, and 40 mg/day for 4 weeks, respectively. Serum levels of alkaline phosphatase increased during atorvastatin 20 mg and 40 mg (P < 0.05), whereas leucine aminopeptidase and gamma-glutamyltransferase remained unchanged. No statistical differences in overall serum ALT, AST, bilirubin, and IgM levels were observed. However, atorvastatin was discontinued in 1 out of 15 patients because of ALT 2-fold above baseline, and 2 patients showed ALT elevations 3-fold above the upper limit of normal at the end of the atorvastatin treatment period. Serum total cholesterol and low-density lipoprotein cholesterol levels decreased by 35% and 49%, respectively (P < 0.001). Precursors of cholesterol biosynthesis (lanosterol, desmosterol, lathosterol) showed a similar pattern. No changes in serum bile acid levels and composition were observed during treatment.

CONCLUSION

Atorvastatin does not improve cholestasis in PBC patients with an incomplete biochemical response to UDCA but effectively reduces serum cholesterol levels.

Increased prevalence of antimitochondrial antibodies in first-degree relatives of patients with primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disorder that can progress to cirrhosis, shortening life expectancy. PBC patients are often asymptomatic, present with biochemical cholestasis, and test positive (>or=90%) for antimitochondrial antibodies (AMAs) in serum. Although AMA positivity without biochemical cholestasis may indicate increased risk of future PBC development, the contribution of these antibodies to pathogenesis remains enigmatic. Environmental risks and genetic determinants are likely implicated in PBC etiology. Given the familial aggregation of PBC, we hypothesized that AMAs also aggregate among relatives of PBC probands. We investigated the prevalence of AMAs in first-degree relatives (FDRs) of PBC probands to examine whether AMAs aggregate in such pedigrees. Using a PBC family registry, we prospectively screened for AMAs in the serum of 306 FDRs in 145 pedigrees, 350 PBC probands, and 196 controls who were age-matched, sex-matched, race-matched, and residence-matched to probands. The prevalence of AMA in FDRs and controls was 13.1% and 1%, respectively. Greater prevalence of AMA was found in female FDRs of PBC probands [sisters (20.7%), mothers (15.1%), and daughters (9.8%)] than in male FDRs [brothers (7.8%), fathers (3.7%), and sons (0%)].

CONCLUSIONS

AMAs aggregate among FDRs of PBC probands. Our data have clinical implications for FDRs of PBC probands because AMA positivity may suggest susceptibility to PBC. Thus, the identification and follow-up of these relatives may lead to earlier disease diagnosis and treatment. Furthermore, if AMA development is heritable, this trait will provide a basis to dissect the genetic predisposition to PBC.

Altered expression of TLR homolog RP105 on monocytes hypersensitive to LPS in patients with primary biliary cirrhosis

BACKGROUNDS/AIMS

Toll-like receptors (TLRs) have emerged as a key component of the innate immune system that triggers antimicrobial responses. Altered monocyte responses to ligands for TLRs have been reported in patients with primary biliary cirrhosis (PBC), yet the precise mechanism remains unknown.

METHODS

We investigated in vitro responses to a TLR4 ligand, lipopolysaccharide (LPS), using peripheral blood mononuclear cells and monocytes from 25 patients with PBC, 10 patients with chronic viral hepatitis (CVH), and 20 healthy individuals.

RESULTS

After stimulation with LPS, we found significantly higher amounts of IL-1beta, IL-6, and IL-8 production in PBC patients. Through the TLR4 signaling pathway, activation of NF-kappaB and expression of MyD88 mRNA were significantly increased in PBC patients, and the level of TLR4 expression was significantly increased on PBC monocytes as compared with CVH patients and controls. Of significance, the surface expression of RP105, which has recently been shown to be involved in negative regulation of TLR4 signaling, on PBC monocytes was significantly decreased in comparison with CVH patients (P=0.016) and controls (P<0.001).

CONCLUSIONS

These results suggest that expression of RP105 and TLR4 is altered on PBC monocytes, which appear to be hypersensitive to LPS, resulting in increased secretion of pro-inflammatory cytokines.

Ursodeoxycholic acid for patients with primary biliary cirrhosis: an updated systematic review and meta-analysis of randomized clinical trials using Bayesian approach as sensitivity analyses

OBJECTIVES

Ursodeoxycholic acid (UDCA) is used for primary biliary cirrhosis (PBC), but the beneficial effects remain controversial.

METHODS

We performed an updated systematic review to evaluate the benefits and harms of UDCA in patients with PBC. We included randomized clinical trials evaluating UDCA versus placebo or no intervention in patients with PBC. The primary outcomes, mortality and mortality or liver transplantation, were reported as relative risk (RR) with 95% confidence interval (CI). Meta-regression was used to investigate the associations between UDCA effects and the trial's risk of bias, UDCA dose, duration, and PBC severity at trial entry. We used Bayesian meta-analytic approaches as sensitivity analyses.

RESULTS

Sixteen randomized clinical trials (1,447 patients) evaluating UDCA versus placebo or no intervention were identified. Over half of the trials had high risk of bias. Comparing with placebo or no intervention, UDCA did not significantly affect mortality (RR 0.97, 95% CI 0.67-1.42) and mortality or liver transplantation (RR 0.92, 95% CI 0.71-1.21). The findings were supported by the Bayesian meta-analyses. Meta-regression analyses suggested that UDCA effects seem to be associated with patient's disease severity and trial duration. UDCA did not improve pruritus, fatigue, autoimmune conditions, liver histology, or portal pressure. UDCA seemed to improve biochemical variables, such as serum bilirubin, and ascites and jaundice, but the findings were based on few trials with sparse data. The use of UDCA was significantly associated with adverse events, mainly weight gain.

CONCLUSIONS

This updated systematic review did not demonstrate any benefit of UDCA on mortality and mortality or liver transplantation in patients with PBC.

Immunoglobin G4-hepatopathy: association of immunoglobin G4-bearing plasma cells in liver with autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is characterized by high serum immunoglobin (Ig) G4 concentrations, lymphoplasmacytic inflammation, and a favorable response to corticosteroid treatment. Since liver dysfunction is frequently seen in AIP patients, we investigated hepatic histopathology and its clinical significance in patients with AIP. We examined the clinical features, histology, and immunoglobin G (IgG)4-bearing plasma cell infiltration of liver biopsies from 17 patients with AIP and 63 patients with either autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, or chronic viral hepatitis and histological changes in the 7 of 17 livers before and after glucocorticoid therapy. The liver histology of AIP was classified into 5 patterns: evident portal inflammation with or without interface hepatitis (6 cases), large bile-duct obstructive features (8 cases), portal sclerosis (8 cases), lobular hepatitis (5 cases), and canalicular cholestasis (4 cases); some of the histological features coexisted in the same liver. The number of IgG4-bearing plasma cells was significantly higher in AIP patients than controls (P < 0.01), and was significantly correlated with serum IgG4 concentration (P = 0.0014, r = 0.709). Glucocorticoid therapy reduced IgG4-bearing plasma cell infiltration in the liver (P = 0.031) and ameliorated other histological findings. In conclusion, virtually all AIP liver biopsies showed evidence of various pathological changes and infiltration of IgG4-bearing plasma cells. These features were ameliorated by steroid therapy, suggesting that the liver is concurrently affected in AIP, and that liver biopsies can provide significant information in the clinical evaluation and diagnosis of AIP.

Preferential X chromosome loss but random inactivation characterize primary biliary cirrhosis

Recent work has demonstrated enhanced X monosomy in women with primary biliary cirrhosis (PBC) as well as two other female-predominant autoimmune diseases, systemic sclerosis and autoimmune thyroid disease. To further our understanding of these events, we have investigated the mechanisms of X chromosome loss and X chromosome inactivation (XCI) in 166 women with PBC and 226 rigorously age-matched healthy and liver disease controls. X chromosome analysis and determination of loss pattern was performed by quantitative fluorescent polymerase chain reaction (QF-PCR) with 4 X-linked short tandem repeats. Further definition of the XCI was based on analysis of methylation-sensitive restriction sites. Importantly, in PBC the X chromosome loss occurs not only more frequently but also in a preferential fashion. This observation supports our thesis that the enhanced X monosomy involves only one parentally derived chromosome and is not secondary to a constitutive non random pattern of XCI. In fact, in the presence of monosomy, the lost X chromosome is necessarily the inactive homologue.

CONCLUSION

The finding that the X chromosome loss is preferential suggests the critical involvement of X chromosome gene products in the female predisposition to PBC and also emphasizes the need to determine the parental origin of the maintained chromosome to investigate the role of imprinting.

Prolactin stimulates the proliferation of normal female cholangiocytes by differential regulation of Ca2+-dependent PKC isoforms

Background

Prolactin promotes proliferation of several cells. Prolactin receptor exists as two isoforms: long and short, which activate different transduction pathways including the Ca²⁺-dependent PKC-signaling. No information exists on the role of prolactin in the regulation of the growth of female cholangiocytes. The rationale for using cholangiocytes from female rats is based on the fact that women are preferentially affected by specific cholangiopathies including primary biliary cirrhosis. We propose to evaluate the role and mechanisms of action by which prolactin regulates the growth of female cholangiocytes.

Results

Normal cholangiocytes express both isoforms (long and short) of prolactin receptors, whose expression increased following BDL. The administration of prolactin to normal female rats increased cholangiocyte proliferation. In purified normal female cholangiocytes, prolactin stimulated cholangiocyte proliferation, which was associated with increased [Ca²⁺]_i levels and PKCβ-I phosphorylation but decreased PKCα phosphorylation. Administration of an anti-prolactin antibody to BDL female rats decreased cholangiocyte proliferation. Normal female cholangiocytes express and secrete prolactin, which was increased in BDL rats. The data show that prolactin stimulates normal cholangiocyte growth by an autocrine mechanism involving phosphorylation of PKCβ-I and dephosphorylation of PKCα.

Conclusion

We suggest that in female rats: (i) prolactin has a trophic effect on the growth of normal cholangiocytes by phosphorylation of PKCβ-I and dephosphorylation of PKCα; and (iii) cholangiocytes express and secrete prolactin, which by an autocrine mechanism participate in regulation of cholangiocyte proliferation. Prolactin may be an important therapeutic approach for the management of cholangiopathies affecting female patients.

The biology of NKT cells

Recognized more than a decade ago, NKT cells differentiate from mainstream thymic precursors through instructive signals emanating during TCR engagement by CD1d-expressing cortical thymocytes. Their semi-invariant alphabeta TCRs recognize isoglobotrihexosylceramide, a mammalian glycosphingolipid, as well as microbial alpha-glycuronylceramides found in the cell wall of Gram-negative, lipopolysaccharide-negative bacteria. This dual recognition of self and microbial ligands underlies innate-like antimicrobial functions mediated by CD40L induction and massive Th1 and Th2 cytokine and chemokine release. Through reciprocal activation of NKT cells and dendritic cells, synthetic NKT ligands constitute promising new vaccine adjuvants. NKT cells also regulate a range of immunopathological conditions, but the mechanisms and the ligands involved remain unknown. NKT cell biology has emerged as a new field of research at the frontier between innate and adaptive immunity, providing a powerful model to study fundamental aspects of the cell and structural biology of glycolipid trafficking, processing, and recognition.

Cytotoxic T-lymphocyte-associated antigen-4 single nucleotide polymorphisms and haplotypes in primary biliary cirrhosis

BACKGROUND & AIMS

Twin and family studies suggest that there is a significant heritable component to primary biliary cirrhosis (PBC). Selected cytotoxic T-lymphocyte-associated antigen-4 (CTLA4) gene polymorphisms have been proposed as nonspecific determinants of disease risk in a variety of autoimmune diseases, including PBC. However, there has been considerable debate over the validity of these associations and the precise location of the disease-promoting polymorphism.

METHODS

We investigated 6 single-nucleotide polymorphisms in the CTLA4 gene in a total of 327 PBC patients and 391 healthy controls: 247 patients and 292 controls from the United Kingdom and a further 80 patients and 99 controls from northern Italy.

RESULTS

The previously reported association with CTLA4 A+49G was not replicated in the Italian series, and there were no significant differences in the distribution of any of the 6 polymorphisms comparing allele, genotype, or haplotype distribution in patients vs healthy controls in the UK series. Furthermore, there were no significant associations with the clinical variables of histologic stage, portal hypertension, or Mayo score. However, when PBC-40 Fatigue Domain scores were considered, a number of significant trends were noted, but none were significant after correction for multiple testing. Thus, fatigue scores were higher in those with the CTLA4 -319 T allele (P < .05, p corrected not significant) and in those with the CTLA4 +49 AA genotype (P < .05, pc not significant).

CONCLUSIONS

Contrary to previous reports the CTLA4 gene is not a major risk factor for PBC, nor is it a major determinant of disease progression.

Overexpression of gamma-glutamyltransferase in transgenic mice accelerates bone resorption and causes osteoporosis

We previously identified gamma-glutamyltransferase (GGT) by expression cloning as a factor inducing osteoclast formation in vitro. To examine its pathogenic role in vivo, we generated transgenic mice that overexpressed GGT in a tissue-specific manner utilizing the Cre-loxP recombination system. Systemic as well as local production of GGT accelerated osteoclast development and bone resorption in vivo by increasing the sensitivity of bone marrow macrophages to receptor activator of nuclear factor-kappaB ligand, an essential cytokine for osteoclastogenesis. Mutated GGT devoid of enzyme activity was as potent as the wild-type molecule in inducing osteoclast formation, suggesting that GGT acts not as an enzyme but as a cytokine. Recombinant GGT protein increased receptor activator of nuclear factor-kappaB ligand expression in marrow stromal cells and also stimulated osteoclastogenesis from bone marrow macrophages at lower concentrations. Thus, GGT is implicated as being involved in diseases characterized by accelerated osteoclast development and bone destruction and provides a new target for therapeutic intervention.

Autoimmune cholangitis in NOD.c3c4 mice is associated with cholangiocyte-specific Fas antigen deficiency

A major handicap in understanding the pathogenesis of autoimmune cholangitis has been the absence of an informative mouse model. Recently, autoimmune cholangitis, with several features similar to PBC, has been described in NOD.c3c4 mice, including anti-mitochondrial antibodies, lymphocytic portal tract infiltrates, biliary destruction and the adoptive transfer of disease to naïve recipients using liver-derived lymphocytes. A unique feature, and a characteristic quite distinct from human PBC, is the presence of bile cyst formation. We have addressed the issue of cysts in NOD.c3c4 mice by performing comprehensive microarray analysis using cholangiocytes from NOD.c3c4 mice compared to NOD controls. Several key differences in gene expression were noted in NOD.c3c4 cholangiocytes. First, there was consistent impairment in the expression of Fas antigen (CD95). Second, cholangiocytes were PCNA positive but TUNEL negative, suggesting an absence of apoptosis despite abnormal proliferation. In conclusion, we propose that autoimmune cholangitis develops in NOD.c3c4 mice secondary to impaired biliary cell apoptosis with exposure of mitochondrial antigens, loss of tolerance and subsequent development of multi-lineage anti-mitochondrial responses.

Characterization of overlap syndrome between primary biliary cirrhosis and autoimmune hepatitis according to antimitochondrial antibodies status

AIMS

Codification of variant forms between Primary Biliary Cirrhosis (PBC) and Autoimmune Hepatitis (AIH) has not been definitively standardized. The aim of this study was to compare among 102 consecutive patients, 2 subsets of overlap syndrome (OS, N=21) with and without antimitochondrial antibody (AMA) to two groups of patients with typical PBC (N=43) or AIH (N=38).

METHODS

OS was defined by the presence in the same patient of at least 2 of 3 accepted criteria of PBC and AIH. Twelve patients with OS were AMA negative and 9 were AMA positive.

RESULTS

A lower level of alanine transaminase (139+/-48 vs 269+/-154 IU/L, P<0.05) and a trend towards a higher level of alkaline phosphatase or gamma-glutamyl transpeptidase was observed in OS without AMA than in OS with AMA (693+/-200 vs 544+/-124 IU/L; 370+/-66 vs 241+/-77 IU/L, respectively). All AMA-negative patients with OS had antinuclear and/or anti-smooth muscle antibodies. OS without AMA differed from those with AMA in that they had more severe bile duct damage including destructive cholangitis (P<0.05), ductopenia (P<0.05), ductular hyperplasia (P<0.05) and a higher METAVIR fibrosis score (2.5+/-0.3 vs 1.3+/-0.3, P<0.05). The response to therapy was not different between PBC, AIH and OS.

CONCLUSIONS

According to the presence of AMA, 2 homogeneous subgroups of patients with overlap syndrome between PBC and AIH may be identified. AMA status affects clinical presentation and liver disease severity of OS.

Biliary epithelial-mesenchymal transition in posttransplantation recurrence of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) recurs in the allograft after liver transplantation. Study of early tissue changes in the time-course of disease recurrence provides a unique insight into the initial stages of the disease process, which, in nontransplant patients, occurs long before clinical presentation. We describe a patient who developed classical clinical, biochemical, immunological, and histological features of PBC within 9 months after transplantation. Use of tissue from this patient before and during the development of PBC allowed us to identify biliary epithelial cell (BEC) epithelial-mesenchymal transition (EMT) as a key pathogenetic process. BEC expression of S100A4 (an early fibroblast lineage marker established as a robust marker of EMT), vimentin, and pSmad 2/3 [a marker of transforming growth factor beta (TGF-beta) pathway signaling] were identified immunohistochemically in most BECs in liver tissue from this patient at the point of diagnosis of recurrent disease. BEC expression of S100A4 and pSmad 2/3 was seen as early as 24 days after orthotopic liver transplantation (OLT), although no other features of recurrent PBC were present at this time.

CONCLUSION

S100A4, vimentin, and pSmad 2/3 expression in early recurrent PBC after OLT suggests that BEC EMT is occurring (potentially explaining BEC loss) and that this process is driven by TGF-beta. S100A4 expression by BEC appears to occur before the development of any other features of recurrent PBC, suggesting that EMT may be an initiating event.

The X and why of xenobiotics in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic autoimmune liver disease characterized by inflammation and destruction of intrahepatic biliary epithelial cells, ultimately leading to liver failure. The serological hallmark of PBC is the presence of high-titer antimitochondrial antibodies (AMA) against the inner lipoyl domain of E2 subunits of 2-oxo-acid dehydrogenase complexes, in particular the E2 component of the pyruvate dehydrogenase complex (PDC-E2). The initiating events triggering the autoimmune response are not yet identified but the hypothesis of molecular mimicry is a widely proposed mechanism for the development of autoimmunity in PBC. Several candidates, including bacteria and viruses, have been suggested as causative agents, but also environmental factors, such as chemical xenobiotics, have been implicated in the pathogenesis of primary biliary cirrhosis. In this review, we will discuss our current knowledge of the immunoreactivity of xenobiotically modified PDC peptide antigens. In addition, we will provide a working hypothesis how xenobiotic modification of antigens might occur that ultimately leads to the breaking of self-tolerance and the induction of PBC.

Systematic review of controlled clinical trials on the use of ursodeoxycholic acid for the prevention of hepatic veno-occlusive disease in hematopoietic stem cell transplantation

Hepatic veno-occlusive disease (HVOD) is a serious life-threatening complication of hematopoietic stem cell transplantation (HSCT). Currently, there is no optimal therapeutic strategy and preventive measures are ill-defined. Ursodeoxycholic acid (UA) is well-tolerated oral medication that has been associated with possible benefit as a prophylactic agent. We sought to summarize and quantify the clinical effects of prophylactic UA in the context of HSCT. We undertook a systematic review of studies addressing the use of UA as monotherapy or in combination with other agents in patients undergoing HSCT. The Search Strategy included MEDLINE (1966 to fourth week of March 2006), EMBASE (1980 to fourth week of March 2006), all EBM Reviews (fourth quarter of 2005), Ovid Healthstar (1966 to fourth week of March 2006), and Google Scholar on March 20, 2006. Six studies, 4 randomized clinical trials and 2 historically controlled studies, representing 824 patients were included in the review. Three randomized clinical trials comparing prophylactic UA with no treatment demonstrated reduced proportion of HVOD (relative risk [RR], 0.34; 95% confidence interval [CI], 0.17-0.66). When the analysis was limited to higher-quality studies, the beneficial effect of UA remained significant (RR, 0.36; 95% CI, 0.15-0.90). Transplant-related mortality was also reduced with the prophylactic use of UA (RR, 0.58; 95% CI, 0.35-0.95). UA did not significantly attenuate the outcomes of acute graft-versus-host disease (RR, 0.76; 95% CI, 0.53-1.09), relapse (RR, 0.77; 95% CI, 0.46-1.31), or overall survival (RR, 1.22; 95 % CI, 0.96-1.54). UA appears effective for HVOD prophylaxis in patients undergoing HSCT and should be considered as a prevention strategy by HSCT centers to reduce HVOD.

Late-onset sarcoidosis after liver transplantation for primary biliary cirrhosis

Primary biliary cirrhosis (PBC) and systemic sarcoidosis are granulomatous diseases of unknown etiology whose hepatic manifestations may infrequently be imitative of one another. Described herein is the first reported case in the medical literature of systemic sarcoidosis developing after liver transplantation for PBC. The presented patient, who suffered from typical clinical, laboratory, and pathologic manifestations of PBC, developed decompensated liver cirrhosis within a course of 8 years, necessitating orthotopic liver transplantation. A year and a half after transplantation, the patient developed diffuse, biopsy-proven, dermatologic and pulmonary manifestations of systemic sarcoidosis, which promptly responded to corticosteroid treatment. In retrospect, the patient's longstanding liver disease was probably caused by an unrecognizable, isolated hepatic form of sarcoidosis or an overlap between PBC and sarcoidosis. This patient illustrates the complexity that may be rarely encountered in differentiating between PBC and hepatic sarcoidosis. Discussed are the clinical, laboratory, and pathologic overlaps between hepatic sarcoidosis and PBC, and clues that may aid in the diagnosis and differentiation between the 2 disorders. Hepatologists and liver transplantation specialists should be aware of the rare possibility of hepatic sarcoidosis imitating PBC, and exacerbating systemically after liver transplantation.

Primary biliary cirrhosis: what we know and what we want to know about human PBC and spontaneous PBC mouse models

Human autoimmune cholangiopathy comprises several intractable liver diseases that ultimately lead to hepatic failure. Primary biliary cirrhosis (PBC), allograft rejection, graft versus host diseases, and, possibly, primary sclerosing cholangitis are representative of immune-mediated cholangiopathies. Among them, PBC is the best-investigated human autoimmune cholangiopathy. The immunological approach to PBC has provided much critical information regarding its pathogenesis. The breakdown of self-tolerance in both B cells and T cells toward E2 components of the pyruvate dehydrogenase complex is evident. However, a number of questions regarding its etiology are unclear, in particular, the mechanisms involved in the selectivity of cholangiocyte destruction. In this brief review, we discuss what we know and we do not know regarding the pathogenesis of PBC.

A sensitive bead assay for antimitochondrial antibodies: Chipping away at AMA-negative primary biliary cirrhosis

The antimitochondrial response in primary biliary cirrhosis (PBC) is the most highly directed and specific self-reacting antibody in human immunopathology. Originally, antimitochondrial antibodies (AMAs) were detected by indirect immunofluorescence (IIF) and found in approximately 90% of well-documented patients with PBC. The introduction of recombinant autoantigens and the use of immunoblotting have increased the sensitivity and specificity of AMAs, and they are now considered positive in approximately 95% of patients with PBC. Clearly, accurate autoantibody detection represents one of the fundamental requirements for reliable diagnostics in autoimmunity. To address the 5% of AMA-negative patients with PBC, we have generated and validated a bead assay for the detection of AMA. We enrolled 120 patients with PBC, including a non-random group of 30 rigorously proven AMA-negative patients, 50 healthy subjects, and 74 controls with autoimmune diseases (18 with primary sclerosing cholangitis, 16 with autoimmune hepatitis, and 40 with systemic lupus erythematosus). Individual bead assays were done with the three mitochondrial autoantigens, PDC-E2, BCOADC-E2, and OGDC-E2. As expected, 90 of 90 previously known AMA-positive patients remained positive with this assay but, interestingly, 20% of the rigorously defined AMA-negative patient group had antibodies to one or more of the mitochondrial autoantigens. Furthermore, 100% of these newly detected AMA-positive patients were anti-nuclear antibody (ANA) positive.

CONCLUSION

The development of this assay reflects the potential for automated detection with rapid and reliable assaying and further highlights the diminished number of truly AMA-negative PBC patients.

Pure white cell aplasia: report of the first case associated with primary biliary cirrhosis

Pure white cell aplasia (PWCA) is a rare hematologic disorder characterized by agranulocytosis, a lack of virtually all neutrophil-lineage cells (from neutrophils to myeloblasts) in the bone marrow, and normal erythropoiesis and megakaryocy-topoiesis. We report the first case of PWCA that developed in a patient with primary biliary cirrhosis (PBC). An 83-year-old woman, who had had an elevated serum alkaline phosphatase level and shown positivity for serum antimitochondrial antibodies for 10 years, was referred to us because of a perianal abscess. She had severe neutropenia, and her bone marrow showed typical findings of PWCA. Although methylprednisolone pulse therapy induced complete neutrophil recovery, this effect was transient. She died of infection, and the autopsy confirmed the diagnosis of PBC. In vitro investigations showed that factors inhibitory to normal CD34 cell-derived granulopoiesis were present in the patient's serum.