An exploratory population-based case-control study of primary biliary cirrhosis

Recent advances in the epidemiology of primary biliary cirrhosis

Since initial reports in the mid-1970s provided epidemiology data on primary biliary cirrhosis (PBC), many studies have characterized the variable frequency of this disease in diverse populations worldwide and sought to identify associated risk factors. Recent research confirms earlier work suggesting that the incidence and prevalence of PBC are on the rise, although geographic variation persists. Analysis of familial and geographic clustering supports the hypothesis that development and progression of the disease hinge on a complex interplay between genetic and environmental risk factors. International clinical data systems are needed to advance PBC epidemiologic research. Given this complexity, international clinical data systems are needed to advance PBC epidemiologic research.

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.

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.

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

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

Mapping of a disease susceptibility locus in the HLA region for Primary Biliary Cirrhosis in Japan

AIMS

Primary biliary cirrhosis (PBC) is a chronic progressive cholestatic disease of unknown pathogenesis. However, several reports have demonstrated the involvement of genetic backgrounds in this syndrome. The aim of this study is to examine the genetic disequilibrium in the HLA region in Japanese patients using six microsatellite markers.

METHODS

Genomic DNAs were obtained from 73 patients with PBC (patient cohort) and 186 healthy volunteers (control cohort). Genetic polymorphisms at six microsatellite markers (D6S1568, DQ.CAR, D6S273, TNF-d, C1-2-A, C3-2-11) were determined using fluorescence-labeled polymerase chain reaction (PCR) genetic analyzer. Allele frequencies were estimated by direct counting and the genotypic differentiation test was performed by the Markov chain method using Genepop software.

RESULTS

Among these six microsatellite markers, four markers in the patients significantly (P < 0.05) deviated from the Hardy-Weinberg equilibrium: DQ.CAR (P = 0.0278), D6S273 (P = 0.0168), TNF-d (P = 0.0089) and C1-2-A (P = 0.0005). Genotypic differentiation test between the patients and controls demonstrated that DQ.CAR (P = 0.0111), TNF-d (P = 0.0051) and C1-2-A (P = 0.0371) were significant. Finally, allelic association test revealed before correction for multiple testing demonstrated allele125 of TNF-d (P = 0.00065, Pc = 0.0052) and allele246 of C1-2-A (P = 0.0026 Pc = 0.033) had significant association after Bonferroni's correction.

CONCLUSION

Disequilibrium mapping using microsatellite markers was a useful method to narrow a disease susceptibility locus. The possible susceptibility gene in the HLA region is thought to be localized around or in the TNF gene. Further studies seem feasible using more closely distributed microsatellite markers or single nucleotide polymorphisms (SNPs) to narrow the susceptibility locus in PBC in Japanese populations.

Smoking and increased severity of hepatic fibrosis in primary biliary cirrhosis: A cross validated retrospective assessment

An epidemiological association between cigarette smoking and primary biliary cirrhosis (PBC) has been demonstrated. Our aim was to determine the relationship between smoking and severity of liver fibrosis at presentation in patients with PBC. All patients with PBC seen at the three major teaching hospitals of Case Western Reserve University between October 1998 and December 2005 were identified. Data obtained at the time of the first evaluation leading to the PBC diagnosis on 97 patients were collected. The cumulative number of cigarette packs smoked per year (pack-years) was calculated. Advanced histological disease was defined as Ludwig stages 3 or 4. Analyses were performed to determine associations between advanced histological disease, smoking and other variables related to liver fibrosis. Smoking history was more common (P = .0008) in patients with advanced histological disease at presentation compared to those with early disease. Among smokers, mean lifetime tobacco consumption was higher (P = .04) in cases with advanced histological disease at presentation (30 pack-years) compared to cases with early disease (17 pack-years). Logistic regression demonstrated a significant association between a lifetime tobacco consumption of > or =10 pack-years and advanced histological disease at presentation (OR = 13.3). The association remained significant after adjusting for age, gender, and alcohol intake. The validity of these results was corroborated by cross-validation in an independent confirmatory set of 172 patients with PBC. In conclusion, smoking may accelerate the progression of PBC. This could be induced by exposure to chemicals in cigarette smoke.

Lack of association between appendectomy and primary biliary cirrhosis

OBJECTIVE

In view of the possible implication of various environmental factors in the pathogenesis of primary biliary cirrhosis (PBC), the role of appendectomy in patients with PBC and other chronic liver diseases from Central Greece was investigated.

MATERIAL AND METHODS

The medical files of 68 patients with PBC and gender- and age-matched controls with chronic hepatitis C virus (HCV) infection (n=65) and chronic hepatitis B virus (HBV) infection (n=67) were reviewed for the history and time of appendectomy.

RESULTS

Nineteen of 68 (27.9%) PBC patients, 32 of 65 (49.2%) patients with chronic HCV infection and 22 of 67 (32.8%) patients with chronic HBV infection had a history of appendectomy. There was a significant higher frequency of appendectomy in patients with chronic hepatitis C (p = 0.012, chi(2) test) compared to patients with PBC. There were no significant differences in the clinical and histological characteristics of PBC patients with or without a history of appendectomy.

CONCLUSION

In this case-control study we were unable to provide evidence of an association between primary biliary cirrhosis and the occurrence of appendectomy.

Pathogenesis of primary biliary cirrhosis: A unifying model

Primary biliary cirrhosis (PBC) is a disease of unknown etiology leading to progressive destruction of small intrahepatic bile ducts and eventually to liver cirrhosis and failure. It is characterised by female predominance and serum auto-antibodies to mitochondrial antigens targeting the E2 components of the 2-oxoacid dehydrogenase complex. Although they are associated with disease pathogenesis, no concrete evidence has been presented so far. Epidemiological data indicate that a geographical clustering of cases and possible environmental factors are implicated in pathogenesis. A number of genetic factors play a role in determining disease susceptibility or progression, although no definitive conclusion has been reached so far. A key factor to immune pathogenesis is considered to be the breakdown of immune tolerance, either through molecular mimicry or through the so called determinant density model. In this review, the available data regarding the pathogenesis of primary biliary cirrhosis are described and discussed. A new unifying hypothesis based on early endothelin overproduction in primary biliary cirrhosis (PBC) is presented and discussed.

A case of primary biliary cirrhosis complicated by Behçet’s disease and palmoplantar pustulosis

A 46-year-old woman was diagnosed with palmoplantar pustulosis (PPP) at the Department of Dermatology, Fukushima Medical University Hospital in 2000, and was treated with ointment. However, because liver dysfunction developed in 2003, she was referred to our department, where primary biliary cirrhosis (PBC) was also diagnosed on the basis of clinical findings. One year later, at the age of 49, she developed manifestations of Behçet’s disease (BD), including erythema nodosum in the lower extremities. Because she had a history of uveitis, recurrent oral ulceration was present, and the HLA typing was positive for B51, BD was additionally diagnosed. Liver function normalized within three months of the start of treatment with ursodesoxycholic acid (UDCA). This is the first case of PBC associated with BD and PPP.

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.

Increased prevalence of primary biliary cirrhosis near Superfund toxic waste sites

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are uncommon liver diseases of unknown etiology. Reported clustering of PBC cases may be due to environmental factors. Individuals with PBC have a high prevalence of thyroid disease and thyroid disease is reportedly more prevalent near Superfund toxic waste sites (SFS). The objective of this study was to examine the prevalence and potential clustering of individuals with PBC and PSC near SFS. De-identified clinical and demographic data were used to determine the observed prevalence for each New York City zip code (n = 174) and borough (n = 5) of patients with PBC (PBC-OLT) or PSC (PSC-OLT) who were listed for liver transplantation. The expected prevalence was calculated using Organ Procurement and Transfer Network (OPTN) and U.S. Census data. Both PBC-OLT patients and patients not listed for liver transplantation (PBC-MSSM) were included in the cluster analysis. Prevalence ratios of PBC-OLT and PSC-OLT cases were compared for each zip code and for each borough with regard to the proximity or density of SFS, respectively. SaTScan software was used to identify clusters of PBC-OLT cases and PBC-MSSM cases. Prevalence ratio of PBC-OLT, not PSC-OLT, was significantly higher in zip codes containing or adjacent to SFS (1.225 vs. 0.670, respectively, P = .025). The borough of Staten Island had the highest prevalence ratio of PBC-OLT cases and density of SFS. Significant clusters of both PBC-OLT and PBC-MSSM were identified surrounding SFS. In conclusion, toxin exposure may be a risk factor influencing the clustering of PBC cases.

Reduced heart rate variability and baroreflex sensitivity in primary biliary cirrhosis

BACKGROUND

Standardized mortality ratio for primary biliary cirrhosis (PBC) is 2.87. Even after accounting for liver and cancer-related deaths there is an unexplained excess mortality associated with PBC. We have assessed heart rate variability (HRV) and baroreflex sensitivity (BRS) risk factors associated with cardiovascular mortality, in 57 PBC patients and age- and sex-matched normal controls.

METHODS

HRV and BRS were measured non-invasively in subjects and controls. Beat to beat RR interval and 'Portapres' blood pressure data were processed using power spectral analysis. Power was calculated in very low frequency (VLF), low-frequency (LF) and high-frequency (HF) bands according to international guidelines. BRS (alpha) was computed using cross-spectrum analysis. Patients also underwent fatigue severity assessment using a measure validated for use in PBC.

RESULTS

PBC patients had significantly lower total HRV compared with controls (P=0.02), with the reduction occurring predominantly in the LF domain (P=0.03). BRS was also significantly reduced compared with controls (P=0.02). There were no significant differences in HRV or BRS between cirrhotic and non-cirrhotic patients. Within the PBC patient group HRV was significantly lower in fatigued than in non-fatigued patients (P<0.05).

CONCLUSION

Abnormalities of HRV and BRS in PBC are not specific to advanced disease but are associated with fatigue severity. Abnormalities could be associated with increased risk of sudden cardiac death, potentially contributing to the excess mortality seen in PBC.

Effect of Cigarette Smoke on Autoimmunity in Murine and Human Systemic Lupus Erythematosus

Several studies have found that smoking cigarettes is a risk factor for systemic lupus erythematosus (SLE). To examine this issue in a mouse model, we subjected pre-autoimmune MRL-lpr/lpr mice for 4 weeks to cigarette smoke to provide standardized smoke effluents equivalent to moderate or to heavy smoking habits for people. The spontaneous production of IgG anti-chromatin but not IgM anti-chromatin, anti-denatured DNA, or rheumatoid factor antibodies was lower in mice exposed to 250 mg/m3 particulates from mainstream smoke, and this suppression of autoimmunity was sustained for 8 weeks (p < 0.02). In contrast to control mice anti-chromatin activity in smoke-exposed mice began to increase in 16-week-old mice, reaching levels at 6 months that were two- to three-fold higher than controls for IgG (p < 0.03) and 10-fold higher for IgM (p < 0.001). There was no significant effect on total IgG or IgM. In newly diagnosed SLE patients, smoking was negatively correlated with IgG anti-DNA antibodies (p < 0.03). However, of nine patients who discontinued smoking prior to diagnosis, eight had elevated IgG anti-DNA compared to 29/79 never smokers and 9/31 smokers (p < 0.01 compared to former smokers). Inhaled cigarette smoke appears to have a long-lasting immunosuppressive effect on T-cell-dependent autoimmune responses, although autoantibodies increase to supra-elevated levels after the suppressive effect has abated.

Autoimmune cholestatic liver disease in people with coeliac disease: a population-based study of their association

BACKGROUND

Population data supporting an association between the autoimmune cholestatic liver diseases, primary biliary cirrhosis and primary sclerosing cholangitis and coeliac disease, is limited and at times contradictory.

AIM

To explore the relationship between coeliac disease and both primary biliary cirrhosis and primary sclerosing cholangitis within the General Practice Research Database, a UK-based longitudinal primary care database.

METHODS

We identified 4732 people with diagnosed coeliac disease and 23 620 age- and sex-matched controls within the General Practice Research Database. We calculated the prevalence of primary biliary cirrhosis and primary sclerosing cholangitis for both the coeliac disease and control group.

RESULTS

There was a higher prevalence of primary biliary cirrhosis in adults with coeliac disease, compared with controls [0.17% vs. 0.05%, odds ratio 3.63 (95% confidence interval: 1.46-9.04)]. Primary sclerosing cholangitis was also more common in the coeliac disease group [0.04% vs. 0%, fishers exact test (P = 0.03)].

CONCLUSIONS

There was a threefold or greater increase in risk of both primary biliary cirrhosis and primary sclerosing cholangitis in people with coeliac disease compared with the general population. The association with primary biliary cirrhosis was weaker than in some reports and it is difficult on the basis of this study to justify screening patients with coeliac disease for either primary biliary cirrhosis or primary sclerosing cholangitis.

Fracture risk of women with primary biliary cirrhosis: no increase compared with general population controls

AIM

Patients with primary biliary cirrhosis may be at increased risk of osteoporosis but to what extent this is reflected in an increased fracture risk is unknown. We have enquired about the fracture experience of female primary biliary cirrhosis patients compared with sex- and age-matched controls.

METHODS

Patients aged 30-75 with primary biliary cirrhosis and age-matched controls were sent a postal questionnaire asking about their fracture history and details of risk factors for osteoporosis.

RESULTS

85 eligible patients with primary biliary cirrhosis and 116 controls responded. Forty-one per cent of patients with primary biliary cirrhosis and 30% of controls reported ever having had a fracture odds ratio 1.5 (95% confidence interval: 0.80-2.89). Twenty-eight per cent of primary biliary cirrhosis patients and 23.3% of controls reported a fracture after the age of 30, odds ratio 1.2 (95% confidence interval: 0.57-2.56), and 14.1% of primary biliary cirrhosis patients and 12.1% of controls reported a low impact fracture of the long bones or of the vertebrae odds ratio 1.0 (95% confidence interval: 0.31-2.68).

CONCLUSIONS

No overall increased fracture risk in patients with primary biliary cirrhosis was observed. As a group, unselected patients with primary biliary cirrhosis do not represent a population at particularly high risk of osteoporotic fracture and thus targeting them for osteoporosis screening and treatment is not justified. Further work investigating subgroups of patients with primary biliary cirrhosis at potentially high risk of osteoporosis, such as those with advanced disease or severe cholestasis is required.

Patterns of autoimmunity in primary biliary cirrhosis patients and their families: a population-based cohort study

BACKGROUND

Primary biliary cirrhosis (PBC) is a chronic liver disease with autoimmune features but uncertain aetiology. Increased risk of PBC among relatives of patients may reflect common environmental factors, or inherited immunogenetic susceptibility. Associations between PBC and other autoimmune diseases have been reported, but their true extent and pattern is unknown.

AIM

To examine the prevalence and association patterns of autoimmune disease in a representative group of PBC patients.

DESIGN

Clinical cohort study.

METHODS

We clinically assessed members of a geographically-based PBC patient cohort (n = 160) for the presence of additional autoimmune disease, using established specific diagnostic criteria.

RESULTS

Some 53% of patients had at least one additional autoimmune condition, and 63% had serum autoantibodies other than AMA or ANA. AMA+ patients had a significantly lower prevalence of additional autoimmunity than AMA- patients (49% vs. 79%; p < 0.01). The greatest relative increase in disease prevalence was for scleroderma (8% of patients). Autoimmune disease was present in 14% of first-degree relatives.

DISCUSSION

PBC patients and their families have a wide susceptibility to autoimmunity. This observation supports an autoimmune aetiology and suggests that the genetic basis of PBC is likely to be expressed, at least in part, through factors controlling immune tolerance in general.

Cigarette smoking and the risk of systemic lupus erythematosus: a meta-analysis

OBJECTIVE

Existing studies present conflicting evidence for the role of cigarette smoking as a risk factor in the development of systemic lupus erythematosus (SLE). We performed an extensive search of the medical literature for all studies examining this relationship, and performed a meta-analysis to arrive at a more precise estimate of effect.

METHODS

We performed a computerized literature search for all studies (in all languages), using Medline and EMBASE (1966 to present) and the Cochrane Collaboration database, and completed hand searches of relevant bibliographies and abstracts of conference proceedings. Several investigators systematically extracted data from the relevant studies. Unpublished data were obtained from the author of one abstract. Studies were examined in aggregate for heterogeneity and publication bias. The relationships of current smoking and past smoking (prior to the onset of SLE) to development of SLE were analyzed separately.

RESULTS

Fifty-two studies were identified and chosen for detailed review. Of these, 9 (7 case-control and 2 cohort studies) were appropriate for inclusion in our meta-analyses. For current smokers compared with nonsmokers, the odds ratio (OR) for development of SLE was significantly elevated (OR 1.50, 95% confidence interval [95% CI] 1.09-2.08). Former smokers, compared with nonsmokers, did not demonstrate an increased risk of SLE (OR 0.98, 95% CI 0.75-1.27). Several subgroups were also analyzed.

CONCLUSION

Our meta-analysis of the 7 existing case-control and 2 cohort studies revealed a small but statistically significant association between current smoking and development of SLE. However, no association between past smoking and development of SLE was observed.

Epidemiology and pathogenesis of primary biliary cirrhosis

Primary biliary cirrhosis is an autoimmune disease of unknown etiology leading to progressive destruction of small intrahepatic bile ducts and eventually to liver cirrhosis and failure. It is characterized by female predominance (with most cases observed between the ages of 40 and 60) and serum autoantibodies to mitochondrial antigens as highly specific hallmarks. Epidemiologic data indicate a variable incidence and prevalence of the disease. A number of genetic factors have been indicated as playing a role in determining disease susceptibility or progression, although no definitive conclusion has been reached so far. However, as suggested by some epidemiologic observations, a number of environmental factors, including molecular mimicry by either microorganisms or xenobiotics, have also been proposed. A hypothesis gaining support is that environmental factors may trigger disease in genetically predisposed individuals. In this review, the available data regarding the epidemiology and pathogenesis of primary biliary cirrhosis will be described and discussed.

The epidemiology of primary biliary cirrhosis

Over the last 30 years, many studies have reported on the epidemiology of PBC. Substantial increases in prevalence were noted in the majority of studies examining longitudinal data, and several have reported increases in the incidence of PBC. Furthermore, although it is difficult to compare studies directly, as methods of case ascertainment have greatly improved over this period, there has been a definite trend toward increasing prevalence (and also possibly incidence) across studies. Together, these data strongly suggest that in many countries, the frequency with which PBC is diagnosed has increased considerably between 1980 and the present time. The reasons for this change may be complex. There may have been a true increase in the incidence of PBC, reflecting either increased exposure to a currently unknown environmental etiological agent or demographic changes with an increased elderly, at-risk population. The prevalence may have further increased due to increased survival of patients, either due to improved care or earlier diagnosis. Some of the apparent increase in PBC frequency may also be artifactual, however, resulting from increased use of diagnostic tests, particularly autoantibody screens. This may be due to increased availability of testing, increased clinician (or patient) awareness of PBC, increased use of testing in well-person screening, or increased investigation of ill-defined symptoms. Furthermore, there may also have been an improvement in clinicians' ability to recognize PBC on the basis of the clinical picture (in one study, 37% of patients whose clinical results indicated a diagnosis of PBC were not recognized by the clinician caring for the patient at that time). The last factor alone suggests that all studies based only upon cases known to interested clinicians have probably substantially underestimated the prevalence of disease. Whatever the reason, the recognized epidemiology of PBC has dramatically changed over the past 30 years. It is now a frequent cause of liver morbidity, and patients with PBC are significant users of health resources, including liver transplantation. Large geographical variations in disease frequency, both between and within studies, tantalizingly suggest the presence of as-yet-unidentified risk factors. This should be further followed up with new analytical epidemiological studies. Only two case control studies have examined risk factors for PBC, and these have been either relatively small or used poorly defined and potentially biased experimental groups. These need repeating in new settings. We suggest that, as with other diseases, modern epidemiological instruments used in well-designed studies may provide important clues to the cause or causes of this disease.

Primary biliary cirrhosis: historical perspective

PBC is an old disease first described in 1851. It's predilection for women and its association with other autoimmune diseases suggests an immune based pathogenesis, but epidemiologic studies indicate that genetic and environmental factors play a role in the pathogenesis of PBC. The serologic hallmark for PBC, namely the antimitochondrial antibody, was first identified in 1965 and remains the most sensitive and specific hallmark for this disease. When first described, primary biliary cirrhosis was universally fatal but asymptomatic cases now represent more than 60% of cases diagnosed, less than half of whom will die of their liver disease. No specific therapy that effectively stops or reverses disease progression has been identified, thus it behoves investigators to aggressively pursue identification of the etiology of PBC.

Primary biliary cirrhosis

Primary biliary cirrhosis is a chronic cholestatic liver disease of adults. This disorder is characterised histologically by chronic non-suppurative destruction of interlobular bile ducts leading to advanced fibrosis, cirrhosis, and liver failure. The precise aetiopathogenesis of primary biliary cirrhosis remains unknown, although dysregulation of the immune system and genetic susceptibility both seem to be important. Affected patients are typically middle-aged women with abnormal serum concentrations of alkaline phosphatase. Presence of antimitochondrial antibody in serum is almost diagnostic of the disorder. Identification of primary biliary cirrhosis is important, because effective treatment with ursodeoxycholic acid has been shown to halt disease progression and improve survival without need for liver transplantation. However, therapeutic options for disease-related complications-including fatigue and metabolic bone disease-remain unavailable. Mathematical models have been developed that accurately predict the natural history of primary biliary cirrhosis in individuals. Despite advances in understanding of the disease, it remains one of the major indications for liver transplantation worldwide.

Survival and symptom progression in a geographically based cohort of patients with primary biliary cirrhosis: follow-up for up to 28 years

BACKGROUND & AIMS

Although several excellent studies have described the natural history of primary biliary cirrhosis, most were reported from tertiary referral centers. We examined the prognosis of primary biliary cirrhosis in a comprehensive geographically defined cohort.

METHODS

We followed up 770 primary biliary cirrhosis patients prevalent between January 1987 and December 1994 until death, transplantation, or censor on January 1, 2000, by interview and review of case notes and death certificates. Analysis of survival data was performed with Kaplan-Meier methods and Cox regression.

RESULTS

Median patient survival was 9.3 years from diagnosis. Patient age, alkaline phosphatase, albumin, and bilirubin at diagnosis independently predicted survival in Cox modeling. Prothrombin time and histologic stage did not independently affect survival. Observed survival was predicted well by this model and by the Mayo prognostic score (R2(M) = 0.37 and 0.18, respectively; R2(M) is a likelihood-based measure of the percentage information gain from the model due to covariates). Forty-two percent of deaths were caused by liver disease. Thirty-nine patients had liver transplantations by the censor date. Survival was much poorer than for an age- and sex-matched control population (standardized mortality ratio = 2.87 [1.73 excluding liver deaths]). The most common symptoms at diagnosis were pruritus (18.9%) and fatigue (21.0%). Twenty-six percent of patients developed liver failure by 10 years after diagnosis.

CONCLUSIONS

Although primary biliary cirrhosis is often now diagnosed at an early stage, the diagnosis still carries important prognostic implications. A significant proportion of patients develop liver failure, require transplantation, or die prematurely after this diagnosis.

Medical and economic impact of autoimmune hepatitis

AIH is a chronic liver disease that has been associated with hepatic failure and death in the absence of liver transplantation. As a result, AIH imparts significant medical and economic burdens on affected patients and health care delivery systems, respectively. The use of accepted methodologies for outcomes and health services research has identified emerging information on the epidemiology and natural history, HRQoL, and resource utilization for similar autoimmune chronic liver diseases such as PBC and PSC. Similar efforts are needed in AIH, and they are supported on the basis of existing data which suggest similar levels of disease burden compared to PBC and PSC. As a result, the ability to plan for disease management strategies in AIH that require the allocation of scarce resources will be feasible.

The association between gravidity and primary biliary cirrhosis

PURPOSE

Primary biliary cirrhosis is an autoimmune disease with female predominance that leads to liver failure. The goal of this study was to identify reproductive risk factors associated with this disease.

METHODS

We compared 182 cases of PBC with 225 age- and sex-matched friend controls to examine the role of reproductive factors. The survey instrument was developed using standardized questions obtained from the National Health and Nutrition Examination Survey (NHANES) III.

RESULTS

A total of 126/182 cases (69%) and 141/225 (62.6%) friend controls responded to the survey. More cases than controls reported ever having genitourinary infection [adjusted odds ratio (OR) = 2.12, 95% confidence interval (CI) 1.01, 4.42] among those without a personal or family history of autoimmune disease. The most notable finding was that cases reported significantly more pregnancies than controls (p = 0.008). The adjusted OR for each additional pregnancy among those without a personal or family history of autoimmune disease was 1.40 (95% CI 1.14, 1.7). More controls (24.4%) than cases (16.0%) were nulliparous. Cases reported having five or more children (16.0%) with double the frequency of controls (8.2%).

CONCLUSIONS

The association reported herein, between primary biliary cirrhosis and gravidity, is particularly significant because of the overwhelming female predominance.

Investigation of a mechanism for accelerated breakdown of immune tolerance to the primary biliary cirrhosis-associated autoantigen, pyruvate dehydrogenase complex

Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterized by autoreactive T- and B-cell responses to the highly conserved enzyme pyruvate dehydrogenase complex (PDC). In this study we have examined the breakdown of T-cell tolerance to self-PDC using a mouse model. Female SJL/J mice were sensitized intraperitoneally with foreign-PDC (bovine) and/or self-PDC (murine) in complete Freund's adjuvant, and serum, spleen, and liver tissue was taken 8 weeks later. Animals sensitized with foreign-PDC produced IgG antibodies that were reactive with both foreign and self-PDC, but splenic T cells from these animals only responded to stimulation with foreign PDC. Sensitization with self-PDC elicited neither antibodies nor reactive T cells. Significantly, cosensitization with mixed self-PDC and foreign-PDC resulted in a full breakdown of self-tolerance, with generation of both antibody and T-cell responses to self-PDC of the type seen exclusively in human PBC patients. Mild bile duct lesions deficient in CD8(+) T cells were seen 8 weeks after sensitization with either foreign or self-PDC. However, after sensitization with mixed self-PDC and foreign-PDC, these lesions were significantly larger and heavily infiltrated by CD8(+) T cells. Liver-infiltrating T cells derived from the self-PDC and foreign-PDC cosensitized but not from control animals showed reactivity with self-PDC, suggesting a possible role for autoreactive PDC-specific T-cell responses in the pathogenesis of the observed histologic changes. It is likely that B-cell cross-reactivity between foreign and self-PDC enhances the potential for breakdown of T-cell self-tolerance by allowing efficient presentation of self-antigens in the inoculum. This model may provide a useful system for investigating the etiology and treatment of PBC.

IgA antibodies to gliadin and coeliac disease in psoriatic arthritis

OBJECTIVES

To find out whether patients with psoriatic arthritis (PsoA) have an increased prevalence of antibodies to gliadin (AGA) and of coeliac disease.

METHODS

One hundred and fourteen PsoA patients with skin disease of 20+/-13 yr and joint disease of 11+/-10 yr duration answered a questionnaire concerning their medical history and underwent clinical examination, including radiology. Serum IgA AGA and IgG AGA, IgA antibodies to endomysium and immunoglobulins, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) concentration were determined.

RESULTS

Five of the 114 patients (4.4%) had coeliac disease. After exclusion of these five patients, the mean IgA AGA concentration was significantly higher (P=0.0005) than that in a reference group. None of the patients had IgA antibodies to endomysium. The mean serum IgA concentration was significantly increased and IgM decreased. Patients with a high concentration of IgA AGA had significantly higher ESR and CRP and a longer duration of morning stiffness than those with a low AGA concentration.

CONCLUSIONS

Patients with PsoA have an increased prevalence of raised serum IgA AGA and of coeliac disease. Patients with raised IgA AGA seem to have more pronounced inflammation than those with a low IgA AGA concentration.

Primary biliary cirrhosis: clinical, pathologic, and helical CT findings in 53 patients

PURPOSE

To evaluate and compare clinical, pathologic, and helical computed tomographic (CT) findings of primary biliary cirrhosis (PBC).

MATERIALS AND METHODS

The authors reviewed the medical records and CT scans of 53 patients who underwent evaluation, treatment, and orthotopic liver transplantation (OLT) at their institution. All patients underwent helical multiphase CT (total, 98 abdominal CT scans; range, one to five scans per patient). Multiple epidemiologic, clinical, and morphologic criteria were evaluated. Advanced disease was defined as hepatic insufficiency leading to OLT within the subsequent 2 years. Clinical and morphologic features were evaluated and compared in the advanced and less advanced cases of PBC.

RESULTS

Common and characteristic findings included the following: 45 (85%) of the 53 patients were women with the onset of disease (diagnosis) in middle age (mean, 50.7 years; range, 26-71 years). The average time from diagnosis to OLT was 6.1 years (range, 1.5-20.0 years). CT findings in advanced PBC often resembled those seen in other forms of cirrhosis, with a small heterogeneously attenuating liver, varices, and splenomegaly. The liver in less advanced disease was usually enlarged or normal in size, with a smooth contour, little atrophy, and lacelike fibrosis and regenerative nodules in nearly one-third of the livers. Patients with less advanced disease frequently had varices (n = 33 [62%]) and ascites (n = 13 [24%]). Lymphadenopathy was seen in 47 (88%) patients. Hepatocellular carcinoma was found in four (8%) patients, two of whom also had chronic hepatitis C. During a follow-up period of 5-72 months (median, 46 months; mean, 42 months) after OLT, only two patients experienced recurrence of PBC.

CONCLUSION

PBC is an important cause of liver failure, with distinctive clinical and CT findings that may assist diagnosis and allow adequate treatment. CT can demonstrate varices and ascites before frank cirrhosis is evident and can help evaluate the progression of the disease.

Liver disease in the elderly

Despite several morphologic and functional changes that have been described in the aging liver, most relevant studies fail to identify a significant age-related deficit in liver function in humans. One of the important age-related changes is a decrease in regenerative capacity, which may partly explain the impaired recovery after severe viral and toxic injury in the elderly. Nevertheless, livers from older subjects are used successfully for transplantation. Substantial morbidity and mortality in the elderly is attributable to liver diseases, and the number of patients older than 65 years of age with chronic liver disease is increasing rapidly. Although there are no liver diseases specific to advanced age, the presentation, clinical course and management of liver diseases in the elderly may differ in important respects from those of younger individuals.

Cholestatic syndromes

New insights into the regulation of hepatobiliary transport proteins have provided the basis for a better understanding of the pathogenesis of cholestatic liver diseases. Mutations of transporter genes can cause hereditary cholestatic syndromes, the study of which has shed much light on the basic mechanisms of bile secretion and cholestasis. Important new studies have been published about the pathogenesis, clinical features, and treatment of primary biliary cirrhosis, primary sclerosing cholangitis, cholestasis of pregnancy, total parenteral nutrition-induced cholestasis, and drug-induced cholestasis.