Primary biliary cirrhosis: epidemiology helping the clinician

The effect of liver transplantation on fatigue in patients with primary biliary cirrhosis: a prospective study

BACKGROUND & AIMS

The role of liver transplantation (LT) for the relief of fatigue in patients with primary biliary cirrhosis (PBC) is unclear, and while many centers exclude fatigue as an indication for transplantation, there have been no studies to prospectively evaluate the impact of LT on fatigue. We aimed at assessing the severity of fatigue in LT candidates with PBC and the impact of LT on fatigue.

METHODS

In a prospective, longitudinal study, we used the PBC-40 questionnaire in 49 adult patients with PBC at listing and at 6, 12, and 24 months after LT and in two sex- and age-matched cohorts of community controls and non-transplanted PBC patients. Correlation analysis was used to assess the relationship between liver function and fatigue. ANOVA was used to compare the variation of fatigue score before and after LT.

RESULTS

There was no correlation between MELD and fatigue before LT (r(2)=0.01). Overall, the fatigue score after LT was substantially lower than before LT, falling from 40.7 ± 11.4 pre-transplant to 27.7 ± 9.5, 28.7 ± 10.1, 26.2 ± 10.1 (p<0.0001) at 6, 12, and 24 months after LT, respectively. The same improvement of fatigue was observed in both low-MELD (<17) and high-MELD (≥ 17) patients. Improvement in fatigue was also evident in the comparison with a "non-transplant PBC" control group (31.1 ± 11.6, p=0.03). However, 44% of the total cohort, and 47% of those with low-MELD, for whom the probability of dying of LT may be higher than that of dying without LT, had moderate to severe fatigue (defined as a fatigue score ≥ 29) at two years after LT. Moreover, fatigue scores at two years were higher in the transplant PBC cohort compared to a cohort of community controls (17.8 ± 5.9, p<0.0001).

CONCLUSIONS

Liver transplantation is associated with improvement in fatigue in patients with PBC. However, a substantial proportion of patients continue to suffer from significant fatigue after two years. Whether the improvement is enough to justify organ allocation in patients with fatigue alone, without liver failure, is still an open issue. Certainly, in the era of organ shortage, with many patients dying waiting for a graft, this may not represent the optimal use of donated deceased organs.

Bisphosphonates for osteoporosis in primary biliary cirrhosis

BACKGROUND

Bisphosphonates are widely used for treatment of postmenopausal osteoporosis. Patients with primary biliary cirrhosis often have osteoporosis - either postmenopausal or secondary to the liver disease. No systematic review or meta-analysis has assessed the effects of bisphosphonates for osteoporosis in patients with primary biliary cirrhosis.

OBJECTIVES

To assess the beneficial and harmful effects of bisphosphonates for osteoporosis in primary biliary cirrhosis.

SEARCH METHODS

The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, LILACS, clinicaltrials.gov, the WHO International Clinical Trials Registry Platform, and full text searches were conducted until November 2011. Manufacturers and authors were contacted for additional studies during the conductance of the review.

SELECTION CRITERIA

All randomised clinical trials of bisphosphonates in primary biliary cirrhosis compared with placebo or no intervention, or another bisphosphonate, or any other drug.

DATA COLLECTION AND ANALYSIS

Two authors extracted data. RevMan Analysis was used for statistical analysis of dichotomous data with risk ratio (RR) or risk difference (RD) and of continuous data with mean difference (MD) or standardised mean difference (SMD), all with 95% confidence intervals (CI). Methodological components were used to assess risk of systematic errors (bias). Trial sequential analysis was also used to control for random errors (play of chance).

MAIN RESULTS

Six trials were included. Three trials with 106 participants, of which two trials with high risk of bias, did not demonstrate significant effects of bisphosphonates (etidronate or alendronate) versus placebo or no intervention regarding mortality (RD 0.00; 95% CI -0.12 to 0.12, I² = 0%), fractures (RR 0.87; 95% CI 0.29 to 2.66, I² = 0%), or adverse events (RR 1.00; 95% CI 0.49 to 2.04). Two trials with 62 participants with high risk of bias compared one bisphosphonate (etidronate or alendronate) versus another (alendronate or ibandronate) and found no significant difference regarding mortality (RD -0.03; 95% CI -0.14 to 0.07, I² = 0%), fractures (RR 0.95; 95% CI 0.18 to 5.06, I² = 0%), or adverse events (RR 1.00; 95% CI 0.49 to 2.04, I² = 0%). Bisphosphonates had no significant effect on liver-related mortality, liver transplantation, or liver-related morbidity compared with placebo or no intervention, or another bisphosphonate. Bisphosphonates had no significant effect on bone mineral density compared with placebo or no intervention, or another bisphosphonate. Bisphosphonates compared with placebo or no intervention seem to decrease the urinary amino telopeptides of collagen I (NTx) concentration (MD -16.93 nmol bone collagen equivalents/mmol creatinine; 95% CI -23.77 to -10.10; 2 trials with 88 patients; I² = 0%) and serum osteocalcin (SMD -0.81; 95% CI -1.22 to -0.39; 3 trials with 100 patients; I² = 34 %) concentration. The former result was supported by trial sequential analysis, but not the latter. Alendronate compared with another bisphosphonate (ibandronate) had no significant effect on serum osteocalcin concentration (MD -3.61 ng/ml, 95% CI -9.41 to 2.18; 2 trials with 47 patients; I² = 82%) in a random-effects meta-analysis, but it significantly decreased serum osteocalcin (MD -4.40 ng/ml, 95% CI -6.75 to -2.05; 2 trials with 47 patients; I² = 82%), the procollagen type I N-terminal propeptide (MD -8.79 ng/ml, 95% CI -15.96 to -1.63; 2 trials with 47 patients; I² = 38%), and NTx concentration (MD -14.07 nmol bone collagen equivalents/mmol creatinine, 95% CI -24.23 to -3.90; 2 trials with 46 patients; I²=0%) in a fixed-effect model. The latter two results were not supported by trial sequential analyses. There was no statistically significant difference in the number of patients having bisphosphonates withdrawn due to adverse events compared with placebo or no intervention (RD -0.04; 95% CI -0.21 to 0.12; 2 trials with 46 patients; I² = 0%), or another bisphosphonate (RR 0.56; 95% CI 0.14 to 2.17; 2 trials with 62 patients; I² = 0%). One trial with 32 participants and with high risk of bias compared etidronate versus sodium fluoride without finding significant difference regarding mortality, fractures, adverse events, or bone mineral density. Etidronate compared with sodium fluoride significantly decreased serum osteocalcin, urinary hydroxyproline, and parathyroid hormone concentration.

AUTHORS' CONCLUSIONS

We did not find evidence to support or refute the use of bisphosphonates for patients with primary biliary cirrhosis. The data seem to indicate a possible positive intervention effect of bisphosphonates on decreasing urinary amino telopeptides of collagen I concentration compared with placebo or no intervention with no risk of random error. There is need for more randomised clinical trials assessing the effects of bisphosphonates for osteoporosis on patient-relevant outcomes in primary biliary cirrhosis.

An integrated care pathway improves quality of life in Primary Biliary Cirrhosis

BACKGROUND

Clinical management of the chronic autoimmune liver disease, Primary Biliary Cirrhosis (PBC) involves addressing the underlying liver disease and a range of symptoms independent of liver disease severity. We have formally explored how these two perspectives of chronic disease management can be combined into a clinic consultation and impact upon quality of life (QOL) in PBC.

AIMS

To develop and implement the first Integrated Care Pathway (ICP) for the management of liver disease progression and symptom management in PBC.

METHODS

Process mapping of current practice by a multidisciplinary group developed a flowchart of care from which the clinical record evolved. Symptom assessment is incorporated into the PBC ICP (QOL; PBC-40, autonomic symptoms; Orthostatic Grading Scale, daytime sleepiness; Epworth Sleepiness Scale). All patients were considered who attended clinic between July 2005 and June 2006. Symptom assessment was repeated after 1 year in those participating in the initial clinic cohort.

RESULTS

The PBC ICP was successfully introduced into our clinical environment with high levels of patient satisfaction. A total of 225 PBC patients attended over 12 months. Initial QOL assessments were in 195 (87%). Five patients died (3%). Repeat assessment 1 year later occurred in 149 subjects (149/190; 78%). All symptom domains improved after ICP implementation with significant improvements in those with moderate and severe symptoms in all PBC-40 symptom domains (P < 0.02). In those with severe fatigue (n = 38) symptom improvement was even more dramatic (P = 0.002).

CONCLUSION

ICP implementation delivers evidence-based care, leads to improvements in QOL coupled with high levels of patient satisfaction.

An open study of modafinil for the treatment of daytime somnolence and fatigue in primary biliary cirrhosis

BACKGROUND

Fatigue is a debilitating symptom which frequently impairs the quality of life of patients with primary biliary cirrhosis (PBC). Although the mechanisms underpinning fatigue in PBC remain unclear, there is an emerging consensus that CNS mechanisms play a key role. It has recently been shown that there is a strong association between abnormalities in sleep regulation, in particular excessive daytime somnolence, and fatigue severity in PBC. The CNS-acting drug modafinil has an established role in the treatment of excessive daytime somnolence in non-liver disease states.

AIM

To explore, in an open label study, the responses of PBC patients suffering from significant daytime somnolence and associated fatigue to modafinil therapy.

METHODS

All patients in the series (n = 21) underwent daytime somnolence assessment using the Epworth Sleepiness Scale and PBC symptom assessment using the PBC-40, a multi-domain, disease specific, psychometrically robust quality of life measure. Modafinil was started at a dose of 100 mg/day and was titrated according to tolerability and response. Patients underwent repeat Epworth Sleepiness Scale and PBC-40 assessment after 2 months of treatment.

RESULTS

Significant improvement was seen in Epworth Sleepiness Scale scores with modafinil therapy [15 +/- 3 vs. 8 +/- 6, P < 0.0005 (intention-to-treat analysis)]. An equally significant improvement in fatigue severity was also seen [PBC-40 fatigue domain score (46 +/- 6 vs. 34 +/- 12, P < 0.0001) (intention-to-treat analysis)].

CONCLUSIONS

Open label modafinil therapy was associated, where tolerated by patients, with improvement in excessive daytime somnolence and associated fatigue in PBC. Further study in placebo-controlled trials is warranted.

Primary biliary cirrhosis in monozygotic and dizygotic twins: genetics, epigenetics, and environment

BACKGROUND & AIMS

There is growing evidence that the interplay of genetic susceptibility and environmental factors leads to primary biliary cirrhosis (PBC). In particular, family members of an infected individual have up to a 100-fold higher risk of developing PBC. Although concordant rates for identical twins in other autoimmune diseases range between 25% and 50%, there are no such data on PBC. Accordingly, we evaluated the concordance of PBC in a genetically defined population of twin sets and evaluated the clinical characteristics between concordant subjects.

METHODS

We identified 16 pairs of twins within a 1400-family cohort followed up by several centers worldwide, evaluated the diagnosis of PBC in all individuals, and determined the zygosity of sets reported as identical by the analysis of 2 highly variable HLA class II regions and 5 short tandem repeats.

RESULTS

Eight of 16 sets of twins were monozygotic. In 5 of 8 monozygotic twin sets, both individuals had PBC (pairwise concordance rate, 0.63). Among the dizygotic twins (n = 8), no set was found to be concordant for PBC. Interestingly, the age at onset of disease was similar in 4 of 5 concordant sets of monozygotic pairs; however, there were differences in natural history and disease severity.

CONCLUSIONS

The concordance rate of PBC in identical twins is among the highest reported in autoimmunity. However, discordant pairs were identified. The data show not only the role of genetics but also emphasize that either epigenetic factors and/or environment play a critical role.

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.

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.

The true impact of fatigue in primary biliary cirrhosis: a population study

BACKGROUND & AIMS

Patient surveys suggest that fatigue is a common problem in primary biliary cirrhosis (PBC). The actual extent of the problems caused by fatigue in PBC has yet to be determined as previous studies addressing this question have tended to use selected patient subgroups and subjective or non-quantitative fatigue assessment tools. Here, we have attempted to more accurately assess the extent of fatigue in PBC, and the specificity of the symptom for this disease, by the application of an objective measure of fatigue impact (the fatigue impact score [FIS]) to a geographically based patient cohort, age- and sex-matched normal controls, and chronic liver disease controls.

METHODS

Postal completion of the FIS and linked symptom assessment tools.

RESULTS

Median FIS was significantly higher in patients (n = 136) than community controls (40 [0-138] vs. 28 [0-156]; P < 0.0001) and chronic liver disease controls (n = 38) (20.5 [0-145]; P < 0.05). Fatigue scores in the 11 patients who had undergone liver transplantation (median 3.5 years previously) were the same as those in non-transplanted patients with advanced disease.

CONCLUSIONS

Fatigue is a significant and specific problem in PBC. It is not, however, universal and affects fewer patients than has previously been thought to be the case based on data from selected patient cohorts. This definition of the "normal range" for fatigue in PBC will assist in future studies of etiology and therapy.

Primary biliary cirrhosis: new thoughts on pathophysiology and treatment

Primary biliary cirrhosis (PBC) is an idiopathic inflammatory hepatic disorder characterized by granulomatous destruction of small bile ducts and formation of antimitochondrial antibodies. Having found that most patients with PBC have antibody reactivity to retroviral proteins, we recently cloned a retroviral sequence directly from biliary epithelium extracted from PBC livers. Further evidence for an infectious etiology of PBC has been derived from an in vitro model using normal biliary epithelial cells in culture with lymph node extracts from patients with chronic liver disease. In this model, biliary epithelial cells cocultivated with PBC lymph nodes developed a specific phenotype of PBC with immunohistochemical evidence of antimitochondrial antibody reactivity. This model has been used to show that patients with PBC harbor a transmissible agent that may be related to the cloned retrovirus. Pilot studies using antiretroviral treatment for patients with PBC have also supported the involvement of a retrovirus in the disease process. Because the antiretroviral therapy was tolerated without undue adverse events, a multicenter controlled trial is being established to determine whether patients with PBC derive significant benefit from this new line of investigation and management.

Osteoporosis in primary biliary cirrhosis revisited

BACKGROUND

Primary biliary cirrhosis (PBC) is increasingly being diagnosed in the earlier non-cholestatic stages of disease. Accepted wisdom has been that PBC is frequently complicated by osteoporosis. Whether this association holds true for the broader spectrum of PBC patients now recognised has not as yet been studied.

AIMS

To examine the extent to which osteoporosis occurs more commonly in PBC patients than in normal individuals of the same age and sex.

DESIGN

Retrospective review of a large cohort of well characterised PBC patients.

PATIENTS

A total of 272 PBC patients with definite or probable PBC followed up for a mean of 10.1 years (total follow up 2726 patient years) who had at least one bone mineral density measurement (BMD).

RESULTS

In this unselected group of PBC patients, mean Z scores (number of SDs from age and sex matched normal mean values) at the neck of femur (NOF) and lumbar spine (LS) at first BMD measurement (7 (6) years after PBC diagnosis) were -0.1 (1.4) and 0.1 (1.4), respectively. At first BMD measurement, 18 PBC patients had Z scores less than -2.0 and 85 had T scores less than -2.5. No factors predictive of osteoporosis were found in affected patients. A total of 957 BMD measurements were performed (0.35 per patient year of follow up); 220 patients had two or more measurements. No patient went on to develop de novo osteoporosis during follow up. In the 51 patients (who were clinically representative of the whole group) who received no PBC or bone related treatment during follow up, %BMD changes per year at the NOF and LS were -1.6 (3.2) and 0.1 (2.2), respectively. No variance in this "natural" rate of BMD measurement was seen in patients receiving PBC modulating agents (including prednisolone and UDCA) or osteoporosis prophylaxis/therapy. Significant improvement at the LS was seen in patients undergoing liver transplantation.

CONCLUSIONS

Osteoporosis is not a specific complication of PBC.

Primary biliary cirrhosis once rare, now common in the United Kingdom?

There is a widespread impression that the number of patients with the autoimmune liver disease primary biliary cirrhosis (PBC) is increasing, although its incidence and prevalence vary widely. Using thorough case-finding methods and rigorous definitions to assess changes in incidence and prevalence with time and to explore the symptomatology and mortality of the disease in a large group of unselected patients, we performed a descriptive epidemiological study of PBC in a well defined population over a fixed period of time using established diagnostic criteria and with clinical follow-up of all cases. In a population of 2.05 million in northern England 770 definite or probable PBC cases were identified. Prevalence rose from 201.9 per 10(6) in the adult population and 541. 4 per 10(6) women over 40 in 1987 to 334.6 per 10(6) adults and 939. 8 per 10(6) women over 40 in 1994. Incidence was 23 per 10(6) in 1987 and 32.2 per 10(6) in 1994. Three hundred patients died in median follow-up of 6.27 years (141 liver deaths); the standardized mortality ratio was 2.85. At presumed diagnosis, 60.9% had no symptoms of liver disease. By June 1994 62% of prevalent patients had liver symptoms. PBC is apparently increasing. It is still unclear whether this is because of a true increase, case finding, or increased disease awareness. The study draws attention to (1) high mortality from liver disease and non-liver-related causes even in patients initially with no liver symptoms and (2) apparently poor diagnostic awareness of the disease.

Biliary tract inflammatory disorders: primary sclerosing cholangitis and primary biliary cirrhosis

Primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC) are chronic progressive cholestatic diseases that frequently lead to biliary cirrhosis. The exact pathogenesis of these diseases remains elusive but is likely immunologically based. Complications range from fatigue and pruritus to end-stage liver disease. The risk of developing hepatocellular carcinoma is low for patients with PBC, whereas cholangiocarcinoma is common in PSC and carries an ominous prognosis. Although ursodeoxycholic acid is effective in slowing the progression of PBC, no effective medical therapy exists for PSC. Liver transplantation is the only option for patients with end-stage liver disease and yields excellent long-term survival in both groups.