Seladelpar: an investigational drug for the treatment of early-stage primary biliary cholangitis (PBC)

INTRODUCTION

Generic fibrates are used off-label as add-in therapy for the management of primary biliary cholangitis (PBC) but with unproven long-term liver-related survival benefits. The recently developed fibrate, seladelpar, has shown promising results in clinical trials, but these outcomes have been previously marred by safety concerns.

AREAS COVERED

We summarize existing treatment options in PBC and evaluate current trial data for seladelpar in relation to liver biochemistry, symptomology, and safety.

EXPERT OPINION

Seladelpar leads to marked improvement in liver biochemistry and may improve symptoms. Safety concerns around liver toxicity appear to have been addressed. With likely increasing evidence compared to existing off-label fibrates, seladelpar has the potential as an attractive future second-line agent in PBC.

Geo-epidemiology and environmental co-variate mapping of primary biliary cholangitis and primary sclerosing cholangitis

Background & Aims

Autoimmune liver disease (AILD) is thought to result from a complex interplay between genetics and the environment. Studies to date have focussed on primary biliary cholangitis (PBC) and demonstrated higher disease prevalence in more urban, polluted, and socially deprived areas. This study utilises a large cohort of patients with PBC and primary sclerosing cholangitis (PSC) to investigate potential environmental contributors to disease and to explore whether the geo-epidemiology of PBC and PSC are disease-specific or pertain to cholestatic AILD in general.

Methods

All adult patients with PBC and PSC in a tightly defined geographical area within the UK were identified. Point- and area-based analyses and structural equation modelling (SEM) were used to investigate for disease clustering and examine for relationships between prevalence, distribution of environmental contaminants, and socio-economic status.

Results

We identified 2,150 patients with PBC and 472 with PSC. Significant spatial clustering was seen for each disease. A high prevalence of PBC was found in urban, post-industrial areas with a strong coal-mining heritage and increased environmental cadmium levels, whereas a high PSC prevalence was found in rural areas and inversely associated with social deprivation.

Conclusions

This study demonstrates spatial clustering of PBC and PSC and adds to our understanding of potential environmental co-variates for both diseases. Disease clustering, within the same geographical area but over different scales, is confirmed for each disease with distinct risk profiles identified and associations with separate putative environmental factors and socio-economic status. This suggests that different triggers and alternative pathways determine phenotypic expression of autoimmunity in the affected population. Co-variate analysis points towards the existence of specific disease triggers.

Lay summary

This study looked for potential environmental triggers in patients with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) living in the north-east of England and north Cumbria. We found that PBC was more common in urban areas with a history of coal mining and high levels of cadmium whereas PSC was more common in rural areas with lower levels of social deprivation.

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Clustering of PBC and PSC patients occurs with notable geographical differences.

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A high prevalence of PBC is seen in urban, post-industrial areas.

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PSC is more common in rural areas and inversely associated with social deprivation.

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PBC risk is associated with proximity to coal mines and environmental cadmium levels.

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Comprehensive epidemiological study can increase understanding of disease aetiology.

The safety and efficacy of nasobiliary drainage in the treatment of refractory cholestatic pruritus: a multicentre European study

BACKGROUND

Pruritus is a common symptom associated with cholestatic liver diseases. To date only small single centre case series have suggested efficacy of nasobiliary drainage in relieving cholestatic pruritus.

AIM

To perform a multicentre study to evaluate the safety and efficacy of nasobiliary drainage in cholestatic pruritus.

METHODS

This was a retrospective study of all patients treated with nasobiliary drainage for refractory cholestatic pruritus between 2006 and 2015 at five European centres. Pruritus was quantified using a visual analogue scale (VAS) and liver enzymes, serum bilirubin and total serum bile salts (TBS) were measured before (pre-NBD) and after nasobiliary drainage (post-NBD). We analysed the duration of treatment response and associated complications.

RESULTS

In total, 27 patients (59% females) underwent 29 nasobiliary drainage procedures. The median duration of NBD was 7 days. NBD decreased pruritus in 89.6% of cases (VAS from 10.0 to 0.3, P < 0.0001). The median percentage decline in pruritus VAS was 94% and 33% of patients were free of pruritus within 24 h of starting drainage. The duration of treatment response was independent of duration of drainage (P = 0.12) and bile output. Significant improvements were seen in the median levels of serum alkaline phosphatase (P = 0.001) and serum bilirubin (P = 0.03) but not in serum TBS (P = 0.07). Mild post-endoscopic retrograde cholangiopancreatography pancreatitis (31%) was the most frequent complication.

CONCLUSIONS

Nasobiliary drainage is effective in relieving cholestatic pruritus in most patients and has favourable effect on biomarkers of cholestasis. Nasobiliary drainage may be associated with high risk of adverse events, especially pancreatitis. Prospective studies are needed to confirm our findings.

Biliary epithelial senescence and plasticity in acute cellular rejection

Biliary epithelial cells (BEC) are important targets in some liver diseases, including acute allograft rejection. Although some injured BEC die, many can survive in function compromised states of senescence or phenotypic de-differentiation. This study was performed to examine changes in the phenotype of BEC during acute liver allograft rejection and the mechanism driving these changes. Liver allograft sections showed a positive correlation (p < 0.0013) between increasing T cell mediated acute rejection and the number of BEC expressing the senescence marker p21(WAF1/Cip) or the mesenchymal marker S100A4. This was modeled in vitro by examination of primary or immortalized BEC after acute oxidative stress. During the first 48 h, the expression of p21(WAF1/Cip) was increased transiently before returning to baseline. After this time BEC showed increased expression of mesenchymal proteins with a decrease in epithelial markers. Analysis of TGF-β expression at mRNA and protein levels also showed a rapid increase in TGF-β2 (p < 0.006) following oxidative stress. The epithelial de-differentiation observed in vitro was abrogated by pharmacological blockade of the ALK-5 component of the TGF-β receptor. These data suggest that stress induced production of TGF-β2 by BEC can modify liver allograft function by enhancing the de-differentiation of local epithelial cells.

Fatigue severity remains stable over time and independently associated with orthostatic symptoms in chronic fatigue syndrome: a longitudinal study

OBJECTIVES

to examine fatigue variability over time in chronic fatigue syndrome (CFS) and the effect of other symptoms on its predictability.

DESIGN

longitudinal cohort study of patients with CFS (Fukuda criteria).

SETTING

specialist CFS clinical service.

SUBJECTS

phase 1: 100 patients who participated in a study of CFS symptoms in 2005 were revisited in 2009. Phase 2: 25 patients completed fatigue diaries to address intra- and inter-day variability in perceived fatigue.

MAIN OUTCOME MEASURES

phase 1: subjects completed fatigue impact scale (FIS), Epworth sleepiness scale (ESS), orthostatic grading scale (OGS) and hospital anxiety and depression scale (HADS). Changes in variables represented the differences between 2005 and 2009. Phase 2: subjects rated fatigue on a scale of 0 (no fatigue) to 10 (severe fatigue) four times a day for 5 weeks.

RESULTS

symptom assessment tools were available in both 2005 and 2009 for 74% of patients. FIS and HADS depression (HAD-D) and anxiety (HAD-A) scores significantly improved during follow-up whereas ESS and OGS remained stable. FIS improved in 29/74 (39%) subjects, and by ≥ 10 points in 19 (26%). FIS worsened by ≥ 10 points in 33/74 (45%) subjects. On multivariate analysis, independent predictors of current fatigue (FIS in 2009) were FIS in 2005, HAD-D in 2009, OGS in 2009 and change in HAD-A. Reported fatigue was stable from week to week and from day to day. Patients reported higher fatigue in the morning (mean ± SD; 6.4 ± 2), becoming significantly lower at lunchtime (6.2 ± 2; P < 0.05) and increasing again to 7 ± 2 at bedtime.

CONCLUSIONS

current fatigue is independently associated with current autonomic symptom burden, current depression and change in anxiety during follow-up. These findings have implications for targeted symptom management in CFS.

Abnormalities in pH handling by peripheral muscle and potential regulation by the autonomic nervous system in chronic fatigue syndrome

OBJECTIVES

To examine muscle acid handling following exercise in chronic fatigue syndrome (CFS/ME) and the relationship with autonomic dysfunction.

DESIGN

Observational study.

SETTING

Regional fatigue service. SUBJECTS & INTERVENTIONS: Chronic fatigue syndrome (n = 16) and age and sex matched normal controls (n = 8) underwent phosphorus magnetic resonance spectroscopy (MRS) to evaluate pH handling during exercise. Subjects performed plantar flexion at fixed 35% load maximum voluntary contraction. Heart rate variability was performed during 10 min supine rest using digital photophlethysmography as a measure of autonomic function.

RESULTS

Compared to normal controls, the CFS/ME group had significant suppression of proton efflux both immediately postexercise (CFS: 1.1 +/- 0.5 mmol L(-1) min(-1) vs. normal: 3.6 +/- 1.5 mmol L(-1) min(-1), P < 0.001) and maximally (CFS: 2.7 +/- 3.4 mmol L(-1) min(-1) vs. control: 3.8 +/- 1.6 mmol L(-1) min(-1), P < 0.05). Furthermore, the time taken to reach maximum proton efflux was significantly prolonged in patients (CFS: 25.6 +/- 36.1 s vs. normal: 3.8 +/- 5.2 s, P < 0.05). In controls the rate of maximum proton efflux showed a strong inverse correlation with nadir muscle pH following exercise (r(2) = 0.6; P < 0.01). In CFS patients, in contrast, this significant normal relationship was lost (r(2) = 0.003; P = ns). In normal individuals, the maximum proton efflux following exercise were closely correlated with total heart rate variability (r(2) = 0.7; P = 0.007) this relationship was lost in CFS/ME patients (r(2) < 0.001; P = ns).

CONCLUSION

Patients with CFS/ME have abnormalities in recovery of intramuscular pH following standardised exercise degree of which is related to autonomic dysfunction. This study identifies a novel biological abnormality in patients with CFS/ME which is potentially open to modification.

Primary biliary cirrhosis is associated with falls and significant fall related injury

BACKGROUND

Osteoporosis and autonomic dysfunction are prevalent in the autoimmune liver disease primary biliary cirrhosis (PBC). Postural hypotension is one consequence of autonomic dysfunction and is a recognized risk factor for falls, which, alongside osteoporosis could lead to significant injury and fractures.

AIM

To determine the prevalence and sequelae of falls in PBC and to identify modifiable risk factors.

DESIGN

Cross-sectional, geographical, population census of PBC and two control groups: primary sclerosing cholangitis and a community dwelling population. Multidisciplinary falls assessment of a representative group of PBC.

METHODS

Symptom assessment tools, completed by the three cohorts, determined the prevalence of falls, injuries and associated symptoms. Multidisciplinary assessments, adhering to NICE guidelines, identified modifiable fall associations.

RESULTS

Significantly more of the PBC population had fallen (72% P < 0.001) than both control groups. Fifty-five percent had fallen in the last year (P < 0.001), and 22% more than once in the last year (P < 0.01). Seventy percent of PBC fallers were injured, 27% fractured a bone and 19% were admitted to hospital, all significantly more common than controls. Postural dizziness was significantly worse in fallers (P < 0.001), as were balance (P < 0.001) and lower limb strength (P = 0.002). Lower limb strength was independently associated with number of falls in previous year (beta = 0.184, P < 0.001).

CONCLUSION

Falls and resultant injury are prevalent in PBC and more common than previously recognized. Addressing postural dizziness, poor balance and lower limb weakness using a multidisciplinary approach has the potential to reduce falls, morbidity and mortality and as a result improve quality of life.

Perceived fatigue is comparable between different disease groups

BACKGROUND

Studies have established that levels of fatigue vary between different patient groups. It is less clear whether the nature, as opposed to severity of fatigue differs between groups.

OBJECTIVE

To examine descriptions of fatigue by patients with a range of chronic diseases and determine the relationship between symptom domains.

DESIGN

Retrospective review of Fatigue Impact Scale (FIS) data.

SETTING

Fatigue Research Group.

PARTICIPANTS

Six hundred subjects in five chronic disease groups and one (n = 45) normal control group.

MAIN OUTCOME MEASURES

Statistical analysis was performed to assess the effect of increasing fatigue and the overlap of FIS domain scores between disease groups by calculation of geometric means as proportions summed to 1 in each FIS domains, whilst controlling for total score.

RESULTS

Those with lower scores exhibit relatively higher physical scores than patients with higher total scores. In contrast, as total score increases, so does the proportion accounted for by the cognitive and psychosocial scores. This was not related to a threshold effect as the maximum total score of 40 in the physical domain was only achieved in three patients (<1%). Average domain proportions between patient groups did not vary to any degree among physical (0.30-0.39), cognitive (0.15-0.23) and psychosocial (0.42-0.47) domain proportions of the patient groups.

CONCLUSION

Perceived fatigue is similar between patient groups. Increasing scores were not related to simply reaching the maximum threshold in the physical domain. Studies have confirmed a positive-structured approach to symptom management in one fatigue-associated chronic disease, primary biliary cirrhosis, leads to significant improvements in quality of life. We suggest that, with a similar approach, the same might be true in other chronic diseases where moderate fatigue is a significant problem.

Fatigue in non-alcoholic fatty liver disease (NAFLD) is significant and associates with inactivity and excessive daytime sleepiness but not with liver disease severity or insulin resistance

OBJECTIVE

To quantify fatigue in non-alcoholic fatty liver disease (NAFLD), to determine whether perceived fatigue reflects impairment of physical function and to explore potential causes.

PATIENTS AND METHODS

A cohort study was carried out on 156 consecutive patients with histologically proven NAFLD studied in two cohorts. Phase 1 determined the perceived fatigue experienced by NAFLD patients (assessed using the Fatigue Impact Scale (FIS)) in comparison with normal and liver disease controls, and the relationship to physical function (actigraphy). In phase 2, biological associations of fatigue in NAFLD were explored.

RESULTS

Fatigue was markedly higher in NAFLD patients than in controls (mean (SD) FIS 51 (38) vs 8 (12), p<0.001). NAFLD patients showed significantly lower physical activity over 6 days (7089 (2909) mean steps/day vs 8676 (2894), p = 0.02). A significant inverse correlation was seen between FIS and physical activity (r = 0.1, p = 0.02). Fatigue experienced by NAFLD patients was similar to that in primary biliary cirrhosis (n = 36) (FIS 64 (9) vs 61 (2), p = NS). No association was seen between FIS and biochemical and histological markers of liver disease severity or insulin resistance (homeostasis model assessment (HOMA)) (r < 0.005). Significant association was seen between fatigue severity and daytime somnolence (Epworth Sleepiness Scale) (r = 0.2, p < 0.001).

CONCLUSION

Fatigue is a significant problem in NAFLD, is similar in degree to that in primary biliary cirrhosis patients and is associated with impairment in physical function. Fatigue in NAFLD appears to be unrelated to either severity of underlying liver disease or insulin resistance, but is associated with significant daytime somnolence.

Symptoms of autonomic dysfunction in chronic fatigue syndrome

BACKGROUND

Chronic fatigue syndrome (CFS) is common and its cause is unknown.

AIM

To study the prevalence of autonomic dysfunction in CFS, and to develop diagnostic criteria.

DESIGN

Cross-sectional study with independent derivation and validation phases.

METHODS

Symptoms of autonomic dysfunction were assessed using the Composite Autonomic Symptom Scale (COMPASS). Fatigue was assessed using the Fatigue Impact Scale (FIS). Subjects were studied in two groups: phase 1 (derivation phase), 40 CFS patients and 40 age- and sex-matched controls; phase 2 (validation phase), 30 CFS patients, 37 normal controls and 60 patients with primary biliary cirrhosis.

RESULTS

Symptoms of autonomic dysfunction were strongly and reproducibly associated with the presence of CFS or primary biliary cirrhosis (PBC), and correlated with severity of fatigue. Total COMPASS score >32.5 was identified in phase 1 as a diagnostic criterion for autonomic dysfunction in CFS patients, and was shown in phase 2 to have a positive predictive value of 0.96 (95%CI 0.86-0.99) and a negative predictive value of 0.84 (0.70-0.93) for the diagnosis of CFS.

DISCUSSION

Autonomic dysfunction is strongly associated with fatigue in some, but not all, CFS and PBC patients. We postulate the existence of a 'cross-cutting' aetiological process of dysautonomia-associated fatigue (DAF). COMPASS >32.5 is a valid diagnostic criterion for autonomic dysfunction in CFS and PBC, and can be used to identify patients for targeted intervention studies.

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.

Calcaneal bone mineral density in older patients who have fallen

BACKGROUND

Annually, 35-40% of those aged >65 years fall; up to 5% of such falls result in fracture. Fracture is determined both by propensity to fall and by bone fragility.

AIM

To determine osteoporosis prevalence and predictors in patients who have fallen.

DESIGN

Observational cross-sectional study.

METHODS

We measured calcaneal BMD in 408 consecutive patients aged >50 years attending after falling. Fall number, fracture history, weight, height, and risk factors for falls and osteoporosis were recorded. T scores (SD above or below the mean for young adults) were derived in both sexes, and Z scores (SD above or below age-related normal score) in females.

RESULTS

In females (n = 300, 74%), mean (SD) T score was -1.1(1.6), and mean Z score was 0(1.4); 127 (42%) had osteoporosis (T score < - 1.6). ROC curves confirmed significant relationships between osteoporosis and age, weight and height (all p < 0.0001). Incorporating fracture history, our model (fracture aged >50 years, age >83 years, weight <57 kg, height <153 cm as dichotomous variables) predicted osteoporosis with 91% sensitivity, 34% specificity. Of 108 male fallers, 36 (33%) had osteoporosis. Age, height and weight all predicted osteoporosis (p < 0.02). The resulting model (fracture aged >50 years, age > or =80 years, weight < or =68 kg, height < or =167 cm as dichotomous variables) predicted osteoporosis with 92% sensitivity, 30% specificity.

DISCUSSION

Osteoporosis prevalence is not increased in female fallers compared to age-related norms; empirical use of osteoporosis treatment solely on the basis of falls thus appears inappropriate. In both sexes, the factors predicting osteoporosis were age, height and weight. Where BMD is not practical, possible or economical, our model may be a sensitive means of predicting fallers with osteoporosis.

Four year follow up of fatigue in a geographically defined primary biliary cirrhosis patient cohort

BACKGROUND AND AIMS

Fatigue is the commonest symptom described by patients in most populations with the autoimmune liver disease primary biliary cirrhosis (PBC), and appears to be unrelated to liver disease severity. At present, it is unclear how the fatigue experienced by patients (only characterised to date in cross sectional studies) evolves over time. In this study, we set out to address how fatigue had changed over four years of follow up in a geographically defined cohort of PBC patients who participated in an earlier cross sectional study of fatigue impact.

METHODS

Participants in the original 2000 study who were still alive in 2004 were asked to complete the same fatigue assessment tool (fatigue impact score, FIS). In those who had died between 2000 and 2004, medical notes, death certificates, and primary care records were reviewed.

RESULTS

A total of 108 of the original cohort of 136 patients were alive at the time of the follow up study, 99 of whom (92%) participated in the follow up study. With the exception of four patients who underwent transplantation between 2000 and 2004, all of whom showed significant improvement in fatigue severity as assessed by FIS, fatigue severity was unchanged over four years of follow up. Among the 28 patients who died during the follow up period, survival was significantly lower in patients who were fatigued at the 2000 baseline (FIS above the median for the whole PBC population (40/160); log rank test, p = 0.006 v non-fatigued patients at baseline). Increased fatigue severity was independently associated with decreased survival on multivariate analysis. Fatigued PBC subjects were significantly more likely to have suffered a cardiac death than non-fatigued patients.

CONCLUSIONS

The fatigue phenotype appears to be highly stable in PBC. The presence of fatigue in PBC is independently associated with a significantly increased risk of death in general, and cardiac death in particular. Factors underpinning fatigue in PBC, and the mechanisms whereby fatigue is associated with increased mortality, warrant further study.

Development, validation, and evaluation of the PBC-40, a disease specific health related quality of life measure for primary biliary cirrhosis

BACKGROUND AND AIMS

Study of health related quality of life (HRQOL) and the factors responsible for its impairment in primary biliary cirrhosis (PBC) has, to date, been limited. There is increasing need for a HRQOL questionnaire which is specific to PBC. The aim of this study was to develop, validate, and evaluate a patient based PBC specific HRQOL measure.

SUBJECTS AND METHODS

A pool of potential questions was derived from thematic analysis of indepth interviews carried out with 30 PBC patients selected to represent demographically the PBC patient population as a whole. This pool was systematically reduced, pretested, and cross validated with other HRQOL measures in national surveys involving a total of 900 PBC patients, to produce a quality of life profile measure, the PBC-40, consisting of 40 questions distributed across six domains. The PBC-40 was then evaluated in a blinded comparison with other HRQOL measures in a further cohort of 40 PBC patients.

RESULTS

The six domains of PBC-40 relate to fatigue, emotional, social, and cognitive function, general symptoms, and itch. The highest mean domain score was seen for fatigue and the lowest for itch. The measure has been fully validated for use in PBC and shown to be scientifically sound. PBC patient satisfaction, measured in terms of the extent to which a questionnaire addresses the problems that they experience, was significantly higher for the PBC-40 than for other HRQOL measures.

CONCLUSION

The PBC-40 is a short easy to complete measure which is acceptable to PBC patients and has significantly greater relevance to their problems than other frequently used HRQOL measures. Its scientific soundness, shown in extensive testing, makes it a valuable instrument for future use in clinical and research settings.

Hypothesis: epithelial-to-mesenchymal transition is a common cause of chronic allograft failure

Renal, hepatic, and lung allografts are compromised by aggressively deteriorating function. This chronic process is produced by an overall burden of organ damage, but the pathophysiology remains poorly understood. Rates of chronic rejection in the lung, for example, have not substantially improved over the last decade, despite new immunosuppressive drugs and improvements in surgical procedure. We present a hypothesis that epithelial-to-mesenchymal transition is a common cause of chronic allograft failure. Research in this area may provide insights into chronic rejection of kidney, liver, and lung allografts that impact on future therapeutic strategies.

Chemokine receptor 5 and primary biliary cirrhosis: a two-centre genetic association study

BACKGROUND

Chemokines and their receptors are important mediators of leucocyte trafficking and are suggested to be critical for establishment of inflammatory autoimmune processes. CC chemokine receptor 5 (CCR5) is expressed preferentially by CD4+ T cells. We hypothesised that the CCR5delta(Delta)32 genotype, which impairs surface expression of CCR5 in heterozygotes and is linked to a functional polymorphism of CD45RA expressed on suppressor-inducer-like 'naive' CD4+ T cells, may modulate the inflammatory process in primary biliary cirrhosis (PBC).

METHODS

CCR5Delta32 polymorphism was determined by PCR in 226 Caucasian PBC patients and 197 racially matched controls from two geographical areas, Newcastle, UK and Padua, Italy. (UK: 144 PBC, 105 controls, Italy: 82 PBC, 92 controls).

RESULTS

When the two series were analysed separately, there were no significant differences in the genotype distribution comparing patients and controls (UK: wt/wt 72% vs 76%; wt/Delta32 28% vs 22%; Delta32/Delta32 0% vs 2%, P=0.24; Italy: wt/wt 72% vs 82%; wt/Delta32 27% vs 17%; Delta32/Delta32 0% vs 1%, P=0.14). However, when the data for the two series were pooled and reanalysed, we found an increase in the CCR5Delta32 mutation in PBC patients vs controls (28% vs 21%, OR=1.43, P=0.03), but there was no evidence that this Delta32 polymorphism is associated with less severe disease.

CONCLUSIONS

Although this two-centre genetic association study is large compared with others performed in PBC, taken separately, each geographically based cohort of patients and controls is underpowered to detect a small effect of this functional polymorphism. This emphasises the need for far larger case-control collections to address which polymorphic markers or haplotypes might modify the pathogenesis and clinical course of PBC. We propose that multi-centre collaboration on an international scale in 'orphan' complex liver diseases such as (PBC) is supported by the International Association for the Study of the Liver and promoted via their journal with development of a brief format for web-based publication of studies.

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.

Apoptosis as a mechanism for cell surface expression of the autoantigen pyruvate dehydrogenase complex

A number of antigens implicated in the pathogenesis of autoimmune diseases including Sjogren's syndrome and systemic lupus erythematosus (SLE) are expressed aberrantly by apoptotic cells. It is also known that apoptogenic proteins are released from the mitochondrial intermembrane space at an early stage during the induction and development of apoptosis. Combination of this evidence led us to test the hypothesis that apoptotic mechanisms provide an explanation for the abnormal expression of the inner mitochondrial enzyme, pyruvate dehydrogenase complex (PDC), observed on the surface of some cells in patients with the autoimmune liver disease primary biliary cirrhosis (PBC). Using one murine and two human cell lines it was found that the induction of apoptosis led to early detection of PDC within the cytoplasm. However, cytochrome c oxidase subunit 4 (COX 4), which is also present on the inner surface of the inner mitochondrial membrane, remained within the mitochondria. Immunoreactive PDC was also detected on the outer surface of the intact plasma membrane of cells sampled after the induction of apoptosis. Serial release of PDC to the cytoplasm and then onto the external surface of the plasma membrane provides direct evidence that the antigen on the cell surface is of mitochondrial origin. Immunoreactivity specific for PDC is strongly implicated in the pathogenesis of PBC, but this autoantigen is normally concealed from the immune system by three membrane systems. Release of PDC onto the cell surface during apoptosis provides a possible route for recognition of this antigen by the immune system which could contribute to both afferent and efferent phases of the disease process.

Fatigue and primary biliary cirrhosis: association of globus pallidus magnetisation transfer ratio measurements with fatigue severity and blood manganese levels

BACKGROUND AND AIM

Fatigue is the commonest symptom in primary biliary cirrhosis (PBC), affecting individuals at all stages of disease. The pathogenesis of fatigue in PBC is unknown although rat models suggest a central nervous system (CNS) cause. We examined the hypothesis that a CNS abnormality related to cholestasis, rather than cirrhosis per se, underlies this symptom.

PATIENTS AND METHODS

Fourteen patients with precirrhotic PBC (stage I-II disease), four patients with stage III-IV PBC, and 11 healthy women were studied using cerebral magnetisation contrast imaging and proton magnetic resonance spectroscopy (MRS).

RESULTS

The globus pallidus magnetisation transfer ratio (MTR), a quantifiable tissue characteristic that may be abnormal in the presence of normal magnetic resonance imaging, was significantly reduced in precirrhotic PBC patients compared with healthy controls. These measurements correlated with blood manganese levels and were more abnormal in the more fatigued subjects. There were no differences in MRS measurements between the three study groups, suggesting that the abnormal MTR was not related to hepatic encephalopathy.

CONCLUSION

This study suggests that impairments in liver function in PBC may adversely affect the brain long before the development of cirrhosis and hepatic encephalopathy, possibly as a result of altered manganese homeostasis within the CNS.

Oral antioxidant supplementation for fatigue associated with primary biliary cirrhosis: results of a multicentre, randomized, placebo-controlled, cross-over trial

BACKGROUND

We have previously reported, in an uncontrolled trial, an improvement in fatigue scores in patients with primary biliary cirrhosis given oral antioxidant supplementation. We now present data from a controlled trial.

PATIENTS AND METHODS

Sixty-one patients with primary biliary cirrhosis-associated fatigue were randomized into a double-blind, placebo-controlled, cross-over trial. Participants received 12 weeks each of placebo and antioxidant supplementation (vitamins A, C and E, selenium, methionine and ubiquinone) in random order, separated by a 4-week washout period. The primary trial outcome (fatigue) was assessed using the Fisk scale. Other symptoms of primary biliary cirrhosis were measured using Likert and visual analogue scales.

RESULTS

Forty-four patients completed both arms of the trial. No significant changes in fatigue were recorded in the active phase of treatment (median improvement in Fisk score, 1; P = 0.61). Small improvements in Fisk scores were recorded during placebo therapy (median improvement, 4; P = 0.03). Neither medication was associated with improvement in any other symptoms related to primary biliary cirrhosis. Adverse effects were more common during active therapy and were mild and self-limiting. One patient died from unrelated causes during active treatment.

CONCLUSIONS

Although oral antioxidant supplementation appears to be safe, we could not find any evidence for a beneficial effect on fatigue or other liver-related symptoms.

The immunology of primary biliary cirrhosis: the end of the beginning?

The chronic liver disease primary biliary cirrhosis (PBC) is characterised by autoreactive B-cell and T-cell responses directed against mitochondrial antigens. In recent years these responses have been extensively characterised and the principal PBC associated autoantigen identified as pyruvate dehydrogenase complex (PDC). The identification of anti-PDC responses (present in over 95% of PDC patients) has given rise to important questions pertinent to our understanding of the pathogenesis of PBC. What specific role to anti-PDC responses play in target cell damage? How and why does immune tolerance break down to as highly conserved and ubiquitously expressed self-antigen as PDC? Why does breakdown in tolerance to an antigen present in all nucleated cells result in damage restricted to the intra-hepatic bile ducts? In attempting to answer these key questions we have, in this review, proposed a unifying hypothesis for the pathogenesis of PBC.

Hepatitis and liver dysfunction with rifampicin therapy for pruritus in primary biliary cirrhosis

There is evidence to suggest that rifampicin is an effective second line therapy for controlling pruritus in patients with chronic cholestatic liver disease. It is most widely used as an antipruritic agent in the autoimmune cholestatic liver disease, primary biliary cirrhosis (PBC). Rifampicin has been reported as causing hepatitis in patients being treated for tuberculosis. Most reports of this have been confounded however by the concurrent use of other hepatotoxic antitubercular therapy. Here we report a single centre experience of the use of rifampicin in PBC, and describe three cases of significant hepatitis associated with rifampicin therapy. Two of these patients had significant impairment of liver synthetic function (necessitating liver transplantation in one case). These are the first reports of impaired hepatic synthetic function due to rifampicin monotherapy. Rifampicin caused significant hepatitis in 7.3% (95% confidence interval 2.5-19.4%) of patients treated for cholestatic liver disease in our centre.

Familial primary biliary cirrhosis and autoimmune cholangitis

AIM

Autoimmune cholangitis has been proposed as a separate disease entity from primary biliary cirrhosis without serum antimitochondrial antibodies. The ultimate answer to the question of whether autoimmune cholangitis and primary biliary cirrhosis are distinct will require detailed comparison of aetiologic factors and pathogenic mechanisms.

METHODS AND RESULTS

Two families are described each of which has one member with classical antimitochondrial antibody positive biopsy-proven primary biliary cirrhosis and a first degree relative with antimitochondrial antibody negative but antinuclear antibody positive autoimmune cholangitis (biopsy proven in one case). Study of such families should allow analysis of the contribution of shared genetic risk factors versus varying environmental triggering mechanisms to disease pathogenesis.

CONCLUSIONS

We suggest a European registry of families, such as the two described, which are rare within one centre, to facilitate elucidation of pathogenetic factors.