Loss of capacity to recover from acidosis in repeat exercise is strongly associated with fatigue in primary biliary cirrhosis

AHCC inhibited hepatic stellate cells activation by regulation of cytoglobin induction via TLR2-SAPK/JNK pathway and collagen production via TLR4-NF-κβ pathway

Cirrhosis, which represents the end stage of liver fibrosis, remains a life-threatening condition without effective treatment. Therefore, prevention of the progression of liver fibrosis through lifestyle habits such as diet and exercise is crucial. The functional food AHCC, a standardized extract of cultured Lentinula edodes mycelia produced by Amino Up Co., Ltd. (Sapporo, Japan)] has been reported to be effective in improving the pathophysiology of various liver diseases. In this study, the aim was to analyze the influence of AHCC on hepatic stellate cells, which are responsible for liver fibrosis. Eight-week-old male C57BL6/j mice were induced with liver fibrosis by intraperitoneal injection of carbon tetrachloride. Simultaneously, they were orally administered 3% AHCC to investigate its impact on the progression of liver fibrosis. Using the human hepatic stellate cell (HHSteC) line, we analyzed the influence of AHCC on the expression of molecules related to hepatic stellate cell activation. The administration of AHCC resulted in reduced expression of collagen1a, α smooth muscle actin (αSMA), and heat shock protein 47 in the liver. Furthermore, the expression of cytoglobin, a marker for quiescent hepatic stellate cells, was enhanced. In vitro study, it was confirmed that AHCC inhibited αSMA by inducing cytoglobin via upregulating the stress-activated protein kinase/Jun NH2-terminal kinase (SAPK/JNK) pathway through Toll-like receptor (TLR) 2. In addition, AHCC suppressed collagen1a production by hepatic stellate cells through TLR4-NF-κβ pathway. AHCC was suggested to suppress hepatic fibrosis by inhibition of hepatic stellate cells activation. Daily intake of AHCC from mild fibrotic stages may have the potential to prevent the progression of liver fibrosis.NEW & NOTEWORTHY AHCC, a standardized extract of cultured Lentinula edodes mycelia, suppresses liver fibrosis progression by induction of cytoglobin via the Toll-like receptor 2 (TLR2)-stress-activated protein kinase/Jun NH2-terminal kinase (SAPK/JNK) pathway and the inhibition of collagen production via the TLR4-NFκβ pathway in hepatic stellate cells. Daily oral administration of AHCC from the stage of MASLD may have the potential to prevent disease progression to MASH with fibrosis.

A home-based exercise programme attenuates fatigue in primary biliary cholangitis: Results from the EXCITED clinical trial

Background & Aims

Fatigue is a commonly reported symptom of primary biliary cholangitis (PBC). We conducted a single-arm, open-label clinical trial to assess the efficacy of a physiotherapist-led home-based exercise programme (HBEP) in patients with PBC and moderate-to-severe fatigue (NCT04265235).

Methods

A 12-week individualised HBEP (aerobic + resistance based) was delivered to patients with a PBC-40 fatigue domain score ≥33. The primary efficacy outcome measure was a reduction in fatigue severity by ≥5 points. Secondary outcome measures included other domains of PBC-40, the FIS (fatigue impact scale), ESS (Epworth sleepiness score), HADS (hospital anxiety and depression scale), aerobic capacity (ISWT [incremental shuttle walk test], Duke activity status index (predicted VO₂ peak) and physical function (short physical performance battery [SPPB]).

Results

A total of 31 patients were recruited, of whom 30 completed the 12-week HBEP (29 women; median age 53 years, median alkaline phosphatase value: 1.5x the upper limit of normal, median bilirubin: 12 μmol/L, and median baseline PBC-40 fatigue score 42). The primary outcome was met by 26 patients, with a median reduction in PBC-40 fatigue score of -10.5 points (IQR -9 to -13; p <0.001). Reductions were also observed in the symptom, cognition, and emotion domains of PBC-40, and in the FIS, ESS and HADS (p <0.01 for all measures). This was alongside increases in the median ISWT (+90 m; IQR 57.5-110), predicted VO₂ peak (+2.41 ml/kg/min; IQR 0.01-4.05), and SPPB (+1 point; IQR 0-1.4) (all p <0.001). 28 participants achieved the maximum SPPB score of 12/12 (vs. 13 patients at baseline; p <0.001). No significant adverse events were reported.

Conclusion

This proof-of-concept study shows that a HBEP is safe, feasible, and has the potential to attenuate fatigue. Controlled trials are needed to validate the efficacy of exercise interventions in PBC.

Impact and implications

Fatigue is a common symptom in primary biliary cholangitis (PBC), and is linked to cognitive dysfunction, somnolence, and reduced activity. The pathogenesis is multifactorial, and muscle bioenergetic abnormalities have been proposed to contribute. In this study, we show that a home-based exercise programme, consisting of aerobic and resistance-based sets, can be safely delivered to people living with PBC. In addition, the programme led to a reduction in fatigue severity, less daytime sleepiness and improved cognitive function.

Sleep disturbances in chronic liver disease

Sleep disturbances are common in chronic liver disease and significantly impact patient outcomes and quality of life. The severity and nature of sleep disturbances vary by liver disease etiology and severity. While there is ongoing research into the association between liver disease and sleep-wake dysfunction, the underlying pathophysiology varies and, in many cases, is poorly understood. Liver disease is associated with alterations in thermoregulation, inflammation, and physical activity, and is associated with disease-specific complications, such as HE, that may directly affect sleep. In this article, we review the relevant pathophysiologic processes, disease-specific sleep-wake disturbances, and clinical management of CLD-associated sleep-wake disturbances.

The influence of muscle performance and fatigue on prognosis in patients with compensated liver disease

BACKGROUND

Poor muscle function is associated with a negative prognosis in advanced liver disease but the impact in compensated chronic liver disease is unknown. Similar prognostic uncertainty applies to fatigue. We aimed to assess the prognostic value of muscle performance and fatigue in a cohort of patients with compensated chronic liver disease.

METHODS

We followed 241 patients with compensated chronic liver disease included in a study between 2010 and 2014. Subjects were 52 ± 15 years (mean ± SD; 134 females). All subjects performed four muscle function tests: "Timed Up and Go" test, walking speed, handgrip strength, and standing heel-rises. Fatigue was evaluated by fatigue impact scale. Follow up data was acquired through hospital records and registries.

RESULTS

During follow up of 6.75 ± 1.4 years, 13 patients died (5.5%) and 11 (4.5%) patients underwent liver transplantation. A timed up and go over 10 s was not significantly associated with a lower survival (Kaplan-Meier, log rank test p = 0.132), or with transplant free survival (p = 0.543), Fig. 3. It was also not specifically associated with liver related causes of death (p = 0.597). The other physical functioning tests and fatigue were not significantly associated with mortality or transplant-free survival (p > 0.05 for all) except for maximal walking speed (2.2 vs. 1.9 m/s, p = 0.007).

CONCLUSIONS

Our study suggests that muscle function and fatigue are not key prognostic factors in compensated chronic liver disease. However, further confirmation in future studies is needed.

New Treatment Paradigms in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is an archetypal autoimmune disease. Chronic lymphocytic cholangitis is associated with interface hepatitis, ductopenia, cholestasis, and progressive biliary fibrosis. People living with PBC are frequently symptomatic, experiencing a quality-of-life burden dominated by fatigue, itch, abdominal pain, and sicca complex. Although the female predominance, specific serum autoantibodies, immune-mediated cellular injury, as well as genetic (HLA and non-HLA) risk factors, identify PBC as autoimmune, to date treatment has focused on cholestatic consequences. Biliary epithelial homeostasis is abnormal and contributes to disease. The impact of cholangiocyte senescence, apoptosis, and impaired bicarbonate secretion enhances chronic inflammation and bile acid retention. First-line therapy is a non-specific anti-cholestatic agent, ursodeoxycholic acid. For those with residual cholestasis biochemically, obeticholic acid is introduced, and this semisynthetic farnesoid X receptor agonist adds choleretic, anti-fibrotic, and anti-inflammatory activity. Future PBC licensed therapy will likely include peroxisome proliferator activated receptor (PPAR) pathway agonists, including specific PPAR-delta agonism (seladelpar), as well as elafibrinor and saroglitazar (both with broader PPAR agonism). These agents dovetail the clinical and trial experience for off-label bezafibrate and fenofibrate use. Symptom management is essential, and encouragingly, PPAR agonists reduce itch; IBAT inhibition (eg, linerixibat) also appears promising for pruritus. For those where liver fibrosis is the target, NOX inhibition is being evaluated. Earlier stage therapies in development include therapy to impact immunoregulation in patients, as well other approaches to treating pruritus (eg, antagonists of MrgprX4). Collectively the PBC therapeutic landscape is exciting. Therapy goals are increasingly proactive and individualized and aspire to rapidly achieve normal serum tests and quality of life with prevention of end-stage liver disease.

Frailty in Patients with Chronic Graft-versus-Host Disease

Frailty is an increasingly recognized clinical diagnosis associated with high risk of disability and mortality. Frailty in patients after hematopoietic cell transplantation (HCT) is associated with increased nonrelapse mortality (NRM) and decreased overall survival (OS). Frailty has not been studied extensively in patients with chronic graft-versus-host disease (cGVHD). The objectives of the present study were to assess the prevalence and clinical correlates of frailty and the association of frailty with NRM and OS in patients enrolled in the Chronic GVHD Consortium. Patients were characterized as frail if they met the Fried definition of ≥3 of the following criteria at enrollment: unintentional weight loss, exhaustion, slow walking speed, low physical activity, and weakness. Frailty was assessed retrospectively using surrogate measures for the 5 domains of frailty. Frailty, cGVHD organ scores, and patient-reported outcomes were measured at the time of enrollment. The study included 399 patients from 9 centers in the United States, with 32% characterized as frail and 68% as not frail. The median duration of follow-up from enrollment was 9 years (interquartile range, 7 to 11 years). Frail patients were more likely to be older (P = .004), to have a lower Karnofsky Performance Status (P < .001), to have severe cGVHD (P < .001), and to have gastrointestinal (P < .001), liver (P = .04), or lung cGVHD (P = .002). In a multivariable analysis, older age, increased cGVHD global severity, and thrombocytopenia were statistically significantly associated with frailty when cGVHD organ involvement was excluded. A separate analysis excluding cGVHD severity and including organ involvement showed that lung and liver cGVHD and older age were associated with frailty. Neither corticosteroid use at the time of enrollment nor the maximum recorded dose of corticosteroids before enrollment was associated with frailty. Frail patients had higher NRM than nonfrail patients (P < .001), with a 10-year cumulative incidence of 41% (95% confidence interval [CI], 32% to 49%) versus 22% (95% CI, 17% to 28%). Reciprocally, frailty also was associated with a significantly lower OS (P < .001), with a 10-year OS of 43% (95% CI, 35% to 53%) in frail patients versus 63% (95% CI, 57% to 69%) in nonfrail patients. In multivariable analysis that included the individual domains of frailty, weakness, low physical activity, and slow walking speed were associated with survival. Frail patients also had worse scores on various measures of patient-reported outcomes, including the Short Form (SF)-36, the Lee Symptom Scale, and the trial outcome of the Functional Assessment of Cancer Therapy-Bone Marrow Transplantation (FACT-BMT) index score. Frail patients with cGVHD have significantly worse outcomes than nonfrail patients. Such clinical features as older age and lung and liver cGVHD are associated with frailty. Earlier clinical recognition of frailty in patients with cGVHD may prompt interventions to counteract frailty that could be beneficial for this population.

Neurosteroid Activation of GABA-A Receptors: A Potential Treatment Target for Symptoms in Primary Biliary Cholangitis?

BACKGROUND AND AIMS

A third of patients with primary biliary cholangitis (PBC) experience poorly understood cognitive symptoms, with a significant impact on quality of life (QOL), and no effective medical treatment. Allopregnanolone, a neurosteroid, is a positive allosteric modulator of gamma-aminobutyricacid-A (GABA-A) receptors, associated with disordered mood, cognition, and memory. This study explored associations between allopregnanolone and a disease-specific QOL scoring system (PBC-40) in PBC patients.

METHOD

Serum allopregnanolone levels were measured in 120 phenotyped PBC patients and 40 age and gender-matched healthy controls. PBC subjects completed the PBC-40 at recruitment. Serum allopregnanolone levels were compared across PBC-40 domains for those with none/mild symptoms versus severe symptoms.

RESULTS

There were no overall differences in allopregnanolone levels between healthy controls (median = 0.03 ng/ml (IQR = 0.025)) and PBC patients (0.031 (0.42), p = 0.42). Within the PBC cohort, higher allopregnanolone levels were observed in younger patients (r (120) = -0.53, p < 0.001) but not healthy controls (r (39) = -0.21, p = 0.21). Allopregnanolone levels were elevated in the PBC-40 domains, cognition (u = 1034, p = 0.02), emotional (u = 1374, p = 0.004), and itch (u = 795, p = 0.03). Severe cognitive symptoms associated with a younger age: severe (50 (12)) vs. none (60 (13); u = 423 p = 0.001).

CONCLUSION

Elevated serum allopregnanolone is associated with severe cognitive, emotional, and itch symptoms in PBC, in keeping with its known action on GABA-A receptors. Existing novel compounds targeting allopregnanolone could offer new therapies in severely symptomatic PBC, satisfying a significant unmet need.

Linking Human Betaretrovirus with Autoimmunity and Liver Disease in Patients with Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by the production of diagnostic antimitochondrial antibodies (AMA) reactive to the pyruvate dehydrogenase complex. A human betaretrovirus (HBRV) resembling mouse mammary tumor virus has been characterized in patients with PBC. However, linking the viral infection with the disease is not a straight-forward process because PBC is a complex multifactorial disease influenced by genetic, hormonal, autoimmune, environmental, and other factors. Currently, PBC is assumed to have an autoimmune etiology, but the evidence is lacking to support this conjecture. In this review, we describe different approaches connecting HBRV with PBC. Initially, we used co-cultivation of HBRV with biliary epithelial cells to trigger the PBC-specific phenotype with cell surface expression of cryptic mitochondrial autoantigens linked with antimitochondrial antibody expression. Subsequently, we have derived layers of proof to support the role of betaretrovirus infection in mouse models of autoimmune biliary disease with spontaneous AMA production and in patients with PBC. Using Hill’s criteria, we provide an overview of how betaretrovirus infection may trigger autoimmunity and propagate biliary disease. Ultimately, the demonstration that disease can be cured with antiviral therapy may sway the argument toward an infectious disease etiology in an analogous fashion that was used to link H. pylori with peptic ulcer disease.

Understanding fatigue in primary biliary cholangitis: From pathophysiology to treatment perspectives

Fatigue is considered one of the most frequent and debilitating symptoms in primary biliary cholangitis (PBC), affecting over 50% of PBC patients. One in five patients with PBC suffer from severe fatigue, which significantly impairs quality of life. Fatigue is made up of a central and a peripheral component, whose pathophysiology is still greatly unresolved. Central fatigue is characterised by a lack of self-motivation and can manifest both in physical and mental activities (lack of intention). Peripheral fatigue includes neuromuscular dysfunction and muscle weakness (lack of ability). Peripheral fatigue could be explained by an excessive deviation from aerobic to anaerobic metabolism leading to excessive lactic acid accumulation and therefore accelerated decline in muscle function and prolonged recovery time. As opposed to itching, and with the exception of end-stage liver disease, fatigue is not related to disease progression. The objective of this review is to outline current understanding regarding the pathophysiology of fatigue, the role of comorbidities and contributing factors, the main tools for fatigue assessment, the failed therapeutic options, and future treatment perspectives for this disabling symptom. Since fatigue is an extremely common and debilitating symptom and there is still no licensed therapy for fatigue in PBC patients, further research is warranted to understand its causative mechanisms and to find an effective treatment.

Understanding Fatigue in Primary Biliary Cholangitis

BACKGROUND

Fatigue affects 50% of primary biliary cholangitis patients and is severe in approximately 20%, significantly affecting quality of life. The pathogenesis of fatigue in primary biliary cholangitis is poorly understood. This study aimed to explore subgroups of fatigue to support targeting of selected groups in future clinical trials.

METHODS

Data were derived from the UK-PBC cohort. Participants completed the PBC-40, Hospital Anxiety and Depression Score, Epworth Sleepiness Scale, and Orthostatic Grading Scale for symptoms assessment. Fatigue and cognitive symptoms were regarded as clinically significant if they exceeded the previously defined cutoff for "moderate" symptom.

RESULTS

Of 2002, patients for whom full PBC-40, fatigue, and cognitive symptom domain scores were available, 1203 (60%) had significant fatigue and 730 (36%) had significant cognitive symptoms. Among the 1203 patients with significant fatigue, 663 (55%) also had significant cognitive symptoms (termed fatigue with cognitive symptoms) with a significant linear association between the fatigue and cognitive symptom severity. "Fatigue with cognitive symptoms" patients were younger and more likely to have severe fatigue. They also experienced greater social and emotional impact.

CONCLUSIONS

Fatigue in PBC is complex, and there has been no progress to date in identifying therapies able to improve it. One factor in slow progress may be the heterogeneity of patients describing fatigue complicating effective cohort selection for clinical trials. This study has identified potential discrete subgroups of fatigued patients with and without cognitive symptoms. The group of patients expressing "fatigue with cognitive symptoms" was homogenous and may represent a coherent cohort for clinical trials.

Home-based exercise in patients with refractory fatigue associated with primary biliary cholangitis: a protocol for the EXerCise Intervention in cholesTatic LivEr Disease (EXCITED) feasibility trial

INTRODUCTION

Fatigue is the most commonly reported symptom of the liver disease primary biliary cholangitis (PBC). It affects 40%-80% of patients, has no effective treatment and is associated with heightened mortality risk. The pathogenesis is unknown, but muscle bioenergetic abnormalities have been proposed to contribute. Directly observed exercise has been shown to attenuate symptoms in small groups; however, due to the rare nature of the disease, home-based interventions need to be evaluated for feasibility, safety and efficacy.

METHODS AND ANALYSIS

This is a phase 1/pilot, single-arm, open-label clinical trial evaluating a novel home-based exercise programme in patients with PBC with severe fatigue. Forty patients with moderate-severe fatigue (PBC40 fatigue domain score >33; other causes of fatigue excluded) will be selected using a convenience sampling method. A 12-week home-based exercise programme, consisting of individualised resistance, aerobic exercises and telephone health calls (first 6 weeks only), will be delivered. Measures of fatigue (PBC40 fatigue domain; fatigue impact scale), quality of life, sleep (Epworth Sleep Score), physical activity, anxiety and depression, aerobic exercise capacity (incremental shuttle walk test; Duke Activity Status Index) and functional capacity (short physical performance battery) will be assessed at baseline and at 6 and 12 weeks following the intervention.

ETHICS AND DISSEMINATION

The protocol is approved by the National Research Ethics Service Committee London (IRAS 253115). Recruitment commenced in April 2019 and ended in March 2020. Participant follow-up is due to finish by December 2020. Findings will be disseminated through peer-reviewed publication, conference presentation and social media.

TRIAL REGISTRATION NUMBER

NCT04265235.

Update on Emerging Treatment Options for Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a rare autoimmune cholestatic liver disease that may progress to fibrosis or cirrhosis. Treatment options are currently limited. Ursodeoxycholic acid (UDCA) remains first-line therapy and has been proven to normalize serum biochemistries, halt histologic disease progression, and lead to patient survival comparable to the general population. Obeticholic acid (OCA) was recently approved as adjunct therapy in PBC patients with inadequate response or intolerance to UDCA. However, OCA has been associated with worsening pruritus in clinical studies which may limit its use in this patient population. Several studies are currently underway to address the lack of treatment options for PBC. Of these, fibrates, which have been used in Japan for over a decade, have produced promising results. Furthermore, as currently approved therapies for PBC do not address the potentially debilitating clinical symptoms of PBC such as pruritus and fatigue, supplemental therapy is often required for symptom control.

Exercise and physical activity in cirrhosis: opportunities or perils

Reduced exercise capacity and impaired physical performance are observed in nearly all patients with liver cirrhosis. Physical activity and exercise are physiological anabolic stimuli that can reverse dysregulated protein homeostasis or proteostasis and potentially increase muscle mass and contractile function in healthy subjects. Cirrhosis is a state of anabolic resistance, and unlike the beneficial responses to exercise reported in physiological states, there are few systematic studies evaluating the response to exercise in cirrhosis. Hyperammonemia is a mediator of the liver-muscle axis with net skeletal muscle ammonia uptake in cirrhosis causing signaling perturbations, mitochondrial dysfunction with decreased ATP content, modifications of contractile proteins, and impaired ribosomal function, all of which contribute to anabolic resistance in cirrhosis and have the potential to impair the beneficial responses to exercise. English language-publications in peer-reviewed journals that specifically evaluated the impact of exercise in cirrhosis were reviewed. Most studies evaluated responses to endurance exercise, and readouts included peak or maximum oxygen utilization, grip strength, and functional capacity. Endurance exercise for up to 12 wk is clinically tolerated in well-compensated cirrhosis. Data on the safety of resistance exercise are conflicting. Nutritional supplements enhance the benefits of exercise in healthy subjects but have not been evaluated in cirrhosis. Whether the beneficial physiological responses with endurance exercise and increase in muscle mass with resistance exercise that occur in healthy subjects also occur in cirrhotics is not known. Specific organ-system responses, changes in body composition, or improved long-term clinical outcomes with exercise in cirrhosis need evaluation.

Rituximab Is Ineffective for Treatment of Fatigue in Primary Biliary Cholangitis: A Phase 2 Randomized Controlled Trial

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease. Half of patients experience debilitating fatigue, which is currently untreatable. Previous studies have shown muscle bioenergetic abnormalities in PBC, including increased muscle acidosis with exercise linked to the antimitochondrial antibody (AMA) diagnostic of the disease, and reduced anaerobic threshold. In this study we addressed the hypothesis that fatigue in PBC is driven by muscle bioenergetic abnormality related to AMA, and that AMA reduction with B-cell depletion therapy will improve fatigue. In our single-center phase 2 randomized controlled trial, 57 participants aged 18 years or older with PBC and moderate to severe fatigue were randomized to receive two doses of either rituximab (1000 mg) or saline (placebo). The primary outcome measure was fatigue severity assessed using the PBC-40 fatigue domain at 3 months. Secondary outcome measures included patient-reported outcomes and immunological and bioenergetics disease parameters. Experimental outcomes included biochemical markers of disease severity. Improvement in fatigue score at 3 months was seen in both arms, with no significant difference (adjusted mean difference -0.9 [95% confidence interval -4.6 to 3.1]). Little difference was observed in other patient-reported outcomes or physical activity. Significant anaerobic threshold improvement was seen in the rituximab group, only but this was not associated with fatigue improvement. No treatment-emergent serious adverse events were seen. Conclusions: Rituximab was safe over the 12-month study period but showed no evidence of effectiveness for the treatment of fatigue in PBC. Anaerobic threshold improvement was seen, potentially linking AMA with muscle bioenergetics dysfunction; however, this was not related to improvement in fatigue. Rituximab had some evidence of a beneficial effect on alkaline phosphatase levels in this largely ursodeoxycholic acid (UDCA)-responding, early-disease stage cohort. (Hepatology 2018; 00:000-000).

Treatment of Fatigue in Primary Biliary Cholangitis: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Fatigue is the most common complication of primary biliary cholangitis (PBC) and can be debilitating. Numerous interventions have been trialed targeting several proposed mechanisms of PBC-associated fatigue. We sought to summarize and perform a meta-analysis to determine the efficacy of these interventions.

METHODS

A comprehensive database search was conducted from inception through March 27, 2018. The primary outcome was proportion of fatigued patients or reduction in degree of fatigue. Adverse events were a secondary outcome. We assessed studies for risk of bias, graded quality of evidence, and used meta-analysis to obtain overall effect by pooling studies of the same class.

RESULTS

We identified 16 studies evaluating ursodeoxycholic acid (UDCA) (7), liver transplantation (2), serotonin reuptake inhibitors (2), colchicine (1), methotrexate (1), cyclosporine (1), modafinil (1), and obeticholic acid (1). On meta-analysis, UDCA was not associated with a reduction in risk of fatigue (RR = 0.86, 95% CI 0.69-1.08, p = 0.19, I² = 56.2%). While liver transplantation did reduce degree of fatigue (SMD - 0.57, 95% CI - 0.89 to - 0.24, p = 0.001, I² = 67.3%), fatigue did not return to baseline indicating the underlying cause may not be addressed.

CONCLUSIONS

While there is some improvement in fatigue with liver transplantation, there is a lack of high-quality evidence supporting the efficacy of any other intervention in the treatment of PBC-related fatigue. Further research into the underlying pathophysiology may help guide future trials.

Muscle performance and fatigue in compensated chronic liver disease

Background: A common and debilitating symptom in patients with chronic liver disease is fatigue (CLD). Muscle dysfunction has been suggested to be a key mechanism of fatigue in CLD. Objective: We aimed to evaluate fatigue and the potential association with muscle performance and physical activity in outpatients with CLD. Methods: Two-hundred seventy outpatients with CLD were included, (52 ± 15 years, mean ± SD; 151 females) with autoimmune hepatitis (n = 49), primary biliary cholangitis (n = 45), primary sclerosing cholangitis (n = 46), chronic hepatitis B (n = 57) or C (n = 73). Patients with a Child-Pugh >6 were excluded. The questionnaire Fatigue Impact Scale (FIS) was used to evaluate fatigue, and physical activity was evaluated through a self-reported level of physical activity. Muscle function was assessed with four muscle tests, walking speed, handgrip strength, standing heel-rise test (SHT) and 'Timed Up and Go' test (TUG). Results: The median total FIS score was 30 (40% had FIS > 40, considered high-fatigue). Diminished muscle performance was observed in the SHT (% of predicted value: 53 ± 26%) and with maximum grip strength (85 ± 20%). The FIS score was significantly different between groups of CLDs (p = .004). In multivariate analysis the TUG (p = .001), SHT (p = .005), antidepressants (p < .001), and level of physical activity (p = .001) were associated with fatigue (R² = 29%). Subjects with higher levels of physical activity had lower FIS (p < .001). Conclusions: In patients with CLD, fatigue was associated with low muscle performance and reduced level of physical activity, which could be a potential therapeutic target.

Fatigue in chronic liver disease: New insights and therapeutic approaches

The management of fatigue associated with chronic liver disease is a complex and major clinical challenge. Although fatigue can complicate many chronic diseases, it is particularly common in diseases with an inflammatory component. Fatigue can have both peripheral (i.e., neuromuscular) and central (i.e., resulting from changes in neurotransmission within the brain) causes. However, fatigue in chronic liver disease has strong social/contextual components and is often associated with behavioural alterations including depression and anxiety. Given the increasing awareness of patient-reported outcomes as important components of treatment outcomes and clinical research, there is a growing need to better understand and manage this poorly understood yet debilitating symptom. Although several pathophysiological mechanisms for explaining the development of fatigue have been generated, our understanding of fatigue in patients with chronic liver disease remains incomplete. A better understanding of the pathways and neurotransmitter systems involved may provide specific directed therapies. Currently, the management of fatigue in chronic liver disease can involve a combined use of methods to beneficially alter behavioural components and pharmacological interventions, of which several treatments have potential for the improved management of fatigue in chronic liver disease. However, evidence and consensus are lacking on the best approach and the most appropriate biochemical target(s) whilst clinical trials to address this issue have been few and limited by small sample size. In this review, we outline current understanding of the impact of fatigue and related symptoms in chronic liver disease, discuss theories of pathogenesis, and examine current and emerging approaches to its treatment.

Physical exercise for people with cirrhosis

BACKGROUND

Loss of muscle mass and muscle weakness are common complications to cirrhosis and are associated with increased morbidity and mortality. Therefore, physical exercise may benefit people with cirrhosis.

OBJECTIVES

To assess the beneficial and harmful effects of physical exercise versus sham exercise or no exercise for people with cirrhosis.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, and three other databases, including manual searches through reference lists, abstracts, and presentations at conferences and meetings, Google Scholar, and online trial registers in February 2018.

SELECTION CRITERIA

We included randomised clinical trials regardless of publication status or language. Inclusion criteria were cirrhosis irrespective of the aetiology or stage. Interventions were physical exercise compared with sham exercise or no intervention.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data. We undertook meta-analyses and presented results using risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, both with 95% confidence intervals (CI) and I² values as markers of imprecision and heterogeneity. We assessed bias control using the Cochrane Hepato-Biliary Group domains and determined the credibility of the evidence using GRADE.

MAIN RESULTS

We included six randomised clinical trials with 173 participants. All participants had Child-Pugh stage A or B cirrhosis. The intervention groups participated in eight to 14 weeks of physical exercise (aerobic: three trials; resistance: one trial; or aerobic plus resistance training: two trials). Control groups underwent sham exercise (supervised relaxation: one trial) or no intervention (five trials). None of the 89 participants allocated to exercise versus two of 84 participants in the control group died (RR 0.19, 95% CI 0.01 to 3.73; moderate-quality evidence). The cause of death was acute-on-chronic liver disease for both participants. Nine participants in the exercise group and 13 in the control group experienced serious adverse events (RR 0.61, 95% CI 0.19 to 1.94; low-quality evidence).Physical exercise showed no beneficial or detrimental effect on health-related quality of life assessed by the Chronic Liver Disease Questionnaire (MD 0.11, 95% CI -0.44 to 0.67; low-quality evidence). Likewise, physical exercise had no clear effect on physical fitness measured by peak exercise oxygen uptake (MD 0.3 mL/kg/minute, 95 % CI -2.74 to 3.35; low-quality evidence) and Six-Minute Walk Test (MD 56.06 min, 95% CI -9.14 to 121.26; very low-quality evidence). Physical exercise showed no clear effect on mid-thigh circumference (MD 1.76 cm, 95% CI -0.26 to 3.77; low-quality evidence), but showed an increase in mid-arm circumference (MD 2.61 cm, 95% CI 0.36 to 4.85; low-quality evidence).

AUTHORS' CONCLUSIONS

We found no clear beneficial or harmful effect of physical exercise on mortality, morbidity, or health-related quality of life. Further evidence is needed to evaluate the beneficial and harmful effects of physical exercise on clinical outcomes.

The British Society of Gastroenterology/UK-PBC primary biliary cholangitis treatment and management guidelines

Primary biliary cholangitis (formerly known as primary biliary cirrhosis, PBC) is an autoimmune liver disease in which a cycle of immune mediated biliary epithelial cell injury, cholestasis and progressive fibrosis can culminate over time in an end-stage biliary cirrhosis. Both genetic and environmental influences are presumed relevant to disease initiation. PBC is most prevalent in women and those over the age of 50, but a spectrum of disease is recognised in adult patients globally; male sex, younger age at onset (<45) and advanced disease at presentation are baseline predictors of poorer outcome. As the disease is increasingly diagnosed through the combination of cholestatic serum liver tests and the presence of antimitochondrial antibodies, most presenting patients are not cirrhotic and the term cholangitis is more accurate. Disease course is frequently accompanied by symptoms that can be burdensome for patients, and management of patients with PBC must address, in a life-long manner, both disease progression and symptom burden. Licensed therapies include ursodeoxycholic acid (UDCA) and obeticholic acid (OCA), alongside experimental new and re-purposed agents. Disease management focuses on initiation of UDCA for all patients and risk stratification based on baseline and on-treatment factors, including in particular the response to treatment. Those intolerant of treatment with UDCA or those with high-risk disease as evidenced by UDCA treatment failure (frequently reflected in trial and clinical practice as an alkaline phosphatase >1.67 × upper limit of normal and/or elevated bilirubin) should be considered for second-line therapy, of which OCA is the only currently licensed National Institute for Health and Care Excellence recommended agent. Follow-up of patients is life-long and must address treatment of the disease and management of associated symptoms.

Complications, symptoms, quality of life and pregnancy in cholestatic liver disease

Cholestatic liver diseases (CLDs) encompass a variety of disorders of bile formation and/or flow which generally result in progressive hepatobiliary injury and ultimately end-stage liver disease. Many patients with CLD are diagnosed between the ages of 20-50 years, a particularly productive period of life professionally, biologically and in other respects; it is not surprising, thus, that CLD is often associated with impaired health-related quality of life (HRQOL) and uncertainty regarding implications for and outcomes of pregnancy. Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are the most prominent CLDs, both having considerable morbidity and mortality and representing major indications for liver transplantation. These disorders, as a consequence of their complications (eg ascites, hepatic osteodystrophy), associated conditions (eg inflammatory bowel disease) and symptoms (eg pruritus and fatigue), can significantly impair an array of domains of HRQOL. Here we review these impactful clinical aspects of PSC and PBC as well as the topics of fertility and pregnancy.

EASL Clinical Practice Guidelines: The diagnosis and management of patients with primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic inflammatory autoimmune cholestatic liver disease, which when untreated will culminate in end-stage biliary cirrhosis. Diagnosis is usually based on the presence of serum liver tests indicative of a cholestatic hepatitis in association with circulating antimitochondrial antibodies. Patient presentation and course can be diverse and risk stratification is important to ensure all patients receive a personalised approach to their care. The goals of treatment and management are the prevention of end-stage liver disease, and the amelioration of associated symptoms. Pharmacologic approaches in practice, to reduce the impact of the progressive nature of disease, currently include licensed therapies (ursodeoxycholic acid and obeticholic acid) and off-label therapies (fibric acid derivatives, budesonide). These clinical practice guidelines summarise the evidence for the importance of a structured, life-long and individualised, approach to the care of patients with PBC, providing a framework to help clinicians diagnose and effectively manage patients.

Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy/chronic fatigue syndrome

Myalgic encephalopathy/chronic fatigue syndrome (ME/CFS) is a debilitating disease of unknown etiology, with hallmark symptoms including postexertional malaise and poor recovery. Metabolic dysfunction is a plausible contributing factor. We hypothesized that changes in serum amino acids may disclose specific defects in energy metabolism in ME/CFS. Analysis in 200 ME/CFS patients and 102 healthy individuals showed a specific reduction of amino acids that fuel oxidative metabolism via the TCA cycle, mainly in female ME/CFS patients. Serum 3-methylhistidine, a marker of endogenous protein catabolism, was significantly increased in male patients. The amino acid pattern suggested functional impairment of pyruvate dehydrogenase (PDH), supported by increased mRNA expression of the inhibitory PDH kinases 1, 2, and 4; sirtuin 4; and PPARδ in peripheral blood mononuclear cells from both sexes. Myoblasts grown in presence of serum from patients with severe ME/CFS showed metabolic adaptations, including increased mitochondrial respiration and excessive lactate secretion. The amino acid changes could not be explained by symptom severity, disease duration, age, BMI, or physical activity level among patients. These findings are in agreement with the clinical disease presentation of ME/CFS, with inadequate ATP generation by oxidative phosphorylation and excessive lactate generation upon exertion.

Physical activity and liver diseases

Regular physical activity beneficially impacts the risk of onset and progression of several chronic diseases. However, research regarding the effects of exercising on chronic liver diseases is relatively recent. Most researchers focused on nonalcoholic fatty liver disease (NAFLD), in which increasing clinical and experimental data indicate that skeletal muscle crosstalking to the adipose tissue and the liver regulates intrahepatic fat storage. In this setting, physical activity is considered to be required in combination with calories restriction to allow an effective decrease of intrahepatic lipid component, and despite that evidence is not conclusive, some studies suggest that vigorous activity might be more beneficial than moderate activity to improve NAFLD/nonalcoholic steatohepatitis. Evidence regarding the effects of exercise on the risk of hepatocellular carcinoma is scarce; some epidemiological studies indicate a lower risk in patients regularly and vigorously exercising. In compensated cirrhosis, exercise acutely increases portal pressure, but in the longer term it has been proved safe and probably beneficial. Decreased aerobic capacity (VO2 ) correlates with mortality in patients with decompensated cirrhosis, who are almost invariably sarcopenic. In these patients, VO2 is improved by physical activity, which might also reduce the risk of hepatic encephalopathy through an increase in skeletal muscle mass. In solid organ transplantation recipients, exercise is able to improve lean mass, muscle strength, and, as a consequence, aerobic capacity. Few data exist in liver transplant recipients, in whom exercise should be an object of future studies given its high potential of providing long-term beneficial effects.

CONCLUSIONS

Despite that evidence is far from complete, physical activity should be seen as an important part of the management of patients with liver disease in order to improve their clinical outcome.

Understanding Muscle Dysfunction in Chronic Fatigue Syndrome

Introduction. Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a debilitating disorder of unknown aetiology, characterised by severe disabling fatigue in the absence of alternative diagnosis. Historically, there has been a tendency to draw psychological explanations for the origin of fatigue; however, this model is at odds with findings that fatigue and accompanying symptoms may be explained by central and peripheral pathophysiological mechanisms, including effects of the immune, oxidative, mitochondrial, and neuronal pathways. For example, patient descriptions of their fatigue regularly cite difficulty in maintaining muscle activity due to perceived lack of energy. This narrative review examined the literature for evidence of biochemical dysfunction in CFS/ME at the skeletal muscle level. Methods. Literature was examined following searches of PUB MED, MEDLINE, and Google Scholar, using key words such as CFS/ME, immune, autoimmune, mitochondria, muscle, and acidosis. Results. Studies show evidence for skeletal muscle biochemical abnormality in CFS/ME patients, particularly in relation to bioenergetic dysfunction. Discussion. Bioenergetic muscle dysfunction is evident in CFS/ME, with a tendency towards an overutilisation of the lactate dehydrogenase pathway following low-level exercise, in addition to slowed acid clearance after exercise. Potentially, these abnormalities may lead to the perception of severe fatigue in CFS/ME.

Understanding and Treating Fatigue in Primary Biliary Cirrhosis and Primary Sclerosing Cholangitis

Fatigue is a significant problem for patients with primary biliary cirrhosis and although experienced less by patients with primary sclerosing cholangitis, a minority still report significant fatigue. Fatigue is the symptom with the greatest impact on quality of life, particularly when associated with social dysfunction. The pathogenesis of fatigue in cholestatic liver disease is complex, poorly understood, and probably has central and peripheral components. Managing fatigue in cholestatic liver disease presents a challenge for clinicians given the complexity and its numerous associations. This article presents a structured approach to managing fatigue in cholestatic liver disease to improve fatigue severity and quality of life.

RITPBC: B-cell depleting therapy (rituximab) as a treatment for fatigue in primary biliary cirrhosis: study protocol for a randomised controlled trial

INTRODUCTION

Primary biliary cirrhosis (PBC) is an autoimmune liver disease with approximately 50% of patients experiencing fatigue. This can be a particularly debilitating symptom, affecting quality of life and resulting in social isolation. Fatigue is highlighted by patients as a priority for research and patient support groups were involved in designing this trial. This is the first randomised controlled trial to investigate a treatment for fatigue in PBC. The trial protocol is innovative as it utilises novel magnetic resonance spectroscopy (MRS) techniques as an outcome measure. The protocol will be valuable to research groups planning clinical trials targeting fatigue in PBC and also transferrable to other conditions associated with fatigue.

METHODS AND ANALYSIS

RITPBC is a Medical Research Council (MRC) and National Institute for Health Research (NIHR) Efficacy and Mechanism Evaluation Programme (EME)-funded project. It is a phase II, single-centre, randomised controlled, double-blinded trial comparing rituximab with placebo in fatigued PBC patients. 78 patients with PBC and moderate to severe fatigue will be randomised to receive two infusions of rituximab or placebo. The study aims to assess whether rituximab improves fatigue in patients with PBC, the safety, and tolerability of rituximab in PBC and the sustainability of any beneficial actions. The primary outcome will be an improvement in fatigue domain score of the PBC-40, a disease-specific quality of life measure, evaluated at 12-week assessment. Secondary outcome measures include novel MRS techniques assessing muscle bioenergetic function, physical activity, anaerobic threshold and symptom, and quality of life measures. The trial started recruiting in October 2012 and recruitment is ongoing.

ETHICS AND DISSEMINATION

The trial has ethical approval from the NRES Committee North East, has Clinical Trial Authorisation from MHRA and local R&D approval. Trial results will be communicated to participants, presented at national and international meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN03978701.

Primary biliary cirrhosis: safety and benefits of established and emerging therapies

INTRODUCTION

Primary biliary cirrhosis (PBC) is a chronic, cholestatic liver disease characterized histologically by lymphocytic cholangitis and intralobular bile duct destruction. It is a progressive disorder associated with increased mortality and decreased quality of life related to hepatic fibrosis, troublesome symptoms such as fatigue and pruritus, and ultimately endstage cirrhosis. PBC affects adults around the world, and therefore effective treatment of PBC and its associated symptoms constitute significant issues for patients and providers as well as on a public health level. The only approved pharmacotherapy for PBC to date is ursodeoxycholic acid (UDCA), a choleretic, hydrophilic bile acid which has been in clinical use for decades. UDCA is effective in a majority of patients with PBC, but nearly a third of patients are UDCA non-responders. Non-response to UDCA is associated with an increased risk of death or need for liver transplantation (LT). Whereas LT is an effective treatment, it engenders substantial cost and a risk of PBC recurrence, among other complications. Patients who are non-responders to UDCA or have highly symptomatic disease (e.g., intractable pruritus) are thus in critical need of novel therapeutic approaches, which are both safe and effective.

AREAS COVERED

In this review, we provide a synopsis regarding the safety and benefits of established and emerging pharmacotherapies for PBC and present viewpoints on how they may evolve over the next several years.

EXPERT OPINION

It is our belief that the pharmacoscope of PBC, as with other cholestatic liver diseases, is likely to see important advancements in the near future.

Pathogenesis of primary biliary cirrhosis and its fatigue

Primary biliary cirrhosis (PBC) is an autoimmune cholestatic liver disease characterised by a breakdown of immune tolerance to mitochondrial and nuclear antigens, causing injury to the biliary epithelial cells (BEC) lining the small intrahepatic bile ducts. This leads to bile duct injury and the retention of hydrophobic bile acids which cause further BEC injury leading to a self-sustaining cycle of bile duct injury. Initially the BEC respond to injury via a homeostatic response including through proliferation. Ultimately they become senescent; an active process with accompanying release of inflammatory cytokines ('the senescent secretome') which contributes to the process of interface hepatitis which is a feature of high-risk and treatment-unresponsive disease. This model for pathogenesis of PBC has implications for potential therapy approaches in targeting both the 'upstream' immune injury and 'downstream' BEC response to the immune injury. Fatigue is the commonest reported symptom in PBC and has a negative impact on patients' perceived quality of life, often through social isolation. It is unrelated to the severity of liver disease and appears unresponsive to current therapies, including ursodeoxycholic acid and transplantation. Fatigue in PBC is complex, with numerous associated peripheral and CNS features. Initially, cholestasis causes degenerative CNS change affecting areas of the brain regulating autonomic dysfunction and sleep, and these changes lead directly to some manifestations of fatigue and the associated cognitive impairment. In addition to this, the anti-mitochondrial antibody has direct muscle level metabolic effects leading to over-utilisation of anaerobic metabolism. Autonomic dysfunction contributes to the impact of this metabolic change by limiting the capacity of the muscle to respond through increased proton/lactate efflux from cells and outflow from tissues. The model has a number of implications for potential therapy approaches.

The impact of liver transplantation on the phenotype of primary biliary cirrhosis patients in the UK-PBC cohort

BACKGROUND & AIMS

Liver transplantation improves survival in end-stage primary biliary cirrhosis (PBC), but the benefit for systemic symptoms including fatigue is less clear. The aim of this study was to utilise the comprehensive UK-PBC Research Cohort, including 380 post-transplant patients and 2300 non-transplanted patients, to answer key questions regarding transplantation for PBC.

METHODS

Cross-sectional study of post-transplant PBC patients and case-matched non-transplanted patients. Detailed clinical information was collected, together with patient systemic symptom impact data using validated assessment tools.

RESULTS

Over 25% of patients in the transplant cohort were grafted within 2 years of PBC diagnosis suggesting advanced disease at presentation. Transplanted patients were significantly younger at presentation than non-transplanted (mean 7 years) and >35% of all patients in the UK-PBC cohort who presented under 50 years had already undergone liver transplantation at the study censor point (>50% were treatment failures (post-transplant or unresponsive to UDCA)). Systemic symptom severity (fatigue and cognitive symptoms) was identical in female post-transplant patients and matched non-transplanted controls and unrelated to disease recurrence or immunosuppression type. In males, symptoms were worse in transplanted than in non-transplanted patients.

CONCLUSIONS

Age at presentation is a major risk factor for progression to transplant (as well as UDCA non-response) in PBC. Although both confirmatory longitudinal studies, and studies utilising objective as well as subjective measures of function, are needed if we are to address the question definitively, we found no evidence of improved systemic symptoms after liver transplantation in PBC and patients should be advised accordingly. Consideration needs to be given to enhancing rehabilitation approaches to improve function and life quality after liver transplant for PBC.

HIV-associated fatigue in the era of highly active antiretroviral therapy: novel biological mechanisms?

OBJECTIVE

The aim of the study was to determine the prevalence and risk factors for HIV-associated fatigue in the era of highly active antiretroviral therapy (HAART).

METHODS

A cross-sectional survey of 100 stable HIV-infected out-patients was carried out. Severity of fatigue was measured using the Fatigue Impact Scale (FIS). Symptoms of orthostatic intolerance (dysautonomia) were evaluated using the Orthostatic Grading Scale (OGS). Data for HIV-infected patients were compared with those for 166 uninfected controls and 74 patients with chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (encephalopathy) (ME).

RESULTS

Ninety-one per cent of HIV-infected patients were on HAART and 78% had suppressed plasma HIV viral load (≤ 40 HIV-1 RNA copies/mL). Fifty-one per cent of HIV-infected patients reported excessive symptomatic fatigue (FIS ≥ 40), and 28% reported severe fatigue symptoms (FIS ≥ 80). The mean FIS score among HIV-infected patients was 50.8 [standard deviation (SD) 41.9] compared with 13.0 (SD 17.6) in uninfected control subjects, and 92.9 (SD 29.0) in CFS patients (P < 0.001 for comparison of HIV-infected patients and uninfected controls). Among HIV-infected patients, fatigue severity was not significantly associated with current or nadir CD4 lymphocyte count, HIV plasma viral load, or whether on HAART. Prior dideoxynucleoside analogue (d-drug) exposure (P = 0.016) and the presence of clinical lipodystrophy syndrome (P = 0.011) were associated with fatigue. Additionally, fatigue severity correlated strongly with symptomatic orthostatic intolerance (r = 0.65; P < 0.001).

CONCLUSIONS

Fatigue is very common and often severe in HIV-infected out-patients, despite viral suppression and good immune function. In a subgroup of patients, prior d-drug exposure may contribute to fatigue, suggesting a metabolic basis. Dysautonomia may also drive fatigue associated with HIV infection, as in other chronic diseases, and CFS/ME, and should be further evaluated with the potential for a shared therapeutic approach.

Loss of capacity to recover from acidosis on repeat exercise in chronic fatigue syndrome: a case-control study

BACKGROUND

Chronic fatigue syndrome (CFS) patients frequently describe difficulties with repeat exercise. Here, we explore muscle bioenergetic function in response to three bouts of exercise.

METHODS

A total of 18 CFS (CDC 1994) patients and 12 sedentary controls underwent assessment of maximal voluntary contraction (MVC), repeat exercise with magnetic resonance spectroscopy and cardio-respiratory fitness test to determine anaerobic threshold.

RESULT

Chronic fatigue syndrome patients undertaking MVC fell into two distinct groups: 8 (45%) showed normal PCr depletion in response to exercise at 35% of MVC (PCr depletion >33%; lower 95% CI for controls); 10 CFS patients had low PCr depletion (generating abnormally low MVC values). The CFS whole group exhibited significantly reduced anaerobic threshold, heart rate, VO(2) , VO(2) peak and peak work compared to controls. Resting muscle pH was similar in controls and both CFS patient groups. However, the CFS group achieving normal PCr depletion values showed increased intramuscular acidosis compared to controls after similar work after each of the three exercise periods with no apparent reduction in acidosis with repeat exercise of the type reported in normal subjects. This CFS group also exhibited significant prolongation (almost 4-fold) of the time taken for pH to recover to baseline.

CONCLUSION

When exercising to comparable levels to normal controls, CFS patients exhibit profound abnormality in bioenergetic function and response to it. Although exercise intervention is the logical treatment for patients showing acidosis, any trial must exclude subjects who do not initiate exercise as they will not benefit. This potentially explains previous mixed results in CFS exercise trials.

Managing systemic symptoms in chronic liver disease

Improved medical management and the changing disease demographic mean that the majority of patients with chronic liver disease are living with the disease rather than dying from it. Historically, the perception has been that the impact of chronic liver disease is related entirely to the consequences of endstage liver disease; however, more recently a number of systemic symptoms have been recognised that can occur at any point in the natural history of chronic liver disease and which can be associated with functional impairment and reduced quality of life. The most characteristic of these systemic symptoms is fatigue, which frequently associates with sleep disturbance and autonomic dysfunction, particularly manifest as abnormality of blood pressure regulation. Cognitive symptoms can occur even in non-cirrhotic patients. Falls can present in patients with autonomic dysfunction, complicated by the presence of peripheral muscle strength problems. Importantly for clinicians managing chronic liver disease, the severity of these systemic symptoms is typically not related to liver disease severity, and therefore despite optimal liver disease management, patients can often continue to experience debilitating symptoms. The similarity in systemic symptoms between different chronic liver diseases (and indeed chronic inflammatory conditions affecting other organs) suggests the possibility of shared pathogenetic processes and raises the possibility of common management strategies, although further research is urgently needed to confirm this. In primary biliary cirrhosis, where our understanding of systemic symptoms is arguably most developed, structured management strategies have been shown to improve the quality of life of patients. It is highly likely that similar approaches will have comparable benefits for other chronic liver disease groups. Here, we review the current understanding of systemic symptoms in chronic liver disease and offer recommendations regarding the successful management of these symptoms. Critical for successful treatment is use of a structured and systematic approach to management in which all contributing factors are addressed in an organised fashion. We believe that such a systematic approach, when applied to research as well as to clinical management, will allow us to reduce the overall burden of chronic liver disease, improve quality of life and enhance functional ability.

The monocarboxylate transporter family--role and regulation

Monocarboxylate transporter (MCT) isoforms 1-4 catalyze the proton-linked transport of monocarboxylates such as L-lactate across the plasma membrane, whereas MCT8 and MCT10 are thyroid hormone and aromatic amino acid transporters, respectively. The importance of MCTs is becoming increasingly evident as their extensive physiological and pathological roles are revealed. MCTs 1-4 play essential metabolic roles in most tissues with their distinct properties, expression profile, and subcellular localization matching the particular metabolic needs of a tissue. Important metabolic roles include energy metabolism in the brain, skeletal muscle, heart, tumor cells, and T-lymphocyte activation, gluconeogenesis in the liver and kidney, spermatogenesis, bowel metabolism of short-chain fatty acids, and drug transport. MCT8 is essential for thyroid hormone transport across the blood-brain barrier. Genetic perturbation of MCT function may be involved in disease states such as pancreatic β-cell malfunction (inappropriate MCT1 expression), chronic fatigue syndromes (impairment of muscle MCT function), and psychomotor retardation (MCT8 mutation). MCT expression can be regulated at both the transcriptional and post-transcriptional levels. Of particular importance is the upregulation of muscle MCT1 expression in response to training and MCT4 expression in response to hypoxia. The latter is mediated by hypoxia inducible factor 1α and often observed in tumor cells that rely almost entirely on glycolysis for their energy provision. The recent discovery of potent and specific MCT1 inhibitors that prevent proliferation of T-lymphocytes confirms that MCTs may be promising pharmacological targets including for cancer chemotherapy.

Functional capacity is significantly impaired in primary biliary cirrhosis and is related to orthostatic symptoms

OBJECTIVE

To assess patient-reported functional ability and its relationship with symptoms in primary biliary cirrhosis (PBC).

METHODS

Functional status was assessed in a representative cohort of 75 patients with PBC using the Patient-Reported Outcome Measure Information System Health-Assessment Questionnaire (PROMIS-HAQ) functional assessment tool and was related to both symptom severity at the point of assessment (assessed using the PBC-40 and Orthostatic Grading Scale) and symptom severity change over the previous 4 years. Functional status in the PBC group was compared with primary sclerosing cholangitis (cholestatic liver disease) and community controls.

RESULTS

Functional impairment at follow-up (PROMIS-HAQ) was substantial in PBC significantly higher than that in both primary sclerosing cholangitis and community controls. PROMIS-HAQ domain scores confirmed that patients with PBC had significant impairment in arising, eating, walking, reach and grip and activity, but not dressing or hygiene. Functional impairment correlated positively with greater PBC-40 Fatigue, Cognitive and Social and Emotional domains and higher orthostatic symptoms. Over 4 years, total symptom burden increased significantly (P=0.03). The predominant factor was rise in Cognitive domain scores indicating worsening cognitive symptoms (P<0.0001). Change in PBC-40 Cognitive, Social and Emotional scores (2005-2009) strongly predicted functional ability in 2009. Multivariate analysis confirmed that PROMIS-HAQ scores were predicted independently by PBC-40 Social and Emotional scores (P=0.02; β=0.3) and orthostatic symptoms (P=0.04; β=0.3).

CONCLUSION

PBC associates with substantial functional impairment. PBC symptom distribution evolves over time, with cognitive symptoms making ever-greater contribution to overall symptom burden. The major potentially modifiable determinant responsible for the functional impairment appears to be orthostatic symptoms.