Treatment of resistant pruritus from cholestasis with albumin dialysis: combined analysis of patients from three centers

Blood cytokine, chemokine and gene expression in cholestasis patients with intractable pruritis treated with a molecular adsorbent recirculating system: a case series

BACKGROUND

The molecular adsorbent recirculating system (MARS) is an albumin-dialysis modality that has been investigated predominantly in patients with acute and acute-on-chronic liver failure.

OBJECTIVES

To report the clinical efficacy and safety of MARS therapy for intractable pruritus in cholestasis patients with stable chronic liver disease, characterizing the impact of MARS on cytokine levels and on the transcriptome in the blood compartment.

METHODS

MARS therapy was performed on three patients with cholestatic liver disease using 8 h runs for two consecutive days. The expression levels of 65 cytokines⁄chemokines and 24,000 genes were profiled by Luminex (Luminex Corporation, USA) and microarray, respectively.

RESULTS

A quality-of-life assessment demonstrated a marked improvement during therapy, which was sustained in two of three patients. No bleeding or infectious complications were observed. Bile acid levels were markedly reduced following MARS (mean [± SD] pretreatment 478.9±112.2 µmol⁄L versus post-treatment 89.7±68.8 µmol⁄L). Concordant decreases in cytokine⁄chemokine levels were noted for interleukin (IL)-1beta, IL-2, IL-6, IL-8, IL-12 (p40), RANTES, tranforming growth factor-alpha, tumour necrosis factor-alpha and thrombopoietin following MARS. On microarray profiling, biologically relevant concordant changes among all patients were evident for 20 different genes (10 upregulated and 10 downregulated). The upregulation of several potentially immune suppressive⁄regulatory genes (eg, early growth response 3 [EGR-3], ephrin-A2 [EFNA2] and serum amyloid A1 [SAA1]), concurrent with downregulation of genes involved in innate immunity (eg, toll-like receptor 4 interactor with leucine-rich repeats [TRIL]) and inflammation (eg, ephrin receptor B1 [EPHB1]), was observed.

CONCLUSIONS

This investigative approach offers new insights into intractable pruritus and suggests future therapeutic targets. The clinical benefit of MARS in cholestasis patients with intractable pruritus may not exclusively result from filtration of pruritogens, but also from systemic changes in cytokine⁄chemokine levels and changes in gene expression of blood cells.

Bridging the gap: advances in artificial liver support

1. The goals of liver support therapy include the following: To provide detoxification and synthetic function during liver failure. To remove or reduce the production of proinflammatory cytokines to correct the systemic inflammatory response of liver failure. To stimulate the regeneration of the injured liver and increase the likelihood of spontaneous recovery. 2. There is a large unmet need for a liver support device because of the shortage of organs for liver transplantation and the risks of major surgery. 3. Liver support devices can be divided into 2 groups: purely mechanical artificial devices and cell-based bioartificial devices. Both provide detoxification, but bioartificial liver devices provide the option of synthetic function and biotransformation activities that are not possible with a purely mechanical device. 4. An abundant high-quality supply of human hepatocytes is not currently available for liver cell therapy. However, such a supply is essential for successful bioartificial liver therapy. Novel options are under development for the unlimited production of high-quality human hepatocytes.

Current pharmacotherapy for cholestatic liver disease

IMPORTANCE OF THE FIELD

The cholestatic liver diseases comprise a heterogeneous group of disorders which, left untreated, usually progresses to cirrhosis and liver failure. Most are recognized before the onset of advanced fibrosis, thereby affording an opportunity for disease modifying therapy.

AREAS COVERED

This review will cover the current pharmacologic management of the most common causes of cholestatic liver disease in adults, including primary biliary cirrhosis, primary biliary cirrhosis-autoimmune hepatitis overlap syndrome, primary sclerosing cholangitis, intrahepatic cholestasis of pregnancy, intestinal failure-associated liver disease, and immunoglobulin G4-associated cholangitis. Pharmacologic management of complications of cholestasis will also be reviewed.

EXPERT OPINION

Effective therapy for most cholestatic liver disease is lacking. Ursodeoxycholic acid (UDCA) slows the progression of primary biliary cirrhosis but the majority of patients do not have a full response. Even in those with a complete response, UDCA does not cure the disease. There is currently no effective medical therapy for primary sclerosing cholangitis. Symptoms and serum liver biochemistry values in intrahepatic cholestasis of pregnancy are improved with UDCA, but it is not certain if this alters the course of disease. Immunoglobulin G4-associated cholangitis is responsive to steroids but may relapse. The farnesoid X receptor agonists are a promising new class of drugs currently being tested in cholestatic liver disease.

Serum autotaxin is increased in pruritus of cholestasis, but not of other origin, and responds to therapeutic interventions

Pruritus is a seriously disabling symptom accompanying many cholestatic liver disorders. Recent experimental evidence implicated the lysophospholipase, autotaxin (ATX), and its product, lysophosphatidic acid (LPA), as potential mediators of cholestatic pruritus. In this study, we highlight that increased serum ATX levels are specific for pruritus of cholestasis, but not pruritus of uremia, Hodgkin's disease, or atopic dermatitis. Treatment of patients with cholestasis with the bile salt sequestrant, colesevelam, but not placebo, effectively reduced total serum bile salts and fibroblast growth factor 19 levels, but only marginally altered pruritus intensity and ATX activity. Rifampicin (RMP) significantly reduced itch intensity and ATX activity in patients with pruritus not responding to bile salt sequestrants. In vitro, RMP inhibited ATX expression in human HepG2 hepatoma cells and hepatoma cells overexpressing the pregnane X receptor (PXR), but not in hepatoma cells in which PXR was knocked down. Treatment of severe, refractory pruritus by the molecular adsorbents recirculation system or nasobiliary drainage improved itch intensity, which, again, correlated with the reduction of ATX levels. Upon reoccurrence of pruritus, ATX activity returned to pretreatment values.

CONCLUSION

Serum ATX activity is specifically increased in patients with cholestatic, but not other forms of, systemic pruritus and closely correlates with the effectiveness of therapeutic interventions. The beneficial antipruritic action of RMP may be explained, at least partly, by the PXR-dependent transcriptional inhibition of ATX expression. Thus, ATX likely represents a novel therapeutic target for pruritus of cholestasis.

Cholestasis-induced pruritus treated with ultraviolet B phototherapy: an observational case series study

BACKGROUND & AIMS

Pruritus is a disabling complication of cholestatic liver disorders. Its management remains challenging. Ultraviolet B (UVB) phototherapy has been successfully used to treat pruritus in other indications.

METHODS

This is an observational case series. The study population consists of 13 patients (10 females, mean age 52 years) with pruritus due to different cholestatic liver disorders: PBC (n=4), PSC (n=2), drug-induced (n=3) and persistent cholestasis after liver transplantation (LT) (n=4). Serum alkaline phosphatase levels were: 686 ± 363 μ/L and serum bile acids levels: 147 ± 15 μmol/L. In all patients, conventional medical treatment had failed to control pruritus. Perception of pruritus was recorded by the visual analogue scale (VAS).

RESULTS

The mean follow-up was 3 years. Ten patients (77%) had more than 60% reduction in perceived pruritus of which 4 had more than an 80% reduction. Median [25-75% percentiles] VAS score before and after treatment decreased from 8.0 [8.0-10] to 2.0 [1.5-2.1] (p<0.001). The mean number of irradiations required to obtain this effect was 26 ± 17 (average duration of phototherapy: 8 weeks). No significant changes in cholestatic serum markers were observed. Four patients (30%) needed an additional phototherapy course because of recurrent pruritus and in all of them again a marked improvement of pruritus was observed. The therapy was well tolerated, except in two patients who developed, during retreatment, pronounced erythema in one case and paresthesia in the other case.

CONCLUSIONS

UVB phototherapy appears to be a promising and well tolerated treatment also for cholestasis-associated pruritus.

Management of primary sclerosing cholangitis: conventions and controversies

Primary sclerosing cholangitis (PSC) is a chronic inflammatory cholangiopathy that results in fibrotic strictures and dilations of the intra- and extrahepatic bile ducts. PSC is uncommon, occurs predominantly in males and has a strong association with inflammatory bowel disease. While the pathogenesis of PSC has not been fully elucidated, emerging evidence supports roles for the innate and adaptive immune systems, and genome-wide analyses have identified several genetic associations. Using the best available evidence, the present review summarizes the current understanding of the diagnosis, pathogenesis and management of PSC. Despite its rarity, there is an urgent need for collaborative research efforts to advance therapeutic options for PSC beyond liver transplantation.

Pathogenesis and management of pruritus in cholestatic liver disease

Patients with cholestatic liver diseases such as primary biliary cirrhosis, primary sclerosing cholangitis and intrahepatic cholestasis of pregnancy commonly complain of pruritus. The underlying pathogenesis remains obscure with several mediators possibly playing an important role; these include lysophosphatidic acid, bile salts, opioids, histamine and progesterone metabolites. We describe in this review novel insights into the pathogenesis and management of pruritus in patients with cholestasis.

Molecular Adsorbents Recirculating System dialysis in children with cholestatic pruritus

BACKGROUND

Cholestatic pruritus may severely compromise quality of life. The Molecular Adsorbents Recirculating System (MARS) allows removal of pruritogenic substances without exposure to foreign proteins. Pediatric data, however, are scant.

METHODS

We retrospectively analyzed the efficacy of MARS in three boys with severe cholestatic pruritus. They received a total of 135 MARS sessions during 8, 4, and 13 months prior to liver transplantation. Total serum bilirubin and bile acids were monitored, and pruritus was assessed by a numerical rating scale (NRS 0 = no pruritus, 10 = maximal pruritus).

RESULTS

MARS sessions were initially performed three times weekly at a mean duration of 6.3 ± 1.4 h. Sessions could be reduced to once weekly and once every other week in two patients. Pre-MARS plasma bile acid concentrations averaged 207 ± 67 μmol/l. They declined to 67 ± 9%, 48 ± 3%, 38 ± 14%, and 37 ± 5% of baseline within 2, 4, 6 and 8 h of therapy, respectively (all p < 0.05). The average interdialytic increase of plasma bile acids was 34 ± 33 μmol/l per day. Mean NRS score decreased from 6.5 ± 2.3 to 3.3 ± 2.9 (p < 0.01). Skin lesions from itching disappeared. All MARS treatments were well tolerated.

CONCLUSION

MARS dialysis substantially reduces cholestatic pruritus in children refractory to pharmacological treatment.

Pruritus in chronic cholestatic liver disease

Pruritus is a troublesome complication in patients with cholestatic liver disease. Several links to its pathogenesis have been proposed, including the role of bile acids, endogenous opioid and serotonins, and lysophosphatidic acid. The management of pruritus in cholestasis is challenging. Medical treatment of the underlying cholestatic condition may provide benefit. Extracorporeal albumin dialysis can be pursued for those who have a poor quality of life and failed the various therapeutic interventions, while awaiting liver transplantation. Experimental interventions, and the management of pruritus in certain conditions such as intrahepatic cholestasis of pregnancy and benign recurrent intrahepatic cholestasis, are also briefly reviewed.

'Out-patient' albumin dialysis for cholestatic patients with intractable pruritus

BACKGROUND

Intractable pruritus is a major problem for some patients with cholestasis. Albumin dialysis has been shown to ameliorate pruritus, but long-term outcome data are limited.

AIM

To evaluate the safety and efficacy of 'out-patient' albumin dialysis using the molecular adsorbent recirculating system (MARS) in the treatment of intractable pruritus in cholestatic patients referred for liver transplantation for symptomatic relief.

METHODS

Fifteen patients who failed to respond to standard medical therapy to control pruritus were included. Three MARS (6 h) sessions were performed per admission, and were repeated, if necessary. The intensity and severity of itch was quantified using itch severity and visual analogue scales (ISS and VAS).

RESULTS

Molecular adsorbent recirculating system treatment was safe and associated with immediate and complete response in 11 patients; two patients had a partial response and two patients had no response. Thirty-four treatments were performed during a follow-up period of 15.7 months (3-46) with patients requiring a mean of two admissions (1-6). The mean VAS and ISS improved significantly (both P < 0.001) with improvement in the patient's perception of their quality of life. The duration of acceptable relief in responders was 3.3 months (range 2-5). No serious adverse events were recorded, but the platelet count and haemoglobin were reduced significantly.

CONCLUSION

Molecular adsorbent recirculating system therapy delivered in an 'out-patient' setting is safe and effective with a high degree of patient acceptability. Albumin dialysis can be considered a viable therapeutic option for patients with severe intractable pruritus, in whom, the only other effective treatment option is liver transplantation.

The itch of liver disease

Itch is a complication of liver disease. It is hypothesized that this type of itch is mediated, at least in part, by increased central opioidergic tone; a peripheral component may coexist. The role of serotonin, bile acids, substance P, and lipophosphatidic acid and the activity of the enzyme that generates it, autotoxin, has been proposed in the pathogenesis of itch. Scratching activity was significantly suppressed in association with the placebo tablet in a controlled, double-blind study; this finding supports the exploration of the placebo effect on the itch sensation and the inclusion of behavioral methodology in clinical trials in patients with this complication of liver disease.

Artificial extracorporeal liver support therapy in patients with severe liver failure

Severe liver failure is common and carries a high mortality risk in patients with both acute and acute-on-chronic liver failure. The failing liver constitutes a medical emergency, and in many cases liver transplantation is the only definite treatment. Extracorporeal liver support can be employed as a strategy for bridging to transplantation or recovery. This article focuses on options for artificial (nonbiological) extracorporeal treatment: single-pass albumin dialysis, fractionated plasma separation and adsorption (Prometheus(®)) and the molecular adsorbent recirculatory system. Their different principles, potential advantages and indications are discussed. Despite proven biochemical efficacy, there are little data regarding clinical end points. Thus far, molecular adsorbent recirculatory system therapy in acute and acute-on-chronic liver failure showed no survival benefit compared with standard medical therapy. Prometheus therapy showed reduced mortality in subgroups of higher severity of disease compared with standard medical therapy. Nevertheless, the value of extracorporeal liver support remains to be corroborated by further clinical studies that include the optimal timing, mode, intensity and duration of this treatment.

Model for end-stage liver disease exceptions in the context of the French model for end-stage liver disease score-based liver allocation system

Model for End-Stage Liver Disease (MELD) score-based allocation systems have been adopted by most countries in Europe and North America. Indeed, the MELD score is a robust marker of early mortality for patients with cirrhosis. Except for extreme values, high pretransplant MELD scores do not significantly affect posttransplant survival. The MELD score can be used to optimize the allocation of allografts according to a sickest first policy. Most often, patients with small hepatocellular carcinomas (HCCs) and low MELD scores receive extra points, which allow them appropriate access to transplantation comparable to the access of patients with advanced cirrhosis and high MELD scores. In addition to patients with advanced cirrhosis and HCC, patients with a number of relatively uncommon conditions have low MELD scores and a poor prognosis in the short term without transplantation but derive excellent benefits from transplantation. These conditions, which correspond to the so-called MELD score exceptions, justify the allocation of a specific score for appropriate access to transplantation. Here we report the conclusions of the French consensus meeting. The goals of this meeting were (1) to identify which conditions merit MELD score exceptions, (2) to list the criteria needed for defining each of these conditions, and (3) to define a reasonable time interval for organ allocation for each MELD exception in the general context of organ shortages. MELD exceptions were discussed in an attempt to reconcile the concepts of transparency, equity, justice, and utility.

Acute-on-chronic liver failure: extracorporeal liver assist devices

PURPOSE OF REVIEW

Acute-on-chronic liver failure (ACLF), a syndrome precipitated by acute liver injury in patients with advanced cirrhosis, is associated with multiorgan dysfunction and high rates of mortality. Liver support systems have been developed in an attempt to improve survival of patients with ACLF by providing a bridge until recovery of the native liver function.

RECENT FINDINGS

Nonbiological devices such as molecular adsorbent recirculating system (MARS) and fractionated plasma separation and adsorption (Prometheus) are effective in improving severe hepatic encephalopathy and cholestasis, have good safety and tolerability profiles and are frequently employed in patients with ACLD; however, randomized controlled trials (RCTs) failed to show improvement in survival. Biologic devices that incorporate hepatic cells in bioreactors are also under development. Recent data from pilot studies suggested improvement in survival rates in some groups of patients with ACLF; however, their effect on patient survival in RCT is still unknown.

SUMMARY

Liver support systems are safe and well tolerated when used in management of patients with ACLF. Their use should continue in controlled clinical trials to explore their role in bridging patients to liver transplantation or recovery in well defined patient groups.

Proteomic analysis of polypeptides captured from blood during extracorporeal albumin dialysis in patients with cholestasis and resistant pruritus

Albumin dialysis using the molecular adsorbent recirculating system (MARS) is a new therapeutic approach for liver diseases. To gain insight into the mechanisms involved in albumin dialysis, we analyzed the peptides and proteins absorbed into the MARS strong anion exchange (SAX) cartridges as a result of the treatment of patients with cholestasis and resistant pruritus. Proteins extracted from the SAX MARS cartridges after patient treatment were digested with two enzymes. The resulting peptides were analyzed by multidimensional liquid chromatography coupled to tandem mass spectrometry. We identified over 1,500 peptide sequences corresponding to 144 proteins. In addition to the proteins that are present in control albumin-derived samples, this collection includes 60 proteins that were specific to samples obtained after patient treatment. Five of these proteins (neutrophil defensin 1 [HNP-1], secreted Ly-6/uPAR-related protein 1 [SLURP1], serum amyloid A, fibrinogen alpha chain and pancreatic prohormone) were confirmed to be removed by the dialysis procedure using targeted selected-reaction monitoring MS/MS. Furthermore, capture of HNP-1 and SLURP1 was also validated by Western blot. Interestingly, further analyses of SLURP1 in serum indicated that this protein was 3-fold higher in cholestatic patients than in controls. Proteins captured by MARS share certain structural and biological characteristics, and some of them have important biological functions. Therefore, their removal could be related either to therapeutic or possible adverse effects associated with albumin dialysis.

Mediators of pruritus during cholestasis

PURPOSE OF REVIEW

Pruritus is a frequent symptom in patients with cholestatic liver diseases. Itching may be excruciating, may seriously impair quality of life and even induce suicidal ideation in the most severe cases.

RECENT FINDINGS

The molecular mechanism of itch signal transduction in cholestasis is largely unclear. It may be caused or potentiated by compounds that accumulate in the circulation during cholestasis, which either directly or indirectly affect signalling in itch fibres. In the past, bile salts and endogenous opioids have been proposed but never been proven to be key factors in itch perception during cholestasis. We have performed a screen for compounds in plasma from patients with various cholestatic conditions for their capacity to activate neuronal cell lines. In these sera, we could identify a potent neuronal activator as lysophosphatidic acid (LPA). LPA is a very potent signalling phospholipid that can activate cells through various LPA receptors. Quite strikingly, samples from itchy cholestatic patients contained higher amounts of LPA. These increased levels of LPA turned out to be caused by elevated levels of serum autotaxin, the enzyme that converts lysophosphatidylcholine into LPA. This is a striking finding, as autotaxin has never been connected to itch perception thus far. We have also shown that LPA, when injected intradermally, caused scratching behaviour in mice.

SUMMARY

On the basis of our results, we hypothesize that during cholestasis expression of autotaxin is induced, which gives rise to increased local formation of LPA near unmyelinated nerve endings of itch fibres. LPA activates these neurons through one of the LPA receptors, which in turn potentiates action potentials along itch fibres leading to the perception of pruritus.

Pathophysiology and current management of pruritus in liver disease

Pruritus is frequently reported by patients with cholestatic hepatobiliary diseases such as primary biliary cirrhosis, primary sclerosing cholangitis, intrahepatic cholestasis of pregnancy and hereditary cholestatic syndromes, but may accompany almost any other liver disease. Increased concentrations of bile salts, histamine, progesterone metabolites or endogenous opioids have been controversially discussed as potential pruritogens in cholestasis in the past. Most recently, novel insights unravelled lysophosphatidic acid (LPA), a potent neuronal activator, as a potential pruritogen in pruritus of cholestasis. Nevertheless, the pathogenesis of pruritus in cholestasis is still not clearly defined and current antipruritic treatment strategies provide relief only in a part of the affected patients. Based on recent experimental and clinical findings, this review outlines the actual insight in pathogenesis of pruritus in cholestasis and summarizes evidence-based and experimental therapeutic interventions for cholestatic patients suffering from itch.

[Primary sclerosing cholangitis: diagnosis, prognosis and treatment]

Primary sclerosing cholangitis is a chronic cholestatic disease characterized by inflammation with fibrosis and obliteration of the intra- and extrahepatic bile ducts. This disease is usually associated with ulcerative colitis. The process of chronic cholestasis eventually leads to biliary cirrhosis. The prevalence of primary sclerosing cholangitis is low in southern Europe but is especially high in Scandinavian countries. The etiopathogenesis is unknown but immune disorders, potential toxic agents or intestinal infections, ischemic injury to the bile ducts, and possibly alterations in hepatobiliary transporters are known to play a role. The disease manifests at the age of approximately 40 years, mainly in men with clinical and laboratory features of cholestasis but may also be asymptomatic. There are specific forms in which the small intrahepatic bile ducts are involved, mainly affecting children, as well as overlap syndromes with autoimmune hepatitis. A form characterized by an increase in IgG4 has been described, which is usually associated with autoimmune pancreatitis. The key diagnostic procedure is endoscopic retrograde cholangiography, although magnetic resonance cholangiography is the first diagnostic procedure that should be used since it is equally informative and non-invasive. Liver biopsy is not essential for diagnosis. Primary sclerosing cholangitis is a progressive disease with a probability of transplant-free survival of 18 years in asymptomatic forms and of 8.5 years in symptomatic forms. Cholangiocarcinoma can result from the disease and confers a poor prognosis. There is no specific treatment although ursodeoxycholic acid improves the biochemical alterations of cholestasis. Liver transplantation is the last therapeutic resort with good results in terms of survival although the disease can recur in the transplanted liver.