Plasma separation and bilirubin adsorption after complicated liver transplantation: a therapeutic approach to excessive hyperbilirubinemia

Genetically Modified Hepatocytes Targeting Bilirubin and Ammonia Metabolism for the Construction of Bioartificial Liver System

Acute liver failure (ALF) is a complex syndrome that impairs the liver's function to detoxify bilirubin, ammonia, and other toxic metabolites. Bioartificial liver (BAL) aims to help ALF patients to pass through the urgent period by temporarily undertaking the liver's detoxification functions and promoting the recovery of the injured liver. We genetically modified the hepatocellular cell line HepG2 by stably overexpressing genes encoding UGT1A1, OATP1B1, OTC, ARG1, and CPS1. The resulting SynHeps-II cell line, encapsulated by Cytopore microcarriers, dramatically reduced the serum levels of bilirubin and ammonia, as demonstrated both in vitro using patient plasma and in vivo using ALF animal models. More importantly, we have also completed the 3-dimensional (3D) culturing of cells to meet the demands for industrialized rapid and mass production, and subsequently assembled the plasma-cell contacting BAL (PCC-BAL) system to fulfill the requirements of preclinical experiments. Extracorporeal blood purification of ALF rabbits with SynHeps-II-embedded PCC-BAL saved more than 80% of the animals from rapid death. Mechanistically, SynHeps-II therapy ameliorated liver and brain inflammation caused by high levels of bilirubin and ammonia and promoted liver regeneration by modulating the nuclear factor κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3) pathways. Also, SynHeps-II treatment reduced cerebral infiltration of neutrophils, reduced reactive oxygen species (ROS) levels, and mitigated hepatic encephalopathy. Taken together, SynHeps-II cell-based BAL was promising for the treatment of ALF patients and warrants clinical trials.

Acute kidney injury spectrum in patients with chronic liver disease: Where do we stand?

Acute kidney injury (AKI) is a common complication of liver cirrhosis and is of the utmost clinical and prognostic relevance. Patients with cirrhosis, especially decompensated cirrhosis, are more prone to develop AKI than those without cirrhosis. The hepatorenal syndrome type of AKI (HRS–AKI), a spectrum of disorders in prerenal chronic liver disease, and acute tubular necrosis (ATN) are the two most common causes of AKI in patients with chronic liver disease and cirrhosis. Differentiating these conditions is essential due to the differences in treatment. Prerenal AKI, a more benign disorder, responds well to plasma volume expansion, while ATN requires more specific renal support and is associated with substantial mortality. HRS–AKI is a facet of these two conditions, which are characterized by a dysregulation of the immune response. Recently, there has been progress in better defining this clinical entity, and studies have begun to address optimal care. The present review synopsizes the current diagnostic criteria, pathophysiology, and treatment modalities of HRS–AKI and as well as AKI in other chronic liver diseases (non-HRS–AKI) so that early recognition of HRS–AKI and the appropriate management can be established.

Early Allograft Dysfunction Is Associated With Higher Risk of Renal Nonrecovery After Liver Transplantation

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Early allograft dysfunction (EAD) identifies allografts with marginal function soon after liver transplantation (LT) and is associated with poor LT outcomes. The impact of EAD on post-LT renal recovery, however, has not been studied. Data on 69 primary LT recipients (41 with and 28 without history of renal dysfunction) who received renal replacement therapy (RRT) for a median (range) of 9 (13-41) days before LT were retrospectively analyzed. Primary outcome was renal nonrecovery defined as RRT requirement 30 days from LT. Early allograft dysfunction developed in 21 (30%) patients, and 22 (32%) patients did not recover renal function. Early allograft dysfunction was more common in the renal nonrecovery group (50% vs 21%, P = 0.016). Multivariate logistic regression analysis demonstrated that EAD (odds ratio, 7.25; 95% confidence interval, 2.0-25.8; P = 0.002) and baseline serum creatinine (odds ratio, 3.37; 95% confidence interval, 1.4-8.1; P = 0.007) were independently associated with renal nonrecovery. History of renal dysfunction, duration of renal dysfunction, and duration of RRT were not related to renal recovery (P > 0.2 for all). Patients who had EAD and renal nonrecovery had the worst 1-, 3-, and 5-year patient survival, whereas those without EAD and recovered renal function had the best outcomes (P < 0.001). Post-LT EAD was independently associated with renal nonrecovery in LT recipients on RRT for a short duration before LT. Furthermore, EAD in the setting of renal nonrecovery resulted in the worst long-term survival. Measures to prevent EAD should be undertaken in LT recipients on RRT at time of LT.

Bile cast nephropathy in a patient with cholangiocarcinoma - a case report

Bile cast nephropathy is characterized by the presence of bile casts associated with renal failure and/or proximal tubulopathy in cases of severe hyperbilirubinemia. The clinician should carefully examine the urine samples for characteristic bile‐stained granular casts in suspected case.

A comparison among three different apheretic techniques for treatment of hyperbilirubinemia

Liver failure is associated to high mortality due to the accumulation of protein-bound metabolites, such as bilirubin, not removed by conventional hemodialysis. Different methods can efficiently remove them, such as the molecular adsorbent recirculating system (MARS), plasma exchange (PEX), and bilirubin or plasma adsorption perfusion (PAP). No direct comparison exists between MARS, PEX and PAP, and current guidelines do not specify which method (and when) to use. We have retrospectively evaluated MARS, PEX and PAP in their effectiveness in lowering plasma bilirubin concentration, and their effects on liver and kidney function. A total of 98 patients have been recruited, which comprised 68 patients treated with PAP (177 sessions), 16 patients with PEX (41 sessions) and 11 patients with MARS (21 sessions). Bilirubin, creatinine, liver enzymes were analyzed before and after the first treatment with each technique. The three methods did not differ for bilirubin lowering efficiency, with MARS showing only slightly less effective reductions. Finally, the three techniques did not differ in the amount of change of cholinesterase, but a lower reduction in AST was found using PAP. Our retrospective observation is one of the largest case series of hepatic failure treated with bilirubin absorption. The choice of the technique cannot be based on the desired reduction in bilirubin concentration. Based on costs and duration of treatment, we suggest that PAP could be considered as a first-line approach. In case of kidney involvement, MARS remains a valuable option.

Early Allograft Dysfunction After Liver Transplantation Is Associated With Short- and Long-Term Kidney Function Impairment

Early allograft dysfunction (EAD) after liver transplantation (LT) is related to ischemia-reperfusion injury and may lead to a systemic inflammatory response and extrahepatic organ dysfunction. We evaluated the effect of EAD on new-onset acute kidney injury (AKI) requiring renal replacement therapy within the first month and end-stage renal disease (ESRD) within the first year post-LT in 1325 primary LT recipients. EAD developed in 358 (27%) of recipients. Seventy-one (5.6%) recipients developed AKI and 38 (2.9%) developed ESRD. Compared with those without EAD, recipients with EAD had a higher risk of AKI and ESRD (4% vs. 9% and 2% vs. 6%, respectively, p < 0.001 for both). Multivariate logistic regression analysis showed an independent relationship between EAD and AKI as well as ESRD (odds ratio 3.5, 95% confidence interval 1.9-6.4, and odds ratio 3.1, 95% confidence interval 11.9-91.2, respectively). Patients who experienced both EAD and AKI had inferior 1-, 3-, 5-, and 10-year patient and graft survival compared with those with either EAD or AKI alone, while those who had neither AKI nor EAD had the best outcomes (p < 0.001). Post-LT EAD is a risk factor for both AKI and ESRD and should be considered a target for future intervention to reduce post-LT short- and long-term renal dysfunction.

Hepatorenal syndrome: the 8th International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group

Introduction

Renal dysfunction is a common complication in patients with end-stage cirrhosis. Since the original publication of the definition and diagnostic criteria for the hepatorenal syndrome (HRS), there have been major advances in our understanding of its pathogenesis. The prognosis of patients with cirrhosis who develop HRS remains poor, with a median survival without liver transplantation of less than six months. However, a number of pharmacological and other therapeutic strategies have now become available which offer the ability to prevent or treat renal dysfunction more effectively in this setting. Accordingly, we sought to review the available evidence, make recommendations and delineate key questions for future studies.

Methods

We undertook a systematic review of the literature using Medline, PubMed and Web of Science, data provided by the Scientific Registry of Transplant Recipients and the bibliographies of key reviews. We determined a list of key questions and convened a two-day consensus conference to develop summary statements via a series of alternating breakout and plenary sessions. In these sessions, we identified supporting evidence and generated recommendations and/or directions for future research.

Results

Of the 30 questions considered, we found inadequate evidence for the majority of questions and our recommendations were mainly based on expert opinion. There was insufficient evidence to grade three questions, but we were able to develop a consensus definition for acute kidney injury in patients with cirrhosis and provide consensus recommendations for future investigations to address key areas of uncertainty.

Conclusions

Despite a paucity of sufficiently powered prospectively randomized trials, we were able to establish an evidence-based appraisal of this field and develop a set of consensus recommendations to standardize care and direct further research for patients with cirrhosis and renal dysfunction.

Potential benefits of plasma exchange by apheresis on the treatment of severe Icteric Leptospirosis: case report and literature review

The role of plasmapheresis on the treatment of Leptospirosis has not been define, although it has already been used with beneficial effects in the reported case mentioned above, where was possible to contribute to the resolution of the toxic effects on the tubular renal cells. This case report show how plasma exchange prevents the multiorganic failure.

Albumin regeneration in liver support-comparison of different methods

Albumin is the most abundant human plasma protein. Among many other functions it is an important transporter of hydrophobic internal and external substances such as intermediate and end products of metabolism and drugs. In liver failure the albumin binding capacity is decreased because of a disproportion between available albumin molecules caused by decreased hepatic synthesis and hydrophobic toxins because of decreased hepatic clearance. The resulting increase in plasma and tissue concentrations of these substances is associated with multiple organ dysfunctions frequently seen in severe liver failure. The scope of the present article is to compare different liver support strategies with regard to their ability to regenerate the patients albumin pool by removing albumin-bound toxins. Most prominent technique in this group is the molecular adsorbent recirculating system (MARS). It will be compared with single pass albumin dialysis (SPAD), fractionated plasma separation and adsorption system (FPSA, Prometheus), and plasma perfusion/bilirubin adsorption with special regard to efficacy and selectivity.

Bilirubin-adsorption in 23 critically ill patients with liver failure

PURPOSE

Previous studies suggest that high levels of bilirubin exert cytotoxic, neurotoxic and encephalopathic effects that themselves may lead to further deterioration of liver function and multiorgan failure. Although extracorporeal BA is not a causal therapy, there are case reports of clinical benefits of BA. The present retrospective study investigated the clinical utility and effectiveness of BA in 23 patients with liver failure.

METHODS

Twenty-three patients (61+/-11 years) with excessive hyperbilirubinemia (>25 mg/dL) after liver transplantation (n=7), partial liver resection (n=12) and others (n=4) were treated with BA (3.6 liters plasma per BA, BR350, Asahi) and followed for 45+/-8 days.

RESULTS

A mean of 6.6 treatments (3-16) were performed per patient. On average, a single BA treatment reduced bilirubin-levels from 31+/-12 to 23.7+/-9 mg/dL (p<0.001). Levels of bile acid were reduced from 41.8+/-6 to 33.5+/-5 mg/dL. The 30-day mortality was 50%. BA was able to halt and stabilize the progressive increase in bilirubin levels in all patients. In contrast to survivors, non-survivors were characterized by a repeated rapid rise in bilirubin levels after cessation of BA treatment.

CONCLUSIONS

BA is able to stabilize or decrease bilirubin levels in patients with liver failure. Our experience suggests that BA is a safe and promising short-term treatment option for patients with acute deterioration of hepatic function.

Marked hyperbilirubinemia caused by acute cellular rejection combined with preservation injury in an infant undergoing living-related liver transplantation

Acute cellular rejection (ACR) and preservation injury (PI) are major complications occurring early after liver transplantation (LTx) and sometimes lead to severe graft dysfunction. We herein report an infant who developed marked hyperbilirubinemia as a result of combined ACR and PI in addition to ischemic damage from bleeding, but recovered without re-LTx. In a 1-yr-old-girl undergoing living-related LTx, liver biopsy (LBx) on post-operative day 7 showed ballooning of the hepatocytes, i.e. microvesicular steatosis (30%) and occasional centrolobular necrosis, consistent with mild-to-moderate PI and ACR with a rejection activity index (RAI) of 2.0. Because drainage of an intra-abdominal abscess was performed and a systemic infection was considered severe, the tacrolimus level was decreased and steroids were discontinued. The total bilirubin level started to rise, thereafter, reaching a maximum of 47.6 mg/dL at 1 month after LTx. LBx showed an RAI of 6.0 and steatosis of 10%. With good response to an increase of tacrolimus level and administration of steroid, the total bilirubin level gradually decreased, finally reaching the normal range in 3 months, and LBx showed no steatosis or finding of ACR. From this experience, ACR, if combined with mild-to-moderate PI or other ischemic damage, may lead to severe clinical manifestations after LTx, which, however, could remit with conservative therapy and without re-LTx.

Potential benefit of plasma exchange in treatment of severe icteric leptospirosis complicated by acute renal failure

Leptospirosis is a common zoonosis seen worldwide, but it is rare in our locality (Hong Kong). Clinical manifestations of leptospirosis are variable and may range from subclinical infection to fever, jaundice, hemorrhagic tendency, and fulminant hepato-renal failure. Severe hyperbilirubinemia and acute renal failure have been associated with high mortality. We report our experience with a patient who developed severe Weil's syndrome with marked conjugated hyperbilirubinemia and oliguric acute renal failure. These complications persisted despite treatment with penicillin and hemodiafiltration. Plasma exchange was instituted in view of the severe hyperbilirubinemia (970 micromol/liter). This was followed by prompt clinical improvement, with recovery of liver and renal function. The beneficial effects of plasma exchange could be attributed to amelioration of the toxic effects of hyperbilirubinemia on hepatocyte and renal tubular cell function. We conclude that plasma exchange should be considered as an adjunctive therapy for patients with severe icteric leptospirosis complicated by acute renal failure who have not shown rapid clinical response to conventional treatment.

Functional metabolic characteristics of intact pig livers during prolonged extracorporeal perfusion: potential for a unique biological liver-assist device

BACKGROUND

The clinical development of liver-support devices based on perfusion of either pig hepatocytes cartridges or whole pig livers has been hampered by the ability to use sufficient liver cell mass to provide adequate metabolic support, limited perfusion times, and the potential for patient exposure to pig zoonotic diseases.

METHODS

We designed an original system in which an isolated intact pig liver was perfused extracorporeally under physiological conditions in a closed loop circuit with allogeneic pig blood and constant monitoring of major physiological and functional parameters. The perfusion circuit further included an interface membrane to provide for separation of patient and liver perfusion circulation.

RESULTS

Prolonged (6-21 hr) liver perfusion did not produce significant liver damage as reflected by modest rises in the levels of the serum transaminases, stability of main biochemical parameters (including potassium), and the maintenance of normal cellular morphology. Optimal liver function was documented as measured by lactate consumption, control of glycemia, and the results of clotting studies and functional assays. The perfused liver cleared 82% and 79% of peak bilirubin and ammonia concentrations with clearing kinetics identical throughout perfusion. Indocyanine green clearance was identical to that observed in the living donor before explant surgery.

CONCLUSIONS

In conclusion, the extracorporeal pig liver perfusion apparatus described here allows optimal pig liver function for prolonged periods of time. The microporous membrane to provide separation of donor organ and recipient and the high level of functional activity suggest that this form of liver metabolic support may have important clinical applications.