Study of plasma exchange for liver failure: beneficial and harmful effects

Management of pediatric liver failure with therapeutic plasma exchange and continuous renal replacement therapy: A retrospective observational study

Liver failure represents a critical medical condition, marked by the rapid decline of hepatic functions. Emerging therapies, notably therapeutic plasma exchange (TPE) and continuous venovenous hemodiafiltration (CVVHDF), have demonstrated potential in mitigating these conditions through their roles in detoxification and hepatic support. The utility of these treatments, whether applied individually or in tandem, constitutes a significant area of research concerning the management of liver failure in pediatric patients. This study aims to evaluate the role and efficacy of TPE or TPE combined with CVVHDF in the treatment of liver failure among children. This retrospective study was conducted in a LTICU by reviewing the medical history of pediatric patients aged 1 month to 18 years. Patients were admitted between January 1, 2021 and December 1, 2023 due to acute liver failure or acute-chronic liver failure. The study evaluated those who received TPE or continuous renal replacement therapy combined with TPE. In statistical analyses, a P-value of <.05 was considered statistically significant. The study involved 24 patients with liver failure, comprising 13 males and 11 females. Sixteen patients (66.6%) received only TPE, while 8 patients (33.4%) were treated with TPE and CVVHDF. For patients treated only with TPE, the median INR reduced from 3.1 to 1.26, alanine aminotransferase from 1255 to 148, and aspartate aminotransferase from 2189 to 62. Similar significant reductions were observed in the TPE and CVVHDF group: INR from 3.9 to 1.26, alanine aminotransferase from 1749 to 1148, and aspartate aminotransferase from 1489 to 62. These changes were statistically significant with P-values of .01 for each parameter in both groups. Overall, 14 patients survived without requiring a liver transplant, while 4 patients underwent liver transplantation. Our study on pediatric liver failure treatment shows that both standalone TPE and its combination with CVVHDF are effective, especially as a bridge to transplantation. With 58% transplant-free survival, these therapies demonstrate significant clinical improvements. Future multicentric studies are needed for broader validation of these findings in liver failure management.

Characteristics of circulating immune cells in HBV-related acute-on-chronic liver failure following artificial liver treatment

BACKGROUND AND AIM

Liver failure, which is predominantly caused by hepatitis B (HBV) can be improved by an artificial liver support system (ALSS). This study investigated the phenotypic heterogeneity of immunocytes in patients with HBV-related acute-on-chronic liver failure (HBV-ACLF) before and after ALSS therapy.

METHODS

A total of 22 patients with HBV-ACLF who received ALSS therapy were included in the study. Patients with Grade I according to the ACLF Research Consortium score were considered to have improved. Demographic and laboratory data were collected and analyzed during hospitalization. Immunological features of peripheral blood in the patients before and after ALSS were detected by mass cytometry analyses.

RESULTS

In total, 12 patients improved and 10 patients did not. According to the immunological features data after ALSS, the proportion of circulating monocytes was significantly higher in non-improved patients, but there were fewer γδT cells compared with those in improved patients. Characterization of 37 cell clusters revealed that the frequency of effector CD8+ T (P = 0.003), CD4+ TCM (P = 0.033), CD4+ TEM (P = 0.039), and inhibitory natural killer (NK) cells (P = 0.029) decreased in HBV-ACLF patients after ALSS therapy. Sub group analyses after treatment showed that the improved patients had higher proportions of CD4+ TCM (P = 0.010), CD4+ TEM (P = 0.021), and γδT cells (P = 0.003) and a lower proportion of monocytes (P = 0.012) compared with the non-improved patients.

CONCLUSIONS

Changes in effector CD8+ T cells, effector and memory CD4+ T cells, and inhibitory NK cells are associated with ALSS treatment of HBV-ACLF. Moreover, monocytes and γδT cells exhibited the main differences when patients obtained different prognoses. The phenotypic heterogeneity of lymphocytes and monocytes may contribute to the prognosis of ALSS and future immunotherapy strategies.

Extracorporeal renal and liver support in pediatric acute liver failure

The liver is the only organ which can regenerate and, thus, potentially negate the need for transplantation in acute liver failure (ALF). Cerebral edema and sepsis are leading causes of mortality in ALF. Both water-soluble and protein-bound toxins have been implicated in pathogenesis of various ALF complications. Ammonia is a surrogate marker of water-soluble toxin accumulation in ALF and high levels are associated with higher grades of hepatic encephalopathy, raised intracranial pressure, and mortality. Therefore, extracorporeal therapies aim to lower ammonia and maintain fluid balance and cytokine homeostasis. The most common and easily available modality is continuous kidney replacement therapy (CKRT). Early initiation of high-volume CKRT utilizing an anticoagulation regimen minimizing treatment downtime and delivering the prescribed dose is highly desirable. Ideally, extracorporeal liver-assist devices (ECLAD) should perform both synthetic and detoxification functions of the liver. ECLAD may temporarily replace lost liver function and serve as a bridge, either to spontaneous recovery or liver transplantation. Various bioartificial and biologic liver-assist devices are described in specialty literature, including molecular adsorbent recirculating system (MARS), single pass albumin dialysis (SPAD), and total plasma exchange (TPE); however, clinicians commonly use modalities easily available in intensive care units. There is a lack of standardization of indications for ECLAD, availability of different extracorporeal devices with varied technical approaches, and, of note, the differences in doses of ECLAD provided in clinical practice. We review the practicalities and evidence regarding these four artificial liver support devices in pediatric ALF.

Artificial liver support systems

Artificial liver systems are used to bridge between transplantation or to allow a patient's liver to recover. They are used in patients with acute liver failure (ALF) and acute-on-chronic liver failure. There are five artificial systems currently in use: molecular adsorbent recirculating system (MARS), single-pass albumin dialysis (SPAD), Prometheus, selective plasma filtration therapy, and hemodiafiltration. The aim is to compare existing data on the efficiency of these devices. A literature search was conducted using online libraries. Inclusion criteria included randomized control trials or comparative human studies published after the year 2000. A systematic review was conducted for the five individual devices with a more detailed comparison of the biochemistry for the SPAD and MARS systems. Eighty-nine patients were involved in the review comparing SPAD and MARS. Results showed that there was an average reduction in bilirubin (-53 μmol/L in MARS and -50 μmol/L in SPAD), creatinine (-19.5 μmol/L in MARS and -7.5 μmol/L in SPAD), urea (-0.9 mmol/L in MARS and -0.75 mmol/L in SPAD), and gamma-glutamyl transferase (-0.215 μmol/L·s in MARS and -0.295 μmol/L·s in SPAD) in both SPAD and MARS. However, there was no significant difference between the changes in the two systems. This review demonstrated that both MARS and SPAD aid recovery of ALF. There is no difference between the efficiency of MARS and SPAD. Because of the limited data, there is a need for more randomized control trials. Evaluating cost and patient preference would aid in differentiating the systems.

Changes from 2012 to 2015 in intravenous fluid solutions issued to hospital departments

BACKGROUND

In recent years, large trials have increased the level of evidence for intravenous (IV) fluid therapy, at least in the intensive care setting. It is less clear whether this change in the evidence base has been associated with changes in IV fluid use in different hospital departments.

METHODS

We obtained details from the regional pharmacy regarding IV fluids issued to hospital departments in the Danish Capitol Region from January 2012 to May 2015. We used paired Wilcoxon's signed-rank test to analyse changes in the issuing in different departments.

RESULTS

Total regional issuing of IV fluids showed increase in crystalloid solutions (9%; P = 0.001) and decrease in colloid solutions (59%; P = 0.005). Subtype analysis showed increased issuing of buffered crystalloids (36%; P = 0.001), human albumin (30%; P < 0.0001) and decreased issuing in synthetic colloid solutions (82%; P < 0.0001) from Q1 2012 to Q2 2015. At the departmental level, the issuing of synthetic colloid solutions decreased markedly to all settings. The issuing of buffered crystalloids increased to orthopaedic (226%; P = 0.03) and to general surgery departments (686%; P = 0.002). Albumin solutions were increasingly issued to anaesthesia departments (63%; P = 0.005) and was rarely issued to general surgery and orthopaedic departments.

CONCLUSIONS

The issuing of IV fluid solutions to hospital departments has changed markedly over the last years to less colloid, in particular the synthetic solutions, and relatively more issuing of crystalloids, in particular the buffered solutions.

Advanced therapeutic strategies for HBV-related acute-on-chronic liver failure

BACKGROUND

Acute-on-chronic liver failure (ACLF) is increasingly recognized as a distinct clinical entity and is associated with a high short-term mortality. The most common cause of ACLF is chronic hepatitis B worldwide. Currently, there is no standardized approach for the management of ACLF and the efficacy and safety of therapeutic modalities are uncertain.

DATA SOURCES

PubMed and Web of Science were searched for English-language articles. The search criteria focused on clinical trials and observational studies on the treatment of patients with HBV-related ACLF.

RESULTS

Therapeutic approaches for ACLF in patients with chronic hepatitis B included nucleos(t)ide analogues, artificial liver support systems, immune regulatory therapy, stem cell therapy and liver transplantation. All of these therapeutic approaches have shown the potential to improve liver function and increase patients' survival rate, but most of the studies were not randomized or controlled.

CONCLUSION

Substantial challenges for the treatment of HBV-related ACLF remain and further basic research and randomized controlled clinical trials are needed.

Efficacy of coupled low-volume plasma exchange with plasma filtration adsorption in treating pigs with acute liver failure: A randomised study

BACKGROUND & AIMS

Extracorporeal blood purification systems for supportive therapy of liver failure are widely used. We developed a novel blood purification system, named Li's artificial liver system (Li-ALS), which couples low-volume plasma exchange (low-volume PE) with plasma filtration adsorption (PFA). This study aims to evaluate the efficacy of our novel system in pigs with acute liver failure (ALF).

METHODS

Thirty-two pigs were infused with D-galactosamine (1.3g/kg) to induce ALF. All animals were equally and randomly divided into four groups: the ALF control group received intensive care, the PFA group underwent five hour plasma recycling filtration and adsorption purification, the low-volume PE group received one hour low-volume PE, and the Li-ALS group underwent one hour low-volume PE, followed by five hour PFA. Intervention was initiated 36hours after drug administration. The efficacy of each treatment was assessed by survival time and improvement in hematological, biochemical, and immunohistological parameters.

RESULTS

Pigs in the Li-ALS group survived longer than those in the other groups (p<0.001, ALF control: 60±2h; PFA group: 74±2h; low-volume PE group: 75±2h; and Li-ALS group: 90±3h). Liver enzyme, bilirubin, bile acid and blood ammonia levels were decreased significantly after Li-ALS treatment, and increases in inflammatory cytokines were ameliorated. A higher hepatocyte regeneration index was also observed in the Li-ALS group.

CONCLUSION

Our novel Li-ALS could expedite liver regeneration and improve survival time; hence, it could be promising for treating ALF.

Initial combination anti-viral therapy with lamivudine and adefovir dipivoxil decreases short-term fatality rate of hepatitis-B-virus-related acute-on-chronic liver failure. Virol J. 2015;12:97. [PMID: 26104153 PMCID: PMC4501091 DOI: 10.1186/s12985-015-0323-3]

Background

Acute-on-chronic liver failure (ACLF) is a common serious hepatitis B virus (HBV)-related disease and has a poor prognosis. Until recently, initial combination antiviral treatment in ACLF patients was rarely reported. This study evaluated the effect of initial combination treatment with lamivudine and adefovir dipivoxil on the prognosis of HBV-related ACLF.

Methods

In this retrospective study, 131 eligible ACLF patients, including 61 treated with 100 mg lamivudine and 10 mg adefovir dipivoxil daily and 70 not treated with any nucleoside analogs (NAs), were selected and assigned into the NA and non-NA groups. All the patients received standard medicinal therapy. At weeks 0–4 and 12, serum markers for hepatic and renal functions were measured in all patients and accumulated fatality rates were calculated. Statistical analyses, including Student’s t test, χ² test and unconditional logistic regression analysis, were performed using SPSS version 17.0 software.

Results

Clinical data indicated that improvement of hepatic function was better in the NA than in the non-NA group. The accumulated fatality rate in the NA group was lower than in the non-NA group at weeks 2–4 and 12, and these differences were significant. Univariate analysis showed that age, prothrombin activity, model of end-stage liver disease (MELD) score, and treatment without NAs were risk factors for short-term survival of ACLF. Further research by unconditional logistic regression analysis identified that older age, high MELD score and treatment without NAs were independent risk factors for short-term survival of ACLF.

Conclusions

Initial combination antiviral treatment is effective in decreasing short-term fatality of HBV-related ACLF.

Liver dialysis in acute-on-chronic liver failure: current and future perspectives

Patients with acute-on-chronic liver failure (ACLF) are known to have a very high mortality rate as the majority of these patients succumb to multiorgan failure. Liver transplant remains the only option for these patients; however, there are problems with its availability, cost and also the complications and side effects associated with immunosuppression. Unlike advanced decompensated liver disease, there is a potential for hepatic regeneration and recovery in patients with ACLF. A liver support system, cell or non-cell based, logically is likely to provide temporary functional support until the donor liver becomes available or the failing liver survives the onslaught of the acute insult and spontaneously regenerates. Understanding the pathogenesis of liver failure and regeneration is essential to define the needs for a support system. Removal of hepatotoxic metabolites and inhibitors of hepatic regeneration by liver dialysis, a non-cell-based hepatic support, could help to provide a suitable microenvironment and support the failing liver. The current systems, i.e., MARS and Prometheus, have failed to show survival benefits in patients with ACLF based on which newer devices with improved functionality are currently under development. However, larger randomized trials are needed to prove whether these devices can enable restoration of the complex dysregulated immune system and impact organ failure and mortality in these patients.

Extracorporeal detoxification for hepatic failure using molecular adsorbent recirculating system: depurative efficiency and clinical results in a long-term follow-up

Acute liver failure and acute-on-chronic liver failure still show a poor prognosis. The molecular adsorbent recirculating system (MARS) has been extensively used as the most promising detoxifying therapy for patients with these conditions. Sixty-four patients with life-threatening liver failure were selected, and 269 MARS treatments were carried out as a bridge for orthotopic liver transplantation (OLT) or for liver function recovery. All patients were grouped according to the aim of MARS therapy. Group A consisted of 47 patients treated for liver function recovery (median age 59 years, range 23-82). Group B consisted of 11 patients on the waiting list who underwent OLT (median age 47 years, range 32-62). Group C consisted of 6 patients on the waiting list who did not undergo OLT (median age 45.5 years, range 36-54, P = 0.001). MARS depurative efficiency in terms of liver toxins, cytokines, and growth factors was assessed together with the clinical outcome of the patients during a 1-year follow-up. Total bilirubin reduction rate per session (RRs) for each MARS session was 23% (range 17-29); direct bilirubin RRs was 28% (21-35), and indirect bilirubin RRs was 8% (3-21). Ammonia RRs was 34% (12-86). Conjugated cholic acid RRs was 58% (48-61); chenodeoxycholic acid RRs was 34% (18-48). No differences were found between groups. Hepatocyte growth factor (HGF) values on starting MARS were 4.1 ng/mL (1.9-7.9) versus 7.9 ng/mL (3.2-14.1) at MARS end (P < 0.01). Cox regression analysis to determine the risk factors predicting patient outcomes showed that age, male gender, and Sequential Organ Failure Assessment score (but not Model for End-stage Liver Disease score) were factors predicting death, whereas the number of MARS sessions and the ΔHGF proved protective factors. Kaplan-Meier survival analysis was also used; after 12 months, 21.3% of patients in Group A survived, while 90.9% were alive in Group B and 16.7% in Group C (log rank = 0.002). In conclusion, MARS was clinically well tolerated by all patients and significantly reduced hepatic toxins. Better survival rates were linked to an OLT program, but patients' clinical characteristics on starting MARS therapy were the main factors predicting survival. The role of HGF should be evaluated in larger clinical trials.

Advances in cell sources of hepatocytes for bioartificial liver

BACKGROUND

Orthotopic liver transplantation (OLT) is the most effective therapy for liver failure. However, OLT is severely limited by the shortage of liver donors. Bioartificial liver (BAL) shows great potential as an alternative therapy for liver failure. In recent years, progress has been made in BAL regarding genetically engineered cell lines, immortalized human hepatocytes, methods for preserving the phenotype of primary human hepatocytes, and other functional hepatocytes derived from stem cells.

DATA SOURCES

A systematic search of PubMed and ISI Web of Science was performed to identify relevant studies in English language literature using the key words such as liver failure, bioartificial liver, hepatocyte, stem cells, differentiation, and immortalization. More than 200 articles related to the cell sources of hepatocyte in BAL were systematically reviewed.

RESULTS

Methods for preserving the phenotype of primary human hepatocytes have been successfully developed. Many genetically engineered cell lines and immortalized human hepatocytes have also been established. Among these cell lines, the incorporation of BAL with GS-HepG2 cells or alginate-encapsulated HepG2 cells could prolong the survival time and improve pathophysiological parameters in an animal model of liver failure. The cBAL111 cells were evaluated using the AMC-BAL bioreactor, which could eliminate ammonia and lidocaine, and produce albumin. Importantly, BAL loading with HepLi-4 cells could significantly improve the blood biochemical parameters, and prolong the survival time in pigs with liver failure. Other functional hepatocytes differentiated from stem cells, such as human liver progenitor cells, have been successfully achieved.

CONCLUSIONS

Aside from genetically modified liver cell lines and immortalized human hepatocytes, other functional hepatocytes derived from stem cells show great potential as cell sources for BAL. BAL with safe and effective liver cells may be achieved for clinical liver failure in the near future.

Combined therapy for acute hepatic failure

Acute hepatic failure (AHF) is a devastating clinical syndrome characterized by rapid impairment of liver functions and development of encephalopathy, multiple organ failure, and in most cases cerebral edema. AHF has a high mortality rate. Although advances in drug treatment, artificial liver and liver transplantation have significantly improved the prognosis of AHF, there is still a lack of effective treatment for AHF because of its complicated etiopathogenesis, rapid progression and less clinical knowledge about managing the disease. There is an urgent need to develop effective treatments for AHF. This article aims to review recent advances in the treatment of AHF.

Therapeutic strategies for severe alcoholic hepatitis

BACKGROUND AND AIMS

Severe alcoholic hepatitis (SAH) is an inflammatory response with multiple morbidity factors like leucocytosis, hepatomegaly, renal failure, hepatic encephalopathy, endotoxemia, and has a high mortality rate. Accordingly, identifying therapeutic interventions that can support prognosis is the goal of research.

METHODS

Questionnaires were sent to 1234 medical institutions asking for information on patients with SAH during 2004 to 2008 including patients' demography, disease profile and the therapeutic interventions patients had received during hospitalization.

RESULTS

Twenty-nine hospitals had treated SAH patients, and provided full demographic data on 62 patients. Twenty-seven patients had received no treatment, 10 patients had received granulocytes/monocytes apheresis (GMA) to deplete elevated myeloid linage leucocytes, the rest had received one or more of the following treatments, corticosteroids, plasma exchange (PE) and haemodialysis (HD). Further, 23 patients had died and 39 had survived within 100 days of hospitalization. Serum creatinine (Cr) was higher in patients who had died vs patients who had survived (P=0.026). Likewise, patients with white blood cells (WBC) ≥ 10(4)/μL had higher mortality rate vs patients with WBC<10(4)/μL (P=0.039). GMA in patients with WBC ≥ 10(4)/μL showed 100% prognosis vs patients with WBC ≥ 10(4)/μL who did not receive GMA (P=0.0007). Corticosteroids, PE and HD did not significantly impact prognosis of SAH patients.

CONCLUSIONS

Our perception is that, patients with elevated myeloid leucocytes benefit most from GMA, while PE appears to support patients with coagulation deficiency or high plasma bilirubin and HD has indication in patients with high Cr.

Nucleoside analogue can improve the long-term prognosis of patients with hepatitis B virus infection-associated acute on chronic liver failure

BACKGROUND

The prognosis of patients with hepatitis B virus (HBV)-associated acute on chronic liver failure (ACLF) is extremely poor.

AIM

This study was designed to evaluate the efficacy and safety of nucleoside analogue treatment of patients with HBV-associated ACLF.

METHODS

We used a retrospective review of eligible patients from April 2006 to December 2008. Eligible subjects received 0.5 mg entecavir daily until October 2009 (group A), 100 mg lamivudine daily until October 2009 (group B), or no nucleoside analogue (group C). The primary endpoints were three-month survival and the rate of recurrence of HBV-associated ACLF. The secondary endpoints were HBV DNA levels, liver function, the model of end-stage liver disease (MELD) score, and adverse events.

RESULTS

A total of 104 consecutive patients were recruited, and 33, 34, and 37 patients were randomly allocated to groups A, B, and C, respectively. Although no significant difference in three-month survival was observed, levels of HBV DNA and rates of recurrence of HBV-associated ACLF were lower. Liver function and MELD score were not significantly improved despite significantly reduced HBV DNA levels.

CONCLUSIONS

These data indicated that nucleoside analogue treatment did not improve the short-term prognosis of patients with HBV-associated ACLF although it was efficacious and safe in the management of HBV DNA levels. Intriguingly and importantly, continuous nucleoside analogue treatment can significantly reduce the rate of recurrence, which might be indicative of the further benefit of long-term survival.

Living donor liver transplantation for fulminant hepatic failure

AIM

The aim of this study was to investigate the safety of living donor liver transplantation (LDLT) for fulminant hepatic failure (FHF) patients.

METHODS

We reviewed the clinical indications, operative procedures and prognosis of LDLT performed on patients with FHF at the University of Tokyo. From January 1996 to August 2007, 96 patients were referred to our department due to severe acute hepatitis or FHF. Of these, 36 underwent LDLT and were the subjects of this study. Of the 36 patients who underwent LDLT, 32 were over 18 years old. The etiologies of FHF included non-A, non-B hepatitis in 23, hepatitis B virus in 11, Wilson's disease in one, and auto-immune hepatitis in one. Graft type included right liver in 18, left liver in 16 and right paramedian sector in two.

RESULTS

Patient and graft survival rates at 5 years were 87% and 82%, respectively. Twenty-three patients had postoperative complications: acute cellular rejection in 12, biliary stricture in eight, bile leakage in six, peritoneal hemorrhage in six and hepatic arterial thrombosis in four.

CONCLUSION

The LDLT procedure provided satisfactory survival rates for FHF patients.

Recombinant human hepatocyte growth factor for liver failure

The purpose of this paper is to evaluate the efficacy and safety of recombinant human hepatocyte growth factor (rh-HGF) for liver failure (LF) using meta-analysis of data from the literature involving available randomized controlled trials of rh-HGF plus comprehensive therapy (CT) compared with that of CT alone (Therapy I versus II) in treating LF. We searched the Cochrane Library, MEDLINE, EMBASE, CBMdisc, and CNKI as well as employing manual searches. Based on our search criteria, we found 21 trials, involving 5902 patients. Our results showed that Therapy I, compared with therapy II, significantly reduced the overall mortality (RR=0.62; 95% CI, 0.59-0.66; p=0.0001). Compared to two clinical types of LF (acute and acute-on-chronic), therapy I perhaps had significant effect on mortality due to sub-acute LF, RR and 95% CI were 0.76 [0.65, 0.89], 0.66 [0.60, 0.74], and 0.58 [0.53, 0.64], respectively. Additionally, there was a reduction in mortality of patients that had evidence for an early stage of LF compared to the two other clinical stages of LF (Middle and Advanced); RR and 95% CI were 0.34 [0.24, 0.49], 0.49 [0.44, 0.55], and 0.87 [0.82, 0.93], respectively. No serious adverse events were reported. We conclude that Therapy I may reduce mortality in LF, especially in sub-acute LF and the early stage of LF. However, considering the strength of the evidence, additional randomized controlled trials are needed before Therapy I can be recommended routinely.

A case report of acute renal failure and fulminant hepatitis associated with edaravone administration in a cerebral infarction patient

A 60-year-old male with cerebral infarction was admitted to our hospital and treated with edaravone. On day 12 of hospitalization, he suddenly lost consciousness and went into shock. Based on the laboratory findings, acute renal failure (ARF), fulminant hepatitis, and disseminated intravascular coagulation (DIC) were diagnosed. We immediately initiated continuous hemodiafiltration for three days and performed three sessions of plasma exchange. Following this, a gradual improvement was observed in the patient's general condition and laboratory values. On day 17 of hospitalization, intermittent hemodialysis (HD) was initiated. On day 20 of hospitalization, his renal function started to improve with an increase in urine volume. HD was successfully discontinued on the same day. Although the drug lymphocyte stimulation test for edaravone was negative, edaravone-induced fulminant hepatitis was suggested based on liver biopsy findings. We present a case of ARF, fulminant hepatitis, and DIC due to edaravone administration that was successfully treated with blood purification techniques. Since the use of edaravone treatment is expected to increase in the future, it is essential that clinicians consider the potential adverse effects of this treatment. It is suggested that blood purification is effective in inducing remission in patients with complications due to edaravone treatment.

Construction and transplantation of an engineered hepatic tissue using a polyaminourethane-coated nonwoven polytetrafluoroethylene fabric

BACKGROUND

Acute liver failure (ALF) is a serious condition that has a high mortality rate. Construction of an efficient culture and transplantation engineering system of hepatic tissue is an important approach to treat patients suffering from ALF to provide short-term hepatic support until the damaged liver spontaneously recovers or a donor liver becomes available for transplantation. Here, we evaluate the construction and transplantation of an engineered hepatic tissue (EHT) using primary isolated hepatocytes cultured onto polyaminourethane (PAU)-coated, nonwoven polytetrafluoroethylene (PTFE) fabric.

METHODS

The isolated hepatocytes cultured onto PAU-coated PTFE fabric were able to adhere and spread over the individual fibers of the net and formed hepatic clusters after 3 days, such clusters revealed Gap junctions and well-developed bile canaliculi.

RESULTS

When PAU-coated PTFE was utilized, ammonia-, and diazepam- metabolizing capacities and albumin production ability were significantly increased compared with collagen control. To test the function of this hepatic tissue in vivo, we transplanted a nonwoven PAU-coated PTFE fabric inoculated with one million hepatocytes on the surface of the spleen of Balb/c mice suffering from ALF induced by 90% hepatectomy, and found that this EHT prolonged the survival of liver failure-induced mice without adverse effects. Ultrastructure analyses showed good attachment of the cells on the surface of PTFE fabric and strong albumin expression seven days after the newly formed hepatic tissue was transplanted.

CONCLUSION

We have here demonstrated the efficient construction and transplantation of hepatic tissue using primary hepatocytes and PAU-coated PTFE fabric.

Reversal of mouse hepatic failure using an implanted liver-assist device containing ES cell-derived hepatocytes

Severe acute liver failure, even when transient, must be treated by transplantation and lifelong immune suppression. Treatment could be improved by bioartificial liver (BAL) support, but this approach is hindered by a shortage of human hepatocytes. To generate an alternative source of cells for BAL support, we differentiated mouse embryonic stem (ES) cells into hepatocytes by coculture with a combination of human liver nonparenchymal cell lines and fibroblast growth factor-2, human activin-A and hepatocyte growth factor. Functional hepatocytes were isolated using albumin promoter-based cell sorting. ES cell-derived hepatocytes expressed liver-specific genes, secreted albumin and metabolized ammonia, lidocaine and diazepam. Treatment of 90% hepatectomized mice with a subcutaneously implanted BAL seeded with ES cell-derived hepatocytes or primary hepatocytes improved liver function and prolonged survival, whereas treatment with a BAL seeded with control cells did not. After functioning in the BAL, ES cell-derived hepatocytes developed characteristics nearly identical to those of primary hepatocytes.

Differentiation of human embryonic stem cells to hepatocytes using deleted variant of HGF and poly-amino-urethane-coated nonwoven polytetrafluoroethylene fabric

Human embryonic stem (hES) cells have recently been studied as an attractive source for the development of a bioartificial liver (BAL). Here we evaluate the differentiation capacity of hES cells into hepatocytes. hES cells were subjected to suspension culture for 5 days, and then cultured onto poly-amino-urethane (PAU)-coated, nonwoven polytetrafluoroethylene (PTFE) fabric in the presence of fibroblast growth factor-2 (bFGF) (100 ng/ml) for 3 days, then with deleted variant of hepatocyte growth factor (dHGF) (100 ng/ml) and 1% dimethyl sulfoxide (DMSO) for 8 days, and finally with dexamethasone (10(-7) M) for 3 days. The hES cells showed gene expression of albumin in a time-dependent manner of the hepatic differentiation process. The resultant hES-derived hepatocytes metabolized the loaded ammonia and lidocaine at 7.8% and 23.6%, respectively. A million of such hepatocytes produced albumin and urea at 351.2 ng and urea at 7.0 microg. Scanning electron microscopy showed good attachment of the cells on the surface of the PTFE fabric and well-developed glycogen rosettes and Gap junction. In the present work we have demonstrated the efficient differentiation of hES cells to functional hepatocytes. The findings are useful to develop a BAL.

Clinical Outcome of Thrombotic Microangiopathy after Living-Donor Liver Transplantation Treated with Plasma Exchange Therapy

Thrombotic microangiopathy (TMA) is a well-documented but severe complication that occurs after solid-organ transplant. Administration of calcineurin inhibitors is considered a major cause of this fatal complication; prompt initiation of plasma exchange therapy after reduction or conversion of calcineurin inhibitors has been recommended. Nevertheless, little is known about clinical evidence of this strategy against TMA after solid-organ, especially non-renal-organ, transplantation. Medical records of 63 patients who were hospitalized at Artificial Organ and Transplantation Division in Tokyo University Hospital and underwent blood purification therapy between January 1999 and May 2005 were reviewed. Twenty-eight living-donor liver transplantation (LDLT) recipients who received plasma exchange therapy were identified, and 18 of them were found retrospectively to receive a diagnosis of having TMA. Of the 18 patients, 10 (56%) responded to this therapy and survived after the treatment was stopped, whereas eight (44%) patients died before improvement. Subsequent follow-up of patients clarified that 1-yr survival rate of post-LDLT TMA was approximately 30%. Multivariate Cox proportional-hazards regression analysis demonstrated that the interval between transplant surgery and onset of TMA (hazard ratio 1.35 per 30 d; 95% confidence interval 1.07 to 1.71; P = 0.021) and pretreatment blood urea nitrogen level (hazard ratio 1.39 per 10 mg/dl; 95% confidence interval 1.02 to 1.90; P = 0.037) predicted mortality. Analyses identified post-LDLT recipients with TMA as being at high risk for poor prognosis. Effective strategies are needed for late-onset TMA after LDLT to improve treatment response and survival.

Transplantation of human hepatocytes cultured with deleted variant of hepatocyte growth factor prolongs the survival of mice with acute liver failure

BACKGROUND

Considering the scarcity of donor livers, it is extremely important to establish a functional culture method for isolated hepatocytes. As a tool for maintaining hepatocyte functions in vitro, dHGF, a variant of HGF (hepatocyte growth factor) with a deletion of five amino acids, attracted our attention because it is less cytotoxic compared with HGF.

METHODS

We evaluated growth, albumin production, metabolizing abilities of ammonia, lidocaine, and diazepam of human hepatocytes in the presence of dHGF (10-1000 ng/ml). The gene expression of liver markers was comparatively analyzed. The effect of intrasplenic transplantation of dHGF-treated human hepatocytes into severe combined immunodeficient (SCID) mice was evaluated in an acute liver failure (ALF) model induced by D-galactosamine (D-gal).

RESULTS

When 100 ng/ml of dHGF was utilized, metabolism rates of ammonia, lidocaine, and diazepam and albumin production per unit cell significantly increased. The gene expression analysis demonstrated the enhanced expression of albumin, HNF-4alpha, and C/EBPalpha in the hepatocytes treated with 100 ng/ml of dHGF. Transplantation of such hepatocytes prolonged the survival of the SCID mice with ALF induced by D-gal.

CONCLUSIONS

The present work clearly demonstrates the usefulness of dHGF (100 ng/ml) for maintaining the differentiated functions of human hepatocytes in tissue culture.